Photon orbits and phase transition for Non-Linear charged Anti-de Sitter black holes

In this work, we investigate the relationship between the photon sphere radius and the first-order phase transition for the charged EPYM AdS black hole. Through the analysis, we find with a certain condition there exist the non-monotonic behaviors between the photon sphere radius, the impact parameter, the non-linear YM charge parameter, temperature, and pressure. And both the changes of photon sphere radius and impact parameter before and after phase transition can be regarded as the order parameter, their critical exponents near the critical point are equal to the same value $1/2$, just like the ordinary thermal systems. These indicate that there maybe exists a universal relationship of gravity nearby the critical point for a black hole thermodynamical system. Furthermore, the effect of impact parameter on the deflect angle is also investigated

The UDP-glucosyltransferase multigene family in Bombyx mori

<p>Abstract</p> <p>Background</p> <p>Glucosidation plays a major role in the inactivation and excretion of a great variety of both endogenous and exogenous compounds. A class of UDP-glycosyltransferases (UGTs) is involved in this process. Insect UGTs play important roles in several processes, including detoxication of substrates such as plant allelochemicals, cuticle formation, pigmentation, and olfaction. Identification and characterization of <it>Bombyx mori </it>UGT genes could provide valuable basic information for this important family and explain the detoxication mechanism and other processes in insects.</p> <p>Results</p> <p>Taking advantage of the newly assembled genome sequence, we performed a genome-wide analysis of the candidate UGT family in the silkworm, <it>B. mori</it>. Based on UGT signature and their similarity to UGT homologs from other organisms, we identified 42 putative silkworm UGT genes. Most of them are clustered on the silkworm chromosomes, with two major clusters on chromosomes 7 and 28, respectively. The phylogenetic analysis of these identified 42 UGT protein sequences revealed five major groups. A comparison of the silkworm UGTs with homologs from other sequenced insect genomes indicated that some UGTs are silkworm-specific genes. The expression patterns of these candidate genes were investigated with known expressed sequence tags (ESTs), microarray data, and RT-PCR method. In total, 36 genes were expressed in tissues examined and showed different patterns of expression profile, indicating that these UGT genes might have different functions.</p> <p>Conclusion</p> <p><it>B. mori </it>possesses a largest insect UGT gene family characterized to date, including 42 genes. Phylogenetic analysis, genomic organization and expression profiles provide an overview for the silkworm UGTs and facilitate their functional studies in future.</p

Microstructure and structural modulation of lutetium dihydride LuH2 as seen via transmission electron microscopy

Structural investigations conducted using transmission electron microscopy (TEM) on LuH2 synthesized under atmospheric pressure (AP-LuH2) and nitrogen-doped LuH2 synthesized under high pressure (HP-LuH2) have revealed numerous microstructural phenomena. Both materials show a clear superstructure modulation with wave vector, q^* = 1/4 (2-20), and this modulation can be well interpreted by the displacements of Lu atoms. Further investigations on the nitrogen-doped HP-LuH2 materials reveal the appearance of high-density antiphase boundaries, in particular, domain walls of a few atomic layer thickness without structural modulation can be observed, suggesting possible interface properties could be detected in this system. In-situ TEM observations of AP-LuH2 suggest that no evident structural phase transition occurs between 94 K and 673 K.Comment: 8 pages, 7 figure

Parent-adolescent interaction and risk of adolescent internet addiction: a population-based study in Shanghai

Abstract Background Family-based intervention is essential for adolescents with behavioral problems. However, limited data are available on the relationship between family-based factors and adolescent internet addiction (AIA). We aimed to examine this relationship using a representative sample of Shanghai adolescents. Methods In October 2007, a total of 5122 adolescents were investigated from 16 high schools via stratified-random sampling in Shanghai. Self-reported and anonymous questionnaires were used to assess parent-adolescent interaction and family environments. AIA was assessed by DRM-52 Scale, developed from Young’s Internet-addiction Scale, using seven subscales to evaluate psychological symptoms of AIA. Results Adjusting for adolescents’ ages, genders, socio-economic status, school performances and levels of the consumption expenditure, strong parental disapproval of internet-use was associated with AIA (vs. parental approval, OR = 2.20, 95% CI: 1.24-3.91). Worse mother-adolescent relationships were more significantly associated with AIA (OR = 3.79, 95% CI: 2.22-6.48) than worse father-adolescent relationships (OR = 1.76, 95% CI: 1.10-2.80). Marital status of “married-but-separated” and family structure of “left-behind adolescents” were associated with symptoms of some subscales. When having high monthly allowance, resident students tended to develop AIA but commuter students did not. Family social-economic status was not associated with the development of AIA. Conclusions The quality of parent-adolescent relationship/communication was closely associated with the development of AIA, and maternal factors were more significantly associated with development of AIA than paternal factors. Family social-economic status moderated adolescent internet-use levels but not the development of AIA.http://deepblue.lib.umich.edu/bitstream/2027.42/109471/1/12888_2014_Article_1616.pd

Enhanced Photoluminescence Emission and Thermal Stability from Introduced Cation Disorder in Phosphors

Optimizing properties of phosphors for use in white-light-emitting diodes (WLEDs) is an important materials challenge. Most phosphors have a low level of lattice disorder due to mismatch between the host and activator cations. Here we show that deliberate introduction of high levels of cation disorder leads to significant improvements in quantum efficiency, stability to thermal quenching, and emission lifetime in Sr_{1.98–<i>x</i>}(Ca_0.55Ba_0.45)_<i>x</i>Si₅N₈:Eu_0.02 (<i>x</i> = 0–1.5) phosphors. Replacing Sr by a (Ca_0.55Ba_0.45) mixture with the same average radius increases cation size variance, resulting in photoluminescence emission increases of 20–26% for the <i>x</i> = 1.5 sample relative to the <i>x</i> = 0 parent across the 25–200 °C range that spans WLED working temperatures. Cation disorder suppresses nonradiative processes through disruption of lattice vibrations and creates deep traps that release electrons to compensate for thermal quenching. Introduction of high levels of cation disorder may thus be a very useful general approach for improving the efficiency of luminescent materials

Personal characteristics related to the risk of adolescent internet addiction: a survey in Shanghai, China

Abstract Background Paralleling the rapid growth in computers and internet connections, adolescent internet addiction (AIA) is becoming an increasingly serious problem, especially in developing countries. This study aims to explore the prevalence of AIA and associated symptoms in a large population-based sample in Shanghai and identify potential predictors related to personal characteristics. Methods In 2007, 5,122 adolescents were randomly chosen from 16 high schools of different school types (junior, senior key, senior ordinary and senior vocational) in Shanghai with stratified-random sampling. Each student completed a self-administered and anonymous questionnaire that included DRM 52 Scale of Internet-use. The DRM 52 Scale was adapted for use in Shanghai from Young’s Internet Addiction Scale and contained 7 subscales related to psychological symptoms of AIA. Multiple linear regression and logistic regression were both used to analyze the data. Results Of the 5,122 students, 449 (8.8%) were identified as internet addicts. Although adolescents who had bad (vs. good) academic achievement had lower levels of internet-use (p 100 RMB (all p-values <0.05). Adolescents tended to develop AIA and show symptoms in all subscales when they spent more hours online weekly (however, more internet addicts overused internet on weekends than on weekdays, p < 0.0001) or when they used the internet mainly for playing games or real-time chatting. Conclusions This study provides evidence that adolescent personal factors play key roles in inducing AIA. Adolescents having aforementioned personal characteristics and online behaviors are at high-risk of developing AIA that may compound different psychological symptoms associated with AIA. Spending excessive time online is not in itself a defining symptom of AIA. More attention is needed on adolescent excessive weekend internet-use in prevention of potential internet addicts.http://deepblue.lib.umich.edu/bitstream/2027.42/112717/1/12889_2012_Article_4938.pd

Endoscopic variceal ligation combined with sclerotherapy for management of gastroesophageal variceal bleeding in pediatric patients: a single-center retrospective study

ObjectivesPortal hypertension (PH) frequently gives rise to severe and life-threatening complications, including hemorrhage accompanied by the rupture of esophageal and gastric varices. In contrast to the guidelines for the management of PH in adults, the optimal endoscopic management of variceal bleeding for secondary prophylaxis in children remains unclear. The present study evaluated the efficacy and safety of endoscopic variceal ligation (EVL) and endoscopic sclerotherapy (EST) to control gastroesophageal variceal bleeding in children.MethodsThis retrospective study included children with gastroesophageal variceal bleeding who underwent EST or EVL at Xinhua Hospital, Shanghai Jiaotong University School of Medicine, between February 2013 and March 2020. Short-term hemostasis rate and long-term rebleeding rate were evaluated. Adverse events related to the procedures, such as esophageal ulcer, esophageal stricture, abnormal embolization, pneumonia and perforation, were also recorded.ResultsEVL (n = 8) and EST (n = 13) were performed successfully in all pediatric patients diagnosed with moderate to severe esophageal varices concurrent with gastric varices. Hemostasis was achieved during episodes of upper gastrointestinal bleeding. The mean volume of each single aliquot of cyanoacrylate injected was 0.3 ± 0.1 ml (range: 0.1–0.5 ml). Varices were eradicated in six (75%) of the eight patients who underwent EVL after a median 2 (range: 1–4) procedures and a median time of 3.40 months (range: 1.10–13.33 months). Eleven (52.4%) of the 21 patients developed rebleeding events, with the mean duration of hemostasis being 11.1 ± 11.6 months (range 1.0–39.2 months). No treatment-related complications, for example, distal embolism, occurred except for abdominal pain in one patient (4.8%).ConclusionsEST, alone or in combination with EVL, is an effective and safe method of managing gastroesophageal variceal hemorrhage in children undergoing secondary prophylaxis