A novel esterase EstC10 from Bacillus sp. CX01 isolated from the deep sea of the Western Pacific Ocean and the functionalities of EstC 10 was characterized. At present, the reports about the kinetic resolution ofracem...A novel esterase EstC10 from Bacillus sp. CX01 isolated from the deep sea of the Western Pacific Ocean and the functionalities of EstC 10 was characterized. At present, the reports about the kinetic resolution ofracemic methyl 2-chloropropionate were quite rare. So we developed deep-sea microbial esterase EstC10 as a novel biocatalyst in the kinetic resolution of racemic methyl 2-chloropropionate and generate （R）-methyl 2-chloropropionate with high enantiomeric excess （〉99%） after the optimization of process parameters such as pH, temperature, organic co-solvents, surfactants, substrate concentration and reaction time. Notably, the optimal substrate concentration （80 mmol/L） of esterase EstC10 was higher than the kinetic resolution of another esterase, Estl2-7 （50 mmoFL）. The novel microbial esterase EstC10 identified from the deep sea was a promising green biocatalyst in the generation of （R）-methyl 2-chloropropionate as well of many other valuable chiral chemicals in industry.展开更多
BACKGROUND： MicroRNA （miRNA） expression in stem cells provides important clues for the molecular mechanisms of stem cell proliferation and differentiation. Bone marrow stromal cells and spinal cord-derived neural s...BACKGROUND： MicroRNA （miRNA） expression in stem cells provides important clues for the molecular mechanisms of stem cell proliferation and differentiation. Bone marrow stromal cells and spinal cord-derived neural stem cells exhibit potential for neural regeneration. However, miRNA expression in these cells has been rarely reported. OBJECTIVE： To explore differential expression of two nervous system-specific miRNAs, miR-124 and miR-128, in bone marrow stromal cells and spinal cord-derived neural stem cells. DESIGN, TIME AND SETTING： An In vitro, cell biology experiment was performed at the Department of Biotechnology, Shanxi Medical University from June 2008 to June 2009. MATERIALS： TaqMan miRNA assays were purchased from Applied Biosystems. METHODS： Rat bone marrow stromal cells were isolated and cultured using the whole-bone marrow method, and rat spinal cord-derived neural stem cells were obtained through neurosphere formation. TaqMan miRNA assays were used to measure miR-124 and miR-128 expression in bone marrow stromal cells and spinal cord-derived neural stem cells. MAIN OUTCOME MEASURES： Morphology of bone marrow stromal cells and spinal cord-derived neural stem cells were observed by inverted microscopy. Expression of the neural stem cell-specific marker, nestin, the bone marrow stromal cell surface marker, CD71, and expression of miR-124 and miR-128, were detected by real-time polymerase chain reaction. RESULTS： Cultured bone marrow stromal cells displayed a short fusiform shape. Flow cytometry revealed a large number of CD71-positive cells （〉 95%）. Cultured spinal cord-derived neural stem cells formed nestin-positive neurospheres, and quantitative detection of miRNA demonstrated that less miR-124 and miR-128 was expressed in bone marrow stromal cells compared to spinal cord-derived neural stem cells （P 〈 0.05）. CONCLUSION： Bone marrow stromal cells and spinal cord-derived neural stem cells exhibited differential expression of miR-124 and miR-128, which suggested different characteristics in miRNA expression.展开更多
Obesity is known to be a major risk factor of type 2 diabetes （T2D） and responsible for most lipid abnormalities associated with the disease but limited data on such association are available for diabetic patients o...Obesity is known to be a major risk factor of type 2 diabetes （T2D） and responsible for most lipid abnormalities associated with the disease but limited data on such association are available for diabetic patients of Igbo ethnicity in the South East region of Nigeria. A case-control study involving 72 T2D patients and 75 non-diabetic （ND） patients （control） ofIgbo ethnicity was conducted. Demographic and anthropometric data were obtained followed by blood collection for the determination of fasting blood sugar （FBS）, total cholesterol （TC）, triglyceride （TG）, high density lipoprotein （HDL） and low density lipoprotein （LDL）. Obesity based on waist circumference （WC） was significantly higher （p 〈 0.001） in T2D patients compared to their non-diabetic counterparts. Similarly, TC, TG and LDL levels were significantly （p 〈 0.001） higher in T2D patients while HDL was significantly lower （p 〈 0.001） in T2D patients compared to the control. The proportion of dyslipidaemia characterized by high TC, high TG, high LDL and low HDL was significantly higher （p 〈 0.001） in T2D patients. BMI correlated positively （p 〈 0.05） with WC, TC, and LDL while FBS correlated positively （p 〈 0.05） with TG but negatively with HDL. In conclusion, dyslipidaemia characterised by hypercholesterolaemia, hypertriglyceridaemia, elevated LDL and reduced HDL, as well as obesity were associated with T2D and correlated with FBS in this population.展开更多
This study demonstrated a solvothermal method of growth of three different morphologies of zinc oxide nanoparticles （ZnO NPs）： i） flower-like nanorod and nanoflakes, ii） assembled hierarchical structure, and iii...This study demonstrated a solvothermal method of growth of three different morphologies of zinc oxide nanoparticles （ZnO NPs）： i） flower-like nanorod and nanoflakes, ii） assembled hierarchical structure, and iii） nano granule. Oleic acid （C18H3402）, gluconic acid （C6H1207） and tween 80 （C64H124026） were used as surfactant/capping/reducing agent for the formation of different morphologies of nanoparticles. The as-synthesized ZnO NPs were characterized by different physicochemical techniques such as UV-vis （UV-vis） spectroscopy, X-ray diffraction （XRD）, fourier transform infrared spectroscopy （FFIR）, field emission scanning electron microscopy （FE-SEM）, energy dispersive X-ray （EDX） analysis and dynamic light scattering （DLS） studies. Further, the antioxidant and antimicrobial activity of these nanostructures was evaluated. The antioxidant activity of these nanostructures was assessed via 2,2-diphenyl,1-1 picrylhydrazyl （DPPH）, 2,2＇-azino-bis （3-ethylbenzothiazoline-6-sulphonic acid） （ABTS） and H202 free radical scavenging activity. The in vitro antimicrobial activity of the obtained nanostructures was demonstrated against both gram negative （Escherichia coil） and gram positive （Staphylococcus aureus） bacterial genera. This study revealed antioxidant and antimicrobial properties of different structures ofZnO NPs suggesting their biomedical and industrial applications.展开更多
Biorecycling microbes, which have critical functionalities in natural cycles, are essential to sustain eco-system of the earth. Any alterations in these cycles caused by the mutations of microbes could be a potential ...Biorecycling microbes, which have critical functionalities in natural cycles, are essential to sustain eco-system of the earth. Any alterations in these cycles caused by the mutations of microbes could be a potential threat to life on earth. Antibiotics leached from pharmaceutical waste, animal food and agribusiness prod- ucts are accumulating in the environment. Metal nanoparticles are also accumulating in environment because of their extensive use as biocidal agent in domestic products. Interaction of antibiotics and metal nanoparticles with eco-ffiendly microorganisms has a potential to alter the ecosystem of the earth. In this article, we have studied the antibacterial activities of silver and copper nanoparticles and their for- mulations with antibiotics, tetracycline, and kanamycin against biorecycling microbes, Bacillus subtilis and Pseudomonas fluorescens. Strong synergistic effect of metal nanoparticles on the antimicrobial ac- tivities of commercial antibiotics has been observed. Antimicrobial activity of tetracycline improves by 286%-346% and 0%-28% when being tested in the presence of 250 ppm of silver and copper nanoparticles, respectively. For kanamycin, the improvement is 154%-289% for silver and 3%-20% for copper nanoparticles. Irrespective of the antibiotics and tested organisms, synergy is more prominent for silver nanoparticles even at their minimum active concentration （100 ppm）. This study demonstrates that the combination of metal nanoparticles with antibiotics could be more fatal to ecosystem than either the metal nanoparticles or the antibiotics alone.展开更多
基金Supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA11030404)the Guangzhou Science and Technology Plan Projects(No.201510010012)the National Natural Science Foundation of China(No.21302199)
文摘A novel esterase EstC10 from Bacillus sp. CX01 isolated from the deep sea of the Western Pacific Ocean and the functionalities of EstC 10 was characterized. At present, the reports about the kinetic resolution ofracemic methyl 2-chloropropionate were quite rare. So we developed deep-sea microbial esterase EstC10 as a novel biocatalyst in the kinetic resolution of racemic methyl 2-chloropropionate and generate （R）-methyl 2-chloropropionate with high enantiomeric excess （〉99%） after the optimization of process parameters such as pH, temperature, organic co-solvents, surfactants, substrate concentration and reaction time. Notably, the optimal substrate concentration （80 mmol/L） of esterase EstC10 was higher than the kinetic resolution of another esterase, Estl2-7 （50 mmoFL）. The novel microbial esterase EstC10 identified from the deep sea was a promising green biocatalyst in the generation of （R）-methyl 2-chloropropionate as well of many other valuable chiral chemicals in industry.
基金the National Natural Science Foundation of China, No. 30672114
文摘BACKGROUND： MicroRNA （miRNA） expression in stem cells provides important clues for the molecular mechanisms of stem cell proliferation and differentiation. Bone marrow stromal cells and spinal cord-derived neural stem cells exhibit potential for neural regeneration. However, miRNA expression in these cells has been rarely reported. OBJECTIVE： To explore differential expression of two nervous system-specific miRNAs, miR-124 and miR-128, in bone marrow stromal cells and spinal cord-derived neural stem cells. DESIGN, TIME AND SETTING： An In vitro, cell biology experiment was performed at the Department of Biotechnology, Shanxi Medical University from June 2008 to June 2009. MATERIALS： TaqMan miRNA assays were purchased from Applied Biosystems. METHODS： Rat bone marrow stromal cells were isolated and cultured using the whole-bone marrow method, and rat spinal cord-derived neural stem cells were obtained through neurosphere formation. TaqMan miRNA assays were used to measure miR-124 and miR-128 expression in bone marrow stromal cells and spinal cord-derived neural stem cells. MAIN OUTCOME MEASURES： Morphology of bone marrow stromal cells and spinal cord-derived neural stem cells were observed by inverted microscopy. Expression of the neural stem cell-specific marker, nestin, the bone marrow stromal cell surface marker, CD71, and expression of miR-124 and miR-128, were detected by real-time polymerase chain reaction. RESULTS： Cultured bone marrow stromal cells displayed a short fusiform shape. Flow cytometry revealed a large number of CD71-positive cells （〉 95%）. Cultured spinal cord-derived neural stem cells formed nestin-positive neurospheres, and quantitative detection of miRNA demonstrated that less miR-124 and miR-128 was expressed in bone marrow stromal cells compared to spinal cord-derived neural stem cells （P 〈 0.05）. CONCLUSION： Bone marrow stromal cells and spinal cord-derived neural stem cells exhibited differential expression of miR-124 and miR-128, which suggested different characteristics in miRNA expression.
文摘Obesity is known to be a major risk factor of type 2 diabetes （T2D） and responsible for most lipid abnormalities associated with the disease but limited data on such association are available for diabetic patients of Igbo ethnicity in the South East region of Nigeria. A case-control study involving 72 T2D patients and 75 non-diabetic （ND） patients （control） ofIgbo ethnicity was conducted. Demographic and anthropometric data were obtained followed by blood collection for the determination of fasting blood sugar （FBS）, total cholesterol （TC）, triglyceride （TG）, high density lipoprotein （HDL） and low density lipoprotein （LDL）. Obesity based on waist circumference （WC） was significantly higher （p 〈 0.001） in T2D patients compared to their non-diabetic counterparts. Similarly, TC, TG and LDL levels were significantly （p 〈 0.001） higher in T2D patients while HDL was significantly lower （p 〈 0.001） in T2D patients compared to the control. The proportion of dyslipidaemia characterized by high TC, high TG, high LDL and low HDL was significantly higher （p 〈 0.001） in T2D patients. BMI correlated positively （p 〈 0.05） with WC, TC, and LDL while FBS correlated positively （p 〈 0.05） with TG but negatively with HDL. In conclusion, dyslipidaemia characterised by hypercholesterolaemia, hypertriglyceridaemia, elevated LDL and reduced HDL, as well as obesity were associated with T2D and correlated with FBS in this population.
文摘This study demonstrated a solvothermal method of growth of three different morphologies of zinc oxide nanoparticles （ZnO NPs）： i） flower-like nanorod and nanoflakes, ii） assembled hierarchical structure, and iii） nano granule. Oleic acid （C18H3402）, gluconic acid （C6H1207） and tween 80 （C64H124026） were used as surfactant/capping/reducing agent for the formation of different morphologies of nanoparticles. The as-synthesized ZnO NPs were characterized by different physicochemical techniques such as UV-vis （UV-vis） spectroscopy, X-ray diffraction （XRD）, fourier transform infrared spectroscopy （FFIR）, field emission scanning electron microscopy （FE-SEM）, energy dispersive X-ray （EDX） analysis and dynamic light scattering （DLS） studies. Further, the antioxidant and antimicrobial activity of these nanostructures was evaluated. The antioxidant activity of these nanostructures was assessed via 2,2-diphenyl,1-1 picrylhydrazyl （DPPH）, 2,2＇-azino-bis （3-ethylbenzothiazoline-6-sulphonic acid） （ABTS） and H202 free radical scavenging activity. The in vitro antimicrobial activity of the obtained nanostructures was demonstrated against both gram negative （Escherichia coil） and gram positive （Staphylococcus aureus） bacterial genera. This study revealed antioxidant and antimicrobial properties of different structures ofZnO NPs suggesting their biomedical and industrial applications.
基金financially supported by the University Grants Commission,New Delhi(scheme No.F.No.42-850/2013(SR))
文摘Biorecycling microbes, which have critical functionalities in natural cycles, are essential to sustain eco-system of the earth. Any alterations in these cycles caused by the mutations of microbes could be a potential threat to life on earth. Antibiotics leached from pharmaceutical waste, animal food and agribusiness prod- ucts are accumulating in the environment. Metal nanoparticles are also accumulating in environment because of their extensive use as biocidal agent in domestic products. Interaction of antibiotics and metal nanoparticles with eco-ffiendly microorganisms has a potential to alter the ecosystem of the earth. In this article, we have studied the antibacterial activities of silver and copper nanoparticles and their for- mulations with antibiotics, tetracycline, and kanamycin against biorecycling microbes, Bacillus subtilis and Pseudomonas fluorescens. Strong synergistic effect of metal nanoparticles on the antimicrobial ac- tivities of commercial antibiotics has been observed. Antimicrobial activity of tetracycline improves by 286%-346% and 0%-28% when being tested in the presence of 250 ppm of silver and copper nanoparticles, respectively. For kanamycin, the improvement is 154%-289% for silver and 3%-20% for copper nanoparticles. Irrespective of the antibiotics and tested organisms, synergy is more prominent for silver nanoparticles even at their minimum active concentration （100 ppm）. This study demonstrates that the combination of metal nanoparticles with antibiotics could be more fatal to ecosystem than either the metal nanoparticles or the antibiotics alone.
