A New Paradigm to Half-Metallicity in Graphene Nanoribbons

In contrast to the well-recognized transverse-electric-field-induced half-metallicity in zigzag graphene nanoribbons, here, we demonstrate by first-principles calculations that zigzag graphene nanoribbons sandwiched between hexagonal boron nitride nanoribbons or sheets can be tuned into half-metal simply by a bias voltage or a moderate compressive strain. The half-metallicity is attributed to an enhanced coupling effect of spontaneous polarization and asymmetrical exchange correlation along the ribbon width. The findings should open a viable route for efficient spin-resolved band engineering in graphene-based devices that are compatible with the current technology of the semiconductor industry

Two-Dimensional Hexagonal Beryllium Sulfide Crystal

We report a new two-dimensional hexagonal beryllium sulfide (h-BeS) sheet with exceptional properties by extensive first-principles calculations. The h-BeS sheet presents an indirect energy gap of 4.26 eV and an outstanding thermodynamic stability up to 1000 K. Armchair-edged nanoribbons of h-BeS are wide-energy-gap semiconductors with a giant Stark effect, while the zigzag-edged ones are metals with spin glass state. Especially, the ferromagnetic zigzag nanoribbons exhibit a net magnetic moment of nearly 1.15 μ_B. These interesting electronic and magnetic properties suggest the promise of the h-BeS crystal for potential applications and should inspire experimental enthusiasm

DataSheet1_Can participation in cooperatives promote the adoption of green production techniques by Chinese apple growers: Counterfactual estimation based on propensity score matching.docx

As one of the key links of agricultural green sustainable development, it is an effective path to popularize green production technology and promote farmers’ adoption of green production technology by using cooperatives as an organizational vehicle. Based on the survey of 314 apple farmers in Shaanxi and Gansu provinces, the degree of adoption of green production technology was measured by the coefficient of variation method. At the same time, in view of the selection bias of farmers’ participation in cooperatives, the propensity score matching method was used to evaluate the influence of farmers’ participation in cooperatives on the adoption of green production techniques. The results showed that participation in cooperatives increases the probability of farmers adopting green production techniques from 25.29% to 30.29%, indicating that cooperatives increase the degree to which farmers adopt green production techniques. In addition, increased cognition of green production, which increases the price and net profit of products sold and reduces expectations of green production risks, is the primary channel through which cooperatives lead farmers to adopt green production technologies. Participation in cooperatives, though, increased input costs for apple production. In order to strengthen the active role of cooperatives in the popularization of green production technologies, more support should be given to cooperatives, and emphasis should be placed on strengthening their institutional development so that they can be standardized and developed at a high quality.</p

Nucleotide Selectivity at a Preinsertion Checkpoint of T7 RNA Polymerase Transcription Elongation

Nucleotide selection is crucial for transcription fidelity control, in particular, for viral T7 RNA polymerase (RNAP) lack of proofreading activity. It has been recognized that multiple kinetic checkpoints exist prior to full nucleotide incorporation. In this work, we implemented intensive atomistic molecular dynamics (MD) simulations to quantify how strong the nucleotide selection is at the initial checkpoint of an elongation cycle of T7 RNAP. The incoming nucleotides bind into a preinsertion site where a critical tyrosine residue locates nearby to assist the nucleotide selection. We calculated the relative binding free energy between a noncognate nucleotide and a cognate one at a preinsertion configuration via alchemical simulations, showing that a small selection free energy or the binding free energy difference (∼3 <i>k</i>_B<i>T</i>) exists between the two nucleotides. Indeed, another preinsertion configuration favored by the noncognate nucleotides was identified, which appears to be off path for further nucleotide insertion and additionally assists the nucleotide selection. By chemical master equation (CME) approach, we show that the small selection free energy at the preinsertion site along with the off-path noncognate nucleotide filtering can help substantially to reduce the error rate and to maintain the elongation rate high in the T7 RNAP transcription

Imaging Metastable States and Transitions in Proteins by Trajectory Map

It has been a long-standing and intriguing issue to develop robust methods to identify metastable states and interstate transitions from simulations or experimental data to understand the functional conformational changes of proteins. It is usually hard to define the complicated boundaries of the states in the conformational space using most of the existing methods, and they often lead to parameter-sensitive results. Here, we present a new approach, visualized Trajectory Map (vTM), to identify the metastable states and the rare interstate transitions, by considering both the conformational similarity and the temporal successiveness of conformations. The vTM is able to give a nonambiguous description of slow dynamics. The case study of a β-hairpin peptide shows that the vTM can reveal the states and transitions from all-atom MD trajectory data even when a single observable (i.e, one-dimensional reaction coordinate) is used. We also use the vTM to refine the folding/unfolding mechanism of HP35 in explicit water by analyzing a 125 μs all-atom MD trajectory and obtain folding/unfolding rates of about 1/μs, which are in good agreement with the experimental values

Additional file 1: Figure S1. of Activation of protein kinase A in the amygdala modulates anxiety-like behaviors in social defeat exposed mice

Social defeat paradigm. (TIF 442 kb

A Concise Approach to Site-Specific Topological Protein–Poly(amino acid) Conjugates Enabled by <i>in Situ</i>-Generated Functionalities

Controlling the topology of polymer-modified proteins has attracted growing interest. However, one of the main challenges in this field is the lack of efficient and site-specific methods for installing multiple bioorthogonal functionalities on substrate polymers. We report here an orchestrating strategy that provides easy access to various topological protein–poly­(amino acid) (PAA) conjugates in high yields. This method features the <i>in situ</i> installation of two “chemical handles”, including a thioester for native chemical ligation and a polyglycine nucleophile for sortase A-mediated ligation, at both ends of substrate PAAs. As a result, neither pre-functionalization of initiator or monomer units, nor post-polymerization modification of the resultant polymers, is necessary. Site-specific topological conjugates, particularly circular conjugates, can be conveniently synthesized under mild conditions from the functionalized PAAs. The biomedical utility of our method is demonstrated by the rapid and efficient generation of several therapeutic interferon-α conjugates, which exhibit significantly enhanced protease resistance and thermostability. Given the versatility of both PAAs and proteins, the method offers a convenient approach to producing libraries of conjugates for biological applications

Effects of estrous cycle on basal paw withdrawal threshould (PWT) to mechanical stimulation and tail-flick latency (TFL) to radiant heat stimulation.

<p>(A) PWTs of both hindpaws. (B) TFLs of proximal and distal. P, proestrus stage; E, Estrus stage; M, metaestrus stage; D, diestrus stage.</p

Effects of OVX on depressive-like behaviors and spatial ability.

<p>(A & B) OVX rats displayed significantly more immobility (A) and less activity (B) time in FST. Subcutaneous injection of E2 (30 μg/day for 7 days) significantly attenuated immobility and prolonged activity time. * p<0.05, ** p<0.01. (C & D) OVX rats displayed fewer crossing (C) and rearing (D) numbers in OFT. E2 replacement increased crossing and rearing numbers in OFT. * p<0.05, ** p<0.01. E2 and vehicle were injected from the 4^th week after OVX, and behavioral tests were performed at the 5^th week. (E) Showing animal's escape latencies to find the submerged platform. Cutoff time was 60 s. (F) Showing animal's swimming speed in the training and testing trials. Morris water maze training consists of two training sessions of six trials each with a 30-min resting period between the two sessions. Memory retention was tested 24 h after training. The retention values are calculated as the mean of three-trial retention test. (G) Animal's escape latencies to find the visible platform. The platform was raised above the turbid liquid surface to be visible. FST, OFT and Morris water maze tests were performed at the 5^th week after OVX or sham-OVX surgery.</p

OVX suppressed F-CPA but did not affect S-CPA.

<p>(A & B) Effects of OVX on formalin-induced CPA (F-CPA), as indicated by time spent in the treatment (formalin or normal saline)-paired compartment on preconditioning and postconditioning days (A) and CPA scores (the time spent in the treatment-paired compartment on the pre-conditioning day minus that on the post-conditioning day (B). (C & D) Effects of OVX on foot shock-induced CPA (S-CPA), as indicated by time spent in foot shock-paired compartment on preconditioning and postconditioning days (C) and CPA scores (D). ** p<0.01 versus preconditioning day. ^# p<0.05, ^## p<0.01.</p