Objectives: To clone and express Tp0453 outer membrane protein of Treponema pallidum, and to evaluate its significance in the serodiagnosis of syphilis. Methods: The immuno-dominant epitope of Tp0453 gene was amplif...Objectives: To clone and express Tp0453 outer membrane protein of Treponema pallidum, and to evaluate its significance in the serodiagnosis of syphilis. Methods: The immuno-dominant epitope of Tp0453 gene was amplified from the complete genome of T.pallidum by polymerase chain reactions (PCR), subcloned into the expression vector Pqe32 to generate recombinant plasmid Pqe32/Tp0453, and was then expressed in E. coli M15. The fusion protein was purified with Ni-NTA affinity purification. Indirect ELISA was developed to detect human serum IgG antibody to T. pallidum. Results: The recombinant Tp0453 protein was successfully expressed and purified. The recombinant protein had a molecular weight of approximately 32KDa.Indirect ELISA to the recombinant protein was developed.Sixty control sera were tested by ELISA and yielded a sensitivity of 100% (30/30) and a specificity of 100% (30/30). While testing for T. pallidum in human sera, the sensitivity and specificity of ELISA were 96.8% and 100%, respectively, when compared with TPPA test results. The concordance of results between the ELISA test and the TPPA test was 98.2%. Conclusion: The recombinant Tp0453 outer membrane protein elicited a strong immunoreaction to anti-T.pallidum IgG antibody and has great potential use in ELISA for the serodiagnosis of syphilis.展开更多
Objective: To construct a recombinant plasmid containing the outer membrane protein 2 (Omp2) gene of Chlamydia trachomatis and express Omp2 in E.coli. Methods: The omp2 gene of C. trachomatis serovar D was cloned into...Objective: To construct a recombinant plasmid containing the outer membrane protein 2 (Omp2) gene of Chlamydia trachomatis and express Omp2 in E.coli. Methods: The omp2 gene of C. trachomatis serovar D was cloned into pQE30 vector following PCR amplification from genomic DNA. E. coli M15 transformants were induced to express the fusion protein by IPTG and the product was identified by SDS-PAGE and Western blot. Results: Confirmed by enzyme cleavage analysis and DNA sequencing, a correct recombinant plasmid pQE30/omp2 was constructed. The fusion protein from the transformants was approximately 60 kDa in size in SDS-PAGE analysis, which could specially react with anti-6 X His mouse monoclonal IgG antibodies. Conclusion: We successfully expressed Omp2 in E. coli M15, providing an efficient and simple system for assaying the immunological properties of Omp2.展开更多
In order to solve the dynamic reconstruction and local updating problem of three-dimensional geological solids, topology reasoning is used for three-dimensional geological modeling. This can advance the level of the c...In order to solve the dynamic reconstruction and local updating problem of three-dimensional geological solids, topology reasoning is used for three-dimensional geological modeling. This can advance the level of the corresponding section automation in implementing the 3D geological solid dynamical reconstruction by the construction of and reasoning on topology on the 3D curved surface. This method has been successfully used in the Nanjing city geological modeling and the Zijin gold mine modeling. The results prove that this method adapts to coplanar section and noncoplanar section data, and improves the efficiency of 3D geological modeling.展开更多
Chloroplast simple sequence repeat (cpSSR) markers in Citrus were developed and successfully used to analyze chloroplast genome inheritance of Citrus somatic hybrids. Twenty-two previously reported cpSSR primer pairs ...Chloroplast simple sequence repeat (cpSSR) markers in Citrus were developed and successfully used to analyze chloroplast genome inheritance of Citrus somatic hybrids. Twenty-two previously reported cpSSR primer pairs from pine (Pinus thunbergii Parl.), rice (Otyza sativa L.) and tobacco (Nicotiana tabacum L.) were tested in Citrus, nine of which could amplify intensive PCR products by agarose gel electrophoresis. Chloroplast genome inheritance of Citrus somatic hybrids from nine fusions was then analyzed, and five of the nine pre-screened primer pairs showed polymorphisms by polyacrylamide gel electrophoresis. The results revealed the random inheritance nature of chloroplast genome in all analyzed Citrus somatic hybrids, which was in agreement with previous reports based on RFLP or CAPS analyses. It was also shown that cpSSR is a more efficient tool in chloroplast genome analyses of somatic hybrids in higher plants, compared with the conventional RFLP or CAPS analyses.展开更多
Coactivators and corepressors regulate transcriptionby controlling interactions between sequence-specific transcription factors, the basal transcriptional machinery andthe chromatin environment. This review consider t...Coactivators and corepressors regulate transcriptionby controlling interactions between sequence-specific transcription factors, the basal transcriptional machinery andthe chromatin environment. This review consider the access of nuclear and steroid receptors to chromatin, theiruse of corepressors and coactivators to modify chromatinstructure and the implications for transcriptional control.The assembly of specific nucleoprotein architectures andtargeted histone modification emerge as central controlling elements for gene expression.展开更多
In order to study the gas explosion suppression performance based on ferrocene, the self-constructed experimental facility was used to accomplish the experiment of gas explosion suppression. By means of thermogravimet...In order to study the gas explosion suppression performance based on ferrocene, the self-constructed experimental facility was used to accomplish the experiment of gas explosion suppression. By means of thermogravimetric analysis, the thermal characteristics of ferrocene have been gotten and the gas explosion suppression mechanism of ferrocene has been analyzed. The results show that ferrocene had good effects on gas explosion suppression, and the explosion pressure and flame propagation speed declined obviously. When ferrocene concentration is 0.08 g/L and methane volume concentration is 9.5%, the maximum explosion overpressure and maximum flame propagation speed of methane-air respectively decreased by about 59.5% and 19.6%, respectively. TG and DSC curves showed that the mass loss of ferrocene consists of two processes, which are sublimation and lattice fracture. The temperature of mass loss ranged from 128 ℃ to 230 ℃. The results showed profoundly theoretical significance to gas explosion suppression by ferrocene in coal mines.展开更多
AIM: To insert the constructed TGF-β1 epitope gene into the el loop of C-terminus of truncated hepatitis B core antigen to increase TGF-β1 antigenicity in its prokaryotic expression system and to identify immunity ...AIM: To insert the constructed TGF-β1 epitope gene into the el loop of C-terminus of truncated hepatitis B core antigen to increase TGF-β1 antigenicity in its prokaryotic expression system and to identify immunity of the expressed recombinant protein in order to exploit the possibility for obtaining anti- TGF-β1 vaccine. METHODS: The TGF-β1 encoding epitope gene (the mature TGF-β1 from 78-109 amino acid residues, TGF-β1^32) was amplified by polymerase chain reaction from the recombinant pGEM-7z/ TGF-β1 ^32 vector. The HBcAg gene fragments (encoding HBcAg from 1-71 and 89-144 amino acid residues) were amplified from PYTAI- HBcAg vector. The recombinant vector pGEMEX-1 was used to insert HBcAg1-71, TGF-β1^32 and HBcAg89-144 into restrictive endonuclease enzyme and ligated with T4 Ugase. The fusion gene fragments HBc.Ag1-71-TGF-β1^32 HBcAg89-144 were recloned to pET28a(+) and the DNA sequence was confirmed by the dideoxy chain termination method. The recombinant vector pET28a (+)/ CTC was transformed and expressed in E. coli BL21 (DE3) under induction of IPTG. After purification with Ni^+2 NTA agarose resins, the antigenicity of purified protein was detected by ELISA and Western blot and visualized under electron microscope. RESULTS: Enzyme digestion analysis and sequencing showed that TGF-β1 epitope gene was inserted into the el loop of C-terminus of truncated hepatitis B core antigen. SDS-PAGE analysis showed that relative molecular mass (Mr) of the expressed product by pET28a (+)/CTC was Mr 24 600.The output of the target recombinant protein was approximately 34.8% of the total bacterial protein,mainly presented in the form of inclusion body. Western blotting and ELISA demonstrated that the fusion protein could combine with anti-TGF-β1 polyclonal IgG but not with anti-HBcAg. The purity of protein was about 90 % and the protein was in the form of self-assembling particles visualized under electron microscope. This fusion protein had good anti-TGF-β1 antigenicity and could be used as anti-TGF-β1 vaccine. CONCLUSION: A recombinant prokaryotic expression system with high expression efficiency of the target TGF-β1 epitope gene was successfully established. The fusion protein is in the form of self-assembling particles and HBcAg can increase the antigenicity of TGF-β1. The expressed TGF-β1 epitope gene shows good immunogenicity and antigenicity.展开更多
The bioavailability of 22 heavy metals was investigated at 19 sampling sites in Tieguanyin tea garden in Anxi County,Fujian Province,southeastern China.Heavy metal concentrations were determined by inductively coupled...The bioavailability of 22 heavy metals was investigated at 19 sampling sites in Tieguanyin tea garden in Anxi County,Fujian Province,southeastern China.Heavy metal concentrations were determined by inductively coupled plasma-mass spectrometry(ICP-MS)and evaluated by geo-accumulation index(I_(geo)).Dilute nitric acid extraction was used to evaluate biological activity.Cu,Pb,and Cd were highly bioavailable and most easily absorbed by tea trees.Heavy metal bioavailability in the surface soil was as the ratio of the effective state to the total amount.Cd had the highest I_(geo)values,and the respective samples and sites were classified as moderately/strongly contaminated.Cd element is considered the main factor of heavy metal pollution in the tea garden in Anxi.The other heavy metals studied were present in lower concentrations;thus,the samples were classified as uncontaminated or slightly contaminated.展开更多
Objective.To construct recombinant BCG again st leptospirosis.Methods.We amplified the entire open readin g frame of the OmpL1gene from the genome of the leptospire serovar Lai strain 017.Two recombin ant plasmids pBQ...Objective.To construct recombinant BCG again st leptospirosis.Methods.We amplified the entire open readin g frame of the OmpL1gene from the genome of the leptospire serovar Lai strain 017.Two recombin ant plasmids pBQ1and pBQ2were constructed by oriented ligation based on the E.coli-BCG shuttle plasmids pMV261and pMV361respectively.The recombinant plasmids were transformed into BCG by electroporation.The rBCGs bearing pBQ1and pBQ2were induced by high temperature of 45℃.Results.The expressed product,a 35kD prote in was detected by SDS-PAGE.The resu lt indicates that pBQ1and pBQ2can express OmpL1in rBCG.Conclusion.The technical methods in this study may help detect the immunogenicity a nd immunoprotection of OmpL1and develop more safe,highl y effective rBCG bearing leptospira l antigen with long-lasting protection.展开更多
Nitrogen balance method and nitrogen-free diet were used in this study to determine nitrogen maintenance requirement (NM) and nitrogen maintenance requirement per unit metabolism body weight (NM’) of black porgy Acan...Nitrogen balance method and nitrogen-free diet were used in this study to determine nitrogen maintenance requirement (NM) and nitrogen maintenance requirement per unit metabolism body weight (NM’) of black porgy Acanthopagrus schlegeli. Fish with body weight (BW) of 50, 80, 120, 160 and 200 g were fed by the diets containing three graded levels of crude protein (380, 420 and 460 g/kg). The results from nitrogen balance experiment showed that the amount of nitrogen deposition varied from 0.15 to 0.31 mg/g BW per day, accounting for 12.2% to 21.1% of nitrogen intake. The amount of fecal nitrogen excretion varied from 0.21 to 0.32 mg/g BW per day, accounting for 16.3% to 21.6% of nitrogen intake. The endogenous nitrogen excretion, a main part of nitrogen consumption varied from 0.79 to 0.97 mg/g BW per day, accounting for 63.3 % to 68.0% of nitrogen intake. Positive correlation was found between NM and body weight, while a negative correlation was found between NM of unit body weight and the growth duration. No significant differences (p>0.05) were found in NM’ among different growth stages. The average of NM’ was 0.485 7mg/g per day. The results from nitrogen-free diet experiment showed that a negative correlation between NM and feed intake of nitrogen-free diet. NM increased with the decrease of feed intake of fish. The average of NM was 0.482 9 mg/g BW per day that was close to 0.483 8 mg/g BW obtained from fish with 120 g BW in nitrogen balance experiment. The nitrogen balance method is recommended to be a better method for determining NM in consideration of fish stress and result stability. This study also provides a calculated result of the protein content in diets, which is necessary for maintaining fish body protein at different growth stages. The calculation was based on the amount of nitrogen required for maintaining body protein per kg BW.展开更多
Osteoporosis is a disease characterized by a low bone mineral density and structural deterioration of bone tissue. Leptin is considered to play a role in the maintenance of energy balance and body weight. Weight and b...Osteoporosis is a disease characterized by a low bone mineral density and structural deterioration of bone tissue. Leptin is considered to play a role in the maintenance of energy balance and body weight. Weight and body mass index are associated with low bone mineral density with high serum leptin concentration in older women. The study is designed to elucidate the impact of age and BMI (Body Mass Index) on osteoporotic patients (Iraqi postmenopausal women) and the functional role of leptin in those patients. A total of 72 patients divided into three groups according to BMI and two groups according to age: BMD (bone mineral density), T-score and serum leptin concentration increased as BMI increased, while with increased age, BMD and T-score deceased and serum leptin concentration increased. There is a significant difference of BMD and T-score in BMI (25-30) group and BMI (〉 30) group from that in BMI (〈 25) group. In conclusions: Both age and BMI have an impact on osteoporosis although age shows more impact on the severity of the disease than does BMI. Studying the direct impact of leptin on BMD may open the way in using new methods in treating and preventing the osteoporosis in patients with risk factors.展开更多
Objective:To construct and identify the recombinant plasmids PPARγ-pSUPER-EGFP for RNA interference. Methods: The pSUPER-EGFP vectors were used to transcribe functional short interfering RNA (siRNA). Four pairs o...Objective:To construct and identify the recombinant plasmids PPARγ-pSUPER-EGFP for RNA interference. Methods: The pSUPER-EGFP vectors were used to transcribe functional short interfering RNA (siRNA). Four pairs of 64 nt PPARγ siRNA encoding sequences were inserted into the downstream of the H1 promoter. The recombinant plasmids were confirmed by double digestion with the enzymes and sequencing. Western blotting was used to examine the silencing effect of PPARγ gene in RAW264.7 cells. Following procedures were used to optimize the experiments: the oligonucleotides were incubated 5 min at 95 C and cooled automatically in boiled water bath to anneal, and then phosphorylated oligonucleotides, pSUPER-EGFP plasmids was digested with Bgl Ⅱ and Hind Ⅲ , and the product was ligated into digested pSUPER-EGFP plasmids, and transforming the ligation products followed by screening and identifying positive clones. Results :Four kinds of positive clones producing 285 bp fragments were selected. Sequencing further proved their correctness. Four recombinant plasmids containing corresponding PPARγ gene-specific target sequences induced the silencing of its target gene more or less. Conclusion: The optimizing method in constructing these recombinant plasmids serves other plasmid-based RNA interference research. The final plasmids PPARγ-pSUPER-EGFP established the basis for research on the function of PPARγ gene.展开更多
The study was conducted to investigate the effects of feeding high-fiber diet (HFD) on apparent total tract digestibility (ATTD) and absorption of minerals in growing pigs. Sixteen barrows averaging 16.39 kg were ...The study was conducted to investigate the effects of feeding high-fiber diet (HFD) on apparent total tract digestibility (ATTD) and absorption of minerals in growing pigs. Sixteen barrows averaging 16.39 kg were randomly assigned to one of four diets after metabolic crate assignment with individual pig serving as experimental unit. Diets include: a corn-soybean meal based low-fiber diet (LFD), as the control (CON) and 3 HFD (D1, D2 and D3), each containing 5% sugar beet pulps and a 1:2, 1:1 and 2:1 oats to barley ratios, respectively, replacing 47% of the corn in the diet. Diets were formulated to meet nutrient requirements, however, the fiber content of the LFD was substantially lower than the average of the HFD (8.38% vs. 22.40%). Feed allowance was limited to 10% of average body weight and fed twice/d. The study period was divided into 10 d of adjustment and 5 d of feces collection. Data collected were analyzed using SAS, GLIMMIX procedure where animals were considered random effects, and minerals were fixed. Results of the study show that digestibility of Ca in pigs fed HFD was lower (P 〈 0.05) than in pigs fed LFD. On the other hand, the apparent digestibility of P, K, Na, S and Zn in pigs fed D2 and D3 were higher (P 〈 0.05) than in pigs fed CON diet. It was also observed that digestibility of Ca, P, K, Na, S and Zn in pigs fed D1 were lower (P 〈 0.05) than in CON, D2 or D3 fed pigs. Therefore, it was concluded that while feeding HFD reduced availability of Ca, the availability of P, K, Na and S to pigs improved as the oat to barley ratio in the diet increased.展开更多
AIM:To examine the effects of long-term proton pump inhibitor (PPI) therapy on body weight (BW) and body mass index (BMI) in patients with gastroesophageal reflux disease (GERD).METHODS: The subjects were 52 patients ...AIM:To examine the effects of long-term proton pump inhibitor (PPI) therapy on body weight (BW) and body mass index (BMI) in patients with gastroesophageal reflux disease (GERD).METHODS: The subjects were 52 patients with GERD and 58 sex-and age-matched healthy controls. GERD patients were treated with PPI for a mean of 2.2 years (range, 0.8-5.7 years), and also advised on lifestyle modifications (e.g. selective diet, weight management). BW, BMI and other parameters were measured at baseline and end of study.RESULTS: Twenty-four GERD patients were treated daily with 10 mg omeprazole, 12 with 20 mg omeprazole, 8 with 10 mg rabeprazole, 5 with 15 mg lansoprazole, and 3 patients with 30 mg lansoprazole. At baseline, there were no differences in BW and BMI between reflux patients and controls. Patients with GERD showed increases in BW (baseline: 56.4±10.4 kg, end: 58.6±10.8 kg, mean±SD, P<0.0001) and BMI (baseline: 23.1±3.1 kg/m2, end: 24.0±3.1 kg/m2, P<0.001), but no such changes were noted in the control group. Mean BW increased by 3.5 kg (6.2% of baseline) in 37 (71%) reflux patients but decreased in only 6 (12%) patients during treatment.CONCLUSION: Long-term PPI treatment was associated with BW gain in patients with GERD. Reflux patients receiving PPI should be encouraged to manage BW through lifestyle modifi cations.展开更多
This study was aimed to explore the use of creatinine as indicator to predict carcass and its protein weight in beef cattle. Eight Ongole crossbred cattle with initial body weight ranged at 133.5-228 kg and age of 6-1...This study was aimed to explore the use of creatinine as indicator to predict carcass and its protein weight in beef cattle. Eight Ongole crossbred cattle with initial body weight ranged at 133.5-228 kg and age of 6-18 months were used in this study. The cattle were fed Napier grass ad libitum and concentrate feeding for three months prior to be slaughtered. Concentrate feeding was consisted of rice bran and soybean meal which was provided to fulfill dry matter requirement at 2.1% of body weight (BW). The availability of creatinine for prediction indicator was done by evaluate the correlation between the amount of daily urinary creatinine and the carcass and its protein weight. Carcass and its protein weight were measured by slaughtering the cattle, and chemically analyzed for determining protein content of carcass. The results showed that creatinine excreted in urine have a strong correlation with the cattle body weight (r = 0.88), carcass weight (r = 0.67), body protein (r = 0.70) and carcass protein (r = 0.72). The conclusion of this study is creatinine excreted in urine have a strong relationship with the carcass and its protein, and therefore could be used to predict the carcass and its protein weight of beef cattle.展开更多
An 8-week growth trial was conducted to determine dietary arginine requirement for juvenile Pacific white shrimp Litopenaeus vannamei (Boone) with an initial average body weight of 0.47 g reared in low-salinity wat...An 8-week growth trial was conducted to determine dietary arginine requirement for juvenile Pacific white shrimp Litopenaeus vannamei (Boone) with an initial average body weight of 0.47 g reared in low-salinity water (0.50-1.50 g L-1). Six isonitrogenous and isoenergetic semipurified diets (crude protein 360 g/kg and gross energy 19.70 kJ/g) were formulated with fish meal and wheat gluten as the intact protein source.展开更多
基金Financially supported by Key grant from the Education Committee of Hunan Province (No. 02A046)
文摘Objectives: To clone and express Tp0453 outer membrane protein of Treponema pallidum, and to evaluate its significance in the serodiagnosis of syphilis. Methods: The immuno-dominant epitope of Tp0453 gene was amplified from the complete genome of T.pallidum by polymerase chain reactions (PCR), subcloned into the expression vector Pqe32 to generate recombinant plasmid Pqe32/Tp0453, and was then expressed in E. coli M15. The fusion protein was purified with Ni-NTA affinity purification. Indirect ELISA was developed to detect human serum IgG antibody to T. pallidum. Results: The recombinant Tp0453 protein was successfully expressed and purified. The recombinant protein had a molecular weight of approximately 32KDa.Indirect ELISA to the recombinant protein was developed.Sixty control sera were tested by ELISA and yielded a sensitivity of 100% (30/30) and a specificity of 100% (30/30). While testing for T. pallidum in human sera, the sensitivity and specificity of ELISA were 96.8% and 100%, respectively, when compared with TPPA test results. The concordance of results between the ELISA test and the TPPA test was 98.2%. Conclusion: The recombinant Tp0453 outer membrane protein elicited a strong immunoreaction to anti-T.pallidum IgG antibody and has great potential use in ELISA for the serodiagnosis of syphilis.
基金This work was supported in part by grants from the Department of Science and Technology of Hunan Province (No. 01SSY2008-6) the Department of Health of Hunan Province (No. B2003-078).
文摘Objective: To construct a recombinant plasmid containing the outer membrane protein 2 (Omp2) gene of Chlamydia trachomatis and express Omp2 in E.coli. Methods: The omp2 gene of C. trachomatis serovar D was cloned into pQE30 vector following PCR amplification from genomic DNA. E. coli M15 transformants were induced to express the fusion protein by IPTG and the product was identified by SDS-PAGE and Western blot. Results: Confirmed by enzyme cleavage analysis and DNA sequencing, a correct recombinant plasmid pQE30/omp2 was constructed. The fusion protein from the transformants was approximately 60 kDa in size in SDS-PAGE analysis, which could specially react with anti-6 X His mouse monoclonal IgG antibodies. Conclusion: We successfully expressed Omp2 in E. coli M15, providing an efficient and simple system for assaying the immunological properties of Omp2.
基金the Research Foundation for Outstanding Young Teachers, China University of Geosciences.
文摘In order to solve the dynamic reconstruction and local updating problem of three-dimensional geological solids, topology reasoning is used for three-dimensional geological modeling. This can advance the level of the corresponding section automation in implementing the 3D geological solid dynamical reconstruction by the construction of and reasoning on topology on the 3D curved surface. This method has been successfully used in the Nanjing city geological modeling and the Zijin gold mine modeling. The results prove that this method adapts to coplanar section and noncoplanar section data, and improves the efficiency of 3D geological modeling.
文摘Chloroplast simple sequence repeat (cpSSR) markers in Citrus were developed and successfully used to analyze chloroplast genome inheritance of Citrus somatic hybrids. Twenty-two previously reported cpSSR primer pairs from pine (Pinus thunbergii Parl.), rice (Otyza sativa L.) and tobacco (Nicotiana tabacum L.) were tested in Citrus, nine of which could amplify intensive PCR products by agarose gel electrophoresis. Chloroplast genome inheritance of Citrus somatic hybrids from nine fusions was then analyzed, and five of the nine pre-screened primer pairs showed polymorphisms by polyacrylamide gel electrophoresis. The results revealed the random inheritance nature of chloroplast genome in all analyzed Citrus somatic hybrids, which was in agreement with previous reports based on RFLP or CAPS analyses. It was also shown that cpSSR is a more efficient tool in chloroplast genome analyses of somatic hybrids in higher plants, compared with the conventional RFLP or CAPS analyses.
文摘Coactivators and corepressors regulate transcriptionby controlling interactions between sequence-specific transcription factors, the basal transcriptional machinery andthe chromatin environment. This review consider the access of nuclear and steroid receptors to chromatin, theiruse of corepressors and coactivators to modify chromatinstructure and the implications for transcriptional control.The assembly of specific nucleoprotein architectures andtargeted histone modification emerge as central controlling elements for gene expression.
基金Supported by the National Natural Science Foundation of China (50974055, 50476033) the Doctor Foundation Project from the Henan Polytechnic University (B2011 - 101)
文摘In order to study the gas explosion suppression performance based on ferrocene, the self-constructed experimental facility was used to accomplish the experiment of gas explosion suppression. By means of thermogravimetric analysis, the thermal characteristics of ferrocene have been gotten and the gas explosion suppression mechanism of ferrocene has been analyzed. The results show that ferrocene had good effects on gas explosion suppression, and the explosion pressure and flame propagation speed declined obviously. When ferrocene concentration is 0.08 g/L and methane volume concentration is 9.5%, the maximum explosion overpressure and maximum flame propagation speed of methane-air respectively decreased by about 59.5% and 19.6%, respectively. TG and DSC curves showed that the mass loss of ferrocene consists of two processes, which are sublimation and lattice fracture. The temperature of mass loss ranged from 128 ℃ to 230 ℃. The results showed profoundly theoretical significance to gas explosion suppression by ferrocene in coal mines.
文摘AIM: To insert the constructed TGF-β1 epitope gene into the el loop of C-terminus of truncated hepatitis B core antigen to increase TGF-β1 antigenicity in its prokaryotic expression system and to identify immunity of the expressed recombinant protein in order to exploit the possibility for obtaining anti- TGF-β1 vaccine. METHODS: The TGF-β1 encoding epitope gene (the mature TGF-β1 from 78-109 amino acid residues, TGF-β1^32) was amplified by polymerase chain reaction from the recombinant pGEM-7z/ TGF-β1 ^32 vector. The HBcAg gene fragments (encoding HBcAg from 1-71 and 89-144 amino acid residues) were amplified from PYTAI- HBcAg vector. The recombinant vector pGEMEX-1 was used to insert HBcAg1-71, TGF-β1^32 and HBcAg89-144 into restrictive endonuclease enzyme and ligated with T4 Ugase. The fusion gene fragments HBc.Ag1-71-TGF-β1^32 HBcAg89-144 were recloned to pET28a(+) and the DNA sequence was confirmed by the dideoxy chain termination method. The recombinant vector pET28a (+)/ CTC was transformed and expressed in E. coli BL21 (DE3) under induction of IPTG. After purification with Ni^+2 NTA agarose resins, the antigenicity of purified protein was detected by ELISA and Western blot and visualized under electron microscope. RESULTS: Enzyme digestion analysis and sequencing showed that TGF-β1 epitope gene was inserted into the el loop of C-terminus of truncated hepatitis B core antigen. SDS-PAGE analysis showed that relative molecular mass (Mr) of the expressed product by pET28a (+)/CTC was Mr 24 600.The output of the target recombinant protein was approximately 34.8% of the total bacterial protein,mainly presented in the form of inclusion body. Western blotting and ELISA demonstrated that the fusion protein could combine with anti-TGF-β1 polyclonal IgG but not with anti-HBcAg. The purity of protein was about 90 % and the protein was in the form of self-assembling particles visualized under electron microscope. This fusion protein had good anti-TGF-β1 antigenicity and could be used as anti-TGF-β1 vaccine. CONCLUSION: A recombinant prokaryotic expression system with high expression efficiency of the target TGF-β1 epitope gene was successfully established. The fusion protein is in the form of self-assembling particles and HBcAg can increase the antigenicity of TGF-β1. The expressed TGF-β1 epitope gene shows good immunogenicity and antigenicity.
基金supported by the National Science Foundation of China(21177043,21377042)the National Science Foundation of Fujian Province(2015J01147)+1 种基金Fujian Provincial Key Laboratory of Ecology-Toxicological Effects and Control for Emerging Contaminants(PY16006)the Research Program of Science and Technology of Quanzhou City Government(2012Z86,2014Z130)
文摘The bioavailability of 22 heavy metals was investigated at 19 sampling sites in Tieguanyin tea garden in Anxi County,Fujian Province,southeastern China.Heavy metal concentrations were determined by inductively coupled plasma-mass spectrometry(ICP-MS)and evaluated by geo-accumulation index(I_(geo)).Dilute nitric acid extraction was used to evaluate biological activity.Cu,Pb,and Cd were highly bioavailable and most easily absorbed by tea trees.Heavy metal bioavailability in the surface soil was as the ratio of the effective state to the total amount.Cd had the highest I_(geo)values,and the respective samples and sites were classified as moderately/strongly contaminated.Cd element is considered the main factor of heavy metal pollution in the tea garden in Anxi.The other heavy metals studied were present in lower concentrations;thus,the samples were classified as uncontaminated or slightly contaminated.
文摘Objective.To construct recombinant BCG again st leptospirosis.Methods.We amplified the entire open readin g frame of the OmpL1gene from the genome of the leptospire serovar Lai strain 017.Two recombin ant plasmids pBQ1and pBQ2were constructed by oriented ligation based on the E.coli-BCG shuttle plasmids pMV261and pMV361respectively.The recombinant plasmids were transformed into BCG by electroporation.The rBCGs bearing pBQ1and pBQ2were induced by high temperature of 45℃.Results.The expressed product,a 35kD prote in was detected by SDS-PAGE.The resu lt indicates that pBQ1and pBQ2can express OmpL1in rBCG.Conclusion.The technical methods in this study may help detect the immunogenicity a nd immunoprotection of OmpL1and develop more safe,highl y effective rBCG bearing leptospira l antigen with long-lasting protection.
基金Supported by Scientific Research Project Grant (No.2004C100059) from the city government of Ningbo, China.
文摘Nitrogen balance method and nitrogen-free diet were used in this study to determine nitrogen maintenance requirement (NM) and nitrogen maintenance requirement per unit metabolism body weight (NM’) of black porgy Acanthopagrus schlegeli. Fish with body weight (BW) of 50, 80, 120, 160 and 200 g were fed by the diets containing three graded levels of crude protein (380, 420 and 460 g/kg). The results from nitrogen balance experiment showed that the amount of nitrogen deposition varied from 0.15 to 0.31 mg/g BW per day, accounting for 12.2% to 21.1% of nitrogen intake. The amount of fecal nitrogen excretion varied from 0.21 to 0.32 mg/g BW per day, accounting for 16.3% to 21.6% of nitrogen intake. The endogenous nitrogen excretion, a main part of nitrogen consumption varied from 0.79 to 0.97 mg/g BW per day, accounting for 63.3 % to 68.0% of nitrogen intake. Positive correlation was found between NM and body weight, while a negative correlation was found between NM of unit body weight and the growth duration. No significant differences (p>0.05) were found in NM’ among different growth stages. The average of NM’ was 0.485 7mg/g per day. The results from nitrogen-free diet experiment showed that a negative correlation between NM and feed intake of nitrogen-free diet. NM increased with the decrease of feed intake of fish. The average of NM was 0.482 9 mg/g BW per day that was close to 0.483 8 mg/g BW obtained from fish with 120 g BW in nitrogen balance experiment. The nitrogen balance method is recommended to be a better method for determining NM in consideration of fish stress and result stability. This study also provides a calculated result of the protein content in diets, which is necessary for maintaining fish body protein at different growth stages. The calculation was based on the amount of nitrogen required for maintaining body protein per kg BW.
文摘Osteoporosis is a disease characterized by a low bone mineral density and structural deterioration of bone tissue. Leptin is considered to play a role in the maintenance of energy balance and body weight. Weight and body mass index are associated with low bone mineral density with high serum leptin concentration in older women. The study is designed to elucidate the impact of age and BMI (Body Mass Index) on osteoporotic patients (Iraqi postmenopausal women) and the functional role of leptin in those patients. A total of 72 patients divided into three groups according to BMI and two groups according to age: BMD (bone mineral density), T-score and serum leptin concentration increased as BMI increased, while with increased age, BMD and T-score deceased and serum leptin concentration increased. There is a significant difference of BMD and T-score in BMI (25-30) group and BMI (〉 30) group from that in BMI (〈 25) group. In conclusions: Both age and BMI have an impact on osteoporosis although age shows more impact on the severity of the disease than does BMI. Studying the direct impact of leptin on BMD may open the way in using new methods in treating and preventing the osteoporosis in patients with risk factors.
基金Supported by Open Fund of State Key Laboratory of Trauma, Burns and Combined Injury of Third Military Medical University and the National Funds for Outstanding Youth Scientists (30325040)
文摘Objective:To construct and identify the recombinant plasmids PPARγ-pSUPER-EGFP for RNA interference. Methods: The pSUPER-EGFP vectors were used to transcribe functional short interfering RNA (siRNA). Four pairs of 64 nt PPARγ siRNA encoding sequences were inserted into the downstream of the H1 promoter. The recombinant plasmids were confirmed by double digestion with the enzymes and sequencing. Western blotting was used to examine the silencing effect of PPARγ gene in RAW264.7 cells. Following procedures were used to optimize the experiments: the oligonucleotides were incubated 5 min at 95 C and cooled automatically in boiled water bath to anneal, and then phosphorylated oligonucleotides, pSUPER-EGFP plasmids was digested with Bgl Ⅱ and Hind Ⅲ , and the product was ligated into digested pSUPER-EGFP plasmids, and transforming the ligation products followed by screening and identifying positive clones. Results :Four kinds of positive clones producing 285 bp fragments were selected. Sequencing further proved their correctness. Four recombinant plasmids containing corresponding PPARγ gene-specific target sequences induced the silencing of its target gene more or less. Conclusion: The optimizing method in constructing these recombinant plasmids serves other plasmid-based RNA interference research. The final plasmids PPARγ-pSUPER-EGFP established the basis for research on the function of PPARγ gene.
文摘The study was conducted to investigate the effects of feeding high-fiber diet (HFD) on apparent total tract digestibility (ATTD) and absorption of minerals in growing pigs. Sixteen barrows averaging 16.39 kg were randomly assigned to one of four diets after metabolic crate assignment with individual pig serving as experimental unit. Diets include: a corn-soybean meal based low-fiber diet (LFD), as the control (CON) and 3 HFD (D1, D2 and D3), each containing 5% sugar beet pulps and a 1:2, 1:1 and 2:1 oats to barley ratios, respectively, replacing 47% of the corn in the diet. Diets were formulated to meet nutrient requirements, however, the fiber content of the LFD was substantially lower than the average of the HFD (8.38% vs. 22.40%). Feed allowance was limited to 10% of average body weight and fed twice/d. The study period was divided into 10 d of adjustment and 5 d of feces collection. Data collected were analyzed using SAS, GLIMMIX procedure where animals were considered random effects, and minerals were fixed. Results of the study show that digestibility of Ca in pigs fed HFD was lower (P 〈 0.05) than in pigs fed LFD. On the other hand, the apparent digestibility of P, K, Na, S and Zn in pigs fed D2 and D3 were higher (P 〈 0.05) than in pigs fed CON diet. It was also observed that digestibility of Ca, P, K, Na, S and Zn in pigs fed D1 were lower (P 〈 0.05) than in CON, D2 or D3 fed pigs. Therefore, it was concluded that while feeding HFD reduced availability of Ca, the availability of P, K, Na and S to pigs improved as the oat to barley ratio in the diet increased.
文摘AIM:To examine the effects of long-term proton pump inhibitor (PPI) therapy on body weight (BW) and body mass index (BMI) in patients with gastroesophageal reflux disease (GERD).METHODS: The subjects were 52 patients with GERD and 58 sex-and age-matched healthy controls. GERD patients were treated with PPI for a mean of 2.2 years (range, 0.8-5.7 years), and also advised on lifestyle modifications (e.g. selective diet, weight management). BW, BMI and other parameters were measured at baseline and end of study.RESULTS: Twenty-four GERD patients were treated daily with 10 mg omeprazole, 12 with 20 mg omeprazole, 8 with 10 mg rabeprazole, 5 with 15 mg lansoprazole, and 3 patients with 30 mg lansoprazole. At baseline, there were no differences in BW and BMI between reflux patients and controls. Patients with GERD showed increases in BW (baseline: 56.4±10.4 kg, end: 58.6±10.8 kg, mean±SD, P<0.0001) and BMI (baseline: 23.1±3.1 kg/m2, end: 24.0±3.1 kg/m2, P<0.001), but no such changes were noted in the control group. Mean BW increased by 3.5 kg (6.2% of baseline) in 37 (71%) reflux patients but decreased in only 6 (12%) patients during treatment.CONCLUSION: Long-term PPI treatment was associated with BW gain in patients with GERD. Reflux patients receiving PPI should be encouraged to manage BW through lifestyle modifi cations.
文摘This study was aimed to explore the use of creatinine as indicator to predict carcass and its protein weight in beef cattle. Eight Ongole crossbred cattle with initial body weight ranged at 133.5-228 kg and age of 6-18 months were used in this study. The cattle were fed Napier grass ad libitum and concentrate feeding for three months prior to be slaughtered. Concentrate feeding was consisted of rice bran and soybean meal which was provided to fulfill dry matter requirement at 2.1% of body weight (BW). The availability of creatinine for prediction indicator was done by evaluate the correlation between the amount of daily urinary creatinine and the carcass and its protein weight. Carcass and its protein weight were measured by slaughtering the cattle, and chemically analyzed for determining protein content of carcass. The results showed that creatinine excreted in urine have a strong correlation with the cattle body weight (r = 0.88), carcass weight (r = 0.67), body protein (r = 0.70) and carcass protein (r = 0.72). The conclusion of this study is creatinine excreted in urine have a strong relationship with the carcass and its protein, and therefore could be used to predict the carcass and its protein weight of beef cattle.
文摘An 8-week growth trial was conducted to determine dietary arginine requirement for juvenile Pacific white shrimp Litopenaeus vannamei (Boone) with an initial average body weight of 0.47 g reared in low-salinity water (0.50-1.50 g L-1). Six isonitrogenous and isoenergetic semipurified diets (crude protein 360 g/kg and gross energy 19.70 kJ/g) were formulated with fish meal and wheat gluten as the intact protein source.