Quantum solid phase and Coulomb drag in two-dimensional electron-electron bilayers of MoS2

Coulomb drag experiments can give us information about the interaction state of double-layer systems. Here, we demonstrate anomalous Coulomb drag behaviours in a two-dimensional electron-electron bilayer system constructed by stacking atomically thin MoS2 on opposite sides of thin dielectric layers of boron nitride. In the low temperature regime, the measured drag resistance does not follow the behaviour predicted by the Coulomb drag models of exchanging momenta and energies with the particles in Fermi-liquid bilayer systems. Instead, it shows an upturn to higher and higher values. We investigate quantum solid/fluid phases and the Kosterlitz-Thouless/Wigner two-dimensional quantum melting transition in this bilayer system and describe this interesting phenomenon based on thermally activated carriers of quantum defects from the formation of the correlation-induced electron solid phases with enhanced stabilization by the potential due to the boron nitride dielectric layers.Comment: published in Advanced Electronic Material

Start Learning Chinese Words Fast: An Introduction

In order to cater to the needs of Chinese language lovers, 28 basic strokes of Chinese words are firstly introduced. It is pointed out that the difficulty for foreigners to learn Chinese words is their grotesque shapes written by brush (soft) pen and printed in books. The special writing method with a hard pen and 8 directions moving steps are invented and firstly shown, which is easy for foreigners to try. The size (length) of strokes will guide them to control the proportion of a word. It could be changed according to paper size and how large they want to write. Secondly, 48 common fragments derived from 28 basic strokes are listed and the writing method described. It could help foreigners to separate and re-write unknown Chinese words and even guess out the meanings. Lastly, many characteristics or regularities of Chinese words will have great attraction for foreign language learners. Some Chinese cultures or amusing stories are also exposed in fragments and example words

Molecular cloning and function of two tumor necrosis factor receptor-associated factors genes (TRAF2 and TRAF4) from Pinctada fucata martensii

Tumor necrosis factor receptor-associated factors (TRAFs) have been studied in a few mollusks and participate in various biological processes, like apoptosis, immune response, stress, and inflammatory response. However, TRAFs’ function and mechanism of pearl oysters (Pinctada fucata martensii) are still unclear. In this study, the novel PmTRAF2 and PmTRAF4 from P. f. martensii were cloned by rapid amplification of complementary DNA ends and their mRNA expression were analyzed by quantitative real-time PCR (qPCR). The interacting protein of PmTRAF2 was verified by the yeast two-hybrid assay. The result shows that full-length of PmTRAF2 and PmTRAF4 cDNA were 2055 bp and 2365 bp, respectively. The deduced PmTRAF2 and PmTRAF4 proteins contain TRAF-type zinc finger domain and MATH domain, while PmTRAF4 lacks a RING finger domain. Multiple sequence alignment revealed that PmTRAF2 and PmTRAF4 had high homology with the ortholog of other species. Phylogenic analysis indicated that PmTRAF4 clustered with the homolog protein of Mytilus edulis and Mytilus galloprovincialis, and PmTRAF2 has the closest genetic relationship to Crassostrea gigas TRAF2. The qPCR analysis revealed that PmTRAF2 and PmTRAF4 were expressed in all six tissues, and both of them were significantly expressed in hepatopancreas and gill (p < 0.01). Under lipopolysaccharide (LPS) stimulation, polyinosinic acid (PolyI:C) stimulation, and nucleus insertion surgery, the transcripts of PmTRAF2, PmTRAF3, PmTRAF4 and PmTRAF6 in hepatopancreas were markedly changed at corresponding time points. These results have indicated that these genes may play a role in P. f. martensii innate immunity. Yeast two-hybrid assays show that PmTRAF2 interacts with PmTRAF6 but not PmTRAF3, potentially affecting downstream immune signaling pathways. Our findings provide new perspectives for further investigation of TRAFs’ immune mechanisms in bivalves

Intrinsic nonlinear Hall effect and gate-switchable Berry curvature sliding in twisted bilayer graphene

Though the observation of quantum anomalous Hall effect and nonlocal transport response reveals nontrivial band topology governed by the Berry curvature in twisted bilayer graphene, some recent works reported nonlinear Hall signals in graphene superlattices which are caused by the extrinsic disorder scattering rather than the intrinsic Berry curvature dipole moment. In this work, we report a Berry curvature dipole induced intrinsic nonlinear Hall effect in high-quality twisted bilayer graphene devices. We also find that the application of the displacement field substantially changes the direction and amplitude of the nonlinear Hall voltages, as a result of a field-induced sliding of the Berry curvature hotspots. Our work not only proves that the Berry curvature dipole could play a dominant role in generating the intrinsic nonlinear Hall signal in graphene superlattices with low disorder densities, but also demonstrates twisted bilayer graphene to be a sensitive and fine-tunable platform for second harmonic generation and rectification

Large genomic fragment deletion and functional gene cassette knock-in via Cas9 protein mediated genome editing in one-cell rodent embryos

The CRISPR-Cas RNA-guided system has versatile uses in many organisms and allows modification of multiple target sites simultaneously. Generating novel genetically modified mouse and rat models is one valuable application of this system. Through the injection of Cas9 protein instead of mRNA into embryos, we observed fewer off-target effects of Cas9 and increased point mutation knock-in efficiency. Large genomic DNA fragment (up to 95 kb) deletion mice were generated for in vivo study of lncRNAs and gene clusters. Site-specific insertion of a 2.7 kb CreERT2 cassette into the mouse Nfatc1 locus allowed labeling and tracing of hair follicle stem cells. In addition, we combined the Cre-Loxp system with a gene-trap strategy to insert a GFP reporter in the reverse orientation into the rat Lgr5 locus, which was later inverted by Cre-mediated recombination, yielding a conditional knockout/reporter strategy suitable for mosaic mutation analysis

Pressured HIV testing "in the name of love": a mixed methods analysis of pressured HIV testing among men who have sex with men in China.

INTRODUCTION: HIV testing has rapidly expanded into diverse, decentralized settings. While increasing accessibility to HIV testing is beneficial, it may lead to unintended consequences such as being pressured to test. We examined the frequency, correlates and contexts of pressured HIV testing among Chinese men who have sex with men (MSM) using mixed methods. METHODS: We conducted an online survey of MSM (N = 1044) in May 2017. Pressured HIV testing was defined as being forced to test for HIV. We conducted logistic regression analysis to determine the associations between pressured HIV testing and socio-demographic and sexual behavioural factors. Follow-up interviews (n = 17) were conducted with men who reported pressured testing and we analysed qualitative data using a thematic analysis approach. RESULTS: Ninety-six men (9.2%) reported experiencing pressure to test for HIV. Regular male sex partners were the most common source of pressure (61%, 59/96), and the most common form of pressure was a threat to end a relationship with the one who was being pressured (39%, 37/96). We found a higher risk of pressured testing in men who had only used HIV self-testing compared to men who had never self-tested (AOR 2.39 (95%CI: 1.38 to 4.14)). However, this relationship was only significant among men with low education (AOR 5.88 (95% CI: 1.92 to 17.99)) and not among men with high education (AOR 1.62 (95% CI: 0.85 to 3.10)). After pressured testing, about half of men subsequently tested for HIV (55%, 53/96) without pressure - none reported being diagnosed with HIV. Consistent with this finding, qualitative data suggest that perceptions of pressure existed on a continuum and depended on the relationship status of the one who pressured them. Although being pressured to test was accompanied by negative feelings, men who were pressured into testing often changed their attitude towards HIV testing, testing behaviours, sexual behaviours and relationship with the one who pressured them to test. CONCLUSION: Pressured HIV testing was reported among Chinese MSM, especially from men with low education levels and men who received HIV self-testing. However, in some circumstances, pressure to test helped MSM in several ways, challenging our understanding of the role of agency in the setting of HIV testing

Sodium-Glucose Cotransporter 2 Inhibitors and the Risk of Pneumonia and Septic Shock

CONTEXT: Individuals with type 2 diabetes mellitus (DM) have an increased risk of pneumonia and septic shock. Traditional glucose-lowering drugs have recently been found to be associated with a higher risk of infections. It remains unclear whether sodium-glucose cotransporter 2 inhibitors (SGLT2is), which have pleiotropic/anti-inflammatory effects, may reduce the risk of pneumonia and septic shock in DM. METHODS: MEDLINE, Embase, and ClinicalTrials.gov were searched from inception up to May 19, 2022, for randomized, placebo-controlled trials of SGLT2i that included patients with DM and reported outcomes of interest (pneumonia and/or septic shock). Study selection, data extraction, and quality assessment (using the Cochrane Risk of Bias Assessment Tool) were conducted by independent authors. A fixed-effects model was used to pool the relative risk (RRs) and 95% CI across trials. RESULTS: Out of 4568 citations, 26 trials with a total of 59 264 patients (1.9% developed pneumonia and 0.2% developed septic shock) were included. Compared with placebo, SGLT2is significantly reduced the risk of pneumonia (pooled RR 0.87, 95% CI 0.78-0.98) and septic shock (pooled RR 0.65, 95% CI 0.44-0.95). There was no significant heterogeneity of effect size among trials. Subgroup analyses according to the type of SGLT2i used, baseline comorbidities, glycemic control, duration of DM, and trial follow-up showed consistent results without evidence of significant treatment-by-subgroup heterogeneity (all P(heterogeneity) > .10). CONCLUSION: Among DM patients, SGLT2is reduced the risk of pneumonia and septic shock compared with placebo. Our findings should be viewed as hypothesis generating, with concepts requiring validation in future studies