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Permian faunal affinity in the Lhasa Block plays a critical role in reconstructing its paleogeographic evolution. Cisuralian and Guadalupian faunas have been described from the Lhasa Block, but very few Lopingian (late Permian) brachiopods have been reported so far. In this paper, a new diverse brachiopod fauna consisting of 17 species of 17 genera and an unidentifiable Orthotetoidea is described from the uppermost part of the Xiala Formation at the Aduogabu section in the central part of the Lhasa Block. The age of this fauna can be assigned to the Changhsingian (late Lopingian) as indicated by the associated foraminifers Colaniella parva (Colani, 1924) and Reichelina pulchra Miklukho-Maklay, 1954. Characteristic brachiopods include Spinomarginifera chengyaoyenensis Huang, 1932, Haydenella wenganensis (Huang, 1932), and Araxathyris cf. dilatatus Shen, He, and Zhu, 1992. They also generally suggest a Changhsingian age. Paleobiogeographically, this fauna is uniformly composed of typical Tethyan elements represented by Spinomarginifera Huang, 1932 and Haydenella Reed, 1944, and some cosmopolitan elements, but no typical cold-water taxa of Gondwanan affinity. This is in contrast to the contemporaneous brachiopod faunas from the Tethys Himalayan region that are characterized by typical cold-water taxa of Gondwanan affinity, e.g., Costiferina indica (Waagen, 1884), Retimarginifera xizangensis Shen et al., 2000, Neospirifer (Quadrospina) tibetensis Ding, 1962. Thus, it is strongly indicative that the Lhasa Block had drifted into a relatively warm-water regime during the Changhsingian. An analysis of the paleobiogeographic change of brachiopods in the Lhasa Block throughout the entire Permian further suggests that the Lhasa Block probably had rifted away from the northern peri-Gondwanan margin between the latest Cisuralian and middle Guadalupian, that is, the Neotethys Ocean had opened before middle Guadalupian.
The present study was undertaken to investigate the antiparasitic activity of extracellular products of Streptomyces albus. Bioactivity-guided isolation of chloroform extracts affording a compound showing potent activity. The structure of the compound was elucidated as salinomycin (SAL) by EI-MS, 1H NMR and 13C NMR. In vitro test showed that SAL has potent anti-parasitic efficacy against theronts of Ichthyophthirius multifiliis with 10 min, 1, 2, 3 and 4 h (effective concentration) EC50 (95% confidence intervals) of 2.12 (2.22–2.02), 1.93 (1.98–1.88), 1.42 (1.47–1.37), 1.35 (1.41–1.31) and 1.11 (1.21–1.01) mg L−1. In vitro antiparasitic assays revealed that SAL could be 100% effective against I. multifiliis encysted tomonts at a concentration of 8.0 mg L−1. In vivo test demonstrated that the number of I. multifiliis trophonts on Erythroculter ilishaeformis treated with SAL was markedly lower than that of control group at 10 days after exposed to theronts (P < 0.05). In the control group, 80% mortality was observed owing to heavy I. multifiliis infection at 10 days. On the other hand, only 30.0% mortality was recorded in the group treated with 8.0 mg L−1 SAL. The median lethal dose (LD50) of SAL for E. ilishaeformis was 32.9 mg L−1.
Sedative–hypnotic medication use has been related to severe adverse events and risks. This study investigated the prevalence of and characteristics associated with the use of sedatives and hypnotics among community-dwelling elderly persons aged 65 years and over in Taiwan.
A representative sample of community-dwelling adults was recruited. Clinical and sociodemographic data were collected for assessing physical, mental, and cognitive functioning and disorders. Sedatives and hypnotics use was determined via both self-reporting and prescription records. Logistic regression modeling was used to evaluate associations between sedative–hypnotic use and demographic and health status.
Among the 3,978 participants aged 65 years and over, the rate of sedative–hypnotic use was 19.7% (n = 785). 4.5% (n = 35) of users reported sedative–hypnotic use without a doctor's prescription. Several sociodemographic characteristics were positively associated with sedative and hypnotic use, including older age, female gender, higher education level, married status, unemployment, and current alcohol consumption. Comorbid chronic and cardiovascular diseases, mental illness, depression, pain, and sleep problems also increased the likelihood of sedative–hypnotic use.
This study is one of the largest pioneer studies to date to survey sedatives–hypnotics use among community-dwelling elderly. One in five community-dwelling older adults reported sedative–hypnotic drugs use in Taiwan, and about 5% of sedative and/or hypnotics usage was without a doctor's prescription. Findings could be helpful for drug-use safety interventions to identify target geriatric patients who are in general at higher risk of downstream harm associated with sedative–hypnotic use in geriatric patients.
Apathy is a condition characterized by a lack of motivation that manifests in emotional, behavioral, and cognitive domains. Although previous studies have indicated that apathy is associated with frontal lesions, few studies have focused on the different subdomains of apathy, and no in vivo human biochemical data have been obtained to examine the neurochemical changes related to apathy in patients with Alzheimer's disease (AD). Thus, we investigated the frontal neurochemical alterations related to apathy among patients with AD using proton magnetic resonance spectroscopy (1H MRS).
Apathy was assessed through the Apathy Evaluation Scale (AES). 1H MRS was performed to measure neurochemical metabolite levels in the anterior cingulate region and right orbitofrontal region. Associations between neurochemical metabolites and the total score and subscores of each domain of the AES were analyzed.
Altogether, 36 patients completed the study. Patients with lower N-acetylaspartate/creatine ratios (NAA/Cr) in the anterior cingulate region demonstrated higher total apathy scores (β = −0.56, p = 0.003) with adjustments for age, gender, educational level, dementia severity, and depression severity. In a further analysis, a lower NAA/Cr in the anterior cingulate region was associated with all subdomains of apathy, including cognition (β = −0.43, p = 0.028), behavior (β = −0.55, p = 0.002), and emotion (β = −0.50, p = 0.005). No statistically significant associations were discovered in the right orbitofrontal region.
Our results suggest that apathy, in each of its cognitive, behavioral, or emotional subdomains is associated with brain neurochemical alterations in the anterior cingulate region. Abnormal neuronal integrity over the anterior cingulate cortex may exhibit a central role in causing all aspects of apathy in patients with AD.
Massively parallel sequencing (MPS) technology has become increasingly available
and has been widely used to screen for trisomies 21, 18, and 13 in singleton
pregnancies. This study assessed the performance of MPS testing of cell-free
fetal DNA (cffDNA) from maternal plasma for trisomies 21, 18, and 13 in twin
pregnancies. Ninety-two women with twin pregnancies were recruited. The results
were identified through karyotypes of amniocentesis or clinical examination and
follow-up of the neonates. Fluorescent in-situ hybridization was used to examine
the placentas postnatally in cases of false-positive results. The fetuses with
autosomal trisomy 21 (n = 2) and trisomy 15 (n
= 1) were successfully detected via MPS testing of cffDNA. There was one
false-positive for trisomy 13 (n = 1), and fluorescence in-situ
hybridization (FISH) identified confined placental mosaicism in this case. For
twin pregnancies undergoing second-trimester screening for trisomy, MPS testing
of cffDNA is feasible and can enhance the diagnostic spectrum of non-invasive
prenatal testing, which could effectively reduce invasive prenatal diagnostic
methods. In addition to screening for trisomy 21, 18, and 13 by cffDNA, MPS can
detect fetal additional autosomal trisomy. False-positive results cannot
completely exclude confined placental mosaicism.
This study was conducted to estimate prevalence rates and risk factors for late-life depression in a large nationwide representative sample from Taiwan.
A total of 5,664, randomly sampled individuals aged ≥55 years were enrolled. Clinically, relevant depressive symptoms were classified using the Center for Epidemiological Studies Depression Scale (CES-D score ≥16), and major depression was confirmed using the Primary Care Evaluation of Mental Disorders. Individuals with clinically relevant depressive symptoms, who did not meet the strict diagnostic criteria for major depression, were considered to have minor depression. Multinomial logistic regression analyses were conducted to identify risk factors for major and minor depression, including socio-demographic characteristics, medical conditions, lifestyle behaviors, social support network, and life events.
The prevalence rates of minor and major depression were 3.7% and 1.5%, respectively. Major depression was associated with personal vulnerability factors, such as poor social support, cognitive impairment, comorbid pain conditions, and sleep disturbance. However, minor depression was more likely to be related to adverse life events, including increased burden on families, changes in health status, or relationship problem. Approximately, 20.0% of individuals with major depression received antidepressant treatment.
Late-life depression was less prevalent among community-dwelling older adults in Taiwan than among populations in other countries. Our findings may aid the early detection and treatment of late-life depression and provide a basis for future investigations.
The prevalence of CHD has been well described worldwide except in Tibet. This study aimed to illustrate the prevalence and composition of CHD in Tibetan children according to altitude.
Methods and results
In the first part, we prospectively recruited 7088 unselected Tibetan children (4–17 years) from south-west Tibet. The total prevalence of CHD increased from 4.6/1000 below 4200 m to 13.4/1000 above 4700 m, with a female-to-male ratio of 1.3:3.1. The total prevalence and female prevalence of patent ductus arteriosus increased more than 10-fold. Females living above 4700 m had exceptionally high prevalence of patent ductus arteriosus (14.9/1000). The prevalence of atrial septal defect was comparable among different altitudes (3.3–3.8/1000). The prevalence of ventricular septal defect was 1.3/1000 below 4700 m, and no cases were found above this altitude. In the second part, we retrospectively reviewed the clinical data of 383 CHD children in Tibet and 73 children at lower altitudes. The percentage of isolated ventricular septal defect decreased from 54.8 to 3.1%, and the percentage of isolated patent ductus arteriosus increased from 8.2 to 68.4% with elevation. Children living below 4200 m (10.4–13.7%) had a larger proportion of complex CHD than those above this altitude (2.0–3.1%). Of the 20 Tibetan children with complex CHD, 14 (70.0%) lived below 4200 m.
A wide variation in CHD prevalence and composition existed in Tibetan children among different altitudes.
We aimed to clarify whether invasive dental treatment is associated with increased risk of prosthetic joint infection (PJI) and whether prophylactic antibiotics may lower the infection risk remain unclear.
Retrospective cohort study.
All Taiwanese residents (N=255,568) who underwent total knee or hip arthroplasty between January 1, 1997, and November 30, 2009, were screened.
The dental cohort consisted of 57,066 patients who received dental treatment and were individually matched 1:1 with the nondental cohort by age, sex, propensity score, and index date. The dental cohort was further divided by the use or nonuse of prophylactic antibiotics. The antibiotic and nonantibiotic subcohorts comprised 6,513 matched pairs.
PJI occurred in 328 patients (0.57%) in the dental subcohort and 348 patients (0.61%) in the nondental subcohort, with no between-cohort difference in the 1-year cumulative incidence (0.6% in both, P=.3). Multivariate-adjusted Cox regression revealed no association between dental procedures and PJI. Furthermore, PJI occurred in 13 patients (0.2%) in the antibiotic subcohort and 12 patients (0.18%) in the nonantibiotic subcohorts (P=.8). Multivariate-adjusted analyses confirmed that there was no association between the incidence of PJI and prophylactic antibiotics.
The risk of PJI is not increased following dental procedure in patients with hip or knee replacement and is unaffected by antibiotic prophylaxis.
Methods of imaging and image analysis are presented for dusty plasma experiments. Micron-sized polymer spheres, electrically suspended in a partially ionized gas, are illuminated by a sheet of laser light and imaged by video cameras. Image analysis methods yield particle positions and velocities of individual particles in each video image. Methods to minimize errors in the particle positions and velocities, which are now commonly used in the dusty plasma community, are described.
In this paper, we study the following Kirchhoff-type equation:
where a, b are positive constants and N = 1, 2, 3. Under appropriate assumptions on V, K and g, we obtain a ground-state solution by using the approach developed by Szulkin and Weth in 2010.
Objective: To study the relationship of Nε-(carboxymethyl)-lysine level (CML) with microstructure changes of white matter (WM), and cognitive impairment in patients with type 2 diabetes mellitus (T2DM) and to discuss the potential mechanism underlying T2DM-associated cognitive impairment. Methods: The study was performed in T2DM patients (n=22) with disease course ≥5 years and age ranging from 65 to 75 years old. A control group consisted of 25 sex- and age-matched healthy volunteers. Fractional anisotropy (FA) of several WM regions was analyzed by diffusion tensor imaging scan. Plasma CML levels were measured by enzyme-linked immunosorbent assay, and cognitive function was assessed by Mini-Mental State Examination and Montreal cognitive assessment (MoCA). Results: The total Mini-Mental State Examination score in the patient group (25.72±3.13) was significantly lower than the control group (28.16±2.45) (p<0.05). In addition, the total MoCA score in the patient group (22.15±3.56) was significantly lower than the control group 25.63±4.12) (p<0.01). In the patient group, FA values were significantly decreased in the corpus callosum, cingulate fasciculus, inferior fronto-occipital fasciculus, parietal WM, hippocampus, and temporal lobes relative to corresponding regions of healthy controls (p<0.05). Plasma CML level was negatively correlated with average FA values in the global brain (r=−0.58, p<0.01) and MoCA scores (r=−0.47, p<0.05). Conclusions: In T2DM, WM microstructure changes occur in older patients, and elevations in CML may play a role in the development of cognitive impairment.
Several previous cross-sectional studies have shown that vegetarians have a better metabolic profile than non-vegetarians, suggesting that a vegetarian dietary pattern may help prevent chronic degenerative diseases. However, longitudinal studies on the impact of vegetarian diets on metabolic traits are scarce. We studied how several sub-types of vegetarian diets affect metabolic traits, including waist circumference, BMI, systolic blood pressure (SBP), diastolic blood pressure, fasting blood glucose, total cholesterol (TC), HDL, LDL, TAG and TC:HDL ratio, through both cross-sectional and longitudinal study designs. The study used the MJ Health Screening database, with data collected from 1994 to 2008 in Taiwan, which included 4415 lacto-ovo-vegetarians, 1855 lacto-vegetarians and 1913 vegans; each vegetarian was matched with five non-vegetarians based on age, sex and study site. In the longitudinal follow-up, each additional year of vegan diet lowered the risk of obesity by 7 % (95 % CI 0·88, 0·99), whereas each additional year of lacto-vegetarian diet lowered the risk of elevated SBP by 8 % (95 % CI 0·85, 0·99) and elevated glucose by 7 % (95 % CI 0·87, 0·99), and each additional year of ovo-lacto-vegetarian diet increased abnormal HDL by 7 % (95 % CI 1·03, 1·12), compared with non-vegetarians. In the cross-sectional comparisons, all sub-types of vegetarians had lower likelihoods of abnormalities compared with non-vegetarians on all metabolic traits (P<0·001 for all comparisons), except for HDL and TAG. The better metabolic profile in vegetarians is partially attributable to lower BMI. With proper management of TAG and HDL, along with caution about the intake of refined carbohydrates and fructose, a plant-based diet may benefit all aspects of the metabolic profile.
We present calculation of critical voltage for AlGaN/GaN high electron mobility transistors (HEMTs) with GaN cap layer. The calculation includes mechanical stress and relaxable energy in the GaN/AlGaN barrier layer. Under high voltage conditions, the high electric field results in an increase in stored relaxable energy. If this exceeds a critical value, crystallographic defects are formed. This degradation mechanism is voltage driven and characterized by a critical voltage beyond which non-reversible degradation takes place. The dependence of the GaN cap layer’s thickness on the critical voltage has been discussed. The calculated results indicate that thicker GaN cap layer results in higher critical voltage.
A theoretical study of transconductance characteristics (gm − Vgs profile) of AlGaN/GaN high electron mobility transistors (HEMTs) with a graded AlGaN layer is given in this paper. The calculations were made using a self-consistent solution of the Schrödinger-Poisson equations and an AlGaN/GaN HEMTs numerical device model. Transconductance characteristics of the devices are discussed while the thickness and Al composition of the graded AlGaN layer are optimized. It is found that graded AlGaN layer structure can tailor device’s gm − Vgs profile by improving polar optical phonon mobility and interface roughness mobility. Good agreement is obtained between the theoretical calculations and experimental measurements over the full range of applied gate bias.
Unawareness of deficits is common and is associated with poor outcomes in Alzheimer's disease (AD); however, little is known about correlated neurobiochemical changes.
Proton magnetic resonance spectroscopy was used to examine neurobiochemical correlates of unawareness of deficits as assessed by the Dementia Deficit Scale in 36 patients with AD. Magnetic resonance spectroscopy spectra were acquired from the anterior cingulate area and right orbitofrontal area. Concentrations of N-acetyl-aspartate (NAA), total creatine, and other neurometabolites were calculated.
Nineteen (52.8%) participants had relative unawareness of deficits. This condition was negatively correlated with NAA/creatine in the anterior cingulate area (β = −0.36, p = 0.025) and positively correlated with NAA/creatine in the right orbitofrontal area (β = 0.41, p = 0.009) after controlling for dementia severity.
These findings suggest unawareness of deficits in AD was associated with the altered neurochemical metabolites in the anterior cingulate area and right orbitofrontal area. However, the two areas might have opposite neuronal functions in unawareness of deficits.
A high open-circuit voltage (VOC) of an organic photovoltaic device (OPV) has been realized using an ultrathin electron donor layer, 2,3-Bis(2-(diphenylamino)-9,9′- spirobifluorene-7-yl)fumaronitrile (PhSPFN), which exhibits the most suitable and low-lying highest occupied molecular orbital (HOMO) to align between the anode and donor energy levels. The planar heterojunction OPV, represented as indium tin oxide electrode/PhSPFN/fullerene C60/bathocuproine/aluminum electrode shows high performance with a VOC of 0.91 V, short current density of 3.9 mA/cm2, fill factor of 56% and power conversion efficiency of 2% under an air-mass of 1.5 global illumination at 1 sun. In addition, the effect of the VOC change is discussed in terms of various donor materials. The VOC turns out to be restricted to the energetic alignment between the work function of the anode and the HOMO level, indicating that the optimization of VOC requires energetically good contact between the anode and organic materials.
The AlGaN/GaN/InGaN/GaN double heterojunction high electron mobility transistors (DH-HEMTs) sample has been grown by MOCVD on (0 0 0 1) sapphire substrate. The structure features a 7 nm In0.046Ga0.954N interlayer determined by Rutherford backscattering (RBS). Since the polarization field in the InGaN interlayer is opposite to it in the AlGaN layer, an additional potential barrier is introduced between the two-dimensional electron gas (2DEG) channel and buffer, leading to enhanced carrier confinement and improved buffer isolation. The GaN layers between the AlGaN layer and InGaN interlayer are divided into two layers consisting of GaN channel layer which provides high mobility 2DEG grown at 1070 °C and GaN spacer layer grown at the same temperature as InGaN interlayer (800 °C) to prevent indium diffusion. RBS measurement confirms that the 3 nm GaN spacer layer isolates the InGaN interlayer well and free from diffusion. Hall measurement has been performed, the mobility as high as 1552 cm2/V s at room temperature is obtained and the sheet carrier density is 1.55 × 1013 cm−2. The average sheet resistance is 331 Ω/sq, respectively. The mobility obtained in this paper is about 20% higher than similar structures reported.
Several limit laws for the Zagreb indices of the classical Erdös–Rényi random graphs are investigated in this paper. We have obtained the necessary and sufficient condition for the asymptotic normality of the two Zagreb indices (suitably normalized), as well as the explicit values for the means and variances of both the indices. Besides, the limiting joint distribution of the numbers of paths of various lengths is also studied under several conditions.
To date, there has been little improvement in cryopreservation of bull sperm due to lack of understanding of the freezing mechanisms. Therefore, this study set out to investigate expression levels of fertility-associated proteins in bull sperm, and in particular the relationship between the 90 kDa heat-shock protein (HSP90) and the sperm characteristics after freezing–thawing. Semen was collected from eight Holstein bulls by artificial vagina. Characteristics of these fresh semen, including sperm motility, morphology, viability and concentration, were evaluated. Sperm quality was also assessed after freezing–thawing. Eight ejaculates were divided into two groups based on freezing resistance and sperm motility. Sperm proteins were extracted and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) analysis and western blotting were performed. SDS-PAGE results showed that there was substantial diversity in 90 kDa proteins in the frozen–thawed sperm and HSP90 was confirmed as one of the 90 kDa proteins by western blot. This study indicated that HSP90 expression correlated positively with sperm quality. The amount of expressed 90 kDa proteins in the high freezing resistance (HFR) group was significantly higher than that in the low freezing resistance (LFR) group (P < 0.05). Thus, higher expression of HSP90 could probably lead to the higher motility and freezing resistance of sperm found after freezing–thawing. Therefore, we concluded that level of HSP90 expression could be used to predict reliably and simply the freezing resistance of bull sperm.
We report the fabrication of AlGaN/GaN high electron mobility transistors (MIS-HEMTs) with a high breakdown voltage by employing a metal-insulator-semiconductor (MIS) gate structure using Si3N4 insulator. The Si3N4 films were deposited by plasma enhanced chemical vapor deposition (PECVD) as the surface passivation, interlayer films and the gate dielectric. In comparison with Schottky-gate HEMTs, the gate leakage currents of MIS-HEMTs exhibited three orders of magnitude reduction. With similar device structures, the off-state breakdown voltage of MIS-HEMTs was 1050 V with a specific on-resistance of 4.0 mΩ cm2, whereas the breakdown voltage and specific on-resistance of SG-HEMTs were 740 V and 4.4 mΩ cm2, respectively. In addition, the MIS-HEMTs exhibited little current slump in the pulsed measurements and possessed faster switch speed than Si MOSFET. We demonstrate that AlGaN/GaN MIS-HEMTs are promising not only for microwave applications but also for high power switching applications.