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Influence of Nonstoichiometry and the Presence of Maghemite on the Mössbauer Spectrum of Magnetite
- G. M. da Costa, E. de Grave, P. M. A. De Bakker, R. E. Vandenberghe
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- Journal:
- Clays and Clay Minerals / Volume 43 / Issue 6 / December 1995
- Published online by Cambridge University Press:
- 28 February 2024, pp. 656-668
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Several samples of large- and small-particle magnetite (Fe3O4), as well as its thermal decomposition products formed at different temperatures and atmospheres, have been studied extensively by Mössbauer spectroscopy (MS), both with and without an applied field of 6T. Synthetic mixtures of magnetite and poorly- or well-crystallized maghemite have also been studied. Large-particle magnetite (MCD > 200 nm), when heated in air for 12 hours at T < 400°C, transforms to a mixture of well-crystallized hematite and magnetite, the latter one remaining stoichiometric, according to the relative area-ratios obtained from MS. Thermal treatment at 1300°C in a controlled O2 partial pressure, produced a mixture of stoichiometric and nonstoichiometric magnetite, but the latter component seems to be composed of particles with different degrees of nonstoichiometry. The Mössbauer spectra of the decomposition products at T < 200°C in air of small-particle magnetite (MCD ~ 80 nm) could be successfully interpreted as a mixture of magnetite and maghemite, rather than nonstoichiometric magnetite. This suggestion is further supported by the experiments with the synthetic mixtures. It is clearly demonstrated that is not possible, even by applying a strong external field, to separate the contribution of the A-site of magnetite from that of maghemite.
The Center Shift in Mössbauer Spectra of Maghemite and Aluminum Maghemites
- G. M. Da Costa, E. De Grave, L. H. Bowen, R. E. Vandenberghe, P. M. A. De Bakker
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- Clays and Clay Minerals / Volume 42 / Issue 5 / October 1994
- Published online by Cambridge University Press:
- 28 February 2024, pp. 628-633
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Synthetic, relatively well-crystallized aluminum-substituted maghemite samples, γ-(Aly·Fe1−y)2O3, with y = 0, 0.032, 0.058, 0.084, 0.106 and 0.151 have been studied by X-ray diffraction and zero-field Mössbauer spectroscopy in the range 8 K to 475 K, and also with an external field of 60 kOe at 4.2 K and 275 K. It was found that there are two different converging models for fitting the zero-field spectra of the maghemites with a superposition of two Lorentzian-shaped sextets, both resulting in inconsistent values for the hyperfine fields (Hhf) and/or the center shifts (δ) of the tetrahedral (A) and octahedral (B) ferric ions. From the applied-field measurements it is concluded that there is a constant difference of 0.12 ± 0.01 mm/s between δB and δA, regardless of the Al content. For the Al-free sample the center shifts are found as: δA = 0.370 mm/s and δB = 0.491 mm/s at 4.2 K and δA = 0.233 mm/s and δB = 0.357 mm/s at 275 K (relative to metallic iron), with an estimated error of 0.005 mm/s. Both δA and δB are observed to decrease with increasing Al concentration. The effective hyperfine fields for the non-substituted maghemite sample are: Heff,A = 575 kOe and Heff,B = 471 kOe at 4.2 K and Heff,A = 562 kOe and Heff,B = 449 kOe at 275 K, with an error of 1 kOe. The B-site hyperfine field remains approximately constant with Al substitution, while for the A site a slight decrease with increasing Al content was observed.
Quantification and Characterization of Maghemite in Soils Derived from Volcanic Rocks in Southern Brazil
- Antonio Carlos S. da Costa, Jerry M. Bigham, Fred E. Rhoton, Samuel J. Traina
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- Clays and Clay Minerals / Volume 47 / Issue 4 / August 1999
- Published online by Cambridge University Press:
- 28 February 2024, pp. 466-473
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Many soils developed from volcanic rocks in southern Brazil exhibit spontaneous magnetization caused by the presence of fine-grained maghemite (γ-Fe2O3), but few attempts were made to quantify or characterize this important soil component. To that end, clays were separated from freely drained soils derived from acid (≥63% SiO2), intermediate (54–62% SiO2), and basic (≤53% SiO2) igneous rocks produced by the Paraná flood volcanism. The sample set included soils with a wide range of pedogenic development on different landscape positions. The Fe oxide mineralogy of these samples was examined by using a combination of selective dissolution, magnetic susceptibility, and X-ray diffraction (XRD) techniques. Hematite and maghemite were the primary Fe oxides in mature soils (Oxisols, Ultisols, and Alfisols) developed from basic rocks; whereas goethite was dominant in all other soils, especially those formed from acid-intermediate rocks. The association of maghemite with basic rock materials suggests that it was primarily formed by oxidation of lithogenic magnetite. A strong, positive correlation (R2 = 0.89) was obtained between mass specific magnetic susceptibility (χ) of the clay fractions and maghemite contents estimated by XRD. Either method could be used for quantitative analyses, but χ was more sensitive than XRD at low maghemite concentrations (<2 wt. %). The clay-sized maghem-ites were superparamagnetic with an estimated value for the mass specific magnetic susceptibility (χlf) value of 91,000 × 10−8 m3 kg−1 and frequency dependent variations of 10–15%. The maghemites also had low unit cell constants, which, if attributed entirely to replacement of Fe by Al, would correlate with Al substitutions in the range of 5–16 mole %. Selective dissolution of the soil maghemites was achieved by treatment of Fe oxide concentrates with 1.8 M H2SO4 at 75°C for 2 h.
57Fe Mössbauer Effect Study of Al-Substituted Lepidocrocites
- E. De Grave, G. M. da Costa, L. H. Bowen, U. Schwertmann, R. E. Vandenberghe
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- Clays and Clay Minerals / Volume 44 / Issue 2 / April 1996
- Published online by Cambridge University Press:
- 28 February 2024, pp. 214-219
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Seven Al-containing lepidocrocite samples, γ-Fe1−xAlxOOH, prepared from FeCl2/Al(N03)3 solutions with initial Al/(Al + Fe) mole ratios Ci of 0.0025, 0.01, 0.025, 0.05, 0.075, 0.10 and 0.15 mol/mol, were examined by means of Mössbauer spectroscopy at room temperature (RT) and at various temperatures in the range of 8 to 80 K. The spectra at RT and 80°K consist of broadened quadrupole doublets and were analyzed in terms of a single doublet and of a model-independent quadrupole-splitting distribution, the latter yielding the best fit. The observed variations of the quadrupole-splitting parameters with increasing Ci are inconclusive as to whether the Al cations are substituting into the structure. The temperature at which the onset of magnetic ordering is reflected in the spectra, was measured by the thermoscan method with zero source velocity. A gradual shift from 50 K for Ci = 0.0025 mol/mol to 44 K for Ci = 0.10 mol/mol was observed for that temperature. As compared to earlier studies of Al-free γ-FeOOH samples with similar morphological characteristics, the fractional doublet area in the mixed sextet-doublet spectra at 35 K is significantly higher for the present lepidocrocites. This observation is ascribed to the substitution of Al cations into the lepidocrocite structure. A similar conclusion is inferred from the variation with Ci of the maximum-probability hyperfine field derived from the spectra recorded at 8 K and fitted with a model-independent hyperfine-field distribution. The magnetic results suggest that for the sample corresponding to Ci = 0.15 mol/mol, not all of the initially present Al has been incorporated into the structure.
Iron Oxides in a Soil Developed from Basalt
- A. T. Goulart, J. D. Fabris, M. F. de Jesus Filho, J. M. D. Coey, G. M. da Costa, E. de Grave
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- Clays and Clay Minerals / Volume 46 / Issue 4 / August 1998
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- 28 February 2024, pp. 369-378
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A dusky red Oxisol forming on a tholeiitic basalt is found to contain varying proportion of aluminous hematite (Hm) and titanoaluminous maghemite (Mh) in the different size fractions. Maghemite is the main iron oxide in the sand and silt fractions whereas Hm is dominant in the clay fraction, together with gibbsite (Gb), kaolinite (Ka), rutile (Rt) (and probably anatase, An) and Mh. Maghemite is also the major oxide mineral in the magnetic separates of soil fractions (sand, about 65% of the relative Mössbauer spectral area; silt, 60%). Hematite (sand, 30%; silt, 15%) and ilmenite (Im) (sand, 5%; silt, 16%) are also significantly present in the magnetic extract. Accessory minerals are Rt and An. No magnetite (Mt) was detected in any soil fraction. Sand- and silt-size Mh have similar nature (a 0= 0.8319 ± 0.0005 nm; about 8 mol% of Al substitution; saturation magnetization of 49 J T−1 kg−1), and certainly a common origin. Lattice parameters of clay-Mh are more difficult to deduce, as magnetic separation was ineffective in removing nonmagnetic phases. Al content in Hm varies from 14 mol% (clay and silt) to 20 mol% (sand). The proposed cation distribution on the spinel sites of the sand-size Mh is:
(◻ = vacancy, [ ] = tetrahedral sites and { } = octahedral sites), with a corresponding molar mass of 208.8 g mol−1. The predicted magnetization based on this formula is σ ≅ 68 J T−1 kg−1, assuming collinear spin arrangement. The large discrepancy with the experimentally determined magnetization is discussed.
Variable-Temperature Mössbauer Spectroscopy of Nano-Sized Maghemite and Al-Substituted Maghemites
- G. M. Da Costa, E. De Grave, L. H. Bowen, P. M. A. De Barker, R. E. Vandenberghe
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- Clays and Clay Minerals / Volume 43 / Issue 5 / October 1995
- Published online by Cambridge University Press:
- 28 February 2024, pp. 562-568
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Synthetic aluminum-substituted maghemite samples, γ-(Fe1-xAlx)2O3, have been prepared by thermal decomposition of Al-lepidocrocite (γ-Fe1-xAlxOOH), with × = 0, 0.04, 0.06, 0.14 and 0.18. The particles are needle-shaped and the mean crystallite diameter along the [311] crystallographic direction was found to be between 2.0 and 5.0 nm. Mössbauer spectra were collected at 6 K and from 80 K up to 475 K at steps of 25 K. In a wide range of temperatures the spectra of the non-substituted sample consist of a superposition of a broad sextet and a superparamagnetic doublet, whereas for the Al-maghemites this range is much smaller. From the temperature variation of the fractional doublet area two different parameters were defined: the temperature corresponding to a 50/50 doublet-sextet spectrum (T1/2), and the temperature below which the doublet ceases to exist (T0). These two parameters (T1/2 and T0) decrease from 390 K and 92 K (Al-free sample), to 118 K and 64 K (4 mole % Al) and to 100 K and 48 K (18 mole % Al), respectively. The average hyperfine fields at 6 K undergo a steep drop in going from the Al-free sample (Hhf = 506 kOe) to the sample with 4 mole % Al (Hhf = 498 kOe), but for higher substitutions the effect is much smaller. The A- and B-site quadrupole splittings, obtained from the data between 220 K and 475 K, were found as: ΔEQ,A = 0.86 ± 0.04 mm/s and ΔEQ,B = 0.65 ± 0.04 mm/s for the 4 mole % Al sample. The characteristic Mössbauer temperature, determined from the temperature dependence of the average isomer shift, was found to be in the range of 500–600 K.
Social connections and risk of incident mild cognitive impairment, dementia, and mortality in 13 longitudinal cohort studies of ageing
- Gowsaly Mahalingam, Suraj Samtani, Ben Chun Pan Lam, Darren M Lipnicki, Maria Fernanda Lima-Costa, Sergio Luis Blay, Erico Castro-Costa, Xiao Shifu, Maëlenn Guerchet, Pierre-Marie Preux, Antoine Gbessemehlan, Ingmar Skoog, Jenna Najar, Therese Rydberg Sterner, Nikolaos Scarmeas, Mary Yannakoulia, Themis Dardiotis, Ki-Woong Kim, Steffi Riedel-Heller, Susanne Röhr, Alexander Pabst, Suzana Shahar, Katya Numbers, Mary Ganguli, Tiffany F. Hughes, Ching-Chou H. Chang, Michael Crowe, Tze Pin Ng, Xinyi Gwee, Denise Qian Ling Chua, representatives from SHARED work packages, Joanna Rymaszewska, Karin Wolf-Ostermann, Anna-Karin Welmer, Jean Stafford, Myrra Vernooij-Dassen, Yun-Hee Jeon, Perminder S Sachdev, Henry Brodaty
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- Journal:
- International Psychogeriatrics / Volume 35 / Issue S1 / December 2023
- Published online by Cambridge University Press:
- 02 February 2024, pp. 16-17
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Background:
Good social connections are proposed to positively influence the course of cognitive decline by stimulating cognitive reserve and buffering harmful stress-related health effects. Prior meta-analytic research has uncovered links between social connections and the risk of poor health outcomes such as mild cognitive impairment, dementia, and mortality. These studies have primarily used aggregate data from North America and Europe with limited markers of social connections. Further research is required to explore these associations longitudinally across a wider range of social connection markers in a global setting.
Research Objective:We examined the associations between social connection structure, function, and quality and the risk of our primary outcomes (mild cognitive impairment, dementia, and mortality).
Method:Individual participant-level data were obtained from 13 longitudinal studies of ageing from across the globe. We conducted survival analysis using Cox regression models and combined estimates from each study using two-stage meta-analysis. We examined three social constructs: connection structure (living situation, relationship status, interactions with friends/family, community group engagement), function (social support, having a confidante) and quality (relationship satisfaction, loneliness) in relation to the risks of three primary outcomes (mild cognitive impairment, dementia, and mortality). In our partially adjusted models, we included age, sex, and education and in fully adjusted models used these variables as well as diabetes, hypertension, smoking, cardiovascular risk, and depression.
Preliminary results of the ongoing study:In our fully adjusted models we observed: a lower risk of mild cognitive impairment was associated with being married/in a relationship (vs. being single), weekly community group engagement (vs. no engagement), weekly family/friend interactions (vs. not interacting), and never feeling lonely (vs. often feeling lonely); a lower risk of dementia was associated with monthly/weekly family/friend interactions and having a confidante (vs. no confidante); a lower risk of mortality was associated with living with others (vs. living alone), yearly/monthly/weekly community group engagement, and having a confidante.
Conclusion:Good social connection structure, function, and quality are associated with reduced risk of incident MCI, dementia, and mortality. Our results provide actionable evidence that social connections are required for healthy ageing.
Somatic multicomorbidity and disability in patients with psychiatric disorders in comparison to the general population: a quasi-epidemiological investigation in 54,826 subjects from 40 countries (COMET-G study)
- Konstantinos N. Fountoulakis, Grigorios N. Karakatsoulis, Seri Abraham, Kristina Adorjan, Helal Uddin Ahmed, Renato D. Alarcón, Kiyomi Arai, Sani Salihu Auwal, Michael Berk, Sarah Bjedov, Julio Bobes, Teresa Bobes-Bascaran, Julie Bourgin-Duchesnay, Cristina Ana Bredicean, Laurynas Bukelskis, Akaki Burkadze, Indira Indiana Cabrera Abud, Ruby Castilla-Puentes, Marcelo Cetkovich, Hector Colon-Rivera, Ricardo Corral, Carla Cortez-Vergara, Piirika Crepin, Domenico De Berardis, Sergio Zamora Delgado, David De Lucena, Avinash De Sousa, Ramona Di Stefano, Seetal Dodd, Livia Priyanka Elek, Anna Elissa, Berta Erdelyi-Hamza, Gamze Erzin, Martin J. Etchevers, Peter Falkai, Adriana Farcas, Ilya Fedotov, Viktoriia Filatova, Nikolaos K. Fountoulakis, Iryna Frankova, Francesco Franza, Pedro Frias, Tatiana Galako, Cristian J. Garay, Leticia Garcia-Álvarez, Maria Paz García-Portilla, Xenia Gonda, Tomasz M. Gondek, Daniela Morera González, Hilary Gould, Paolo Grandinetti, Arturo Grau, Violeta Groudeva, Michal Hagin, Takayuki Harada, Tasdik M. Hasan, Nurul Azreen Hashim, Jan Hilbig, Sahadat Hossain, Rossitza Iakimova, Mona Ibrahim, Felicia Iftene, Yulia Ignatenko, Matias Irarrazaval, Zaliha Ismail, Jamila Ismayilova, Asaf Jakobs, Miro Jakovljević, Nenad Jakšić, Afzal Javed, Helin Yilmaz Kafali, Sagar Karia, Olga Kazakova, Doaa Khalifa, Olena Khaustova, Steve Koh, Svetlana Kopishinskaia, Korneliia Kosenko, Sotirios A. Koupidis, Illes Kovacs, Barbara Kulig, Alisha Lalljee, Justine Liewig, Abdul Majid, Evgeniia Malashonkova, Khamelia Malik, Najma Iqbal Malik, Gulay Mammadzada, Bilvesh Mandalia, Donatella Marazziti, Darko Marčinko, Stephanie Martinez, Eimantas Matiekus, Gabriela Mejia, Roha Saeed Memon, Xarah Elenne Meza Martínez, Dalia Mickevičiūtė, Roumen Milev, Muftau Mohammed, Alejandro Molina-López, Petr Morozov, Nuru Suleiman Muhammad, Filip Mustač, Mika S. Naor, Amira Nassieb, Alvydas Navickas, Tarek Okasha, Milena Pandova, Anca-Livia Panfil, Liliya Panteleeva, Ion Papava, Mikaella E. Patsali, Alexey Pavlichenko, Bojana Pejuskovic, Mariana Pinto Da Costa, Mikhail Popkov, Dina Popovic, Nor Jannah Nasution Raduan, Francisca Vargas Ramírez, Elmars Rancans, Salmi Razali, Federico Rebok, Anna Rewekant, Elena Ninoska Reyes Flores, María Teresa Rivera-Encinas, Pilar Saiz, Manuel Sánchez de Carmona, David Saucedo Martínez, Jo Anne Saw, Görkem Saygili, Patricia Schneidereit, Bhumika Shah, Tomohiro Shirasaka, Ketevan Silagadze, Satti Sitanggang, Oleg Skugarevsky, Anna Spikina, Sridevi Sira Mahalingappa, Maria Stoyanova, Anna Szczegielniak, Simona Claudia Tamasan, Giuseppe Tavormina, Maurilio Giuseppe Maria Tavormina, Pavlos N. Theodorakis, Mauricio Tohen, Eva Maria Tsapakis, Dina Tukhvatullina, Irfan Ullah, Ratnaraj Vaidya, Johann M. Vega-Dienstmaier, Jelena Vrublevska, Olivera Vukovic, Olga Vysotska, Natalia Widiasih, Anna Yashikhina, Panagiotis E. Prezerakos, Daria Smirnova
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- Journal:
- CNS Spectrums / Volume 29 / Issue 2 / April 2024
- Published online by Cambridge University Press:
- 25 January 2024, pp. 126-149
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Background
The prevalence of medical illnesses is high among patients with psychiatric disorders. The current study aimed to investigate multi-comorbidity in patients with psychiatric disorders in comparison to the general population. Secondary aims were to investigate factors associated with metabolic syndrome and treatment appropriateness of mental disorders.
MethodsThe sample included 54,826 subjects (64.73% females; 34.15% males; 1.11% nonbinary gender) from 40 countries (COMET-G study). The analysis was based on the registration of previous history that could serve as a fair approximation for the lifetime prevalence of various medical conditions.
ResultsAbout 24.5% reported a history of somatic and 26.14% of mental disorders. Mental disorders were by far the most prevalent group of medical conditions. Comorbidity of any somatic with any mental disorder was reported by 8.21%. One-third to almost two-thirds of somatic patients were also suffering from a mental disorder depending on the severity and multicomorbidity. Bipolar and psychotic patients and to a lesser extent depressives, manifested an earlier (15–20 years) manifestation of somatic multicomorbidity, severe disability, and probably earlier death. The overwhelming majority of patients with mental disorders were not receiving treatment or were being treated in a way that was not recommended. Antipsychotics and antidepressants were not related to the development of metabolic syndrome.
ConclusionsThe finding that one-third to almost two-thirds of somatic patients also suffered from a mental disorder strongly suggests that psychiatry is the field with the most trans-specialty and interdisciplinary value and application points to the importance of teaching psychiatry and mental health in medical schools and also to the need for more technocratically oriented training of psychiatric residents.
Selective logging intensity and time since logging drive tropical bird and dung beetle diversity: a case study from Amazonia
- Filipe M França, Wallace Beiroz, Christian B Andretti, Thiago VV Costa, Fernando Z Vaz-De-Mello, Juliana M Silveira, Julio Louzada
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- Environmental Conservation , First View
- Published online by Cambridge University Press:
- 02 January 2024, pp. 1-10
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Understanding how selective logging affects biodiversity is crucial to planning cost-effective conservation strategies in tropical forests, yet there is limited understanding of its impacts on fauna functional diversity in the tropical Americas. We assessed how selective logging intensification and time since logging influence multiple metrics of fauna functional integrity in the Brazilian Amazon by collecting bird and dung beetle data within 48 logging management units that had experienced varying exploitation intensities between 1.5–2.0 and 5.0–6.0 years before the faunal surveys. We investigated assemblage responses and used functional attributes to assess changes in functional diversity, specialization, originality and species rarity. Using point counts and pitfall traps, we collected 5081 records of 182 bird species and 7892 dung beetles from 45 species. Logging intensification led to significant declines in most dung beetle responses and bird body mass, whereas time since logging was a key driver of dung beetle and bird functional and taxonomic diversity. Our study presents novel empirical evidence of how logging intensification effects vary across taxa, ecological metrics and time since logging, which is key to informing forest conservation and further investigating environmental degradation impacts on tropical biodiversity.
Mineralogical, Chemical, and Physical Characterization of Synthetic Al-Substituted Maghemites (γ−Fe2−xAlxO3)
- Marcelo A. Batista, Antonio C. S. da Costa, Jerry M. Bigham, Henrique de Santana, Dimas A. M. Zaia, Ivan G. de Souza junior
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- Clays and Clay Minerals / Volume 58 / Issue 4 / August 2010
- Published online by Cambridge University Press:
- 01 January 2024, pp. 451-461
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Maghemite (γ-Fe2O3) is a ferrimagnetic Fe oxide commonly found in tropical and subtropical soils, especially in the topsoil where it is usually a product of burning. Isomorphic substitution (IS) of the Fe in maghemite by different metals (mainly Al3+) can modify its mineralogical and chemical attributes, and these modifications may be important to understanding the formation and properties of this mineral in soils and sediments. The objective of this work was to evaluate the crystallochemical alterations of synthetic, Al-substituted maghemites prepared by the precipitation of magnetites from alkaline aqueous media containing FeSO4·7H2O with increasing amounts of Al2(SO4)3·7H2O to obtain hypothetical Al3+ for Fe3+ substitutions ranging from 0.0 to 40.0 mol %. The Al-substituted magnetites were washed and dried, and then heated to 250ºC for 4 h to form yellowish red maghemites that were characterized by total chemical analysis, X-ray diffraction, specific surface area (SSA), mass-specific magnetic susceptibility, infrared spectroscopy, transmission electronic microscopy, and color. Increasing Al3+ substitution to an experimental maximum of 15.9 mol % decreased both the a0 dimension of the cubic unit cell (a0 = 0.8339 − 396.157 × 10−16 Al, r2 = 0.99) and the mean crystallite dimension (MCD = 76.4–3.15Al, r2 = 0.79) of the maghemites. With the decrease in MCD came a more yellowish color, an increase in SSA, and a decrease in crystallinity as measured through extraction of the samples with acid ammonium oxalate. The mass-specific magnetic susceptibility of the maghemites increased with Al3+ substitution up to 5.3 mol % and then decreased with further replacement of Fe by Al. Solid-phase aluminum in excess of 16 mol % substitution appeared to occur as a separate, poorly crystalline phase that was X-ray amorphous.
Difficulties during delivery, brain ventricle enlargement and cognitive impairment in first episode psychosis
- Ana Costas-Carrera, Norma Verdolini, Clemente Garcia-Rizo, Gisela Mezquida, Joost Janssen, Isabel Valli, Iluminada Corripio, Ana M. Sanchez-Torres, Miquel Bioque, Antonio Lobo, Ana Gonzalez-Pinto, Marta Rapado-Castro, Eduard Vieta, Helena De la Serna, Anna Mane, Alexandra Roldan, Nicolas Crossley, Rafael Penades, Manuel J. Cuesta, Mara Parellada, Miquel Bernardo, PEPs group
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- Journal:
- Psychological Medicine / Volume 54 / Issue 7 / May 2024
- Published online by Cambridge University Press:
- 28 November 2023, pp. 1339-1349
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Background
Patients with a first episode of psychosis (FEP) display clinical, cognitive, and structural brain abnormalities at illness onset. Ventricular enlargement has been identified in schizophrenia since the initial development of neuroimaging techniques. Obstetric abnormalities have been associated with an increased risk of developing psychosis but also with cognitive impairment and brain structure abnormalities. Difficulties during delivery are associated with a higher risk of birth asphyxia leading to brain structural abnormalities, such as ventriculomegaly, which has been related to cognitive disturbances.
MethodsWe examined differences in ventricular size between 142 FEP patients and 123 healthy control participants using magnetic resonance imaging. Obstetric complications were evaluated using the Lewis–Murray scale. We examined the impact of obstetric difficulties during delivery on ventricle size as well as the possible relationship between ventricle size and cognitive impairment in both groups.
ResultsFEP patients displayed significantly larger third ventricle size compared with healthy controls. Third ventricle enlargement was associated with diagnosis (higher volume in patients), with difficulties during delivery (higher volume in subjects with difficulties), and was highest in patients with difficulties during delivery. Verbal memory was significantly associated with third ventricle to brain ratio.
ConclusionsOur results suggest that difficulties during delivery might be significant contributors to the ventricular enlargement historically described in schizophrenia. Thus, obstetric complications may contribute to the development of psychosis through changes in brain architecture.
Pulmonary valve replacement in tetralogy of Fallot – who and how?
- Catarina M. Costa, Cristina Cruz, Teresa Pinho, Sofia Torres, João C. Silva, José A. Madureira, Elson Salgueiro, Jorge Casanova, Paulo Pinho, Filipe Macedo
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- Cardiology in the Young / Volume 34 / Issue 4 / April 2024
- Published online by Cambridge University Press:
- 03 November 2023, pp. 865-869
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Background and Aim:
Pulmonary regurgitation is the most common complication in repaired tetralogy of Fallot patients. Severe chronic pulmonary regurgitation can be tolerated for decades, but if not treated, it can progress to symptomatic, irreversible right ventricular dilatation and dysfunction. We investigated clinical associations with pulmonary valve replacement among patients with significative pulmonary regurgitation and how interventional developments can change their management.
Methods:All adult patients with repaired tetralogy of Fallot who were followed at an adult CHD Clinic at a single centre from 1980 to 2022 were included on their first outpatient visit. Follow-up was estimated from the time of correction surgery until one of the following events occurred first: pulmonary valve replacement, death, loss to follow-up or conclusion of the study.
Results:We included 221 patients (116 males) with a median age of 19 (18–25). At a median age of 33 (10) years old, 114 (51%) patients presented significant pulmonary regurgitation. Among patients with significant pulmonary regurgitation, pulmonary valve replacement was associated with male gender, older age at surgical repair, and longer QRS duration in adulthood. Pulmonary valve replacement was performed in 50 patients, including four transcatheter pulmonary valve implantations, at a median age of 34 (14) years.
Conclusion:Pulmonary regurgitation affects a large percentage of tetralogy of Fallot adult patients, requiring a long-term clinical and imaging follow-up. Sex, age at surgical repair and longer QRS are associated with the need of PVR among patients with significative pulmonary regurgitation. Clinical practice and current literature support TPVI as the future gold standard intervention.
Associations of free, bioavailable and total 25-hydroxyvitamin D with neonatal birth anthropometry and calcium homoeostasis in mother–child pairs in a sunny Mediterranean region
- Hana M. A. Fakhoury, Tarek Ziad Arabi, Hani Tamim, Rene F. Chun, William B. Grant, Martin Hewison, Fatme AlAnouti, Stefan Pilz, Cedric Annweiler, Georgios Tzimagiorgis, Costas Haitoglou, Spyridon N. Karras
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- Journal:
- British Journal of Nutrition / Volume 131 / Issue 5 / 14 March 2024
- Published online by Cambridge University Press:
- 26 October 2023, pp. 801-808
- Print publication:
- 14 March 2024
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Sufficient vitamin D status is crucial for successful pregnancy and fetal development. The assessment of 25-hydroxyvitamin D (25(OH)D) concentrations is commonly used to evaluate vitamin D status. Our objective was to examine the interrelated biodynamics of maternal and neonatal total, free and bioavailable 25(OH)D in maternal–neonatal dyads at birth and their associations with homeostasis and neonatal birth anthropometry. We analysed a cohort of seventy full-term mother–child pairs. We found positive associations between all neonatal measures of vitamin D status. Maternal forms exhibited a similar pattern of association, except for the bioavailable maternal form. In multivariate analysis, both total and free maternal 25(OH)D concentrations were correlated with all neonatal forms (neonatal total 25(OH)D: 1·29 (95 % CI, 1·12, 1·46) for maternal total 25(OH)D, 10·89 (8·16, 13·63) for maternal free 25(OH)D), (neonatal free 25(OH)D: 0·15 for maternal total 25(OH)D, 1·28 (95 % CI, 0·89, 1·68) for maternal free 25(OH)D) and (0·13 (95 % CI, 0·10, 0·16), 1·06 (95 % CI, 0·68, 1·43) for maternal free 25(OH)D), respectively, with the exclusion of the bioavailable maternal form. We observed no significant interactions within or between groups regarding maternal and neonatal vitamin D parameters and maternal calcium and parathyroid hormone concentrations, and neonatal birth anthropometry. Our study indicates that bioavailable maternal and neonatal 25(OH)D have no significant effects on vitamin D equilibrium, Ca homeostasis and neonatal anthropometry at birth. However, we observed an interaction between maternal and neonatal total and free 25(OH)D concentrations at the maternal–neonatal interface, with no associations observed with other calciotropic or anthropometric outcomes.
Water use efficiency and yield responses of Cenchrus purpureus genotypes under irrigation
- R. E. P. Ribeiro, A. C. L. Mello, M. V. Cunha, M. V. F. Santos, S. B. M. Costa, J. J. Coelho, R. O. Carvalho, V. J. Silva
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- The Journal of Agricultural Science / Volume 161 / Issue 4 / August 2023
- Published online by Cambridge University Press:
- 07 September 2023, pp. 572-580
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In tropical regions, water stress is one of the main causes of the reduction in forage productivity, and irrigation strategies can mitigate the problem, especially for highly productive species. The objective of this study was to evaluate the effects of irrigation, genotype and plant size on productive responses and water use efficiency (WUE) of elephant grass (Cenchrus purpureus [Schumach.] Morrone), in the rainy and dry season. The experimental design was randomized in blocks, arranged in split plots, the main plots were established based on the use of irrigation and the subplots were the tall-sized genotypes (IRI 381 and Elephant B) and dwarfs (Taiwan A-146 2.37 and Mott). The genotypes were evaluated for two years and harvested every 60 days. Water use efficiency, total forage accumulation per year and harvest, forage accumulation rate and forage density were evaluated. There was a significant difference between the genotypes in terms of total forage accumulated (P < 0.05). The most productive genotype was IRI 381, which showed the greatest total forage accumulation (42 168 kg of DM/ha in two years) in the irrigated plots. During the rainy seasons, IRI 381 stood out in terms of forage accumulated (24 667 kg of DM/ha). Irrigation favoured increases in forage accumulation around 60%, in both years of evaluation. Irrigation and plant size influenced the productivity and WUE of elephant grass harvested in 60-day intervals. Tall genotypes and Taiwan A-146 2.37 (dwarf size) stood out in most of the productive traits analysed, while Mott was highlighted by its forage density.
Night-time/daytime Protein S100B serum levels in paranoid schizophrenic patients
- E. Diaz-Mesa, A. Morera-Fumero, L. Torres-Tejera, A. Crisostomo-Siverio, P. Abreu-Gonzalez, R. Zuñiga-Costa, S. Yelmo-Cruz, R. Cejas-Mendez, C. Rodriguez-Jimenez, L. Fernandez-Lopez, M. Henry-Benitez
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- Journal:
- European Psychiatry / Volume 66 / Issue S1 / March 2023
- Published online by Cambridge University Press:
- 19 July 2023, pp. S445-S446
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Introduction
S100B is a calcium-binding astrocyte-specific cytokine, that is considered a biomarker of neurodegeneration; which may be involved in the imbalance of the inflammatory response observed in several brain disorders, including major depression and schizophrenia. Two meta-analyses have reported higher serum levels of S100B in patients with schizophrenia respect to healthy controls.
Different studies have described circadian and seasonal variations of biological variables, such as melatonin or cortisol. It has been reported that there is not circadian rhythm of S100B blood levels in healthy subjects. However, it is not known whether there are circadian oscillations in S100B blood concentrations in patients with schizophrenia.
ObjectivesThe aim of this study is to describe S100B serum levels in patients with schizophrenia and to analyse whether they follow a circadian rhythm.
MethodsOur sample consists in 47 patients in acute phase and stabilized status. Blood samples were collected at 12:00 and 00:00 hours by venipuncture. Serum levels of Protein S100B were measured three times: at admission, discharge and three months after discharge. Protein S100B was measured by means of ELISA (Enzyme-linked immunosorbent assay) techniques.
Results12:00 24:00 P ADMISSION 132,95±199,27 85,85±121,44 0,004 DISCHARGE 73,65±71,744 75,80±123,628 0,070 CONTROL 43,49±34,60 40,14±23,08 0,47 P global P Admission Vs. Discharge P Admission Vs. Control P Discharge Vs. Control 0,97 There is a significance difference between 12:00 and 24:00 at admission for the Protein S100B.However, these difference did not occur at discharge and at three months after discharge.It can be interpreted as there is a circadian rhythm of Protein S100B when the patient has got a psychotic outbreak and disappears at discharge and when is psychopathologically stable.
ConclusionsWith respect to our results we can hypothesize that schizophrenic patients in acute relapse present circadian S100B rhythm that is not present when the patients are clinically stable.Furthermore, the decrease of serum protein S100B levels at discharge is indicative of a reduction of the cerebral inflammation, thus it can be a biomarker of cerebral inflammation and this reduction can be the effect of the treatment. Finally, its circadianity could be a guide of this process and clinical improvement.
Disclosure of InterestNone Declared
The Fall of Icarus: Post-psychotic depression - Apropros a clinical case
- S. Jesus, A. R. Costa, G. Simões, M. Almeida, A. Tarelho, P. Garrido
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- Journal:
- European Psychiatry / Volume 66 / Issue S1 / March 2023
- Published online by Cambridge University Press:
- 19 July 2023, pp. S843-S844
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Introduction
Depressive symptoms occur in different phases of psychosis, including prodromal, acute and post-psychotic. Post-psychotic depression (PPD) is a phenomenon that presents as a diagnostic and therapeutic challenge. Having been ascribed various descriptions in the past, PPD has been used in a broad manner to describe depressive symptoms that appear in patients with history of psychosis. PPD unveils itself as a separate nosological entity, differing from the adverse effects typically associated with antipsychotics, the negative symptoms of psychosis, and other psychiatric disorders that present with both psychotic and depressive symptoms (e.g. bipolar disorder, schizoaffective disorder, or psychotic depression).
ObjectivesThe authors present a case of a 64 year-old man hospitalized due to inaugural psychosis with persecutory and grandiose delusions as well as auditory hallucinatory activity, who began to develop a depressive clinical picture whilst under treatment. A brief discussion on post-psychotic depression, from its clinical presentation to its treatment and implications in prognosis is also presented.
MethodsA brief non-systematized literature review using the Pubmed platform as well as presentation of a clinical case.
ResultsDepressive complaints are a common complication of psychotic episodes, with the literature estimating that approximately a quarter of psychotic patients present with PPD. Although typically described in association with schizophrenia, recent literature describes PPD occurring alongside other psychotic presentations, including first-episode psychosis. A division between affect and psychosis has been attempted in terms of psychiatric classification, however, the blurred lines between the two continue to contribute to difficulties in differential diagnosis. This becomes a challenge when distinguishing between extrapyramidal symptoms associated with antipsychotics, negative symptoms (i.e apathy, abulia and alogia) and psychiatric disorders with affective-psychotic overlap. Having only recently been considered a distinct clinical entity in psychiatric classification systems, research on its etiology, course, treatment and prognosis are scarce. In regards to the previously described patient, a depressive disorder whilst in treatment for psychosis was identified, and through early recognition of the symptoms treatment with an antidepressant was initiated with favourable response.
ConclusionsPPD is a relatively common phenomenon which is gaining more attention in recent literature. As classifications have begun to consider PPD as a distinct clinical entity, as well as unifying defining criteria, further studies can be developed so as to clarify aspects which remain to be defined. The clinician should be aware of this entity as well as the potentially confounding symptom presentations, so as to provide adequate early treatment thus contributing to improved patient outcomes.
Disclosure of InterestNone Declared
Brief reactive psychosis….again! - Clinical case report
- A. R. Costa, S. Jesus, M. Almeida, C. Vicente
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- Journal:
- European Psychiatry / Volume 66 / Issue S1 / March 2023
- Published online by Cambridge University Press:
- 19 July 2023, p. S1045
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Introduction
Brief psychotic disorder according to the DSM-5 is a condition of sudden onset lasting less than 1 month followed by complete remission with possible future relapses, characterized by the development of psychotic conditions. The duration of the illness is a differentiating factor from other disorders such as schizophreniform psychosis or schizophrenia. When there is a stressful event at the origin of the psychotic symptomatology, it is also called brief reactive psychosis. The pathophysiology of BPD is not known, especially given the extremely low incidence of the disorder. This condition most often affects people in their 20s, 30s, and 40s, and its higher prevalence among patients with personality or mood disorders may suggest an underlying biological or psychological susceptibility that may have some genetic influence.
ObjectivesTo describe the main diagnostic considerations, clinical manifestations, treatment, prognosis and prevention of brief reactive psychosis through the description of a clinical case that developed two episodes of brief reactive psychosis in a period of 1 year and to emphasize the importance of maintaining treatment for a period of suitable time.
MethodsCase report and literature search with the terms: brief reactive psychosis, psychosis, neuroleptic, stressor event.
ResultsWe describe the clinical case of a 29-year-old woman, born in S. Tomé and Príncipe, previously healthy, with no personal or family history of mental illness, who had her first brief reactive episode after coming to Portugal. With the introduction of the 2nd generation antipsychotic, paliperidone, there was a substantial improvement in the condition, however, with the development of side effects having subsequently abandoned the treatment. About 1 year after starting work in Portugal, she develops a new event, a new psychotic episode, with characteristics of a brief psychotic disorder.
ConclusionsIt is extremely important to alert patients to the possible side effects of drugs, as well as those who experience a brief psychotic episode, which are the risk factors and the need to comply with treatment in order to avoid a new relapse.
Disclosure of InterestNone Declared
Ethics in mental health research
- M. Pinto da Costa
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- Journal:
- European Psychiatry / Volume 66 / Issue S1 / March 2023
- Published online by Cambridge University Press:
- 19 July 2023, pp. S55-S56
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Abstract
The boundaries between innovative clinical practices and research-related experimentation can be difficult to distinguish. Whilst mental health research has increased remarkably over recent decades, ethics is required to maintain and improve the standards of mental health research. Ethics and science can be seen as opposing forces with different aims championed by different people. However, ethics should not be a barrier to scientific advancement, but rather as the way that mental health research can be conducted with broader societal support, with the expectation of bringing wider benefit to people with mental illness. Scientific advancements may also lead to novel ethical problems and raise questions in relation to oversight responsibilities. Mental health research faces several unique ethical challenges. This presentation will provide an overview of the ethical issues linked with mental health research.
Disclosure of InterestNone Declared
Healthy mental higher education students’: Presentation of a project
- A. Torres, J. Costa, P. Carvalho, M. Loureiro
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- Journal:
- European Psychiatry / Volume 66 / Issue S1 / March 2023
- Published online by Cambridge University Press:
- 19 July 2023, pp. S985-S986
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Introduction
The prevalence of mental disorders in Higher Education Students (HES) is high and has shown a worrying growth. However, only a small percentage of HES in need of psychological support request it, due to the stigma related to mental illness, requesting informal help from friends and family. Training and increasing Mental Health Literacy (MHL) have been stated as appropriate strategies to reduce stigma and increase the demand for professional psychological support. However, with the increase in the demand for help, the difficulty of providing an adequate response from psychological support of HE services also increases. Therefore, procedures that develop socio-emotional skills in the HES and strategies that enhance the responsiveness of these services are necessary.
ObjectivesTaking in consideration the literature review in this field, we develop a project to improve the mental health of HES. The project objectives’: a) the reduction of stigma related to mental disorders through the promotion of MHL in the academic community; b) the promotion of mental health and socio-emotional skills of HES; c) increasing detection and active search for professional mental health support, and d) the implementation of psychological intervention based on a stepped care model that provides an adequate response to most of the students’ mental health needs, according to individual needs.
MethodsThe project proposes to perform the following methods: a) training in mental health open to the academic community, which will aim to train volunteers to be Gatekeepers, in order to promote awareness, detection and referral of students in need of professional psychological support; b) implementation of a Student Observatory, with tracking of psychopathological symptoms, supported on the Web; c) implementation of a psychological intervention program based on a stepped care model, which will include the following progressive phases by severity: 1) digital self-help manual; 2) web-based self-help groups; 3) psychological intervention groups supported by the Web; 4) face-to-face intervention groups and 5) individual psychological intervention.
Students will be assessed before and after each step of care, with the following psychological instruments: Mental Health Inventory (MHI); Patient Health Questionnaire (PHQ-9) and Generalized Anxiety Disorder (GAD-7).
ResultsThe implementation of the presented methods expect to achieve improvements on HES’ mental health, namely improvement of MHI, reduction of PHQ-9 and GAD-7 after each step of the psychological care.
ConclusionsThe project presented encloses evidence-based interventions, with inspiration on psychoeducation and cognitive behavioral approaches, and it is expected to contribute to the improvement of mental health of HES. The results will be collected and disseminated. We encourage other researcher and clinicians to perform studies about the mental health of HES.
Disclosure of InterestNone Declared
The Green-Eyed Monster: A Brief Exploration of the Jealousy Spectrum
- S. Jesus, A. R. Costa, M. Almeida, P. Garrido
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- Journal:
- European Psychiatry / Volume 66 / Issue S1 / March 2023
- Published online by Cambridge University Press:
- 19 July 2023, p. S1002
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Introduction
A feeling as ancient as humankind, having been documented in the Bible, represented by mythological figures and appearing as a recurrent theme in art and literature, jealousy is a complex emotion that is non-discriminatory and often associated with negative feelings ranging from insecurity, suspicion, rage, fear to humiliation. Commonly associated with romantic relationships, it typically arises when one perceives a threat, either real or imagined, from a third party in regards to possession or perceived security. Jealousy, like other aspects of the human experience, varies in its expression and intensity, ranging from an adaptive response to a potentially dangerous psychopathological symptom.
ObjectivesThe authors aim to describe jealousy and discuss the spectrum on which it appears, ranging from an adaptive response to a psychopathological manifestation.
MethodsA brief non-structured literature review was carried out with recourse to various databases such as Pubmed as well as complimentary literary sources when deemed pertinent.
ResultsDescribed as a defensive reaction that is expressed as a cognitive, emotional and behavioural response to a perceived threat, jealousy has been discussed in various arenas of thought ranging from evolutionary psychology to philosophy to psychiatry to representation in the arts. It is a difficult term to define as it is a feeling expressed through diverse emotions and behaviours originating from various contexts as well as varying in its intensity. The literature demonstrates that jealousy can exist as an adaptive response, with evolutionary explanations, to a psychopathological expression either as obsessive jealousy or morbid jealousy, also known as Othello’s Syndrome. Each carries its own particularities in terms of expression, clinical significance and intervention. The more often described delusional jealousy, is characterized by the presence of strong, false beliefs that the partner is unfaithful, whereas obsessive jealousy, less commonly described, presents with unpleasant, ego-dystonic and irrational jealous ruminations that the partner could be unfaithful. These thoughts are often accompanied by compulsive verification of the partners’ behaviour. Treatment interventions in these cases are varied and present implications in prognosis.
ConclusionsJealousy is a complex emotional state and has been described as part of the universal human experience, with research indicating its existence across various cultures. The expression of this emotional experience as well as its potential manifestation types should be taken into consideration by the mental health practitioner when carrying out an evaluation, as treatment interventions and prognosis may vary depending on the presentation.
Disclosure of InterestNone Declared