Relationship of Leffler (Bronsted) alpha values and protein folding Phi values to position of transition-state structures on reaction coordinates

The positions of transition states along reaction coordinates (r++) for simple chemical reactions are often estimated from Leffler alpha values, the slope of plots of DeltaG++ (activation energy) versus DeltaG(0) (equilibrium free energy) for a series of structural variants. Protein folding is more complex than simple chemical reactions and has a multitude of reaction coordinates. Phi-Value analysis measures degree of structure formation at individual residues in folding transition states from the ratio DeltaDeltaG++/DeltaDeltaG(0) for mutations. alpha values are now being used to analyze protein folding by lumping series of Phi values into single plots. But, there are discrepancies in the values of alpha for folding with more classical measures of the extent of structure formation, which I rationalize here. I show for chemical reactions with just a single reaction coordinate that alpha = r++ only for limiting cases, such as for reactants and products being in parabolic energy wells of identical curvature. Otherwise, alpha can differ radically from r++, with alpha being determined just by the angles of intersection of reactant and product energy surfaces. Phi is an index of the progress of a local, energy-based reaction coordinate at the global transition state: Phi <0.5 corresponds to <50% progress of the local coordinate at the global transition state and Phi >0.5 means >50%. Protein Leffler plots can force different local indexes to a single fit and give skewed underestimates of the extent of global structure formation in transition states that differ from other measures of structure formation.     

From the Cover: Near-linear cost increase to reduce climate-change risk

One approach in climate-change policy is to set normative long-term targets first and then infer the implied emissions pathways. An important example of a normative target is to limit the global-mean temperature change to a certain maximum. In general, reported cost estimates for limiting global warming often rise rapidly, even exponentially, as the scale of emission reductions from a reference level increases. This rapid rise may suggest that more ambitious policies may be prohibitively expensive. Here, we propose a probabilistic perspective, focused on the relationship between mitigation costs and the likelihood of achieving a climate target. We investigate the qualitative, functional relationship between the likelihood of achieving a normative target and the costs of climate-change mitigation. In contrast to the example of exponentially rising costs for lowering concentration levels, we show that the mitigation costs rise proportionally to the likelihood of meeting a temperature target, across a range of concentration levels. In economic terms investing in climate mitigation to increase the probability of achieving climate targets yields “constant returns to scale,” because of a counterbalancing rapid rise in the probabilities of meeting a temperature target as concentration is lowered.     

指挥决策系统在应急医学救援中的应用现状及展望

阐述了突发事件对指挥决策的影响因素及其应对策略,比较了国内外医学救援指挥系统的发展现状,提出了基于全程救治链（WTC）指挥决策系统的“链-树”构架,指出了集成应用现代通信技术,整合多种救援资源,高效统筹现场急救、途中救治、后方医疗等各类信息,构建全程救治链指挥决策系统是未来应急医学救援的发展趋势。     

Drinking game play among first-year college student drinkers: An event-specific analysis of the risk for alcohol use and problems

Background: College students who play drinking games (DGs) more frequently report higher levels of alcohol use and experience more alcohol-related harm. However, the extent to which they are at risk for increased consumption and harm as a result of DG play on a given event after accounting for their typical DG participation, and typical and event drinking, is unclear. Objectives: We examined whether first-year students consumed more alcohol and were more likely to experience consequences on drinking occasions when they played DGs. Methods: Participants (n?=?336) completed up to six web-based surveys following weekend drinking events in their first semester. Alcohol use, DG play, and consequences were reported for the Friday and Saturday prior to each survey. Typical DG tendencies were controlled in all models. Typical and event alcohol use were controlled in models predicting risk for consequences. Results: Participants consumed more alcohol on DG versus non-DG events. All students were more likely to experience blackout drinking consequences when they played DGs. Women were more likely to experience social-interpersonal consequences when they played DGs. Conclusion: DG play is an event-specific risk factor for increased alcohol use among first-year students, regardless of individual DG play tendencies. Further, event DG play signals increased risk for blackout drinking consequences for all students, and social-interpersonal consequences for women, aside from the amount of alcohol consumed on those occasions as well as typical drinking behaviors. Prevention efforts to reduce high-risk drinking may be strengthened by highlighting both event- and person-specific risks of DG play.     

Workplace exposure to engineered nanomaterials: The Italian path for the definition of occupational health and safety policies

This study explores the way the publication of a National White Book on health and safety risks that affect workers in jobs involving Nanotechnologies and Nanomaterials influenced the key Italian stakeholders attitude toward this issue and identifies the standpoints and priorities shared among researchers and stakeholders to develop a policy framework to address this issue.     

The analysis of VH and VL genes repertoires of Fab library built from peripheral B cells of human rabies virus vaccinated donors

A human combinatorial Fab antibody library was generated from immune repertoire based on peripheral B cells of ten rabies virus vaccinated donors. The analysis of random Fab fragments from the unselected library presented some bias of V gene usage towards IGHV-genes and IGLV-gen families. The screening of the Fab library on rabies virus allowed specific human Fab antibody fragments characterized for their gene encoding sequences, binding and specificities to RV. Genetic analysis of selected Fabs indicated that the IGHV and IGLV differ from the germ-line sequence. At the level of nucleotide sequences, the IGHV and IGLV domains were found to share 74–92% and 90–96% homology with sequences encoded by the corresponding human germ-line genes respectively. IGHV domains are characterized most frequently by IGHV3 genes, and large proportions of the anti-RV heavy chain IGHV domains are obtained following a VDJ recombination process that uses IGHD3, IGHD2, IGHD1 and IGHD6 genes. IGHJ3 and IGHJ4 genes are predominantly used in RV-Fab. The IGLV domains are dominated by IGKV1, IGLV1 and IGLV3 genes. Numerous somatic hypermutations in the RV-specific IGHV are detected, but only limited amino acid replacement in most of the RV-specific IGLV particularly in those encoded by J proximal IGLV or IGKV genes are found. Furthermore, IGHV3–IGKV1, IGHV3–IGVL1, and IGHV3–IGLV3 germ-line family pairings are preferentially enriched after the screening on rabies virus.     

基于时机理论脊髓损伤患者主要照顾者照护体验的质性研究

目的基于时机理论框架探讨脊髓损伤主要照顾者在不同阶段的照护体验。方法2018年11月至2019年5月,采用目的抽样选取安徽医科大学第一附属医院脊柱外科住院及出院脊髓损伤患者的主要照顾者46名为研究对象,采用现象学研究法,基于时机理论的五个不同时期对其进行非结构访谈,以Colaizzi分析法对资料进行分析。结果按照时机理论的五个不同时期提炼主题。手术前期,害怕面对现实;手术后期,缺乏疾病相关知识;出院准备期,焦虑无助;出院调适期,主动应对,希望提高居家照护能力;出院稳定期,勇敢接受,努力应对。结论脊髓损伤照顾者的照护体验是一个复杂动态的过程,患者处于不同的疾病阶段,照顾者的照护体验与之变化,应给予每阶段针对性指导,帮助脊髓损伤家庭树立重新开始的信心。