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.
Neuroimaging studies have documented brain structural changes in schizophrenia at different stages of the illness, including clinical high-risk (cHR), genetic high-risk (gHR), first-episode schizophrenia (FES), and chronic schizophrenia (ChS). There is growing awareness that neuropathological processes associated with a disease fail to map to a specific brain region but do map to a specific brain network. We sought to investigate brain structural damage networks across different stages of schizophrenia.
Methods
We initially identified gray matter alterations in 523 cHR, 855 gHR, 2162 FES, and 2640 ChS individuals relative to 6963 healthy controls. By applying novel functional connectivity network mapping to large-scale discovery and validation resting-state functional magnetic resonance imaging datasets, we mapped these affected brain locations to four specific networks.
Results
Brain structural damage networks of cHR and gHR had limited and non-overlapping spatial distributions, with the former mainly involving the frontoparietal network and the latter principally implicating the subcortical network, indicative of distinct neuropathological mechanisms underlying cHR and gHR. By contrast, brain structural damage networks of FES and ChS manifested as similar patterns of widespread brain areas predominantly involving the somatomotor, ventral attention, and subcortical networks, suggesting an emergence of more prominent brain structural abnormalities with illness onset that have trait-like stability over time.
Conclusions
Our findings may not only provide a refined picture of schizophrenia neuropathology from a network perspective, but also potentially contribute to more targeted and effective intervention strategies for individuals at different schizophrenia stages.
Following the 2020 cardiopulmonary resuscitation (CPR) guidelines, this study compared participant’s fatigue with the quality of manual chest compressions performed in the head-up CPR (HUP-CPR) and supine CPR (SUP-CPR) positions for two minutes on a manikin.
Methods:
Both HUP-CPR and SUP-CPR were performed in a randomized order determined by a lottery-style draw. Manual chest compressions were then performed continuously on a realistic manikin for two minutes in each position, with a 30-minute break between each condition. Data were collected on heart rate, blood pressure, and Borg rating of perceived exertion (RPE) scale scores from the participants before and after the compressions.
Results:
Mean chest compression depth (MCCD), mean chest compression rate (MCCR), accurate chest compression depth ratio (ACCDR), and correct hand position ratio were significantly lower in the HUP group than that in the SUP group. However, there were no significant differences in accurate chest compression rate ratio (ACCRR), correct recoil ratio, or mean arterial pressure (MAP) before and after chest compressions between the two groups. Changes in heart rate and RPE scores were greater in the HUP group.
Conclusion:
High-quality manual chest compressions can still be performed when the CPR manikin is placed in the HUP position. However, the quality of chest compressions in the HUP position was poorer than those in the SUP position, and rescuer fatigue was increased.
Despite mounting evidence linking neurological diseases with climate change, the link between autism spectrum disorder (ASD) and global warming has yet to be explored.
Aims
To examine the relationship between the incidence of ASD and global warming from 1990 to 2019 and estimate the trajectory of ASD incidence from 2020 to 2100 globally.
Method
We extracted meteorological data from TerraClimate between 1990 and 2019. To estimate the association between global ASD incidence and temperature variation, we adopted a two-stage analysis strategy using a generalised additive regression model. Additionally, we projected future ASD incidence under four representative shared socioeconomic pathways (SSPs: 126, 245, 370 and 585) by bootstrapping.
Results
Between 1990 and 2019, the global mean incidence of ASD in children under 5 years old was 96.9 per 100 000. The incidence was higher in males (147.5) than in females (46.3). A 1.0 °C increase in the temperature variation was associated with a 3.0% increased risk of ASD incidence. The association was stronger in boys and children living in a low/low-middle sociodemographic index region, as well as in low-latitude areas. According to the SSP585 scenario, by 2100, the children living in regions between 10 and 20° latitude, particularly in Africa, will experience a 68.6% increase in ASD incidence if the association remains. However, the SSP126 scenario is expected to mitigate this increase, with a less than 10% increase in incidence across all latitudes.
Conclusions
Our study highlights the association between climate change and ASD incidence worldwide. Prospective studies are warranted to confirm the association.
Hepatitis E virus infection is a major cause of acute hepatitis, typically self-limiting but occasionally leading to liver failure. Understanding disease progression factors could inform prevention strategies. This study aimed to analyse the characteristics of a large cohort of hospitalised hepatitis E patients in Tianjin, China, and explore factors influencing their progression to liver failure. A total of 1279 hospitalised patients with hepatitis E were included in this cross-sectional study in Tianjin, China. Student's t-test and the Mann–Whitney U-test were used for comparisons. Multiple logistic regression analysis was used to explore the association. Among these 1279 patients, 107 (8.4%) developed liver failure. Patients with diabetes mellitus (DM) (95% confidence interval [CI] 1.150–2.887, p = 0.011), liver cirrhosis (95% [CI] 2.229–7.224, p < 0.001), and hepatitis B (95% [CI] 1.159–4.512, p = 0.017) were more likely to progress to liver failure. Hepatitis E patients with comorbid DM, liver cirrhosis, or hepatitis B virus co-infection have higher risks of developing liver failure. Hepatitis E vaccination may be recommended for these vulnerable patients to curb disease severity.
Spatiotemporal mode-locking creates great opportunity for pulse energy scaling and nonlinear optics research in fiber. Until now, spatiotemporal mode-locking has only been realized in normal-dispersion dissipative soliton and similariton fiber lasers. In this paper, we demonstrated the first experimental realization of a spatiotemporally mode-locked soliton laser in mid-infrared fluoride fiber with anomalous dispersion. The mode-locked fluoride fiber oscillator directly generated a record pulse energy of 16.1 nJ and peak power of 74.6 kW at 2.8 μm wavelength. This work extends the spatiotemporal mode-locking to soliton fiber lasers and should have a wide interest for the laser community.
Parametric interaction allows both forward and backward energy transfers among the three interacting waves. The back-conversion effect is usually detrimental when unidirectional energy transfer is desired. In this theoretical work, we manifest that the back-conversion effect underpins the direct generation of the picosecond pulse train without the need for a laser resonator. The research scenario is an optical parametric amplification (OPA) that consists of a second-order nonlinear medium, a quasi-continuous pump laser and a sinusoidal amplitude-modulated seed signal. The back-conversion of OPA can transfer the modulation peaks (valleys) of the incident signal into output valleys (peaks), which inherently induces spectral sidebands. The generation of each sideband is naturally accompanied with a phase shift of ±π. In the regime of full-back-conversion, the amount and amplitude of the sidebands reach the maximum simultaneously, and their phase constitutes an arithmetic sequence, leading to the production of a picosecond pulse train. The generated picosecond pulse train can have an ultrahigh repetition rate of 40 GHz or higher, which may facilitate ultrafast applications with ultrahigh speed.
In strong-field physics experiments with ultraintense lasers, a single-shot cross-correlator (SSCC) is essential for fast optimization of the pulse contrast and meaningful comparison with theory for each pulse shot. To simultaneously characterize an ultrashort pulse and its long pedestal, the SSCC device must have both a high resolution and a large temporal window. However, the resolution and window in all kinds of single-shot measurement contradict each other in principle. Here we propose and demonstrate a novel SSCC device with two separate measurement channels: channel-1 for the large-window pedestal measurement has a moderate resolution but a large window, while channel-2 for the ultrashort pulse measurement has a small window but a high resolution; this allows the accurate characterization of the pulse contrast in a single shot. A two-channel SSCC device with a 200-fs resolution and 114-ps window has been developed and tested for its application in ultraintense lasers at 800 nm.
Hyperhomocysteinaemia (HHcy) is associated with all-cause mortality in some disease states. However, the correlation between HHcy and the risk of mortality in the general population has rarely been researched. We aimed to evaluate the association between HHcy and all-cause and cause-specific mortality among adults in the USA. This study analysed data from the National Health and Nutrition Examination Survey database (1999–2002 survey cycle). A multivariable Cox regression model was built to evaluate the correlation between HHcy and all-cause and cause-specific mortality. Smooth curve fitting was used to analyse their dose-dependent relationship. A total of 8442 adults aged 18–70 years were included in this study. After a median follow-up period of 14·7 years, 1007 (11·9 %) deaths occurred including 197 CVD-related deaths, 255 cancer-related deaths and fifty-eight respiratory disease deaths. The participants with HHcy had a 93 % increased risk of all-cause mortality (hazard ratio (HR) 1·93; 95 % CI (1·48, 2·51)), 160 % increased risk of CVD mortality (HR 2·60; 95 % CI (1·52, 4·45)) and 82 % increased risk of cancer mortality (HR 1·82; 95 % CI (1·03, 3·21)) compared with those without HHcy. For unmeasured confounding, E-value analysis proved to be robust. In conclusion, HHcy was associated with high risk of all-cause and cause-specific (CVD, cancer) mortality among adults aged below 70 years.
Optical parametric chirped-pulse amplification is inevitably subject to high-order spatial chirp, particularly under the condition of saturated amplification and a Gaussian pump; this corresponds to an irreversible spatiotemporal distortion and consequently degrades the maximum attainable focused intensity. In this paper, we reveal that such spatial chirp distortion can be significantly mitigated in quasi-parametric chirped-pulse amplification (QPCPA) with idler absorption. Simulation results show that the quality of focused intensity in saturated QPCPA is nearly ideal, with a spatiotemporal Strehl ratio higher than 0.98. As the seed bandwidth increases, the idler absorption spectrum may not be uniform, but the Strehl ratio in QPCPA can be still high enough due to stronger idler absorption.
A new characterization of tabularity in tense logic is established, namely, a tense logic L is tabular if and only if $\mathsf {tab}_n^T\in L$ for some $n\geq 1$. Two characterization theorems for the Post-completeness in tabular tense logics are given. Furthermore, a characterization of the Post-completeness in the lattice of all tense logics is established. Post numbers of some tense logics are shown.
Many protected areas conduct awareness-raising activities to increase local knowledge and support conservation programmes, but the effectiveness of such activities is rarely assessed. Public awareness-raising has been carried out since the early 2000s around Bawangling National Nature Reserve, Hainan, China, to improve conservation knowledge about the Critically Endangered Hainan gibbon Nomascus hainanus, one of the rarest mammals. We conducted 207 interviews in 25 villages around Bawangling National Nature Reserve to evaluate the outcome of previous conservation education, through comparison of variation in local respondent knowledge and attitudes, and specific enquiries about sources of knowledge acquisition. Likelihood of accurate responses to most of our questions regarding the species was positively correlated with local exposure to gibbon-themed billboards and murals, and respondents exhibited greater knowledge about several key conservation indices for gibbons compared to their knowledge about sympatrically occurring rhesus macaques Macaca mulatta. Many respondents specifically reported they knew about local existence, population size, conservation status, and threats to gibbons from past awareness-raising activities, with village education sessions and billboards widely identified as key sources of information. However, other known awareness-raising approaches have had little detectable effect on shaping local conservation awareness. Although educational activities have improved awareness about gibbons and their conservation requirements in relative terms, overall levels of knowledge remain low in many important areas and ongoing improvement of local awareness is still needed, in particular around poorly-understood topics such as gibbon conservation status, rarity and threats, and for socio-demographic groups possessing less conservation knowledge.
The theory of plate tectonics suggests that deformation occurs mainly along plate boundaries; however, compression can result in the formation of orogens and basins within intracontinental settings. During these two tectonic processes, the sedimentation and environmental changes occur in response to marginal and intracontinental deformation. Early Jurassic – Early Cretaceous deformation and basin formation along the Qinling orogenic belt and the northwestern Sichuan Basin in central–SW China are ideal for investigating a reactivated tectonic belt and basin formation. We studied the Lower Jurassic – Lower Cretaceous sedimentary sequences and structures along the northwestern margin of the Sichuan Basin, and obtained detrital zircon U–Pb ages for these rocks. The structures show that deformation migrated SE-wards and S-wards into the Sichuan Basin along the Longmen Shan, Micang Shan and Daba Shan tectonic belts during middle–late Mesozoic time. The Lower Jurassic oligomictic conglomerates have a smaller grain size and thicken towards the south, indicating protracted transport from a northern source. The conglomerates deposited near-source record post-orogenic south-vergent thrusting during the Late Triassic – Early Jurassic epochs. The Lower Cretaceous conglomerates and sandstones have multiple sources, which indicate that they were rapidly deposited near their source, synchronous with thrusting that occurred in response to coeval SE-wards and S-wards thrusting in the Longmen Shan and Daba Shan tectonic belts during the Late Jurassic – Early Cretaceous epochs. Detrital zircon grains from the Lower Jurassic – Lower Cretaceous sedimentary rocks yielded age peaks of 2600–2200, 1850–1600, 850–700, 540–400, 250–180 and 180–140 Ma. A comparison of these ages with those of surrounding exposed rocks indicates that the sediments in the northwestern Sichuan Basin were supplied from the Qinling orogenic belt, the northwestern Yangtze Block, the south margin of the North China Block and the Songpan–Garzê Terrane. The youngest peaks of detrital zircon U–Pb ages at 207 and 159 Ma constrain the two stages of intracontinental shortening and highlight the link between intracontinental deformation and sedimentation.
The gut microbiota is directly influenced by dietary components, and it plays critical roles in chronic diseases. Excessive consumption of trans-fatty acids (TFA) is associated with obesity induced by alterations in gut microbiota, but the links between obesity and gut microbiota remain unclear. Therefore, studies examining the impact of TFA on intestinal microflora are essential. In our study, we performed 16S ribosomal RNA gene sequencing on faecal samples from Sprague–Dawley rats fed a basal diet (control (CON) group), high-fat (HF) diet (diet-induced obesity (DIO) group) or TFA diets (1 % TFA group and 8 % TFA group) for 8 weeks to investigate the effects of TFA/HF diets on obesity and gut microbiota composition. We found that the TFA/HF diets significantly induced obesity and changes in blood and brain physiological parameters of the rats. The relative abundance of the phyla Firmicutes and Bacteroidetes was inversely altered in the three test groups compared with the CON group. Proteobacteria increased slightly in the DIO, 1 % TFA and 8 % TFA groups. The genus Bacteroides increased in the DIO and 1 % TFA groups, but Muribaculaceae decreased in all experimental groups compared with the CON group. Moreover, significant differences were observed among clusters of orthologous group functional categories of the four dietary groups. Our observations suggested that the TFA/HF diets induced obesity and dysfunction of gut microbiota. Gut dysbiosis might mediate the obesity effects of TFA/HF diets.
To investigate the association of folic acid (FA) supplementation with birth weight, the risk of small for gestational age (SGA) and low birth weight (LBW) in singleton and twin pregnancy.
Design:
A population-based cross-sectional survey.
Setting:
Twenty counties and ten districts in Shaanxi Province of northwestern China, 2013.
Participants:
28 174 pregnant women with their infants, covering 27 818 single live births and 356 twin live births.
Results:
The prevalence of FA supplementation in singletons and twins was 63·9 and 66·3 %. The mean birth weight was 3267 (sd 459·1) g, 2525 (sd 534·0) g and 2494 (sd 539·5) g; the prevalence of SGA was 14·3, 51·4 and 53·4 %; the prevalence of LBW was 3·4, 42·4 and 46·6 % among singleton, twin A and twin B, respectively. Compared with non-users, women with FA supplementation were (β 17·3, 95 % CI 6·1, 28·4; β 166·3, 95 % CI 69·1, 263·5) associated with increased birth weight, lower risk of SGA (OR 0·85, 95 % CI 0·80, 0·92; OR 0·45, 95 % CI 0·30, 0·68) and LBW (OR 0·82, 95 % CI 0·71, 0·95; OR 0·50, 95 % CI 0·33, 0·75) in singletons and twins, and more prominent effects in twins. Moreover, there were significant interactions between FA supplementation and plurality on birth weight, SGA and LBW.
Conclusions:
The present study suggests the association of periconceptional 0·4 mg/d FA supplementation with increased birth weight and reduced risk of SGA and LBW in both singletons and twins, and this association may be more prominent in twins.
Clay often has severe detrimental impacts on cement-based materials. Therefore, it is necessary to investigate the mechanism causing the deterioration to improve the service life of cement-based materials. Based on accurate dimensional analysis, a mechanism that influences clay is proposed: the intercalation of the side chains of superplasticizer molecules in the interlayer space of the clay. To lessen this harmful effect, a new clay-resistant admixture (CRA) possessing cationic groups of small molecular size was synthesized through a novel dimensional design. The length and width of the side chains of this superplasticizer molecule were 9.50–17.50 and 0.25–0.40 nm, respectively, with a radius of ~3.74 nm in solvent, which is larger than the interlayer spacing of montmorillonite (i.e. 1.09–2.14 nm). The longitudinal and latitudinal lengths of the CRA molecule were 0.468 and 9.456 nm, respectively, ensuring intercalation in the interlayer of montmorillonite. The increase in interlayer spacing of the clay was 0.364 nm following addition of polycarboxylate superplasticizer (PCE) plus CRA and 0.632 nm following addition of PCE, which suggests that the CRA plays the role of a ‘sacrificial agent’ that is preferentially intercalated into the interlayer space of clay to further prevent the side chains of the superplasticizer molecules from entering the interlayer. The aim of this study was to propose a suitable means of synthesizing a new CRA to address the impact of clay through dimensional design and mechanism analysis, which contributes to the theoretical study and technological improvement of cement-based materials.
United Nations (UN) personnel address a diverse range of political, social, and cultural crises throughout the world. Compared with other occupations routinely exposed to traumatic stress, there remains a paucity of research on mental health disorders and access to mental healthcare in this population. To fill this gap, personnel from UN agencies were surveyed for mental health disorders and mental healthcare utilization.
Methods
UN personnel (N = 17 363) from 11 UN entities completed online measures of generalized anxiety disorder (GAD), major depressive disorder (MDD), posttraumatic stress disorder (PTSD), trauma exposure, mental healthcare usage, and socio-demographic information.
Results
Exposure to one or more traumatic events was reported by 36.2% of survey responders. Additionally, 17.9% screened positive for GAD, 22.8% for MDD, and 19.9% for PTSD. Employing multivariable logistic regressions, low job satisfaction, younger age (<35 years of age), greater length of employment, and trauma exposure on or off-duty was significantly associated with all the three disorders. Among individuals screening positive for a mental health disorder, 2.05% sought mental health treatment within and 10.01% outside the UN in the past year.
Conclusions
UN personnel appear to be at high risk for trauma exposure and screening positive for a mental health disorder, yet a small percentage screening positive for mental health disorders sought treatment. Despite the mental health gaps observed in this study, additional research is needed, as these data reflect a large sample of convenience and it cannot be determined if the findings are representative of the UN.
Several observational studies have investigated the association of insomnia with psychiatric disorders. Such studies yielded mixed results, and whether these associations are causal remains unclear. Thus, we aimed to identify the causal relationships between insomnia and five major psychiatric disorders.
Methods:
The analysis was implemented with six genome-wide association studies; one for insomnia and five for psychiatric disorders (attention-deficit/hyperactivity disorder, autism spectrum disorder, major depressive disorder, schizophrenia, and bipolar disorder). A heterogeneity in dependent instrument (HEIDI) approach was used to remove the pleiotropic instruments, Mendelian randomization (MR)-Egger regression was adopted to test the validity of the screened instruments, and bidirectional generalized summary data-based MR was performed to estimate the causal relationships between insomnia and these major psychiatric disorders.
Results:
We observed significant causal effects of insomnia on the risk of autism spectrum disorder and bipolar disorder, with odds ratios of 1.739 (95% confidence interval: 1.217–2.486, p = 0.002) and 1.786 (95% confidence interval: 1.396–2.285, p = 4.02 × 10−6), respectively. There was no convincing evidence of reverse causality for insomnia with these two disorders (p = 0.945 and 0.546, respectively). When insomnia was considered as either the exposure or outcome variable, causal estimates for the remaining three psychiatric disorders were not significant.
Conclusions:
Our results suggest a causal role of insomnia in autism spectrum disorder and bipolar disorder. Future disease models should include insomnia as a factor for these two disorders to develop effective interventions. More detailed mechanism studies may also be inspired by this causal inference.
High-power femtosecond lasers beyond $5~\unicode[STIX]{x03BC}\text{m}$ are attractive for strong-field physics with mid-infrared (IR) fields but are difficult to scale up. In optical parametric chirped-pulse amplification (OPCPA) at mid-IR wavelengths, a nonlinear crystal is vital, and its transmittance, dispersion, nonlinear coefficient and size determine the achievable power and wavelength. OPCPA beyond $5~\unicode[STIX]{x03BC}\text{m}$ routinely relies on semiconductor crystals because common oxide crystals are not transparent in this spectral range. However, the small size and low damage threshold of semiconductor crystals fundamentally limit the peak power to gigawatts. In this paper, we design a terawatt-class OPCPA system at $5.2~\unicode[STIX]{x03BC}\text{m}$ based on a new kind of oxide crystal of $\text{La}_{3}\text{Ga}_{5.5}\text{Nb}_{0.5}\text{O}_{14}$ (LGN). The extended transparent range, high damage threshold, superior phase-matching characteristics and large size of LGN enable the generation of 0.13 TW seven-cycle pulses at $5.2~\unicode[STIX]{x03BC}\text{m}$. This design fully relies on the state-of-the-art OPCPA technology of an octave-spanning ultrafast Ti:sapphire laser and a thin-disk Yb:YAG laser, offering the performance characteristics of high power, a high repetition rate and a stable carrier–envelope phase.
In the 2015 review paper ‘Petawatt Class Lasers Worldwide’ a comprehensive overview of the current status of high-power facilities of ${>}200~\text{TW}$ was presented. This was largely based on facility specifications, with some description of their uses, for instance in fundamental ultra-high-intensity interactions, secondary source generation, and inertial confinement fusion (ICF). With the 2018 Nobel Prize in Physics being awarded to Professors Donna Strickland and Gerard Mourou for the development of the technique of chirped pulse amplification (CPA), which made these lasers possible, we celebrate by providing a comprehensive update of the current status of ultra-high-power lasers and demonstrate how the technology has developed. We are now in the era of multi-petawatt facilities coming online, with 100 PW lasers being proposed and even under construction. In addition to this there is a pull towards development of industrial and multi-disciplinary applications, which demands much higher repetition rates, delivering high-average powers with higher efficiencies and the use of alternative wavelengths: mid-IR facilities. So apart from a comprehensive update of the current global status, we want to look at what technologies are to be deployed to get to these new regimes, and some of the critical issues facing their development.
Polypropylene plastic (PP) was chosen as additives for the preparation of activated carbon (AC), considering that PP promotes pore formation during the preparation of AC. When the addition ratio of PP was 20%, AC having a maximum specific surface area of 1916.1 m2/g was prepared. Fourier transform–infrared spectroscopy (FT-IR) analysis exhibited the types of functional groups on the surface of AC, such as–OH, C=O, C–C, and –CH. The SEM analysis revealed the formation of disordered pores over the AC. Furthermore, iodine value of the AC is 1460 mg/g. Additionally, adsorption test revealed the AC is suitable for adsorbing methylene blue (MB). The adsorption equilibrium data of MB onto AC were most suitable for Redlich–Peterson model. The maximum adsorption capacity of the single layer was 476.88 mg/g, indicating that AC has high adsorption capacity. The kinetic data fitted well with the pseudo-second-order model.