全文获取类型
收费全文 | 972篇 |
免费 | 74篇 |
出版年
2022年 | 12篇 |
2021年 | 24篇 |
2020年 | 12篇 |
2019年 | 21篇 |
2018年 | 19篇 |
2017年 | 12篇 |
2016年 | 25篇 |
2015年 | 41篇 |
2014年 | 41篇 |
2013年 | 70篇 |
2012年 | 80篇 |
2011年 | 59篇 |
2010年 | 31篇 |
2009年 | 32篇 |
2008年 | 48篇 |
2007年 | 55篇 |
2006年 | 35篇 |
2005年 | 31篇 |
2004年 | 39篇 |
2003年 | 36篇 |
2002年 | 35篇 |
2001年 | 16篇 |
2000年 | 16篇 |
1999年 | 19篇 |
1998年 | 10篇 |
1997年 | 9篇 |
1996年 | 8篇 |
1992年 | 8篇 |
1991年 | 10篇 |
1990年 | 8篇 |
1989年 | 16篇 |
1988年 | 8篇 |
1987年 | 6篇 |
1986年 | 5篇 |
1985年 | 9篇 |
1984年 | 7篇 |
1983年 | 12篇 |
1982年 | 9篇 |
1981年 | 8篇 |
1980年 | 7篇 |
1979年 | 17篇 |
1978年 | 6篇 |
1977年 | 5篇 |
1976年 | 8篇 |
1975年 | 5篇 |
1974年 | 6篇 |
1973年 | 12篇 |
1972年 | 5篇 |
1971年 | 6篇 |
1970年 | 5篇 |
排序方式: 共有1046条查询结果,搜索用时 15 毫秒
961.
P. Sowmya V. Nishitha Naik V. Sivaprasad 《Archives Of Phytopathology And Plant Protection》2013,46(19-20):1022-1038
AbstractThe study reports the characterization of 10 isolates of mulberry black root rot causing fungus, Botryodiplodia theobromae obtained from the infected gardens of Karnataka, Andhra Pradesh and Tamil Nadu. The analysis based on cultural, morphological, pathogenicity and molecular markers (RAPD and SSRs) revealed significant variations among the isolates. Based on the disease reaction on susceptible V-1 variety, isolates were grouped as pathogenic (60%), moderate pathogenic (20%) and non-pathogenic (20%). Among all isolates, RAPDs revealed higher marker polymorphism however, based on Shannon’s Information Index (I) SSRs were more informative (0.781) compared to the former (0.444). Stepwise Multiple Regression Analysis (MRA) indicated a total of 5, 5 and 3 molecular markers were found to correlate with disease symptoms. Screening of germplasm using multiple strains of virulent isolates will enhance possibilities of locating diverse resistant genes. Pyramiding of these genes will aid in development of mulberry variety with durable resistance and sustainable sericulture. 相似文献
962.
963.
Kitaw Demissie George G Rhoads John C Smulian Bijal A Balasubramanian Kishor Gandhi K S Joseph Michael Kramer 《BMJ (Clinical research ed.)》2004,329(7456):24-29
Objective To compare the risk of neonatal and infant adverse outcomes between vacuum and forceps assisted deliveries.Design Population based study.Setting US linked natality and mortality birth cohort file and the New Jersey linked natality, mortality, and hospital discharge summary birth cohort file.Participants Singleton live births in the United States (n = 11 639 388) and New Jersey (n = 375 351).Main outcome measures Neonatal morbidity and mortality.Results Neonatal mortality was comparable between vacuum and forceps deliveries in US births (odds ratio 0.94, 95% confidence interval 0.79 to 1.12). Vacuum delivery was associated with a lower risk of birth injuries (0.69, 0.66 to 0.72), neonatal seizures (0.78, 0.68 to 0.90), and need for assisted ventilation (< 30 minutes 0.94, 0.92 to 0.97; ≥ 30 minutes 0.92, 0.88 to 0.98). Among births in New Jersey, vacuum extraction was more likely than forceps to be complicated by postpartum haemorrhage (1.22, 1.07 to 1.39) and shoulder dystocia (2.00, 1.62 to 2.48). The risks of intracranial haemorrhage, difficulty with feeding, and retinal haemorrhage were comparable between both modes of delivery. The sequential use of vacuum and forceps was associated with an increased risk of need for mechanical ventilation in the infant and third and fourth degree perineal tears.Conclusion Although vacuum extraction does have risks, it remains a safe alternative to forceps delivery. 相似文献
964.
965.
966.
967.
968.
969.
970.
The effect of methylglyoxal on protein -SH and -NH2 groups in cytosolic and membranous fractions of epithelial cells lining the gastrointestinal tract of rat was investigated, using isolated villus and crypt cells (enterocytes) and colonocytes. It was found that 11-12% cytosolic protein -SH and 14-17% membrane protein -SH groups were lost when villus and crypt cells were treated with 2 mM methylglyoxal. In colonocytes, the corresponding loss in protein -SH groups was 46 and 30% under the same treatment. Similarly, 27-37% protein -NH2 group in the cytosolic fraction and 18-19% protein -NH2 group in membranous fractions of the enterocytes were lost by 2 mM methylglyoxal treatment. In colonocytes, the loss of protein -NH2 group was 30 and 15% in cytosolic and membranous fractions, respectively, under the same treatment. Effect of methylglyoxal on activity of various brush border enzymes such as alkaline phosphatase, gamma-glutamyl transpeptidase, leucine aminopeptidase, Mg2(+)-ATPase, sucrase and lactase was also studied. Alkaline phosphatase and gamma-glutamyl transpeptidase activities were inhibited to the extent of 30 and 15% respectively. There was no significant change in the activities of other enzymes after treating the brush border vesicles with 2 mM methylglyoxal. These findings show that methylglyoxal can cause loss of protein thiol and amino groups and enzyme activity in mucosal cells of rat gastrointestinal tract and the effect is more pronounced in colonocytes, which are in constant contact with bacterial metabolites. 相似文献