Background: Blood cultures (BCs) are obtained to identify etiologic organisms, demonstrate antibiotic efficacy, determine duration of treatment, and/or suggest further interventions. Published guidelines do not clearl...Background: Blood cultures (BCs) are obtained to identify etiologic organisms, demonstrate antibiotic efficacy, determine duration of treatment, and/or suggest further interventions. Published guidelines do not clearly state indications and timing for obtaining BCs. As a result, clinicians may obtain too many BCs, increasing cost and patient discomfort. Objective: To determine frequency of BCs performed at our hospital as part of a quality improvement project. Design: Retrospective review of all BCs submitted during a randomly selected month. Setting: A New York City 535-bed, university-affiliated community hospital. Measurements: Patient demographics and BC data were obtained from medical and laboratory records. Results: During the selected month, 2280 BCs were performed for 379 patients. Negative BCs were seen in 221 patients (58%) with one-half having multiple BCs performed within 48 hours of admission and prior to obtaining results of initial BCs. Repeat BCs frequently did not reveal further pathogens among patients with either negative or positive initial BCs. Conclusions: Two-thirds of BCs were obtained from less than one-half of patients without added clinical utility. Often, BCs were repeated prior to results of initial BCs or repeated in patients receiving antibiotics in spite of known low yield following antibiotic initiation. Clinical assessment and review of initial BCs prior to obtaining further BCs is necessary. Staff education regarding appropriate clinical setting for BCs and indications for repeat BCs is required to maximize utilization of resources, improve diagnostic yield, and limit patient discomfort.展开更多
Objective:To investigate the bacterial infections in repeat breeder dairy cows and to evaluate the treatment effects of hyperimmune serum against two main endometritis bacteria,Escherichia(E.)coli and Trueperella pyog...Objective:To investigate the bacterial infections in repeat breeder dairy cows and to evaluate the treatment effects of hyperimmune serum against two main endometritis bacteria,Escherichia(E.)coli and Trueperella pyogenes.Methods:A total of 29 Holstein multiparous cows with three or more unsuccessful artificial inseminations were carried out and examined to confirm the absence of reproductive tract abnormality and vaginal discharges.Uterine lavage was performed to collect uterine samples for bacterial and fungal cultures.In addition,polymerase chain reaction(PCR)was done to detect Trueperella pyogenes,E.coli,Fusobacterium necrophorum,and Prevotella melaninogenicus.The cytological study was done on cervical mucus.The hyperimmune serums produced against Trueperella pyogenes and E.coli were infused into the uterus of repeat breeder cows and two doses of prostaglandin F2αwere administrated intramuscularly within 14 days'interval.Results:There were 10 positive samples in the bacterial culture with 19 isolations and no growth of the main causative bacteria of endometritis.In the PCR method,no Trueperella pyogenes,Fusobacterium necrophorum,and Prevotella melaninogenicus were found.However,11 positive samples of E.coli were identified by PCR.Cladosporium was detected in one case of repeat breeder cows.The median(interquartile range)of neutrophils in vaginal discharge was 12(22.5).Eighteen from twenty-nine(62.1%)repeat breeder and eight from eleven(72%)cows with E.coli infections in PCR were made pregnant in the first artificial insemination after treatment by intrauterine infusion of hyperimmune serum and prostaglandin F2α.Conclusions:Intrauterine administration of hyperimmune serum could be an alternative to antibiotics for the treatment of repeat breeder cows.展开更多
An alkalophilc and thermophilic Bacillus sp. BHA that produced a thermostable alkaline protease was isolated from decaying protein substrates. The isolate was found to grow in pH range 7 - 11 with an optimum pH 9.0 an...An alkalophilc and thermophilic Bacillus sp. BHA that produced a thermostable alkaline protease was isolated from decaying protein substrates. The isolate was found to grow in pH range 7 - 11 with an optimum pH 9.0 and temperature up to 55℃. The activity of alkaline protease of Bacillus sp. BHA (68.98 APU/ml) was found higher than the standard strains of Bacillus amyloliquefaciens MTCC 610 (8.98 APU/ml) and Bacillus subtilis MTCC 8349 (12.14 APU/ml, used in this study, and was comparable (68.98 APU/ml, equivalent to 30.38 APU/mg) to the activity of the commercially produced standard protease procured from Novo Nordisk, Denmark (30.35 APU/mg). Hence, the proteolytic activity produced by this isolate was further investigated in batch and fed-batch process. Sucrose was the best carbon source for the production of protease activity by that isolate. Different organic nitrogen sources (casein, peptone and beef extract) at 1% (w/v) with varying levels of sucrose (1% - 4% w/v) initially repress enzyme synthesis. The duration and extent of repression decreased with increased concentration of sucrose. Maximum protease activity was found in basal medium with 4% (w/v) sucrose and 1% (w/v) yeast extract. Yeast-extract was thought to be an inducer of enzyme synthesis. Further, the basal medium was unique with respect to the enzyme production, as protease production was growth associated with the peak enzyme production being detected at the time of maximum growth. Interestingly, a rise in 34.2% (104.86 APU/ml) of protease activity was detected at incubation temperature of 50℃ and when culture filtrate was assayed at 60℃, signifying a high temperature stability of the produced protease by this isolate. Additional studies on the enzyme characterization were resulted in recognition of highly significant properties of the activity towards casein at pH 9.0 and stability at high temperature with retention of 96% the enzyme activity at 60℃. The parametric study under feed intervals had enabled improvement in the maximum protease activities attainable from batch cultures in excess of 21.78% and 26.32% via two feeding strategies. A small continual increase in enzyme activity (132.46 APU/ml during 24 h - 120 h) and enhancement in protease production in excess of 36.84% was observed by fed-batch process than the batch experiment.展开更多
The high growth-stimulating effect of plant extract has urged the plant biotechnologists to use natural supplements in the culture media instead of synthetic phytohormones. We advocated the effect of sprouted sorghum ...The high growth-stimulating effect of plant extract has urged the plant biotechnologists to use natural supplements in the culture media instead of synthetic phytohormones. We advocated the effect of sprouted sorghum extract(SSE) on emergence, in vitro acclimatization, and genetic fidelity in coleoptile derived callus of indica rice variety ADT36. The use of SSE with Murashige Skoog medium efficiently acclimatized the root and shoot apical systems. A higher mat and seminal roots(3.4 g biomass) with an efficient shoot primordium elongation were observed with an increase in the concentration of SSE. Seeds treated with SSE medium showed higher germination and earlier coleoptile maturation about 48 h compared to untreated seeds, and there was a higher expression of e EF-1α with an increase in coleoptile length. B5 medium was effective on inducing embryogenic and nodular callus from 3-day-old coleoptile with 3.0 mg/L 2,4-dichlorophenoxyacetic acid and further proliferated effectively with 0.8 mg/L kinetin with a fresh weight of 180 mg. Highly significant regeneration was observed with combination of 2.5 mg/L 6-benzylamino purine and 3.0 mg/L α-naphthaleneacetic acid. The metabolic and genetic profiles of in vitro and directly cultivated plants were the same, examined through Fourier-transform infrared spectroscopy, random amplified polymorphic DNA(RAPD), inter-simple sequence repeat(ISSR) and R-ISSR(combination of RAPD and ISSR) markers, respectively, and thus confirming the significant efficacy of the SSE incorporated medium. Disarmed T-DNA was transformed to coleoptile derived callus through Agrobacterium tumefaciens LBA4404 and confirmed by GUS assay. The T-DNA integration was confirmed by DNA blot analysis using DNA from transient GUS-expressed explants. Thus, SSE can be used as a natural and organic supplement for organogenesis and efficient acclimatizations of shoot and root apical meristems in regenerated plants.展开更多
Optimal control technique is crucial to improve the yield of microbial fermentation production.In this paper,we propose a nonlinear control system with state-dependent impulses,where the impulsive volume of feeding gl...Optimal control technique is crucial to improve the yield of microbial fermentation production.In this paper,we propose a nonlinear control system with state-dependent impulses,where the impulsive volume of feeding glycerol and the critical concentration of glycerol for occurring impulse are the control variables,to formulate 1,3-propanediol(1,3-PD)fed-batch production process.We also discuss a quantity of important properties for this control system.Then,we analyze the sensitivity of system state with respect to the kinetic parameters.We further propose a constrained optimal control model governed by the control system with state-dependent impulses.The existence of the optimal impulsive controls is established.For solving this problem,we utilize an exact penalty method to transform the problem into an optimization problem with only box constraints.Moreover,an improved differential evolution method is developed to seek the optimal impulsive strategy.Finally,numerical simulation results demonstrate that,by using the optimal impulsive strategies,final 1,3-PD concentration is considerably increased under the nominal parameter values and disturbances of kinetic parameters have significant effects on the optimal final 1,3-PD yield.展开更多
文摘Background: Blood cultures (BCs) are obtained to identify etiologic organisms, demonstrate antibiotic efficacy, determine duration of treatment, and/or suggest further interventions. Published guidelines do not clearly state indications and timing for obtaining BCs. As a result, clinicians may obtain too many BCs, increasing cost and patient discomfort. Objective: To determine frequency of BCs performed at our hospital as part of a quality improvement project. Design: Retrospective review of all BCs submitted during a randomly selected month. Setting: A New York City 535-bed, university-affiliated community hospital. Measurements: Patient demographics and BC data were obtained from medical and laboratory records. Results: During the selected month, 2280 BCs were performed for 379 patients. Negative BCs were seen in 221 patients (58%) with one-half having multiple BCs performed within 48 hours of admission and prior to obtaining results of initial BCs. Repeat BCs frequently did not reveal further pathogens among patients with either negative or positive initial BCs. Conclusions: Two-thirds of BCs were obtained from less than one-half of patients without added clinical utility. Often, BCs were repeated prior to results of initial BCs or repeated in patients receiving antibiotics in spite of known low yield following antibiotic initiation. Clinical assessment and review of initial BCs prior to obtaining further BCs is necessary. Staff education regarding appropriate clinical setting for BCs and indications for repeat BCs is required to maximize utilization of resources, improve diagnostic yield, and limit patient discomfort.
文摘Objective:To investigate the bacterial infections in repeat breeder dairy cows and to evaluate the treatment effects of hyperimmune serum against two main endometritis bacteria,Escherichia(E.)coli and Trueperella pyogenes.Methods:A total of 29 Holstein multiparous cows with three or more unsuccessful artificial inseminations were carried out and examined to confirm the absence of reproductive tract abnormality and vaginal discharges.Uterine lavage was performed to collect uterine samples for bacterial and fungal cultures.In addition,polymerase chain reaction(PCR)was done to detect Trueperella pyogenes,E.coli,Fusobacterium necrophorum,and Prevotella melaninogenicus.The cytological study was done on cervical mucus.The hyperimmune serums produced against Trueperella pyogenes and E.coli were infused into the uterus of repeat breeder cows and two doses of prostaglandin F2αwere administrated intramuscularly within 14 days'interval.Results:There were 10 positive samples in the bacterial culture with 19 isolations and no growth of the main causative bacteria of endometritis.In the PCR method,no Trueperella pyogenes,Fusobacterium necrophorum,and Prevotella melaninogenicus were found.However,11 positive samples of E.coli were identified by PCR.Cladosporium was detected in one case of repeat breeder cows.The median(interquartile range)of neutrophils in vaginal discharge was 12(22.5).Eighteen from twenty-nine(62.1%)repeat breeder and eight from eleven(72%)cows with E.coli infections in PCR were made pregnant in the first artificial insemination after treatment by intrauterine infusion of hyperimmune serum and prostaglandin F2α.Conclusions:Intrauterine administration of hyperimmune serum could be an alternative to antibiotics for the treatment of repeat breeder cows.
文摘An alkalophilc and thermophilic Bacillus sp. BHA that produced a thermostable alkaline protease was isolated from decaying protein substrates. The isolate was found to grow in pH range 7 - 11 with an optimum pH 9.0 and temperature up to 55℃. The activity of alkaline protease of Bacillus sp. BHA (68.98 APU/ml) was found higher than the standard strains of Bacillus amyloliquefaciens MTCC 610 (8.98 APU/ml) and Bacillus subtilis MTCC 8349 (12.14 APU/ml, used in this study, and was comparable (68.98 APU/ml, equivalent to 30.38 APU/mg) to the activity of the commercially produced standard protease procured from Novo Nordisk, Denmark (30.35 APU/mg). Hence, the proteolytic activity produced by this isolate was further investigated in batch and fed-batch process. Sucrose was the best carbon source for the production of protease activity by that isolate. Different organic nitrogen sources (casein, peptone and beef extract) at 1% (w/v) with varying levels of sucrose (1% - 4% w/v) initially repress enzyme synthesis. The duration and extent of repression decreased with increased concentration of sucrose. Maximum protease activity was found in basal medium with 4% (w/v) sucrose and 1% (w/v) yeast extract. Yeast-extract was thought to be an inducer of enzyme synthesis. Further, the basal medium was unique with respect to the enzyme production, as protease production was growth associated with the peak enzyme production being detected at the time of maximum growth. Interestingly, a rise in 34.2% (104.86 APU/ml) of protease activity was detected at incubation temperature of 50℃ and when culture filtrate was assayed at 60℃, signifying a high temperature stability of the produced protease by this isolate. Additional studies on the enzyme characterization were resulted in recognition of highly significant properties of the activity towards casein at pH 9.0 and stability at high temperature with retention of 96% the enzyme activity at 60℃. The parametric study under feed intervals had enabled improvement in the maximum protease activities attainable from batch cultures in excess of 21.78% and 26.32% via two feeding strategies. A small continual increase in enzyme activity (132.46 APU/ml during 24 h - 120 h) and enhancement in protease production in excess of 36.84% was observed by fed-batch process than the batch experiment.
文摘The high growth-stimulating effect of plant extract has urged the plant biotechnologists to use natural supplements in the culture media instead of synthetic phytohormones. We advocated the effect of sprouted sorghum extract(SSE) on emergence, in vitro acclimatization, and genetic fidelity in coleoptile derived callus of indica rice variety ADT36. The use of SSE with Murashige Skoog medium efficiently acclimatized the root and shoot apical systems. A higher mat and seminal roots(3.4 g biomass) with an efficient shoot primordium elongation were observed with an increase in the concentration of SSE. Seeds treated with SSE medium showed higher germination and earlier coleoptile maturation about 48 h compared to untreated seeds, and there was a higher expression of e EF-1α with an increase in coleoptile length. B5 medium was effective on inducing embryogenic and nodular callus from 3-day-old coleoptile with 3.0 mg/L 2,4-dichlorophenoxyacetic acid and further proliferated effectively with 0.8 mg/L kinetin with a fresh weight of 180 mg. Highly significant regeneration was observed with combination of 2.5 mg/L 6-benzylamino purine and 3.0 mg/L α-naphthaleneacetic acid. The metabolic and genetic profiles of in vitro and directly cultivated plants were the same, examined through Fourier-transform infrared spectroscopy, random amplified polymorphic DNA(RAPD), inter-simple sequence repeat(ISSR) and R-ISSR(combination of RAPD and ISSR) markers, respectively, and thus confirming the significant efficacy of the SSE incorporated medium. Disarmed T-DNA was transformed to coleoptile derived callus through Agrobacterium tumefaciens LBA4404 and confirmed by GUS assay. The T-DNA integration was confirmed by DNA blot analysis using DNA from transient GUS-expressed explants. Thus, SSE can be used as a natural and organic supplement for organogenesis and efficient acclimatizations of shoot and root apical meristems in regenerated plants.
基金supported by the National Natural Science Foundation of China(Grant No.12271307)the Natural Science Foundation of Shandong Province,China(Grant No.ZR2019MA031).
文摘Optimal control technique is crucial to improve the yield of microbial fermentation production.In this paper,we propose a nonlinear control system with state-dependent impulses,where the impulsive volume of feeding glycerol and the critical concentration of glycerol for occurring impulse are the control variables,to formulate 1,3-propanediol(1,3-PD)fed-batch production process.We also discuss a quantity of important properties for this control system.Then,we analyze the sensitivity of system state with respect to the kinetic parameters.We further propose a constrained optimal control model governed by the control system with state-dependent impulses.The existence of the optimal impulsive controls is established.For solving this problem,we utilize an exact penalty method to transform the problem into an optimization problem with only box constraints.Moreover,an improved differential evolution method is developed to seek the optimal impulsive strategy.Finally,numerical simulation results demonstrate that,by using the optimal impulsive strategies,final 1,3-PD concentration is considerably increased under the nominal parameter values and disturbances of kinetic parameters have significant effects on the optimal final 1,3-PD yield.
