Search

Liangjiecheng Huang, Weiqiang Li, Zikai Xu, Hongli Sun, Danfeng Ai, Yinfeng Hu, Shiqi Wang, Yu Li, Yanyan Zhou Department of Psychology, Ningbo University, Ningbo, Zhejiang, People’s Republic of ChinaCorrespondence: Yu Li; Yanyan Zhou, Department of Psychology, Ningbo University, No. 616 Fenghua Road, Ningbo, Zhejiang, 315211, People’s Republic of China, Email liyu@nbu.edu.cn; zhouyanyan@nbu.edu.cnBackground: Bystander intervention can protect victims from harm in cyberbullying. Previous studies have found that the severity of cyberbullying incidents is one of the important factors affecting decisions to intervene. However, little is known about the mediating and moderating mechanisms underlying this effect.Purpose: The current study explored the effect of the severity of cyberbullying incidents on bystander intention to intervene on social network sites (SNSs) among college students (Experiment 1), the mediating role of feelings of responsibility (Experiment 2) and the moderating role of empathy (Experiment 3).Patients and Methods: We presented cyberbullying incidents with different levels of severity through scenarios including fictive Weibo news reports and comments. Participants were exposed to a fictive cyberbullying incident and asked to complete a questionnaire including measures of the variables of interest.Results: Our results showed that the severity of incidents positively affected bystander intention to intervene through the mediation of feelings of responsibility. Empathy moderated the effect of incident severity on bystander intention to intervene.Conclusion: The results of the current study help to understand the behavior of bystanders in cyberbullying and they provide a practical reference for intervention in cyberbullying incidents.Keywords: cyberbullying, bystander, incident severity, intention to intervene, social network sites

Polymer dielectrics are preferred materials for high-energy-density capacitive energy storage. In particular, high-temperature dielectrics that can withstand harsh conditions, e.g., ≥150 °C, is of crucial importance for advanced electronics and electrical power systems. Herein, high-temperature dielectric polymer composites composed of polyetherimide (PEI) matrix and hafnium oxide (HfO2) nanoparticles are presented. It is found that the incorporation of HfO2 with a moderate dielectric constant and a wide bandgap improves the dielectric constant and simultaneously reduces the high-field leakage current density of the PEI nanocomposites. As a result, the PEI/HfO2 composites exhibit superior energy storage performance to the current high-temperature engineering polymers at elevated temperatures. Specifically, the nanocomposite with 3 vol% HfO2 displays a discharged energy density of 2.82 J/cm3 at 150 °C, which is 77% higher than neat PEI. This work demonstrates the effectiveness of incorporation of the nanofiller with a medium dielectric constant into the polymer on the improvement of high-temperature capacitive properties of the polymer composites.

The development of advanced dielectric materials with high breakdown strength, high dischargeable energy densities, and great efficiencies is imperative to meet the ever-increasing demand of modern power systems and electronic devices. Herein, we present the layer-by-layer solution prepared bilayer-structured nanocomposite films with much enhanced capacitive performance via resolving the typical paradox between dielectric constant and breakdown strength in dielectric materials. The bilayered nanocomposite films are composed of Al2O3 dispersed in polystyrene as the interfacial barrier layer to inhibit electrical conduction and the polystyrene layer with TiO2 to enhance dielectric constant. The resulting layered film exhibits a discharged energy density of 4.43 J/cm3 along with ultrahigh charge−discharge efficiencies of >90%, which is among the highest energy densities ever achieved in the polystyrene-based dielectric polymer nanocomposites. In addition, the composite films show outstanding cyclic stability under high electric fields, which would enable the long-term efficient operation of film capacitors. This contribution represents an efficient route to high-energy-density dielectric composite materials by using interfacial barrier architectures.

The introduction of inorganic components into a polymer matrix to form polymer composites is an emerging and promising approach to dielectric materials for capacitive energy storage. Ferroelectric polymers are particularly attractive as matrices for dielectric polymer composites owing to their highest dielectric constant (≥10) among the known polymers. Here, the important aspects and recent advances in the development of the ferroelectric-polymer-based dielectric polymer composites for high-energy-density capacitor applications are summarized. The preparation methods of ferroelectric-polymer composites with 0D, 1D, and 2D nanostructured fillers, surface-modified nanofillers, and hierarchically structured fillers, and their comprehensive impacts on the dielectric properties, breakdown strength, and energy density of the resulting composites are described. The most recent progress on the incorporation of multiple nanofillers with complementary functionalities into ferroelectric polymers and the design of layer-structured ferroelectric-polymer composites is also highlighted. A discussion of the scientific and technological issues that remain to be addressed and an outlook for the future of ferroelectric polymer-based dielectric composites are also presented.

Lithium enolates derived from carboxylic acids are ubiquitous intermediates in organic synthesis. Asymmetric transformations with these intermediates, a central goal of organic synthesis, are typically carried out with covalently attached chiral auxiliaries. An alternative approach is to utilize chiral reagents that form discrete, well-defined aggregates with lithium enolates, providing a chiral environment conducive of asymmetric bond formation. These reagents effectively act as noncovalent, or traceless, chiral auxiliaries. Lithium amides are an obvious choice for such reagents as they are known to form mixed aggregates with lithium enolates. We demonstrate here that mixed aggregates can effect highly enantioselective transformations of lithium enolates in several classes of reactions, most notably in transformations forming tetrasubstituted and quaternary carbon centers. Easy recovery of the chiral reagent by aqueous extraction is another practical advantage of this one-step protocol. Crystallographic, spectroscopic, and computational studies of the central reactive aggregate, which provide insight into the origins of selectivity, are also reported.

The group 11 hydride clusters [Ag6H4(dppm)4(OAc)2] (1) and [Cu3H(dppm)3(OAc)2] (2) (dppm = 1,1-bis(diphenylphosphino)methane) were synthesized in moderate yields from the reaction of M(OAc) (M = Ag, Cu) with Ph2SiH2, in the presence of dppm. Complex 1 is the first structurally characterized homometallic polyhydrido silver cluster to be isolated. Both 1 and 2 catalyze the hydrosilylation of (α,β-unsaturated) ketones. Notably, this represents the first example of hydrosilylation with an authentic silver hydride complex.

Reaction of [CuH(PPh3)]6 with 1 equiv. of Tl(OTf) results in formation of [Cu6TlH6(PPh3)6][OTf] ([1]OTf]), which can be isolated in good yields. Variable‐temperature 1H NMR spectroscopy, in combination with density functional theory (DFT) calculations, confirms the presence of a rare Tl−H orbital interaction. According to DFT, the 1H chemical shift of the Tl‐adjacent hydride ligands of [1]+ includes 7.7 ppm of deshielding due to spin‐orbit effects from the heavy Tl atom. This study provides valuable new insights into a rare class of metal hydrides, given that [1][OTf] is only the third isolable species reported to contain a Tl−H interaction. [ABSTRACT FROM AUTHOR]

Atomically precise copper nanoclusters (NCs) are of immense interest for a variety of applications, but have remained elusive. Herein, we report the isolation of a copper NC, [Cu25H22(PPh3)12]Cl (1), from the reaction of Cu(OAc) and CuCl with Ph2SiH2, in the presence of PPh3. Complex 1 has been fully characterized, including analysis by X-ray crystallography, XANES, and XPS. In the solid state, complex 1 is constructed around a Cu13 centered-icosahedron and formally features partial Cu(0) character. XANES of 1 reveals a Cu K-edge at 8979.6 eV, intermediate between the edge energies of Cu(0) and Cu(I), confirming our oxidation state assignment. This assignment is further corroborated by determination of the Auger parameter for 1, which also falls between those recorded for Cu(0) and Cu(I).

The copper hydride clusters [Cu14 H12 (phen)6(PPh3)4][X]2 (X=Cl or OTf; OTf=trifluoromethanesulfonate, phen=1,10-phenanthroline) are obtained in good yields by the reaction of [(Ph3P)CuH]6 with phen, in the presence of a halide or pseudohalide source. The complex [Cu14H12 (phen)6(PPh3)4][Cl]2 reacts with CO2 in CH2Cl2 , in the presence of excess Ph3 P, to form the formate complex [(Ph3P)2Cu(κ(2)-O2CH)], along with [(phen)(Ph3 P)CuCl].

The copper hydride clusters [Cu14 H12 (phen)6(PPh3)4][X]2 (X=Cl or OTf; OTf=trifluoromethanesulfonate, phen=1,10-phenanthroline) are obtained in good yields by the reaction of [(Ph3P)CuH]6 with phen, in the presence of a halide or pseudohalide source. The complex [Cu14H12 (phen)6(PPh3)4][Cl]2 reacts with CO2 in CH2Cl2 , in the presence of excess Ph3 P, to form the formate complex [(Ph3P)2Cu(κ(2)-O2CH)], along with [(phen)(Ph3 P)CuCl].

The reactivity of MCl3(η(1)-TEMPO) (M = Fe, 1; Al, 2; TEMPO = 2,2,6,6-tetramethylpiperidine-N-oxyl) with a variety of alcohols, including 3,4-dimethoxybenzyl alcohol, 1-phenyl-2-phenoxyethanol, and 1,2-diphenyl-2-methoxyethanol, was investigated using NMR spectroscopy and mass spectrometry. Complex 1 was effective in cleanly converting these substrates to the corresponding aldehyde or ketone. Complex 2 was also able to oxidize these substrates; however, in a few instances the products of overoxidation were also observed. Oxidation of activated alkanes, such as xanthene, by 1 or 2 suggests that the reactions proceed via an initial 1-electron concerted proton-electron transfer (CPET) event. Finally, reaction of TEMPO with FeBr3 in Et2O results in the formation of a mixture of FeBr3(η(1)-TEMPOH) (23) and [FeBr2(η(1)-TEMPOH)]2(μ-O) (24), via oxidation of the solvent, Et2O.

Chen Li,1,2 Lei Zhao,1 Qingjie Wang,1 Shao Ma,3 Jintang Sun,1 Chao Ma,1 Jia Liu,1 Xuanxuan Jing,1 Dan Ai,1 Zhaodi Nan,1 Xun Qu11Institute of Basic Medical Sciences, QiLu Hospital of Shandong University, Jinan 250012, Shandong, People’s Republic of China; 2Department of Radiation Oncology, QiLu Hospital of Shandong University, Jinan 250012, Shandong, People’s Republic of China; 3Department of Breast Surgery, QiLu Hospital of Shandong University, Jinan 250012, Shandong, People’s Republic of ChinaPurpose: One of the cardinal etiological factors for oral squamous cell carcinoma (OSCC) is Human papillomavirus (HPV). Neutrophils were potential targets of immune therapy for patients with OSCC. The objective of this study was to determine if neutrophils density and HPV status can be used to define a high-risk category of patients in OSCC and to investigate the possible relationship between them.Patients and methods: We performed immunohistochemistry to probe neutrophils infiltration and HPV (P16) expression in 81 patients with OSCC. Prognostic factors for cancer-related survival were evaluated by univariate and multivariate analyses. We used the detection of cytokines to investigate the possible molecular mechanisms between neutrophils infiltration and HPV status.Results: There were significantly higher numbers of CD15+ neutrophils infiltration in OSCC tissues. Higher numbers of CD15+ neutrophils infiltration was related to stage Ⅲ，Ⅳ (p

Due to the violent reaction potential of high explosives, in tests where a reaction is not desired, it can be safe and convenient to use an inert mock that can mimic relevant properties of the associated explosive. Use of mock materials is well-established in explosives work, but most existing mocks are generally meant to mimic only one or two properties of a given explosive, potentially failing to match the explosive in other critical ways. Recently, there has been interest in developing robust thermomechanical mocks for many common explosives. Here, eleven materials are systematically chosen and investigated as potential thermomechanical mocks for TATB, the explosive component of PBX 9502. DSC, nanoindentation, and compression testing are used to narrow down to most appropriate mocks and identify their advantages and limitations. Hardness and elastic modulus are reported for the first time for the molecular crystals iodoanthranilic acid, hexamine, melamine, and trithiolane dioxide, and the crystal structure is reported for the first time for the molecular crystals iodoanthranilic acid and iodosalicylic acid.

OBJECTIVE: The purpose of this study was to evaluate the combined efficacy of low-calorie diets and aerobic training on the nutritional status of obese patients with early type 2 diabetes mellitus. PATIENTS AND METHODS: 120 consecutive obese patients with early type 2 diabetes were admitted to our hospital between August 2021 and December 2022. The patients enrolled were equally and randomly allocated into the control group (60 cases, given conventional diabetes diet intervention) and the study group (60 cases, given a low-calorie diet intervention combined with aerobic training). The parameters, including the nutritional status, fasting insulin (FINS), Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), blood lipid level, and quality of life, were compared between the two groups. RESULTS: Before treatment, there were no measurable differences in the levels of fasting blood glucose (FBG), 2-hour postprandial blood glucose (2hPG), glycosylated hemoglobin (HbAlc), albumin (ALB), prealbumin (PA), and hemoglobin (Hb) between the two groups (p>0.05), whereas two months after treatment, the FBG, 2hPG, and HbAIc levels were greatly lower, and the levels of ALB, PA, and Hb were significantly higher in the study group than those in the control group (p<0.05). Before treatment, no statistically significant differences were found in FINS and HOMA-IR values between the two groups (p>0.05). Two months after treatment, however, the study group showed lower FINS and HOMA-IR values as compared to the control group, with statistically significant differences (p<0.05). Before treatment, there was no statistically significant difference in the levels of triacylglycerol, total cholesterol, high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) between the two groups (p>0.05), while the four levels in the study group were significantly lower than those in the control group two months after treatment (p<0.05). Similarly, there were no statistically significant differences in scores of physiological, psychological, social, and therapy-related problems between the two groups before treatment (p>0.05), whereas the abovementioned scores were evidently higher in the study group than control group two months after treatment (p<0.05). CONCLUSIONS: A low-calorie diet intervention combined with aerobic training exerted good effects in terms of greatly enhancing the nutritional status among obese patients with early type 2 diabetes mellitus, which was deemed appropriate for clinical promotion and implementation. [ABSTRACT FROM AUTHOR]