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   24304篇
  免费   1553篇
  国内免费   161篇
耳鼻咽喉   292篇
儿科学   777篇
妇产科学   714篇
基础医学   2446篇
口腔科学   717篇
临床医学   2007篇
内科学   5244篇
皮肤病学   522篇
神经病学   1101篇
特种医学   966篇
外国民族医学   9篇
外科学   4323篇
综合类   734篇
现状与发展   1篇
一般理论   21篇
预防医学   1662篇
眼科学   712篇
药学   2112篇
中国医学   157篇
肿瘤学   1501篇
  2023年   291篇
  2022年   806篇
  2021年   1403篇
  2020年   741篇
  2019年   937篇
  2018年   1249篇
  2017年   754篇
  2016年   777篇
  2015年   875篇
  2014年   1078篇
  2013年   1332篇
  2012年   1820篇
  2011年   1864篇
  2010年   970篇
  2009年   800篇
  2008年   1175篇
  2007年   1259篇
  2006年   1101篇
  2005年   958篇
  2004年   896篇
  2003年   761篇
  2002年   705篇
  2001年   338篇
  2000年   325篇
  1999年   297篇
  1998年   177篇
  1997年   153篇
  1996年   128篇
  1995年   127篇
  1994年   84篇
  1993年   68篇
  1992年   137篇
  1991年   125篇
  1990年   122篇
  1989年   112篇
  1988年   111篇
  1987年   113篇
  1986年   118篇
  1985年   99篇
  1984年   78篇
  1983年   93篇
  1982年   46篇
  1981年   58篇
  1980年   45篇
  1979年   80篇
  1978年   51篇
  1977年   59篇
  1976年   48篇
  1975年   49篇
  1974年   38篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
941.
International Urology and Nephrology - To evaluate the role of combination of N-acetylcysteine with stepwise ramping voltage in renal protection against the ischemic, vascular and oxidative effects...  相似文献   
942.
The current study aimed to investigate the protective potential of Chlorella Vulgaris (CV) extract against the reproductive dysfunction induced by sodium nitrite toxicity. Forty-five male Wistar albino rats were assigned into five groups (n = 9). Control group received normal saline orally for 3 months, CV-treated: administered CV extract (70 mg/kg.BW) orally for 3 months, sodium nitrite-treated: received sodium nitrite (80 mg/kg.BW) orally for 3 months, co-treated: simultaneously received CV along with sodium nitrite treatment, orally, daily for 3 months, and CV-pre-treated: pre-treated with CV extract for 4 weeks followed by simultaneous treatment with sodium nitrite and CV extract for additional 8 weeks. Treatment with sodium nitrite significantly decreased serum testosterone and follicle-stimulating hormone concentrations, sperm count, motility, and viability. Besides, it decreased testicular superoxide dismutase and glutathione peroxidase activities while increased malondialdehyde concentration. This effect of sodium nitrite was associated with degenerative, necrotic, vascular, and inflammatory changes in testicular tissues. Treatment of sodium nitrite-intoxicated rats with CV in co-treated and pre-treated groups significantly prevented sodium nitrite-induced alterations of sperm parameters, hormonal concentrations, testicular oxidative–antioxidant status, and histological architecture. This study indicates that CV extract ameliorates the reproductive dysfunction induced by sodium nitrite toxicity via improving reproductive hormonal levels and testicular antioxidant activities.  相似文献   
943.
Among various health issues, infertility has been always considered as one of the major health problems. Idiopathic infertility is still a matter of debate since the underlying mechanisms stay obscure. Idiopathic infertility is related to expanded chance of metabolic syndrome components, obesity and increased risk of cardiovascular diseases. This study aimed to assess insulin resistance and serum levels of irisin as one of the adipokines in patients with idiopathic infertility. This study included 50 male patients aged 25–50 years old suffering from idiopathic infertility, together with 50 healthy individuals of matched age as controls. Patients showed significantly increased homeostasis model assessment for insulin resistance values than controls. For irisin results, idiopathic infertility patients had significantly decreased values than controls indicating the potential effect of irisin in development of insulin resistance in idiopathic infertility patients.  相似文献   
944.
945.
946.
Islam is the second most practiced religion globally, and the number of Muslims in Western countries has been increasing due to recent trends in migration. Studies have shown that Muslims in the Western world have more negative attitudes toward organ donation and transplantation compared with individuals from other religious backgrounds. Multiple barriers have been postulated that may prevent Muslims from exploring organ donation or transplantation. We conducted a literature review with the goal of summarizing the opinions of major Sunni and Shia scholars and Islamic bodies about organ donation and transplantation, including their opinions and rulings on the neurological determination of death to inform healthcare professionals, community members, and leaders. We also identified factors and attitudes that may prevent members of the Muslim community from achieving equitable access to transplantation or from consenting to donate organs during life or after death. Key factors or concerns identified included: lack of information regarding organ donation, mistrust of the healthcare system, family opinions, sacredness of the body, lack of clear understanding of religious rulings, and opinions of religious leaders. Studies have suggested that partnering with religious leaders to address these concerns may help foster positive attitudes toward organ donation and transplantation.  相似文献   
947.
The current study was aimed to assess Saudi school students’ knowledge, attitude and practice about medicines. A pretested self-administered questionnaire was used anonymously among 15–20 year-old adolescents attending tertiary schools in Taif City, KSA. A total of 1022 students completed the questionnaires. Only 15.4% of the respondents knew the medicines’ uses. Most of the students 79.6% affirmed that they used to take medicines after consulting physicians, and 45.1% of the students thought that tablet size affects the medicine’s efficacy. More than half of the students knew that high temperatures affect the efficacy of medicines, there was a significant difference between rural and urban areas (= 0.005). Physicians (50.6%) and community pharmacists (15.7%), were the main students’ reliable sources of information about medicines. The majority of the students 70.5% were interested in learning more about medicines. The younger students ⩽18 years wish to learn more than the older ones (P < 0.014). The study showed that Saudi school students aged 15–20 years old have poor knowledge, misconception and negative attitudes about medicines. Low level of knowledge may expose adolescents to health-related problems. Educational efforts are important to improve students’ practice toward medicines.  相似文献   
948.

Objective

Medication use during pregnancy is a major concern for most women. The aim of the present study was to assess medication use, knowledge and beliefs about medications among pregnant women in Saudi Arabia.

Methods

More than 760 pregnant women, attending the obstetric clinic, filled a semi-structured questionnaire. Data were collected about their sociodemographic background, medication use during pregnancy, medication/pregnancy risk awareness, sources of drug information and beliefs about medications.

Results

Most women had a positive attitude toward medications in general but they believed pregnant women should be more cautious regarding drug-use during pregnancy. A significant association was found between participants’ education and occupation, and beliefs about medications. In this context, well educated women and those working in a health-related career demonstrated more correct beliefs about medications. Women with health-related occupations were more knowledgeable about the life saving effect of drugs on unborn children. Women indicated inadequate provision of drug-related information from physician and pharmacist; they rely on medication pamphlet to get such information. The most frequently used drugs were paracetamol and vitamins (13.2%). Most pregnant women (59.2%) were able to identify drugs to-be avoided in pregnancy that agreed roughly with FDA categories with 23 hits out of 32. They indicated that newborn anomalies (6.5%) were not attributed to drug-use during pregnancy.

Conclusion

During pregnancy, women were more conservative and skeptic toward medication, health-care professionals should be aware of such attitudes when advising pregnant women to take medication.  相似文献   
949.
A library of 2,5-disubstituted 1,3,4-oxadiazole derivatives of (E)-2-aryl-5-(3,4,5-trimethoxystyryl)-1,3,4-oxadiazoles 4(ao) and (E)-2-aryl-5-(2-benzo[d][1,3]dioxol-5-yl)vinyl)-1,3,4-oxadiazoles 5(aq) were synthesized and evaluated for their in vitro acetylcholinesterase (AChE) inhibitory activity. All the synthesized compounds exhibited moderate to good inhibitory activity toward the AChE enzyme. Among the oxadiazole derivatives examined, compounds 4a, 4g, 5c, and 5m (IC50 values of 24.89, 13.72, 37.65, and 19.63 μM, respectively) were found to be promising inhibitors of AChE. Molecular protein–ligand docking studies were examined for these compounds using GOLD docking software and their binding conformations were determined and the simultaneous interactions mode was also established for the potent derivatives.  相似文献   
950.
A one pot, economical, and efficient synthesis of 1-(4-acetylphenyl)-3-aryloxypyrrolidine-2,5-diones-based derivatives 5a-l have been accomplished in single steps and in satisfactory yields from 1-(4-acetylphenyl)-pyrrole-2,5-diones 3 and phenols 4al. All the compounds were characterized by physical, spectroscopic, and elemental analysis. The selection of the bioassays was based on proving the drug receptor binding concept. Compounds 5g, 5k, 5h, 5i, 5a, and 5f showed the highest inhibitory antioxidant activity using ABTS methods. Compounds 5k, 5g, 5c, 5h, 5b, 5d, 5f, and 5j manifested the best protective effect against DNA damage induced by bleomycin. Moreover, an in-vitro cytotoxic activity evaluation of all synthesized compounds was against four cancer cell lines using 5-Fluorouracil as a standard anticancer drug.  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