Melanins are widely used in medicine, pharmacology and cosmetics. Different technologies have been used to obtain melanin including： chemical synthesis based on oxidation of tyrosine and its derivatives; extraction f...Melanins are widely used in medicine, pharmacology and cosmetics. Different technologies have been used to obtain melanin including： chemical synthesis based on oxidation of tyrosine and its derivatives; extraction from animal materials; alkaline extraction from plant material; and microbiological synthesis. A few number of works have been published that were focused on purification of water insoluble 3,4-dihy- droxy-phenylalanine-melanins （Kukulianskaia et al., 2002）. The majority of synthetic and natural melanins are insoluble in wa- ter that significantly complicates preparation of pharmacolog- ical and cosmetic preparations. Obtaining of low-cost soluble biotechnological melanin can speed up application of melanin in medicine and other fields. For the first time, melanin-syn-thesizing strain with high level of pigment synthesis - Bacillus thuringiensis was obtained. The ecologically safe technology of biosynthesis, isolation and purification of the bacterial melanin has been elaborated.展开更多
Phosphorus is one of the most important nutrients required to support various kinds of biodegradation processes. As this particular nutrient is not included in the activated sludge model no. 1 （ASM1）, this study ext...Phosphorus is one of the most important nutrients required to support various kinds of biodegradation processes. As this particular nutrient is not included in the activated sludge model no. 1 （ASM1）, this study extended this model in order to determine the fate of phosphorus during the biodegradation processes. When some of the kinetics parameters are modified using observed data from the restoration project of the Xuxi River in Wuxi City, China, from August 25 to 31 in 2009, the extended model shows excellent results. In order to obtain optimum values of coefficients of nitrogen and phosphorus, the mass fraction method was used to ensure that the final results were reasonable and practically relevant. The temporal distribution of the data calculated with the extended ASM1 approximates that of the observed data.展开更多
Microbiological experiments show that the colonies of the bacterium bacillus subtilis placed on a dish filled with an agar medium and nutrient form varied spatial patterns while the individual cells grow, reproduce an...Microbiological experiments show that the colonies of the bacterium bacillus subtilis placed on a dish filled with an agar medium and nutrient form varied spatial patterns while the individual cells grow, reproduce and migrate on the dish in clumps. In this paper, we discuss a system of reaction-diffusion equations that can be used with a view to modelling this phenomenon and we solve it numerically by means of the method of lines. For the spatial discretization, we use the finite difference method and Galerkin finite element method. We present how the spatial patterns obtained depend on the spatial discretization employed and we measure the experimental order of convergence of the numerical schemes used. Further, we present the numerical results obtained by solving the model in a cubic domain.展开更多
Acute epididymitis represents a common medical condition in the urological outpatient clinic. Mostly, epididymitis is caused by bacterial ascent through the urogenital tract, with pathogens originating either from sex...Acute epididymitis represents a common medical condition in the urological outpatient clinic. Mostly, epididymitis is caused by bacterial ascent through the urogenital tract, with pathogens originating either from sexually transmitted diseases or urinary tract infections. Although conservative antimicrobial therapy is possible in the majority of patients and is usually sufficient to eradicate the pathogen, studies have shown persistent oligozoospermia and azoospermia in up to 40% of these patients. Animal models of epididymitis are created to delineate the underlying reasons for this observation and the additional impairment of sperm function that is often associated with the disease. Accumulated data provide evidence of a differential expression of immune cells, immunoregulatory genes and pathogen-sensing molecules along the length of the epididymal duct. The evidence suggests that a tolerogenic environment exists in the caput epididymidis, but that inflammatory responses are most intense toward the cauda epididymidis. This is consistent with the need to provide protection for the neo-antigens of spermatozoa emerging from the testis, without compromising the ability to respond to ascending infections. However, severe inflammatory responses, particularly in the cauda, may lead to collateral damage to the structure and function of the epididymis. Convergence of the clinical observations with appropriate animal studies should lead to better understanding of the immunological environment throughout the epididymis, the parameters underlying susceptibility to epididymitis, and to therapeutic approaches that can mitigate epididymal damage and subsequent fertility problems.展开更多
This study was conducted to investigate the effects of extracts of 4 Tibetan veterinary drugs on bacterial diarrhea, and to guide the clinical treatment of the disease. The inhibitory effects of the extracts of the 4 ...This study was conducted to investigate the effects of extracts of 4 Tibetan veterinary drugs on bacterial diarrhea, and to guide the clinical treatment of the disease. The inhibitory effects of the extracts of the 4 Tibetan veterinary drugs, Veronica ciliate Fisch, Usnea diffracta Vain, Sophoraflavescens var. flavescens, Lamiophlomis rotata （ Benth. ） Kudo on 14 common diarrheagenic bacteria were detected by K-B diffusion method and micro-broth dilution method. Optimization was performed on prescriptions of the 4 Tibetan veterinary drugs using orthogonal design software, and a mouse bacterial diarrhea model was established with a clinical isolate, Salmonella blegdam. According to the LD50 value of the optimal prescription of the 4 Tibetan veterinary drugs, the established mouse bacterial diarrhea model was treated in 3 dose groups, i. e. , the high, middle and low dose groups （0. 060, 0. 030 and 0. 020 g/ml, respectively）. The results showed that the 4 Tibetan veterinary drugs had very good inhibitory effects on most of the tested diarrheagenic bacteria, and among them, U. diffracta had better inhibitory effects on all the tested bacteria. The optimal prescription of the d Tibetan veterinary drugs （high dose, 0.06 g/ml） exhibited very good inhibitory effect on mouse diarrhea, indicating that the prescription has very good anti-diarrhea effect, which is beneficial to the clinical treatment of such disease and the development of Tibetan veterinary drugs.展开更多
文摘Melanins are widely used in medicine, pharmacology and cosmetics. Different technologies have been used to obtain melanin including： chemical synthesis based on oxidation of tyrosine and its derivatives; extraction from animal materials; alkaline extraction from plant material; and microbiological synthesis. A few number of works have been published that were focused on purification of water insoluble 3,4-dihy- droxy-phenylalanine-melanins （Kukulianskaia et al., 2002）. The majority of synthetic and natural melanins are insoluble in wa- ter that significantly complicates preparation of pharmacolog- ical and cosmetic preparations. Obtaining of low-cost soluble biotechnological melanin can speed up application of melanin in medicine and other fields. For the first time, melanin-syn-thesizing strain with high level of pigment synthesis - Bacillus thuringiensis was obtained. The ecologically safe technology of biosynthesis, isolation and purification of the bacterial melanin has been elaborated.
文摘Phosphorus is one of the most important nutrients required to support various kinds of biodegradation processes. As this particular nutrient is not included in the activated sludge model no. 1 （ASM1）, this study extended this model in order to determine the fate of phosphorus during the biodegradation processes. When some of the kinetics parameters are modified using observed data from the restoration project of the Xuxi River in Wuxi City, China, from August 25 to 31 in 2009, the extended model shows excellent results. In order to obtain optimum values of coefficients of nitrogen and phosphorus, the mass fraction method was used to ensure that the final results were reasonable and practically relevant. The temporal distribution of the data calculated with the extended ASM1 approximates that of the observed data.
基金The projects “Applied Mathematics in Physics and Technical Sciences” number MSM684077 0010 of the Ministry of Education Youth and Sports of the Czech Republic and “Advanced Supercomputing Methods for Implementation of Mathematical Models” number SGS11/161/OHK4/3T/14
文摘Microbiological experiments show that the colonies of the bacterium bacillus subtilis placed on a dish filled with an agar medium and nutrient form varied spatial patterns while the individual cells grow, reproduce and migrate on the dish in clumps. In this paper, we discuss a system of reaction-diffusion equations that can be used with a view to modelling this phenomenon and we solve it numerically by means of the method of lines. For the spatial discretization, we use the finite difference method and Galerkin finite element method. We present how the spatial patterns obtained depend on the spatial discretization employed and we measure the experimental order of convergence of the numerical schemes used. Further, we present the numerical results obtained by solving the model in a cubic domain.
文摘Acute epididymitis represents a common medical condition in the urological outpatient clinic. Mostly, epididymitis is caused by bacterial ascent through the urogenital tract, with pathogens originating either from sexually transmitted diseases or urinary tract infections. Although conservative antimicrobial therapy is possible in the majority of patients and is usually sufficient to eradicate the pathogen, studies have shown persistent oligozoospermia and azoospermia in up to 40% of these patients. Animal models of epididymitis are created to delineate the underlying reasons for this observation and the additional impairment of sperm function that is often associated with the disease. Accumulated data provide evidence of a differential expression of immune cells, immunoregulatory genes and pathogen-sensing molecules along the length of the epididymal duct. The evidence suggests that a tolerogenic environment exists in the caput epididymidis, but that inflammatory responses are most intense toward the cauda epididymidis. This is consistent with the need to provide protection for the neo-antigens of spermatozoa emerging from the testis, without compromising the ability to respond to ascending infections. However, severe inflammatory responses, particularly in the cauda, may lead to collateral damage to the structure and function of the epididymis. Convergence of the clinical observations with appropriate animal studies should lead to better understanding of the immunological environment throughout the epididymis, the parameters underlying susceptibility to epididymitis, and to therapeutic approaches that can mitigate epididymal damage and subsequent fertility problems.
基金Supported by the Science and Technology Training Plan Project of Sichuan Province(2016KZ0007)the Fundamental Research Funds for the Central Universitiesof Southwest University for Nationalities(2017NZYQN38)
文摘This study was conducted to investigate the effects of extracts of 4 Tibetan veterinary drugs on bacterial diarrhea, and to guide the clinical treatment of the disease. The inhibitory effects of the extracts of the 4 Tibetan veterinary drugs, Veronica ciliate Fisch, Usnea diffracta Vain, Sophoraflavescens var. flavescens, Lamiophlomis rotata （ Benth. ） Kudo on 14 common diarrheagenic bacteria were detected by K-B diffusion method and micro-broth dilution method. Optimization was performed on prescriptions of the 4 Tibetan veterinary drugs using orthogonal design software, and a mouse bacterial diarrhea model was established with a clinical isolate, Salmonella blegdam. According to the LD50 value of the optimal prescription of the 4 Tibetan veterinary drugs, the established mouse bacterial diarrhea model was treated in 3 dose groups, i. e. , the high, middle and low dose groups （0. 060, 0. 030 and 0. 020 g/ml, respectively）. The results showed that the 4 Tibetan veterinary drugs had very good inhibitory effects on most of the tested diarrheagenic bacteria, and among them, U. diffracta had better inhibitory effects on all the tested bacteria. The optimal prescription of the d Tibetan veterinary drugs （high dose, 0.06 g/ml） exhibited very good inhibitory effect on mouse diarrhea, indicating that the prescription has very good anti-diarrhea effect, which is beneficial to the clinical treatment of such disease and the development of Tibetan veterinary drugs.
