Objective:To investigate the effect ofPhyllanthusurinaria L extract on hyperuricemia mice.Methods:We were randomly divided into 6 groups by weight,control and model group,(15、30、45 mg/kg)ofPhyllanthusurinaria L extr...Objective:To investigate the effect ofPhyllanthusurinaria L extract on hyperuricemia mice.Methods:We were randomly divided into 6 groups by weight,control and model group,(15、30、45 mg/kg)ofPhyllanthusurinaria L extract group and allopurinol group.There were given oteracil potassium 300 mg/kg intragastrically to induce hyperuricemiamodel without control group,Phyllanthusurinaria L extract were given by intragastric administration,there were given saline solution instead as control and model group.Uric acid,blood urea ni-trogen and creatinine was detected in serum in n hyperuricemia mice for intragastric administration eight days.the contents and activity of xanthine oxidasein liver tissue were measured in hyperuricemia mice.The pathological changes of renal tissues were observed with HE staining in groups of mice.Western blot was surveied the expression of URAT1 protein in mice kidney tissues.Results:Groups ofPhyllanthusurinaria L extract could markedly reduce the uric acid,blood urea ni-trogen and creatinine level in serum on hyperuricemia mice,at the same time it reduce the contents and activity of liver in hyperuricemia mice,high dose group of Phyllanthusurinaria L extract did particularly well,close to allopurinol group,it could improve the pathologicalchanges in kidney tissueon hyperuricemia mice better than allopurinolgroup.the expressions of URAT1 protein of the model group was increased observbly than control group(P<0.05),but high dose group ofPhyllanthusurinaria L extract group wasdecreased more than model group,same level as control group(P<0.05).Conclusion:Phyllanthusurinaria L extractcould effectively were reduced the level of Uric acid in hyperuricemia mice,there were possibly reducing XOD activity,meanwhile,there were restrained the protein expression of URAT1 and decreased morphological changes in hyperuricemia mice.展开更多
Ovalbumin-stabilized gold nanoclusters (OVA@AuNCs) were prepared with ascorbic acid as a reducing agent. This strategy could realize the synthesis of water-soluble OVA@AuNCs within 20 min. The asprepared fluorescent...Ovalbumin-stabilized gold nanoclusters (OVA@AuNCs) were prepared with ascorbic acid as a reducing agent. This strategy could realize the synthesis of water-soluble OVA@AuNCs within 20 min. The asprepared fluorescent probe showed a red fluorescence emission at 630 nm. Moreover, the properties of the OVA@AuNCs were characterized by transmission electron microscope, dynamic light scattering, ultraviolet-visible spectroscopy, fluorescent spectroscopy. Based on the surface electron density decrease-induced fluorescence quenching mechanism, the OVA@AuNCs provided high sensitivity and selectivity for sensing copper ions. A good linear relationship was obtained between the fluorescence intensity of OVA@AuNCs and the concentration of copper ions in the range of 5.0-100.0pumol/L (R2z0.999) with a detection limit of 640 nmol/L. Furthermore, the rat serum copper contents were determined by using the OVA@AuNCs based assay, indicating great potential of fluorescent probes for application in biological and clinical analysis.展开更多
Nickel alloys containing optimum amounts of chromium (Cr), molybdenum (Mo) and tungsten (W) are widely used in the chemical processing industries due to their tolerance to both oxidizing and reducing conditions....Nickel alloys containing optimum amounts of chromium (Cr), molybdenum (Mo) and tungsten (W) are widely used in the chemical processing industries due to their tolerance to both oxidizing and reducing conditions. Unlike stainless steel (SS), Ni-Cr-Mo (W) alloys exhibit remarkably high uniform corrosion resistance in major concentrated acids, like hydrochloric acid (HC1) and sulfuric acid (H2SO4). A higher uniform corrosion resistance of Ni-Cr-Mo (W) alloys, compared to other alloys, in concentrated acids can be attributed to the formation of protective oxide film of Mo and W in reducing acids, and Cr oxide film in oxidizing solutions. The localized corrosion resistance of Ni-Cr-Mo (W) alloys, containing high amount Cr as well as Mo (or Mo + W), is also significantly higher than that of other commercially available alloys. The present study investigates the role of alloying elements, in nickel alloys, to uniform corrosion resistance in concentrated acids (HC1, HC1 + oxidizing impurities and H2SO4) and localized corrosion performance in chloride-rich environments using ASTM G-48 test methodology. The corrosion tests were conducted on various alloys, and the results were analyzed using weight loss technique and electrochemical techniques, in conjunction with surface char- acterization tools.展开更多
Acute interruption of arterial blood flow to the extremities is often associated with significant morbidity and mortality. Broad spectrum mitogenic and non mitogenic activities of FGFs inspired us to study its protect...Acute interruption of arterial blood flow to the extremities is often associated with significant morbidity and mortality. Broad spectrum mitogenic and non mitogenic activities of FGFs inspired us to study its protecting effects on tissue injuries in ischemia reperfusion condition. We found that systemic administration of aFGF after reperfusion onset prevented severe skeletal muscle injuries. In rats treated with aKGF, the tissue edema was reduced significantly, the tissue viability was increased, and the muscle fibers contained more succinate dehydrogenase (SDH) and adenosine triphosphatasc (ATPase). The pathological results supported the concept of improved prevention with aFGF treatment. The possible tissue protection by aFGF may come from its ability to regulate the concentration of evtra- and intracellular calcium ion. Besides, it may moderate other Ca2+ dependent enzyme conversion processes. Also, it may take part in the vascular tone regulation under ischemia and reperfusion conditions. These results suggest further study of tissue ischemia prevention with FGF and its possible mechanisms in the future.展开更多
Sequence alignment is a common method for finding protein structurally conserved/similar regions. However, sequence alignment is often not accurate if sequence identities between to-be-aligned se- quences are less tha...Sequence alignment is a common method for finding protein structurally conserved/similar regions. However, sequence alignment is often not accurate if sequence identities between to-be-aligned se- quences are less than 30%. This is because that for these sequences, different residues may play similar structural roles and they are incorrectly aligned during the sequence alignment using substitu- tion matrix consisting of 20 types of residues. Based on the similarity of physicochemical features, residues can be clustered into a few groups. Using such simplified alphabets, the complexity of protein sequences is reduced and at the same time the key information encoded in the sequences remains. As a result, the accuracy of sequence alignment might be improved if the residues are properly clustered. Here, by using a database of aligned protein structures (DAPS), a new clustering method based on the substitution scores is proposed for the grouping of residues, and substitution matrices of residues at different levels of simplification are constructed. The validity of the reduced alphabets is confirmed by relative entropy analysis. The reduced alphabets are applied to recognition of protein structurally conserved/similar regions by sequence alignment. The results indicate that the accuracy or efficiency of sequence alignment can be improved with the optimal reduced alphabet with N around 9.展开更多
基金2016 Hainan medical university students’innovation and entrepreneurship training program(No.HYCX2016042)2017 Hainan university students’innovation and entrepreneurship training program(No.2017085)
文摘Objective:To investigate the effect ofPhyllanthusurinaria L extract on hyperuricemia mice.Methods:We were randomly divided into 6 groups by weight,control and model group,(15、30、45 mg/kg)ofPhyllanthusurinaria L extract group and allopurinol group.There were given oteracil potassium 300 mg/kg intragastrically to induce hyperuricemiamodel without control group,Phyllanthusurinaria L extract were given by intragastric administration,there were given saline solution instead as control and model group.Uric acid,blood urea ni-trogen and creatinine was detected in serum in n hyperuricemia mice for intragastric administration eight days.the contents and activity of xanthine oxidasein liver tissue were measured in hyperuricemia mice.The pathological changes of renal tissues were observed with HE staining in groups of mice.Western blot was surveied the expression of URAT1 protein in mice kidney tissues.Results:Groups ofPhyllanthusurinaria L extract could markedly reduce the uric acid,blood urea ni-trogen and creatinine level in serum on hyperuricemia mice,at the same time it reduce the contents and activity of liver in hyperuricemia mice,high dose group of Phyllanthusurinaria L extract did particularly well,close to allopurinol group,it could improve the pathologicalchanges in kidney tissueon hyperuricemia mice better than allopurinolgroup.the expressions of URAT1 protein of the model group was increased observbly than control group(P<0.05),but high dose group ofPhyllanthusurinaria L extract group wasdecreased more than model group,same level as control group(P<0.05).Conclusion:Phyllanthusurinaria L extractcould effectively were reduced the level of Uric acid in hyperuricemia mice,there were possibly reducing XOD activity,meanwhile,there were restrained the protein expression of URAT1 and decreased morphological changes in hyperuricemia mice.
基金the financial support from the National Natural Science Foundation of China(Nos. 21575144, 21475137,21375132,21635008,21621062)Chinese Academy of Sciences(No. QYZDJ-SSW-SLH034)
文摘Ovalbumin-stabilized gold nanoclusters (OVA@AuNCs) were prepared with ascorbic acid as a reducing agent. This strategy could realize the synthesis of water-soluble OVA@AuNCs within 20 min. The asprepared fluorescent probe showed a red fluorescence emission at 630 nm. Moreover, the properties of the OVA@AuNCs were characterized by transmission electron microscope, dynamic light scattering, ultraviolet-visible spectroscopy, fluorescent spectroscopy. Based on the surface electron density decrease-induced fluorescence quenching mechanism, the OVA@AuNCs provided high sensitivity and selectivity for sensing copper ions. A good linear relationship was obtained between the fluorescence intensity of OVA@AuNCs and the concentration of copper ions in the range of 5.0-100.0pumol/L (R2z0.999) with a detection limit of 640 nmol/L. Furthermore, the rat serum copper contents were determined by using the OVA@AuNCs based assay, indicating great potential of fluorescent probes for application in biological and clinical analysis.
文摘Nickel alloys containing optimum amounts of chromium (Cr), molybdenum (Mo) and tungsten (W) are widely used in the chemical processing industries due to their tolerance to both oxidizing and reducing conditions. Unlike stainless steel (SS), Ni-Cr-Mo (W) alloys exhibit remarkably high uniform corrosion resistance in major concentrated acids, like hydrochloric acid (HC1) and sulfuric acid (H2SO4). A higher uniform corrosion resistance of Ni-Cr-Mo (W) alloys, compared to other alloys, in concentrated acids can be attributed to the formation of protective oxide film of Mo and W in reducing acids, and Cr oxide film in oxidizing solutions. The localized corrosion resistance of Ni-Cr-Mo (W) alloys, containing high amount Cr as well as Mo (or Mo + W), is also significantly higher than that of other commercially available alloys. The present study investigates the role of alloying elements, in nickel alloys, to uniform corrosion resistance in concentrated acids (HC1, HC1 + oxidizing impurities and H2SO4) and localized corrosion performance in chloride-rich environments using ASTM G-48 test methodology. The corrosion tests were conducted on various alloys, and the results were analyzed using weight loss technique and electrochemical techniques, in conjunction with surface char- acterization tools.
文摘Acute interruption of arterial blood flow to the extremities is often associated with significant morbidity and mortality. Broad spectrum mitogenic and non mitogenic activities of FGFs inspired us to study its protecting effects on tissue injuries in ischemia reperfusion condition. We found that systemic administration of aFGF after reperfusion onset prevented severe skeletal muscle injuries. In rats treated with aKGF, the tissue edema was reduced significantly, the tissue viability was increased, and the muscle fibers contained more succinate dehydrogenase (SDH) and adenosine triphosphatasc (ATPase). The pathological results supported the concept of improved prevention with aFGF treatment. The possible tissue protection by aFGF may come from its ability to regulate the concentration of evtra- and intracellular calcium ion. Besides, it may moderate other Ca2+ dependent enzyme conversion processes. Also, it may take part in the vascular tone regulation under ischemia and reperfusion conditions. These results suggest further study of tissue ischemia prevention with FGF and its possible mechanisms in the future.
基金the National Natural Science Foundation of China (Grant Nos. 90403120, 10474041 and 10021001)the Nonlinear Project (973) of the NSM
文摘Sequence alignment is a common method for finding protein structurally conserved/similar regions. However, sequence alignment is often not accurate if sequence identities between to-be-aligned se- quences are less than 30%. This is because that for these sequences, different residues may play similar structural roles and they are incorrectly aligned during the sequence alignment using substitu- tion matrix consisting of 20 types of residues. Based on the similarity of physicochemical features, residues can be clustered into a few groups. Using such simplified alphabets, the complexity of protein sequences is reduced and at the same time the key information encoded in the sequences remains. As a result, the accuracy of sequence alignment might be improved if the residues are properly clustered. Here, by using a database of aligned protein structures (DAPS), a new clustering method based on the substitution scores is proposed for the grouping of residues, and substitution matrices of residues at different levels of simplification are constructed. The validity of the reduced alphabets is confirmed by relative entropy analysis. The reduced alphabets are applied to recognition of protein structurally conserved/similar regions by sequence alignment. The results indicate that the accuracy or efficiency of sequence alignment can be improved with the optimal reduced alphabet with N around 9.