全文获取类型
收费全文 | 715篇 |
免费 | 5篇 |
国内免费 | 11篇 |
专业分类
儿科学 | 2篇 |
妇产科学 | 335篇 |
基础医学 | 97篇 |
临床医学 | 7篇 |
内科学 | 50篇 |
皮肤病学 | 3篇 |
神经病学 | 7篇 |
特种医学 | 1篇 |
外科学 | 72篇 |
综合类 | 43篇 |
预防医学 | 60篇 |
药学 | 36篇 |
中国医学 | 8篇 |
肿瘤学 | 10篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 21篇 |
2021年 | 34篇 |
2020年 | 18篇 |
2019年 | 16篇 |
2018年 | 12篇 |
2017年 | 20篇 |
2016年 | 15篇 |
2015年 | 34篇 |
2014年 | 55篇 |
2013年 | 64篇 |
2012年 | 47篇 |
2011年 | 49篇 |
2010年 | 58篇 |
2009年 | 48篇 |
2008年 | 39篇 |
2007年 | 35篇 |
2006年 | 33篇 |
2005年 | 20篇 |
2004年 | 20篇 |
2003年 | 7篇 |
2002年 | 14篇 |
2001年 | 5篇 |
2000年 | 9篇 |
1999年 | 7篇 |
1998年 | 4篇 |
1997年 | 8篇 |
1996年 | 6篇 |
1995年 | 2篇 |
1994年 | 7篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1982年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有731条查询结果,搜索用时 15 毫秒
41.
《Immunological investigations》2013,42(5):458-468
To investigate the impact of anti-nuclear antibodies (ANAs) on the outcome of in vitro fertilization-embryo transfer (IVF-ET), 66 (96 cycles) infertile women positive for anti-nuclear antibodies (ANA+ group), and 233(285 cycles) infertile women negative for ANAs (ANA? group) were enrolled. The clinical characteristics and IVF outcome were compared between the two groups. In the ANA+ group, the proportion of MII oocytes and two-pronuclear zygotes (2PN), cleavage rate, number of available embryos and proportion of available embryos, number of high-quality embryos and proportion of high-quality embryos were significantly lower than those in the ANA? group. In addition, the pregnancy rate and implantation rate in patients positive for ANA was markedly lower than the ANA? patients (28.1% vs 46.4%, 15% vs 25.7%, respectively). Thus, our findings suggest that the presence of ANAs significantly interfere with the oocyte and embryo development, as well as reduce implantation and pregnancy rate in patients undergoing IVF treatment. 相似文献
42.
目的 探讨胞质线粒体的氧化磷酸化(OXPHOS)活性或线粒体DNA复制在卵子成熟、受精和胚胎发育过程中的作用。方法 通过在小鼠体外成熟培养液中引入不同浓度的羰基氰4-(三氟甲氧基)苯腙 (FCCP, 10 nmol/L和100nmol/L)或2′,3′-双脱氧胞苷(ddC,10μmol/L和100μmol/L),抑制线粒体OXPHOS活性或线粒体DNA复制,统计分析各组卵子的体外生发泡破裂(GVBD)率、核成熟率、受精率及囊胚形成率,以分析线粒体功能抑制对卵子成熟、受精和胚胎发育的影响。 结果 线粒体OXPHOS活性和DNA复制功能在卵子和胚胎中所发挥的作用并不完全相同。FCCP抑制线粒体OXPHOS活性可显著降低卵子的核成熟率和囊胚形成率;但对卵子的GVBD的发生率和受精率无显著影响。而ddC抑制线粒体DNA复制不影响卵子的体外成熟和受精,但可显著抑制囊胚的形成。 结论 OXPHOS活性主要影响卵子成熟及胚胎发育;线粒体DNA复制则主要影响胚胎发育;而线粒体功能抑制不影响卵子的成熟启动和体外受精。 相似文献
43.
目的探讨控制超排卵(COH)中获卵数对体外受精一胚胎移植(IVF—ET)妊娠结局的影响,及为避免重度OHSS全胚冷冻的效果。方法接受常规IVF助孕治疗的不孕症患者358例(除外ICSI,Half—ICSI,Re—ICSI)。根据获卵数不同分为3组,其中获卵数1~10者122例(I组),获卵数11~20者183例(II组),获卵数〉20者53例(Ⅲ组);358例中发生OHSS48例全胚冷冻,其中I组无全胚冷冻,Ⅱ组全胚冷冻28例,Ⅲ组全胚冷冻20例。结果全胚冷冻组与新鲜移植组比较:年龄及优胚率无明显差异,着床率及临床妊娠率无明显差异;新鲜移植第Ⅲ组着床率及临床妊娠率低于全胚冷冻第Ⅲ组,差异有显著性。结论OHSS时全胚冷冻保证了妊娠结局,尤其对获卵数〉20的患者有利。 相似文献
44.
Hye Jin Chang Jung Ryeol Lee Byung Chul Jee Chang Suk Suh Seok Hyun Kim 《Journal of Korean medical science》2009,24(2):262-268
This study was performed to analyze retrospectively outcomes of stimulated in vitro fertilization (IVF) cycles where the gonadotropin-releasing hormone (GnRH) antagonist was omitted on ovulation triggering day. A total of 92 consecutive IVF cycles were included in 65 women who are undergoing ovarian stimulation with recombinant FSH. A GnRH antagonist, cetrorelix 0.25 mg/day, was started when leading follicle reached 14 mm in diameter until the day of hCG administration (Group A, 66 cycles) or until the day before hCG administration (Group B, 26 cycles). The duration of ovarian stimulation, total dose of gonadotropins, serum estradiol levels on hCG administration day, and the number of oocytes retrieved were not significantly different between the two groups. The total dose of GnRH antagonist was significantly lower in Group B compared to Group A (2.7±0.8 vs. 3.2±0.9 ampoules). There was no premature luteinization in the subjects. The proportion of mature oocytes (71.4% vs. 61.7%) and fertilization rate of mature (86.3±19.7% vs. 71.8±31.7%) was significantly higher in Group B. There were no significant differences in embryo quality and clinical pregnancy rates. Our results suggest that cessation of the GnRH antagonist on the day of hCG administration during a flexible multiple-dose protocol could reduce the total dose of GnRH antagonist without compromising IVF results. 相似文献
45.
46.
47.
卵泡液中VEGF水平对卵母细胞成熟及早期胚胎发育的影响 总被引:1,自引:0,他引:1
目的:探讨体外受精-胚胎移植(IVF-ET)和卵母细胞胞质内单精子注射(ICSI)周期中血管内皮生长因子(VEGF)水平与卵母细胞成熟及早期胚胎质量的关系。方法:采用酶联免疫吸附试验(ELISA)检测78例接受IVF和ICSI助孕治疗的患者采卵日卵泡液中VEGF的水平,实验室观察同一卵泡腔内对应的卵母细胞的成熟度及其受精后胚胎发育情况,并结合临床上患者的年龄、促排卵方案等情况,分析两者之间的关联。结果:①卵泡液中VEGF的水平与卵母细胞成熟度研究表明:中间型及成熟型卵母细胞与未成熟型比较,差异有显著性(P<0.05),而其它型之间差异没有显著性差异(P>0.05)。②卵泡液中VEGF的水平与早期胚胎发育研究表明:优质胚胎(Ⅰ、Ⅱ级)与非优质胚胎(Ⅲ、Ⅳ级)差异有显著性(P<0.05)。③卵母细胞成熟度处于中间型和成熟型组,年龄>35岁接受治疗的患者卵泡液中VEGF水平相比于年龄低于35岁的患者,差异有显著性(P<0.05)。结论:①卵泡液中VEGF浓度在一定范围内对卵母细胞成熟有促进作用,可作为评估卵母细胞质量、胚胎质量的有效指标之一。②在IVF和ICSI周期中,卵泡液中VEGF的水平可以作为筛选优质卵母细胞质量的参考指标,并可以作为指导及预测妊娠结局的有效指标之一,但是要注意患者年龄的因素。 相似文献
48.
Reduced Senescence and Retained Nuclear DNA Integrity in Human Spermatozoa Prepared by Density Gradient Centrifugation 总被引:1,自引:0,他引:1
Morrell JM Moffatt O Sakkas D Manicardi GC Bizzaro D Tomlinson M Nilsson H Holmes PV 《Journal of assisted reproduction and genetics》2004,21(6):217-222
PURPOSE: To investigate whether removal of extraneous cells and immotile spermatozoa from a sperm preparation by density gradient centrifugation could help to maintain normal spermatozoa in a viable state and retain their deoxyribonucleic acid integrity. METHODS: Sperm motility was assessed on a daily basis in aliquots of neat semen, extended semen, and spermatozoa prepared on a PureSperm density gradient. At the same time, aliquots of each sperm sample were preserved for TUNEL assay and nick translation. RESULTS: Spermatozoa prepared using density gradient centrifugation survived three times as long as spermatozoa in neat semen or in extended semen. Both deoxyribonucleic acid integrity and sperm motility were retained in the gradient preparations. CONCLUSIONS: Preparing spermatozoa by density gradient centrifugation is advantageous in prolonging sperm survival and maintaining deoxyribonucleic acid integrity, presumably by removing sources of reactive oxygen species. Stored spermatozoa could be used for a second attempt at fertilization if oocyte immaturity was suspected. 相似文献
49.
OBJECTIVE: To assess post-donation psychological status of a large sample of professionally recruited, paid anonymous donors and to determine whether there were any differences between those who were willing to donate again and those who were not. DESIGN: Cross-sectional survey. SETTING: Healthy donors who were recruited by two private groups. SUBJECT(S): One hundred fifteen donors who had completed at least one donation cycle at one of six IVF programs in a large Midwestern city. INTERVENTION(S): None. MAIN OUTCOME MEASURES: Self-report questionnaire assessing psychological symptoms, self-esteem, expectations, satisfaction, and attitudes toward donation. RESULT(S): Psychological symptomatology and self-esteem were in the normal range. Altruism and compensation were the two most frequently cited motivators for donation. Of the donors, 82% were moderately to very satisfied with the donation experience. First-time donors were significantly younger, reported more post-donation psychiatric symptoms, and had slightly lower self-esteem. Of the donors, 35% stated they would donate again; 37% would not, and 28% were undecided. Donors who were willing to donate again reported significantly less ambivalence about donation and significantly greater satisfaction with the medical aspects of donation. CONCLUSION(S): Approximately one third of donors are willing to donate more than once. These women report less ambivalence and greater satisfaction with the donation experience. 相似文献
50.
Garcia-Velasco JA Isaza V Caligara C Pellicer A Remohí J Simón C 《Fertility and sterility》2003,80(1):54-60
OBJECTIVE: To investigate the factors that may be related to pregnancy in oocyte recipients who shared oocytes from the same donor and showed discordant pregnancy outcome. DESIGN: Matched pair analysis. SETTING: IVF academic center. PATIENT(S): Five hundred forty-two oocyte donation cycles that shared oocytes from 197 donors with discordant outcome. INTERVENTION(S): Egg donation and embryo transfer. MAIN OUTCOME MEASURE(S): Pregnancy rate and implantation rate. RESULT(S): Three hundred sixty-five matched-paired discordant outcome oocyte recipients were analyzed. Pregnant and nonpregnant recipients were similar in terms of age, serum E(2) levels, endometrial thickness, indications for oocyte donation, and abnormal sperm parameters. No differences were found in the number of oocytes received per patient, fertilization rate, IVF/intracytoplasmic sperm injection (ICSI) distribution, embryo quality, or on embryo transfer difficulty. CONCLUSION(S): Discordant pregnancy outcome could not be explained by the different egg recipients and cycle factors studied. In addition to chance, other factors must be investigated that could explain discordant outcome in egg recipients sharing oocytes from single donors. 相似文献