全文获取类型
收费全文 | 49863篇 |
免费 | 2755篇 |
国内免费 | 101篇 |
专业分类
耳鼻咽喉 | 386篇 |
儿科学 | 1936篇 |
妇产科学 | 1304篇 |
基础医学 | 6903篇 |
口腔科学 | 1001篇 |
临床医学 | 6653篇 |
内科学 | 9513篇 |
皮肤病学 | 914篇 |
神经病学 | 4945篇 |
特种医学 | 1167篇 |
外科学 | 4310篇 |
综合类 | 453篇 |
一般理论 | 62篇 |
预防医学 | 5901篇 |
眼科学 | 716篇 |
药学 | 2729篇 |
2篇 | |
中国医学 | 55篇 |
肿瘤学 | 3769篇 |
出版年
2024年 | 307篇 |
2023年 | 469篇 |
2022年 | 614篇 |
2021年 | 1328篇 |
2020年 | 1036篇 |
2019年 | 1525篇 |
2018年 | 1568篇 |
2017年 | 1225篇 |
2016年 | 1348篇 |
2015年 | 1422篇 |
2014年 | 1808篇 |
2013年 | 2668篇 |
2012年 | 3703篇 |
2011年 | 3833篇 |
2010年 | 2105篇 |
2009年 | 1864篇 |
2008年 | 3090篇 |
2007年 | 3187篇 |
2006年 | 3129篇 |
2005年 | 2956篇 |
2004年 | 2858篇 |
2003年 | 2634篇 |
2002年 | 2358篇 |
2001年 | 412篇 |
2000年 | 293篇 |
1999年 | 345篇 |
1998年 | 529篇 |
1997年 | 404篇 |
1996年 | 362篇 |
1995年 | 350篇 |
1994年 | 278篇 |
1993年 | 278篇 |
1992年 | 213篇 |
1991年 | 183篇 |
1990年 | 169篇 |
1989年 | 118篇 |
1988年 | 145篇 |
1987年 | 104篇 |
1986年 | 113篇 |
1985年 | 114篇 |
1984年 | 111篇 |
1983年 | 113篇 |
1982年 | 137篇 |
1981年 | 125篇 |
1980年 | 108篇 |
1979年 | 64篇 |
1978年 | 68篇 |
1977年 | 49篇 |
1976年 | 47篇 |
1972年 | 36篇 |
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
1.
2.
Carmine Nieuwstraten N Renee Labiris Anne Holbrook 《Revue canadienne de psychiatrie》2006,51(5):300-316
OBJECTIVE: Antidepressants are commonly used drugs with potential for numerous drug interactions. This study aims to systematically review the literature on drug interactions with antidepressants. METHODS: We searched MEDLINE (1966 to November 2003) and EMBASE (1980 to 2003), using the heading drug interactions combined with individual antidepressant names. We restricted searches to English-language articles and human studies. We screened drug interaction texts and review articles for relevant studies. We included articles reporting original human data on drug interactions with antidepressants commonly used in North America. Articles were independently evaluated by 2 reviewers on clinical effect, clinical significance, and quality of evidence. Discrepancies were resolved by consensus. RESULTS: There were 904 eligible interactions, involving 9509 patients, for a total of 598 summary interactions. Of these, 439 (73%) demonstrated an interaction, 148 (25%) had no effect, and 11 (2%) had conflicting evidence. For 510 interactions (85%), the quality of evidence was poor. It was fair for 67 (11%) interactions and good for 10 (2%) interactions. There were no interactions with excellent quality of evidence. There were 145 (24%) interactions of major clinical significance. These were predominantly hypertensive emergencies and serotonin syndrome. Most interacting drugs had central nervous system (CNS) activity. As expected, monoamine oxidase inhibitors (MAOIs) appear to be the most problematic family in terms of potential for serious drug interactions. CONCLUSIONS: Drug interactions with antidepressants are an important cause for concern, but this concern is based primarily on poor evidence. We recommend caution when combining antidepressants with other CNS drugs, particularly when coadministering MAOIs with other substances. 相似文献
3.
Anne Pavy-Le Traon Richard L Hughson Claire Thalamas Monique Galitsky Nelly Fabre Olivier Rascol Jean-Michel Senard 《Movement disorders》2006,21(12):2122-2126
Patients with multiple system atrophy (MSA) present large changes in blood pressure (BP) due to autonomic disturbances. We analyzed how this change may influence dynamic cerebral autoregulation (DCA). Simultaneous recordings of arterial BP (Finapres) and middle cerebral artery (MCA) blood flow velocity (BFV) (transcranial Doppler) were performed in 10 patients with MSA (61 +/- 12 yr of age) and 12 healthy volunteers (61 +/- 11 yr of age): cerebral BFV response to oscillations in mean BP was studied in the supine position by cross-spectral analysis of mean BP and mean MCA BFV. The DCA was also studied during the decrease in BP the first seconds when standing up from a sitting position by the assessment of the cerebrovascular resistance index (CR; mean BP/mean MCA BFV ratio). The MCA BFV/BP cross-spectral analysis showed a phase for the mid-frequency band (0.07-0.2 Hz) significantly larger in MSA, suggesting more active autoregulation in response to larger changes in BP. Changes in CR reflecting the rate of autoregulation, when standing did not differ between the two groups. These data suggest that dynamic cerebral autoregulation is preserved in MSA. 相似文献
4.
Postpartum fatigue is a normal condition that most women experience. Breastfeeding is often associated in women's minds as contributing to the feeling of overall perceived fatigue, and many women indicate that they have ceased breastfeeding because of fatigue. However, the relationship between feeding choice and perceived fatigue has never been established. Two hundred and fifty-three women participated in a study examining whether perceived fatigue differed for bottle-feeding and breastfeeding women at 3 different times during the postpartum period (2-4 days, 6 weeks, and 12 weeks postpartum). Results showed no significant differences for these 2 groups, suggesting that perceived fatigue during the postpartum period is not dependent on feeding choice. Additional analyses examining other variables with a potential effect were nonsignificant. Because perceived physical fatigue does not appear to be dependent on feeding choice, women should be prepared for the feeling of perceived fatigue during the postpartum period while at the same time be reassured that feeding choice is not correlated. 相似文献
5.
This paper provides a comprehensive methodological review of the literature assessing the relationship between marital satisfaction and communication. The investigations vary greatly in the adequacy of their assessment measures and soundness of their research design. Although it is generally concluded that both content and process communication are related to marital satisfaction, replication of the better designs is necessary. Specific findings and their practical implications for both future research and marital therapy are discussed. 相似文献
6.
7.
Najat C Daw Wayne L Furman Clinton F Stewart Lisa C Iacono Mark Krailo Mark L Bernstein Janet E Dancey Rose Anne Speights Susan M Blaney James M Croop Gregory H Reaman Peter C Adamson 《Journal of clinical oncology》2005,23(25):6172-6180
PURPOSE: Epidermal growth factor receptor is expressed in pediatric malignant solid tumors. We conducted a phase I trial of gefitinib, an epidermal growth factor receptor tyrosine kinase inhibitor, in children with refractory solid tumors. PATIENTS AND METHODS: Gefitinib (150, 300, 400, or 500 mg/m2) was administered orally to cohorts of three to six patients once daily continuously until disease progression or significant toxicity. Pharmacokinetic studies were performed during course one (day 1 through 28). RESULTS: Of the 25 enrolled patients, 19 (median age, 15 years) were fully evaluable for toxicity and received 54 courses. Dose-limiting toxicity was rash in two patients treated with 500 mg/m2 and elevated ALT and AST in one patient treated with 400 mg/m2. The maximum-tolerated dose was 400 mg/m2/d. The most frequent non-dose-limiting toxicities were grade 1 or 2 dry skin, anemia, diarrhea, nausea, and vomiting. One patient with Ewing's sarcoma had a partial response. Disease stabilized for 8 to > or = 60 weeks in two patients with Wilms' tumor and two with brainstem glioma (one exophytic). At 400 mg/m2, the median peak gefitinib plasma concentration was 2.2 microg/mL (range, 1.2 to 3.6 microg/mL) and occurred at a median of 2.3 hours (range, 2.0 to 8.3 hours) after drug administration. The median apparent clearance and median half-life were 14.8 L/h/m2 (range, 3.8 to 24.8 L/h/m2) and 11.7 hours (range, 5.6 to 22.8 hours), respectively. Gefitinib systemic exposures were comparable with those associated with antitumor activity in adults. CONCLUSION: Oral gefitinib is well tolerated in children. Development of the drug in combination with cytotoxic chemotherapy will be pursued. 相似文献
8.
Acta Endoscopica - C’est un test de sélection. C’est un outil important de communication et d’information, c’est dire si elle doit être connue, comprise et bien... 相似文献
9.
Sylvia J T Jansen Wilma Otten Anne M Stiggelbout 《Journal of clinical oncology》2004,22(15):3181-3190
PURPOSE: Many studies have determined cancer patients' preferences for adjuvant therapy, for example, by asking patients the extent of benefit they would need in order to accept the therapy. However, little is known about the determinants that influence these preferences. Our research goal was to explore which determinants underlie patients' preferences by means of a literature review. METHODS: PubMed searches were conducted to identify studies in which cancer patients' preferences for adjuvant therapy had been elicited by means of a treatment preference instrument. Twenty-three papers were evaluated with regard to reported relationships between preferences and potential determinants. A total of 40 determinants were recorded and classified into one of seven categories: (1) treatment-related determinants, (2) sociodemographic characteristics and current quality of life, (3) clinical characteristics, (4) measurement instrument-related determinants, (5) time-related determinants, (6) cognitive/affective determinants, and (7) specialist-related determinants. Results: The benefit and toxicity of treatment, experience of the treatment, and having dependents (eg, children) living at home were important determinants of patients' preferences. Furthermore, qualitative data suggested that cognitive/affective and specialist-related determinants might have a large impact on patients' treatment preferences. CONCLUSION: Our results show that patients' preferences cannot fully be explained on the basis of treatment-related determinants and patient and clinical characteristics. More research is needed in the area of cognitive/affective and specialist-related determinants because of the lack of quantitative results. Furthermore, we recommend carrying out larger studies in which the (internal) relationships between determinants and preferences are assessed in the context of a cognitive cost-benefit model. 相似文献
10.
OBJECTIVE: Based on recent safety and efficacy data, combined with the known pharmacokinetic parameters of aminoglycosides in the newborn, once-daily gentamicin should be preferable to the many other dosing regimens currently in use. Although there are growing data to support its use in term newborns, experience with preterm infants is more limited. In our Neonatal Intensive Care Unit, we experienced difficulties regarding complicated dosing regimens, actual dosing errors, and the tendency to check trough and peak levels around the third dose for infants receiving only a 48 hour course. Therefore, we conducted a quality improvement initiative in which we developed and tested a clinical practice guideline for the use of once-daily gentamicin for preterm and term infants that we hoped would yield trough and peak levels in our target range. METHODS: We combined a review of the published English language literature with pharmacokinetic analysis of our own data prior to initiation of this new regimen to design the following dosing regimen: <35 weeks gestation: 3 mg/kg q 24 hours, > or =35 weeks gestation: 4 mg/kg q 24 hours. Our goal serum levels were a trough < or =2 microg/ml and a peak between 6 and 12 microg/ml. We collected and analyzed trough and peak levels from all infants receiving this dosing regimen in the first week of life for at least 72 hours between 3/1/99 and 12/31/00. RESULTS: In total, 214 babies met our inclusion criteria, 75 of whom were <35 weeks gestation. 100% of babies of all gestational ages had a nontoxic trough level. For infants <35 weeks gestation, 79% had a therapeutic peak level, with a mean value of 6.8 microg/ml. For infants of at least 35 weeks gestation, 93% had a therapeutic peak level, with a mean value of 8.4 microg/ml. 92% of nontherapeutic peaks were too low. CONCLUSION: This study of once-daily gentamicin represents the largest sample size of pre-term infants published to date. The proposed regimen is simple and yields a high proportion of desirable levels. We recommend it for use in preterm and term newborns. 相似文献