Objective Statins inhibit hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase activity and lower total serum cholesterol levels. We investigated the effects of Pravastatin on neuroprotection and neurogenesis in the...Objective Statins inhibit hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase activity and lower total serum cholesterol levels. We investigated the effects of Pravastatin on neuroprotection and neurogenesis in the dentate gyrus (DG), subventricular zone (SVZ) and striatum after cerebral ischemia in rats. Methods The filament method was used for temporary middle cerebral artery occlusion (tMCAO). Pravastatin or saline post-ischemically were administered at subsequent time points: 6 h after tMCAO, and then on every subsequent day up to day 14 after tMCAO. Neurological outcome was investigated by using a neuroscore, the beam balance test and the rotarod test. Cholesterol and triglycerides levels were determined by blood sample analysis prior to sacrifice. Infarct area was calculated by microtubule-associated protein 2 (MAP2) staining. Neurogenesis was evaluated by triple staining with bromodeoxyuridine (BrdU), doublecortin (DCX), and neuronal nuclei (NeuN). Results Compared with the control groups, Pravastatin treated animals were significantly improved in neurological outcome in rotarod test, with smaller infarct size. Pravastatin increased BrdU- positive cells number in the DG (P = 0.0029) and the SVZ (P = 0.0280) but not in the striatum (P = 0.3929). Furthermore, Pravastatin increased BrdU-labeled DCX positive cells number in the DG (P = 0.0031), SVZ (P = 0.0316) and striatum (P = 0.0073). We also observed a DCX-positive cells stream from the SVZ to the striatum, suggesting a migration route of those immature neurons. No significant differences of total serum cholesterol and triglycerides were observed between groups. Conclusion The Pravastatin administration strategy is safe and could promote neurological recovery in ischemic stroke. Pravastatin induces neurogenesis in the DG and SVZ, and increases the number of migration cells in the striatum. These effects are independent of the cholesterol-lowering property of Pravastatin.展开更多
Aim To synthesize dutasteride. Methods The target compound was synthesized from pregnenolol via eight steps, including esterification, oxidation, hydrolysis, then oxidative ring-opening, cyclization, reduction, oxidiz...Aim To synthesize dutasteride. Methods The target compound was synthesized from pregnenolol via eight steps, including esterification, oxidation, hydrolysis, then oxidative ring-opening, cyclization, reduction, oxidization and finally acylation. Results The structure of the target molecule was identified by ^1H NMR, ^13C NMR and element analysis. The overall yield was 31.5%. Conclusion The effects of different reaction conditions on the yield of product in each step have been investigated and the optimal reaction conditions have been established.展开更多
Supported and colloidal single‐atom catalysts(SACs),which possess excellent catalytic properties,are particularly important in both fundamental studies and practical applications.The progress made in the preparation ...Supported and colloidal single‐atom catalysts(SACs),which possess excellent catalytic properties,are particularly important in both fundamental studies and practical applications.The progress made in the preparation methods,characterization,catalytic performances and mechanisms of SACs anchored to metal oxides,two‐dimensional materials and the surface of metal nanoclusters(NCs)are reviewed.The different techniques for SAC fabrication,including conventional solution methods based on co‐precipitation,incipient wetness co‐impregnation,and the chemical vapor deposition method,as well as the newer atom layer deposition(ALD)and galvanic replacement methods,are summarized.The main results from experimental and theoretical studies of various catalytic reactions over SACs,including oxidation reactions,hydrogenation,water gas shift,photocatalytic H2evolution and electrochemical reactions,are also discussed.Moreover,the electronic properties of the single atoms and their interactions with the supports are described to assist in understanding the origin of the high catalytic activity and selectivity of SACs.Finally,possible future research directions of SACs and their applications are proposed.展开更多
AIM: To identify the role of herbal compound 861 (Cpd 861) in the regulation of mRNA expression of collagen synthesis- and degradation-related genes in human hepatic stellate cells (HSCs). METHODS: mRNA levels o...AIM: To identify the role of herbal compound 861 (Cpd 861) in the regulation of mRNA expression of collagen synthesis- and degradation-related genes in human hepatic stellate cells (HSCs). METHODS: mRNA levels of collagen types I and III, matrix metalloproteinase 1 (MMP-1), matrix metalloproteinase 2 (MMP-2), membrane type-1 matrix metalloproteinase (MT1-MMP), tissue inhibitor of metalloproteinase 1 (TIMP-1), and transforming growth factor β1 (TGF-β1) in cultured-activated HSCs treated with Cpd 861 or interferon-γ, (IFN-γ,) were determined by real-time PCR. RESULTS: Both Cpd 861 and IFN-γ reduced the mRNA levels of collagen type Ⅲ, MMP-2 and TGF-β1. Moreover, Cpd 861 significantly enhanced the MMP-1 mRNA levels while down-regulated the TIMP-1 mRNA expression, increasing the ratio of MMP-1 to TIMP-1 to (6.3 + 0.3)- fold compared to the control group. CONCLUSION: The anti-fibrosis function of Cpd 861 may be mediated by both decreased interstitial collagen sythesis by inhibiting the transcription of collagen type Ⅲ and TGF-β1 and increased degradation of these collagens by up-regulating MMP-1 and down-regulating TIMP-1 mRNA levels.展开更多
Objective. To measure the circulating levels of thrombomodulin (TM) and plasminogen activator inhibitor type- I (PAI- I) in women with pregnancy induced hypertension (PIH). Methods. Blood samples were drawn from 97 pr...Objective. To measure the circulating levels of thrombomodulin (TM) and plasminogen activator inhibitor type- I (PAI- I) in women with pregnancy induced hypertension (PIH). Methods. Blood samples were drawn from 97 pregnant women in their third trimester, grouped as 25 mild PIH,26 moderate PIH,22 severe PIH and 24 normotensive healthy pregnant women for determining levels of TM by ELISA,PAI- I by colorimetric assay methods, and creatinine (Cr) in serum by biochemical method. Results. Circulating levels of TM, PAI- I and TM/Cr ratio increased with increasing severity of PIH. There were no significant differences between mild and normotensive pregnant women. The parameters were significantly changed in the moderate and severe PIH groups. Conclusion. TM and PAI- I may serve as meaningful clinical markers for the assessment of the endothelial damage in PIH, which is very important in evaluating and following the development of PIH.展开更多
Bismuth tungstate(Bi_(2)WO_(6))has become a research hotspot due to its potential in photocatalytic energy conversion and environmental purification.Nevertheless,the limited light absorption and fast recombination of ...Bismuth tungstate(Bi_(2)WO_(6))has become a research hotspot due to its potential in photocatalytic energy conversion and environmental purification.Nevertheless,the limited light absorption and fast recombination of photogenerated carriers hinder the further improvement of the photocatalytic performance of Bi_(2)WO_(6).Herein,we provide a systematic review for the recent advances on Bi_(2)WO_(6)‐based photocatalysts.It starts with the crystal structure,optical properties and photocatalytic fundamentals of Bi_(2)WO_(6).Then,we focus on the modification strategies of Bi_(2)WO_(6)based on morphology control,atomic modulation and composite fabrication for diverse photocatalytic applications,such as organic synthesis,water splitting,CO2 reduction,water treatment,air purification,bacterial inactivation,etc.Finally,some current challenges and future development prospects are proposed.We expect that this review can provide a useful reference and guidance for the development of efficient Bi_(2)WO_(6)photocatalysts.展开更多
Simvastatin,a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor,is widely prescribed to patients with hypercholesteremia and its muscular toxicity has been widely reported.The metabolism of simvastatin depends...Simvastatin,a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor,is widely prescribed to patients with hypercholesteremia and its muscular toxicity has been widely reported.The metabolism of simvastatin depends on the enzymic activity of cytochrome P450 3A4 (CYP3A4) and inhibitors of CYP3A4 can result in clinical events by interacting with simvastatin.Diltiazem is a moderate inhibitor of CYP3A4,which is known to increase the serum concentration of simvastatin.Here we report a patient with unrecognized hypothyroidism who had been stable for more than one year on low-dose simvastatin therapy of hypercholesteremia and rhabdomyolysis occurred with the addition of diltiazem.This is one of scanty reports of rhabdomyolysis induced by simvastatindiltiazem drug interaction,especially in hypothyroid patient.This case reminds the clinicians that although diltiazem as a moderate CYP3A4 inhibitor can be used cautiously with small doses of CYP3A4-dependent statius (eg,simvastatin),these two commonly used drugs should be avoided in hypothyroid patient.展开更多
AIM: To predict the HLA-A2-restricted CTL epitopes of tumor antigens associated with hepatocellular carcinoma (HCC).METHODS: MAGE-1, MAGE-3, MAGE-8, P53 and AFP were selected as objective antigens in this study for th...AIM: To predict the HLA-A2-restricted CTL epitopes of tumor antigens associated with hepatocellular carcinoma (HCC).METHODS: MAGE-1, MAGE-3, MAGE-8, P53 and AFP were selected as objective antigens in this study for the close association with HCC. The HLA-A*0201 restricted CTL epitopes of objective tumor antigens were predicted by SYFPEITHI prediction method combined with the polynomial quantitative motifs method. The threshold of polynomial scores was set to -24.RESULTS: The SYFPEITHI prediction values of all possible nonamers of a given protein sequence were added together and the ten high-scoring peptides of each protein were chosen for further analysis in primary prediction. Thirtyfive candidates of CTL epitopes (nonamers) derived from the primary prediction results were selected by analyzing with the polynomial method and compared with reported CTL epitopes.CONCLUSION: The combination of SYFPEITHI prediction method and polynomial method can improve the prediction efficiency and accuracy. These nonamers may be useful in the design of therapeutic peptide vaccine for HCC and as immunotherapeutic strategies against HCC after identified by immunology experiment.展开更多
Triangular silver nanoplates in aqueous solvent and on the surface of quartz substrate have been synthesized by seed-mediated growth approach in the presence of tannin.It was found that both the amount of tannin and t...Triangular silver nanoplates in aqueous solvent and on the surface of quartz substrate have been synthesized by seed-mediated growth approach in the presence of tannin.It was found that both the amount of tannin and the small triangular silver nanoplate seeds added to the growth solution are the key factors to modulation absorption band of triangular silver nanoplates.The optical in-plane dipole surface plasmon resonance (SPR) bands of these Ag nanoplates can be tuned from 608 nm to 980 nm via tannin deoxidization method.The formation mechanism of triangular silver nanoplates was proposed.The tannin deoxidization method realizes a convenient modulation of the absorption band of Ag nanostructures within the visible near-infrared (IR) region both in aqueous solvent and on substrates under mild conditions.展开更多
Objective.To investigate the effect of peroxis ome proliferator-activated recept ors(PPARs )activators on plasminogen activator inhibitor ty pe-1(PAI-1)expression in human umbilical vein e ndothelial cells and the pos...Objective.To investigate the effect of peroxis ome proliferator-activated recept ors(PPARs )activators on plasminogen activator inhibitor ty pe-1(PAI-1)expression in human umbilical vein e ndothelial cells and the possi-ble mechanism.Methods.Human umbilical vein endothelial ce lls(HUVECs )were obtained from normal fetus,and cul-tured conventionally.Then the HUVECs were exposed to test agents(linolenic acid,linoleic acid,oleic acid,stearic acid and prostaglandin J 2 respectively)in varying concentrations with fresh media.RT -PCR and ELISA were applied to determine the expression of PPARs and PAI-1in HUVECs.Results.PPARα,PPARδand PPARγmRNA were detected by using RT-PCR in HUVECs.Treatment of HUVECs with PPARαand PPARγactivators---linolenic acid,linoleic acid,oleic acid and prostaglandin J 2 respectively,but not with stearic a cid could augment PAI-I mRNA expression and protein secretion in a concentration-dependent manner.However,the mRNA expressions of 3subclasses of PPAR with their activators in HUVECs were not changed compared w ith controls.Conclusion.HUVECs express PPARs.PPARs activators may increase PAI-1expression in ECs,but the underlying mechanism remains uncle ar.Although PPARs expression was not enhanced after stimulated by their activators in ECs,the role of functionally active PPARs in regulating PA I-1expression in ECs needs to be further investigated by using transient gen e transfection assay.展开更多
Using the JQ-II high pressure hydrogenation micro-reactor unit, the reactivity of Athabasca bitumen derived heavy gas oil was studied over commercial and homemade hydrotreating catalysts. The effects of catalyst prepa...Using the JQ-II high pressure hydrogenation micro-reactor unit, the reactivity of Athabasca bitumen derived heavy gas oil was studied over commercial and homemade hydrotreating catalysts. The effects of catalyst preparation variables and the influences of operation conditions, such as pressure, temperature, hydrogen/oil ratio and space velocity were also examined. It was shown that the optimal concentrations of the active components were 5% of NiO, 20% of MoO3 and 3.5% of phosphorus (by mass), and the suitable operation conditions were determined experimentally.展开更多
The therapeutic indications of 3-hydroxy-3-methylgl-utaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) include hypercholesterolaemia and the pre-vention of cardiovascular events. Statins are well toler-ate...The therapeutic indications of 3-hydroxy-3-methylgl-utaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) include hypercholesterolaemia and the pre-vention of cardiovascular events. Statins are well toler-ated and beyond their unambiguous positive cardio-vascular effects there are a steadily increasing number of pleiotropic actions emerging. In this regard, growth inhibition, apoptosis, anti-infammatory and immuno-modulatory actions have been attributed to statins. The anti-proliferative effects have been the basis for massive preclinical investigations to elucidate a func-tional role for statins in carcinogenesis and tumor cell growth. However, preclinical and clinical studies are conflicting, although there is accumulating evidence that statins are capable to suppress and decrease the incidence and recurrence of some human cancers. Giv-en the fact that statins are well tolerated they might also have some impact in combinations with conven-tional and targeted chemotherapy. While synergism has been shown for many combinations in vitro this does not hold true yet in the clinics. Here we review the rational behind usage of statins in oncological set-tings. Positive effects have been observed in patients with melanoma and cancers from the breast, colon, prostate, lung, liver and hematologic tissues. However, substantial evidence from clinical studies is still weak and confounded by several factors, which are inherent in the study design. The majority of the studies are ob-servational or of retrospective nature. Defnitely, there is substantial need for larger, prospective randomized, placebo-controlled trials. Finally, we conclude that statins at the current status of evidence should not be recommended in the prevention or during progression of any cancers, however, individual statins may have benefcial effects in specifc tumor subgroups.展开更多
Protoporphyrinogen oxidase inhibitor has become the focus research field as herbicides.Seven novel N-benzoxazolonyluracils were obtained by cyclization of 6-aminobenzoxazolone derivatives with ethyl 3-dimethylcarbamoy...Protoporphyrinogen oxidase inhibitor has become the focus research field as herbicides.Seven novel N-benzoxazolonyluracils were obtained by cyclization of 6-aminobenzoxazolone derivatives with ethyl 3-dimethylcarbamoylamido-4,4,4-trifluorocrotonate and then methylation or amination, and the reaction yields were between 5900—8600. The chemical structures of the compounds were identified by Elemental Analysis, MS and 1H NMR. Biological results indicate that some compounds exhibit excellent control of broadleaf weeds at post-emergence by low dosage 18.75 ga.i/ha, but are not effective for grass weeds below dosage 37.5 ga.i/ha. In addition, these compounds show no damage at high-dosage 150 ga.i/ha to wheat and corn, but are unsafe to dicotyledonous plants such as cole, soybean and sorghum even at lower dosage 18.75 ga.i/ha.展开更多
Atomic layer deposition(ALD)attracts great attention nowadays due to its ability for designing and modifying catalytic systems at the molecular level.There are several reported review papers published recently discuss...Atomic layer deposition(ALD)attracts great attention nowadays due to its ability for designing and modifying catalytic systems at the molecular level.There are several reported review papers published recently discussing this technique in catalysis.However,the mechanism on how the deposited materials improve the catalyst stability and tune the reaction selectivity is still unclear.Herein,catalytic systems created via ALD on stepwise preparation and/or modification under self-limiting reaction conditions are summarized.The effects of deposited materials in terms of electronic/geometry modification over the catalytic nanoparticles(NPs)are discussed.These effects explain the mechanism of the catalytic stability improvement and the selectivity modification.The unique properties of ALD for designing new catalytic systems are further investigated for building up photocatalytic reaction nanobowls,tandem catalyst and bi-active-component metallic catalytic systems.展开更多
AIM:Matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) are central to the spontaneous resolution of liver fibrosis. The mechanisms involved have been investigated in hepatic...AIM:Matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) are central to the spontaneous resolution of liver fibrosis. The mechanisms involved have been investigated in hepatic stellate cells (HSC), but not in hepatocytes. We investigated the effects of fibril- and fixed-collagen on MMP-1 and TIMP-1 production in hepatocytes, using the HLE cell line. METHODS: Fibril type I and IV collagen were prepared by HCI digestion of type I and IV collagen, respectively. For fixed-collagen, culture dishes were coated with fibril type I or IV collagen and fixed by ultraviolet. Type I collagenase activity was measured using fluorescein isothiocyanate-labeled type I collagen. MMP-1 and TIMP-1 in HLE cells were measured by a one-step sandwich enzyme immunoassay. RESULTS: Both fibril type I and IV collagen significantly increased type I collagenase activity about two-fold compared with no fibril collagen. The effects of the fibril collagen were not affected by the coating condition. There was no significant difference in the effects on collagenase activity between cells cultured in medium containing fibril type I collagen and those cultured in the presence of type IV collagen. Both types of fibril collagen significantly increased MMP-1 production, and showed more than 10-fold higher levels of MMP-1 than the control. The enhanced MMP-1 production by fibril collagens was unaffected by the coating condition. By contrast, TIMP-1 production was not changed by the addition of fibril type I or IV collagen, and neither was it affected by the coating conditions. Coating with type I collagen significantly suppressed MMP-1 production by almost one-tenth compared with no coating. By contrast, TIMP-1 production was not affected by either the absence of a collagen coat or by increasing the concentration of the coating collagen. CONCLUSION: These results indicated that, in HLE cells, fibril- and fixed-collagen have opposite effects on MMP-1 production without affecting TIMP production. Fibril collagen induced collagenase activity by up-regulation of MMP-1 production without affecting TIMP-1 production. By contrast, fixed collagen reduced MMP-1 production. Our results suggest that hepatocytes might also play an important role in the regulation of the hepatic fibrosis alongside HSC.展开更多
文摘Objective Statins inhibit hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase activity and lower total serum cholesterol levels. We investigated the effects of Pravastatin on neuroprotection and neurogenesis in the dentate gyrus (DG), subventricular zone (SVZ) and striatum after cerebral ischemia in rats. Methods The filament method was used for temporary middle cerebral artery occlusion (tMCAO). Pravastatin or saline post-ischemically were administered at subsequent time points: 6 h after tMCAO, and then on every subsequent day up to day 14 after tMCAO. Neurological outcome was investigated by using a neuroscore, the beam balance test and the rotarod test. Cholesterol and triglycerides levels were determined by blood sample analysis prior to sacrifice. Infarct area was calculated by microtubule-associated protein 2 (MAP2) staining. Neurogenesis was evaluated by triple staining with bromodeoxyuridine (BrdU), doublecortin (DCX), and neuronal nuclei (NeuN). Results Compared with the control groups, Pravastatin treated animals were significantly improved in neurological outcome in rotarod test, with smaller infarct size. Pravastatin increased BrdU- positive cells number in the DG (P = 0.0029) and the SVZ (P = 0.0280) but not in the striatum (P = 0.3929). Furthermore, Pravastatin increased BrdU-labeled DCX positive cells number in the DG (P = 0.0031), SVZ (P = 0.0316) and striatum (P = 0.0073). We also observed a DCX-positive cells stream from the SVZ to the striatum, suggesting a migration route of those immature neurons. No significant differences of total serum cholesterol and triglycerides were observed between groups. Conclusion The Pravastatin administration strategy is safe and could promote neurological recovery in ischemic stroke. Pravastatin induces neurogenesis in the DG and SVZ, and increases the number of migration cells in the striatum. These effects are independent of the cholesterol-lowering property of Pravastatin.
文摘Aim To synthesize dutasteride. Methods The target compound was synthesized from pregnenolol via eight steps, including esterification, oxidation, hydrolysis, then oxidative ring-opening, cyclization, reduction, oxidization and finally acylation. Results The structure of the target molecule was identified by ^1H NMR, ^13C NMR and element analysis. The overall yield was 31.5%. Conclusion The effects of different reaction conditions on the yield of product in each step have been investigated and the optimal reaction conditions have been established.
基金supported by the National Natural Science Foundation of China(51472184 and 51472185)the Science and Technology Support Program of Hubei Province(2013BHE003)the Program for Innovative Teams of Outstanding Young and Middle-Aged Researchers in the Higher Education Institutions of Hubei Province(T201602)~~
文摘Supported and colloidal single‐atom catalysts(SACs),which possess excellent catalytic properties,are particularly important in both fundamental studies and practical applications.The progress made in the preparation methods,characterization,catalytic performances and mechanisms of SACs anchored to metal oxides,two‐dimensional materials and the surface of metal nanoclusters(NCs)are reviewed.The different techniques for SAC fabrication,including conventional solution methods based on co‐precipitation,incipient wetness co‐impregnation,and the chemical vapor deposition method,as well as the newer atom layer deposition(ALD)and galvanic replacement methods,are summarized.The main results from experimental and theoretical studies of various catalytic reactions over SACs,including oxidation reactions,hydrogenation,water gas shift,photocatalytic H2evolution and electrochemical reactions,are also discussed.Moreover,the electronic properties of the single atoms and their interactions with the supports are described to assist in understanding the origin of the high catalytic activity and selectivity of SACs.Finally,possible future research directions of SACs and their applications are proposed.
文摘AIM: To identify the role of herbal compound 861 (Cpd 861) in the regulation of mRNA expression of collagen synthesis- and degradation-related genes in human hepatic stellate cells (HSCs). METHODS: mRNA levels of collagen types I and III, matrix metalloproteinase 1 (MMP-1), matrix metalloproteinase 2 (MMP-2), membrane type-1 matrix metalloproteinase (MT1-MMP), tissue inhibitor of metalloproteinase 1 (TIMP-1), and transforming growth factor β1 (TGF-β1) in cultured-activated HSCs treated with Cpd 861 or interferon-γ, (IFN-γ,) were determined by real-time PCR. RESULTS: Both Cpd 861 and IFN-γ reduced the mRNA levels of collagen type Ⅲ, MMP-2 and TGF-β1. Moreover, Cpd 861 significantly enhanced the MMP-1 mRNA levels while down-regulated the TIMP-1 mRNA expression, increasing the ratio of MMP-1 to TIMP-1 to (6.3 + 0.3)- fold compared to the control group. CONCLUSION: The anti-fibrosis function of Cpd 861 may be mediated by both decreased interstitial collagen sythesis by inhibiting the transcription of collagen type Ⅲ and TGF-β1 and increased degradation of these collagens by up-regulating MMP-1 and down-regulating TIMP-1 mRNA levels.
文摘Objective. To measure the circulating levels of thrombomodulin (TM) and plasminogen activator inhibitor type- I (PAI- I) in women with pregnancy induced hypertension (PIH). Methods. Blood samples were drawn from 97 pregnant women in their third trimester, grouped as 25 mild PIH,26 moderate PIH,22 severe PIH and 24 normotensive healthy pregnant women for determining levels of TM by ELISA,PAI- I by colorimetric assay methods, and creatinine (Cr) in serum by biochemical method. Results. Circulating levels of TM, PAI- I and TM/Cr ratio increased with increasing severity of PIH. There were no significant differences between mild and normotensive pregnant women. The parameters were significantly changed in the moderate and severe PIH groups. Conclusion. TM and PAI- I may serve as meaningful clinical markers for the assessment of the endothelial damage in PIH, which is very important in evaluating and following the development of PIH.
文摘Bismuth tungstate(Bi_(2)WO_(6))has become a research hotspot due to its potential in photocatalytic energy conversion and environmental purification.Nevertheless,the limited light absorption and fast recombination of photogenerated carriers hinder the further improvement of the photocatalytic performance of Bi_(2)WO_(6).Herein,we provide a systematic review for the recent advances on Bi_(2)WO_(6)‐based photocatalysts.It starts with the crystal structure,optical properties and photocatalytic fundamentals of Bi_(2)WO_(6).Then,we focus on the modification strategies of Bi_(2)WO_(6)based on morphology control,atomic modulation and composite fabrication for diverse photocatalytic applications,such as organic synthesis,water splitting,CO2 reduction,water treatment,air purification,bacterial inactivation,etc.Finally,some current challenges and future development prospects are proposed.We expect that this review can provide a useful reference and guidance for the development of efficient Bi_(2)WO_(6)photocatalysts.
文摘Simvastatin,a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor,is widely prescribed to patients with hypercholesteremia and its muscular toxicity has been widely reported.The metabolism of simvastatin depends on the enzymic activity of cytochrome P450 3A4 (CYP3A4) and inhibitors of CYP3A4 can result in clinical events by interacting with simvastatin.Diltiazem is a moderate inhibitor of CYP3A4,which is known to increase the serum concentration of simvastatin.Here we report a patient with unrecognized hypothyroidism who had been stable for more than one year on low-dose simvastatin therapy of hypercholesteremia and rhabdomyolysis occurred with the addition of diltiazem.This is one of scanty reports of rhabdomyolysis induced by simvastatindiltiazem drug interaction,especially in hypothyroid patient.This case reminds the clinicians that although diltiazem as a moderate CYP3A4 inhibitor can be used cautiously with small doses of CYP3A4-dependent statius (eg,simvastatin),these two commonly used drugs should be avoided in hypothyroid patient.
基金Supported by Natural Scientific Foundation of China, No. 39830420
文摘AIM: To predict the HLA-A2-restricted CTL epitopes of tumor antigens associated with hepatocellular carcinoma (HCC).METHODS: MAGE-1, MAGE-3, MAGE-8, P53 and AFP were selected as objective antigens in this study for the close association with HCC. The HLA-A*0201 restricted CTL epitopes of objective tumor antigens were predicted by SYFPEITHI prediction method combined with the polynomial quantitative motifs method. The threshold of polynomial scores was set to -24.RESULTS: The SYFPEITHI prediction values of all possible nonamers of a given protein sequence were added together and the ten high-scoring peptides of each protein were chosen for further analysis in primary prediction. Thirtyfive candidates of CTL epitopes (nonamers) derived from the primary prediction results were selected by analyzing with the polynomial method and compared with reported CTL epitopes.CONCLUSION: The combination of SYFPEITHI prediction method and polynomial method can improve the prediction efficiency and accuracy. These nonamers may be useful in the design of therapeutic peptide vaccine for HCC and as immunotherapeutic strategies against HCC after identified by immunology experiment.
基金Project(10804101) supported by the National Natural Science Foundation of ChinaProject(2007CB815102) supported by the National Basic Research Program of ChinaProject(2007B08007) supported by the Science and Technology Development Foundation of Chinese Academy of Engineering Physics
文摘Triangular silver nanoplates in aqueous solvent and on the surface of quartz substrate have been synthesized by seed-mediated growth approach in the presence of tannin.It was found that both the amount of tannin and the small triangular silver nanoplate seeds added to the growth solution are the key factors to modulation absorption band of triangular silver nanoplates.The optical in-plane dipole surface plasmon resonance (SPR) bands of these Ag nanoplates can be tuned from 608 nm to 980 nm via tannin deoxidization method.The formation mechanism of triangular silver nanoplates was proposed.The tannin deoxidization method realizes a convenient modulation of the absorption band of Ag nanostructures within the visible near-infrared (IR) region both in aqueous solvent and on substrates under mild conditions.
文摘Objective.To investigate the effect of peroxis ome proliferator-activated recept ors(PPARs )activators on plasminogen activator inhibitor ty pe-1(PAI-1)expression in human umbilical vein e ndothelial cells and the possi-ble mechanism.Methods.Human umbilical vein endothelial ce lls(HUVECs )were obtained from normal fetus,and cul-tured conventionally.Then the HUVECs were exposed to test agents(linolenic acid,linoleic acid,oleic acid,stearic acid and prostaglandin J 2 respectively)in varying concentrations with fresh media.RT -PCR and ELISA were applied to determine the expression of PPARs and PAI-1in HUVECs.Results.PPARα,PPARδand PPARγmRNA were detected by using RT-PCR in HUVECs.Treatment of HUVECs with PPARαand PPARγactivators---linolenic acid,linoleic acid,oleic acid and prostaglandin J 2 respectively,but not with stearic a cid could augment PAI-I mRNA expression and protein secretion in a concentration-dependent manner.However,the mRNA expressions of 3subclasses of PPAR with their activators in HUVECs were not changed compared w ith controls.Conclusion.HUVECs express PPARs.PPARs activators may increase PAI-1expression in ECs,but the underlying mechanism remains uncle ar.Although PPARs expression was not enhanced after stimulated by their activators in ECs,the role of functionally active PPARs in regulating PA I-1expression in ECs needs to be further investigated by using transient gen e transfection assay.
文摘Using the JQ-II high pressure hydrogenation micro-reactor unit, the reactivity of Athabasca bitumen derived heavy gas oil was studied over commercial and homemade hydrotreating catalysts. The effects of catalyst preparation variables and the influences of operation conditions, such as pressure, temperature, hydrogen/oil ratio and space velocity were also examined. It was shown that the optimal concentrations of the active components were 5% of NiO, 20% of MoO3 and 3.5% of phosphorus (by mass), and the suitable operation conditions were determined experimentally.
基金Supported by The Herzfeldersche Familienstiftung and the Austrian Science foundation,FWF-Project P22385
文摘The therapeutic indications of 3-hydroxy-3-methylgl-utaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) include hypercholesterolaemia and the pre-vention of cardiovascular events. Statins are well toler-ated and beyond their unambiguous positive cardio-vascular effects there are a steadily increasing number of pleiotropic actions emerging. In this regard, growth inhibition, apoptosis, anti-infammatory and immuno-modulatory actions have been attributed to statins. The anti-proliferative effects have been the basis for massive preclinical investigations to elucidate a func-tional role for statins in carcinogenesis and tumor cell growth. However, preclinical and clinical studies are conflicting, although there is accumulating evidence that statins are capable to suppress and decrease the incidence and recurrence of some human cancers. Giv-en the fact that statins are well tolerated they might also have some impact in combinations with conven-tional and targeted chemotherapy. While synergism has been shown for many combinations in vitro this does not hold true yet in the clinics. Here we review the rational behind usage of statins in oncological set-tings. Positive effects have been observed in patients with melanoma and cancers from the breast, colon, prostate, lung, liver and hematologic tissues. However, substantial evidence from clinical studies is still weak and confounded by several factors, which are inherent in the study design. The majority of the studies are ob-servational or of retrospective nature. Defnitely, there is substantial need for larger, prospective randomized, placebo-controlled trials. Finally, we conclude that statins at the current status of evidence should not be recommended in the prevention or during progression of any cancers, however, individual statins may have benefcial effects in specifc tumor subgroups.
文摘Protoporphyrinogen oxidase inhibitor has become the focus research field as herbicides.Seven novel N-benzoxazolonyluracils were obtained by cyclization of 6-aminobenzoxazolone derivatives with ethyl 3-dimethylcarbamoylamido-4,4,4-trifluorocrotonate and then methylation or amination, and the reaction yields were between 5900—8600. The chemical structures of the compounds were identified by Elemental Analysis, MS and 1H NMR. Biological results indicate that some compounds exhibit excellent control of broadleaf weeds at post-emergence by low dosage 18.75 ga.i/ha, but are not effective for grass weeds below dosage 37.5 ga.i/ha. In addition, these compounds show no damage at high-dosage 150 ga.i/ha to wheat and corn, but are unsafe to dicotyledonous plants such as cole, soybean and sorghum even at lower dosage 18.75 ga.i/ha.
基金supported by the U.S. Department of Energy, Office of Science, and Office of the Basic Energy Sciences, under Contract DE-AC-02-06CH11357~~
文摘Atomic layer deposition(ALD)attracts great attention nowadays due to its ability for designing and modifying catalytic systems at the molecular level.There are several reported review papers published recently discussing this technique in catalysis.However,the mechanism on how the deposited materials improve the catalyst stability and tune the reaction selectivity is still unclear.Herein,catalytic systems created via ALD on stepwise preparation and/or modification under self-limiting reaction conditions are summarized.The effects of deposited materials in terms of electronic/geometry modification over the catalytic nanoparticles(NPs)are discussed.These effects explain the mechanism of the catalytic stability improvement and the selectivity modification.The unique properties of ALD for designing new catalytic systems are further investigated for building up photocatalytic reaction nanobowls,tandem catalyst and bi-active-component metallic catalytic systems.
文摘AIM:Matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) are central to the spontaneous resolution of liver fibrosis. The mechanisms involved have been investigated in hepatic stellate cells (HSC), but not in hepatocytes. We investigated the effects of fibril- and fixed-collagen on MMP-1 and TIMP-1 production in hepatocytes, using the HLE cell line. METHODS: Fibril type I and IV collagen were prepared by HCI digestion of type I and IV collagen, respectively. For fixed-collagen, culture dishes were coated with fibril type I or IV collagen and fixed by ultraviolet. Type I collagenase activity was measured using fluorescein isothiocyanate-labeled type I collagen. MMP-1 and TIMP-1 in HLE cells were measured by a one-step sandwich enzyme immunoassay. RESULTS: Both fibril type I and IV collagen significantly increased type I collagenase activity about two-fold compared with no fibril collagen. The effects of the fibril collagen were not affected by the coating condition. There was no significant difference in the effects on collagenase activity between cells cultured in medium containing fibril type I collagen and those cultured in the presence of type IV collagen. Both types of fibril collagen significantly increased MMP-1 production, and showed more than 10-fold higher levels of MMP-1 than the control. The enhanced MMP-1 production by fibril collagens was unaffected by the coating condition. By contrast, TIMP-1 production was not changed by the addition of fibril type I or IV collagen, and neither was it affected by the coating conditions. Coating with type I collagen significantly suppressed MMP-1 production by almost one-tenth compared with no coating. By contrast, TIMP-1 production was not affected by either the absence of a collagen coat or by increasing the concentration of the coating collagen. CONCLUSION: These results indicated that, in HLE cells, fibril- and fixed-collagen have opposite effects on MMP-1 production without affecting TIMP production. Fibril collagen induced collagenase activity by up-regulation of MMP-1 production without affecting TIMP-1 production. By contrast, fixed collagen reduced MMP-1 production. Our results suggest that hepatocytes might also play an important role in the regulation of the hepatic fibrosis alongside HSC.