[Objective] This study aimed to establish a method for quantitative detection of mRNA transcriptional level of SS2 adhesive related-factors of Streptococcus suis serotype 2 （SS2） by fluorescent quantitative PCR. []V...[Objective] This study aimed to establish a method for quantitative detection of mRNA transcriptional level of SS2 adhesive related-factors of Streptococcus suis serotype 2 （SS2） by fluorescent quantitative PCR. []Vlethod] The gene fragments en- coding SS2 adhesive related-factors MRP, FBPS and CPS2J and a housekeeping gene aroA were amplified by reverse transcription PCR from the total RNA of SS2, cloned, and sequenced. The recombinant plasmids containing the target genes were constructed, and used as templates in Real-time PCR. [Result] Dynamic curves, stan- dard curves and melting curves of the adhesive related-factors and aroA were ob- tained by the optimized Real-time PCR system. The standard curves showed a good linear relationship between template copy number and circulation number, and the correlation coefficients （FF） of the standard curves were over 0.995. Also, these as- says were highly specific a^d there was single specific melting peak for every gene. Moreover, the assays were highly sensitive and had a detection limit of 1.0×102 copies in 1 μl of initial templates. Finally, it was highly repeatable and had a coeffi- cient of variation less than 2% for intra-assay. [Conclusion] This study will provide a way to reveal the adhesion mechanism of SS2 to different host cells at molecular level.展开更多
This study explored HIV risk perception of university students. A descriptive study design amongst a convenience sample of registered students at the Nelson Mandela Metropolitan University （NMMU）, who gave voluntary...This study explored HIV risk perception of university students. A descriptive study design amongst a convenience sample of registered students at the Nelson Mandela Metropolitan University （NMMU）, who gave voluntary informed consent to participate, and with access to the student portal was employed. Frequencies and percentages were used to describe categorical data. The Pearson correlation co-efficient （r） and Spearman＇s rank co-efficient were used to measure the strength or degree of the relationship between variables and identify the significance of the correlation between two variables respectively. Results indicate that males in the sample （n = 619） are more likely to acknowledge self-perceived risk than females. This paper concludes that management strategies should be put in place in all universities in order to help the students stay HIV negative. Unless HIV and AIDS are institutionalised, the management of risk behaviour will prove difficult.展开更多
Catch crops that are cultivated for green manure play an important role in improving soil properties. A 3-year field experi- ment was conducted to investigate the effect of catch crop （pea, Pisum sativum L.） managem...Catch crops that are cultivated for green manure play an important role in improving soil properties. A 3-year field experi- ment was conducted to investigate the effect of catch crop （pea, Pisum sativum L.） management, i.e., incorporation of catch crop in October/November （autumn） and March （spring）, and without catch crop （control）, on soil organic carbon （SOC）, microbial biomass carbon （MBC） and the activities of carbon （C）-cycle enzymes, including cellulase （Cel）, β-glucosidase （Glu） and invertase （Inv）. Additionally, soil total nitrogen （TN） and pHKcl were investigated. The catch crop was cultivated from August to October each year during 2008-2010. Soil samples were collected from the field of spring barley （Hordeum vulgate L.） that had been grown after the catch crop. Soil samples for microbial activity determination were taken in March, May, June and August in 2009, 2010 and 2011, while SOC and TN contents as well as pHKc1 were determined in March and August. The chemical properties studied did not show significant changes as influenced by the experimental factors. The use of catch crop significantly increased the MBC content and the activities of C-cycle enzymes compared to the control. When the catch crop was incorporated in spring, a significantly higher MBC content was noted in March and May compared to autumn incorporation. Moreover, the spring incorporation of the catch crop significantly increased the Glu activity （except March）, while the activities of Cel and Inv as well as the rate of soil basal respiration were usually unaffected by the time of catch crop incorporation. Greater microbial biomass and higher enzyme activities in the catch crop-treated soil, compared to the control, indicated that the application of the catch crop as a green manure could be recommended as a promising technique to increase the biological activity of the soil. Since there was no significant effect or no consistent results were obtained related to the time of catch crop incorporation, both spring and autumn applications can be recommended as a management tool to improve the status of soil properties during the growth of a subsequent crop.展开更多
文摘目的分析评价儿童变应性鼻炎患者的症状和生活质量及两者的相关性,同时评估皮肤点刺试验(skin prick test,SPT)结果与症状、生活质量的相关性。方法分别用症状视觉模拟评分(visual analogue scale,VAS)和鼻结膜炎相关生活质量问卷(rhinoconjunctivitis quality of life questionnaire,RQLQ)评价儿童及成人变应性鼻炎患者的症状严重程度及生活质量,记录SPT结果,并进行统计学分析。结果①儿童与成人VAS各项症状间比较均有显著性差异(F=121.25,P<0.01;F=264.89,P<0.01),儿童患者评分最高的症状是鼻塞,而成人患者的首要症状是喷嚏。②儿童及成人RQLQ中生活质量最受影响的方面均为鼻部症状(3.04±5.80,P<0.01;2.72±1.68,P<0.01)。③VAS和RQLQ相关性分析提示,儿童及成人患者VAS鼻部总评分与RQLQ的总分均呈正相关,其中儿童患者难以入睡评分及因症状而觉得尴尬评分与鼻涕VAS评分呈正相关(r=0.230,P=0.043;r=0.325,P=0.004),夜间醒来次数评分与鼻痒、喷嚏VAS评分呈正相关(r=0.385,P=0.001;r=0.231,P=0.042);而成人患者睡眠方面评分、无耐心或烦躁、易怒评分均与鼻塞VAS评分呈正相关(P<0.01),此外喷嚏VAS评分也与部分情感呈正相关(P<0.01)。④SPT结果与两量表的各方面及总分均无显著相关。结论儿童与成人患者症状和生活质量存在差异;鼻涕、鼻痒可能是影响儿童患者生活质量的主要原因,而鼻塞、喷嚏对成人患者生活质量的影响更为显著;变应原级别与症状严重程度及生活质量无显著相关。
基金Supported by National Natural Science Foundation of China(31072155)Natural Science Foundation of Jiangsu Province(BK2010068)+1 种基金Fund for Independent Innovation of Agricultural Science in Jiangsu Province[CX(11)2060]Special Fund for Agroscientific Research in the Public Interest(201303041)~~
文摘[Objective] This study aimed to establish a method for quantitative detection of mRNA transcriptional level of SS2 adhesive related-factors of Streptococcus suis serotype 2 （SS2） by fluorescent quantitative PCR. []Vlethod] The gene fragments en- coding SS2 adhesive related-factors MRP, FBPS and CPS2J and a housekeeping gene aroA were amplified by reverse transcription PCR from the total RNA of SS2, cloned, and sequenced. The recombinant plasmids containing the target genes were constructed, and used as templates in Real-time PCR. [Result] Dynamic curves, stan- dard curves and melting curves of the adhesive related-factors and aroA were ob- tained by the optimized Real-time PCR system. The standard curves showed a good linear relationship between template copy number and circulation number, and the correlation coefficients （FF） of the standard curves were over 0.995. Also, these as- says were highly specific a^d there was single specific melting peak for every gene. Moreover, the assays were highly sensitive and had a detection limit of 1.0×102 copies in 1 μl of initial templates. Finally, it was highly repeatable and had a coeffi- cient of variation less than 2% for intra-assay. [Conclusion] This study will provide a way to reveal the adhesion mechanism of SS2 to different host cells at molecular level.
文摘This study explored HIV risk perception of university students. A descriptive study design amongst a convenience sample of registered students at the Nelson Mandela Metropolitan University （NMMU）, who gave voluntary informed consent to participate, and with access to the student portal was employed. Frequencies and percentages were used to describe categorical data. The Pearson correlation co-efficient （r） and Spearman＇s rank co-efficient were used to measure the strength or degree of the relationship between variables and identify the significance of the correlation between two variables respectively. Results indicate that males in the sample （n = 619） are more likely to acknowledge self-perceived risk than females. This paper concludes that management strategies should be put in place in all universities in order to help the students stay HIV negative. Unless HIV and AIDS are institutionalised, the management of risk behaviour will prove difficult.
文摘Catch crops that are cultivated for green manure play an important role in improving soil properties. A 3-year field experi- ment was conducted to investigate the effect of catch crop （pea, Pisum sativum L.） management, i.e., incorporation of catch crop in October/November （autumn） and March （spring）, and without catch crop （control）, on soil organic carbon （SOC）, microbial biomass carbon （MBC） and the activities of carbon （C）-cycle enzymes, including cellulase （Cel）, β-glucosidase （Glu） and invertase （Inv）. Additionally, soil total nitrogen （TN） and pHKcl were investigated. The catch crop was cultivated from August to October each year during 2008-2010. Soil samples were collected from the field of spring barley （Hordeum vulgate L.） that had been grown after the catch crop. Soil samples for microbial activity determination were taken in March, May, June and August in 2009, 2010 and 2011, while SOC and TN contents as well as pHKc1 were determined in March and August. The chemical properties studied did not show significant changes as influenced by the experimental factors. The use of catch crop significantly increased the MBC content and the activities of C-cycle enzymes compared to the control. When the catch crop was incorporated in spring, a significantly higher MBC content was noted in March and May compared to autumn incorporation. Moreover, the spring incorporation of the catch crop significantly increased the Glu activity （except March）, while the activities of Cel and Inv as well as the rate of soil basal respiration were usually unaffected by the time of catch crop incorporation. Greater microbial biomass and higher enzyme activities in the catch crop-treated soil, compared to the control, indicated that the application of the catch crop as a green manure could be recommended as a promising technique to increase the biological activity of the soil. Since there was no significant effect or no consistent results were obtained related to the time of catch crop incorporation, both spring and autumn applications can be recommended as a management tool to improve the status of soil properties during the growth of a subsequent crop.
