全文获取类型
收费全文 | 4965篇 |
免费 | 410篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 276篇 |
妇产科学 | 81篇 |
基础医学 | 664篇 |
口腔科学 | 152篇 |
临床医学 | 478篇 |
内科学 | 881篇 |
皮肤病学 | 90篇 |
神经病学 | 278篇 |
特种医学 | 546篇 |
外国民族医学 | 1篇 |
外科学 | 612篇 |
综合类 | 121篇 |
一般理论 | 3篇 |
预防医学 | 574篇 |
眼科学 | 38篇 |
药学 | 275篇 |
1篇 | |
中国医学 | 3篇 |
肿瘤学 | 319篇 |
出版年
2022年 | 26篇 |
2021年 | 80篇 |
2020年 | 50篇 |
2019年 | 72篇 |
2018年 | 95篇 |
2017年 | 69篇 |
2016年 | 81篇 |
2015年 | 73篇 |
2014年 | 117篇 |
2013年 | 179篇 |
2012年 | 159篇 |
2011年 | 187篇 |
2010年 | 117篇 |
2009年 | 151篇 |
2008年 | 159篇 |
2007年 | 186篇 |
2006年 | 189篇 |
2005年 | 173篇 |
2004年 | 163篇 |
2003年 | 157篇 |
2002年 | 144篇 |
2001年 | 161篇 |
2000年 | 138篇 |
1999年 | 123篇 |
1998年 | 153篇 |
1997年 | 150篇 |
1996年 | 136篇 |
1995年 | 96篇 |
1994年 | 114篇 |
1993年 | 127篇 |
1992年 | 110篇 |
1991年 | 94篇 |
1990年 | 78篇 |
1989年 | 116篇 |
1988年 | 114篇 |
1987年 | 94篇 |
1986年 | 97篇 |
1985年 | 87篇 |
1984年 | 59篇 |
1983年 | 56篇 |
1982年 | 55篇 |
1981年 | 59篇 |
1980年 | 48篇 |
1979年 | 58篇 |
1978年 | 52篇 |
1977年 | 55篇 |
1976年 | 38篇 |
1974年 | 34篇 |
1973年 | 25篇 |
1972年 | 28篇 |
排序方式: 共有5404条查询结果,搜索用时 15 毫秒
1.
2.
Birth weight on 12,644 singleton infants from 6,196 sibships born in Maryland between 1980 and 1984 were used to estimate the effects of nine maternal and infant covariates on the sibship correlation in birth weight. Assuming a homogeneous correlation across all families, the estimated intraclass correlation was 0.4664 (+/- 0.0099). This high sibship correlation makes it possible to predict, with reasonable accuracy, the birth weight of a child given information on previous sibs, as well as covariates on the mother and/or infant pertinent to a given pregnancy. The reduction in variance associated with incorporating information on the nine covariates used here was approximately equal to that obtained by conditioning on a single previous sib. Testing for heterogeneity in correlation among different groups of families showed that a crude measure of parity (first live birth vs. other), time between births, mother's marital status, and maternal age at the birth of the last child significantly influenced the sibship correlation in birth weight. 相似文献
3.
The precision and accuracy of manual reticulocyte counts using the Miller disc reticle, other ruled reticle and no reticle are compared with the reticulocyte results from the automated Hematrak 590 instrument. Two slides of each of 50 patient blood specimens were sent to the hematology laboratories of each of six participating hospitals. In addition to between-method comparison (precision), the manual method results using the three different counting techniques were each compared with the Hematrak results to determine if there were significant differences in reported results (accuracy). Statistical analysis revealed that the Miller disc method was the most precise and accurate manual method as compared with the Hematrak. Methods without a Miller disc reported significantly higher reticulocyte counts. Imprecision was also higher among non-Miller manual methods. By using the Miller disc, the accuracy and precision of manual methods may be increased to that of the automated Hematrak method. 相似文献
4.
ME BURGE AM JOSHUA CM McNEIL R HUI MJ BOYER R ABRAHAM 《Asia-Pacific Journal of Clinical Oncology》2005,1(1):47-52
Background: Pemetrexed and cisplatin have recently been shown to significantly improve survival compared with cisplatin alone. However, there are only limited data reflecting teaching hospital experience outside a clinical trial. Pemetrexed has only been available in Australia on a restricted basis since 2002. We reviewed our experience of patients treated on the Australian ‘Special Access Scheme’ at three major thoracic oncology units. Methods: Charts were reviewed for all patients enrolled on the scheme. Data was extracted on age, World Health Organization (WHO) performance status, histology, prior therapy, time from diagnosis to starting pemetrexed, chemotherapy (pemetrexed alone or with a platinum), cycle number, response rate, actuarial progression‐free and overall survival. Doses were cisplatin 75 mg/m2 or carboplatin AUC = 5 and pemetrexed 500 mg/m2 every 21 days. Results: 52 patients (32 male and 20 female) were reviewed. Median age was 58 years and 88% were WHO 0–1. Histology included 54% epithelial, 17% biphasic (epithelial and sarcomatoid) and 21% undefined. The median time from diagnosis to administration of pemetrexed was 145 days. Sixty‐five percent had minimal surgical intervention with video assisted thoracoscopy, pleurodesis and biopsy, while 19% had received prior palliative radiation. Seventy‐one percent were chemotherapy naïve, the remaining 29% having received previous platinum and/or gemcitabine regimens. Twenty‐three percent had pemetrexed alone, 35% in combination with carboplatin and 42% with cisplatin. The median number of cycles was 4 (range 1–13). The response rate was 33%. No toxicity was observed in 20% grade 3–4 toxicity in 10% (majority nausea/vomiting). The median progression‐free and overall survival times from starting pemetrexed were 184 days and 298 days, respectively. Conclusions: Pemetrexed‐based regimens are safe and effective in a community setting in malignant mesothelioma. 相似文献
5.
Dr. Barbara McGee Hughes Pharm.D. Dr. Ralph E. Small Pharm.D. Dr. Douglas Brink Pharm.D. Dr. Norma D. McKenzie M.D. 《Pharmacotherapy》1997,17(1):113-120
Study Objective . To evaluate the effects of flurbiprofen therapy on the pharmacokinetics of lithium. Design . Placebo-controlled, single-blind, crossover study. Setting . University-affiliated hospital. Patients . Eleven healthy women with bipolar disorder. Interventions . The subjects received therapeutic doses of lithium administered as an immediate-release capsule every 12 hours. In addition, they received one placebo tablet every 12 hours during phase I and flurbiprofen 100 mg every 12 hours during phase II of the study. Measurements and Main Results . Steady-state pharmacokinetic parameters were measured for each phase. Lithium trough plasma concentration (Cmin) and area under the curve were statistically significantly increased (p<0.05) when patients received flurbiprofen. Flurbiprofen also caused decreases in lithium clearance and 24-hour lithium urine excretion, although the changes did not reach statistical significance. Clinically significant increases in Cmin appeared to be associated with a greater than 1000-μg/24 hour decrease in urinary excretion of prostaglandin E2. Conclusion . Patients with clinically normal renal function may experience an increase in lithium levels with the initiation of flurbiprofen therapy. 相似文献
6.
CM Reid M. Nelson P. Beckinsale P. Ryan LMH Wing LJ Beilin MA Brown GLR Jennings CI Johnston J. Marley JJ McNeil TO Morgan J. Shaw ID Steven MJ West 《Clinical and experimental pharmacology & physiology》1997,24(5):370-373
1. The present study aimed to determine the feasibility of conducting a 5 year cardiovascular outcome trial of the treatment of 6000 elderly hypertensive patients in Australian general practices. 2. General practitioners (GPs) were invited to participate by mail and personal follow-up. Patient records were reviewed to identify subjects for a blood pressure (BP) screening programme. Blood pressure was measured on three occasions and eligible subjects were included if the average BP was 160 mmHg systolic or 90 mmHg diastolic if systolic BP was 140 mmHg. 3. Seven hundred and forty-one GPs were approached and 89 were enrolled in the study (12% of mail invites and 75% of those receiving a personal contact). In 16 practices where screening was completed, 82 000 records were reviewed to identify 4% patients eligible for screening. Twenty-two per cent of eligible subjects attended screening. Of 1938 subjects screened, 180 (9%) had BP 5=160/90 mmHg. Forty-seven percent of subjects (n = 916) were receiving antihypertensive therapy and 184 (20%) were withdrawn from therapy. One hundred and sixteen (63%) of these subjects had BP return to study entry levels within 6 weeks. Fifty-seven newly diagnosed and 81 previously treated subjects were randomized (7% of the screened population). 4. Based on the high participation rate of GPs, the response rate of patients to attend a BP screening programme and the 7% randomization to screening ratio for entry into the study, the ANBP2 pilot study has demonstrated that it is feasible to recruit subjects from Australian general practices to a cardiovascular outcome trial. 相似文献
7.
Benign intracranial hypertension and recombinant growth hormone therapy in Australia and New Zealand
PA Crock JD McKenzie AM Nicoll NJ Howard W Cutfield LK Shield G Byrne 《Acta paediatrica (Oslo, Norway : 1992)》1998,87(4):381-386
Benign intracranial hypertension (BIH) is reported in three children from Australia and one from New Zealand, who were being treated with recombinant human growth hormone (rhGH). Three males and one female, aged between 10.5 and 14.2 y, developed intracranial hypertension within 2 weeks to 3 months of starting treatment. A national database, OZGROW, has been prospectively collecting data on all 3332 children treated with rhGH in Australia and New Zealand from January 1986 to 1996. The incidence of BIH in children treated with growth hormone (GH) is small, 1.2 per 1000 cases overall, but appears to be greater with biochemical GHD (<10IUml -1 ), i.e. 6.5/1000 (3 in 465 cases), relative risk 18.4, 95% confidence interval 1.9-176.1, than in all other children on the database. The incidence in patients with Turner's syndrome was 2.3/1000 (1 in 428 cases). No cases in patients with partial GHD (10–20 IUml -1 ) or chronic renal failure were identified. Possible causative mechanisms are discussed. The authors'practice is now to start GH replacement at less than the usual recommended dose of 14IUm-2 week-1 in those children considered to be at high risk of developing BIH. Ophthalmological evaluation is recommended for children before and during the first few months following commencement of rhGH therapy and is mandatory in the event of peripheral or facial oedema, persistent headaches, vomiting or visual symptoms. The absence of papilledema does not exclude the diagnosis. 相似文献
8.
The risk of cytomegalovirus infection in seronegative transfusion recipients not receiving exogenous immunosuppression 总被引:3,自引:0,他引:3
We studied 637 transfusion recipients seronegative for cytomegalovirus (CMV) in the following categories: neonates; pregnant women; and patients experiencing trauma, burns, cardiovascular surgery (adult or pediatric), major surgery, or gastrointestinal hemorrhages. Cultures and serological tests were used to follow up subjects for evidence of CMV infection for a period of three months after their last transfusion. Six (0.9%) developed CMV infection. No significant differences in risk among patient categories were observed. Infected patients received a significantly larger mean number of units of cellular blood products (CBP; 50.0 +/- 38.9 vs. 6.2 +/- 8.5; P less than .001) and plasma (23.7 +/- 15.3 vs. 2.6 +/- 4.6, P less than .001) than did uninfected patients. This result represents a risk per unit of CBP transfused of 0.14%, or approximately 0.38% per unit of seropositive CBP transfused. We observed, however, that patients exposed to CBP from greater than 30 donors had a higher risk of acquiring CMV infection than would be predicted if infectious units were randomly distributed among all donors (P less than .01). 相似文献
9.
10.
I S Mashini L D Devoe J S McKenzie H A Hadi D M Sherline 《Obstetrics and gynecology》1987,69(1):74-78
Intermittent nipple stimulation has been proposed as a substitute for exogenous oxytocin infusion in the performance of contraction stress tests. To compare the uterine activity produced by these two methods, we studied a group of 45 term pregnant women undergoing indicated inductions of labor. Twenty-five patients had nipple stimulation and 20 patients received oxytocin infusions according to a study protocol. The two groups were similar in all obstetric parameters. Pre- and posttest uterine activity was measured by internal tocodynamometry and quantified in Montevideo units. A significant increase in uterine activity occurred in both groups (P less than .01). Regular uterine activity (three contractions in ten minutes) was achieved more rapidly (P less than .005), but at a lower level (P less than .001) in the nipple stimulation group. Pre- and posttest tonus did not change significantly in either group. In the nipple stimulation group, five patients (20%) did not achieve adequate contraction patterns after 15 stimulation-rest cycles (a total of 110 minutes) and three subjects (12%) experienced uterine hyperstimulation. These observations suggest that exogenous oxytocin and intermittent nipple stimulation may not have equivalent effects on uterine contractility. Therefore, it may not be justified to substitute one technique for the other or to use the same criteria for interpretation of contraction stress tests produced by both techniques. 相似文献