Comprehensive analysis of the effect of rs2295080 and rs2536 polymorphisms within the mTOR gene on cancer risk.

There is still no conclusion on the potential effect of the rs2295080 and rs2536 polymorphisms of mTOR (mammalian target of rapamycin) gene on different cancers. Herein, we performed a comprehensive assessment using pooled analysis, FPRP (false-positive report probability), TSA (trial sequential analysis), and eQTL (expression quantitative trait loci) analysis. Eighteen high-quality articles from China were enrolled.

Analysing and optimizing the electrolysis efficiency of a lithium cell based on the electrochemical and multiphase model.

Based on an electrochemical multiphysical simulation, a method for analysing electrolysis efficiency has been presented that considers the energy consumption required to produce a single kilogram of lithium and for the production of lithium, rather than the voltage in various parts. By adopting them as the criteria for analysing electrolysis efficiency in the lithium cell, several structural parameters have been optimized, such as the anode radius and anode-cathode distance. These parameters strongly affect the cell voltage and the velocity field distribution, which has a significant impact on the concentration distribution.

Computational fluid dynamics simulation as a tool for optimizing the hydrodynamic performance of membrane bioreactors.

The hydrodynamic properties and shear stresses experienced by a membrane bioreactor (MBR) are directly related to its rate of membrane fouling. In this study, computational fluid dynamic models have been combined with cold model PIV experimental studies to optimize the performance properties of MBRs. The effects of membrane module height, number of aeration tubes and membrane spacing on liquid phase flow rates, gas holdup and shear stresses at the membrane surface have been investigated.

Hydrodynamic characteristics of the two-phase flow field at gas-evolving electrodes: numerical and experimental studies.

Gas-evolving vertical electrode system is a typical electrochemical industrial reactor. Gas bubbles are released from the surfaces of the anode and affect the electrolyte flow pattern and even the cell performance. In the current work, the hydrodynamics induced by the air bubbles in a cold model was experimentally and numerically investigated.

Coupled electro-thermal field in a high current electrolysis cell or liquid metal batteries.

Coupled electro-thermal field exists widely in chemical batteries and electrolysis industry. In this study, a three-dimensional numerical model, which is based on the finite-element software ANSYS, has been built to simulate the electro-thermal field in a magnesium electrolysis cell. The adjustment of the relative position of the anode and cathode can change the energy consumption of the magnesium electrolysis process significantly.

Leaching process for recovering valuable metals from the LiNiCoMnO cathode of lithium-ion batteries.

In view of the importance of environmental protection and resource recovery, recycling of spent lithium-ion batteries (LIBs) and electrode scraps generated during manufacturing processes is quite necessary. An environmentally sound leaching process for the recovery of Li, Ni, Co, and Mn from spent LiNiCoMnO-based LIBs and cathode scraps was investigated in this study. Eh-pH diagrams were used to determine suitable leaching conditions.

[Response Mechanism of Trace Metals in the Bishuiyan Subterranean River to the Rainfall and Their Source Analysis].

High-frequency sampling was conducted at the outlet of Guangxi Bishuiyan karst subterranean river using an automatic sampler during the rainfall events. The hydrochemical drymanic variation characteristics of trace metals (Cu, Pb, Zn, Cd) at the outlet of Guangxi Bishuiyan karst subterranean river were analyzed, and the sources of the trace metals in the subterranean river as well as their response to rainfall were explored. The results showed that the rainfall provoked a sharp decrease in the major elements (Ca²⁺, Mg²⁺, HCO₃⁻, etc.

[Effects of P and K fertilizer on content of coumarin and yield of Glehnia littoralis].

By a orthogonal experiment, the influence of different ratio of phosphorus and potassium fertilizers on imperatorin, isoimperatorin and psoralen contents and yield of Glehnia littoralis were studied. The results showed that root dry weight and the yield of G. littoralis increased when reasonably applied phosphorus fertilizer combined with potassium fertilizer within a certain range.

Recovery of cathode materials and Al from spent lithium-ion batteries by ultrasonic cleaning.

Cathode materials are difficult to separate from Al-foil substrates during the recycling of spent lithium-ion batteries (LIBs), because of the strong bonding force present. In this study, ultrasonic cleaning was used to separate and recycle these cathode materials. The mechanism of separation was ascribed to the dissolution of polyvinylidene fluoride (PVDF) and the cavitation caused by ultrasound.

Transformation of multi-component ginkgolide into ginkgolide B by Coprinus comatus.

Background: As the strongest antagonist of the platelet activating factor, ginkgolide B (GB) possesses anti-ischemic, anti-oxidant and anti-convulsant properties, and it is used for the treatment of thrombosis in clinical practice. Till now, GB is usually obtained from extraction of Ginkgo biloba leaves through column chromatography with an extremely low yield and high cost, which can not meet clinical requirement. Therefore, it is urgent to find a new method to prepare GB.

Comparison of Abbott and Da-an real-time PCR for quantitating serum HBV DNA.

Aim: To compare the performance of the Da-an real-time hepatitis B virus (HBV) DNA assay and Abbott RealTime HBV assay.

Methods: HBV DNA standards as well as a total of 180 clinical serum samples from patients with chronic hepatitis B were measured using the Abbott and Da-an real-time polymerase chain reaction (PCR) assays. Correlation and Bland-Altman plot analysis was used to compare the performance of the Abbott and Da-an assays.

Franck-Condon factors perturbed by damped harmonic oscillators: solvent enhanced X (1)Ag ↔ A(1)B1u absorption and fluorescence spectra of perylene.

Damped harmonic oscillators are utilized to calculate Franck-Condon factors within displaced harmonic oscillator approximation. This is practically done by scaling unperturbed Hessian matrix that represents local modes of force constants for molecule in gaseous phase, and then by diagonalizing perturbed Hessian matrix it results in direct modification of Huang-Rhys factors which represent normal modes of solute molecule perturbed by solvent environment. Scaling parameters are empirically introduced for simulating absorption and fluorescence spectra of an isolated solute molecule in solution.

Aqueous dual-tailed surfactants simulated on the alumina surface.

Atomistic molecular dynamics (MD) simulations were used to compare the morphology of aqueous surfactant self-assembled aggregates on a flat alumina substrate. The substrate was modeled using the CLAYFF force field, and it was considered fully protonated. Three ionic surfactants were considered, all with a sulfate headgroup.

A new endoscopic ultrasonography image processing method to evaluate the prognosis for pancreatic cancer treated with interstitial brachytherapy.

Aim: To develop a fuzzy classification method to score the texture features of pancreatic cancer in endoscopic ultrasonography (EUS) images and evaluate its utility in making prognosis judgments for patients with unresectable pancreatic cancer treated by EUS-guided interstitial brachytherapy.

Methods: EUS images from our retrospective database were analyzed. The regions of interest were drawn, and texture features were extracted, selected, and scored with a fuzzy classification method using a C++ program.

Theoretical studies on the mechanism of activation of phosphoprotein phosphatases and purple acid phosphatases suggest an evolutionary strategy to survive in acidic environments.

Dephosphorylation reactions of phosphoprotein phosphatases (PPPs) share a common catalytic cycle. In one stage of the cycle, the active site is regenerated through formation of a new nucleophilic μ-hydroxy moiety and reprotonation of the proton donor, His125 (numbered according to the protein phosphatase 1 sequence). To date the exact details of the mechanism of this step remain uncertain.

Theoretical studies on the reaction mechanism of PP1 and the effects of different oxidation states of the Mn-Mn center on the mechanism.

Protein phosphatase 1 (PP1) is a dinuclear metalloenzyme that catalyzes the dephosphorylation of serine and threonine residues. In this work, the catalytic reaction mechanism of PP1 was theoretically investigated by hybrid density functional theory. Firstly, an initial model of the Mn(II)-Mn(II) active site of PP1 was constructed on the basis of the high-resolution crystal structure, and stationary points along the reaction pathway were optimized and analyzed.

Theoretical study of the oxidation of phenolates by the [Cu2O2(N,N'-di-tert-butylethylenediamine)2]2+ complex.

Experiments have shown that the μ-η(2):η(2)-peroxodicopper(II) complex [Cu(2)O(2)(N,N'-di-tert-butylethylenediamine)(2)](2+) rapidly oxidizes 2,4-di-tert-butylphenolate into a mixture of catechol and quinone and that, at the extreme temperature of -120 °C, a bis-μ-oxodicopper(III)-phenolate intermediate, labeled complex A, can be observed. These experimental results suggest a new mechanism of action for the dinuclear copper-containing enzyme tyrosinase, involving an early O-O bond-cleavage step. However, whether phenolate binding occurs before or after the cleavage of the O-O bond has not been possible to answer.

Comparison of the performance of exact-exchange-based density functional methods.

How to describe nondynamic electron correlation is still a major challenge to density functional theory (DFT). Recent models designed particularly for this problem, such as Becke'05 (B05) and Perdew-Staroverov-Tao-Scuseria (PSTS) functionals employ the exact-exchange density, the efficient calculation of which is technically quite challenging. We have recently implemented self-consistently the B05 functional based on an efficient resolution-identity (RI) technique.

Mechanistic insight into the N=N bond-cleavage of azo-compounds that was induced by an Al-Al-bonded compound [L(2-)Al(II)-Al(II)L(2-)].

An α-diimine-stabilized Al-Al-bonded compound [L(2-)Al(II)-Al(II)L(2-)] (L = [{(2,6-iPr(2)C(6)H(3))NC(Me)}(2)]; 1) consists of dianionic α-diimine ligands and sub-valent Al(2+) ions and thus could potentially behave as a multielectron reductant. The reactions of compound 1 with azo-compounds afforded phenylimido-bridged products [L(-)Al(III)(μ(2)-NPh)(μ(2)-NAr)Al(III)L(-)] (2-4). During the reaction, the dianionic ligands and Al(2+) ions were oxidized into monoanions and Al(3+), respectively, whilst the [NAr](2-) imides were produced by the four-electron reductive cleavage of the N=N double bond.

Theoretical studies of chromophore maturation in the wild-type green fluorescent protein: ONIOM(DFT:MM) investigation of the mechanism of cyclization.

The availability of a gene encoding green fluorescence immediately stimulates interest in the puzzle of autocatalytic formation of the green fluorescent protein (GFP) chromophore. Numerous experimental and theoretical studies have indicated that cyclization is the first and most important step in the maturation process of the GFP. In our previous paper based on cluster models [J.

UV-spectroscopy, electronic structure and ozonolytic reactivity of sesquiterpenes: a theoretical study.

Sesquiterpenes, one of the most important classes of biogenic volatile organic compounds, are potentially significant precursors to secondary organic aerosols (SOAs) in nature. The electronic structure of sesquiterpenes and their reactivity in the ozonolysis reaction were investigated by density functional theory. Results from the CIS calculations combined with an analysis of transition intensities show that the first peaks in the ultraviolet (UV) spectra for saturated and unsaturated isomers are σ-σ and π-π transitions, respectively.

[A quantitative real time polymerase chain reaction for detection of HBV covalently closed circular DNA in livers of the HBV infected patients].

Objective: To establish and optimize a sensitive and specific quantitative real-time polymerase chain reaction (PCR) method for detection of hepatitis B virus covalently closed circular DNA (HBV cccDNA) in liver tissue.

Methods: Specific primers and probes were designed to detect HBV DNA (tDNA) and cccDNA. A series of plasmids (3.

Quantum Chemical Modeling of Enzymatic Reactions: The Case of Decarboxylation.

We present a systematic study of the decarboxylation step of the enzyme aspartate decarboxylase with the purpose of assessing the quantum chemical cluster approach for modeling this important class of decarboxylase enzymes. Active site models ranging in size from 27 to 220 atoms are designed, and the barrier and reaction energy of this step are evaluated. To model the enzyme surrounding, homogeneous polarizable medium techniques are used with several dielectric constants.

Tungsten-dependent formaldehyde ferredoxin oxidoreductase: reaction mechanism from quantum chemical calculations.

Formaldehyde ferredoxin oxidoreductase from Pyrococcus furiosus is a tungsten-dependent enzyme that catalyzes the oxidation of formaldehyde to formic acid. In the present study, quantum chemical calculations are used to elucidate the reaction mechanism of this enzyme. Several possible mechanistic scenarios are investigated with a large model of the active site designed on the basis of the X-ray crystal structure of the native enzyme.

Theoretical investigation of the first-shell mechanism of acetylene hydration catalyzed by a biomimetic tungsten complex.

The reaction mechanism of the hydration of acetylene to acetaldehyde catalyzed by [W(IV)O(mnt)(2)](2-) (where mnt(2-) is 1,2-dicyanoethylenedithiolate) is studied using density functional theory. Both the uncatalyzed and the catalyzed reaction are considered to find out the origin of the catalysis. Three different models are investigated, in which an aquo, a hydroxo, or an oxo coordinates to the tungsten center.