Direct asymmetric synthesis of β-branched aromatic α-amino acids using engineered phenylalanine ammonia lyases.

β-Branched aromatic α-amino acids are valuable building blocks in natural products and pharmaceutically active compounds. However, their chemical or enzymatic synthesis is challenging due to the presence of two stereocenters. We design phenylalanine ammonia lyases (PAL) variants for the direct asymmetric synthesis of β-branched aromatic α-amino acids.

Encapsulation and thermal properties of composite phase change materials based on cobalt/nitrogen double-doped ZIF-67 derived carbon.

To solve the problems of easy leakage and weak thermal conductivity of single-phase change material, in this experiment, cobalt/nitrogen-doped ZIF-67 derived carbon (CoN-ZIF-C) was constructed as the carrier material, and paraffin was used as the phase change core material to construct thermally enhanced shaped composite phase change materials (P@CoN-ZIF-C). The composite PCMs were characterized using scanning electron microscopy, isothermal nitrogen adsorption-desorption, X-ray diffraction, and Fourier infrared spectroscopy, and their performance was evaluated using transient planar heat source techniques, differential scanning calorimetry, and thermal cycling tests. The results indicated that the impurities of the acid-washed porous carbon material were reduced and the loading of the paraffin was 60%, and the prepared P@CoN-ZIF-C had an excellent thermal performance.

Research progress on MOFs and their derivatives as promising and efficient electrode materials for electrocatalytic hydrogen production from water.

Hydrogen energy is considered to be the most potential "ultimate energy source" due to its high combustion calorific value, cleanliness, and pollution-free characteristics. Furthermore, the production of hydrogen the electrolysis of water has the advantages of simplicity, high efficiency, environmentally safe, and high-purity hydrogen. However, it is also associated with issues such as high-power consumption for the reaction and limited large-scale application of noble metal catalysts.

Synergistic Catalytic Performance of Toluene Degradation Based on Non-Thermal Plasma and Mn/Ce-Based Bimetal-Organic Frameworks.

A series of Mn/Ce-based bimetal-organic frameworks, recorded as MCDx (x = 1, 2, 4, 6), were prepared by a solvothermal synthesis method to explore their effects and performance in the synergistic catalysis of toluene under the irradiation of non-thermal plasma. The catalytic properties of different manganese loadings in MCDx for degradation of toluene were investigated. The microphysical structures of the material were analyzed by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA).

[Progress in the effects of warming on soil NO and CH emission and the underlying micro-bial mechanisms].

Global warming has received widespread concern. The increasing concentration of greenhouse gases (GHG) is one of the major factors contributing to global warming. Soil is a major source of GHG.

The effect of allometric partitioning on herbivory tolerance in four species in South China.

Herbivory tolerance can offset the negative effects of herbivory on plants and plays an important role in both immigration and population establishment. Biomass reallocation is an important potential mechanism of herbivory tolerance. To understand how biomass allocation affects plant herbivory tolerance, it is necessary to distinguish the biomass allocations resulting from environmental gradients or plant growth.

Clinical application of planar puncture template-assisted computed tomography-guided percutaneous biopsy for small pulmonary nodules.

Aims: The aims of this study were to evaluate the clinical application of planar puncture template (PPT) in computed tomography (CT)-guided percutaneous needle lung biopsy.

Subjects And Methods: A total of 56 patients with small pulmonary nodules who received CT-guided percutaneous lung biopsy assisted by PPT were included in the study. Five steps were included in the study: fixing position, CT scanning and designing needle pathway, installing navigation system and template, puncturing fixation needle, and performing biopsy needle insertion and biopsy.

A greater foraging scale, not a higher foraging precision, may facilitate invasion by exotic plants in nutrient-heterogeneous conditions.

Background And Aims: Soil nutrient heterogeneity has been proposed to influence competitive outcomes among different plant species. Thus, it is crucial to understand the effects of environmental heterogeneity on competition between exotic invasive and native species. However, the effects of soil nutrient heterogeneity on the competition between invasive and native plants have rarely been linked to root foraging behaviour.

Differential responses of invasive and native plants to warming with simulated changes in diurnal temperature ranges.

Although many studies have documented the effects of global warming on invasive plants, little is known about whether the effects of warming on plant invasion differ depending on the imposed change in different diurnal temperature ranges (DTR). We tested the impact of warming with DTR change on seed germination and seedling growth of eight species in the family Asteraceae. Four of these are invasive (, , var.

Detection of genioglossus myoelectric activity using ICA of multi-channel mandible sEMG.

Background: Genioglossus myoelectric activity is of great significance in evaluating clinical respiratory function. However, there is a tradeoff in genioglossus EMG measurement with respect to accuracy versus convenience.

Objective: This paper presents a way to separate the characteristics of genioglossus myoelectric activity from multi-channel mandible sEMG through independent component analysis.

Effects of climate change on plant population growth rate and community composition change.

The impacts of climate change on forest community composition are still not well known. Although directional trends in climate change and community composition change were reported in recent years, further quantitative analyses are urgently needed. Previous studies focused on measuring population growth rates in a single time period, neglecting the development of the populations.

Biodiversity of Jinggangshan Mountain: the importance of topography and geographical location in supporting higher biodiversity.

Diversity is mainly determined by climate and environment. In addition, topography is a complex factor, and the relationship between topography and biodiversity is still poorly understood. To understand the role of topography, i.

How does tree age influence damage and recovery in forests impacted by freezing rain and snow?

The response and recovery mechanisms of forests to damage from freezing rain and snow events are a key topic in forest research and management. However, the relationship between the degree of damage and tree age, i.e.

Effects of nanosized constriction on thermal transport properties of graphene.

Unlabelled: Thermal transport properties of graphene with nanosized constrictions are investigated using nonequilibrium molecular dynamics simulations. The results show that the nanosized constrictions have a significant influence on the thermal transport properties of graphene. The thermal resistance of the nanosized constrictions is on the order of 10(7) to 10(9) K/W at 150 K, which reduces the thermal conductivity by 7.

A simplified computer model of cardiovascular system with an arm branch.

Non-invasive pressure simulators that regenerate oscillometric waveforms promise an alternative to expensive clinical trials for validating oscillometric noninvasive blood pressure devices. However, existing simulators only provide oscillometric pressure in cuff and thus have a limited accuracy. It is promising to build a physical simulator that contains a synthetic arm with a built-in brachial artery and an affiliated hydraulic model of cardiovascular system.

Non-Additive effects on decomposition from mixing litter of the invasive Mikania micrantha H.B.K. with native plants.

A common hypothesis to explain the effect of litter mixing is based on the difference in litter N content between mixed species. Although many studies have shown that litter of invasive non-native plants typically has higher N content than that of native plants in the communities they invade, there has been surprisingly little study of mixing effects during plant invasions. We address this question in south China where Mikania micrantha H.

[Nitrate accumulation in vegetables and its residual in vegetable fields].

Determinations of 11 kinds, 48 varieties of vegetables were carried out at different seasons. The results showed that nitrate-N concentrations in 20 vegetables reached Pollution Level 4 (NO3(-)-N > 325 mg.kg-1), which accounted for 41.