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1.
Grapes are rich sources of potentially bioactive polyphenols. However, the phenolic content is variable depending on grape variety, and may be modified during vinification. In this study, we examined the chemical composition and biological activity of phenolic extracts prepared from several red wine grape varieties and their fermented byproduct of winemaking (pomace) on some of the virulence properties of Streptococcus mutans a well-known dental pathogen. Grape phenolic extracts were obtained from Vitis vinifera varieties Cabernet Franc and Pinot Noir and Vitis interspecific hybrid varieties Baco Noir and Noiret. The anthocyanins and flavan-3-ols content were highly variable depending on grape variety and type of extract (whole fruit vs fermented pomace). Nevertheless, all grape phenolic extracts remarkably inhibited glucosyltransferases B and C (70-85% inhibition) at concentrations as low as 62.5 microg/mL (P < 0.01). Furthermore, the glycolytic pH-drop by S. mutans cells was inhibited by the grape extracts without affecting the bacterial viability; an effect that can be attributed to partial inhibition of F-ATPase activity (30-65% inhibition at 125 microg/mL; P < 0.01). The biological activity of fermented pomace was either as effective as or significantly better than whole fruit grape extracts. The results showed that grape phenolic extracts, especially from pomace, are highly effective against specific virulence traits of S. mutans despite major differences in their phenolic content.  相似文献   
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In this study, we examined the effects of reconstructed oocyte–granulosa cell complexes (OGCs) on the development of porcine oocytes derived from early antral follicles (EAFs; 0.5–0.7 mm in diameter). When denuded oocytes were cocultured with granulosa cells derived from other EAFs, the oocytes and granulosa cells aggregated to form OGCs after 2 days of culture. After 14 days of culture, we compared cell number, oocyte diameter, and oocyte chromatin configuration in unmanipulated (natural) OGCs, reconstructed OGCs, and OGCs collected from antral follicles (AFs, 3.0–6.0 mm in diameter). The diameters of oocytes from reconstructed OGCs grown in vitro were not different from those of oocytes from natural OGCs, although they were significantly smaller than those of oocytes from antral follicle (AF) OGCs. Oocyte chromatin configuration did not differ among the 3 OGC groups, but the oocyte nuclear maturation rate was lower in the reconstructed OGCs and higher in the AF OGCs. However, when the in vitro culture period for the reconstructed OGCs was extended by 2 days, the nuclear maturation rate of oocytes from reconstructed OGCs was similar to that of oocytes from natural OGCs. In addition, blastocysts were successfully obtained from oocytes from reconstructed OGCs. In conclusion, we established an innovative culture method that allows oocytes and granulosa cells from EAFs to reaggregate as reconstructed OGCs, which yield oocytes with the ability to develop to the blastocyst stage.  相似文献   
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Effective preselection of sex has been accomplished in several species of livestock and also in humans using the flow cytometric sperm sorting method. A guaranteed high sorting accuracy is a key prerequisite for the widespread use of sperm sexing. The standard validation method is flow cytometric remeasurement of the DNA content of the sexed sperm. Since this method relies on the same instrument that produced the original sperm separation, it is not truly independent. Therefore, to be able to specifically produce either male or female offspring in the dog, we developed a method of direct visualization of sex chromosomes in a single sperm using fluorescence in situ hybridization (FISH) as a validation method. Denaturation of canine spermatozoa by immersion in 1 M NaOH for 4 min yielded consistent hybridization results with over 97% hybridization efficiency and a good preservation of sperm morphology. There was no significant difference between the theoretical ratio (50:50) and the observed ratio of X- and Y-chromosome-bearing spermatozoa in any of the three dogs. In addition, the mean purities of flow-sorted sex chromosomes in spermatozoa of the three dogs were 90.8% for the X chromosome fraction and 89.6% for the Y chromosome fraction. This sorting was evaluated by using the dual color FISH protocol. Therefore, our results demonstrated that the FISH protocol worked reliably for both unsorted and sexed sperm samples.  相似文献   
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The objectives of the present study were to investigate the bacteria accompanying hydrosalpinx of the buffalo cow and investigate the correlation between bacterial infection of the uterus and hydrosalpinx. Buffalo cows’ reproductive tracts were collected from Mosul abattoir. A total 385 uterine samples were examined of which 25 were having hydrosalpinx. Swabs for bacteriology, fluid for cytology and biopsies for histopathology were collected from the hydrosalpinx and the uterus from each samples included in this study. Results of this study indicated high prevalence of hydrosalpinx (6.5%) including unilateral (n = 19; 76%) and bilateral (n = 6; 24%) hydrosalpinx. Although 16 samples (64%) of the hydrosalpinx samples had no bacterial growth, the most prevalent bacteria recovered from hydrosalpinx were Corynebacterium hemolyticum and Actinomyces bovis, 42.8% and 28.6%, respectively. The most prevalent bacteria in the uterus were Archanobacterium pyogenes (18.5%), Staphylococcus aureus (14.8%), and Listeria monocytogenes (11.0%). Higher rates of leukocytes infiltration (p < 0.01) were observed in the uterine discharge than hydrosalpinx. A significant (p < 0.01) increase in lymphocytes was found in uterine discharge. Microscopic examination of the hydrosalpinx showed mucosal atrophy and dilatation of oviductal lumen without any signs of inflammation. It could be concluded that there is no correlation between bacteria isolated from uterus and hydrosalpinx. No association was found between bacteriological cultures and hydrosalpinx. Inflammation of the uterine tissue could be extended to utero‐tubal junction producing local inflammation resulting in fibrosis and tubal obstruction. The obstruction in the lumen of the oviducts resulted in accumulation of fluid.  相似文献   
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针对扩招后我国普通高等农业院校存在的普适性问题,介绍并分析了英国哈珀亚当斯农学院的办学宗旨,以及在办学理念、人才培养方案、教学方式、教学管理、质量监控等方面的特点,提出国内高等农业教育发展的5大对策:服务新农村建设,明确人才培养目标;改革传统教学模式,加强实践教学,重视能力培养;实行学分制与导师制,加强学生创新能力与个性化培养;理顺教学管理关系,建立质量监控评价体系;以学生为中心,完善支持服务体系,培养优良品格。  相似文献   
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针对机动车车型识别中声信号非平稳且易受噪声干扰的问题,提出了一种有效的声信号特征提取方法。利用小波包分析技术对声信号的能量分布进行研究,以德比契斯(Daubechies)小波为基函数对目标声信号进行小波包变换。基于获取的不同频带能量分布状态给出了机动车车型的特征判据,并对该判据的有效性给予了分析。试验结果表明基于小波包分析的机动车声信号特征提取方法是有效的。  相似文献   
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The objectives of this study were to determine the non‐specific aerobic and anaerobic bacterial causes of endometritis causing repeat breeding of cycling Iraqi buffalo cows at Nineveh province, validate diagnostic criteria for endometritis and to evaluate the treatment efficiency of using systemic or intra‐uterine infusion of antibiotics for the treatment of endometritis. Data were collected from 60 buffalo cows with history of repeat breeding in different herds. All buffaloes were subjected to detailed clinical examination including external inspection, vaginoscopy and transrectal palpation of the cervix, uterus and ovaries. Swabs for bacteriology and biopsies for histopathology were collected from the uterine lumen from each cow. Character, odour and estimation of polymorphonuclear cells (PMN) of the vaginal mucus were scored. Blood samples were collected from cows for creatine kinase (CK) and aspartate aminotransferase (AST) measurement. Treatment conducted using oxytetracycline with tylosin in local intrauterine infusion or systemically with hormonal treatment. The most pre‐disposing factor for uterine infection was retained placenta (13.3%). The most prevalent bacteria in uterine lumen were E. coli (23%), Archanobacterium pyogenes (13%) and Staphylococcus aureus (10%) were mostly isolated from buffaloes with repeat breeding. Vaginal mucus character score was associated with the bacterial growth density score. The difference in PMN was highly significant (p < 0.01) in animals with repeat breeding than control groups. In addition, PMNs was significantly (p < 0.01) correlated r = 0.894 with the character of vaginal discharge. High level of PMNs observed in buffaloes infected with A. pyogenes. Buffalo cows with endometritis had higher CK (321.47 ± 39.06 vs 162.01 ± 16.41 U/l) and AST (133.93 ± 12.43 vs 97.01 ± 6.86 U/l) activities (p < 0.05) than control‐heifers, but no significant difference was observed between buffalo cows with endometritis in CK (321.47 ± 39.06 vs 208.33 ± 5.84) and AST (133.93 ± 12.43 vs 156.17 ± 9.65) activities than control‐pluriparious. It could be concluded that A. pyogenes was the only non‐specific uterine pathogen directly associated with severe endometrial lesions. Vaginoscopy examination combined with palpation of uterus increase the accuracy of diagnosing endometritis and cytogenic examination of uterine discharge is more reliable method of establishing the presence or absence of uterine inflammation in buffalo cows. Animals with repeat breeding (endometritis) showed clinical cure and improved pregnancy in all treatment groups with no significant difference. The use of oestradiol in repeat breeder cases has no effect in improving neither clinical cure rate nor pregnancy rate.  相似文献   
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The objectives of the present study were to determine the relationship between bacteriological findings, clinical signs and histopathological changes in postpartum metritis. Evaluation of the treatment efficiency of using systemic or intra‐uterine infusion of antibiotics with some hormonal preparations for the treatment of postpartum metritis. Data were collected from 50 buffalo cows with history of calving of more than 1 month. All buffaloes were subjected to detailed clinical examination including external inspection, vaginoscopy and transrectal palpation of the cervix, uterus and ovaries. Swabs for bacteriology and biopsies for histopathology were collected from uterine lumen from each buffalo included in the present study. Bacteria identified using API systems following aerobic and anaerobic cultures. Vaginal mucus scored for character, odour and estimation of polymorphonuclear cells (PMNs). Treatment conducted using oxytetracycline in local intrauterine infusion or systemically with hormonal treatment including prostaglandinF2α (PGF2α) and oestradiol benzoate. Results revealed that the most predisposing factor for postpartum uterine infection was retained placenta and toxic puerperal metritis. The most prevalent bacteria in uterine lumen were Escherichia coli, Archanobacterium pyogenes, Bacteroides fragilis and Fusobacterium necrophorum the most prevalent bacteria in buffaloes with postpartum metritis. A. pyogenes and F. necrophorum were an important pathogens causing severe uterine inflammation as found in histopathological examinations. Buffaloes with postpartum metritis showed good clinical cure when oxytetracycline injected systemically with PGF2α. Intrauterine infusion of oxytetracycline had no advantage for the treatment of uterine infection in buffalo cows with postpartum metritis. PGF2α improved clinical cure of buffaloes with postpartum metritis.  相似文献   
10.
本文讨论了作物水模型常规多元线性回归以及稳健回归的建立方法.基于内蒙古河套灌区曙光试验站玉米非充分灌溉试验资料,利用MATLAB中提供的稳健回归方法建立了Minhas型作物水模型,并与常规的多元线性回归方法进行了比较.结果表明采用稳健回归的方法比常规的多元线性回归可在一定程度上提高作物水模型的回归效果.  相似文献   
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