首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   59685篇
  免费   3942篇
  国内免费   1122篇
耳鼻咽喉   299篇
儿科学   1141篇
妇产科学   5426篇
基础医学   4997篇
口腔科学   862篇
临床医学   6301篇
内科学   7883篇
皮肤病学   489篇
神经病学   2311篇
特种医学   1823篇
外国民族医学   9篇
外科学   4519篇
综合类   9112篇
现状与发展   1篇
预防医学   9147篇
眼科学   328篇
药学   6209篇
  108篇
中国医学   1904篇
肿瘤学   1880篇
  2024年   71篇
  2023年   781篇
  2022年   1414篇
  2021年   2411篇
  2020年   2289篇
  2019年   1969篇
  2018年   1939篇
  2017年   1947篇
  2016年   2114篇
  2015年   1970篇
  2014年   4132篇
  2013年   4258篇
  2012年   3654篇
  2011年   3974篇
  2010年   3024篇
  2009年   2915篇
  2008年   2754篇
  2007年   2859篇
  2006年   2443篇
  2005年   2130篇
  2004年   1848篇
  2003年   1499篇
  2002年   1303篇
  2001年   1105篇
  2000年   1031篇
  1999年   877篇
  1998年   739篇
  1997年   735篇
  1996年   660篇
  1995年   584篇
  1994年   569篇
  1993年   433篇
  1992年   444篇
  1991年   407篇
  1990年   331篇
  1989年   325篇
  1988年   287篇
  1987年   234篇
  1986年   209篇
  1985年   296篇
  1984年   246篇
  1983年   157篇
  1982年   212篇
  1981年   176篇
  1980年   158篇
  1979年   140篇
  1978年   118篇
  1977年   102篇
  1976年   94篇
  1975年   102篇
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
61.

Background

Herbal medicine has been widely utilized by pregnant women despite the limited available evidence regarding the safety and efficacy of that practice. The current available studies, from different countries, estimated that the use of herbal medicine during pregnancy range from 7% up to 96%. The aim of this study is to determine the prevalence, attitude, source of information, and reasoning behind the use of herbal medicine among pregnant women in Saudia Arabia.

Methods

A cross-sectional study conducted using a convenience sample including pregnant women who visited the obstetric clinics at King Abdulaziz Medical City in Riyadh, Saudi Arabia. A survey was administered in order to evaluate the prevalence and perception toward herbal medicine use among pregnant women in Saudi Arabia.

Results

A total of 297 pregnant women completed the survey. The results showed that 56% of the respondents have used some type of herbal medicine during their pregnancy. Olive oil was utilized in 26% of the respondents followed by cumin 20% and garlic 15%. In addition, 37% of the respondents used herbal medicine by their own initiative, while 33% and 12% used herbal medicine based on recommendations from their families and friends, respectively. Furthermore, 19% of the respondents reported a positive attitude toward herbal medicine use during pregnancy. In addition, the percentage of women with positive attitude was marginally higher among respondents with lower educational level.

Conclusion

The prevalence of using herbal medicine is considerably high among pregnant women in Saudi Arabia. Unfortunately, the majority of the users relied on informal sources to use herbal medicine during pregnancy.  相似文献   
62.
The purpose of this study was to elucidate the involvement of Mate1 in the tubular secretion of trimethoprim and saturation of Mate1-mediated efflux to address the mechanisms underlying the pharmacokinetic drug interactions with trimethoprim. Trimethoprim is a more potent inhibitor of MATE2-K than MATE1 with Ki values (μM) of 0.030–0.28 and 2.4–5.9, respectively. Trimethoprim is a substrate of human MATE1 and MATE2-K with Km values of 2.3 ± 0.9 and 0.018 ± 0.004 μM, and mouse Mate1, but not human OCT2, mouse Oct1 and Oct2. Pyrimethamine significantly reduced the renal clearance (CLR) of trimethoprim (mL/min/kg) from 40.0 ± 5.1 to 20.1 ± 3.7 (p < 0.05). Trimethoprim was given to mice at three infusion rates (150, 500, and 1500 nmol/min/kg). Together with an increase in the plasma concentrations of trimethoprim, the CLR (mL/min/kg) of trimethoprim decreased to 25.9 ± 3.2, 13.5 ± 5.7, and 8.92 ± 1.50 at the respective rates. Trimethoprim decreased the CLR of rhodamine 123 in an infusion rate-dependent manner: 11.5 ± 1.3 (control), 5.17 ± 1.55, 1.31 ± 0.50, and 0.532 ± 0.180. These results suggest that Mate1 mediates the tubular secretion of trimethoprim, and at therapeutic doses, MATEs-mediated efflux can be saturated, and thereby, cause drug interactions with other MATE substrates.  相似文献   
63.
目的了解上海市黄浦区社会办医疗美容机构的管理人员和医师对《医疗美容管理办法》相关内容的掌握情况,发现存在的问题并提出改善建议.方法采用现场调查与现场问卷调查相结合的方式,对在上海市黄浦区开展医疗美容科目的所有社会办医疗机构(共计38家)进行全覆盖现场调查,并对其中的管理人员41人、相关医师31人进行问卷调查.结果38家社会办医疗美容机构中,美容外科和美容皮肤科的开展率较高,分别为96.8%和97.2%,而美容牙科开展率为52.4%,美容中医科开展率最低(25.0%).管理人员关于非主诊医师可在主诊医师指导下工作的知晓率仅68.3%.关于美容外科、皮肤科、中医科、牙科主诊医师应具备的工作年限,管理人员答对率为90.2%,医师答对率为72.0%,二者有显著性差异(P<0.05).结论社会办医疗美容机构中的二级科目设置需进一步优化,以减少资源空置.应加强对医疗机构管理人员和医师的法律培训,改变经营模式,制定明确的准入与退出机制,从而减少违法违规行为的发生.  相似文献   
64.
目的 分析重症医学科PBL教学法在临床心肺复苏术教学中的应用效果.方法 本次实验的开展基础数据选择2016年9月—2018年7月进入医院重症医学科实习学生64例,按照学生自身意愿以及学校安排将参与实验学生分为均数相同的两个小组(对照组、观察组),每组实验人数均为32例,其中对照组(n=32)采用传统教学方法 ,观察组(n=32)则应用PBL教学法教学,对比两组学生在学期结束后整体的学习质量情况和教学满意率.结果 观察组学生经过测试后理论知识和专业技能得分均对比对照组更高,教学效果更加理想,观察组学生对于教学的满意率评价更高,P<0.05.结论 重症医学科临床心肺复苏术教学中应用PBL教学法,将理论与实践进行结合,对教学方法 进行改进,全面提升学生的思维理解能力,培养良好的动手能力,促进理论教学与实践的结合,为学生以后的职业生涯提供更加理想的条件.  相似文献   
65.
66.
ObjectiveThe aim of this study was to discuss the clinical characteristics and the prognosis of surgically diagnosed endometriosis complicated by endometrial polyps and investigate the association between pregnancy outcomes during subsequent pregnancies.Materials and methodsFrom January 2013 to December 2016, 1263 infertile patients were enrolled in the study. We identified 451 patients with endometriosis, and divided them into a polyp group (n = 204) and a non-polyp group (n = 247) based on whether or not they were associated with endometrial polyps. Postoperative clinical pregnant women (n = 82) among the polyp group were then classified into a study group and a control group composed of those undergoing a singleton pregnancy (n = 164) who delivered during the same time period. Clinical statuses and complications during pregnancy and delivery were collected from hospitals and by telephone interviews and surveys through the mail.ResultsThe prevalence rate of endometriosis infertile group was obviously higher than the non-endometriosis infertile group ([45.23%; 204/451] versus [17.12%; 139/812]). Women suffering from stage 1 to 4 endometriosis had a 42.44% (73/172), 40.69% (59/145), 55.89% (38/68) and 51.52% (34/66) occurrence rate of endometrial polyps, respectively. The frequency of endometrial polyps for stage 3 and 4 patients was obviously higher than that of stage 1 and 2 patients ([53.73%; 72/134] versus [41.64%; 132/317]). Moreover, the occurrence rate of deep infiltrating endometriosis (DIE) was 57.81% (37/64), which was obviously higher than that of ovarian endometriosis (42.42%; 98/231) and peritoneal endometriosis (44.23%; 69/156). Of the 204 women diagnosed with posterior endometrial polyps, 89 became pregnant, 7 pregnancies ended in a spontaneous abortion, and 82 successfully delivered a baby. The clinical pregnancy rate of patients in stages 1 and 2 was wholly higher than that of patients in stages 3 and 4 ([48.70%; 56/115] versus [37.71%; 26/82]). The postsurgical pregnancy status of patients suffering from peritoneal endometriosis was slightly better than those with ovarian or DIE, but differences were not statistically significant (P = 0.626). We also found that the pregnancy rate was statistically elevated in patients whose EFI scores range from 7 to 10. When compared to the control group, women with endometriosis and endometrial polyps had a higher risk of their pregnancy being complicated by placenta previa (13.41%) and cesarean delivery (59.76%).ConclusionPatients with endometriosis have a higher frequency of endometrial polyps. We found that a combined hysteroscopy and laparoscopy surgical procedure is an effective way to increase pregnancy rates. Different endometriosis stages and types in patients were associated with clinical pregnancy and spontaneous abortion rates. Women affected by both endometriosis and endometrial polyps have an independently elevated risk of placenta previa and cesarean delivery during pregnancy.  相似文献   
67.
68.
The peri-implantation period of pregnancy is critical for conceptus development, implantation, and signaling for establishment of pregnancy. This study evaluated the effects of bisphenol A (BPA) on proliferation, adhesion, and migration of porcine trophectoderm (pTr2) cells, expression of transporters of arginine and synthesis of amino acids. All concentrations of BPA decreased proliferation and adhesion of pTr2 cells after 96 h compared to the control group. Lower concentrations of BPA (1 × 10−9, 1 × 10-8, 10-7M) increased (P < 0.05), but higher concentrations of BPA (1 × 10-5, 1 × 10-4 M) decreased migration of pTr2 cells. BPA increased expression of SLC7A1 mRNA at lower concentrations (1 × 10−9 to 1 × 10-6M) and SL7A6, another cationic acid transporter, at higher concentrations (1 × 10-5, 1 × 10-4 M). BPA also down-regulated the expression of IGF1 and IGF1 receptor at concentrations of 1 × 10-7 to 1 × 10-4 M compared to the control group. The expression of mRNAs for aquaporins (AQP) 3 and 4 were reduced at all concentrations of BPA, but at lower concentrations of BPA, (1 × 10−9 to 1 × 10-8M) expression of AQP9 mRNA increased and the expression of AQP11 was not affected by BPA (P > 0.05). There was an inhibitory effect of BPA on the release of synthesis of asparagine, threonine, taurine, tryptophan, and ornithine into the culture medium by pTr2 cells. Collectively, BPA adversely affected the expression of transporters for cationic amino acids like arginine, as well as AQPs, IGF1, and IGF1R associated with proliferation, migration, and adhesion of pTr2 cells. Those adverse effects would likely increase pregnancy losses during the peri-implantation period of pregnancy.  相似文献   
69.
70.
《Enfermería clínica》2020,30(6):411-418
ObjectiveTo describe perceptions and wishes regarding childbirth in a group of full-term pregnant women in Zamora.MethodQualitative study of phenomenological character. Participants and scope of study: pregnant women (37-38 weeks), Zamora Sur and Santa Elena health centres (Zamora, Spain). Data collection: semi-structured interviews, until data saturation (16 interviews). Data analysis: analysis of thematic content.ResultsThe maternal feelings varied from joy to fear or stress. The interviewees said they did not feel capable of enduring the pain of childbirth. The needs that they felt most important were having support and accompaniment during delivery (especially of their partner) and receiving good treatment from the healthcare workers.ConclusionsThe importance and repercussion of childbirth for women are not only biological, but also largely mental, emotional and social. It is conditioned by multiple factors: maternal feelings, their ability to deal with the pain of childbirth, their needs, the changes they have made, the support they have and the health professionals who care for them.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号