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The TanDEM-X DEM is a valuable data source for estimating glacier mass balance. However, the accuracy of TanDEM-X elevation over glaciers can be affected by microwave penetration and phase decorrelation. To investigate the bias of TanDEM-X DEMs of glaciers on the Tibetan Plateau, these DEMs were subtracted from SPOT-6 DEMs obtained around the same time at two study sites. The average bias over the studied glacier areas in West Kunlun (175.0 km2) was 2.106 ± 0.012 m in April 2014, and it was 1.523 ± 0.011 m in Geladandong (228.8 km2) in October 2013. By combining backscatter coefficients and interferometric coherence maps, we found surface decorrelation and baseline decorrelation can cause obvious bias in addition to microwave penetration. If the optical/laser data and winter TanDEM-X data were used as new and historic elevation sources for mass-balance measurements over an arbitrary observation period of 10 years, the glacier mass loss rates in West Kunlun and Geladandong would be potentially underestimated by 0.218 ± 0.016 and 0.158 ± 0.011 m w.e. a−1, respectively. The impact is therefore significant, and users should carefully treat the bias of TanDEM-X DEMs when retrieving a geodetic glacier mass balance.
Accurate measurements of food volume and density are often required as ‘gold standards’ for calibration of image-based dietary assessment and food database development. Currently, there is no specialised laboratory instrument for these measurements. We present the design of a new volume of density (VD) meter to bridge this technological gap.
Our design consists of a turntable, a load sensor, a set of cameras and lights installed on an arc-shaped stationary support, and a microcomputer. It acquires an array of food images, reconstructs a 3D volumetric model, weighs the food and calculates both food volume and density, all in an automatic process controlled by the microcomputer. To adapt to the complex shapes of foods, a new food surface model, derived from the electric field of charged particles, is developed for 3D point cloud reconstruction of either convex or concave food surfaces.
We conducted two experiments to evaluate the VD meter. The first experiment utilised computer-synthesised 3D objects with prescribed convex and concave surfaces of known volumes to investigate different food surface types. The second experiment was based on actual foods with different shapes, colours and textures. Our results indicated that, for synthesised objects, the measurement error of the electric field-based method was <1 %, significantly lower compared with traditional methods. For real-world foods, the measurement error depended on the types of food volumes (detailed discussion included). The largest error was approximately 5 %.
The VD meter provides a new electronic instrument to support advanced research in nutrition science.
Social anxiety disorder (SAD) is a prevalent mental disorder diagnosed in childhood and adolescence. Theories regarding brain development and SAD suggest a close link between neurodevelopmental dysfunction at the adolescent juncture and SAD, but direct evidence is rare. This study aims to examine brain structural abnormalities in adolescents with SAD.
High-resolution T1-weighted images were obtained from 31 adolescents with SAD (15–17 years) and 42 matching healthy controls (HC). We evaluated symptom severity with the Social Anxiety Scale for Children (SASC) and the Screen for Child Anxiety Related Emotional Disorders (SCARED). We used voxel-based morphometry analysis to detect regional gray matter volume abnormalities and structural co-variance analysis to investigate inter-regional coordination patterns.
We found significantly higher gray matter volume in the orbitofrontal cortex (OFC) and the insula in adolescents with SAD compared to HC. We also observed significant co-variance of the gray matter volume between the OFC and amygdala, and the OFC and insula in HC, but these co-variance relationships diminished in SAD.
These findings provide the first evidence that the brain structural deficits in adolescents with SAD are not only in the core regions of the fronto-limbic system, but also represented by the diminished coordination in the development of these regions. The delayed and unsynchronized development pattern of the fronto-limbic system supports SAD as an adolescent-sensitive developmental mental disorder.
In the laser plasma interaction of quantum electrodynamics (QED)-dominated regime, γ-rays are generated due to synchrotron radiation from high-energy electrons traveling in a strong background electromagnetic field. With the aid of 2D particle-in-cell code including QED physics, we investigate the preplasma effect on the γ-ray generation during the interaction between an ultraintense laser pulse and solid targets. We found that with the increasing preplasma scale length, the γ-ray emission is enhanced significantly and finally reaches a steady state. Meanwhile, the γ-ray beam becomes collimated. This shows that, in some cases, the preplasmas will be piled up acting as a plasma mirror in the underdense preplasma region, where the γ-rays are produced by the collision between the forward electrons and the reflected laser fields from the piled plasma. The piled plasma plays the same role as the usual reflection mirror made from a solid target. Thus, a single solid target with proper scale length preplasma can serve as a manufactural and robust γ-ray source.
Maternal supraphysiological estradiol (E2) environment during pregnancy leads to adverse perinatal outcomes. However, the influence of oocyte exposure to high E2 levels on perinatal outcomes remains unknown. Thus, a retrospective cohort study was conducted to explore the effect of high E2 level induced by controlled ovarian stimulation (COH) on further outcomes after frozen embryo transfer (FET). The study included all FET cycles (n = 10,581) between 2014 and 2017. All cycles were categorized into three groups according to the E2 level on the day of the human Chorionic Gonadotropin trigger. Odds ratios (ORs) and their confidence intervals (CIs) were calculated to evaluate the association between E2 level during COH and pregnancy outcomes and subsequent neonatal outcomes. From our findings, higher E2 level was associated with lower percentage of chemical pregnancy, clinical pregnancy, ongoing pregnancy, and live birth as well as increased frequency of early miscarriage. Preterm births were more common among singletons in women with higher E2 level during COH (aOR1 = 1.93, 95% CI: 1.22–3.06; aOR2 = 2.05, 95% CI: 1.33–3.06). Incidence of small for gestational age (SGA) was more common in both singletons (aOR1 = 2.01, 95% CI: 1.30–3.11; aOR2 = 2.51, 95% CI: 1.69–3.74) and multiples (aOR1 = 1.58, 95% CI: 1.03–2.45; aOR2 = 1.99, 95% CI: 1.05–3.84) among women with relatively higher E2 level. No association was found between high E2 level during COH and the percentage of macrosomia or large for gestational age. In summary, oocyte exposure to high E2 level during COH should be brought to our attention, since the pregnancy rate decreasing and the risk of preterm birth and SGA increasing following FET.
Currently, there is no uniform and standard disaster medicine course for students in medical school.
To design a disaster medicine course model based on knowledge structure, teaching and evaluation methods according to experts’ advice and interest of undergraduates majoring in clinical medicine.
The first and second level catalog defined as chapters and sections for the disaster medicine curriculum were drafted based on literature and summary of fragmentary experience. The teaching syllabus with methods of teaching and evaluation was initially outlined. The expert consultation form and student questionnaire were designed and validated. Experts in disaster medicine in China were consulted and students in our medical school were investigated. Delphi Methods was used and the chapters and sections were adjusted and weighed according to experts’ advice through the Analytic Hierarchy Process. The teaching and evaluation methods for each knowledge module were obtained based on suggestions from experts and students.
A total of 31 experts were consulted. 320 students were inquired. By two rounds of consultation with Kendall coordination coefficient W value 0.207, chi-square value 128.781(p=0.01), consensus about the knowledge structure for the curriculum were achieved, which consisted of 6 chapters (as Introduction to disaster medicine, incident command, medical knowledge and skills in disaster, public health, ethics in disaster, information management, with the weights of 0.1486, 0.1999, 0.4209, 0.0785, 0.0748, 0.0774 respectively)and 25 sections. Teaching methods for different knowledge module were determined, which included lecture, demonstration, case discussion, drill and sand table simulation. And the evaluation methods were affirmed as a quiz, written examination, skill test and teamwork test assessed by intra-group and inter-group evaluation.
Through scientific investigation of experts in disaster rescue and undergraduates majoring in clinical medicine, a disaster medicine course model for clinical medical students was established.
Positron annihilation spectroscopy and differential scanning calorimetry were used to evaluate the changes of the atomic configurations in Zr-based metallic glasses (MGs) due to alloying and plastic deformation. The correlation between the atomic configurations of MGs and the amorphous-to-icosahedral phase transition due to heating was investigated. The results indicate that the free volume frozen in the as-cast Zr60Al15Ni25, Zr65Al7.5Ni10Cu17.5, and Zr65Al7.5Ni10Cu17.5Ag5 MGs substantially decreases in sequence. More excess free volume is introduced in Zr65Al7.5Ni10Cu17.5Ag5 MG due to cold rolling and milling. The annihilation of free volume due to alloying considerably stabilizes the icosahedral structure of MGs, which enhances the nucleation and growth of quasicrystals upon heating. However, the nucleation and growth of quasicrystals are considerably suppressed in Zr65Al7.5Ni10Cu17.5Ag5 MG due to cold rolling and milling, during which the more introduced excess free volume results in substantial destruction of short-range order with 5-fold symmetry. The present work further provides direct evidence for the prevalence of icosahedral short-range order in MGs.
Few studies have evaluated the relationships between intake of sugar-sweetened beverages (SSB) and intermediate biomarkers of cardiometabolic risk. Associations between artificially sweetened beverages (ASB) and fruit juice with cardiometabolic biomarkers are also unclear. We investigated habitual SSB, ASB and fruit juice intake in relation to biomarkers of hepatic function, lipid metabolism, inflammation and glucose metabolism. We analysed cross-sectional data from 8492 participants in the Nurses’ Health Study who were free of diabetes and CVD. Multivariate linear regression was used to assess the associations of SSB, ASB and fruit juice intake with concentrations of fetuin-A, alanine transaminase, γ-glutamyl transferase, TAG, HDL-cholesterol, LDL-cholesterol, total cholesterol, C-reactive protein (CRP), intracellular adhesion molecule 1 (ICAM-1), vascular cell adhesion protein 1, adiponectin, insulin and HbA1c as well as total cholesterol:HDL-cholesterol ratio. More frequent intake of SSB was significantly associated with higher concentrations of fetuin-A, TAG, CRP, ICAM-1, adiponectin and insulin, a higher total cholesterol:HDL-cholesterol ratio, and a lower concentration of HDL-cholesterol (Ptrend ranges from <0·0001 to 0·04) after adjusting for demographic, medical, dietary and lifestyle variables. ASB intake was marginally associated with increased concentrations of CRP (Ptrend=0·04) and adiponectin (Ptrend=0·01). Fruit juice intake was associated with increased concentrations of TAG and HbA1c and a lower concentration of adiponectin (Ptrend ranges from <0·0001 to 0·01). In conclusion, habitual intake of SSB was associated with adverse levels of multiple cardiometabolic biomarkers. Associations between ASB and fruit juice with cardiometabolic risk markers warrant further exploration.
Previous studies show inconsistent associations between α-linolenic acid (ALA) and risk of CHD. We aimed to examine an aggregate association between ALA intake and risk of CHD, and assess for any dose–response relationship. We searched the PubMed, EMBASE and Web of Science databases for prospective cohort studies examining associations between ALA intake and CHD, including composite CHD and fatal CHD. Data were pooled using random-effects meta-analysis models, comparing the highest category of ALA intake with the lowest across studies. Subgroup analysis was conducted based on study design, geographic region, age and sex. For dose–response analyses, we used two-stage random-effects dose–response models. In all, fourteen studies of thirteen cohorts were identified and included in the meta-analysis. The pooled results showed that higher ALA intake was associated with modest reduced risk of composite CHD (risk ratios (RR)=0·91; 95 % CI 0·85, 0·97) and fatal CHD (RR=0·85; 95 % CI 0·75, 0·96). The analysis showed a J-shaped relationship between ALA intake and relative risk of composite CHD (χ2=21·95, P<0·001). Compared with people without ALA intake, only people with ALA intake <1·4 g/d showed reduced risk of composite CHD. ALA intake was linearly associated with fatal CHD – every 1 g/d increase in ALA intake was associated with a 12 % decrease in fatal CHD risk (95 % CI −0·21, −0·04). Though a higher dietary ALA intake was associated with reduced risk of composite and fatal CHD, the excess composite CHD risk at higher ALA intakes warrants further investigation, especially through randomised controlled trials.
The aim of the present work was to determine maternal and fetal outcomes of intrahepatic cholestasis of pregnancy (ICP) in twin pregnancies. All twin pregnancies delivered above 28 gestational weeks in West China Second University Hospital from January 2013 to May 2015 were included. Data on maternal demographics and obstetric complications together with fetal outcomes were collected. The risk of adverse maternal and fetal outcomes were determined in relation to ICP by crude odds ratios (OR) and adjusted ORs (aOR) with 95% confidence intervals (CI). Subgroup analysis concentrated on the effect of assisted reproductive technology (ART), ICP severity, and onset time. A total of 1,472 twin pregnancies were included, of which 362 were cholestasis patients and 677 were conceived by ART. Higher rates of preeclampsia (aOR 1.96; 95% CI 1.35, 2.85), meconium-stained amniotic fluid (aOR 3.10; 95% CI 2.10, 4.61), and preterm deliveries (aOR 3.20; 95% CI 2.35, 4.37) were observed in ICP patients. Subgroup analysis revealed higher incidences of adverse outcomes in severe and early onset ICP groups. In conclusion, adverse maternal and fetal outcomes were strongly associated with ICP in twin patients. Active management and close antenatal monitoring are needed, especially in the early onset and severe groups.
In this study, the effects of Sm on the microstructure and corrosion resistance of hot-extruded AZ61 magnesium alloys were investigated by optical microscopy, scanning electron microscopy, and transmission electron microscopy. The results showed that uniformly dispersed Al2Sm particles with size of ∼2 μm were discovered in the hot-extruded AZ61 magnesium alloy sample modified with 1.0 wt% Sm, which promoted dynamic recrystallization grain growth during the hot-extruded process, gradually increasing the grain of the alloy as Sm content increased. The morphology of the corroded surface and the corrosion rate of the hot-extruded AZ61 magnesium alloy both were significantly improved after Sm addition. The alloy sample modified with 2.0 wt% Sm after immersion in 3.5 wt% NaCl solution for 12 h showed minimum corrosion rate value, 3.1 mg/cm2 day, which is only 3.7% of the corrosion rate of unmodified alloy (82 mg/cm2 day).
Previous studies have reported that the first polar body (PB1) morphology reflects embryo development competence, but the effects of PB1 on porcine embryo development remain unknown. This study aims to determine whether the ability of porcine embryo development is related to oocytes’ PB1 in vitro. The distribution of type II cortical granules (CGs) of porcine matured oocytes in grade B PB1 is significantly greater compared with those in grades A and C PB1 (71.43% versus 52.46% and 50%; P < 0.05). The ratio of porcine parthenogenetic blastocysts and the mean cell number in each blastocyst in the group with grade B PB1 is significantly greater than that with grades A and C PB1 (30.81% vs. 19.02% and 15.15%; P < 0.05) and (36.67 versus 24.67, 28.67; P < 0.05), and no significant differences are found in the embryo cleavage for all groups (79.75%, 84.30%, and 78.18% in grades A, B, and C PB1; P > 0.05). The acetylation level of porcine embryos in the group with grade B PB1 is significantly greater compared with those in the other groups (P < 0.05), and is almost 2.5 times higher than that in grade A. Therefore, porcine oocytes with PB1 in grade B are more competitive in cytoplasmic maturation and further embryo development in vitro.
Carnitine has been reported to improve growth performance and reduce body lipid content in fish. Thus, we hypothesised that carnitine supplementation can improve growth performance and reduce lipid content in the liver and muscle of yellow catfish (Pelteobagrus fulvidraco), a commonly cultured freshwater fish in inland China, and tested this hypothesis in the present study. Diets containing l-carnitine at three different concentrations of 47 mg/kg (control, without extra carnitine addition), 331 mg/kg (low carnitine) and 3495 mg/kg (high carnitine) diet were fed to yellow catfish for 8 weeks. The low-carnitine diet significantly improved weight gain (WG) and reduced the feed conversion ratio (FCR). In contrast, the high-carnitine diet did not affect WG and FCR. Compared with the control diet, the low-carnitine and high-carnitine diets increased lipid and carnitine contents in the liver and muscle. The increased lipid content in the liver could be attributed to the up-regulation of the mRNA levels of SREBP, PPARγ, fatty acid synthase (FAS) and ACCa and the increased activities of lipogenic enzymes (such as FAS, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and malic enzyme) and to the down-regulation of the mRNA levels of the lipolytic gene CPT1A. The increased lipid content in muscle could be attributed to the down-regulation of the mRNA levels of the lipolytic genes CPT1A and ATGL and the increased activity of lipoprotein lipase. In conclusion, in contrast to our hypothesis, dietary carnitine supplementation increased body lipid content in yellow catfish.
The modification of near-eutectic Al–Si alloy with samarium additions (0–0.9 wt.% content) has been studied. The thermal analysis results indicated that the addition of Sm in Al–12Si alloy caused a depression of eutectic temperature (∆TE). And it was found that Sm was capable of breaking down the primary α-A1 phases, giving rise to an increment in the number of dendrites. Simultaneous primary Si refinement and eutectic modification were achieved by Sm addition. When 0.6 wt.% Sm was added to the alloy, the silicon in Al–12Si alloy was best refined and showed a fully modified, fine fibrous eutectic structure; the primary α-Al phase appears as a slightly dual dendritic-cellular nature and a pine-tree structure. Moreover, the mechanical properties were investigated by the tensile test. A good combination of ultimate tensile strength (217 MPa) and elongation (1.3%) was obtained when the addition of Sm was up to 0.6 wt.%.
People from lower socioeconomic groups have a higher risk of mortality. The impact of low socioeconomic status on survival among older adults with dementia and depression remains unclear.
To investigate the association between socioeconomic status and mortality in people with dementia and late-life depression in China.
Using Geriatric Mental Status – Automated Geriatric Examination for Computer Assisted Taxonomy (GMS-AGECAT) we interviewed 2978 people aged ⩾60 years in Anhui, China. We characterised baseline socioeconomic status and risk factors and diagnosed 223 people with dementia and 128 with depression. All-cause mortality was followed up over 5.6 years.
Individuals with dementia living in rural areas had a three times greater risk of mortality (multivariate adjusted hazard ratio (HR) = 2.96, 95% CI 1.45–6.04) than those in urban areas, and for those with depression the HR was 4.15 (95% CI 1.59–10.83). There were similar mortality rates when comparing people with dementia with low v. high levels of education, occupation and income, but individuals with depression with low v. high levels had non-significant increases in mortality of 11%, 50% and 55% respectively.
Older adults with dementia and depression living in rural China had a significantly higher risk of mortality than urban counterparts. Interventions should be implemented in rural areas to tackle survival inequality in dementia and depression.
Determinants for undetected dementia and late-life depression have been not well studied.
To investigate risk factors for undetected dementia and depression in older communities.
Using the method of the 10/66 algorithm, we interviewed a random sample of 7072 participants aged ⩽60 years in six provinces of China during 2007–2011. We documented doctor-diagnosed dementia and depression in the interview. Using the validated 10/66 algorithm we diagnosed dementia (n = 359) and depression (n = 328).
We found that 93.1% of dementia and 92.5% of depression was undetected. Both undetected dementia and depression were significantly associated with low levels of education and occupation, and living in a rural area. The risk of undetected dementia was also associated with ‘help available when needed‘, and inversely, with a family history of mental illness and having functional impairment. Undetected depression was significantly related to female gender, low income, having more children and inversely with having heart disease.
Older adults in China have high levels of undetected dementia and depression. General socioeconomic improvement, associated with mental health education, targeting high-risk populations are likely to increase detection of dementia and depression in older adults, providing a backdrop for culturally acceptable service development.
Spermatogonial stem cells (SSCs) have the ability to self-renew and offer a pathway for genetic engineering of the male germ line. Cryopreservation of SSCs has potential value for the treatment of male infertility, spermatogonial transplantation, and so on. In order to investigate the cryopreservation effects of different cryoprotectants on murine SSCs, 0.2 M of low-density lipoproteins (LDL), trehalose and soybean lecithin were added to the cryoprotective medium, respectively, and the murine SSCs were frozen at −80°C or −196°C. The results indicated that the optimal recovery rates of murine SSCs in the cryoprotective medium supplemented with LDL, trehalose and soybean lecithin were 92.53, 76.35 and 75.48% at −80°C, respectively. Compared with freezing at −196°C, the optimum temperature for improvement of recovery rates of frozen murine SSCs, cryopreservation in three different cryoprotectants at −80°C, were 17.11, 6.68 and 10.44% respectively. The recovery rates of murine SSCs in the cryoprotective medium supplemented with 0.2 M LDL were significantly higher than that of other cryoprotectants (P < 0.05). Moreover, the recovery rates were demonstrated to be greater at −80°C compared with at −196°C (P < 0.05). In conclusion, 0.2 M of LDL could significantly protect murine SSCs at −80°C. In the freezing–thawing process, LDL is responsible for the cryopreservation of murine SSCs because it can form a protective film at the surface of membranes. However, more research is needed to evaluate and understand the precise role of LDL during the freezing–thawing of SSCs.
Super-luminous ionization front achieved by using axicon as focus lens is proposed to improve the transition-Cherenkov radiation of terahertz emitted from a femtosecond laser filament in air. Benefitted from the better coherent superposition of radiation electric field generated by dipole-like electron current behind the ionization front, the terahertz radiation in far zone is enhanced by one order when the velocity of ionization front exceeds the light speed. Moreover, the radiation spectrum extends toward high frequency and covers the entire terahertz gap.