High-resolution and high-accuracy topographic and transcriptional maps of the nucleosome barrier.

Nucleosomes represent mechanical and energetic barriers that RNA Polymerase II (Pol II) must overcome during transcription. A high-resolution description of the barrier topography, its modulation by epigenetic modifications, and their effects on Pol II nucleosome crossing dynamics, is still missing. Here, we obtain topographic and transcriptional (Pol II residence time) maps of canonical, H2A.Z, and monoubiquitinated H2B (uH2B) nucleosomes at near base-pair resolution and accuracy. Pol II crossing dynamics are complex, displaying pauses at specific loci, backtracking, and nucleosome hopping between wrapped states. While H2A.Z widens the barrier, uH2B heightens it, and both modifications greatly lengthen Pol II crossing time. Using the dwell times of Pol II at each nucleosomal position we extract the energetics of the barrier. The orthogonal barrier modifications of H2A.Z and uH2B, and their effects on Pol II dynamics rationalize their observed enrichment in +1 nucleosomes and suggest a mechanism for selective control of gene expression

An Anti-attack Model Based on Complex Network Theory in P2P networks

Complex network theory is a useful way to study many real systems. In this paper, an anti-attack model based on complex network theory is introduced. The mechanism of this model is based on dynamic compensation process and reverse percolation process in P2P networks. The main purpose of the paper is: (i) a dynamic compensation process can turn an attacked P2P network into a power-law (PL) network with exponential cutoff; (ii) a local healing process can restore the maximum degree of peers in an attacked P2P network to a normal level; (iii) a restoring process based on reverse percolation theory connects the fragmentary peers of an attacked P2P network together into a giant connected component. In this way, the model based on complex network theory can be effectively utilized for anti-attack and protection purposes in P2P networks.Comment: arXiv admin note: excessive text overlap with arXiv:cond-mat/0504185, without attributio

Psychometric Properties and Factor Structure of the Chinese Version of the Hospital Anxiety and Depression Scale in People Living With HIV

The population of people living with HIV (PLWH) is growing in number and usually results in mental health problems that impact their quality of life. Therefore, valid instruments and screening methods for psychological disorders are of great significance. The Hospital Anxiety and Depression Scale (HADS) reveals good psychometric properties, but shows ambiguous results in factor structure. This study aims to evaluate psychometric properties in terms of the internal reliability and structure validity of the Chinese version of the HADS (C-HADS) in a large sample of PLWH in China. The C-HADS was administered to 4,102 HIV-infected adults at an HIV clinic in China. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were performed to examine the factor structure. Measurement invariance was assessed across gender and course of infection. Internal reliability was also assessed. A bifactor model with anomalous loadings of items 7, 8, and 10 fits the data best and holds measurement invariance across gender and course of infection. Internal reliability was good with all Cronbach’s alphas > 0.70 and Spearman’s ρ between 0.30 and 0.70. The C-HADS has good psychometric properties in terms of internal reliability and structure validity of a bifactor model. The C-HADS is recommended to be used as a total scale that measures general psychological distress, instead of anxiety and depression separately, when applied to PLWH. Further studies are needed to evaluate criterion validity, the cutoff score, and the effect of wording and scoring of the HADS

The Double Burdens of Mental Health Among AIDS Patients With Fully Successful Immune Restoration: A Cross-Sectional Study of Anxiety and Depression in China

Background: Anxiety and depression continue to be significant comorbidities for people with HIV infection. We investigated the prevalence of and factors associated with anxiety and depression among adult HIV-infected patients across China.Methods: In this cross-sectional study, we described clinical and psychosocial variables related to depression and anxiety in 4103 HIV-infected persons. Doctors assessed anxiety and depression by asking patients whether they had experienced anxiety or depression in the prior month. Patients also self-administered the Hospital Anxiety and Depression (HAD) scale; those with score ≥8 on HAD-A/D were considered to be at high risk of anxiety or depression.Results: Associations between socio-demographic, psychosocial, and ART-related clinical factors and risk of depression or anxiety were investigated using multivariable logistic regression. Among patients assessed between 9/2014 and 11/2015, 27.4% had symptoms of anxiety, 32.9% had symptoms of depression, and 19.0% had both. Recentness of HIV diagnoses (P = 0.046) was associated with elevated odds of anxiety. Older age (P = 0.004), higher educational attainment (P < 0.001), employment (P = 0.001), support from family / friends (P < 0.001), and sleep disturbance (P < 0.001), and number of ART regimen switches (P = 0.046) were associated with risk of depression, while neither sex nor transmission route showed any associations. There were no significant associations with HIV-specific clinical factors including current CD4+ T cell count and current viral load.Conclusions: Prevalence of symptoms of anxiety and depression is high in this cohort of treatment-experienced HIV patients. Psychological and social-demographic factors, rather than HIV disease status, were associated with risk of depression and anxiety. This finding highlights the need to deliver interventions to address the mental health issues affecting HIV-infected persons with fully successful immune restoration across China

Feedback-Controlled Topological Reconfiguration of Molecular Assemblies for Programming Supramolecular Structures

In biology, nonequilibrium assembly is characterized by fuel-driven switching between associating and nonassociating states of biomolecules. This dynamic assembly model has been used routinely to describe the nonequilibrium processes in synthetic systems. Here, we present a G-quartet-based nonequilibrium system mediated by fuel-driven co-assembly of guanosine 5’-monophosphate disodium salt hydrate and urease. Addition of lanthanum(III) ions to the system caused macroscopic dynamic switching between precipitates and hydrogels. Interestingly, combined analyses of the nonequilibrium systems demonstrated that molecules could switch between two distinct associating states without undergoing a nonassociating state, suggesting a nonequilibrium assembly mechanism of topological reconfiguration of molecular assemblies. We detailed quantitatively the nonequilibrium assembly mechanism to precisely control the phase behaviors of the active materials and, therefore, were able to apply the materials for transient-gel-templated polymerization and transient circuit connection. This work presents a new nonequilibrium system with unusual phase behavior, and the resultant active hydrogels hold substantial promise in applications including fluid confinements and transient electronics

Combining Krafft Point and Volume Phase Transition Temperature Toward Regulation of Solar Radiation and Privacy Protection

Abstract Everlasting pursuit of high energy efficiency as well as meeting fluctuant temperatures raise various lighting requirements, which is driving the originality of thermochromic smart windows (SWs). SWs with dual‐temperature response upon rational designs are identified as an effective approach to regulate solar radiation and protect privacy. Here, combining the Krafft point (Tk) of ionic surfactants and the volume phase transition temperature (VPTT) of gels toward SW materials is utilized to achieve a transition of opacity‐transparence‐opacity as temperature change, maintaining transparency at an intermediate temperature range with favorable optical modulation parameters. Cationic surfactant, hexadecylpyridinium bromide (HPB), and poly(N‐isopropylacrylamide) (PNIPAM) are combined using Tk and VPTT to serve as the dual thermo‐responsive switches for regulating solar radiation and protecting privacy. Tk of HPB can be adjusted by adding salts and VPTT is turned by introducing hydrophilic and hydrophobic comonomer. This work provides a realizable pathway by which in situ adjustable parameters may be performed and operated in external environment conditions, completely changing the smart window materials

Room-Temperature Super Hydrogel as Dye Adsorption Agent

Supramolecular hydrogels were prepared in the mixtures of a chiral amphiphilic lithocholic acid (LCA) and a nonionic surfactant, dodecyldimethylamine oxide (C₁₂DMAO), in water. With the addition of LCA to C₁₂DMAO micellar solutions, a transition from micelles to gels occurs at room temperature. Hydrogels can form at very low concentrations (below 0.1 wt %), exhibiting a super gelation capability. The rheological measurements show a strong mechanical strength with an elastic modulus exceeding 5000 Pa and a yield stress exceeding 100 Pa. Microstructures determined by TEM, SEM, and AFM observations demonstrate that the gels are formed by intertwined helical fibrils. The formation of fibrils is induced by enormous cycles of units composed of two LCA molecules and four C₁₂DMAO molecules driven by comprehensive noncovalent interaction, especially the hydrogen bonds produced in two reversed LCA molecules and the C₁₂DMAOH⁺–C₁₂DMAO pairs. The xerogels show excellent adsorption capability of the toxic dye with a maximum adsorption value of 202 mg·g^–1