Habitat fragmentation increases the risk of local extinction of small reptiles: A case study on Phrynocephalus przewalskii.

Habitat fragmentation represents a multifaceted global conservation threat, exerting both direct and indirect effects on individual animals and communities. Reptiles, particularly smaller species with limited migratory abilities, are especially vulnerable to these changes. This study examines how small reptiles adapt their life history strategies in fragmented habitats and determines whether their responses are primarily due to phenotypic plasticity or genetic adaptation.

Semirational engineering of polyphosphate kinase for developing a cost-effective, robust, and efficient adenosine 5'-triphosphate regeneration system.

The adenosine 5'-triphosphate (ATP) regeneration system can significantly reduce the cost of many biocatalytic processes. Numerous studies have endeavored to utilize the ATP regeneration system based on PPK (PPK). However, the wild-type PPK enzyme possesses limitations such as low enzymatic activity, poor stability, and limited substrate tolerance, impeding its application in catalytic reactions.

Immobilization of Escherichia coli cells harboring a nitrilase with improved catalytic properties though polyethylenemine-induced silicification on zeolite.

In the chemical-biological synthesis route of gabapentin, immobilized Escherichia coli cells harboring nitrilase are used to catalyze the biotransformation of intermediate 1-cyanocyclohexaneacetonitile to 1-cyanocyclohexaneacetic acid. Herein, we present a novel cell immobilization method, which is based on cell adsorption using 75 g/L Escherichia coli cells and 6 g/L zeolite, cell crosslinking using 3 g/L polyethylenemine and biomimetic silicification using 18 g/L hydrolyzed tetramethylorthosilicate. The constructed "hybrid biomimetic silica particles (HBSPs)" with core-shell structure showed a specific activity of 147.

Numerical study on the influence of wall temperature gradient on aerodynamic characteristics of low aspect ratio flying wing configuration.

With the aim for a low-aspect-ratio flying wing configuration, this study explores the influence of wall temperature gradient on the laminar and turbulent boundary layers of aircraft surface and determines the effect on the transition Reynolds number and wall friction drag. A four-equation turbulence model with transition mode is used to numerically simulate the flow around the model. The variation of wall friction coefficient, transition Reynolds number, and turbulent boundary layer flow with wall temperature are emphatically investigated.

Identification of a novel promoter for driving antibiotic-resistant genes to reduce the metabolic burden during protein expression and effectively select multiple integrations in Pichia Pastoris.

Routine approaches for the efficient expression of heterogenous proteins in Pichia pastoris include using the strong methanol-regulated alcohol oxidase (AOX1) promoter and multiple inserts of expression cassettes. To screen the transformants harboring multiple integrations, antibiotic-resistant genes such as the Streptoalloteichus hindustanus bleomycin gene are constructed into expression vectors, given that higher numbers of insertions of antibiotic-resistant genes on the expression vector confer resistance to higher concentrations of the antibiotic for transformants. The antibiotic-resistant genes are normally driven by the strong constitutive translational elongation factor 1a promoter (P).

Leaching of Valuable Elements from the Waste Chromite Ore Processing Residue: A Kinetic Analysis.

The efficacious treatment and resource utilization of the chromite ore processing residue (COPR) is important for chromate salt production. In this study, the leaching of valuable elements from the waste COPR was investigated. X-ray diffraction (XRD) analysis showed that the COPR mainly contained periclase (MgCrO), magnesiochromite ((Fe, Mg) (Cr, Fe)O), Fe (Cr, Al)O, and MgFeAlO.

Integrated guidance and control for missile with narrow field-of-view strapdown seeker.

Due to the removal of the mechanically stable platform in the conventional gimbaled seeker, the strapdown seeker's measurement is coupled with the missile body attitude motion, such that the inertial line-of-sight (LOS) angular rate required to implement traditional guidance laws cannot be measured, and the field-of-view (FOV) limit must be considered when designing guidance and control systems for a strapdown homing missile. To address these practical problems, an integrated guidance and control (IGC) scheme with considering the FOV limit is proposed in this paper. A novel IGC model is first derived based on the body-LOS (BLOS) angle that a strapdown seeker can directly measure, and then an IGC controller is designed using the dynamic surface control technique.

Engineering a Pichia pastoris nitrilase whole cell catalyst through the increased nitrilase gene copy number and co-expressing of ER oxidoreductin 1.

1-Cyanocyclohexaneacetic acid (1-CHAA) is a critical intermediate for the synthesis of the antiepileptic agent gabapentin. Previously, our group has established a novel manufacturing route for 1-CHAA through bioconversion catalyzed by an Escherichia coli (E. coli) nitrilase whole cell catalyst.

Separation and purification of l-methionine from E. coli fermentation broth by macroporous resin chromatography.

Methionine is an essential sulfur-containing amino acid for organisms. The separation and purification are important for the production of l-methionine from fermentation broth. In this work, the adsorption properties for l-methionine separation of ten macroporous resins were firstly evaluated.

Optimization of positional parameters of close-formation flight for blended-wing-body configuration.

In the present study, we study formation flight with two flying wing configurations. A low speed wind tunnel test is conducted to validate the accuracy of the Computational Fluid Dynamics (CFD). Two optimization procedures are implemented at a high subsonic speed.

Highly efficient conversion of 1-cyanocycloalkaneacetonitrile using a "super nitrilase mutant".

Nitrilase is the member of carbon-nitrogen hydrogen hydrolase superfamily, which has been widely used for the hydrolysis of nitriles into corresponding carboxylic acids. But most nitrilases are plagued by product inhibition in the industrial application. In this study, a "super nitrilase mutant" of nitrilase with high activity, thermostability and improved product tolerance from Acidovorax facilis ZJB09122 was characterized.

Engineering the residues on "A" surface and C-terminal region to improve thermostability of nitrilase.

Nitrilases can hydrolyze nitriles to corresponding carboxylic acids in one single step, which have great potential as valuable biocatalysts for chemical synthesis. However, the poor thermostability of the nitrilases restrict their applications in industry. In this work, error-prone PCR and site-directed mutagenesis were utilized to improve the thermostability of nitrilases.

Design of a Molecular Hybrid of Dual Peptide Inhibitors Coupled on AuNPs for Enhanced Inhibition of Amyloid β-Protein Aggregation and Cytotoxicity.

Aggregation of amyloid-β protein (Aβ) is a pathological hallmark of Alzheimer's disease (AD), so the inhibition of Aβ aggregation is an important strategy for the prevention and treatment of AD. Herein, we proposed to design molecular hybrids of peptide inhibitors by combining two peptide inhibitors, VVIA and LPFFD, into single sequences and examined their effects on Aβ aggregation and cytotoxicity. The hybrid peptides exhibit increased but moderate inhibitory activity as compared to their two precursors.

Design of LVFFARK and LVFFARK-functionalized nanoparticles for inhibiting amyloid β-protein fibrillation and cytotoxicity.

Aggregation of amyloid β-protein (Aβ) into amyloid oligomers and fibrils is pathologically linked to Alzheimer's disease (AD). Hence, the inhibition of Aβ aggregation is essential for the prevention and treatment of AD, but the development of potent agents capable of inhibiting Aβ fibrillogenesis has posed significant challenges. Herein, we designed Ac-LVFFARK-NH2 (LK7) by incorporating two positively charged residues, R and K, into the central hydrophobic fragment of Aβ17-21 (LVFFA) and examined its inhibitory effect on Aβ42 aggregation and cytotoxicity by extensive physical, biophysical, and biological analyses.

A novel nickel-chelated surfactant for affinity-based aqueous two-phase micellar extraction of histidine-rich protein.

Aqueous two-phase micellar systems (ATPMSs) composed of nonionic surfactants are considered promising for the separation and purification of proteins. To improve the specificity of ATPMSs, a novel nickel-chelated surfactant was prepared by successive modifications of Triton X-114 (TX). Characterizations by Fourier transformation infrared spectroscopy demonstrated the successful synthesis of the nickel-chelated surfactant (TX-Ni).