We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure no-reply@cambridge.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Pebrine disease, caused by Nosema bombycis (Nb) infection in silkworms, is a severe and long-standing disease that threatens sericulture. As parasitic pathogens, a complex relationship exists between microsporidia and their hosts at the mitochondrial level. Previous studies have found that the translocator protein (TSPO) is involved in various biological functions, such as membrane potential regulation, mitochondrial autophagy, immune responses, calcium ion channel regulation, and cell apoptosis. In the present study, we found that TSPO expression in silkworms (BmTSPO) was upregulated following Nb infection, leading to an increase in cytoplasmic calcium, adenosine triphosphate, and reactive oxygen species levels. Knockdown and overexpression of BmTSPO resulted in the promotion and inhibition of Nb proliferation, respectively. We also demonstrated that the overexpression of BmTSPO promotes host cell apoptosis and significantly increases the expression of genes involved in the immune deficiency and Janus kinase-signal transducer and the activator of the transcription pathways. These findings suggest that BmTSPO activates the innate immune signalling pathway in silkworms to regulate Nb proliferation. Targeting TSPO represents a promising approach for the development of new treatments for microsporidian infections.
Genes involved in melanin production directly impact insect pigmentation and can affect diverse physiology and behaviours. The role these genes have on sex behaviour, however, is unclear. In the present study, the crucial melanin pigment gene black was functionally characterised in an urban pest, the German cockroach, Blattella germanica. RNAi knockdown of B. germanica black (Bgblack) had no effect on survival, but did result in black pigmentation of the thoraxes, abdomens, heads, wings, legs, antennae, and cerci due to cuticular accumulation of melanin. Sex-specific variation in the pigmentation pattern was apparent, with females exhibiting darker coloration on the abdomen and thorax than males. Bgblack knockdown also resulted in wing deformation and negatively impacted the contact sex pheromone-based courtship behaviour of males. This study provides evidence for black function in multiple aspects of B. germanica biology and opens new avenues of exploration for novel pest control strategies.
Suicide rates in adolescents with major depressive disorder (MDD) change with age and gender. Early adulthood is an important transitional stage between late adolescence and adulthood, in which an individual's mind gradually matures. However, there are fewer studies on prevalence and variables linked to the suicide attempts of young adults with MDD.
Aims
To explore gender differences in the prevalence and risk factors associated with suicide attempts in young adults with first-episode drug-naive MDD.
Method
The Hamilton Rating Scale for Depression (HRSD), Hamilton Rating Scale for Anxiety (HRSA) and Positive Subscale of the Positive and Negative Syndrome Scale (PANSS) were used to assess depression, anxiety and psychotic symptoms respectively and various biochemical indicators were assessed.
Results
Among 293 young adults with first-episode drug-naive MDD, the prevalence of suicide attempts was 15.45% (19/123) for males and 14.12% (24/170) for females. Males with suicide attempts had higher levels of thyroid-stimulating hormone (TSH) and higher PANSS Positive Subscale scores, whereas females with suicide attempts had higher TSH, serum total cholesterol, fasting blood glucose and diastolic blood pressure levels and higher scores on the HRSD, HRSA, PANSS Positive Subscale (all Bonferroni corrected P < 0.05). In males, PANSS Positive Subscale score (B = 0.17, P = 0.03, OR = 1.19, 95% CI 1.02–1.38) was a risk factor for suicide attempts.
Conclusions
There were significant gender differences in the risk factors for suicide attempts in young adults with first-episode drug-naive MDD.
As frontline workers, pharmacists often face significant work stress, especially in psychiatric settings. A multicenter cross-sectional design was conducted in 41 psychiatric hospitals. The Depression, Anxiety and Stress Scale–21 (DASS-21) was used to measure the mental health of 636 pharmacists. We also collected demographic data and work-related variables. The prevalence of depression, anxiety and stress was 20.60%, 22.96% and 8.96%, respectively. Multivariate logistic regression showed that several common factors were associated with depression, anxiety and stress, including professional identity (odds ratio [OR] = 0.132, 0.381 and 0.352) and verbal violence (OR = 2.068, 2.615 and 2.490). Those who were satisfied with their job were less likely to develop depression (OR = 0.234) or anxiety (OR = 0.328). We found specific factors associated with mental health. Older age (OR = 1.038) and perceived negative impact (OR = 2.398) of COVID-19 on medical work were associated with anxiety, and those with frontline experience with COVID-19 patients (OR = 2.306) were more likely to experience stress. More than one-fifth of pharmacists in psychiatric hospitals experienced symptoms of depression or anxiety during the pandemic, highlighting the need for policy change to improve workplace conditions and psychological well-being for this professional group.
To explore the relationship between dietary antioxidant quality score (DAQS) and Cd exposure both alone and in combination with osteoporosis and bone mineral density (BMD) among postmenopausal women. In total, 4920 postmenopausal women from the National Health and Nutrition Examination Survey were included in this cross-sectional study. Weighted univariate and multivariate logistic regression analyses to assess the association between DAQS and Cd exposure with femur neck BMD, total femur BMD, osteoporosis among postmenopausal women, respectively, and the coexistence effect of DAQS and Cd exposure. Four hundred and ninety-nine had osteoporosis. DAQS (OR = 0·86, 95 % CI 0·77, 0·97) and high DAQS (OR = 0·60, 95 % CI 0·36, 0·99) were found to be associated with decreased odds of osteoporosis, while Cd exposure (OR = 1·34, 95 % CI 1·04, 1·72) and high Cd exposure (OR = 1·45, 95 % CI 1·02, 2·06) were related to increased odds of osteoporosis. A positive correlation was observed between high DAQS and both total femur BMD and femur neck BMD. Conversely, Cd exposure was found to be negatively correlated with total femur BMD and femur neck BMD. Additionally, taking low-Cd and high-quality DAQS group as reference, the joint effect of Cd exposure and DAQS showed greater increased odds of osteoporosis and decreased total femur BMD and femur neck BMD as Cd level and DAQS combinations worsened. There may be an interaction between Cd exposure and DAQS for femur neck BMD, total femur BMD, and osteoporosis in postmenopausal women.
We report VLBI monitoring observations of the 22 GHz H2O masers toward the Mira variable BX Cam. Data from 37 epochs spanning ∼3 stellar pulsation periods were obtained between May 2018 and June 2021 with a time interval of 3–4 weeks. In particular, the VERA dual-beam system was used to measure the kinematics and parallaxes of the H2O maser features. The obtained parallax, 1.79±0.08 mas, is consistent with Gaia EDR3 and previous VLBI measurements. The position of the central star was estimated relied on Gaia EDR3 data and the center position of the 43 GHz SiO maser ring imaged with KVN. Analysis of the 3D maser kinematics revealed an expanding circumstellar envelope with a velocity of 13±4 km s−1 and significant spatial and velocity asymmetries. The H2O maser animation achieved by our dense monitoring program manifests the propagation of shock waves in the circumstellar envelope of BX Cam.
Apolipoprotein E (APOE) E4 is the main genetic risk factor for Alzheimer’s disease (AD). Due to the consistent association, there is interest as to whether E4 influences the risk of other neurodegenerative diseases. Further, there is a constant search for other genetic biomarkers contributing to these phenotypes, such as microtubule-associated protein tau (MAPT) haplotypes. Here, participants from the Ontario Neurodegenerative Disease Research Initiative were genotyped to investigate whether the APOE E4 allele or MAPT H1 haplotype are associated with five neurodegenerative diseases: (1) AD and mild cognitive impairment (MCI), (2) amyotrophic lateral sclerosis, (3) frontotemporal dementia (FTD), (4) Parkinson’s disease, and (5) vascular cognitive impairment.
Methods:
Genotypes were defined for their respective APOE allele and MAPT haplotype calls for each participant, and logistic regression analyses were performed to identify the associations with the presentations of neurodegenerative diseases.
Results:
Our work confirmed the association of the E4 allele with a dose-dependent increased presentation of AD, and an association between the E4 allele alone and MCI; however, the other four diseases were not associated with E4. Further, the APOE E2 allele was associated with decreased presentation of both AD and MCI. No associations were identified between MAPT haplotype and the neurodegenerative disease cohorts; but following subtyping of the FTD cohort, the H1 haplotype was significantly associated with progressive supranuclear palsy.
Conclusion:
This is the first study to concurrently analyze the association of APOE isoforms and MAPT haplotypes with five neurodegenerative diseases using consistent enrollment criteria and broad phenotypic analysis.
Jurassic sandstones in the Xiongcun porphyry copper–gold district, southern Lhasa subterrane, Tibet, China were analysed for petrography, major oxides and trace elements, as well as detrital zircon U–Pb and Hf isotopes, to infer their depositional age, provenance, intensity of source-rock palaeo-weathering and depositional tectonic setting. This new information provides important evidence to constrain the tectonic evolution of the southern Lhasa subterrane during the Late Triassic – Jurassic period. The sandstones are exposed in the lower and upper sections of the Xiongcun Formation. Their average modal abundance (Q21F11L68) classifies them as lithic arenite, which is also supported by geochemical studies. The high chemical index of alteration values (77.19–85.36, mean 79.96) and chemical index of weathering values (86.19–95.59, mean 89.98) of the sandstones imply moderate to intensive weathering of the source rock. Discrimination diagrams based on modal abundance, geochemistry and certain elemental ratios indicate that felsic and intermediate igneous rocks constitute the source rocks, probably with a magmatic arc provenance. The detrital zircon ages (161–243 Ma) and εHf(t) values (+10.5 to +16.2) further constrain the sandstone provenance as subduction-related Triassic–Jurassic felsic and intermediate igneous rocks from the southern Lhasa subterrane. A tectonic discrimination method based on geochemical data of the sandstones, as well as detrital zircon ages from sandstones, reveals that the sandstones were most likely deposited in an oceanic island-arc setting. These results support the hypothesis that the tectonic background of the southern Lhasa subterrane was an oceanic island-arc setting, rather than a continental island-arc setting, during the Late Triassic – Jurassic period.
Herbicide-resistant (R biotype) and -sensitive (S biotype) individuals were identified from the same population, and seed was increased for each biotype for three generations. We conducted laboratory experiments to determine the effects of temperature, light, salt stress, osmotic stress, pH, and burial depth on the germination and emergence of resistant and sensitive biotypes of Japanese foxtail. The results revealed that there was no difference in the final germination rate between the two biotypes under different temperature conditions, but time to obtain 50% germination or emergence (tE50) and mean germination time of the R biotype were higher than that of the S biotype at 10 C and 15/10 C 12-h day/night regime. In dark conditions, the final germination rate of the S biotype was higher and lower than that of the R biotype at 10 and 25 C, respectively. The overall germination rate of the R biotype was lower than that in the S biotype, and extended germination time was required in extreme conditions, such as 250 mM NaCl and −0.4 MPa osmotic potential. The change in environmental pH had no effect on the germination of the two biotypes. Emergence of the R biotype was lower than the S biotype when seed was buried at least 8 cm deep in an organic matter substrate. This study demonstrated the pleiotropic effects of a resistance allele on seed germination and emergence under different environmental conditions. Deep tillage could be used to reduce the growth and spread of resistant Japanese foxtail individuals.
miR-124, a brain-specific microRNA, was originally considered as a key regulator in neuronal differentiation and the development of the nervous system. Here we showed that miR-124 expression was suppressed in patients with epilepsy and rats after drug induced-seizures. Intrahippocampal administration of a miR-124 duplex led to alleviated seizure severity and prolonged onset latency in two rat models (pentylenetetrazole- and pilocarpine-induced seizures), while miR-124 inhibitor led to shortened onset latency in pilocarpine-induced seizure rat models. Moreover, the result of local field potentials (LFPs) records further demonstrated miR-124 may have anti-epilepsy function. Inhibition of neuronal firing by miR-124 was associated with the suppression of mEPSC, AMPAR- and NMDAR-mediated currents, which were accompanied by decreased surface expression of NMDAR. In addition, miR-124 injection resulted in decreased activity and expression of cAMP-response element-binding protein1 (CREB1). a key regulator in epileptogenesis. A dual-luciferase reporter assay was used to confirm that miR-124 targeted directly the 3′UTR of CREB1 gene and repressed the CREB1 expression in HEK293T cells. Immunoprecipitation studies confirmed that the CREB1 antibody effectively precipitated CREB1 and NMDAR1 but not GLUR1 from rat brain hippocampus. These results revealed a previously unknown function of miR-124 in neuronal excitability and provided a new insight into molecular mechanisms underlying epilepsy.
Tolerance of transgressions can influence the social cognitive and moral development of children and adolescents. Given the prevalent tolerance for bribery throughout the developing world and in China, the present research identified bribery as a serious transgression and investigated the various effects of moral evaluations and descriptive norms on transgression tolerance with increasing age. Thus, two studies examined these effects among primary, middle, and high school students (N = 972, 10-, 13-, and 16-year-olds). In Study 1, students’ transgression tolerance was negatively influenced by moral evaluations, and no age trend emerged. However, students reported more transgression tolerance with age owing to their increasing understanding of descriptive norms. In Study 2, the descriptive norms were manipulated: individuals in the high descriptive norm condition showed greater transgression tolerance than those in the low descriptive norm condition. An increasing tolerance of transgressions was observed only for those in the high descriptive norm condition. The effect of descriptive norms was found to contribute to the transgression tolerance trend.
Gd2TixZr2−xO7 (x = 0 to 2) pyrochlore was irradiated by 30 MeV C60 clusters, which provide an extremely high ionizing energy density. High-resolution transmission electron microscopy revealed a complex ion-track structure in Gd2Ti2O7 and Gd2TiZrO7, consisting of an amorphous core and a shell of a disordered, defect-fluorite structure. As compared with the irradiation by 1.5 GeV U ions with the highest energy loss, the track structure is consistent with tracks created by monoatomic swift heavy ions, but the diameters (with the entire diameter of 17 nm for Gd2Ti2O7 and 15 nm for Gd2TiZrO7) are significantly larger due to the much smaller velocity and higher energy density of the C60 ions. Ion tracks created by monoatomic ions are challenging to describe by HRTEM, as the boundary between disordered fluorite and pyrochlore matrix is less distinct. However, the C60 irradiation shows a clearly resolved ion track with completely crystalline, disordered, defect-fluorite structure around an amorphous core. Based on the distinct boundaries of the track morphology, inelastic thermal-spike calculations were used to describe the track size and extract critical energy densities for the interpretation of the complex core–shell morphologies for the different pyrochlore compositions.
Recent efforts to characterize the nanoscale structural and chemical modifications induced by energetic ion irradiation in nuclear materials have greatly benefited from the application of synchrotron-based x-ray diffraction (XRD) and x-ray absorption spectroscopy (XAS) techniques. Key to the study of actinide-bearing materials has been the use of small sample volumes, which are particularly advantageous, as the small quantities minimize the level of radiation exposure at the ion-beam and synchrotron user facility. This approach utilizes energetic heavy ions (energy range: 100 MeV–3 GeV) that pass completely through the sample thickness and deposit an almost constant energy per unit length along their trajectory. High energy x-rays (25–65 keV) from intense synchrotron light sources are then used in transmission geometry to analyze ion-induced structural and chemical modifications throughout the ion tracks. We describe in detail the experimental approach for utilizing synchrotron radiation (SR) to study the radiation response of a range of nuclear materials (e.g., ThO2 and Gd2TixZr2−xO7). Also addressed is the use of high-pressure techniques, such as the heatable diamond anvil cell, as a new means to expose irradiated materials to well-controlled high-temperature (up to 1000 °C) and/or high-pressure (up to 50 GPa) conditions. This is particularly useful for characterizing the annealing kinetics of irradiation-induced material modifications.
A synthetic cubic pyrochlore, Gd2Ti2O7 (Fd3̅m) irradiated with swift heavy ions is compared with a compositionally-related composition La2Ti2O7 (P21), which has a monoclinic, layered, perovskite-type structure. Irradiation experiments were performed at the GSI Helmholtz Center with 181Ta ions and 129Xe ions at specific energies of 11MeV/amu. At these energies the ions pass entirely through the sample thickness of ∼ 40 μm. Angle-dispersive synchrotron powder x-ray diffraction (XRD) measurements were completed and an increasing ion-induced amorphization with increasing ion fluence was for both phases. The ion track cross-sections for the radiation-induced crystalline-to-amorphous transformation, as determined from the evolution of the integrated peak intensities as a function of fluence, reveal that La2Ti2O7 (track diameter, d ∼ 7.2 nm with 181Ta and 5.1 nm with 129Xe) is more susceptible to amorphization than Gd2Ti2O7 (d ∼ 6.2 nm with 181Ta and 4.6 nm with 129Xe). The radiation response of the two titanate compounds can be understood in the context of their different structures and cation ionic radius ratios rA/rB, where the susceptibility of radiation of titanate pyrochlores is proportionate with this radius ratio. The higher electronic linear energy loss of the 181Ta ions as compared with 129Xe ions leads to a consistent increase of volume amorphized per ion in both materials, which manifests as a larger track diameter.
A chemical decomposition and related phase transformation have been observed in 2.2 GeV 197Au irradiated SnO2 nanopowder. X-ray diffraction (XRD), Raman spectroscopy, and transmission electron microscopy (TEM) were used to characterize the transformation from tetragonal SnO2 (P42/mnm) into tetragonal SnO (P4/nmm). Rietveld refinement of the XRD data determined the structures and proportion of these phases up to a fluence of 2.4×1013 ions/cm2. The initially intense diffraction maxima corresponding to SnO2 gradually decrease in intensity with an increase in fluence. At a fluence of approximately 3.9×1012 ions/cm2, diffraction maxima corresponding to SnO become clearly evident and increase in intensity as fluence increases. Both Raman and TEM analyses confirm the transformation from tetragonal SnO2 to SnO. The XRD refinement results are consistent with a multiple-impact model of transformation, confirmed by TEM as no single tracks were observed. Previous swift heavy ion irradiations of SnO2 have led only to changes in grain size, degrees of crystallinity, and the formation of “holes”. The inconsistency in results is discussed in depth. The proposed mechanism for the currently observed transformation is the interrelation of defect accumulation and thermal-spike mechanisms. The formation of SnO, apparent O loss from the transformation regions, and associated Sn reduction are discussed in terms of thermodynamic, kinetic, and thermal-spike model considerations.
The dynamics of track development due to the passage of relativistic heavy ions through solids is a long-standing issue relevant to nuclear materials, age dating of minerals, space exploration, and nanoscale fabrication of novel devices. We have integrated experimental and simulation approaches to investigate nanoscale phase transitions under the extreme conditions created within single tracks of relativistic ions in Gd2O3(TiO2)x and Gd2Zr2–xTixO7. Track size and internal structure depend on energy density deposition, irradiation temperature, and material composition. Based on the inelastic thermal spike model, molecular dynamics simulations follow the time evolution of individual tracks and reveal the phase transition pathways to the concentric track structures observed experimentally. Individual ion tracks have nanoscale core-shell structures that provide a unique record of the phase transition pathways under extreme conditions.
The isometric, pyrochlore structure type, A2B2O7, exhibits a wide variety of properties that find application in a large number of different technologies, from electrolytes in solid oxide fuel cells to actinide-bearing compositions that can be used as nuclear waste forms or inert matrix nuclear fuels. Swift xenon ions (1.43 GeV) have been used to systematically modify different compositions in the Gd2Zr2-xTixO7 binary at the nanoscale by radiation-induced phase transitions that include the crystalline-to-amorphous and order-disorder structural transformations. Synchrotron x-ray diffraction, Raman spectroscopy, and transmission electron microscopy provide a complete and consistent description of structural changes induced by the swift heavy ions and demonstrate that the response of pyrochlore depends strongly on chemical composition. The high and dense electronic energy deposition primarily results in amorphization of Ti-rich pyrochlore; whereas the formation of the fully disordered, defect-fluorite structure is the dominant process for Zr-rich pyrochlore.
Coffinite (USiO4, I41/amd, Z=4) is the major alteration phase of uraninite, UO2+x, under reducing conditions in natural uranium deposits. Thus, it is important to understand the radiation response of coffinite because it is an expected alteration product of the UO2 in spent nuclear fuel. In the present study, we conducted in-situ transmission electron microscopy (TEM) investigation of synthetic coffinite under 1 MeV-Kr2+ ion beam irradiation. The radiation-induced crystalline-to-amorphous transformation was observed in the synthetic nanocrystalline USiO4, with a critical dose of ∼ 0.27 displacements per atoms (dpa) for which full amorphization occurred at room temperature. The critical dose increases as rising irradiation temperature, and above the critical temperature (Tc), ∼ 608 K, coffinite cannot be amorphized. These results are compared with previous studies on the isostructural zircon (ZrSiO4, Tc=1000K) and thorite (ThSiO4, Tc>1100K), which indicates that synthetic coffinite is more stable to ion beam irradiation at elevated temperature.
Aliphatic tetrafluoro-poly-p-xylylene (PA-f), has been evaluated as an interlayer dielectric and its properties reported. It has a lower dielectric constant (2.38) and higher thermal stability (480°C) than Parylene-n. The as-deposited films are of very low crystallinity. The crystallinity increases as the film is annealed. Thermo-Gravimetric Analysis has shown that these films loose weight at temperatures > 480°C. A shrinkage in the films of about 10% was observed when annealed in vacuum at a temperature of 425°C. The as-deposited films were measured to have low dielectric constant of 2.38 and a volume resistivity of 1.3×1016 ohm-cm. The refractive index in the optical wavelengths was measured to be 1.3 for as-deposited samples which increased with anneal temperatures. The stress levels observed are also lower (19 MPa) than PA-n (40 MPa) after annealing. Diffusion of Cu into PA-f is comparable with Cu diffusion in PMDA-ODA polyimide. Scanning Electron Microscopy of film cross-section shows microstructure change above temperatures of 350°C.