全文获取类型
收费全文 | 22967篇 |
免费 | 1880篇 |
国内免费 | 104篇 |
专业分类
耳鼻咽喉 | 367篇 |
儿科学 | 844篇 |
妇产科学 | 553篇 |
基础医学 | 2561篇 |
口腔科学 | 734篇 |
临床医学 | 1769篇 |
内科学 | 5110篇 |
皮肤病学 | 715篇 |
神经病学 | 1294篇 |
特种医学 | 763篇 |
外国民族医学 | 6篇 |
外科学 | 4107篇 |
综合类 | 530篇 |
一般理论 | 7篇 |
预防医学 | 1689篇 |
眼科学 | 613篇 |
药学 | 1691篇 |
中国医学 | 128篇 |
肿瘤学 | 1470篇 |
出版年
2023年 | 214篇 |
2022年 | 713篇 |
2021年 | 1072篇 |
2020年 | 628篇 |
2019年 | 920篇 |
2018年 | 1109篇 |
2017年 | 778篇 |
2016年 | 843篇 |
2015年 | 838篇 |
2014年 | 1084篇 |
2013年 | 1408篇 |
2012年 | 1762篇 |
2011年 | 1840篇 |
2010年 | 1147篇 |
2009年 | 1040篇 |
2008年 | 1252篇 |
2007年 | 1230篇 |
2006年 | 1184篇 |
2005年 | 988篇 |
2004年 | 915篇 |
2003年 | 704篇 |
2002年 | 638篇 |
2001年 | 350篇 |
2000年 | 374篇 |
1999年 | 277篇 |
1998年 | 129篇 |
1997年 | 98篇 |
1996年 | 95篇 |
1995年 | 64篇 |
1994年 | 59篇 |
1993年 | 53篇 |
1992年 | 60篇 |
1991年 | 60篇 |
1990年 | 49篇 |
1989年 | 46篇 |
1988年 | 47篇 |
1987年 | 45篇 |
1986年 | 25篇 |
1985年 | 47篇 |
1984年 | 95篇 |
1983年 | 83篇 |
1982年 | 61篇 |
1981年 | 37篇 |
1980年 | 57篇 |
1979年 | 54篇 |
1978年 | 52篇 |
1977年 | 46篇 |
1976年 | 42篇 |
1975年 | 48篇 |
1974年 | 32篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
PURPOSE: To compare the analgesic effects of dexmedetomidine/morphine with those of tramadol/midazolam in patients undergoing extracorporeal shockwave lithotripsy (ESWL) for urinary calculi. METHODS: Sixty patients were randomized to receive either dexmedetomidine 1 micro g*kg(-1) iv followed by 0.5 micro g*kg(-1)*hr(-1) infusion together with morphine patient-controlled analgesia [(PCA); 2 mg bolus, five minutes lockout, 2 mg*hr(-1) infusion; (Group DEX)], or tramadol 1.5 mg*kg(-1) pre-mixed with midazolam 30 micro g*kg(-1) iv followed by tramadol PCA [20 mg bolus, five minute lockout, 20 mg*hr(-1) infusion; (Group TRA)]. Pain was assessed at baseline and every 15 min thereafter. Patients' and urologist's satisfaction with analgesia and sedation were determined on a seven-point scale ranging from 1 (extremely dissatisfied) to 7 (extremely satisfied). Patient's discharge time was also documented. RESULTS: Visual analogue scale scores over time were consistently lower in Group DEX compared with Group TRA (P = 0.001). Patients' satisfaction with analgesia (5 +/- 1 vs 4 +/- 2, P = 0.012) and with sedation (6 +/- 1 vs 5 +/- 1, P = 0.020), and urologist's satisfaction (6 +/- 1 vs 4 +/- 2, P = 0.001) were all higher amongst Group DEX patients compared with Group TRA. There was no difference between discharge times of patients in Group DEX compared with those in Group TRA [85 (60,115) min vs 65 (40,95) min, P = 0.069]. CONCLUSION: Dexmedetomidine in combination with morphine PCA provided better analgesia for ESWL and was associated with higher patients' and urologist's satisfaction when compared with a tramadol/midazolam PCA combination. 相似文献
33.
34.
35.
Phyllis W Sharps Ayman A E El-Mohandes M Nabil El-Khorazaty Michele Kiely Tessa Walker 《Journal of perinatology》2003,23(5):414-419
OBJECTIVE: To describe breastfeeding initiation among 210 urban African-American mothers with inadequate prenatal care. METHODS: This study is a case-control study of postpartum mothers recruited from four large urban hospitals. RESULTS: Mothers who chose to breastfeed were more educated, employed before birth, married, and using contraception postnatally. Regression model analysis controlling for demographic differences revealed that breastfeeding was significantly associated with a higher perception of severity of illness and higher confidence in the ability of health care to prevent illness. Breastfeeding mothers were less likely to reverse parent-child roles and had a lower perception of hassle from their infant's behavior. When comparing mothers who breastfed longer than 8 weeks to those who did not breastfeed, breastfeeding mothers had high scores related to empathy toward infants on the Adult-Adolescent Parenting Inventory as well as a low perception of hassle on the Parenting Daily Hassle. The perception of existing formal or informal social support did not influence breastfeeding behavior. CONCLUSION: Personal attributes of low-income urban mothers such as health beliefs and parental attitudes may play a role in the initiation and duration of breastfeeding. Low-income African-American mothers may be influenced in their choice to breastfeed by supportive messages from physicians and nurses delivering care to mothers and their newborns. Emphasis should be placed on the role breastfeeding can play in preventing childhood illnesses. 相似文献
36.
Dr. med. Dipl.-Soz. T. Krones E. Schlüter S. El Ansari T. Wissner R. Zoll G. Richter 《Gyn?kologische Endokrinologie》2004,2(4):245-250
Preimplantation genetic diagnosis (PGD) has been vigorously debated in Germany ever since the Bundesärztekammer (BÄK) published a draft of guidelines for PGD in March 2000. Many stakeholders such as churches, medical societies, and diverse associations have participated in the discussion. However, little is known about the attitudes of experts, directly affected patient groups, and the public in Germany. In several studies that are part of the German research program on ethical implications of the Human Genome Project, representative surveys were undertaken to assess the attitudes of the general population (n=1017), five relevant expert groups (n=879), and couples at high risk for genetic disorders(n=324) towards PGD and prenatal diagnosis (PD). All groups favor legislation for PGD. Differences exist in regard to the extent of their approval. For 17% of the high-risk couples with a persisting desire for a child, PGD performed in a neighboring country is the most probable reproductive option. These results should be carefully considered in the ongoing legislation process on human reproduction in our country. 相似文献
37.
D Loutradis K Stefanidis P Drakakis K Kallianidis A El Sheikh S Milingos K Siskos S Michalas 《Gynecological endocrinology》2003,17(2):101-106
The purpose of this study was to investigate the ovarian response and the receptivity of the endometrium in women pre-treated with micronized progesterone. Eighty-two normogonodotropic women undergoing in vitro fertilization were studied. Thirty received micronized progesterone 1500 mg/day from day 21 of the cycle for a minimum of 2 weeks, and 52 did not receive micronized progesterone (control group). A gonadotropin releasing hormone agonist (GnRH-a) was administered to all the patients in the follicular phase (flare-up). Twenty-five cycles were cancelled for fertilization failure due to male factor, 12 (40%) in the progesterone group and 13 (25%) in the control group (p = 0.271). There was no difference in the number of oocytes retrieved (7.3 +/- 5 vs. 8.2 +/- 4), fertilization rate (50.8% vs. 65%), clinical pregnancy rate (16.6% vs. 25%) or implantation rate (8% vs. 14%). In the progesterone group cases without fertilization, we performed two biopsies to evaluate the receptivity of the endometrium. Pinopode expression was noted 7 days after oocyte retrieval. It seems that the administration of micronized progesterone in the previous cycle does not affect the ovarian response to the combination of follicular phase GnRH-a and gonadotropins, nor the receptivity of the endometrium. 相似文献
38.
R. El Galta C. M. Van Duijn J. C. Van Houwelingen J. J. Houwing-Duistermaat 《Annals of human genetics》2005,69(4):373-381
In genetic epidemiological studies informative families are often oversampled to increase the power of a study. For a proband‐family design, where relatives of probands are sampled, we derive the score statistic to test for clustering of binary and quantitative traits within families due to genetic factors. The derived score statistic is robust to ascertainment scheme. We considered correlation due to unspecified genetic effects and/or due to sharing alleles identical by descent (IBD) at observed marker locations in a candidate region. A simulation study was carried out to study the distribution of the statistic under the null hypothesis in small data‐sets. To illustrate the score statistic, data from 33 families with type 2 diabetes mellitus (DM2) were analyzed. In addition to the binary outcome DM2 we also analyzed the quantitative outcome, body mass index (BMI). For both traits familial aggregation was highly significant. For DM2, also including IBD sharing at marker D3S3681 as a cause of correlation gave an even more significant result, which suggests the presence of a trait gene linked to this marker. We conclude that for the proband‐family design the score statistic is a powerful and robust tool for detecting clustering of outcomes. 相似文献
39.
Hassan Chamsi-Pasha Alaa Abdulmoneim Waqar H Ahmed Khaled F Al-Shaibi Aref Ajam Hassan Bakhamees Abdullah K Ashmeg 《Journal of the American Society of Echocardiography》2004,17(1):70-72
A 24-year-old man presented with a 24-hour history of pain and numbness in his left arm. The patient's clinical presentation of peripheral embolism was corroborated by angiography. Echocardiographic study showed masses in both right and left atria. Pathologic specimen from the embolus confirmed the diagnosis of aspergillosis. 相似文献
40.
Conference Reports: This section contains reports on topical conferences. Reports are usually written at the request of the editorial office, but unsolicited contributions are also welcome. Suggestions should be sent to the editorial office of the Macromolecular journals, preferably by E‐mail to macromol@wiley‐vch.de. 相似文献