This article presents several common problems.of medical injection pump through one case of ESD troubleshooting. Expounds the causes of the problem and provides solutions.
Equipment and Supplies ; Injections ; instrumentation ; Static Electricity

This paper describes electrostatic harms to oxygen pressure cabins and protection measures which should be taken.
Fires ; prevention & control ; Humans ; Humidity ; Hyperbaric Oxygenation ; Oxygen Inhalation Therapy ; instrumentation ; Static Electricity ; adverse effects

Semen-derived enhancer of viral infection(SEVI) is a peptide fragment (PAP248-286) from prostatic acid phosphatase(PAP), which can enhance human immunodeficiency virus infection. The mechanisms of SEVI include: (1) SEVI with several cationic amino acid residues reduced electrostatic repulsion between HIV virus and the target cells; (2) The disorder state of SEVI in the human body fluids was helpful to the interaction between virus and the target cell membranes; (3) SEVI could capture HIV particles directly and speed the velocity of virus on the surface of the target cells and improve adsorption and fusion. Currently, the substances of inhibiting SEVI activity include: EGCG from green tea, small molecule compound of aminoquinoline Surfen, ThT analogs BTA-EG6. Those compounds might block the combination of HIV and SEVI or prevent the formation of amyloid fibers, and then reduce the enhancement of SEVI. The studies on the biological characteristics and mechanisms of SEVI have a big benefit for the prevention and treatment of HIV infection.
HIV Infections ; etiology ; transmission ; Humans ; Male ; Semen ; physiology ; Sexually Transmitted Diseases, Viral ; etiology ; Static Electricity

To elucidate the adsorption mechanism of CS-A to the surface of titanium, 5 ml solutions of the CS-A were reacted with 2 g of native and 2 g of calcium-treated titanium powder for 48 h at 37 degrees C. Residual CS-A was detected by the carbazole elaborate method. The results showed that no CS-A attached to native titanium. Comparatively, titanium treated with calcium produced a significant adsorption of CS-A. At concentration of 60 micrograms/ml, the adsorption of CA-A to calcium-treated titanium powder attained the maximum, 83 micrograms/g. Only EDTA can liberate the bound CS-A from titanium surface. These findings suggest that calcium ion is necessary for the adsorption of CS-A to titanium.
Adsorption ; Calcium ; Chondroitin Sulfates ; pharmacology ; Static Electricity ; Surface Properties ; Titanium ; chemistry

A modified Snake algorithm for medical image segmentation based on improved Greedy method and electrostatic field model is presented in this paper. Based on Greedy method, this algorithm features a new adjacent point selection strategy and the corresponding criteria, which can be used for searching the potential snake points. A new external image force based on electrostatic field model and the simplified force field computation based on preprocessing image are also introduced. Comparative experiments indicate the validity of the method.
Algorithms ; Brain ; physiology ; Electromagnetic Fields ; Humans ; Image Processing, Computer-Assisted ; methods ; Magnetic Resonance Imaging ; methods ; Models, Theoretical ; Static Electricity

Cell Adhesion ; Cell Proliferation ; Cells, Cultured ; Chitosan ; chemistry ; Coated Materials, Biocompatible ; Collagen ; chemistry ; Humans ; Materials Testing ; Polyethyleneimine ; chemistry ; Static Electricity ; Surface Properties ; Titanium ; chemistry

To develop standard in vitro chondrosarcoma models, we synthesized three hydrogels (i. e., PDMAAm, PNaAMPS and PMETAC) and investigated the influence of Young's modulus, swelling ratio and electric charges on the behavior of chondrosarcoma cells seeded on the hydrogels, including morphology, adhesion and aggregation. Results showed that the morphology of chondrosarcoma cells at 6h was dependent on the charges of hydrogels; cells present spindle-shaped and round-shaped morphology on negative charged and neutral hydrogel, respectively, while no cells spreaded on positive charged hydrogel. Chondrosarcoma cells formed aggregates on neutral PDMAAm after further culture. The hydrogels can be synthesized easily and has the characteristics of ease at use with defined components, which holds great potential for developing standard chondrosarcoma models in vitro.
Bone Neoplasms ; pathology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Chondrosarcoma ; pathology ; Humans ; Hydrogels ; chemistry ; pharmacology ; Methacrylates ; pharmacology ; Nylons ; pharmacology ; Static Electricity

The human pregnane X receptor (hPXR) plays a critical role in the metabolism, transport and clearance of xenobiotics in the liver and intestine. The hPXR can be activated by a structurally diverse of drugs to initiate clinically relevant drug-drug interactions. In this article, in silico investigation was performed on a structurally diverse set of drugs to identify critical structural features greatly related to their agonist activity towards hPXR. Heuristic method (HM)-Best Subset Modeling (BSM) and HM-Polynomial Neural Networks (PNN) were utilized to develop the linear and non-linear quantitative structure-activity relationship models. The applicability domain (AD) of the models was assessed by Williams plot. Statistically reliable models with good predictive power and explain were achieved (for HM-BSM, r (2)=0.881, q LOO (2) =0.797, q EXT (2) =0.674; for HM-PNN, r (2)=0.882, q LOO (2) =0.856, q EXT (2) =0.655). The developed models indicated that molecular aromatic and electric property, molecular weight and complexity may govern agonist activity of a structurally diverse set of drugs to hPXR.
Computer Simulation ; Humans ; Models, Statistical ; Molecular Weight ; Neural Networks (Computer) ; Quantitative Structure-Activity Relationship ; Receptors, Steroid ; agonists ; chemistry ; Small Molecule Libraries ; chemistry ; Static Electricity

Antiviral Agents ; chemistry ; metabolism ; Crystallography, X-Ray ; Ligands ; Protein Binding ; Protein Structure, Tertiary ; RNA Helicases ; chemistry ; classification ; metabolism ; Static Electricity ; Viral Proteins ; chemistry ; classification ; metabolism ; Zika Virus ; enzymology

We review major computational chemistry techniques applied in industrial enzyme studies, especially approaches intended for guiding enzyme engineering. These include molecular mechanics force field and molecular dynamics simulation, quantum mechanical and combined quantum mechanical/molecular mechanical approaches, electrostatic continuum models, molecular docking, etc. These approaches are essentially introduced from the following two angles for viewing: one is about the methods themselves, including the basic concepts, the primary computational results, and potential advantages and limitations; the other is about obtaining valuable information from the respective calculations to guide the design of mutants and mutant libraries.
Enzymes ; chemistry ; genetics ; metabolism ; Molecular Docking Simulation ; Molecular Dynamics Simulation ; Mutant Proteins ; chemistry ; genetics ; metabolism ; Protein Engineering ; Quantum Theory ; Static Electricity