AIM: To investigate the effect of nutritional support therapy on severe acute pancreatitis (SAP).METHODS: A total of 96 patients with severe acute pancreatitis were divided randomly into control and treatment groups.T...AIM: To investigate the effect of nutritional support therapy on severe acute pancreatitis (SAP).METHODS: A total of 96 patients with severe acute pancreatitis were divided randomly into control and treatment groups.The former group received total parenteral nutrition (TPN)via central venous infusion, while parenteral nutrition (PN)and enteral nutrition (EN) therapies were applied in different phases for the latter group. The nutrition status, acute phase responses, pancreas lesions, enteric mucosa penetrability and immune functions were monitored.RESULTS: Body weight and prealbumin concentration were increased in treatment group, compared to those in the control group, but albumin concentration did not change significantly.Acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ)scores decreased after 7 d of treatment, whereas the scores of the control group decreased on the 11th day. Concentrations of tumor necrosis factor-α (TNF-α), interleukine-6 (IL-6) and serum C reactive protein (CRP) dropped earlier in the treatment group (on the 4th day) than that in the control group (on the 7th day). No difference was observed in pancreatic lesions between the control and treatment groups.Concentration of endotoxin and lactulose/manicol (L:M) ratio of urine did not change in treatment group, but those in the control group were elevated markedly. Compared with the treatment group, CD4:CD8 T cells ratio and immunoglobulin G (IgG) concentration in the control group decreased significantly.CONCLUSION: Compared to TPN, the combined therapy of EN and PN could improve the nutrition status and moderate the acute phase response obviously. Moreover, the integrity of enteric mucosa and immune function were protected more effectively in treatment group than in the control one. On the other hand, EN did not simulate the excretion of pancreas and avoid exaggerating the inflammation of pancreas. Thus,appropriate application of PN and EN appears to be more effective for patients with SAP.展开更多
AIM:To study the function of N-myc downstream-regulated gene 1 (NDRG1) in colorectal carcinogenesis and its correlation with tumor lymph node metastasis,METHODS:NDRG1 was detected at its protein level by immunohistoch...AIM:To study the function of N-myc downstream-regulated gene 1 (NDRG1) in colorectal carcinogenesis and its correlation with tumor lymph node metastasis,METHODS:NDRG1 was detected at its protein level by immunohistochemistry (IHC) and image analysis (IA), and NDRG1 mRNA was detected by in situ hybridization (ISH) in formalin-fixed and paraffin-embedded sections with a total of 190 specimens including 38 normal colorectal mucosae, 31 colorectal adenomas, 45 non-metastatic colorectal carcinomas (CRCs), 38 metastatic primary CRC and subsequently regional lymph nodes respectively. At the same time, the correlations of NDRG1 with sex, age of patients and histological types of colorectal carcinomas were observed.RESULTS: NDRG1 proteins were gradually increased in colorectal carcinogenesis (P<0.05 or P<0.01). There was a significant difference in the expression of NDRG1 between non-metastatic and metastatic CRCs (P<0.05), and the correlation was positive (P<0.01, rs=0.329). However, there was no obvious difference in the expression of NDRG1 between the primary sites of CRCs and that in the metastatic sites of corresponding regional lymph nodes, nor was there an apparent difference in sex, age, and histological types.The expression of NDRG1 mRNA was generally in concordance with that of NDRG1 protein.CONCLUSION: NDRG1 gene may play an important role in colorectal carcinogenesis.In addition, NDRG1 may be a putative tumor metastasis promoter gene and is regarded as one of the molecular biological markers that can forecast early metastasis of CRCs. NDRG1 gene in the metastatic sites of regional lymph nodes may preserve its expression characteristics in the primary sites of CRCs to some extent.The expression of NDRG1 is not affected by sex, age and histological types. The role of NDRG1 in tumor metastatic process can be demonstrated by in vivo and in vitro.展开更多
Electrocatalytic hydrogenation(ECH)of organics using water as hydrogen donors has been regarded as a green organic reduction technique to replace traditional chemical reactions that use sacrificial chemicals.The devel...Electrocatalytic hydrogenation(ECH)of organics using water as hydrogen donors has been regarded as a green organic reduction technique to replace traditional chemical reactions that use sacrificial chemicals.The development of ECH process provides potential applications in the production of value-added chemicals owing to its low energy consumption,low pollution,high safety,and superior sustainability.However,its application is limited by the low conversion rate and poor selectivity toward desired products.The efficiency of ECH can be improved by rational design of electrocatalysts.This review covers several representative electrocatalytic systems(aldehydes,ketones,phenolic organics,alkynes,and organonitrogen compounds)and summarizes different ECH mechanisms,followed by thorough discussion on the modification strategies of electrocatalysts that are currently adopted to enhance the catalytic performance.Finally,in view of the current challenges for ECH,we discuss possible future directions in the field,aiming to provide guidance to the catalyst design toward highly efficient ECH reactions over different organic feedstocks.展开更多
AIM: To examine the effects of berberine, an isoquinoline alkaloid with a long history used as a tonic remedy for liver and heart, on ion channels of isolated rat hepatocytes.METHODS: Tight-seal whole-cell patch-clamp...AIM: To examine the effects of berberine, an isoquinoline alkaloid with a long history used as a tonic remedy for liver and heart, on ion channels of isolated rat hepatocytes.METHODS: Tight-seal whole-cell patch-clamp techniques were performed to investigate the effects of berberine on the delayed outward potassium currents (Ik), inward rectifier potassium currents (Ik1) and Ca^2+ release-activated Ca^+ currents (ICRAC) in enzymatically isolated rat hepatocytes.RESULTS: Berbenne 1-300 μmol/L reduced/K in a concentration-dependent manner with EC50 of 38.86=1=5.37 μmol/L and nH of 0.82±0.05 (n = 8). When the bath solution was changed to tetraethylammonium (TEA) 8 retool/L,IK was inhibited.Berberine 30 μmol/L reduced/K at all examined membranepote ntials, especially at potentials positive to +60 mV (n = 8,P<0.05 or P<0.01 vs control). Berberine had mild inhibitory effects on IK1 in rat hepatocytes. Berberine 1-300 μmol/L also inhibited ICRAC in a concentration-dependent fashion. The fitting parameters were EC50 = 47.20±10.86 μmol/L,nH= 0.71±0.09 (n = 8). The peak value of/CRAC in the I-Vrelationship was decreased by berberine 30 μmol/L at potentialnegative to -80 mV (n = 8, P<0.05 vscontrol). But the reverse potential of/CRAC occurred at voltage 0 mV in all cells.CONCLUSION: Berberine has inhibitory effects on potassium and calcium currents in isolated rat hepatocytes, which may be involved in hepatoprotection.展开更多
AIM: To study the effects of palmatine, a known inhibitoron delayed rectifier potassium current and L-type calciumcurrent (ICa,L) in guinea pig ventricular myocytes, on thepotassium and calcium currents in isolated ra...AIM: To study the effects of palmatine, a known inhibitoron delayed rectifier potassium current and L-type calciumcurrent (ICa,L) in guinea pig ventricular myocytes, on thepotassium and calcium currents in isolated rat hepatocytes.METHODS: Tight-seal wh ole-cell patch-clamp techniqueswere performed to investigate the effects of palmatine onthe delayed outward potassium currents (IK), inward rectifierpotassium current (IK1) and Ca2+ release-activated Ca2+current (ICRAC) in enzymatically isolated rat hepatocytes.RESULTS: Palmatine 0.3-100 μM reduced IK in a concentationdependent manner with EC50of 41.62±10.11 μM and nH,0.48±0.07 (n=8). The effect of the drug was poorly reversibleafter washout. When the bath solution was changed totetraethylammonium (TEA) 8 mM, IK was inhibited.Palmatine 10 μM and 100 μM shifted the I-V curves of IKdownward, and the block of IK was voltage-independent.Palmatine 0.3-100 μM also inhibited ICRAC in a concentration-dependent manner. The fitting parameters were as follows:ECs0=51.19±15.18 μM, and nH=0.46+0.07 (n=8). The peakvalue of ICRAC in the I-V relationship was decreased bypalmatine 10 μM and 100 μM. But the reverse potential ofIcRAcoCcurred at Voltage=0 mV in all cells. Palmatine 0.3-100 μM failed to have any significant effect on either inwardor outward components of IK1 at any membrane potentialexamined.CONCLUSION: The inhibitory effects on IK and ICRAC couldbe one of the mechanisms that palmatine exerts protectiveeffect on hepatocytes.展开更多
In contrast to alkaline water electrolysis,acidic water electrolysis remains an elusive goal due to the lack of earth-abundant,efficient,and acid-stable water oxidation electrocatalysts.Here,we show that materials wit...In contrast to alkaline water electrolysis,acidic water electrolysis remains an elusive goal due to the lack of earth-abundant,efficient,and acid-stable water oxidation electrocatalysts.Here,we show that materials with intrinsically poor electrocatalytic activity can be turned into active electrocatalysts that drive the acidic oxygen evolution reaction(OER)effectively.This development is achieved through ultrafast plasma sputtering,which introduces abundant oxygen vacancies that reconstruct the surface electronic structures,and thus,regulated the surface interactions of electrocatalysts and the OER intermediates.Using tungsten oxide(WO_(3))as an example,we present a broad spectrum of theoretical and experimental characterizations that show an improved energetics of OER originating from surface oxygen vacancies and resulting in a significantly boosted OER performance,compared with pristine WO_(3).Our result suggests the efficacy of using defect chemistry to modify electronic properties and hence to improve the OER performance of known materials with poor activity,providing a new direction for the discovery of acid-stable OER catalysts.展开更多
We obtain an ahnost sure central limit theorem(ASCLT)for heavily trimmed sums.We also prove a function-typed ASCLT under the same conditions that assure measurable functions to satisfy the ASCLT for the partial sums o...We obtain an ahnost sure central limit theorem(ASCLT)for heavily trimmed sums.We also prove a function-typed ASCLT under the same conditions that assure measurable functions to satisfy the ASCLT for the partial sums of i.i.d,random variables with EX_1=0,EX_1~2=1.展开更多
AIM: To study the effects of AP-Q on CCl4-induced acute liver injury, delayed outward potassium current (Iκ), inward rectifier potassium current (Iκ1) and calcium release-activated calcium current (ICRAC) in isolate...AIM: To study the effects of AP-Q on CCl4-induced acute liver injury, delayed outward potassium current (Iκ), inward rectifier potassium current (Iκ1) and calcium release-activated calcium current (ICRAC) in isolated rat hepatocytes. METHODS: A single dose of CCl4 (10 μg/mL, ip) was injected to induce acute liver injury in rats. Serum aminotransferase activities were determined. Whole cell patch-clamp techniques were used to investigate the effects of AP-Q on delayed outward potassium current (Iκ), inward rectifier potassium current (IKI) and calcium release-activated calcium current (ICRAC). RESULTS: AP-Q (3.5 and 7 μg/kg) pretreatment significantly reduced ALT and AST activities. AP-Q 0.1-100 nM produced a concentration-dependent increase of Iκ with EC50 value of 5.55±1.8 nM (n=6). AP-Q 30 nM shifted the I-V curve of Iκ leftward and upward. CCl4 4 mM decreased Iκ current 28.6±0.5% at 140 mV. After exposure to CCl4 for 5 rain, AP-Q 30 nM attenuated the decrease of Iκ induced by CCl4 close to normal amplitude. AP-Q 0.01-100 nM had no significant effect on either inward or outward components of Iκ1 at any membrane potential examined. AP-Q 0.1-100 nM had no significant influence on the peak amplitude of ICRAC, either,and did not affect the shape of its current voltage curve. CONCLUSION: AP-Q has a protective effect on CCl4-induced liver injury, probably through selectively increased Iκ in hepatocytes.展开更多
AIM: To study the effect of progesterone on contractile activity of isolated gastric strips in rats.METHODS: Wistar rats were sacrificed to remove whole stomach. Then, the stomach was opened and the mucosal layer was ...AIM: To study the effect of progesterone on contractile activity of isolated gastric strips in rats.METHODS: Wistar rats were sacrificed to remove whole stomach. Then, the stomach was opened and the mucosal layer was removed. Parellel to either the circular or the longitudial fibers, muscle strips were cut from fundus, body,antrum and pylorus. Each muscle strip was suspended in a tissue chamber containing 5 mL Krebs solution. Then the motility of gastric strips in tissue chambers was simultaneously recorded. The preparations were subjected to 1 g load tension and washed with 5 ml Krebs solution every 20 min. After 1 h equilibration, progesterone or antagonists were added in the tissue chamber separately. The antagonists were added 3 min before using progesterone (50 μmol. L-1).RESULTS: Progesterone decreased the resting tension of fundus and body longitudinal muscle (LM) (P＜0.05). It inhibited the mean contractile amplitude of body and antrum LM and circular muscle (CM), and the motility index of pyloric CM (P＜0.05). The inhibition of progesterone on the mean contractile amplitude could be partially blocked by phentolamine in LM of the stomach body (the mean contractile amplitude of body LM decreased from -7.5±5.5to -5.2±4.5 P＜0.01), and by phentolamine or indomethacin in CM of body (The inhibition of progesterone on the mean contractile amplitude of body CM decreased from -5.6±3.0to -3.6±2.7 by phentolamine and from -5.6±3.0 to -3.5±2.5by indomethacin, P＜0.01). Hexamethonium, propranolol and L-NNA (inhibitor of NO synthetase) didn′t affect the action of progesterone (P＞0.05).CONCLUSION: The study suggested that progesterone can inhibit the contractile activity of isolated gastric strips in rats and the mechanism seems to be a direct one except that the action on gastric body is mediated through prostaglandin and adrenergic α receptor partly.展开更多
AIM: Activation of glial metabotropic glutamate receptors (mGluRs) may be proved to play a critical role for neuroprotection in neurodegenerative diseases. Excess glutamate induced-excitoxicity is implicated in the in...AIM: Activation of glial metabotropic glutamate receptors (mGluRs) may be proved to play a critical role for neuroprotection in neurodegenerative diseases. Excess glutamate induced-excitoxicity is implicated in the initiation or progression of the neurodegenerative process. Glutamate accumulation in the central nervous system mediated by inhibiting展开更多
AIM:To investigate the radiation response of various human tumor cells and normal liver cells. METHODS: Cell lines of human hepatoma cells (SMMC-7721), liver cells (L02), melanoma cells (A375) and cervical tumor (HeLa...AIM:To investigate the radiation response of various human tumor cells and normal liver cells. METHODS: Cell lines of human hepatoma cells (SMMC-7721), liver cells (L02), melanoma cells (A375) and cervical tumor (HeLa) were irradiated with 60Co γ-rays. Cell survive was documented by a colony assay. Chromatid breaks were measured by counting the number of chromatid breaks and isochromatid breaks immediately after prematurely chromosome condensed by Calyculin-A. RESULTS: Linear quadratic survival curve was observed in all of four cell lines, and dose-dependent increase in radiation-induced chromatid and isochromatid breaks were observed in GB2B phase. Among these four cell lines, A375 was most sensitive to radiation, while, L02 had the lowest radiosensitivity. For normal liver cells, chromatid breaks were easy to be repaired, isochromatid breaks were difficult to be repaired. CONCLUSION: The results suggest that the y-rays induced chromatid breaks can be possibly used as a good predictor of radiosensitivity, also, unrejoined isochromatid breaks probably tightly related with cell cancerization.展开更多
To test the accuracy of real-time three-dimensional echocardiography (RT3DE) imaging system for evaluating left ventricular mass (LVM) in phantom and excised canine heart. Methods Ten left ventricular (LV) wall phanto...To test the accuracy of real-time three-dimensional echocardiography (RT3DE) imaging system for evaluating left ventricular mass (LVM) in phantom and excised canine heart. Methods Ten left ventricular (LV) wall phantoms made of two rubber-bursas, ten excised canine hearts underwent RT3DE and two-dimensional echocardiography (2DE). In RT3DE "full volume" imaging, the myocardial volume was mea-sured using 2,4,8, and 16-plane method with the analysis software of RT3DE. Mass was then calculated by multiplying the resulting myocardial volume by specific density of myocardial tissue. In 2DE the masses were measured by area-length meth-od. The true LV wall phantom mass was measured by water displacement and the canine LVM was weighed by anatomy, which served as a reference standard. We compared RT3DE or 2DE with true mass. Results In LV wall phantoms, RT3DE correlated with true masses strongly (r = 0.813-0.994) and weakly correlated between 2DE and true masses (r = 0.628). In excised canine hearts, there is an excellent correlation between RT3DE and true masses (r = 0.764-0.991), while 2DE value showed a lesser correlation (r = 0.514). There are no difference between RT-3DE and true masses (P > 0.05) but different between 2DE and true masses (P < 0.05). In different planes, there was no difference between 8-plane and 16-plane (P > 0.05) but different between 8-plane and 2, 4-plane (P < 0.05). Conclusion RT3DE can accurately quantify LVM and provide a new tool to evaluate LV function. For LVM by RT3DE, 8-plane measurement method is the best choice for accuracy and convenience.展开更多
文摘AIM: To investigate the effect of nutritional support therapy on severe acute pancreatitis (SAP).METHODS: A total of 96 patients with severe acute pancreatitis were divided randomly into control and treatment groups.The former group received total parenteral nutrition (TPN)via central venous infusion, while parenteral nutrition (PN)and enteral nutrition (EN) therapies were applied in different phases for the latter group. The nutrition status, acute phase responses, pancreas lesions, enteric mucosa penetrability and immune functions were monitored.RESULTS: Body weight and prealbumin concentration were increased in treatment group, compared to those in the control group, but albumin concentration did not change significantly.Acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ)scores decreased after 7 d of treatment, whereas the scores of the control group decreased on the 11th day. Concentrations of tumor necrosis factor-α (TNF-α), interleukine-6 (IL-6) and serum C reactive protein (CRP) dropped earlier in the treatment group (on the 4th day) than that in the control group (on the 7th day). No difference was observed in pancreatic lesions between the control and treatment groups.Concentration of endotoxin and lactulose/manicol (L:M) ratio of urine did not change in treatment group, but those in the control group were elevated markedly. Compared with the treatment group, CD4:CD8 T cells ratio and immunoglobulin G (IgG) concentration in the control group decreased significantly.CONCLUSION: Compared to TPN, the combined therapy of EN and PN could improve the nutrition status and moderate the acute phase response obviously. Moreover, the integrity of enteric mucosa and immune function were protected more effectively in treatment group than in the control one. On the other hand, EN did not simulate the excretion of pancreas and avoid exaggerating the inflammation of pancreas. Thus,appropriate application of PN and EN appears to be more effective for patients with SAP.
文摘AIM:To study the function of N-myc downstream-regulated gene 1 (NDRG1) in colorectal carcinogenesis and its correlation with tumor lymph node metastasis,METHODS:NDRG1 was detected at its protein level by immunohistochemistry (IHC) and image analysis (IA), and NDRG1 mRNA was detected by in situ hybridization (ISH) in formalin-fixed and paraffin-embedded sections with a total of 190 specimens including 38 normal colorectal mucosae, 31 colorectal adenomas, 45 non-metastatic colorectal carcinomas (CRCs), 38 metastatic primary CRC and subsequently regional lymph nodes respectively. At the same time, the correlations of NDRG1 with sex, age of patients and histological types of colorectal carcinomas were observed.RESULTS: NDRG1 proteins were gradually increased in colorectal carcinogenesis (P<0.05 or P<0.01). There was a significant difference in the expression of NDRG1 between non-metastatic and metastatic CRCs (P<0.05), and the correlation was positive (P<0.01, rs=0.329). However, there was no obvious difference in the expression of NDRG1 between the primary sites of CRCs and that in the metastatic sites of corresponding regional lymph nodes, nor was there an apparent difference in sex, age, and histological types.The expression of NDRG1 mRNA was generally in concordance with that of NDRG1 protein.CONCLUSION: NDRG1 gene may play an important role in colorectal carcinogenesis.In addition, NDRG1 may be a putative tumor metastasis promoter gene and is regarded as one of the molecular biological markers that can forecast early metastasis of CRCs. NDRG1 gene in the metastatic sites of regional lymph nodes may preserve its expression characteristics in the primary sites of CRCs to some extent.The expression of NDRG1 is not affected by sex, age and histological types. The role of NDRG1 in tumor metastatic process can be demonstrated by in vivo and in vitro.
基金supported by the Fundamental Research Funds for the Central Universities in China(No.20720210010)National Natural Science Foundation of China(No.22001081)+2 种基金the Science and Technology Projects of Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM,Grant No.:HRTP-[2022]-7)Xiamen University.Qiu Jiang acknowledges the China Postdoctoral Science Foundation funded project(2022M710601)the University of Electronic Science and Technology of China for startup funding(Y030212059003039).
文摘Electrocatalytic hydrogenation(ECH)of organics using water as hydrogen donors has been regarded as a green organic reduction technique to replace traditional chemical reactions that use sacrificial chemicals.The development of ECH process provides potential applications in the production of value-added chemicals owing to its low energy consumption,low pollution,high safety,and superior sustainability.However,its application is limited by the low conversion rate and poor selectivity toward desired products.The efficiency of ECH can be improved by rational design of electrocatalysts.This review covers several representative electrocatalytic systems(aldehydes,ketones,phenolic organics,alkynes,and organonitrogen compounds)and summarizes different ECH mechanisms,followed by thorough discussion on the modification strategies of electrocatalysts that are currently adopted to enhance the catalytic performance.Finally,in view of the current challenges for ECH,we discuss possible future directions in the field,aiming to provide guidance to the catalyst design toward highly efficient ECH reactions over different organic feedstocks.
文摘AIM: To examine the effects of berberine, an isoquinoline alkaloid with a long history used as a tonic remedy for liver and heart, on ion channels of isolated rat hepatocytes.METHODS: Tight-seal whole-cell patch-clamp techniques were performed to investigate the effects of berberine on the delayed outward potassium currents (Ik), inward rectifier potassium currents (Ik1) and Ca^2+ release-activated Ca^+ currents (ICRAC) in enzymatically isolated rat hepatocytes.RESULTS: Berbenne 1-300 μmol/L reduced/K in a concentration-dependent manner with EC50 of 38.86=1=5.37 μmol/L and nH of 0.82±0.05 (n = 8). When the bath solution was changed to tetraethylammonium (TEA) 8 retool/L,IK was inhibited.Berberine 30 μmol/L reduced/K at all examined membranepote ntials, especially at potentials positive to +60 mV (n = 8,P<0.05 or P<0.01 vs control). Berberine had mild inhibitory effects on IK1 in rat hepatocytes. Berberine 1-300 μmol/L also inhibited ICRAC in a concentration-dependent fashion. The fitting parameters were EC50 = 47.20±10.86 μmol/L,nH= 0.71±0.09 (n = 8). The peak value of/CRAC in the I-Vrelationship was decreased by berberine 30 μmol/L at potentialnegative to -80 mV (n = 8, P<0.05 vscontrol). But the reverse potential of/CRAC occurred at voltage 0 mV in all cells.CONCLUSION: Berberine has inhibitory effects on potassium and calcium currents in isolated rat hepatocytes, which may be involved in hepatoprotection.
文摘AIM: To study the effects of palmatine, a known inhibitoron delayed rectifier potassium current and L-type calciumcurrent (ICa,L) in guinea pig ventricular myocytes, on thepotassium and calcium currents in isolated rat hepatocytes.METHODS: Tight-seal wh ole-cell patch-clamp techniqueswere performed to investigate the effects of palmatine onthe delayed outward potassium currents (IK), inward rectifierpotassium current (IK1) and Ca2+ release-activated Ca2+current (ICRAC) in enzymatically isolated rat hepatocytes.RESULTS: Palmatine 0.3-100 μM reduced IK in a concentationdependent manner with EC50of 41.62±10.11 μM and nH,0.48±0.07 (n=8). The effect of the drug was poorly reversibleafter washout. When the bath solution was changed totetraethylammonium (TEA) 8 mM, IK was inhibited.Palmatine 10 μM and 100 μM shifted the I-V curves of IKdownward, and the block of IK was voltage-independent.Palmatine 0.3-100 μM also inhibited ICRAC in a concentration-dependent manner. The fitting parameters were as follows:ECs0=51.19±15.18 μM, and nH=0.46+0.07 (n=8). The peakvalue of ICRAC in the I-V relationship was decreased bypalmatine 10 μM and 100 μM. But the reverse potential ofIcRAcoCcurred at Voltage=0 mV in all cells. Palmatine 0.3-100 μM failed to have any significant effect on either inwardor outward components of IK1 at any membrane potentialexamined.CONCLUSION: The inhibitory effects on IK and ICRAC couldbe one of the mechanisms that palmatine exerts protectiveeffect on hepatocytes.
基金supported by the King Abdullah University of Science and Technology(KAUST)。
文摘In contrast to alkaline water electrolysis,acidic water electrolysis remains an elusive goal due to the lack of earth-abundant,efficient,and acid-stable water oxidation electrocatalysts.Here,we show that materials with intrinsically poor electrocatalytic activity can be turned into active electrocatalysts that drive the acidic oxygen evolution reaction(OER)effectively.This development is achieved through ultrafast plasma sputtering,which introduces abundant oxygen vacancies that reconstruct the surface electronic structures,and thus,regulated the surface interactions of electrocatalysts and the OER intermediates.Using tungsten oxide(WO_(3))as an example,we present a broad spectrum of theoretical and experimental characterizations that show an improved energetics of OER originating from surface oxygen vacancies and resulting in a significantly boosted OER performance,compared with pristine WO_(3).Our result suggests the efficacy of using defect chemistry to modify electronic properties and hence to improve the OER performance of known materials with poor activity,providing a new direction for the discovery of acid-stable OER catalysts.
基金Supported by the National Natural Science Foundation of China(No.10071003)Beijing Municipal Education Commission(KM200310028107)
文摘We obtain an ahnost sure central limit theorem(ASCLT)for heavily trimmed sums.We also prove a function-typed ASCLT under the same conditions that assure measurable functions to satisfy the ASCLT for the partial sums of i.i.d,random variables with EX_1=0,EX_1~2=1.
文摘AIM: To study the effects of AP-Q on CCl4-induced acute liver injury, delayed outward potassium current (Iκ), inward rectifier potassium current (Iκ1) and calcium release-activated calcium current (ICRAC) in isolated rat hepatocytes. METHODS: A single dose of CCl4 (10 μg/mL, ip) was injected to induce acute liver injury in rats. Serum aminotransferase activities were determined. Whole cell patch-clamp techniques were used to investigate the effects of AP-Q on delayed outward potassium current (Iκ), inward rectifier potassium current (IKI) and calcium release-activated calcium current (ICRAC). RESULTS: AP-Q (3.5 and 7 μg/kg) pretreatment significantly reduced ALT and AST activities. AP-Q 0.1-100 nM produced a concentration-dependent increase of Iκ with EC50 value of 5.55±1.8 nM (n=6). AP-Q 30 nM shifted the I-V curve of Iκ leftward and upward. CCl4 4 mM decreased Iκ current 28.6±0.5% at 140 mV. After exposure to CCl4 for 5 rain, AP-Q 30 nM attenuated the decrease of Iκ induced by CCl4 close to normal amplitude. AP-Q 0.01-100 nM had no significant effect on either inward or outward components of Iκ1 at any membrane potential examined. AP-Q 0.1-100 nM had no significant influence on the peak amplitude of ICRAC, either,and did not affect the shape of its current voltage curve. CONCLUSION: AP-Q has a protective effect on CCl4-induced liver injury, probably through selectively increased Iκ in hepatocytes.
基金Natural Science Foundation of Province of Gansu Province,No:ZR-96-085
文摘AIM: To study the effect of progesterone on contractile activity of isolated gastric strips in rats.METHODS: Wistar rats were sacrificed to remove whole stomach. Then, the stomach was opened and the mucosal layer was removed. Parellel to either the circular or the longitudial fibers, muscle strips were cut from fundus, body,antrum and pylorus. Each muscle strip was suspended in a tissue chamber containing 5 mL Krebs solution. Then the motility of gastric strips in tissue chambers was simultaneously recorded. The preparations were subjected to 1 g load tension and washed with 5 ml Krebs solution every 20 min. After 1 h equilibration, progesterone or antagonists were added in the tissue chamber separately. The antagonists were added 3 min before using progesterone (50 μmol. L-1).RESULTS: Progesterone decreased the resting tension of fundus and body longitudinal muscle (LM) (P＜0.05). It inhibited the mean contractile amplitude of body and antrum LM and circular muscle (CM), and the motility index of pyloric CM (P＜0.05). The inhibition of progesterone on the mean contractile amplitude could be partially blocked by phentolamine in LM of the stomach body (the mean contractile amplitude of body LM decreased from -7.5±5.5to -5.2±4.5 P＜0.01), and by phentolamine or indomethacin in CM of body (The inhibition of progesterone on the mean contractile amplitude of body CM decreased from -5.6±3.0to -3.6±2.7 by phentolamine and from -5.6±3.0 to -3.5±2.5by indomethacin, P＜0.01). Hexamethonium, propranolol and L-NNA (inhibitor of NO synthetase) didn′t affect the action of progesterone (P＞0.05).CONCLUSION: The study suggested that progesterone can inhibit the contractile activity of isolated gastric strips in rats and the mechanism seems to be a direct one except that the action on gastric body is mediated through prostaglandin and adrenergic α receptor partly.
文摘AIM: Activation of glial metabotropic glutamate receptors (mGluRs) may be proved to play a critical role for neuroprotection in neurodegenerative diseases. Excess glutamate induced-excitoxicity is implicated in the initiation or progression of the neurodegenerative process. Glutamate accumulation in the central nervous system mediated by inhibiting
基金Supported by the National Natural Science Foundation of China, No. 10335050Ministry of Science and Technology of the People's Republic of China, No. 2003CCB00200
文摘AIM:To investigate the radiation response of various human tumor cells and normal liver cells. METHODS: Cell lines of human hepatoma cells (SMMC-7721), liver cells (L02), melanoma cells (A375) and cervical tumor (HeLa) were irradiated with 60Co γ-rays. Cell survive was documented by a colony assay. Chromatid breaks were measured by counting the number of chromatid breaks and isochromatid breaks immediately after prematurely chromosome condensed by Calyculin-A. RESULTS: Linear quadratic survival curve was observed in all of four cell lines, and dose-dependent increase in radiation-induced chromatid and isochromatid breaks were observed in GB2B phase. Among these four cell lines, A375 was most sensitive to radiation, while, L02 had the lowest radiosensitivity. For normal liver cells, chromatid breaks were easy to be repaired, isochromatid breaks were difficult to be repaired. CONCLUSION: The results suggest that the y-rays induced chromatid breaks can be possibly used as a good predictor of radiosensitivity, also, unrejoined isochromatid breaks probably tightly related with cell cancerization.
文摘To test the accuracy of real-time three-dimensional echocardiography (RT3DE) imaging system for evaluating left ventricular mass (LVM) in phantom and excised canine heart. Methods Ten left ventricular (LV) wall phantoms made of two rubber-bursas, ten excised canine hearts underwent RT3DE and two-dimensional echocardiography (2DE). In RT3DE "full volume" imaging, the myocardial volume was mea-sured using 2,4,8, and 16-plane method with the analysis software of RT3DE. Mass was then calculated by multiplying the resulting myocardial volume by specific density of myocardial tissue. In 2DE the masses were measured by area-length meth-od. The true LV wall phantom mass was measured by water displacement and the canine LVM was weighed by anatomy, which served as a reference standard. We compared RT3DE or 2DE with true mass. Results In LV wall phantoms, RT3DE correlated with true masses strongly (r = 0.813-0.994) and weakly correlated between 2DE and true masses (r = 0.628). In excised canine hearts, there is an excellent correlation between RT3DE and true masses (r = 0.764-0.991), while 2DE value showed a lesser correlation (r = 0.514). There are no difference between RT-3DE and true masses (P > 0.05) but different between 2DE and true masses (P < 0.05). In different planes, there was no difference between 8-plane and 16-plane (P > 0.05) but different between 8-plane and 2, 4-plane (P < 0.05). Conclusion RT3DE can accurately quantify LVM and provide a new tool to evaluate LV function. For LVM by RT3DE, 8-plane measurement method is the best choice for accuracy and convenience.
