全文获取类型
收费全文 | 2053篇 |
免费 | 106篇 |
国内免费 | 89篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 11篇 |
妇产科学 | 285篇 |
基础医学 | 223篇 |
口腔科学 | 7篇 |
临床医学 | 107篇 |
内科学 | 188篇 |
皮肤病学 | 17篇 |
神经病学 | 229篇 |
特种医学 | 19篇 |
外科学 | 114篇 |
综合类 | 334篇 |
预防医学 | 158篇 |
眼科学 | 11篇 |
药学 | 327篇 |
1篇 | |
中国医学 | 129篇 |
肿瘤学 | 85篇 |
出版年
2024年 | 3篇 |
2023年 | 12篇 |
2022年 | 20篇 |
2021年 | 35篇 |
2020年 | 45篇 |
2019年 | 30篇 |
2018年 | 42篇 |
2017年 | 51篇 |
2016年 | 51篇 |
2015年 | 47篇 |
2014年 | 94篇 |
2013年 | 138篇 |
2012年 | 80篇 |
2011年 | 114篇 |
2010年 | 81篇 |
2009年 | 93篇 |
2008年 | 86篇 |
2007年 | 92篇 |
2006年 | 118篇 |
2005年 | 107篇 |
2004年 | 76篇 |
2003年 | 102篇 |
2002年 | 82篇 |
2001年 | 55篇 |
2000年 | 35篇 |
1999年 | 48篇 |
1998年 | 44篇 |
1997年 | 43篇 |
1996年 | 34篇 |
1995年 | 32篇 |
1994年 | 27篇 |
1993年 | 27篇 |
1992年 | 21篇 |
1991年 | 25篇 |
1990年 | 25篇 |
1989年 | 17篇 |
1988年 | 17篇 |
1987年 | 21篇 |
1986年 | 15篇 |
1985年 | 26篇 |
1984年 | 26篇 |
1983年 | 18篇 |
1982年 | 19篇 |
1981年 | 15篇 |
1980年 | 23篇 |
1979年 | 7篇 |
1978年 | 12篇 |
1977年 | 4篇 |
1976年 | 7篇 |
1975年 | 4篇 |
排序方式: 共有2248条查询结果,搜索用时 15 毫秒
81.
目的 探讨雌二醇(E2)联合孕激素(P4)对microRNA-15a (miR-15a)表达的影响。方法 采集手术中切除的卵巢癌组织标本进行细胞培养,分3个处理组:E2组,P4组和雌二醇联合孕激素(E2+P4)组。激素处理后,MTT法检测细胞存活率;流式细胞技术检测细胞凋亡与细胞周期;qRT-PCR法检测Bcl-2,Bax和miR-15a的相对表达量。结果 高浓度(浓度均为10-4 mol·L-1)的E2,P4,E2+P4能够降低卵巢癌细胞的存活率,并表现为时间依赖性;低浓度(≤ 10-8 mol·L-1) E2能够提高卵巢癌细胞的存活率。与对照组相比,高浓度E2,P4和E2+P4能够增加卵巢癌细胞的凋亡率(P<0.001),并且E2+P4的作用最明显;低浓度E2能够抑制肿瘤细胞的凋亡(P<0.001)。E2,P4和E2+P4对细胞周期的影响没有统计学差异。高浓度的E2,P4和E2+P4能够下调Bcl-2的表达(P<0.05或P<0.001),上调Bax的表达(P<0.001);但是低浓度E2作用却相反。高浓度的E2+P4能够促进miR-15a的表达(P<0.001)。结论 高浓度的E2,P4和E2+P4能够降低细胞的存活率促进细胞凋亡,下调Bcl-2的表达,上调Bax的表达;低浓度E2的作用则相反;高浓度的E2+P4能够促进miR-15a的表达。 相似文献
82.
Background:Polycystic ovarian syndrome (PCOS) is an endocrine disorder syndrome with reproductive dysfunction and abnormal glucose metabolism. Persistent non-ovulation, excessive androgens and insulin resistance are important features and they are the most common causes of menstrual disorders in women during childbearing years. At present, the cause of PCOS is not clinically clear. Current studies suggest that it may be due to the interaction of certain genetic genes with environmental factors. It is an important cause of infertility or early miscarriage with the characteristics of various causes and complex clinical manifestations. At present, for the treatment of PCOS patients, clinical treatment mainly includes hypoglycemia, insulin and menstrual regulation and other symptomatic and supportive treatment. Drospirone ethinyl estradiol and ethinyl estradiol cyproterone are 2 of the most commonly used drugs in clinical treatment of PCOS, but there is lack of the evidence of evidence-based medicine. Therefore, this study systematically evaluates the therapeutic effect and safety of PCOS patients with 2 short-acting oral contraceptives, drospirone ethinyl estradiol and ethinyl estradiol cyproterone, which provides the guidance for clinically selecting the appropriate drug to treat PCOS.Methods:Searching CNKI, WanFang Data, VIP, SinoMed, PubMed, EMbase, Web of Science, and The Cochrane Library database by computer, collecting the randomized controlled studies of DEE and EEC in the treatment of PCOS. The retrieval time limit is from the establishment of each database to July 1, 2020. In addition, tracing the references incorporated into the literature to supplement to the relevant literature. Using the retrieval method by combining the free words and the subject words, and the individual search of different databases is carried out. Meta-analysis is performed using RevMan 5.3 software after 2 researchers independently screens the literature, extracts the data, and evaluates the bias risk included in the study.Results:This study will systematically evaluate the DEE and EEC in the treatment of PCOS by collecting the required evidence to understand the effects of the 2 drugs on hypersotrophicemia, insulin resistance, lipid metabolism, and the safety during drug use in patients of this class, and the results will be published in highly influential academic journals.Conclusion:The results of this study will provide theoretical basis for the drug treatment of polycystic ovarian syndrome and provide help in the decision-making of clinical treatment of the disease.Ethics and dissemination:In this study, meta-analysis was used to conduct a second study on the published literature. Therefore, this type of systematic review research does not need to be approved by ethics.OSF Registration DOI:10.17605/OSF.IO/8GW9M. 相似文献
83.
Wayne G. Brake 《The European journal of neuroscience》2014,39(2):257-265
Estrogen has been shown to enhance the effects of antipsychotics in humans. To investigate the mechanisms of how this may occur, the current study examined estradiol's effects on dopaminergic transmission and behavior in amphetamine‐sensitized and non‐sensitized female rats. Sixty‐four ovariectomized female Sprague–Dawley rats were used for this study. Half of the rats were sensitized to four once‐daily injections of 1 mg/kg amphetamine and the other half served as controls. Rats received chronic administration of either low‐dose haloperidol (0.25 mg/kg/day) or saline vehicle via osmotic minipumps implanted subcutaneously. The groups were further subdivided with respect to estradiol treatment: low chronic estrogen (subcutaneous estradiol implant, 0.36 mg/pellet: 90‐day release, plus an additional oil vehicle injection every second day) and high pulsatile estrogen (subcutaneous estradiol implant plus an additional 10 μg/kg estradiol injection every second day). Motor activity was assessed at day 2 and day 12 during haloperidol treatment, while nucleus accumbens dopamine availability was assessed via microdialysis 10 days into antipsychotic treatment. Haloperidol treatment along with high, but not low, estradiol replacement was effective in reducing amphetamine‐induced locomotor activity in sensitized rats. High estradiol treatment also augmented the effects of chronic haloperidol in reducing dopaminergic release in sensitized rats. These data suggest that estradiol levels affect both the behavioral and the dopamine responses to chronic antipsychotic treatment. 相似文献
84.
85.
目的评价17-β雌二醇用于辅助生殖患者宫腔粘连术后促子宫内膜修复的效果及对生育结局的影响。方法 429例拟行体外受精-胚胎移植(IVF-ET)患者,因宫腔粘连经宫腔镜下行宫腔粘连分离术和放置宫内节育器术,215例术后应用17-β雌二醇+地屈孕酮行周期治疗(雌二醇2mg bid)2周期(实验组),214例不行周期治疗(对照组)。所有病例定期随诊,治疗结束后再行宫腔镜检查探查宫腔情况并取出宫内节育器,再行胚胎移植,随访治疗疗效及妊娠结局。结果实验组的宫腔镜治疗治愈率明显较对照组高,X2=-3.16,p=0.002,实验组术后胚胎移植临床妊娠率也明显较对照组高X2=-2.75,p=0.006。结论宫腔粘连术后采用17-β雌二醇周期治疗,不但有利于宫腔形态的恢复及内膜的修复,而且可以提高内膜的容受性,明显改善妊娠结局。 相似文献
86.
Xiuhua Liao Zhou Li Xiyuan Dong Hanwang Zhang 《International journal of clinical and experimental pathology》2014,7(10):6992-6997
Endometrial preparation with exogenous estrogen is a common practice in frozen-thawed embryo transfer (FET) cycles. The objective of this study was to compare the clinical outcomes of two endometrial preparation groups, oral estradiol valerate tablets (OEV) group versus vaginal estradiol (VE) tablets group, in inadequate endometrium patients. This retrospective, single-center, cohort study of patients undergoing FET treatment between Jan. 2012 and Jun. 2013, at an academic IVF center, included 247 patients (cycles) with endometrial thickness < 8 mm on day 13 of the hormone replacement cycle: OEV group included 69 patients (cycles) who received continuous OEV from day 1 onwards up to the day of progesterone supplement, while VE group included 178 patients (cycles) who taken OEV from day 1 to day 12, and used VE tablets from day 13 till the day of progesterone supplement. Patients in VE group required more days and higher dosage of estradiol, but had thinner endometrium on the day of transfer. However, the increase of endometrial thickness was more, when compared to OEV-treated patients. The implantation rate and pregnancy rate were, though not significantly, higher in VE group. Conclusions: Longer time of administration and higher dosage of estradiol usage did not have adverse effects on the clinical pregnancy rate. VE tablets may promote endometrial development and pregnancy success in FET cycles could not verify. Further study is needed to confirm the vaginal estradiol action on frozen-thawed embryo transfer cycles. 相似文献
87.
Martin J. J. Ronis Horacio Gomez-Acevedo Kartik Shankar Leah Hennings Neha Sharma Michael L. Blackburn Isabelle Miousse Harry Dawson Celine Chen Kelly E. Mercer Thomas M. Badger 《Nutrients》2022,14(5)
Soy infant formula which is fed to over half a million infants per year contains isoflavones such as genistein, which have been shown to be estrogenic at high concentrations. The developing testis is sensitive to estrogens, raising concern that the use of soy formulas may result in male reproductive toxicity. In the current study, male White-Dutch Landrace piglets received either sow milk (Sow), or were provided milk formula (Milk), soy formula (Soy), milk formula supplemented with 17-beta-estradiol (2 mg/kg/d) (M + E2) or supplemented with genistein (84 mg/L of diet; (M + G) from postnatal day 2 until day 21. E2 treatment reduced testis weight (p < 0.05) as percentage of body weight, significantly suppressed serum androgen concentrations, increased tubule area, Germ cell and Sertoli cell numbers (p < 0.05) relative to those of Sow or Milk groups. Soy formula had no such effects relative to Sow or Milk groups. mRNAseq revealed 103 differentially expressed genes in the M + E2 group compared to the Milk group related to endocrine/metabolic disorders. However, little overlap was observed between the other treatment groups. These data suggest soy formula is not estrogenic in the male neonatal piglet and that soy formula does not significantly alter male reproductive development. 相似文献
88.
磷脂酰肌醇3激酶抑制剂对17β-雌二醇作用下Ishikawa、HEC-1A细胞增殖和凋亡的影响 总被引:1,自引:0,他引:1
目的:观察磷脂酰肌醇3激酶(PI3K)抑制剂LY294002 对17β-雌二醇(E2)作用下子宫内膜癌细胞增殖、凋亡和细胞周期的影响,初步探讨阻断PI3K/Akt通路治疗子宫内膜癌的可能性. 方法:应用MTT法(10-10 mol/L、10-8 mol/L、10-6 mol/L、10-4 mol/L的E2或10-6 mol/L E2及0.1 μmol/L、1 μmol/L、10 μmol/L、50 μmol/L的LY294002)、流式细胞技术(0 mol/L、10-8 mol/L、10-6 mol/L E2或10-6 mol/L E2及0 μmol/L、1 μmol/L、50 μmol/L LY294002)观察LY294002对E2作用下子宫内膜癌细胞Ishikawa、HEC-1A增殖、凋亡和细胞周期的影响.结果:随着E2浓度的增加,Ishikawa细胞A(570 nm)值逐渐升高并呈时间依赖性(F=3.915,P=0.043),G0-G1期比例下降(F=50.926,P≤0.001),S期比例升高(F=17.836,P=0.001);而HEC-1A细胞周期各期比例无变化(P>0.05).随着 LY294002浓度的增加,2种细胞A(570 nm)值逐渐下降并呈现时间依赖性(F=10.398,P=0.001;F=5.542,P=0.043),而且G0-G1期比例(F=32.024, P≤0.005;F=14.725,P≤0.017)升高,S期(F=30.132, P≤0.001;F=24.72,P≤0.01)比例下降.50 μmol/L和100 μmol/L LY294002作用2种细胞48 h后,凋亡细胞百分比均增加(P<0.001).结论:LY294002可以抑制E2对子宫内膜癌细胞的增殖,促使其发生凋亡,抑制细胞周期进展,使细胞周期停滞在G1期.PI3K/Akt信号传导通路可作为治疗子宫内膜癌的新靶点. 相似文献
89.
90.
目的:探讨8-溴-环磷酸腺苷(8-Br-cAMP)和血小板衍生生长因子(PDGF)对多囊卵巢综合征(PCOS)患者离体卵巢黄素化颗粒细胞雌二醇(E2)生成的影响.方法:收集体外授精-胚胎移植(IVF-ET)时PCOS患者(n=6)和正常对照(n=8)的黄素化颗粒细胞进行体外原代培养,在其培养的不同时间(0 h、48 h、120 h)以睾酮(10-7mol/L)作为底物,分别添加8-Br-cAMP(2 mmol/L)和(或)PDGF(10μg/L)于无血清培养液(TCM199)中,共培养3h后收集培养上清、细胞.用放射免疫法测定颗粒细胞分泌E2量;用考马斯亮蓝G250/BSA测颗粒细胞蛋白含量,以校正E2含量.结果:与对照组比较,8-Br-cAMP和PDGF在0 h、48 h和120 h均显著刺激PCOS组颗粒细胞分泌E2(P<0.05);8-Br-cAMP和PDGF联合作用在48 h、120 h显著刺激PCOS组颗粒细胞分泌E2(P<0.05).结论:8-Br-cAMP和PDGF均可加速PCOS患者卵巢颗粒细胞内雄激素向雌激素的转化;8-Br-cAMP和PDGF对颗粒细胞芳香化酶活性的调节作用是一致的. 相似文献