The impact of frequency and power on the ultrasonic purification of aluminum alloy.

In this study, the variations in hydrogen content and oxide content in alloys under 0 W, 500 W, 1000 W, 1500 W, 2000 W, 2500 W, 3000 W, and at 20 kHz, 30 kHz, 40 kHz were investigated. Hydrogen content was assessed using porosity and computed tomography, while oxygen content in the alloy was measured using element analyzer and elemental scanning. Compared to other conditions, the melt had the lowest hydrogen and oxide contents at a frequency of 20 kHz and an ultrasonic power of 2500 W, with values of 0.

Influence mechanism of polycrystalline diamond compact bit temperature rise based on thermo-fluid-solid coupling.

In order to improve the drilling performance of polycrystalline diamond compact bit and prolong its service life during drilling in coal rock under the action of wind cycle, the theoretical calculation model of polycrystalline diamond compact bit cutting teeth temperature was derived based on the theory of tribology and heat transfer. The theoretical temperature field of polycrystalline diamond compact bit-cutting teeth was analyzed. Using the joint simulation of EDEM-FLUENT, the temperature variation law of polycrystalline diamond compact bit cutting teeth under the thermo-fluid-solid coupling was analyzed to verify the validity of the theoretical calculation model of polycrystalline diamond compact bit cutting teeth temperature.

Pretreatment serum albumin-to-alkaline phosphatase ratio is an independent prognosticator of survival in patients with metastatic gastric cancer.

Background: Previous studies have suggested that a low albumin-to-alkaline phosphatase ratio (AAPR) is associated with a lower survival rate in patients with various malignancies. However, the relationship between pretreatment AAPR and the prognosis of patients with gastric cancer (GC) remains unclear.

Aim: To investigate the prognostic value of AAPR in distant metastatic GC.

Stick-slip vibration characteristics of drilling tool during drilling in coal seam with gangue.

Aiming at the problem of stick-slip vibration caused by sudden drilling resistance torque during drilling in coal seam with gangue, the drilling tool dynamic model with two degree of freedom was established based on the interaction between the bit cutting teeth and the coal seam with gangue. So, the motion differential equation of torsional vibration of drilling tool was derived, and the torsional vibration response of drilling tool was analyzed. Taking the drilling tool with drilling depth of 300 m as an example, the response laws of angular displacement, angular velocity, resistance torque, driving torque, relative motion phase trajectory and torsional vibration of the drill bit were discussed.

Tribological Behavior of Phenolic Resin-Based Friction Composites Filled with Graphite.

In this paper, the influence of graphite (Gr) on the dry sliding tribological properties of phenolic resin (PF) composites was studied under different sliding speeds of 3.1-47.1 m/s.

Comparison of Multiple Displacement Amplification (MDA) and Multiple Annealing and Looping-Based Amplification Cycles (MALBAC) in Limited DNA Sequencing Based on Tube and Droplet.

Whole genome amplification (WGA) is crucial for whole genome sequencing to investigate complex genomic alteration at the single-cell or even single-molecule level. Multiple displacement amplification (MDA) and multiple annealing and looping based amplification cycles (MALBAC) are two most widely applied WGA methods, which have different advantages and disadvantages, dependent on research objectives. Herein, we compared the MDA and MALBAC to provide more information on their performance in droplets and tubes.

Pressure drop characteristics of reverse circulation pneumatic cuttings removal during coal seam drilling.

To solve the problems that the borehole depth is shallow and the drilling efficiency is low during the gas drainage drilling in soft coal seam with current cuttings removal method, a new technology of reverse circulation pneumatic cuttings removal is proposed. The working principle of reverse circulation pneumatic cuttings removal is analyzed, and the kinetic equation of cuttings in the inner hole of the drill pipe is established. Through experiments, the pressure drop in the drill pipe is measured to reveal the effects of air velocity, cuttings mass flow rate, and cuttings particle size on the pressure drop in inner hole of the drill pipe.

Continuous Microfluidic Purification of DNA Using Magnetophoresis.

Automatic microfluidic purification of nucleic acid is predictable to reduce the input of original samples and improve the throughput of library preparation for sequencing. Here, we propose a novel microfluidic system using an external NdFeB magnet to isolate DNA from the polymerase chain reaction (PCR) mixture. The DNA was purified and isolated when the DNA-carrying beads transported to the interface of multi-laminar flow under the influence of magnetic field.

Development of Body Mass Index Growth Standard Chart for Chinese Preschool Children.

Background: We aimed to establish a reference standard of Body Mass Index (BMI) for the growth of preschool children in China.

Methods: We monitored and obtained the height and weight of 50702 children aged 3-6 yr in 31 provinces in mainland China in 2014. The reference standard and percentile curve of BMI preschool children aged 3-6 yr old were formulated by using Lambda-Median-Sigma (LMS) method in China.

Computation of Propagating and Non-Propagating Lamb-Like Wave in a Functionally Graded Piezoelectric Spherical Curved Plate by an Orthogonal Function Technique.

Non-propagating waves have great potential for crack evaluation, but it is difficult to obtain the complex solutions of the transcendental dispersion equation corresponding to the non-propagating wave. This paper presents an analytical approach based on the orthogonal function technique to investigate non-propagating Lamb-like waves in a functionally graded piezoelectric spherical curved plate. The presented approach can transform the set of partial differential equations for the acoustic waves into an eigenvalue problem that can give the generally complex wave numbers and the field profiles.

Cyclin-dependent kinase 5 controls vasculogenic mimicry formation in non-small cell lung cancer via the FAK-AKT signaling pathway.

Vasculogenic mimicry (VM), an endothelial-independent tumor vascularization phenomenon representing functional tumor plasticity, might be the culprit behind the poor clinical outcome in classic antiangiogenesis treatment. However, the mechanism underlying VM needs to be elucidated. Cyclin-dependent kinase 5 (CDK5) has been recognized as a key factor in regulating migration and neuronal plasticity.

Impacts of the charged residues mutation S48E/N62H on the thermostability and unfolding behavior of cold shock protein: insights from molecular dynamics simulation with Gō model.

The cold shock protein from the hyperthermophile Thermotoga maritima (Tm-Csp) exhibits significantly higher thermostability than its homologue from the thermophile Bacillus caldolyticus (Bc-Csp). Experimental studies have shown that the electrostatic interactions unique to Tm-Csp are responsible for improving its thermostability. In the present work, the favorable charged residues in Tm-Csp were grafted into Bc-Csp by a double point mutation of S48E/N62H, and the impacts of the mutation on the thermostability and unfolding/folding behavior of Bc-Csp were then investigated by using a modified Gō model, in which the electrostatic interactions between charged residues were considered in the model.

The Intrinsic Dynamics and Unfolding Process of an Antibody Fab Fragment Revealed by Elastic Network Model.

Antibodies have been increasingly used as pharmaceuticals in clinical treatment. Thermal stability and unfolding process are important properties that must be considered in antibody design. In this paper, the structure-encoded dynamical properties and the unfolding process of the Fab fragment of the phosphocholine-binding antibody McPC603 are investigated by use of the normal mode analysis of Gaussian network model (GNM).

[Correction of electrocardiogram signal baseline wander based on statistically weighted moving average filter].

Baseline wander (BW) is a common noise contaminating electrocardiogram (ECG). In order to effectively correct baseline of ECG signal and to preserve more latent components of ECG signal, this paper proposes a simple and novel filter based on statistically weighted moving average. Firstly, after the arrange between the maximum and the minimum of these sampling values in a moving window was divided into many sections with equal width, several segments [a(k), b(k)] including most samples were determined.

[Arithmetic for subtracting power line interference based on estimating sinusoidal parameters].

Electrocardiogram (ECG) signals are often contaminated by residual power-line interference. In order to filter the noise and not to distort signal too much, certain types of digital notch filters need a narrow frequency band, but such a band leads to ineffective filtering in the case of frequency deviation of the interference. In this paper, we propose a novel arithmetic.

Optimization of peptide density on microarray surface for quantitative phosphoproteomics.

Procedures to determine the density of peptides immobilized on a glass surface for the quantitative detection of phosphorylated peptides for phosphoproteomic applications of peptide microarrays are described. Two kinds of representative fluorescent probe molecules, anti-phosphotyrosine antibody (AB) and phos-tag (PT), were examined to compare their ability for the quantitative detection of phosphorylated peptides. PT is a metal complex with a binding specificity to phosphorylated amino acids, and is much smaller in size than AB.

A peptide microarray for detecting protein kinase activity in cell lysates.

Protein kinases (PKs) are widely recognized as valuable targets for disease diagnosis and drug discovery. For this reason, we have developed a sensitive peptide microarray for detecting intracellular PK activity. Peptides are immobilized on a glutaraldehyde-premodified high-amino terminal glass slide, by spotting 2 nL volumes of substrate peptide solutions with an automated microarray spotter.

Protein kinase substrate profiling with a high-density peptide microarray.

We describe a powerful peptide microarray for profiling protein kinase substrates that combines the merits of chemoselective immobilization of peptides to achieve high density spots with the advantages of fluorescence-based analysis of phosphorylation for nonhazardous detection. For detection of on-chip phosphorylation, we used a fluorescence-labeled antiphosphotyrosine antibody to detect phosphotyrosine and a biotinylated Phostag, which was subsequently bound with a fluorescence-labeled streptavidin for phosphoserine/threonine. More than 290 kinds of Tyr peptides and over 1,100 kinds of Ser/Thr peptides were chemoselectively immobilized onto a glass surface in a high-density format to profile a panel of protein kinases, including c-Src, c-Abl, EGFR, JNK1, ERK2, p38α, and PKA.

Transplantation of sertoli-islet cell aggregates formed by microgravity: prolonged survival in diabetic rats.

Transplantation of pancreatic islets is a potentially attractive treatment for type I diabetes. We generated the transplantable, tissue-like aggregates composed of Sertoli cells and islets in rotating wall vessel bioreactors, SICA (Sertoli-islet cell aggregates), to improve their biological function in vitro and in vivo. The isolated islet equivalent and Sertoli cells were purified from Wistar rats and cocultured for 5 days in bioreactor to generate SICA.

Monitoring protein kinase activity in cell lysates using a high-density peptide microarray.

Monitoring and targeting protein kinases is widely accepted as a promising approach for disease diagnosis and drug discovery. For this purpose, the authors have developed an original type of peptide array as a high-throughput screening assay for quantitatively evaluating kinase activity. A volume of 2 nL of peptide solution was spotted onto a formyl group-modified glass slide by using an arrayer, which was designed for use with protein chip technology.

Evaluation of protein kinase activities of cell lysates using peptide microarrays based on surface plasmon resonance imaging.

We developed a peptide microarray based on surface plasmon resonance (SPR) imaging for monitoring protein kinase activities in cell lysates. The substrate peptides of kinases were tethered to the microarray surface modified with a self-assembled monolayer of an alkanethiol with triethylene glycol terminus to create a low nonspecific binding surface. The phosphorylation of the substrate peptides immobilized on the surface was detected with the following phosphate specific binders by amplifying SPR signals: anti-phosphotyrosine antibody for tyrosine kinases and Phos-tag biotin (a phosphate-specific ligand with biotin tag) for serine/threonine kinases.

Surface plasmon resonance imaging measurements of caspase reactions on peptide microarrays.

Enzymatic activity monitoring of caspases, which are a class of cysteine protease, was performed by using peptide arrays based on surface plasmon resonance (SPR) imaging. The strategy of the detection is straightforward, using streptavidin to amplify the SPR signals of the surface-immobilized substrate peptides labeled with biotin at the C termini. Thus, the cleavage of the substrate peptides by caspases was detected as a signal decrease.

A quantitative peptide array for evaluation of protein kinase activity.

Peptide array, which is known as an emerging technology, has been developed for identification of protein kinase activity. For this purpose, the ability of quantitative analysis is very important because the absolute change in protein kinase activity is critical for the determination of cellular function. Here we report an original type of peptide array for quantitative evaluation of protein kinase activity by fluorescence imaging.