Effects of friction stir processing and nano-hydroxyapatite on the microstructure,hardness,degradation rate and in-vitro bioactivity of WE43 alloy for biomedical applications

Nowadays,magnesium alloys are emerging in biomedical implants for their similar properties to natural bones.However,the rapid degradation of magnesium alloys in biological media hinders successful implantation.Refinement of microstructure,as well as reinforcement particles can significantly improve the degradation rate.In this work,multi-pass friction stir processing(FSP)was proposed to synthesize WE43/nano-hydroxyapatite(n HA)surface composite,the microstructure,reinforced particle distribution,micro-hardness,corrosion behavior and in-vitro bioactivity were studied.The subsequent FSP passes of WE43 alloy and WE43/n HA composite refined the grain size which was reduced by 94.29%and 95.92%(2.63 and 1.88μm,respectively)compared to base metal after three passes.This resulted in increasing the microhardness by 120%(90.86 HV0.1)and 135%(105.59 HV0.1)for the WE43 and WE43-n HA,respectively.It is found that increasing FSP passes improved the uniform distribution of n HA particles within the composite matrix which led to improved corrosion resistance and less degradation rate.The corrosion rate of the FSPed WE43/n HA composite after three passes was reduced by 38.2%(4.13 mm/year)and the degradation rate was reduced by 69.7%(2.87 mm/y).This is attributed to secondary phase(Mg24Y5and Mg41Nd5)particle fragmentation and redistribution,as well as a homogeneous distribution of n HA.Additionally,the growing Ca-P and Mg(OH)2layer formed on the surface represented a protective layer that reduced the degradation rate.The wettability test revealed a relatively hydrophilic surface with water contact angle of 49.1±2.2°compared to 71.2±2.1°for base metal.Also,biomineralization test showed that apatite layer grew after immersion 7d in simulated body fluid with atomic ratio of Ca/P 1.60 approaching the stoichiometric ratio(1.67)indicating superior bioactivity of FSPed WE43/n HA composite after three passes.These results raise that the grain refinement by FSP and introduction of n HA particles significantly improved the degradation rate and in-vitro bioactivity of WE43 alloy for biomedical applications.

Research Progress on Structure and Bioactivity of Longan Polysaccharide

Longan originates from southern China and has high nutritional and health value.Recent phytochemistry and pharmacology studies have shown that polysaccharides are a main bioactive component of longan.Longan polysaccharides possess antioxidant,anti-aging,anti-tumor,immunomodulatory,and other bioactivities.Hot-water extraction,ethanol precipitation,and ultrasonic extraction are generally used to extract water-soluble longan polysaccharides.However,the relationship between the structure and bioactivity of longan polysaccharides remains unclear,requiring further investigation.The aim of this review is to evaluate the current literature focusing on the extraction,purification,structural characterization,and biological activity of longan polysaccharides.We believe that this review would provide a useful bibliography for further innovation and a basis for using longan polysaccharides in functional food.

Influence of mental stress on platelet bioactivity

It is well established that various mental stress conditions contribute, or at least influence, underlying pathophysiological mechanisms in somatic, as well as in psychiatric disorders; blood platelets are supposed to represent a possible link in this respect. The anculeated platelets are the smallest corpuscular elements circulating in the human blood. They display different serotonergic markers which seem to reflect the central nervous serotonin metabolism. They are known as main effectors in haematological processes but recent research highlights their role in the innate and adaptive immune system. Platelets are containing a multitude of pro-inflammatory and immune-modulatory bioactive compounds in their granules and are expressing immune-competent surface markers. Research gives hint that platelets activation and reactivity is increased by mental stress. This leads to enhanced cross talk with the immune system via paracrine secretion, receptor interaction and formation of platelet leucocyteaggregates. Recently it has been demonstrated that the immune system can have a remarkable impact in the development of psychiatric disorders. Thereforeplatelets represent an interesting research area in psychiatry and their role as a possible biomarker has been investigated. We review the influence of mental stress on what is termed platelet bioactivity in this article, which subsumes the mainly immune-modulatory activity of platelets in healthy volunteers, elderly persons with chronic care-giving strain, patients with cardiovascular diseases who are prone to psychosocial stress, as well as in patients with posttraumatic stress disorder. Research data suggest that stress enhances platelet activity, reactivity and immune-modulatory capacities.

Synthesis, Characterization and Bioactivity of Complexes of Rare Earth with Bis-Schiff Base from Furoylpyrazolone

Eleven new complexes of rare earths with bis-Schiff base derived from N,N'-bis[(1-phenyl-3-methyl-5-oxo-4-pyrazolinyl) alpha-furylmethylidyne] ethylenediimine ((HPM alpha FP)(2)en) were synthesized. On the basis of elemental analysis and molar conductance, a general formula of the complexes, [RE(HPM alpha FP)(2)en(NO3)(2)]NO3(RE = La, Pr, Nd, Sm, Eu, Th, Dy, Ho, Er, Yb,Y), was given. The complexes were characterized by IR, UV-visible, H-1 NMR, C-13 NMR and fluorescence. The results show that the bis-Schiff base is a quadridentate ligand and the rare earth ions exhibit coordination of eight in the complexes. The antibacterial experiments indicate that they have high antibacterial activities against S. aureus, B. subtillis, E. coli, E. carotovora, C. flaccumfaciens.

In Situ Laser Coating of Calcium Phosphate on TC4 Surface for Enhancing Bioactivity

Titanium alloy has been a successful implant material owing to its excellent ratio of strength to weight, toughness, and bio-inert oxide surface. Significant progress has been made in improving the bioactivity of titanium alloy by coating its oxide surface with calcium phosphates. In the present study, in situ coating was reported on Ti6Al4V（TC4） surface with calcium phosphate （Ca-P） bioceramics synthesized and synchronously cladded by laser beam. This coating was grown by first preplacing directly the raw powders, which contain 80% of CaHPO4 · 2H2O, 20% of CaCO3, and dram of rare earth （RE）, on the TC4 surfaces, and then exposing the surfaces to the laser beam with a power density of 12. 73-15.27 MW · m^-2 and a scanning velocity of 10.5 m/s. The resultant coating was characterized using scanning electron microscopy （SEM）, X-ray diffraction （XRD）, thermogravimetric analysis and Different-thermal Scanning （TG-DSC）, and Energy Dispersive X-ray Detection （EDX）. The results show that these laser ceramics include hydroxyapatite （HA）, tricalcium phosphate （TCP）, Ca2 P2 O7, and other Ca-P phases, and the interface between the coating and the TC4 substrate has tighter fixation, in which the chemical bonding is approved. These laser hybrid coatings are useful in enhancing the bioactivity of titanium alloy surfaces.

Isolation and characterization of anti-diabetic component(bioactivity-guided fractionation) from Ocimum sanctum L.(Lamiaceae) aerial part

Objective:To isolate and characterize antidiabetic component（bioactivity-guided fractionation） from hydro alcoholic extract of Ocimum sanctum（O.sanctum） aerial part.Methods:Ten fractions（F1 - F10） were isolated from hydro alcoholic extract of O.sanctum aerial part by column chromatography.All the fractions Fl to F10 were screened for antidiabetic activity in alloxan induced diabetic rats by estimating serum glucose level and lipid parameters.The isolated bioactive component was elucidated on the basis of extensive spectroscopic(UV,IR,MS,1H and 13C NMR) data analysis.Results:The bioactive fraction（F5） was found to be potent antidiabetic by ameliorating glucose and lipid parameters（total cholesterol,triglycerides,low and high density lipoprotein cholesterol）.The extensive spectroscopic data analysis reveals that,the isolated bioactive compound elucidated as tetracyclic triterpenoid[16-Hydroxy-4,4,10,13-tetramethyl- 17-（4-methyI-pentyl）-hexadecahydro-cyclopenta[a]phenanthren-3-one].Conclusions:Our present study concluded that,tetracyclic triterpenoid isolated from aerial part of O.sanctum has a great anti-diabetic potential.

Effects of Traditional Chinese Medicinal Plants on Antiinsulin Resistance Bioactivity of DXMS-Induced Insulin Resistant HepG2 Cells

Medicinal plants have a long history of use in China to treat diabetic symptoms.Ancient Chinese medical manuscripts and ethnobotanical surveys document plant remedies that continue to be actively used in China for the treatment of diabetic symptoms.Based on a systematic ancient Chinese medical manuscripts review in combination with ethnobotanical survey,16 medicinal plants for the traditional treatment of diabetic symptoms were identified for the evaluation of anti-insulin resistance bioactivity.The biological activity of 16 medicinal plants was tested on dexamethasone(DXMS)-induced insulin resistant HepG2 cells.The result shows that 11 of the 16 medicinal plants enhanced glucose uptake of DXMS-induced insulin resistant HepG2 cells,thereby demonstrating their ability to increase insulin sensitivity,other five medicinal plants including Astragalus membranaceus were found ineffective.The study shows that ancient Chinese medical manuscripts and ethnobotanical surveys on plants for the prevention and treatment of diabetic symptoms provide a promising knowledge base for drug discovery to mitigate the global diabetes epidemic.

Recombinant amelogenin regulates the bioactivity of mouse cementoblasts in vitro

Amelogenin（AMG） is a cell adhesion molecule that has an important role in the mineralization of enamel and regulates events during dental development and root formation. The purpose of the present study was to investigate the effects of recombinant human AMG（rhAMG） on mineralized tissue-associated genes in cementoblasts. Immortalized mouse cementoblasts（OCCM-30）were treated with different concentrations（0.1, 1, 10, 100, 1 000, 10 000, 100 000 ng · mL^-1） of recombinant human AMG（rhAMG）and analyzed for proliferation, mineralization and mRNA expression of bone sialoprotein（BSP）, osteocalcin（OCN）, collagen type I（COL I）, osteopontin（OPN）, runt-related transcription factor 2（Runx2）, cementum attachment protein（CAP）, and alkaline phosphatase（ALP） genes using quantitative RT-PCR. The dose response of rhAMG was evaluated using a real-time cell analyzer.Total RNA was isolated on day 3, and cell mineralization was assessed using von Kossa staining on day 8. COL I, OPN and lysosomalassociated membrane protein-1（LAMP-1）, which is a cell surface binding site for amelogenin, were evaluated using immunocytochemistry. F-actin bundles were imaged using confocal microscopy. rhAMG at a concentration of 100 000 ng · mL^-1 increased cell proliferation after 72 h compared to the other concentrations and the untreated control group. rhAMG（100 000 ng · mL^-1） upregulated BSP and OCN mRNA expression levels eightfold and fivefold, respectively. rhAMG at a concentration of 100 000 ng · mL^-1 remarkably enhanced LAMP-1 staining in cementoblasts. Increased numbers of mineralized nodules were observed at concentrations of 10 000 and 100 000 ng · mL^-1 rhAMG. The present data suggest that rhAMG is a potent regulator of gene expression in cementoblasts and support the potential application of rhAMG in therapies aimed at fast regeneration of damaged periodontal tissue.

Synthesis, Bioactivity and Crystal Structure Analysis of 2-(Benzo[d]isothiazol-3-yloxy)-N-(3-cyano-1-(4-fluorophenyl)-1H-pyrazol-5-yl) Acetamide

A novel benzisothiazolin-3-one derivative, 2-（benzo[d]isothiazol-3-yloxy）-N-（3- cyano-l-（4-fluorophenyl）-lH-pyrazol-5-yl） acetamide （8）, was synthesized from the initial compound benzo[d]isothiazol-3（2H）-one （BIT） 1 and 4-fluoroaniline 3. The structure of the target compound 8 was determined by elemental analyses, IR and 1H NMR. The single crystals of intermediate compound 6 and the target compound 8 were obtained and determined by X-ray diffraction analysis. The preliminary biological activity was also evaluated and the results showed tile target compound exhibited a good anti-microbial activity.

Selection of appropriate analytical tools to determine the potency and bioactivity of antibiotics and antibiotic resistance

Antibiotics are the chemotherapeutic agents that kill or inhibit the pathogenic microorganisms.Resistance of microorganism to antibiotics is a growing problem around the world due to indiscriminate and irrational use of antibiotics.In order to overcome the resistance problem and to safely use antibiotics,the correct measurement of potency and bioactivity of antibiotics is essential.Microbiological assay and high performance liquid chromatography（HPLC） method are used to quantify the potency of antibiotics.HPLC method is commonly used for the quantification of potency of antibiotics,but unable to determine the bioactivity;whereas microbiological assay estimates both potency and bioactivity of antibiotics.Additionally,bioassay is used to estimate the effective dose against antibiotic resistant microbes.Simultaneously,microbiological assay addresses the several parameters such as minimal inhibitory concentration（MIC）,minimum bactericidal concentration（MBC）,mutation prevention concentration（MPC） and critical concentration（Ccr） which are used to describe the potency in a more informative way.Microbiological assay is a simple,sensitive,precise and cost effective method which gives reproducible results similar to HPLC.However,the HPLC cannot be a complete substitute for microbiological assay and both methods have their own significance to obtain more realistic and precise results.

Conceptual Density Functional Theory Study of the Chemical Reactivity Properties and Bioactivity Scores of the Leu-Enkephalin Opioid Peptide Neurotransmitter

The SMD solvation model (Solvation Model based on the Density) and eight density functionals, CAM-B3LYP, LC-ωPBE, M11, MN12SX, N12SX, ωB97, ωB97X, and ωB97XD, were assessed in link with the Def2TZVP basis set for the calculation of the structure of the Leu-Enkephalin Opioid Peptide Neurotransmitter as well as their molecular properties. Through the Conceptual Density Functional Theory (CDFT), the entire chemical descriptors for the system were calculated. The active regions of the molecules necessary for electrophilic, nucleophilic and radical attacks were chosen through linking them with the corresponding Fukui functions. Furthermore, the prediction of the pKa value for the peptide is done with great accuracy as well as the ability of the studied molecule in acting as an efficient inhibitor of the formation of Advanced Glycation Endproducts (AGEs), which comprises of a useful knowledge for the development of drugs for preventing Alzheimer, Diabetes and Parkinson diseases. Lastly, the bioactivity scores for the studied peptides are predicted via various methodologies.

Synthesis,Crystal Structure and Bioactivity of N-Phenethyl-4-hydroxy-4-phenyl Piperidine Hydrochloride

A novel compound N-phenethyl-4-hydroxy-4-phenyl piperidine hydrochloride （C19H24ClNO·H2O） has been synthesized and structurally characterized by elemental analysis, IR, ^1H NMR spectra and single-crystal X-ray diffraction. The crystal belongs to orthorhombic, space group P212121 with a = 8.6306（8）, b = 11.0464（10）, c = 19.3221（18）A^°, V = 1842.1（3）A^°^3, Z = 4, Dc =1.211 g/cm^3,μ = 0.217 mm^-1, Mr= 335.86, F（000） = 720, S = 0.973, R = 0.0420 and wR = 0.1009 for 3627 unique reflections with 3157 observed ones （I 〉 2σ（I））. In the crystal, the dihedral angles made by piperidine ring with two benzene rings are 84.8（6） and 62.5（7）°, respectively. Intermolecular O-H…O and O-H…Cl hydrogen bonds involving water molecules form chains along the b axis, which stabilizes the crystal structure. The preliminary bioactivity tests indicated that the title compound has good effect of cellular growth inhibition to K562 cells and potential bioactivity of anti-leukemia.

A Bioactivity Versus Ethnobotanical Survey of Medicinal Plants from Nigeria, West Africa

Traditional medicinal practices play a key role in health care systems in countries with developing economies.The aim of this survey was to validate the use of traditional medicine within local Nigerian communities.In this review,we examine the ethnobotanical uses of selected plant species from the Nigerian flora and attempt to correlate the activities of the isolated bioactive principles with known uses of the plant species in African traditional medicine.Thirty-three(33)plant species were identified and about 100 out of the 120 compounds identified with these plants matched with the ethnobotanical uses of the plants.

Syntheses and Bioactivity of 4″-Sulfonate-5-triphenylsilyl Avermectin B_(1a) and Ivermectin B_(1a) Derivatives

Fourteen new derivatives of avermectin B_(1a) and ivermectin B_(1a) were synthesized from C_5-O-triphenylsilyl avermectin B_(1a) and ivermectin B_(1a)(yield from 40% to 83%). Their chemical structures were characterized by means of IR, ()~1H NMR, ()^(13)C NMR and FAB-MS spectrometries. Some of them show excellent insecticidal activity.

Preparation and bioactivity of sol-gel macroporous bioactive glass

Bioactive glass is well known for its ability of bone regeneration, and sol-gel bioactive glass has many advantages compared with melt-derived bioactive glass. 3-D scaffold prepared by the sol-gel method is a promising substrate material for bone tissue engineering and large-scale bone repair. Porous sol-gel glass in the CaO-SiO2-P205 system with macropores larger than 100 μm was prepared by the addition of stearic acid as a pore former. The diameter of the pore created by the pore former varied from 100 to 300 μm. The formation of a hydroxyapatite layer on the glass was analyzed by studying the surface of the porous glass by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and Raman spectra after they had been immersed in simulated body fluid （SBF） for some time, and the porous glass shows good bioactivity.

Chemical Reactivity Properties, Drug-Likeness Features and Bioactivity Scores of the Cholecystokinin Peptide Hormone

Five density functionals, CAM-B3LYP, LC-ωPBE, MN12SX, N12SX and ωB97XD, in connection with the Def2TZVP basis set were assessed together with the SMD solvation model for the calculation of the molecular and chemical reactivity properties of the Cholecystokinin peptide hormone (CCK-8) in the presence of water. All the chemical reactivity descriptors for the systems were calculated via Conceptual Density Functional Theory (CDFT). The potential bioavailability and druggability as well as the bioactivity scoresfor CCK-8 were predicted through different methodologies already reported in the literature which have been previously validated during the study of different peptidic systems. The conclusion was that the CCK-8 peptide will be moderately bioactive regarding all the interactions.

EXPRESSING HUMAN MATURED BRAIN-DERIVED NEUROTROPHIC FACTOR GENE IN E.Coli AND DETERMINING ITS BIOACTIVITY

Objective Expressing the human matured brain-derived neurotrophic factor (mBDNF) gene in E. Coli and determining its bioactivity. Methods The resulting gene of mBDNF was subcloned into the EcoRI-BamHI site or the expression vector plasmid pBV220. The ligation products were used to transform the competent E. Coli DH5a. The proteins or mBDNF were experessed by temperature inducing. The expression products were dealed with solubilizing inclusion bodies and refolding protein. It was introduced into the embryonic chicken DRG to test whether the expressed mBDNF is a biologically active protein. Results The recombinant plasmid pBV/mBDNF was success- fully constructed. By temperature inducing, under the control of the bacteriophage λPL promoter, the experessed mBDNF protein was a 14Kd non-fusion protein,which existed in E. Coli as inclusion bodies. The size or expressed mBDNF is identical to the prediction. Bioactivity of the products was proved that it could support the cell survival and neurite growth in the primary cultures of embryonic 8-day-old chicken DRG neurons as compared to control. Conclusion Tke mBDNF gene can be expressed bioactively in E. Coli.

Isolated Endophytic Fungi from the Plant <i>Curcuma longa</i>and Their Potential Bioactivity—A Review

Endophytes (both fungi and bacteria) represent a treasure house for bioactive compounds such as anticancer, immunomodulatory, antioxidant, antiparasitic, insecticidal etc. for use in the pharmaceutical and agrochemical industries. Endophytic population is greatly influenced by climatic conditions and location where the host plant grows. Curcuma longa L. (Turmeric) is a medicinal plant belonging to the Zingiberaceae family that is usually used as spice and preservative. Traditionally it is used to treat various conditions and symptoms such as digestive disorders, arthritis, cardiovascular conditions, cancer, bacterial infections etc. In recent times, there have been different discoveries on endophytic fungi and their biological activity from C. longa. But there is no comprehensive review on endophytic fungi of C. longa. The aim of this review is to analyze the published report based on the endophytic fungi to provide for the first time an updated information about their isolation from different tissues, their biological activities including the phytochemistry of C. longa. This will lead the way to forecast the missing link for future research work.

Diversity and Bioactivity of Cultivable Animal Fecal Actinobacteria

Microbial symbionts play important roles in food digestion and absorption, immunity, pathogens resistance, and health maintaining of their hosts by coevolution. To provide new sources for discovering new leader compounds of drugs, the diversity and bioactivities of cultivable actinobacteria from animal feces have been studied. 31 species of animal fecal samples were collected fromYunnanWildAnimalPark. The purified cultures of actinobacteria were isolated from these samples by using 5 media. The 16S rRNA gene sequences of 528 selected strains were determined, the phylogenetic analysis was carried out, and anti-microbial and anti-tumor activities were determined. 35 genera (including a new genus, Enteractinococcus) of actinobacteria from the 31 species of animal feces were identified. Some strains had high anti-tumor and antimicrobial activities. More than 50 secondary metabolites were isolated and identified, a novel bioactive macrolactam polyketide glycoside, Sannastatin, was found. Nine fecal streptomycete strains were fermented respectively, blended to the microbial manure, and used to prophylaxis and treatment of soil-borne disease of notoginseng in field. The incidence rate of the disease was lower 81% than agricultural chemicals. Fecal actinobacteria, a possibility as a new source for discovering drug leader, agricultural chemicals and other industry products, will be discussed.