Combined with the parameters of the production process of a steel factory, numerical simulations for a new ladle from preheating to turnover are conducted using the finite element analysis system software （ANSYS）. T...Combined with the parameters of the production process of a steel factory, numerical simulations for a new ladle from preheating to turnover are conducted using the finite element analysis system software （ANSYS）. The measured data proved that the simulated results are reliable. The effects of preheating time, thermal cycling times, and empty package time on steel temperature are calculated, an ideal preheating time is provided, besides, based on the analysis of a single factor and use the nonlinear analysis method, a steel temperature compensating model with di- versified coupling factors is proposed, with the largest error of the present coupling model at 1. 462 ~C, and the er- rors between actual and target steel temperature in tundish after the model is applied to practical production are basi- cally controlled within -4-6 ~C, which can meet the accuracy of the manufacturer and has a practical guiding significance for the production in steelmaking workshops.展开更多
Based on the characteristics of atom types, Hall＇s electrotopological state indices （En） are calculated for 165 nonionic organic compounds. On the basis of the characteristics of substituent and conjugated matrix, ...Based on the characteristics of atom types, Hall＇s electrotopological state indices （En） are calculated for 165 nonionic organic compounds. On the basis of the characteristics of substituent and conjugated matrix, a novel molecular structure parameter （G） is defined and calculated for 165 molecules in this paper. En and G show good structural selectivity for organic molecules. G, a satisfactory relationship between bioconcentration factor （BCF） and En, is expressed as： 1gBCF = -0.283 ＋ 1.246G ＋ 0.079E42 ＋ 0.351E9- 0.063E17 （n＇ = 122, R = 0.967, F = 425.636, s = 0.394）, which could provide estimation and prediction for the lgBCF of nonionic organic chemicals. Furthermore, the model is examined to validate overall robustness with Jackknife tests, and the independent variables in model do not exist cross correlation with VIF. All these regression results show that the new parameter G and electrotopological state index have good rationality and efficiency. It is concluded that the En and G will be used widely in quantitative structure-property/activity relationship （QSPR/QSAR） research.展开更多
Direct calculations of unsteady-state Weymouth equations for gas volumetric flow rate occur more frequently in the design and operation analysis of natural gas systems. Most of the existing gas pipelines design proced...Direct calculations of unsteady-state Weymouth equations for gas volumetric flow rate occur more frequently in the design and operation analysis of natural gas systems. Most of the existing gas pipelines design procedures are based on a particular friction factor and steady-state flow analysis. This paper examined the behavior of different friction factors and the need to develop model analysis capable of calculating unsteady-state gas flow rate in horizontal and inclined pipes. The results show different variation in flow rate with Panhandle A and Panhandle B attaining stability in accurate time with initial unsteadiness at the instance of flow. Chen and Jain friction factors have opposition to flow with high flow rate: The prediction also reveals that Colebrook-White degenerated to Nikuradse friction factor at high Reynolds number. The horizontal and inclined flow equations are considerably enhanced on the usage of different friction factors with the aid of Matlab to handle these calculations.展开更多
Through the study of the factorization conditions of a wave function made up of two, three and four qubits, we propose an analytical expression which can characterize entangled states in terms of the coefficients of t...Through the study of the factorization conditions of a wave function made up of two, three and four qubits, we propose an analytical expression which can characterize entangled states in terms of the coefficients of the wave function and density matrix elements.展开更多
Objective: To investigate the effect of acupuncture on high hemagglutination state, blood sugar raising hormone and immunocyte factor levels in type II diabetes patients. Methods: A total of 120 inpatients and outpati...Objective: To investigate the effect of acupuncture on high hemagglutination state, blood sugar raising hormone and immunocyte factor levels in type II diabetes patients. Methods: A total of 120 inpatients and outpatients were randomly divided into acupuncture plus medication group (n=52) and medication group (n=50). In addition, 18 type II diabetes patients formed acupuncture group for comparing their therapeutic effects. Main acupoints used were Pishu (BL 20), Geshu (BL 17), Yishu, Shenshu (BL 23), Zusanli (ST 36), Sanyinjiao (SP 6), etc.. combined with other acupoints according to different sydroms. These acupoints were stimulated by manipulaing the filiform needles with uniform reinforcing and reducing method for 15 min and then stimulated electrically for 15 min with an electroacupuncture therapeutic apparatus. Western medicines used were Glipizide, Dimethyldiguanide Hydrochloride, etc.. The treatment was given once daily, with 10 sessions being a therapeutic course, 2～3 courses altogether. Indexes of external thrombosis length (ETL), platelet agglutination rate (PAgR), fibrinogen (FG), activated partial thromboplastin time (APTT), fasting blood glucose (FBG), prothrombin time(PT), adrenocoticortropic hormone (ACTH), cortisol (CS), growth hormone (GH), glucagon (GL), tumor necrosis factor alpha (TNF α), interleukin 6 (IL 6), insulin (INS) and C peptide (C P) were determined using radioimmunoassay. Results: After 2～3 courses of treatment, both acupuncture group and medication plus acupuncture group could significantly improve high hemagglutination state, lower blood sugar raising hormone level, regulate immunocyte factor level and raise the sensitivity of insulin, which were apparently superior to those of medication group (P<0.05～0.01). Conclusion: Acupuncture therapy can effectively regulate plasma blood sugar raising hormone, immunocyte factor levels, increase the sensitivity of insulin to target cells, resist blood coagulation and improve microcirculation.展开更多
Aim: The study aimed at evaluating the seroprevalence of H. pylori infection and its associated risk factors in a cross-section of asymptomatic adult population in Niger-Delta, Nigeria. Methodology: 408 apparently hea...Aim: The study aimed at evaluating the seroprevalence of H. pylori infection and its associated risk factors in a cross-section of asymptomatic adult population in Niger-Delta, Nigeria. Methodology: 408 apparently healthy volunteers, aged between 18 - 87 years were recruited for this study. Blood samples were collected from participants and analyzed for H. pylori antibody (IgG) qualitatively with Combo rapid kits and quantitatively with Accu-Bind ELISA Kits. Results: The overall prevalence of Helicobacter pylori colonization in 408 asymptomatic adults was 52.5% (n = 214) and 48.3% (n = 197) by qualitative (Combo rapid kits) and quantitative (Accu-Bind ELISA Kits) serological test methods respectively. H. pylori infection did not differ statistically between genders (p = 0.962) and among age groups (p = 0.185). In addition, multivariate logistic regression indicated that sex and age were not associated with risk of H. pylori. However, participants from Delta Central were at greater risk (OR = 1.89;p = 0.014) of H. pylori infection compared with those from Delta South, but those from Delta North were not at greater risk of infection compared with those from Delta South (p = 0.476). Conclusion: This study indicated an intermediate seroprevalence of H. pylori among asymptomatic adults in Delta state, Nigeria. The prevalence of H. pylori infection was linked to geographical regions but not with sex and age.展开更多
Peste des petits ruminant (PPR) is a contagious disease of small ruminants caused by a virus that belongs to the genus Morbillivirus of the family Paramyxoviridae. This study aimed to determine the seroprevalence of P...Peste des petits ruminant (PPR) is a contagious disease of small ruminants caused by a virus that belongs to the genus Morbillivirus of the family Paramyxoviridae. This study aimed to determine the seroprevalence of PPR disease in sheep and goats and its associated risk factors in Kassala State, Eastern Sudan. Across sectional study was conducted during the period from 30th August to 25th November 2015. The study was carried out using a structured questionnaire survey and a total of 918 blood samples were collected from apparently healthy unvaccinated sheep and goats in different localities in State of Kassala. A total of 546 sheep and 372 goats were tested for specific antibodies to nucleoprotein (NP) by competitive enzyme linked immunosorbent assay (cELISA). The apparent overall prevalence of PPR antibodies in Kassala was 58.2% while the true prevalence was calculated to be 61.3%. The apparent prevalence in sheep and goats was 68.1% and 43.5% respectively. Univariate analysis showed that the risk factors had significant associations with a cELISA positive status: locality, species, age, breed, husbandry system, housing mode, animals movement (p = 0.000) and animals sharing pasture and water (p = 0.003), while sex and newly introduced animals were not significant risk factors (p = 0.771) (p = 0.050) respectively. Factors found that significantly associated (p < 0.05) with increased odds of being cELISA positive in multivariate analysis were localities, species, age and newly introduced animals. The prevalence differed between localities and was the highest in the River Atbara (84.0%) locality, whereas it was lowest in Delta North (29.0%). No significant difference was observed among the sexes. However, the prevalence differed in different age groups and was 52.25% in animals of less than six months old;49.3% were between seven months and two years old and 65.5% were above two years old. In different husbandry systems, the prevalence was 47.9%, 73.0% and 49.2% in intensive, open grazing and pastoral systems respectively. Housing type effects were also observed;the highest prevalence was in animals housed in metal fence (83.3%). The movement pattern showed significant effect, where the prevalence was the highest (81.3%) in animals that move inter-states/inter-localities. It is concluded that the disease is endemic in Kassala State, high prevalent in sheep and goats, posing a threat to animal exportation, and may have a serious economic influence. Owners and herders should compulsorily vaccinate their animals yearly and animals should be investigated periodically for implementation of crucial eradication program.展开更多
By analyzing the importance of influencing factors and conducting a comparative study of the effects of different sorting algorithms, a new method is proposed that is suitable for classifying the growth state of a nat...By analyzing the importance of influencing factors and conducting a comparative study of the effects of different sorting algorithms, a new method is proposed that is suitable for classifying the growth state of a natural Metasequoia glyptostroboides Hu and W.C. Cheng population. We studied 2817 M. glyptostroboides trees over 100 years old and analyzed their growth state by measuring 15 factors from stumpage, site condition, and environmental data. The dimensionality of all factors were reduced using the random forest algorithm, and we classified the remaining factors using the following algorithms: random forest, back-propagation(BP) neural networks, and support vector machine(SVM). The applicability of each sorting algorithm was analyzed. When all the d factors are used for classification and modeling, the model's overall accuracy,kappa coefficient and test accuracy were 85.5%, 0.739 and 85.8%, respectively. By reducing the dimensionality of the factors using the random forest algorithm, 11 factors most strongly influenced the classifications of the growth state of the Metasequoia population: diameter at breast height,height, crown width, age from stumpage data; longitude,latitude, elevation, slope aspect, gradient and slope position from the site condition data; and the edge of the field from the environmental data. For classifying the Metasequoia population, the random forest algorithm has the highest overall accuracy at 87.2%, which is 3.4 and 2.3% higher than the BP neural networks and SVM algorithms,respectively. The SVM algorithm is superior to the random forest algorithm with respect to classifying the state of mortality. The combination of the random forest and SVM algorithms and their combined information can be used to classify and predict the growth state of this natural M.glyptostroboides population to provide a scientific basis for its effective protection.展开更多
Introduction: Tuberculosis is a major health problem in developing countries including Sudan. Screening for TB cases through Household contacts (HHCs) investigation is an appropriate strategy to interrupt transmission...Introduction: Tuberculosis is a major health problem in developing countries including Sudan. Screening for TB cases through Household contacts (HHCs) investigation is an appropriate strategy to interrupt transmission of TB. Objectives: To determine the prevalence tuberculosis infection and risk factors for tuberculosis infection among household contacts in Wadimadani locality, Central State, Sudan, between November 2015 and April 2016. Methods: An analytical cross-sectional study conducted. During study period, to confirm TB diagnosis, all suspect contacts were tested through sputum samples, tuberculin skin test or chest X-ray. Structured questionnaire was used to collect socio-demographic and environmental factors. Results: One hundred forty six patients of smear-positive pulmonary tuberculosis were included in the study, 657 household contacts were identified and screened. Forty three new TB cases were detected from household contacts, yielding a prevalence of 6.5% (95% confidence interval = 0.05, 0.09) of latent tuberculosis infection (LTBI). Two factors were significantly associated with LTBI among HHCs: duration of contact with a TB patient ≤ 4 months (P = 0.03) and the educational status (P = 0.02). Conclusion: Screening of HHCs of index case of TB will contribute in early detection and treatment of new cases, and considered as a forward step towards eliminating TB.展开更多
Suppose the degenerate states wave function of a Hamitonian operatorHis accompanied by a natural phase factor, then we can own it to the role of sometransformation generator played by some non--degenerate Hermitian op...Suppose the degenerate states wave function of a Hamitonian operatorHis accompanied by a natural phase factor, then we can own it to the role of sometransformation generator played by some non--degenerate Hermitian operator containedin the complete set of conserved mechanical quantities. When this idea is extended tothe spece coordinated by parameters and the momentum--like operator is introduced,thenon-Abelian Berry phose factor of degenerate wave function can be easily gotter afterthe system evolves along a closed adiabatic curve.展开更多
BACKGROUND： Vascular endothelial growth factor （VEGF） is able to regulate blood spinal cord barrier function as well as influence neovascularization and cause edema. OBJECTIVE： Through establishment of a rabbit mo...BACKGROUND： Vascular endothelial growth factor （VEGF） is able to regulate blood spinal cord barrier function as well as influence neovascularization and cause edema. OBJECTIVE： Through establishment of a rabbit model of syringomyelia, to explore the correlation between VEGF protein and mRNA expressions and function of blood spinal cord barrier and edema degree of spinal cord in presyrinx state. DESIGN, TIME AND SETTING： Randomized controlled animal study was performed in the Tumor Institute of the Fourth Hospital, Hebei Medical University from January to June 2007. MATERIALS： Atotal of 0.6 mL Kaolin solution （250 g/L, 37℃） was injected into the cisterna magna of 40 rabbits in the kaolin group to establish syringomyelia models. Goat anti-rabbit VEGF monoclonal antibody was provided by DIACLONE Company, USA; RT-PCR related reagents were provided by Huamei Bioengineering Co., Ltd., Beijing. METHODS： Sixty Chinese white rabbits were divided randomly into two groups： Kaolin group （n = 40） and control group （n = 20）. Physiological saline （0.6 mL at 37℃） was injected in rabbits of control group. On days 1,3, 7, 14 and 21 after kaolin injection, cervical cords samples were harvested after sacrifice of animal. MAIN OUTCOME MEASURES： VEGF protein and mRNA expressions were detected by immunohistochemistry and RT-PCR on days 1, 3, 7, 14, and 21 after kaolin injection. A quantitative analysis of blood spinal cord barrier function was performed by Evans blue technique. Water content of the spinal cord was measured by dry-wet weight technique. The correlation between the expression of VEGF protein and mRNA and the function of blood spinal cord barrier in the upper cervical cord of the presyrinx state was analyzed by linear correlation analysis. RESULTS： The water content and Evans blue content increased in the kaolin group on days 1 and 3 postoperatively compared with the control group （F = 7.387, 61.35, P 〈 0.05, 0.01）, and reached a peak on day 7 （F = 135.94, 528.35, P 〈 0.01）. They declined slowly to day 21 postoperatively, but both contents were still higher than the control group （F = 11.51, 58.63, P 〈 0.01）. VEGF protein expression increased on day 1, and stronger positive expression was seen on days 3, 7 and 14. It decreased on day 21. VEGF protein expression was higher than the control group at each time point （F = 137.4-468.5, P 〈 0.01 ）. VEGF mRNA expression showed the same pattern in the cervical cord at different time points. By statistical analysis, the expression of VEGF protein and mRNA had a significantly positive correlation with the structural and functional changes of the blood spinal cord barrier in the presyrinx state （r = 0.604-0.979, P 〈 0.05）. CONCLUSION： In the presyrinx state of syringomyelia, the expressions of VEGF protein and mRNA can influence the structure and function of the blood spinal cord barrier and play an important role in the formation and development of spinal cord edema and syringomyelia.展开更多
In this paper we try to introduce the ladder operators associated with the pseudoharmonic oscillator, after solving the corresponding Schrrdinger equation by using the factorization method. The obtained generalized ra...In this paper we try to introduce the ladder operators associated with the pseudoharmonic oscillator, after solving the corresponding Schrrdinger equation by using the factorization method. The obtained generalized raising and lowering operators naturally lead us to the Dirac representation space of the system which is much easier to work with, in comparison to the functional Hilbert space. The SU（1, 1） dynamical symmetry group associated with the considered system is exactly established through investigating the fact that the deduced operators satisfy appropriate commutation relations. This result enables us to construct two important and distinct classes of Barut-Girardello and Gilmore-Perelomov coherent states associated with the system. Finally, their identities as the most important task are exactly resolved and some of their nonclassical properties are illustrated, numerically.展开更多
食源性细菌感染威胁全球公共卫生,细菌在不利环境下可进入活的不可培养(viable but nonculturable,VBNC)状态,仍可能具有致病性、耐药性,在一定条件下可复苏,会带来食品安全和疾病传播风险。该文聚焦食源性致病菌VBNC状态的成因及危害,...食源性细菌感染威胁全球公共卫生,细菌在不利环境下可进入活的不可培养(viable but nonculturable,VBNC)状态,仍可能具有致病性、耐药性,在一定条件下可复苏,会带来食品安全和疾病传播风险。该文聚焦食源性致病菌VBNC状态的成因及危害,综述了VBNC细菌复苏的影响因素、复苏机制及复苏后生理特性。总结了复苏的主要影响因素,包括物理因素、化学因素和生物因素。复苏机制分为主动复苏(群体感应、复苏促进因子)和被动复苏(补充营养物质、添加抗氧化剂、与宿主细胞共培养),复苏后菌体的形态、结构、代谢功能、生长能力、毒力、抵抗能力几乎恢复到正常水平。展开更多
[ Objective] The paper was to explore the residual dynamics and degradation rule of high concentration carbendazim in natural condition. [ Method J The earbendasim solutions with mass fractions of 0.2% （ recommended ...[ Objective] The paper was to explore the residual dynamics and degradation rule of high concentration carbendazim in natural condition. [ Method J The earbendasim solutions with mass fractions of 0.2% （ recommended concentration）, 0.4% （2 times of the recommended concentration） and I. 0% （5 times of the recommended concentration） were sprayed on plant leaves, and the residual amount of earbendazim in natural condition was determined. The dynamic models of carbendazim residues Under 3 concentrations were also studied. [ Result~ The degradation of earbcndazim under recommended concentration was accorded with Kinetic model for degradation, but the degradation Kinetic model for samples under 2 times and 5 times concentration appeared dissimilation. The residue of carben- dazim on plant was affected by absorption capacity of plants and weather conditions. The absorption capacity was affected by application concentration and growth condition of plant, higher concentration application and slow growth stage of p]ant were not conducive to the absorption of carbendazim; weather condition was mainly referred to temperature and humidity, higher temperature and dry weather were not conducive to the degradation of earbendazim. [Condusion ] The paper provided theoretical basis for guiding the application of carbendazim under different growth stages of crops and different weather conditions in agricultural production.展开更多
基金Item Sponsored by Technology Supporting Program During the 11th Five-Year Plan Period(BAE03A07)
文摘Combined with the parameters of the production process of a steel factory, numerical simulations for a new ladle from preheating to turnover are conducted using the finite element analysis system software （ANSYS）. The measured data proved that the simulated results are reliable. The effects of preheating time, thermal cycling times, and empty package time on steel temperature are calculated, an ideal preheating time is provided, besides, based on the analysis of a single factor and use the nonlinear analysis method, a steel temperature compensating model with di- versified coupling factors is proposed, with the largest error of the present coupling model at 1. 462 ~C, and the er- rors between actual and target steel temperature in tundish after the model is applied to practical production are basi- cally controlled within -4-6 ~C, which can meet the accuracy of the manufacturer and has a practical guiding significance for the production in steelmaking workshops.
基金the State Key Laboratory of Pollution Control and Reuse of China Project Proposal (PCRRF07009)the University Natural Science Foundation of Jiangsu Province (05KJD150221)Natural Science Incubation Foundation of Xuzhou Normal University (05PLY04)
文摘Based on the characteristics of atom types, Hall＇s electrotopological state indices （En） are calculated for 165 nonionic organic compounds. On the basis of the characteristics of substituent and conjugated matrix, a novel molecular structure parameter （G） is defined and calculated for 165 molecules in this paper. En and G show good structural selectivity for organic molecules. G, a satisfactory relationship between bioconcentration factor （BCF） and En, is expressed as： 1gBCF = -0.283 ＋ 1.246G ＋ 0.079E42 ＋ 0.351E9- 0.063E17 （n＇ = 122, R = 0.967, F = 425.636, s = 0.394）, which could provide estimation and prediction for the lgBCF of nonionic organic chemicals. Furthermore, the model is examined to validate overall robustness with Jackknife tests, and the independent variables in model do not exist cross correlation with VIF. All these regression results show that the new parameter G and electrotopological state index have good rationality and efficiency. It is concluded that the En and G will be used widely in quantitative structure-property/activity relationship （QSPR/QSAR） research.
文摘Direct calculations of unsteady-state Weymouth equations for gas volumetric flow rate occur more frequently in the design and operation analysis of natural gas systems. Most of the existing gas pipelines design procedures are based on a particular friction factor and steady-state flow analysis. This paper examined the behavior of different friction factors and the need to develop model analysis capable of calculating unsteady-state gas flow rate in horizontal and inclined pipes. The results show different variation in flow rate with Panhandle A and Panhandle B attaining stability in accurate time with initial unsteadiness at the instance of flow. Chen and Jain friction factors have opposition to flow with high flow rate: The prediction also reveals that Colebrook-White degenerated to Nikuradse friction factor at high Reynolds number. The horizontal and inclined flow equations are considerably enhanced on the usage of different friction factors with the aid of Matlab to handle these calculations.
文摘Through the study of the factorization conditions of a wave function made up of two, three and four qubits, we propose an analytical expression which can characterize entangled states in terms of the coefficients of the wave function and density matrix elements.
文摘Objective: To investigate the effect of acupuncture on high hemagglutination state, blood sugar raising hormone and immunocyte factor levels in type II diabetes patients. Methods: A total of 120 inpatients and outpatients were randomly divided into acupuncture plus medication group (n=52) and medication group (n=50). In addition, 18 type II diabetes patients formed acupuncture group for comparing their therapeutic effects. Main acupoints used were Pishu (BL 20), Geshu (BL 17), Yishu, Shenshu (BL 23), Zusanli (ST 36), Sanyinjiao (SP 6), etc.. combined with other acupoints according to different sydroms. These acupoints were stimulated by manipulaing the filiform needles with uniform reinforcing and reducing method for 15 min and then stimulated electrically for 15 min with an electroacupuncture therapeutic apparatus. Western medicines used were Glipizide, Dimethyldiguanide Hydrochloride, etc.. The treatment was given once daily, with 10 sessions being a therapeutic course, 2～3 courses altogether. Indexes of external thrombosis length (ETL), platelet agglutination rate (PAgR), fibrinogen (FG), activated partial thromboplastin time (APTT), fasting blood glucose (FBG), prothrombin time(PT), adrenocoticortropic hormone (ACTH), cortisol (CS), growth hormone (GH), glucagon (GL), tumor necrosis factor alpha (TNF α), interleukin 6 (IL 6), insulin (INS) and C peptide (C P) were determined using radioimmunoassay. Results: After 2～3 courses of treatment, both acupuncture group and medication plus acupuncture group could significantly improve high hemagglutination state, lower blood sugar raising hormone level, regulate immunocyte factor level and raise the sensitivity of insulin, which were apparently superior to those of medication group (P<0.05～0.01). Conclusion: Acupuncture therapy can effectively regulate plasma blood sugar raising hormone, immunocyte factor levels, increase the sensitivity of insulin to target cells, resist blood coagulation and improve microcirculation.
文摘Aim: The study aimed at evaluating the seroprevalence of H. pylori infection and its associated risk factors in a cross-section of asymptomatic adult population in Niger-Delta, Nigeria. Methodology: 408 apparently healthy volunteers, aged between 18 - 87 years were recruited for this study. Blood samples were collected from participants and analyzed for H. pylori antibody (IgG) qualitatively with Combo rapid kits and quantitatively with Accu-Bind ELISA Kits. Results: The overall prevalence of Helicobacter pylori colonization in 408 asymptomatic adults was 52.5% (n = 214) and 48.3% (n = 197) by qualitative (Combo rapid kits) and quantitative (Accu-Bind ELISA Kits) serological test methods respectively. H. pylori infection did not differ statistically between genders (p = 0.962) and among age groups (p = 0.185). In addition, multivariate logistic regression indicated that sex and age were not associated with risk of H. pylori. However, participants from Delta Central were at greater risk (OR = 1.89;p = 0.014) of H. pylori infection compared with those from Delta South, but those from Delta North were not at greater risk of infection compared with those from Delta South (p = 0.476). Conclusion: This study indicated an intermediate seroprevalence of H. pylori among asymptomatic adults in Delta state, Nigeria. The prevalence of H. pylori infection was linked to geographical regions but not with sex and age.
文摘Peste des petits ruminant (PPR) is a contagious disease of small ruminants caused by a virus that belongs to the genus Morbillivirus of the family Paramyxoviridae. This study aimed to determine the seroprevalence of PPR disease in sheep and goats and its associated risk factors in Kassala State, Eastern Sudan. Across sectional study was conducted during the period from 30th August to 25th November 2015. The study was carried out using a structured questionnaire survey and a total of 918 blood samples were collected from apparently healthy unvaccinated sheep and goats in different localities in State of Kassala. A total of 546 sheep and 372 goats were tested for specific antibodies to nucleoprotein (NP) by competitive enzyme linked immunosorbent assay (cELISA). The apparent overall prevalence of PPR antibodies in Kassala was 58.2% while the true prevalence was calculated to be 61.3%. The apparent prevalence in sheep and goats was 68.1% and 43.5% respectively. Univariate analysis showed that the risk factors had significant associations with a cELISA positive status: locality, species, age, breed, husbandry system, housing mode, animals movement (p = 0.000) and animals sharing pasture and water (p = 0.003), while sex and newly introduced animals were not significant risk factors (p = 0.771) (p = 0.050) respectively. Factors found that significantly associated (p < 0.05) with increased odds of being cELISA positive in multivariate analysis were localities, species, age and newly introduced animals. The prevalence differed between localities and was the highest in the River Atbara (84.0%) locality, whereas it was lowest in Delta North (29.0%). No significant difference was observed among the sexes. However, the prevalence differed in different age groups and was 52.25% in animals of less than six months old;49.3% were between seven months and two years old and 65.5% were above two years old. In different husbandry systems, the prevalence was 47.9%, 73.0% and 49.2% in intensive, open grazing and pastoral systems respectively. Housing type effects were also observed;the highest prevalence was in animals housed in metal fence (83.3%). The movement pattern showed significant effect, where the prevalence was the highest (81.3%) in animals that move inter-states/inter-localities. It is concluded that the disease is endemic in Kassala State, high prevalent in sheep and goats, posing a threat to animal exportation, and may have a serious economic influence. Owners and herders should compulsorily vaccinate their animals yearly and animals should be investigated periodically for implementation of crucial eradication program.
基金supported by Study on Spatial Environmental Effect Model and Forestation Decision Support System for Forest Vegetation in Beijing(6161001)
文摘By analyzing the importance of influencing factors and conducting a comparative study of the effects of different sorting algorithms, a new method is proposed that is suitable for classifying the growth state of a natural Metasequoia glyptostroboides Hu and W.C. Cheng population. We studied 2817 M. glyptostroboides trees over 100 years old and analyzed their growth state by measuring 15 factors from stumpage, site condition, and environmental data. The dimensionality of all factors were reduced using the random forest algorithm, and we classified the remaining factors using the following algorithms: random forest, back-propagation(BP) neural networks, and support vector machine(SVM). The applicability of each sorting algorithm was analyzed. When all the d factors are used for classification and modeling, the model's overall accuracy,kappa coefficient and test accuracy were 85.5%, 0.739 and 85.8%, respectively. By reducing the dimensionality of the factors using the random forest algorithm, 11 factors most strongly influenced the classifications of the growth state of the Metasequoia population: diameter at breast height,height, crown width, age from stumpage data; longitude,latitude, elevation, slope aspect, gradient and slope position from the site condition data; and the edge of the field from the environmental data. For classifying the Metasequoia population, the random forest algorithm has the highest overall accuracy at 87.2%, which is 3.4 and 2.3% higher than the BP neural networks and SVM algorithms,respectively. The SVM algorithm is superior to the random forest algorithm with respect to classifying the state of mortality. The combination of the random forest and SVM algorithms and their combined information can be used to classify and predict the growth state of this natural M.glyptostroboides population to provide a scientific basis for its effective protection.
文摘Introduction: Tuberculosis is a major health problem in developing countries including Sudan. Screening for TB cases through Household contacts (HHCs) investigation is an appropriate strategy to interrupt transmission of TB. Objectives: To determine the prevalence tuberculosis infection and risk factors for tuberculosis infection among household contacts in Wadimadani locality, Central State, Sudan, between November 2015 and April 2016. Methods: An analytical cross-sectional study conducted. During study period, to confirm TB diagnosis, all suspect contacts were tested through sputum samples, tuberculin skin test or chest X-ray. Structured questionnaire was used to collect socio-demographic and environmental factors. Results: One hundred forty six patients of smear-positive pulmonary tuberculosis were included in the study, 657 household contacts were identified and screened. Forty three new TB cases were detected from household contacts, yielding a prevalence of 6.5% (95% confidence interval = 0.05, 0.09) of latent tuberculosis infection (LTBI). Two factors were significantly associated with LTBI among HHCs: duration of contact with a TB patient ≤ 4 months (P = 0.03) and the educational status (P = 0.02). Conclusion: Screening of HHCs of index case of TB will contribute in early detection and treatment of new cases, and considered as a forward step towards eliminating TB.
文摘Suppose the degenerate states wave function of a Hamitonian operatorHis accompanied by a natural phase factor, then we can own it to the role of sometransformation generator played by some non--degenerate Hermitian operator containedin the complete set of conserved mechanical quantities. When this idea is extended tothe spece coordinated by parameters and the momentum--like operator is introduced,thenon-Abelian Berry phose factor of degenerate wave function can be easily gotter afterthe system evolves along a closed adiabatic curve.
文摘BACKGROUND： Vascular endothelial growth factor （VEGF） is able to regulate blood spinal cord barrier function as well as influence neovascularization and cause edema. OBJECTIVE： Through establishment of a rabbit model of syringomyelia, to explore the correlation between VEGF protein and mRNA expressions and function of blood spinal cord barrier and edema degree of spinal cord in presyrinx state. DESIGN, TIME AND SETTING： Randomized controlled animal study was performed in the Tumor Institute of the Fourth Hospital, Hebei Medical University from January to June 2007. MATERIALS： Atotal of 0.6 mL Kaolin solution （250 g/L, 37℃） was injected into the cisterna magna of 40 rabbits in the kaolin group to establish syringomyelia models. Goat anti-rabbit VEGF monoclonal antibody was provided by DIACLONE Company, USA; RT-PCR related reagents were provided by Huamei Bioengineering Co., Ltd., Beijing. METHODS： Sixty Chinese white rabbits were divided randomly into two groups： Kaolin group （n = 40） and control group （n = 20）. Physiological saline （0.6 mL at 37℃） was injected in rabbits of control group. On days 1,3, 7, 14 and 21 after kaolin injection, cervical cords samples were harvested after sacrifice of animal. MAIN OUTCOME MEASURES： VEGF protein and mRNA expressions were detected by immunohistochemistry and RT-PCR on days 1, 3, 7, 14, and 21 after kaolin injection. A quantitative analysis of blood spinal cord barrier function was performed by Evans blue technique. Water content of the spinal cord was measured by dry-wet weight technique. The correlation between the expression of VEGF protein and mRNA and the function of blood spinal cord barrier in the upper cervical cord of the presyrinx state was analyzed by linear correlation analysis. RESULTS： The water content and Evans blue content increased in the kaolin group on days 1 and 3 postoperatively compared with the control group （F = 7.387, 61.35, P 〈 0.05, 0.01）, and reached a peak on day 7 （F = 135.94, 528.35, P 〈 0.01）. They declined slowly to day 21 postoperatively, but both contents were still higher than the control group （F = 11.51, 58.63, P 〈 0.01）. VEGF protein expression increased on day 1, and stronger positive expression was seen on days 3, 7 and 14. It decreased on day 21. VEGF protein expression was higher than the control group at each time point （F = 137.4-468.5, P 〈 0.01 ）. VEGF mRNA expression showed the same pattern in the cervical cord at different time points. By statistical analysis, the expression of VEGF protein and mRNA had a significantly positive correlation with the structural and functional changes of the blood spinal cord barrier in the presyrinx state （r = 0.604-0.979, P 〈 0.05）. CONCLUSION： In the presyrinx state of syringomyelia, the expressions of VEGF protein and mRNA can influence the structure and function of the blood spinal cord barrier and play an important role in the formation and development of spinal cord edema and syringomyelia.
文摘In this paper we try to introduce the ladder operators associated with the pseudoharmonic oscillator, after solving the corresponding Schrrdinger equation by using the factorization method. The obtained generalized raising and lowering operators naturally lead us to the Dirac representation space of the system which is much easier to work with, in comparison to the functional Hilbert space. The SU（1, 1） dynamical symmetry group associated with the considered system is exactly established through investigating the fact that the deduced operators satisfy appropriate commutation relations. This result enables us to construct two important and distinct classes of Barut-Girardello and Gilmore-Perelomov coherent states associated with the system. Finally, their identities as the most important task are exactly resolved and some of their nonclassical properties are illustrated, numerically.
文摘食源性细菌感染威胁全球公共卫生,细菌在不利环境下可进入活的不可培养(viable but nonculturable,VBNC)状态,仍可能具有致病性、耐药性,在一定条件下可复苏,会带来食品安全和疾病传播风险。该文聚焦食源性致病菌VBNC状态的成因及危害,综述了VBNC细菌复苏的影响因素、复苏机制及复苏后生理特性。总结了复苏的主要影响因素,包括物理因素、化学因素和生物因素。复苏机制分为主动复苏(群体感应、复苏促进因子)和被动复苏(补充营养物质、添加抗氧化剂、与宿主细胞共培养),复苏后菌体的形态、结构、代谢功能、生长能力、毒力、抵抗能力几乎恢复到正常水平。
基金Supported by International Science and Technology Cooperation Project of Changzhou City ( CZ20100028)~~
文摘[ Objective] The paper was to explore the residual dynamics and degradation rule of high concentration carbendazim in natural condition. [ Method J The earbendasim solutions with mass fractions of 0.2% （ recommended concentration）, 0.4% （2 times of the recommended concentration） and I. 0% （5 times of the recommended concentration） were sprayed on plant leaves, and the residual amount of earbendazim in natural condition was determined. The dynamic models of carbendazim residues Under 3 concentrations were also studied. [ Result~ The degradation of earbcndazim under recommended concentration was accorded with Kinetic model for degradation, but the degradation Kinetic model for samples under 2 times and 5 times concentration appeared dissimilation. The residue of carben- dazim on plant was affected by absorption capacity of plants and weather conditions. The absorption capacity was affected by application concentration and growth condition of plant, higher concentration application and slow growth stage of p]ant were not conducive to the absorption of carbendazim; weather condition was mainly referred to temperature and humidity, higher temperature and dry weather were not conducive to the degradation of earbendazim. [Condusion ] The paper provided theoretical basis for guiding the application of carbendazim under different growth stages of crops and different weather conditions in agricultural production.
