Controlling the gelation temperature of biomimetic polyisocyanides

The gelation temperature and mechanical properties of aqueous ethylene glycol-decorated polyisocyanide solutions strongly depends on the length of the glycol tail. Copolymerisation of monomers with different tail lengths allows for precise engineering of the gel properties.     

Ice Melting to Release Reactants in Solution Syntheses

Aqueous solution syntheses are mostly based on mixing two solutions with different reactants. It is shown that freezing one solution and melting it in another solution provides a new interesting strategy to mix chemicals and to significantly change the reaction kinetics and thermodynamics. For example, a precursor solution containing a certain concentration of AgNO₃ was frozen and dropped into a reductive NaBH₄ solution at about 0 °C. The ultra‐slow release of reactants was successfully achieved. An ice‐melting process can be used to synthesize atomically dispersed metals, including cobalt, nickel, copper, rhodium, ruthenium, palladium, silver, osmium, iridium, platinum, and gold, which can be easily extended to other solution syntheses (such as precipitation, hydrolysis, and displacement reactions) and provide a generalized method to redesign the interphase reaction kinetics and ion diffusion in wet chemistry.     

Adsorption equilibrium,kinetics and mechanism of Pb(II) over carbon–silica composite biosorbent with designed surface oxygen groups

Research on Chemical Intermediates - Heavy metal contamination, especially contamination involving Pb(II), is a major environmental problem faced by modern society; hence, research on...     

一种基于PN训练序列的OFDM时频同步算法

提出了一种基于PN训练序列的OFDM时频同步的新算法.该算法通过构造一种倒序结构的同步训练序列,获得了较好的定时性能;同时利用该序列实现了较精确的频率同步.仿真结果表明,在信噪比为20 dB时,高斯信道条件下的频偏估计方差可达10-7,多径信道下可达10-5,频偏估计范围可以达到整个信号带宽的一半.与传统算法相比, 该算法符号定时更精确,频率同步性更好,具有较好的可行性和实用性.     

Whitham Hierarchy and Generalized Picard–Fuchs Operators in the N=2 Susy Yang–Mills Theory for Classical Gauge Groups

Theoretical and Mathematical Physics - We derive infinitely many meromorphic differentials based on the fractional powers of the superpotential arising from hyperelliptic curves. We obtain various...     

Multifusion-induced wall-super-thick giant multilamellar vesicles

A polymeric multivesicular system was created by hydrating a film. This system underwent multifusion events and eventually evolved into giant multilamellar vesicles with extremely thick walls. The semi-permeable wall and large size make these vesicles suitable for encapsulating living cells.     

Estimation and model selection in a class of semiparametric models for cluster data

Stimulated by a study in Bangladesh about the first birth interval, we propose a semivarying-coefficient model for cluster data analysis. We consider the estimation procedure for the proposed model and establish the asymptotic results of the proposed estimators. Furthermore, we employ the cross-validation (CV) to identify the constant coefficients. The associated asymptotic properties are rigorously examined. Simulation studies are conducted to investigate the performance of the proposed estimation and the CV-based model selection procedure for finite sample size. Finally, our methods are used to analyse the aforementioned data set to explore how several factors affect the first birth interval in Bangladesh.     

Inhibition of lethal endotoxin shock with an L-pyridylalanine containing metalloproteinase inhibitor selected by high-throughput screening of a new peptide library

Gelatinase B/MMP-9 fulfills crucial regulator or effector functions in disease states and may be pharmacologically targeted by specific inhibitors. The characteristics of cleavages of a natural gelatinase B substrate were simulated and amino acids with zinc-ion chelating side-groups were employed to design a library of peptide-based inhibitors. Here, we extend previous findings of combinatorial chemical synthesis and subsequent library deconvolution with a recently established high-throughput technology. This enabled us to study MMP inhibitors with two zinc-binding groups and to identify a new L-pyridylalanine-containing gelatinase B inhibitor. The peptide analog was found to inhibit, almost to the same degree, the neutrophil enzymes collagenase 2/ MMP-8 and MMP-9 and the monocytic tumor necrosis factor-alpha (TNF-alpha) converting enzyme (TACE/ADAM-17) in vitro and to protect mice against lethal endotoxinemia in vivo. These data illustrate the usefulness of the screening platform for protective inhibitor discovery and complement recent insights in the pathogenesis and treatment of shock syndromes.     

Air-initiated hydrosilylation of unactivated alkynes and alkenes and dehalogenation of halohydrocarbons by tris(trimethylsilyl)silane under solvent-free conditions

A highly efficient air-initiated hydrosilylation of unactivated alkynes and alkenes and dehalogenation of halohydrocarbons with tris(trimethylsilyl)silane ((TMS)₃SiH) as a reducing agent has been established under solvent-free conditions. These observations demonstrate that the potential and versatility of air to function as a competent initiator for Si-H bond activations. It can rival organic initiators and metal catalysts in its efficiency and is a superior initiating system from economic, environmentally sound and practical perspectives.     

Review of online coupling of sample preparation techniques with liquid chromatography

Sample preparation is still considered as the bottleneck of the whole analytical procedure, and efforts has been conducted towards the automation, improvement of sensitivity and accuracy, and low comsuption of organic solvents. Development of online sample preparation techniques (SP) coupled with liquid chromatography (LC) is a promising way to achieve these goals, which has attracted great attention. This article reviews the recent advances on the online SP-LC techniques. Various online SP techniques have been described and summarized, including solid-phase-based extraction, liquid-phase-based extraction assisted with membrane, microwave assisted extraction, ultrasonic assisted extraction, accelerated solvent extraction and supercritical fluids extraction. Specially, the coupling approaches of online SP-LC systems and the corresponding interfaces have been discussed and reviewed in detail, such as online injector, autosampler combined with transport unit, desorption chamber and column switching. Typical applications of the online SP-LC techniques have been summarized. Then the problems and expected trends in this field are attempted to be discussed and proposed in order to encourage the further development of online SP-LC techniques.