全文获取类型
收费全文 | 8195篇 |
免费 | 918篇 |
国内免费 | 169篇 |
专业分类
耳鼻咽喉 | 82篇 |
儿科学 | 319篇 |
妇产科学 | 189篇 |
基础医学 | 477篇 |
口腔科学 | 140篇 |
临床医学 | 1711篇 |
内科学 | 1774篇 |
皮肤病学 | 150篇 |
神经病学 | 488篇 |
特种医学 | 252篇 |
外科学 | 1886篇 |
综合类 | 52篇 |
一般理论 | 1篇 |
预防医学 | 692篇 |
眼科学 | 366篇 |
药学 | 305篇 |
中国医学 | 3篇 |
肿瘤学 | 395篇 |
出版年
2023年 | 118篇 |
2021年 | 95篇 |
2020年 | 126篇 |
2019年 | 98篇 |
2018年 | 190篇 |
2017年 | 218篇 |
2016年 | 235篇 |
2015年 | 200篇 |
2014年 | 292篇 |
2013年 | 402篇 |
2012年 | 237篇 |
2011年 | 266篇 |
2010年 | 295篇 |
2009年 | 419篇 |
2008年 | 253篇 |
2007年 | 207篇 |
2006年 | 247篇 |
2005年 | 230篇 |
2004年 | 151篇 |
2003年 | 184篇 |
2002年 | 157篇 |
2001年 | 205篇 |
2000年 | 150篇 |
1999年 | 206篇 |
1998年 | 213篇 |
1997年 | 232篇 |
1996年 | 337篇 |
1995年 | 284篇 |
1994年 | 216篇 |
1993年 | 131篇 |
1992年 | 173篇 |
1991年 | 183篇 |
1990年 | 105篇 |
1989年 | 171篇 |
1988年 | 146篇 |
1987年 | 118篇 |
1986年 | 147篇 |
1985年 | 124篇 |
1984年 | 116篇 |
1983年 | 99篇 |
1982年 | 86篇 |
1981年 | 75篇 |
1980年 | 91篇 |
1979年 | 65篇 |
1978年 | 77篇 |
1977年 | 62篇 |
1976年 | 65篇 |
1975年 | 71篇 |
1964年 | 53篇 |
1963年 | 52篇 |
排序方式: 共有9282条查询结果,搜索用时 250 毫秒
111.
M Barringer G V Poole Jr A C Shircliffe J W Meredith F Hightower G W Plonk Jr 《Annals of surgery》1983,197(2):204-209
An inexpensive femoral "cuff" developed in this noninvasive vascular laboratory allows pulse volume recordings and systolic pressure measurements of the femoral arteries. Using the parameters 1) femoral/brachial systolic pressure ratio, 2) wave amplitude, and 3) status of the dicrotic notch for assessment of results, it was found that the cuff correctly identified 59 of 62 limbs with at least 50% aortoiliac stenosis, with only two false-positive results, for an accuracy of 97%. The high, wide thigh cuff identified 57 of the 62 limbs, but had 45 false-positive results (77% accuracy). Use of the femoral "cuff" has refined the ability to identify the anatomic location of significant arterial stenoses in the lower extremities. 相似文献
112.
The success of vertical gastroplasty may be jeopardized by gastric leakage or ulceration due to failure of the technique.
Reports of band erosion and staple-line leakage have led us to seek technical improvements to reduce technical failures. We
describe a modification to the technique of band placement and a manoeuvre to aid the placement of staples when the TA90 staple
gun is used. 相似文献
113.
Richard I. Hall J. Thomas Murphy Emerson A. Moffitt Roderick Landymore P. Timothy Pollak Laurie Poole 《Journal canadien d'anesthésie》1991,38(8):996-1004
The purpose of this study was to compare propofol-sufentanil with enflurane-sufentanil anaesthesia for patients undergoing elective coronary artery bypass graft (CABG) surgery with respect to changes in (1) haemodynamic variables; (2) myocardial blood flow and metabolism; (3) serum cortisol, triglyceride, lipoprotein concentrations and liver function; and (4) recovery characteristics. Forty-seven patients with preserved ventricular function (ejection fraction greater than 40%, left ventricular end diastolic pressure less than or equal to 16 mmHg) were studied. Patients in Group A (n = 24) received sufentanil 0.2 microgram.kg-1 and propofol 1-2 mg.kg-1 for induction of anaesthesia which was maintained with a variable rate propofol (50-200 micrograms.kg-1.min-1) infusion and supplemental sufentanil (maximum total 5 micrograms.kg-1). Patients in Group B (n = 23) received sufentanil 5 micrograms.kg-1 for induction of anaesthesia which was maintained with enflurane and supplemental sufentanil (maximum total 7 micrograms.kg-1). Haemodynamic and myocardial metabolic profiles were determined at the awake-sedated, post-induction, post-intubation, first skin incision, post-sternotomy, and pre-cardiopulmonary bypass intervals. Induction of anaesthesia produced a larger reduction in systolic blood pressure in Group A (156 +/- 22 to 104 +/- 20 mmHg vs 152 +/- 26 to 124 +/- 24 mmHg; P less than 0.05). No statistical differences were detected at any other time or in any other variable including myocardial lactate production (n = 13 events in each group), time to tracheal extubation and time to discharge from the ICU. We concluded that, apart from hypotension on induction of anaesthesia, propofol-sufentanil anaesthesia produced anaesthetic conditions equivalent to enflurane-sufentanil anaesthesia for CABG surgery. 相似文献
114.
Frydenberg HB 《Obesity surgery》1991,1(3):315-317
Many forms of gastric banding have been described and high reoperation rates reported. These can be mainly attributed to excess
vomiting associated both with and without stenosis. Reflux oesophagitis and the ‘sump’ effect may be other causes. This paper
examines the problems associated with banding leading to revisional surgery and introduces a new technique, ‘fundal supporting
suture’, to correct these problems. Preliminary results on 126 bandings without the modification and 22 with the modification
are presented. 相似文献
115.
Eighty-four pediatric patients were evaluated clinically and radiographically on 112 separate admissions for suspected increased intracranial pressure and possible shunt malfunction. The shunt system was tested clinically in each patient and correlated with the ventricular size as determined by CT. Of the patients with enlarged ventricles, 87% had an improperly functioning shunt and 13% had a normally functioning shunt. Of the patients with normal or small ventricles, 93% had a normally functioning shunt. Thus the "false negative" rate was 4% (small ventricles with a nonfunctioning shunt) and the "false positive" rate was 13% (large ventricles with a functioning shunt). 相似文献
116.
Increased placental apoptosis in intrauterine growth restriction 总被引:2,自引:0,他引:2
Stephen C. Smith MB ChB Philip N. Baker DM E.Malcolm Symonds MD 《American journal of obstetrics and gynecology》1997,177(6):1395-1401
OBJECTIVES: Our purpose was to investigate a possible role for apoptosis in the pathophysiologic mechanisms of intrauterine growth restriction. STUDY DESIGN: Placental samples were obtained from 43 uncomplicated third-trimester pregnancies and from 26 pregnancies complicated by intrauterine growth restriction. The definition used to identify cases of intrauterine growth restriction depended on three criteria: clinical evidence of suboptimal growth, ultrasonographic evidence of deviation from an appropriate growth percentile, and individualized birth weight ratios <10th percentile. Light microscopy was used to quantify the incidence of apoptosis. Electron microscopy and TUNEL (terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick end labeling) staining were used to confirm the occurrence of apoptosis. RESULTS: Quantification of apoptosis (medians and interquartile ranges) resulted in the following values: normal third trimester (n = 43) 0.14% of cells (0.08% to 0.20%) and intrauterine growth restriction third trimester (n = 26) 0.24% of cells (0.16% to 0.29%). The incidence of apoptosis was significantly higher in placentas from pregnancies with intrauterine growth restriction compared with normal third-trimester placentas (p < 0.01, Mann Whitney U test). CONCLUSIONS: These results suggest that apoptosis may play a role in the pathophysiologic mechanisms of intrauterine growth restriction.(Am J Obstet Gynecol 1997;177:401) 相似文献
117.
MB Popli N Mehta VS Nijhavan V Popli 《Journal of Medical Imaging and Radiation Oncology》1998,42(3):256-257
Congenital tuberculosis is a rare disease. The non-specific nature of presenting signs and symptoms (because of the lack of host response) and the fatal outcome in the absence of early therapy all underscore the importance of early diagnosis and treatment in infants. Recognition requires awareness that tuberculosis at this age has manifestations not found in older children. Here a case of congenital tuberculosis is presented, where changes were confined only to the thorax. Tuberculosis in the mother could be diagnosed only retrospectively. 相似文献
118.
Murray DR Carlson GW Greenlee R Alazraki N Fry-Spray C Hestley A Poole R Blais M Timbert DS Vansant J 《The American surgeon》2000,66(8):763-767
Sentinel lymph node (SLN) biopsy is revolutionizing the surgical management of primary malignant melanoma. It allows accurate nodal staging which targets patients who may benefit from regional lymphadenectomy and systemic therapy. This is a retrospective review of patients treated at Emory University for stage I and II malignant melanoma with gamma probe-guided SLN biopsy from 1/1/94 to 6/30/98. Three hundred sixty patients (males 228, females 132) were identified. Primary melanoma sites included: head and neck 58, trunk 148, and extremities 154 (upper 71, lower 83). Primary tumor staging was T1 9, T2 134, T3 153, and T4 64. SLNs were successfully identified in 99.7 per cent of patients and 98.9 per cent of nodal basins mapped. In 275 (76.6%) cases a single draining nodal basin was identified. In 84 (23.3%) cases there were multiple draining nodal basins. Positive SLNs were identified in 63 patients (17.5%). SLN positivity by tumor staging was T1 0 per cent, T2 9.0 per cent, T3 22.2 per cent, and T4 26.6 per cent. The overall recurrence rate was 11.9 per cent. Recurrences by SLN status were SLN+, 27 per cent, and SLN-, 8.8 per cent. Regional recurrence occurred in 7 (2.4%) of the 297 with negative SLN biopsies and 7 (11.1%) of the 63 with positive SLN biopsies. Dynamic lymphoscintigraphy and gamma probe-guided SLN localization was successful in more than 98 per cent of cases. Patients with negative SLN biopsies have a low risk of recurrence. 相似文献
119.
120.
Graham G Dark A Hilary Calvert Robert Grimshaw Christopher Poole Ken Swenerton Stan Kaye Robert Coleman Gordon Jayson Tien Le Susan Ellard Marc Trudeau Paul Vasey Marta Hamilton Terri Cameron Emma Barrett Wendy Walsh Lynn McIntosh Elizabeth A Eisenhauer 《Journal of clinical oncology》2005,23(9):1859-1866
PURPOSE: Liposomal lurtotecan (OSI-211) is a liposomal formulation of the water-soluble topoisomerase I inhibitor lurtotecan (GI147211), which demonstrated superior levels of activity compared with topotecan in preclinical models. We studied two schedules of OSI-211 in a randomized design in relapsed ovarian cancer to identify the more promising of the two schedules for further study. PATIENTS AND METHODS: Eligible patients had measurable epithelial ovarian, fallopian, or primary peritoneal cancer that was recurrent after one or two prior regimens of chemotherapy. Patients were randomly assigned to receive either arm A (OSI-211 1.8 mg/m(2)/d administered by 30-minute intravenous infusion on days 1, 2, and 3 every 3 weeks) or arm B (OSI-211 2.4 mg/m(2)/d administered by 30-minute intravenous infusion on days 1 and 8 every 3 weeks). The primary outcome measure was objective response, which was confirmed by independent radiologic review, and a pick the winner statistical design was used to identify the schedule most likely to be superior. RESULTS: Eighty-one patients were randomized between October 2000 and September 2001. The hematologic toxic effects were greater on arm A than on arm B (grade 4 neutropenia, 51% v 22%, respectively), as was febrile neutropenia (26% v 2.4%, respectively). Of the 80 eligible patients, eight patients (10%) had objective responses; six responders (15.4%; 95% CI, 6% to 30%) were in arm A and two responders (4.9%; 95% CI, 1% to 17%) were in arm B. CONCLUSION: The OSI-211 daily for 3 days intravenous schedule met the statistical criteria to be declared the winner in terms of objective response. This schedule was also associated with more myelosuppression than the schedule of OSI-211 administered in arm B. 相似文献