Poly[R-3-hydroxybutyrate-co-(R-3-hydroxyvalerate)] (PHBVs) copolymers are promising biopolymers, which could substitute petroleum-based plastics for various applications. PHB and PHBV pellets were processed on a custo...Poly[R-3-hydroxybutyrate-co-(R-3-hydroxyvalerate)] (PHBVs) copolymers are promising biopolymers, which could substitute petroleum-based plastics for various applications. PHB and PHBV pellets were processed on a customized 3D printer via Fused Granular Manufacturing (FGM) approach modified with a Mahor screw extruder. To anticipate the behaviour of PHBVs when transformed using conventional thermo-mechanical shaping processes, thermal and mechanical analyses were carried out in order to better understand the effect of annealing temperature on their crystallization behaviour and mechanical properties of PHB polymer and PHBV copolymer. The objectives of the present work were to propose an experimental strategy to study the melting and crystallization events, crystalline structure changes, and mechanical performances of both PHB homopolymer and PHBV copolymer according to identical thermal annealing treatments. A monitoring of 3D printed PHB and PHBV structures was achieved by coupling Differential Scanning Calorimetry (DSC) and tensile tests. .展开更多
Density functional theory（DFT） and time-dependent density functional theory（TDDFT） methods are used to investigate the influences of intramolecular and intermolecular hydrogen bonding on excited-state intramolecul...Density functional theory（DFT） and time-dependent density functional theory（TDDFT） methods are used to investigate the influences of intramolecular and intermolecular hydrogen bonding on excited-state intramolecular proton transfer（ESIPT） for the 4-N,N-（diethylamino）-2-hydroxybenzaldehyde（DEAHB）. The structures of DEAHB and its hydrogenbonded complex in the ground-state and the excited-state are optimized. In addition, the detailed descriptions of frontier molecular orbitals of the DEAHB monomer and DEAHB-DMSO complex are presented. Moreover, the transition density matrix is worked out to gain deeper insight into the orbitals change. It is hoped that the present work not only elaborates different influence mechanisms between intramolecular and intermolecular hydrogen bonding interactions on the ESIPT process for DEAHB, but also may be helpful to design and develop new materials and applications involved DEAHB systems in the future.展开更多
AIM: To explore the role of SF/HGF-Met autocrine and parscrine in metastasis of hepatocellular carcinoma (HCC).METHODS: SF/HGF and c-met transcription and protein expression in HCC were examined by RT-PCR and Western ...AIM: To explore the role of SF/HGF-Met autocrine and parscrine in metastasis of hepatocellular carcinoma (HCC).METHODS: SF/HGF and c-met transcription and protein expression in HCC were examined by RT-PCR and Western Blot in 4 HCC cell lines, including HepG2, Hep3B,SMMC7721 and MHCC-1, the last cell line had a higher potential of metastasis. Sf/hgf cDNA was transfected by the method of Lipofectin into SMMC7721. SF/HGF and c-met antibody were used to stimulate and block SF/HGF-c-met signal transduction. Cell morphology, mobility, and proliferation were respectively compared by microscopic observation, wound healing assay and cell growth curve.RESULTS: HCC malignancy appeared to be relative to its met-SF/HGF expression. In MHCC-1, c-met expression was much stronger than that in other cell lines with lower potential of metastasis and only SF/HGF autocrine existed in MHCC-1. After sf/hgf cDNA transfection or conditioned medium of MHCC-1 stimulation, SMMC7721 changed into elongated morphology, and the abilities of proliferation ( P < 0.05) and mobility increased. Such bio-activity could he blocked by c-met antibody ( P< 0.05).CONCLUSION: The system of SF/HGF-c-met autocrine and paracrine played an important role in development and metastasis potential of HCC. Inhibition of SF/HGF-c-met signal transduction system may reduce the growth and metastasis of HCC.展开更多
Background:Increasing understanding on the functions of amino acids (AA) has led to new commercial applications and expansion of the worldwide markets.However,the current technologies rely heavily on non-food grade mi...Background:Increasing understanding on the functions of amino acids (AA) has led to new commercial applications and expansion of the worldwide markets.However,the current technologies rely heavily on non-food grade microorganism and chemical synthesis for the production of AA.Several studies reported that lactic acid bacteria (LAB) have the capability of producing AA owing to their well-established proteolytic system and amino acid biosynthesis genes.Hence,the objectives of this study were to explore the extracellular proteolytic activity of LAB isolated from various Malaysian fermented foods and their potential to produce AA extracellularly as feed supplements.Results:All the studied LAB isolates were versatile extracellular protease producers,whereby extracellular protease activities were detected from acidic to alkaline pH (pH 5,pH 6.5,pH 8) using qualitative and quantitative proteolytic assays.The highest proteolytic activity at pH 5 (15.76 U/mg) and pH 8 (19.42 U/mg) was achieved by Lactobacillus plantarum RG14,while Lactobacillus plantarum RS5 exhibited the highest proteolytic activity of 17.22 U/mg at pH 6.5.As for the results of AA production conducted in de Man,Rogosa and Sharpe medium and analysed by high pressure liquid chromatography system,all LAB isolates were capable of producing an array of AA.Generally,Pediococcus sp.showed greater ability for AA production as compared to Lactobacillus sp.Moreover,the studied LAB were able to produce a few major feed supplement AA such as methionine,lysine,threonine and tryptophan.P.pentosaceus TL-3 recorded the highest methionine and threonine productivity of 3.72 mg/L/h and 5.58 mg/L/h respectively.However,L.plantarum I-UL4 demonstrated a lysine productivity of 1.24 mg/L/h,while P.acidilactici TP-6 achieved up to 1.73 mg/L/h of tryptophan productivity.Conclusion:All the 17 studied LAB isolates possessed versatile extracellular proteolytic system and have vast capability of producing various amino acids including a few major feed supplement AA such as methionine,lysine,threonine and tryptophan.Despite AA production was strain dependent,the studied LAB isolates possessed vast potential and can be exploited further as a bio-agent or an alternative amino acids and bioactive peptide producers.展开更多
Objective To investigate the influences of previous angina pectoris on coronary collateral circulation and left ventricular function in patients with acute myocardial infarction. Methods 307 patients with a first epis...Objective To investigate the influences of previous angina pectoris on coronary collateral circulation and left ventricular function in patients with acute myocardial infarction. Methods 307 patients with a first episode acute myocardial infarction underwent selective coronary angiography and left ventriculography. The relation of previous angina pectoris to coronary collateral circulation, peak creatine kinase and left ventricular function were analyzed. Results ①In the 307 patients, there were 192 (62. 5 % ) with previous angina [PA ( + ) group] and 115 (37. 5 % ) without [PA (-) group]. ②The peak creatine kinase (CK) and CK -MB were significantly higher in PA (-) group than in PA (+) group ( P < 0. 05 for both comparisons) . ③ Collateral circulation to infarct - related artery was more likely to be present in PA ( + ) group than in PA (-) group ( P < 0. 05) . (4) The left ventricular ejection fraction was significantly increased, and the left ventricular wall motion Cortina score decreased, in PA (+) group than in PA (-) group ( P < 0. 01 for both comparisons) . Conclusion In patients with acute myocardial infarction, previous angina pectoris may have beneficial effects on coronary collateral circulation and left ventricular function.展开更多
Purpose: To compare the short-term efficacy and side effects of betaxolol and timoloi in treatment of primary open angle glaucoma or ocular hypertension. Methods: Fourteen patients with newly diagnosed early primary o...Purpose: To compare the short-term efficacy and side effects of betaxolol and timoloi in treatment of primary open angle glaucoma or ocular hypertension. Methods: Fourteen patients with newly diagnosed early primary open angle glaucoma or ocular hypertension were included.Each patient received 0.5% timoloi and 0.5% betaxolol twice daily for four weeks in two phases. Between two courses of treatment there was four weeks wash out period. At the end of study the effect of these two drugs on intraocular pressure, mean arterial blood pressure,pulse rate,basic tear secretion and ocular symptoms were evaluated and statistically analyzed,using wilcoxon and chi-squar test.RESULTS:The study was performed on fourteen patients with baseline IOP of 26.7 ±1.5 mmHg.After four weeks treatmem,timoiol and betax-olol reduced IOP by 7.8±1.2mmHg or 29% and 6.1±1.3mmHg or 23%, respectively (P<0.001). The difference between two groups was significant(P<0.001). Mean arterial blood pressure was reduced with betaxolol and展开更多
The interactions between herbivores and their host plants play a key role in ecological processes. Understanding the width and nature of these interactions is funda- mental to ecology and conservation. Recent research...The interactions between herbivores and their host plants play a key role in ecological processes. Understanding the width and nature of these interactions is funda- mental to ecology and conservation. Recent research on DNA-based inference of trophic associations suggests that the host range of phytophagous insects in the tropics may be wider than previously thought based on traditional observation. However, the reliability of molecular inference of ecological associations, still strongly dependent on PCR and thus exposed to the risk of contamination with environmental DNA, is under debate. Here, we explored alternative procedures to reduce the chance of amplification of external, nondiet DNA, including surface decontamination and analysis of mid/hind guts, comparing the results with those obtained using the standard protocol. We studied 261 specimens in eight species of Neotropical Chrysomelidae that yielded 316 psbA-trnH intergenic spacer sequences （cpDNA marker of putative diets） from unique and multiple-band PCR results. The taxonomic identity of these sequences was inferred using the automated pipeline BAGpipe, yielding results consistent with 31 plant families. Regardless of the proto- col used, a wide taxonomic spectrum of food was inferred for all chrysomelid species. Canonical Correspondence Analysis using these data revealed significant differences at- tributed mainly to species （expectedly, since they represent different ecologies）, but also to treatment （untreated vs. cleaned/gut samples） and PCR results （single vs. multiple bands）. Molecular identification of diets is not straightforward and, regardless of the species＇ niche breadth, combining approaches that reduce external contamination and studying multiple individuals per species may help increasing confidence in results.展开更多
Hepatocellular carcinoma(HCC)is the fifth most common cancer and the third most common cause of cancer-related deaths worldwide.Curative resection is frequently limited in Hong Kong by hepatitis B virus-related cirrho...Hepatocellular carcinoma(HCC)is the fifth most common cancer and the third most common cause of cancer-related deaths worldwide.Curative resection is frequently limited in Hong Kong by hepatitis B virus-related cirrhosis,and liver transplantation is the treatment of choice.Liver transplanta-tion has been shown to produce superior oncological benefits,when compared to hepatectomy for HCC.New developments in the context of patient selection criteria,modification of organ allocation,bridging therapy,salvage liver transplanta-tion and pharmaceutical breakthrough have improved the survival of HCC patients.In this article,we will share our experience in transplanting hepatitis B virus-related HCC patients in Hong Kong and discuss the recent progress in several areas of liver transplantation.展开更多
The composite tumors of the liver are very rare,including the coexistence of HCC(hepatocellular carcinoma)with NEC(neuroendocrine carcinoma).The rare occurrence of these tumors necessitates more reported cases in orde...The composite tumors of the liver are very rare,including the coexistence of HCC(hepatocellular carcinoma)with NEC(neuroendocrine carcinoma).The rare occurrence of these tumors necessitates more reported cases in order to fully understand their clinical characteristics,behaviors and treatments.Herein is described an incidental collision tumor of HCC-NEC,along with a review of the literature focusing on their clinicopathological findings and prognosis.The tumor presented here was found incidentally in the hepatectomy specimen of a 56-yearold man who had undergone liver transplantation for rapidly progressive liver failure because of alcoholic hepatitis and cirrhosis.Imaging and laboratory examinations did not demonstrate tumor-related findings.During macroscopic examination,two sharply defined and distinctive areas(1.7 cm and 0.6 cm dimension respectively)were detected among the cirrhotic nodules.The characteristic histopathological features and immunohistochemical findings allowed a diagnosis of HCCNEC to be made.There was no evidence of recurrence and metastasis after 10months following surgery.The present case and review revealed that these tumors are frequently found in older ages and males.Although serum markers are valuable in the discrimination of malignant tumors,their absence cannot completely rule out composite HCC-NEC.Diagnosis requires a comprehensive histopathological evaluation together with immunohistochemistry.The NEC component might influence the treatment strategy and eventually the outcome of the patient.In conclusion,the rare occurrence of HCC-NEC and the lack of diagnostic clinical signs and symptoms do not exclude their consideration in the differential diagnosis of liver tumors,especially in patients with the chronic liver disease.展开更多
文摘Poly[R-3-hydroxybutyrate-co-(R-3-hydroxyvalerate)] (PHBVs) copolymers are promising biopolymers, which could substitute petroleum-based plastics for various applications. PHB and PHBV pellets were processed on a customized 3D printer via Fused Granular Manufacturing (FGM) approach modified with a Mahor screw extruder. To anticipate the behaviour of PHBVs when transformed using conventional thermo-mechanical shaping processes, thermal and mechanical analyses were carried out in order to better understand the effect of annealing temperature on their crystallization behaviour and mechanical properties of PHB polymer and PHBV copolymer. The objectives of the present work were to propose an experimental strategy to study the melting and crystallization events, crystalline structure changes, and mechanical performances of both PHB homopolymer and PHBV copolymer according to identical thermal annealing treatments. A monitoring of 3D printed PHB and PHBV structures was achieved by coupling Differential Scanning Calorimetry (DSC) and tensile tests. .
基金Project supported by the National Basic Research Program of China(Grant No.2013CB922204)the National Natural Science Foundation of China(Grant Nos.11574115 and 11704146)
文摘Density functional theory（DFT） and time-dependent density functional theory（TDDFT） methods are used to investigate the influences of intramolecular and intermolecular hydrogen bonding on excited-state intramolecular proton transfer（ESIPT） for the 4-N,N-（diethylamino）-2-hydroxybenzaldehyde（DEAHB）. The structures of DEAHB and its hydrogenbonded complex in the ground-state and the excited-state are optimized. In addition, the detailed descriptions of frontier molecular orbitals of the DEAHB monomer and DEAHB-DMSO complex are presented. Moreover, the transition density matrix is worked out to gain deeper insight into the orbitals change. It is hoped that the present work not only elaborates different influence mechanisms between intramolecular and intermolecular hydrogen bonding interactions on the ESIPT process for DEAHB, but also may be helpful to design and develop new materials and applications involved DEAHB systems in the future.
基金Supported by Natural Science Foundation of China No.39970290
文摘AIM: To explore the role of SF/HGF-Met autocrine and parscrine in metastasis of hepatocellular carcinoma (HCC).METHODS: SF/HGF and c-met transcription and protein expression in HCC were examined by RT-PCR and Western Blot in 4 HCC cell lines, including HepG2, Hep3B,SMMC7721 and MHCC-1, the last cell line had a higher potential of metastasis. Sf/hgf cDNA was transfected by the method of Lipofectin into SMMC7721. SF/HGF and c-met antibody were used to stimulate and block SF/HGF-c-met signal transduction. Cell morphology, mobility, and proliferation were respectively compared by microscopic observation, wound healing assay and cell growth curve.RESULTS: HCC malignancy appeared to be relative to its met-SF/HGF expression. In MHCC-1, c-met expression was much stronger than that in other cell lines with lower potential of metastasis and only SF/HGF autocrine existed in MHCC-1. After sf/hgf cDNA transfection or conditioned medium of MHCC-1 stimulation, SMMC7721 changed into elongated morphology, and the abilities of proliferation ( P < 0.05) and mobility increased. Such bio-activity could he blocked by c-met antibody ( P< 0.05).CONCLUSION: The system of SF/HGF-c-met autocrine and paracrine played an important role in development and metastasis potential of HCC. Inhibition of SF/HGF-c-met signal transduction system may reduce the growth and metastasis of HCC.
基金The Long-Term Research Grant(LRGS)of the Ministry of Education of Malaysia supported this work
文摘Background:Increasing understanding on the functions of amino acids (AA) has led to new commercial applications and expansion of the worldwide markets.However,the current technologies rely heavily on non-food grade microorganism and chemical synthesis for the production of AA.Several studies reported that lactic acid bacteria (LAB) have the capability of producing AA owing to their well-established proteolytic system and amino acid biosynthesis genes.Hence,the objectives of this study were to explore the extracellular proteolytic activity of LAB isolated from various Malaysian fermented foods and their potential to produce AA extracellularly as feed supplements.Results:All the studied LAB isolates were versatile extracellular protease producers,whereby extracellular protease activities were detected from acidic to alkaline pH (pH 5,pH 6.5,pH 8) using qualitative and quantitative proteolytic assays.The highest proteolytic activity at pH 5 (15.76 U/mg) and pH 8 (19.42 U/mg) was achieved by Lactobacillus plantarum RG14,while Lactobacillus plantarum RS5 exhibited the highest proteolytic activity of 17.22 U/mg at pH 6.5.As for the results of AA production conducted in de Man,Rogosa and Sharpe medium and analysed by high pressure liquid chromatography system,all LAB isolates were capable of producing an array of AA.Generally,Pediococcus sp.showed greater ability for AA production as compared to Lactobacillus sp.Moreover,the studied LAB were able to produce a few major feed supplement AA such as methionine,lysine,threonine and tryptophan.P.pentosaceus TL-3 recorded the highest methionine and threonine productivity of 3.72 mg/L/h and 5.58 mg/L/h respectively.However,L.plantarum I-UL4 demonstrated a lysine productivity of 1.24 mg/L/h,while P.acidilactici TP-6 achieved up to 1.73 mg/L/h of tryptophan productivity.Conclusion:All the 17 studied LAB isolates possessed versatile extracellular proteolytic system and have vast capability of producing various amino acids including a few major feed supplement AA such as methionine,lysine,threonine and tryptophan.Despite AA production was strain dependent,the studied LAB isolates possessed vast potential and can be exploited further as a bio-agent or an alternative amino acids and bioactive peptide producers.
文摘Objective To investigate the influences of previous angina pectoris on coronary collateral circulation and left ventricular function in patients with acute myocardial infarction. Methods 307 patients with a first episode acute myocardial infarction underwent selective coronary angiography and left ventriculography. The relation of previous angina pectoris to coronary collateral circulation, peak creatine kinase and left ventricular function were analyzed. Results ①In the 307 patients, there were 192 (62. 5 % ) with previous angina [PA ( + ) group] and 115 (37. 5 % ) without [PA (-) group]. ②The peak creatine kinase (CK) and CK -MB were significantly higher in PA (-) group than in PA (+) group ( P < 0. 05 for both comparisons) . ③ Collateral circulation to infarct - related artery was more likely to be present in PA ( + ) group than in PA (-) group ( P < 0. 05) . (4) The left ventricular ejection fraction was significantly increased, and the left ventricular wall motion Cortina score decreased, in PA (+) group than in PA (-) group ( P < 0. 01 for both comparisons) . Conclusion In patients with acute myocardial infarction, previous angina pectoris may have beneficial effects on coronary collateral circulation and left ventricular function.
文摘Purpose: To compare the short-term efficacy and side effects of betaxolol and timoloi in treatment of primary open angle glaucoma or ocular hypertension. Methods: Fourteen patients with newly diagnosed early primary open angle glaucoma or ocular hypertension were included.Each patient received 0.5% timoloi and 0.5% betaxolol twice daily for four weeks in two phases. Between two courses of treatment there was four weeks wash out period. At the end of study the effect of these two drugs on intraocular pressure, mean arterial blood pressure,pulse rate,basic tear secretion and ocular symptoms were evaluated and statistically analyzed,using wilcoxon and chi-squar test.RESULTS:The study was performed on fourteen patients with baseline IOP of 26.7 ±1.5 mmHg.After four weeks treatmem,timoiol and betax-olol reduced IOP by 7.8±1.2mmHg or 29% and 6.1±1.3mmHg or 23%, respectively (P<0.001). The difference between two groups was significant(P<0.001). Mean arterial blood pressure was reduced with betaxolol and
文摘The interactions between herbivores and their host plants play a key role in ecological processes. Understanding the width and nature of these interactions is funda- mental to ecology and conservation. Recent research on DNA-based inference of trophic associations suggests that the host range of phytophagous insects in the tropics may be wider than previously thought based on traditional observation. However, the reliability of molecular inference of ecological associations, still strongly dependent on PCR and thus exposed to the risk of contamination with environmental DNA, is under debate. Here, we explored alternative procedures to reduce the chance of amplification of external, nondiet DNA, including surface decontamination and analysis of mid/hind guts, comparing the results with those obtained using the standard protocol. We studied 261 specimens in eight species of Neotropical Chrysomelidae that yielded 316 psbA-trnH intergenic spacer sequences （cpDNA marker of putative diets） from unique and multiple-band PCR results. The taxonomic identity of these sequences was inferred using the automated pipeline BAGpipe, yielding results consistent with 31 plant families. Regardless of the proto- col used, a wide taxonomic spectrum of food was inferred for all chrysomelid species. Canonical Correspondence Analysis using these data revealed significant differences at- tributed mainly to species （expectedly, since they represent different ecologies）, but also to treatment （untreated vs. cleaned/gut samples） and PCR results （single vs. multiple bands）. Molecular identification of diets is not straightforward and, regardless of the species＇ niche breadth, combining approaches that reduce external contamination and studying multiple individuals per species may help increasing confidence in results.
文摘Hepatocellular carcinoma(HCC)is the fifth most common cancer and the third most common cause of cancer-related deaths worldwide.Curative resection is frequently limited in Hong Kong by hepatitis B virus-related cirrhosis,and liver transplantation is the treatment of choice.Liver transplanta-tion has been shown to produce superior oncological benefits,when compared to hepatectomy for HCC.New developments in the context of patient selection criteria,modification of organ allocation,bridging therapy,salvage liver transplanta-tion and pharmaceutical breakthrough have improved the survival of HCC patients.In this article,we will share our experience in transplanting hepatitis B virus-related HCC patients in Hong Kong and discuss the recent progress in several areas of liver transplantation.
文摘The composite tumors of the liver are very rare,including the coexistence of HCC(hepatocellular carcinoma)with NEC(neuroendocrine carcinoma).The rare occurrence of these tumors necessitates more reported cases in order to fully understand their clinical characteristics,behaviors and treatments.Herein is described an incidental collision tumor of HCC-NEC,along with a review of the literature focusing on their clinicopathological findings and prognosis.The tumor presented here was found incidentally in the hepatectomy specimen of a 56-yearold man who had undergone liver transplantation for rapidly progressive liver failure because of alcoholic hepatitis and cirrhosis.Imaging and laboratory examinations did not demonstrate tumor-related findings.During macroscopic examination,two sharply defined and distinctive areas(1.7 cm and 0.6 cm dimension respectively)were detected among the cirrhotic nodules.The characteristic histopathological features and immunohistochemical findings allowed a diagnosis of HCCNEC to be made.There was no evidence of recurrence and metastasis after 10months following surgery.The present case and review revealed that these tumors are frequently found in older ages and males.Although serum markers are valuable in the discrimination of malignant tumors,their absence cannot completely rule out composite HCC-NEC.Diagnosis requires a comprehensive histopathological evaluation together with immunohistochemistry.The NEC component might influence the treatment strategy and eventually the outcome of the patient.In conclusion,the rare occurrence of HCC-NEC and the lack of diagnostic clinical signs and symptoms do not exclude their consideration in the differential diagnosis of liver tumors,especially in patients with the chronic liver disease.
