Effects of gamma-ray irradiation on material and electrical properties of AlN gate dielectric on 4H-SiC.

This article investigates the radiation effects on as-deposited and annealed AlN films on 4H-SiC substrates under gamma-rays. The AlN films are prepared using plasma-enhanced-atomic-layer-deposition on an n-type 4H-SiC substrate. The AlN/4H-SiC MIS structure is subjected to gamma-ray irradiation with total doses of 0, 300, and 600 krad(Si). Physical, chemical, and electrical methods were employed to study the variations in surface morphology, charge transport, and interfacial trapping characteristics induced by irradiation. After 300 krad(Si) irradiation, the as-deposited and annealed samples exhibit their highest root mean square values of 0.917 nm and 1.190 nm, respectively, which is attributed to N vacancy defects induced by irradiation. Under irradiation, the flatband voltage (Vfb) of the as-deposited sample shifts from 2.24 to 0.78 V, while the annealed sample shifts from 1.18 to 2.16 V. X-ray photoelectron spectrum analysis reveals the decomposition of O-related defects in the as-deposited AlN and the formation of Al(NOx)ycompounds in the annealed sample. Furthermore, the space-charge-limits-conduction (SCLC) in the as-deposited sample is enhanced after radiation, while the barrier height of the annealed sample decreases from 1.12 to 0.84 eV, accompanied by the occurrence of the SCLC. The physical mechanism of the degradation of electrical performance in irradiated devices is the introduction of defects like N vacancies and O-related defects like Al(NOx)y. These findings provide valuable insights for SiC power devices in space applications.

Multiparametric MRI radiomics improves preoperative diagnostic performance for local staging in patients with endometrial cancer.

PURPOSE: To determine whether multiparametric magnetic resonance imaging (MRI) radiomics-based machine learning methods can improve preoperative local staging in patients with endometrial cancer (EC). METHODS: Data of patients with histologically confirmed EC who underwent preoperative MRI were retrospectively analyzed and divided into a training or test set. Radiomic features extracted from multiparametric MR images were used to train and test the prediction of deep myometrial invasion (DMI) and cervical stromal invasion (CSI). Two radiologists assessed the presence of DMI and CSI on conventional MR images. A combined model incorporating a radiomic signature and conventional MR images was constructed and presented as a nomogram. Performance of the predictive models was assessed using the area under curve (AUC) in the receiver operating curve analysis and pairwise comparison using DeLong's test with Bonferroni correction. RESULTS: This study included 198 women (training set = 138, test set = 60). Conventional MRI achieved AUCs of 0.837 and 0.799 for detecting DMI and 0.825 and 0.858 for detecting CSI in the training and test sets, respectively. The nomogram achieved AUCs of 0.928 and 0.869 for detecting DMI and 0.913 and 0.937 for detecting CSI in the training and test sets, respectively. The ability of the nomogram to detect DMI and CSI in the two sets was superior to that of conventional MRI (adjusted p < 0.05), except for the ability to detect CSI in the test set (adjusted p > 0.05). CONCLUSION: A nomogram incorporating radiomics signature into conventional MRI improved the efficacy of preoperative local staging of EC.

Quality of Health Economic Evaluations in Mainland China: A Comparison of Peer-Reviewed Articles in Chinese and in English.

OBJECTIVE: Our objective was to assess the incidence and quality of reporting of published health economic evaluations in mainland China and compare the quality of peer-reviewed articles in Chinese and English. METHODS: A comprehensive search was conducted for economic evaluations pertaining to China published from 2006 to 2015 using the PubMed, CBM, CMCC, CNKI, VIP, and Wanfang databases. All studies in English that met the inclusion criteria were included. For studies in Chinese, 200 sampled studies were included according to the random seeds method, and the same number of the most-cited studies in Chinese as those in English were included according to the number of citations and journal grades. Researchers independently assessed the quality of the studies using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklist. RESULTS: After literature search and screening, a total of 310 studies were identified. The majority of these studies were cost-effectiveness studies (82.26%). Scores among different CHEERS items varied greatly. There was a gap between the average quality scores of the studies published in Chinese and those published in English (49.78 ± 9.31 vs. 82.48 ± 17.69) and between the average quality scores of the included most-cited studies in Chinese and English, which was slightly smaller (54.08 ± 10.27 vs. 82.48 ± 17.69). The methods, results, and discussion sections of studies published in Chinese were of low quality. CONCLUSION: The quality of reporting of health economic evaluations in mainland China has developed slowly. Most of the included studies were incomplete in the presentation of content, making the results less reliable. It is important to standardize and improve the quality of Chinese health economic research.

Neuroligin1 Contributes to Neuropathic Pain by Promoting Phosphorylation of Cofilin in Excitatory Neurons.

Neuropathic pain is a kind of chronic pain that remains difficult to treat due to its complicated underlying mechanisms. Accumulating evidence has indicated that enhanced synaptic plasticity of nociceptive interneurons in the superficial spinal dorsal horn contributes to the development of neuropathic pain. Neuroligin1 (NL1) is a type of excitatory postsynaptic adhesion molecule, which can mediate excitatory synaptic activity, hence promoting neuronal activation. Vglut2 is the most common marker of excitatory glutamatergic neurons. To explore the role of NL1 in excitatory neurons in nociceptive regulation, we used transgenic mice with cre recombinase expression driven by the Vglut2 promoter combined with viral vectors to knockdown the expression of NL1 in excitatory neurons in the spinal dorsal horn. We found that NL1 was upregulated in the L4-L6 spinal dorsal horn in Vglut2-cre+/- mouse subjected to spared nerve injury (SNI). Meanwhile, the expression of phosphorylated cofilin (p-cofilin) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor subunit 1 (GluR1) was also increased. Spinal microinjection of a cre-dependent NL1-targeting RNAi in Vglut2-cre+/- mouse alleviated the neuropathic pain-induced mechanical hypersensitivity and reduced the increase in p-cofilin and GluR1 caused by SNI. Taken together, NL1 in excitatory neurons regulates neuropathic pain by promoting the SNI-dependent increase in p-cofilin and GluR1 in the spinal dorsal horn. Our study provides a better understanding of the role of NL1 in excitatory neurons, which might represent a possible therapeutic target for alleviating neuropathic pain.

Apigenin inhibits in vitro and in vivo tumorigenesis in cisplatin-resistant colon cancer cells by inducing autophagy, programmed cell death and targeting m-TOR/PI3K/Akt signalling pathway.

PURPOSE: Colon cancer is one of the deadly malignancies and the second most frequent cancer in the world. The development of drug resistance and dearth of the viable drug options forms an obstacle in the treatment of colon cancer. Herein, the anticancer potential of Apigenin was examined against cisplatin-resistant colon cancer cells. METHODS: The proliferation rate of the cisplatin-resistant colon cancer cell line HT-29 was assessed by WST-1 assay. Autophagy was detected by electron microscopy. Apoptotic cell death was analysed by propidium iodide (PI) staining. Cell cycle analysis was performed by flow cytometry. Protein expression was determined by immuno blotting. Xenografted mice models were used for in vivo evaluation of Apigenin. RESULTS: The results showed that Apigenin could considerably inhibit the proliferation of colon cancer cells. The anticancer activity of Apigenin against the HT-29 colon cancer cells was found to be due to induction of autophagy and apoptosis. The Apigenin-triggered apoptosis and autophagy were also linked with alteration in the apoptosis and autophagy-related protein expression. Furthermore, it was found that Apigenin could inhibit the m-TOR/PI3K/AKT signalling pathway in the cisplatin-resistant colon cancer cells. The effects of Apigenin were also examined in vivo in xenografted mice models and it was revealed that Apigenin inhibited the growth of xenografted tumors. CONCLUSIONS: Taken together, these results indicate that Apigenin could inhibit the growth of cisplatin-resistant colon cancer cells in vitro and in vivo and may be used for the improvement of therapy of colon cancer.

Educational attainment and mortality: results from the Sixth Population Census in China.

BACKGROUND: Health and education are two closely related factors that affect human development. A limited number of studies have been conducted in China, most of which have been based on small sample sizes and with inconsistent results. The study investigates the association between mortality rate and educational level in China based on the sixth national population census in 2010. METHODS: This is large-scale population study based on the nationally administrated data sets of population census in 2010, 2000 and 1990. The 2010 census covered a total population of 1 332 810,869 in China. RESULTS: In general, standardized mortality rate decreased as educational level increased. The standardized mortality rate is higher among males than among females with equivalent educational levels. The standardized mortality rate in all the educational groups declined to varying degrees from 1990. 2000 to 2010. The standardised mortality rate declined with increasing educational levels from no education to university undergraduate groups in 1990, 2000 and 2010. The standardized mortality rate declined as the degree of education increased in cities, towns, and villages, but gradually increased at the same educational level from cities, towns, to villages in general. The difference in each region is considerable and the population quality of the developed area is generally high. The percentage of the uneducated population to the total population aged 15 years and over (%) was positively correlated with the standardized mortality rate. By contrast, the percentage of the population with a high school education to the total population aged 6 years and over (%) was negatively correlated with the standardized mortality rate. CONCLUSIONS: We found that educational level was negatively correlated with the mortality rate. The crude and standardized death rate is lower among individuals with higher educational level. Together with previous research findings, this study indicates that improving total population education attainment remains an important challenge that requires imperative action, while reducing educational inequities remains crucial for the government.

Raman Spectroscopy of Multi-Layer Graphene epitaxially Grown on 4H-SiC by Joule Heat Decomposition.

We developed a Joule heating decomposition (JHD) method, which applied direct current on the SiC for the epitaxial growth of multi-layer graphene (MLG) films on Si-terminated (0001) face of the high doping 4H-SiC substrate. By this JHD method, the growth time for preparing MLG was only several minutes. Raman spectroscopy was employed to study the influence of the temperature caused by the Joule heating on the quality and the uniformity of the sample. Then, other properties, such as the strain, the layer's number, and the electric characteristics, of the MLG were studied in details. It was found that the quality of the MLG was substantially dependent on the growth temperature (operation current) and the growth time, while the layer's number was only dependent on the growth temperature but not the growth time. Finally, less-defect and homogeneous MLG (~ 45 layers) with an area of ~ 12 × 5 mm2 could be obtained at a heating temperature of ~ 1470 °C with duration time of 5 min. By using the linear transmission line method, the specific contact resistance of Au and MLG was 5.03 × 10-5 Ω cm2, and the sheet resistance was 52.36 Ω/sq, respectively.

Nanoscale avalanche photodiode with self-quenching and ultrahigh ultraviolet/visible rejection ratio.

A 4H-SiC based separate-absorption-multiplication (SAM) avalanche photodiode with a nanoscale multiplication region and a bulk absorption region is proposed and its optoelectronic performance is modeled. The results show that the avalanche breakdown voltage of the device is found to be dependent on the illumination condition. This is attributed to the existence of an illumination-dependent hole potential well in the upper center of the absorption region. Based on the illumination-dependence of avalanche breakdown voltage, a self-quenching and an ultrahigh UV/visible rejection ratio have been realized in this structure.

Breath figure lithography: A facile and versatile method for micropatterning.

We describe a facile method to micropattern solid substrates: breath figure lithography (BFL). A honeycomb structured gold mask was prepared by sputter-coating a micro-porous polymer film with BF arrays, and then inductively coupled plasma reactive ion etching (ICP-RIE) transferred the patterns onto silicon wafer. The large etching rate selectivity between golden mask and substrate plays an important role in the effective transfer of the patterns. The versatility of the method was demonstrated by forming micropatterns on various solid substrates with adjustable sizes. Furthermore, the micropatterns on solid substrate could be replicated by PDMS stamp.

Expression characteristic and significance of interleukin-6, nuclear factor kappa beta, and bone formation markers in rat models of osteoporosis.

The goal of this study was to investigate the expression levels of interleukin 6 (IL-6), nuclear factor kappa beta (NF-kappabeta), bone-specific alkaline phosphatase (BALP), and bone osteocalcin (BGP) in rats with osteoporosis and their significance in the pathogenesis of osteoporosis. In all, 60 adult female SD rats were divided randomly into 3 groups of 20 rats each: normal control group (control), sham-operated group (sham), and ovariectomized group (OVX). In 2, 3, 4, 5, and 6 months after surgery, 4 rats were randomized from each group for assays of BMD, IL-6, BALP, and BGP. Then, the rats were sacrificed for the detection of IL-6 and NF-kappabeta expression levels in bone tissue by quantitative real-time RT-PCR analysis. Compared with the sham (0.097 +/- 0.04 g/cm2, 0.097 +/- 0.01 g/cm2, 0.095 +/- 0.07 g/cm2) and control group (0.107 +/- 0.01 g/cm2, 0.103 +/- 0.07 g/cm2, 0.108 +/- 0.06 g/cm2), the BMD of rats in the OVX group was reduced remarkably in 4, 5, and 6 months (0.082 +/- 0.05 g/cm2, 0.073 +/- 0.02 g/cm2, 0.061 +/- 0.05 g/cm2, respectively; P < 0.01); the serum IL-6 level increased significantly from 2 to 6 months after surgery (P < 0.01); and the serum levels of BALP and BGP were greater at 4, 5, and 6 months (P < 0.05). The quantitative real-time RT-PCR analysis demonstrated that IL-6 and NF-kappabeta mRNA levels in OVX group increased in a time-dependent manner. Moreover, the IL-6, NF-kappabeta, BALP, and BGP levels were correlated negatively with the BMD. Meanwhile, a positive correlation was observed between IL-6 and NF-kappabeta. In conclusion, the expression levels of IL-6, NF-kappabeta, and bone formation markers may increase significantly in the osteoporosis rats. These molecules could play a role in the pathogenesis.