Current status of research on composite bipolar plates for proton exchange membrane fuel cells (PEMFCs): nanofillers and structure optimization.

The proton exchange membrane fuel cell (PEMFC) is an efficient and clean energy source with promising applications. However, drawbacks such as high cost and low durability limit its application. Bipolar plates are an important component of PEMFCs, which not only account for a large proportion of the price and quality, but also affect the performance and durability of PEMFCs. Unlike traditional graphite and metal bipolar plates, composite bipolar plates have the advantages of easy processing, low cost, and corrosion resistance, but their lower performance limits their practical applications. This paper firstly summarizes the current research progress of various nanofillers used to improve the performance of composite bipolar plates, and discusses the improvement of the performance of composite bipolar plates by different forms and types of nanofillers. The morphological characteristics of different types of nanofillers and their effects on the improvement of conductive pathways are also analyzed. Subsequently, the means of structural optimization of composite bipolar plates are summarized, and specific optimization methods for phase interface, graphite/resin dispersion morphology, and conductive network structure are discussed in detail. Finally, challenges are discussed. Overall, this review can provide a reference for future research on composite bipolar plates.

Development of an aptamer-ampicillin conjugate for treating biofilms.

Biofilm formation involves the development of extracellular matrix and initially depends on adherence and tropism by flagellar movement. With the widespread development of antibiotic resistance and tolerance of biofilms, there is a growing need for novel anti-infective strategies. No currently approved medications specifically target biofilms. Aptamers are single-stranded nucleic acid molecules that may bind to their targets with high affinity and affect the target functions. We developed a bifunctional conjugate by linking an aptamer targeting bacterial flagella with ampicillin. We investigated its influence on biofilm prevention and dissolution by ultraviolet-visible spectrophotometry, inverted microscopy, and atomic force microscopy. This conjugate had distinctive antibacterial activity. Notably, the conjugate was more active than either component, and thus had a synergistic effect against biofilms.

Effects of rifampicin on hepatotoxicity and genes related to bile acid metabolism in mice / 中国药理学通报

Aim Toexamineliverdamagebyrifampi-cin and hepatic gene expression related to bile acid me-tabolisminmice.Methods Adultmalemicewere given rifampicin(180 mg·kg-1 ,po)daily for 30 days and(90 mg·kg-1 ,po)daily for 90 days,blood bio-chemistry,histopathology,and gene expression were examined.Results Rifampicinincreasedanimalliver index and serum enzyme activities. Histopathology showed steatosis and spotted feathery-like degenera-tion.Rifampicin increased the expression of CYP7A1 after 30 and 90 days of administration,along with in-creased FXR and SHP.Rifampicin reduced the expres-sion of BSEP after 30 days of high dose administration. Conclusion Repeatedadministrationofrifampicin may cause liver injury and intrahepatic cholestasis in mice,and these effects are associated with the altera-tion of gene expression related to bile acid metabolism.

Experimental study of osteogenic differentiation of precartilaginous stem cells induced by calcitonin gene-re-lated peptide / 中华物理医学与康复杂志

Objective To investigate the effect of calcitonin gene-related peptide ( CGRP ) in inducing os-teogenic differentiation of rat precartilaginous stem cells in vitro and the underlying mechanisms. Methods Rat pre-cartilaginous stem cells ( PSCs) were cultured in complete osteogenesis medium containing DMEM/F-12 medium and different concentrations (0, 10-8,10-9,10-10mol/L) of CGRP, the morphology changes of PSCs were observed. The proliferation of PSCs was examined at different time points by CCK-8. All the PSCs were then randomly assigned to an experimental group and a control group. The PSCs in the experimental group were cultured in complete osteogenesis medium with 10-10 mol/L CGRP , while the control group cultured merely in complete osteogenesis medium was re-ceived no special intervention. Both groups were stained by Alizarin Red and the expression of alkaline phosphatase (ALP) was detected. The osteogenic genes (RUNX2,OPN and BGP) were measured by use of RT-PCR. The activa-tion of Wnt/β-catenin signaling pathway was tested by using Western blotting to evaluate the effect of CGRP . Results Compared to the control group ( the concentration of CGRP was 0 mol/L) , the concentration of ALP was significantly higher in the experimental group, calcium deposition was significantly more obvious, and the expression of the osteogenic genes such as RUNX2,OPN and BGP as well as theβ-catenin protein expression were up-regulated significantly. However, CGRP had no effect on cell proliferation. Conclusion CGRP activated Wnt/β-catenin sig-nal pathway and induced osteogenic differentiation of precartilaginous stem cells.

Regulating osteogenic and adipogenic differentiation of bone marrow mesenchymal stem cells by extracellular adenosine triphosphate / 中国组织工程研究

BACKGROUND:Impaired balance between osteogenesis and adipogenesis of bone marrow mesenchymal stem cels is a crucial pathological mechanism of osteoporosis. Mechanical loads applied to bone tissue can increase bone formation and improve bone strength, and meanwhile lead to the release of extracelular nucleotides, such as adenosine triphosphate. OBJECTIVE: To determine the effects of adenosine triphosphate on the osteogenic and adipogenic differentiation of bone marrow mesenchymal stem cels and to investigate the underlying mechanisms. METHODS:The effect of adenosine triphosphate (10, 50, 250 μmol/L) on differentiation of bone marrow mesenchymal stem cels were measured by osteogenic and adipogenic related genes expression, alizarin red staining and oil red O staining. The activation of ERK1/2 signaling pathway by adenosine triphosphate was tested using western blot assay. RESULTS AND CONCLUSION: Incubation of bone marrow mesenchymal stem cels with adenosine triphosphate resulted in the dose-dependent increase of osteogenic genes expression and calcium deposition, and inhibition of adipogenic genes expression and lipid droplet formation, but had no effects on cel proliferation. Adenosine triphosphate activated ERK1/2 signaling pathway, and U0126 as an ERK1/2 inhibitor restrained the effect of adenosine triphosphate on the differentiation of bone marrow mesenchymal stem cels.

Cardiomyocyte apoptosis in rats with myocardial ischemia/reperfusion injury after Exendin-4 pretreatment / 中国组织工程研究

BACKGROUND:Exendin can regulate blood glucose, blood lipid and blood pressure, exert anti-inflammation and anti-oxidative stress effects, improve myocardial infarction and heart failure, and protect heart vessels. However, the effect on the apoptosis of cardiac muscle cels after ischemia/reperfusion injury remains unclear. OBJECTIVE:To observe the effects of Exendin-4 pretreatment on the cardiomyocyte apoptosis and the expression of Bcl-2 and Bax in rats with myocardial ischemia/reperfusion injury. METHODS:The myocardial ischemia/reperfusion injury model was established in rats and then received Exendin-4 pretreatment. Ischemia/reperfusion group and sham operation group were set. RESULTS AND CONCLUSION:Immunohistochemical staining, TUNEL and reverse transcriptase-polymerase chain reaction results showed that Bcl-2 protein and mRNA expression levels in the Exendin-4 group were significantly increased (P < 0.05), while Bax protein and mRNA expression levels were significantly decreased compared with ischemia/reperfusion group (P < 0.05). In addition, apoptosis index was more significantly decreased in the Exendin-4 group than in the ischemia/reperfusion group (P < 0.05). Exendin-4 can protect rat heart muscle against ischemia/reperfusion injury and effectively inhibit the apoptosis of cardiomyocytes, and the underlying mechanism is mediated by up-regulating Bcl-2 expression and down-regulating Bax expression.

Effects of ginsenoside Rg1 on expression of insulin-like growth factor-1 in brain of rats with brain contusion / 中西医结合学报

OBJECTIVE: To study the effects of ginsenoside Rg1 on the expression of insulin-like growth factor-1 (IGF-1) in the brain of rats after the experimental brain contusion. METHODS: A total of twenty-six Wistar rats were randomly divided into normal control group (n=2), untreated group (n=8) and ginsenoside Rg1 group (n=16). Brain injuries were induced in rats by a mechanical striking device. The brain tissues were extracted at different times after brain injury (6th hour, 12th hour, 2nd day, 6th day), then the expression of IGF-1 in brain tissue was examined by immunohistochemical method. RESULTS: In comparison with the normal control group, the expression of IGF-1 in the brain tissues was increased in the untreated group after the brain contusion (P<0.05). The expression of IGF-1 in brain tissues in ginsenoside Rg1 group was significantly increased as compared with the untreated group (P<0.05). CONCLUSION: Ginsenoside Rg1 enhances the recovery of the contused brain through increasing the expression of IGF-1.

Cloning, Expression and Immunization of The Hypoxanthine-guanine Phosphoribosyltransferase for Schistosoma japonicum Chinese Strain / 生物化学与生物物理进展

A 1 270 bp full-length cDNA fragment was obtained from the Schistosoma japonicum (Chinese strain) adult cDNA library after the '3' and 5' ends of the incomplete expression sequence tag (EST) of hypoxanthine-guanine phosphoribosyltransferase of Schistosoma japonicum (SjHGPRT) were amplified by the anchored PCR with 2 pairs of primer that were designed according to the published incomplete SjHGPRT EST and the sequence of multiclone sites of library λgt1 1 vector. Sequence analysis indicated that this fragment, with an identity of 82% to hypoxanthine-guanine phosphoribosyltransferase ofSchistosoma mansoni (SmHGPRT), contained a complete open reading frame(ORF). The deduced amino acid sequence showed 83% identity to that of SmHGPRT. This fragment was cloned into the prokaryotic expression vector pQE30, and subsequently sequenced and expressed in Escherichia coli. SDS-PAGE revealed that M of the recombinant protein was about 28 ku. Western-blot analysis showed that the recombinant protein was recognized by the polyclonal antisera from rabbits immunized with Schistosoma japonicum adult worm antigen. Mice vaccinated with recombinant protein revealed significant worm burden, liver eggs per gram (LEPG), fecal eggs per gram (FEPG) and intrauterine eggs of the female worms reduction percentage, compared with the controls. Taken together, the SjHGPRT full-length cDNA can be cloned and expressed in E. coli as a recombinant protein that elicited immunity against the challenge infection with Schistosoma japonicum, indicating its potential as a partia1 protection vaccine candidate.

Cloning,Expression and Immunization of The Hypoxanthine-guanine Phosphoribosyltransferase for Schistosoma japonicum Chinese Strain / 生物化学与生物物理进展

A 1 270 bp full-length cDNA fragment was obtained from the Schistosoma japonicum (Chinese strain) adult cDNA library after the 3′ and 5′ ends of the incomplete expression sequence tag (EST) of hypoxanthine-guanine phosphoribosyltransferase of Schistosoma japonicum (SjHGPRT) were amplified by the anchored PCR with 2 pairs of primer that were designed according to the published incomplete SjHGPRT EST and the sequence of multiclone sites of library ?gt11 vector. Sequence analysis indicated that this fragment, with an identity of 82% to hypoxanthine-guanine phosphoribosyltransferase of Schistosoma mansoni (SmHGPRT), contained a complete open reading frame(ORF). The deduced amino acid sequence showed 83% identity to that of SmHGPRT. This fragment was cloned into the prokaryotic expression vector pQE30, and subsequently sequenced and expressed in Escherichia coli. SDS-PAGE revealed that M of the recombinant protein was about 28 ku. Western-blot analysis showed that the recombinant protein was recognized by the polyclonal antisera from rabbits immunized with Schistosoma japonicum adult worm antigen. Mice vaccinated with recombinant protein revealed significant worm burden, liver eggs per gram (LEPG), fecal eggs per gram (FEPG) and intrauterine eggs of the female worms reduction percentage, compared with the controls. Taken together, the SjHGPRT full-length cDNA can be cloned and expressed in E.coli as a recombinant protein that elicited immunity against the challenge infection with Schistosoma japonicum, indicating its potential as a partial protection vaccine candidate.

Effects of Large Loading and Strengthening Exercises on Ratios Between Endogenous Steroid Hormones in Urine / 中国医师杂志

Objective To study the ratios between several pairs of endogenous androgens in morning urine samples from male and female athletes, so as to define their reference ranges.Also to study the effects of large loading and strengthening exercises on these ratios,which may give a halp to eliminating the misjudgement caused by stimulant misuses.Methods The steroid hormones were detected by GC-MS method through the American made HP5890 and HP5971 GC-MS,with methyl testosterone as an internal standard.The hormone concentrations were calculated by means of integral analysis to each specific ionic peak.Results The ratios An-Etio,5?/5? and T/ET in male athletes were all significantly higher than those in females(P

Changes of Serum Glycosylphosphatidylinositol Specific Phospholipase D Activity in Patients of Several Liver Diseases / 中国医师杂志

Objective To determine the changes of serum glycosylphosphatidylinositol specific phospholipase D(GPI-PLD) activity in patients of several liver disease.Method Glycosylphosphatidylinositol (GPI) anchored placental alkaline phosphatase(PLAP) prepared by ourselves was used as a substrate.After partitioning by triton-X-114,the serum GPI-PLD activity was determined quantitatively and the data was treated by microware of SPSS 10.0.Results On the basis of the percentage of GPI-anchored PLAP conversion,the sera GPI-PLD activities of total 172 patients,included 26 severe acute viral hepatitis as group A,29 liver cirrhosis as group B,32 chronic viral hepatitis as group C,55 mild acute viral hepatitis as group D,30 primary hepatocellular carcinoma as group E,were measured.As compared with 182 healthy presons as control group,the sera GPI-PLD activities of group A and B were significantly reduced;By contraries,the activities of group D and E were significantly raised.The sera GPI-PLD activities of group C compared with healthy control group were not significantly altered.However,when paired Q-test,the changes of serum GPI-PLD activity between all paired groups among this five groups were remarkable.Conclusions The determination of sera GPI-PLD activities in patients can act as a biochemistry index for diagnosis of acute viral hepatitis,liver cirrhosis and primary hepatocellular carcinoma,as well as an auxiliary index for judgment of the curative effect and prognosis of liver diseases.

Restitution and fixation of old fractures of orbita and orbital floor with vicinal facial cranium fracture by using titanium microplate / 中华医学美学美容杂志

Objective To investigate the clinical curative effect of titanium microplate to repair and fix obsolete cracky orbital fracture.Methods According to the diagnosis of CT scanning and three-dimensional imaging, 20 cases of obsolete orbital fractures were repaired and fixed by using titanium microplate along fracture lines. The microplates were placed according to the part nad shape of fractures. For the part of comminuted fractures, the two ends of fractures were fixed like a bridge. Results After the repair and fixation of titanium microplate, facial deformity became recuperative completely, eye-ball-movement and mastication function were recovered. During 6~12 months follow-up period, no reject reaction or cracking or dropping of microplate occured.Conclusions The titanium microplate can make orbital fractures rigid and internal fixed, and the procedure is simple and easy mastered. Therefore, it is one of the most effective materials in the repair and fixation of orbital and facial fractures.