全文获取类型
收费全文 | 1986333篇 |
免费 | 143179篇 |
国内免费 | 3673篇 |
专业分类
耳鼻咽喉 | 26901篇 |
儿科学 | 64127篇 |
妇产科学 | 56131篇 |
基础医学 | 289897篇 |
口腔科学 | 55471篇 |
临床医学 | 178307篇 |
内科学 | 390627篇 |
皮肤病学 | 42638篇 |
神经病学 | 158838篇 |
特种医学 | 76383篇 |
外国民族医学 | 584篇 |
外科学 | 293735篇 |
综合类 | 41893篇 |
现状与发展 | 3篇 |
一般理论 | 788篇 |
预防医学 | 157093篇 |
眼科学 | 45216篇 |
药学 | 144058篇 |
7篇 | |
中国医学 | 3568篇 |
肿瘤学 | 106920篇 |
出版年
2018年 | 20575篇 |
2016年 | 17353篇 |
2015年 | 19930篇 |
2014年 | 27878篇 |
2013年 | 42888篇 |
2012年 | 57972篇 |
2011年 | 61792篇 |
2010年 | 36529篇 |
2009年 | 34837篇 |
2008年 | 58584篇 |
2007年 | 62427篇 |
2006年 | 62199篇 |
2005年 | 61083篇 |
2004年 | 58666篇 |
2003年 | 56396篇 |
2002年 | 54949篇 |
2001年 | 87565篇 |
2000年 | 89574篇 |
1999年 | 76013篇 |
1998年 | 21388篇 |
1997年 | 19478篇 |
1996年 | 19857篇 |
1995年 | 18576篇 |
1994年 | 17517篇 |
1993年 | 16448篇 |
1992年 | 60318篇 |
1991年 | 58817篇 |
1990年 | 57420篇 |
1989年 | 55372篇 |
1988年 | 51453篇 |
1987年 | 50399篇 |
1986年 | 48254篇 |
1985年 | 45763篇 |
1984年 | 34631篇 |
1983年 | 29897篇 |
1982年 | 17947篇 |
1981年 | 16089篇 |
1979年 | 32885篇 |
1978年 | 23705篇 |
1977年 | 19956篇 |
1976年 | 18585篇 |
1975年 | 20276篇 |
1974年 | 24467篇 |
1973年 | 23837篇 |
1972年 | 22538篇 |
1971年 | 20926篇 |
1970年 | 19918篇 |
1969年 | 18800篇 |
1968年 | 17678篇 |
1967年 | 16010篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
APACHE II score and abdominal sepsis. A prospective study 总被引:7,自引:0,他引:7
J M Bohnen R A Mustard S E Oxholm B D Schouten 《Archives of surgery (Chicago, Ill. : 1960)》1988,123(2):225-229
Therapeutic trials for intra-abdominal sepsis require pretreatment stratification; physiologic scoring has been recently proposed for this purpose. We have prospectively tested the validity of one such scoring system, namely, the Acute Physiology and Chronic Health Evaluation (APACHE II). As part of a larger database, we correlated APACHE II scores with mortality in 100 patients hospitalized for generalized peritonitis or abdominal abscess. Use of steroids was recorded because of our suspicion that steroids increase mortality but blunt the physiologic response to sepsis. Thirty-one patients died, including 12 of 19 patients receiving steroids. Stepwise discriminant analysis revealed that the APACHE II score and steroid use were each independently associated with the rate of mortality. We report a prospective validation of pretreatment APACHE II scoring in abdominal sepsis. Steroid use is an independent risk factor. 相似文献
142.
Edward R. Westrick MS Allan P. Shapiro PhD Peter E. Nathan PhD John Brick PhD 《Alcoholism, clinical and experimental research》1988,12(4):531-533
The present study demonstrates that alcohol-induced memory impairment can be attenuated by pretreatment with an oral tryptophan supplementation. These results provide support for the role of a brain serotonin deficit in this impairment and highlight the impact a dietary manipulation can have on a complex behavioral process. 相似文献
143.
A novel hybridoma antibody (PASE/4LJ) to human prostatic acid phosphatase suitable for immunohistochemistry 总被引:2,自引:0,他引:2
A M Haines S E Larkin A P Richardson R W Stirling E Heyderman 《British journal of cancer》1989,60(6):887-892
A murine monoclonal antibody PASE/4LJ to prostatic acid phosphatase (PAP) was used to immunostain a wide variety of sections of benign and malignant tissues (654 blocks). Non-neoplastic adult and fetal prostatic glands, primary and metastatic prostatic carcinomas, and scattered cells in prostatic and penile urethra were positive. Rat, dog and rabbit prostates were negative. Nine of 400 tumours of non-prostatic origin showed some positivity: 6/36 carcinoids, 1/9 islet cell tumours, 1/55 ovarian adenocarcinomas (serous) and one carcinosarcoma of the lung (epithelial portion). Positive staining was seen in islet cells in 4/5 specimens of normal pancreas, and in 4/9 blocks of normal pancreas surrounding a pancreatic tumour. Loops of Henle, maculae densae, and distal tubules in 10/10 fetal and 2/9 adult kidneys were also positive, with proximal tubules and collecting ducts negative. All other 159 blocks of non-neoplastic adult and fetal tissues were negative. The antibody was also affinity purified from ascitic fluid, and shown not to inhibit the enzyme activity of prostatic acid phosphatase. 相似文献
144.
R Rosso F Boccardo F Brema M R Sertoli D Amoroso G Bertelli P Pronzato 《Anticancer research》1989,9(4):1153-1156
131 patients with resectable, node-positive breast cancer were treated at the National Institute for Cancer Research of Genoa, Italy with a systemic adjuvant regimen based on 14 cycles of chemotherapy, immunostimulation with levamisole, and--for postmenopausal patients--hormone therapy with tamoxifen. The present evaluation is performed eleven years after the admission of the first patient: so far, 75 patients (57.3%) have relapsed and 52 (39.7%) have died. An analysis of prognostic factors for relapse and death shows that the number of positive axillary lymph nodes and the dimension of the primary tumor are significantly associated with survival and relapse-free survival, while age and menopausal status are not. 相似文献
145.
146.
B. Ehlers E. Strauch M. Goltz D. Kubsch H. Wagner H. Maidhof J. Bendiek B. Appel H. -J. Buhk 《Bundesgesundheitsblatt, Gesundheitsforschung, Gesundheitsschutz》1997,40(4):118-121
Zusammenfassung Ein PCR-Nachweis für gentechnisch ver?nderten Mais ?Event 176? der Fa. Ciba-Geigy wurde etabliert. Der Mais enth?lt Gene,
die Selbstschutz gegen den Maiszünsler (Delta-Endotoxin-Gen ausBacillus thuringiensis) und Toleranz gegen das Herbizid Basta (Phosphinothricin-Resistenz-Gen ausStreptomyces hygroscopicus) vermitteln. Zudem enth?lt der Mais ein Ampicillin-Resistenz-Gen. Für die Amplifikation von Bereichen aus allen drei Genen
wurden PCR-Primer entworfen. Mit Hilfe dieser Primer und mit ?Event 176?-Mais-DNA als Template konnten die entsprechenden
Genbereiche in der PCR amplifiziert werden. Die PCR-Produkte wurden sequenziert, um ihre Identit?t zu best?tigen. Mit Hilfe
der Delta-Endotoxin-PCR wurden, auch in Gegenwart von 104fachem überschu? nicht gentechnisch ver?nderter Mais-DNA, fünf haploide Genome der ?Event 176?-DNA nachgewiesen.
Identification of genetically modified maize by PCR
Summary A PCR-test for the genetically modified maize ?Event 176? of Ciba-Geigy was established. The maize contains genes conferring resistance to the European corn borer (delta-endotoxin gene fromBacillus thuringiensis) and tolerance to the herbicide Basta (phosphinothricin resistance gene fromStreptomyces hygroscopicus). The maize contains also an ampicillin resistance gene. Primers were designed and using ?Event 176?-maize-DNA as template internal regions of the three genes were amplified with PCR. The PCR products were sequenced to confirm their identity. Using the deltaendotoxin primers in PCR down to 5 haploid genomes of ?Event 176?-DNA could be detected, even in the presence of a 104fold excess of DNA from non-modified maize.相似文献
147.
P. THOMPSON F. INGLIS D. FINDLAY J. GILCHRIST M. E. T. MCMURDO 《Aging & mental health》1997,1(2):181-183
The Dundee Memory Clinic was established in 1991. This paper reviews the diagnosis of the first 150 attenders and compares the findings with those of other memory clinics. 相似文献
148.
149.
Elaina F. George Arnold Komisar Stephen C. Scharf Adrienne Ferracci Stanley Blaugrund 《The Laryngoscope》1998,108(5):627-629
A retrospective chart review of 43 patients who underwent technetium 99m (Tc-99m) sestamibi scans from June 1995 to January 1997 was performed. Only those who underwent subsequent parathyroid exploration with excision were included in the study. Twenty subjects (13 women and seven men) were included in the study. Ages ranged from 21 to 84 years (mean, 58 years). All patients had laboratory values and clinical findings consistent with primary hyperparathyroidism. Two patients had preoperative magnetic resonance imaging (MRI) scans (one patient with recurrent disease), and one had a preoperative computed tomography (CT) scan. The remaining patients had the sestamibi scan as the only preoperative localization study. There were 18 pathologic diagnoses of parathyroid adenoma and two of parathyroid hyperplasia. Sestamibi failed to correctly identify the location of the parathyroid lesion in two cases. In 18 cases the preoperative sestamibi scan correctly localized the lesion, a predictive value of 90%. We conclude that the Tc-99m sestamibi scan is an accurate preoperative tool that can be used as a single modality to localize parathyroid adenomas. 相似文献
150.
This study examines the relationships between patient characteristics and surrogate decision maker characteristics on surrogates' preferences for life-sustaining treatments. Caucasian and African-American caregivers and noncaregivers (n=110) responded to a vignette involving a medical crisis in a hospitalized older man who suffered cardiac arrest, one of the most common causes of death among older Americans. This man was described as either a cognitively intact or moderately demented family member. Participants made decisions regarding cardiopulmonary resuscitation (CPR), CPR and ventilation, and CPR and tube feeding. Analyses followed a 2 (cognitive status) 2 (caregiving status) 2 (racial background) analysis of covariance design, with education and income used as covariates. In general, participants were less likely to initiate life-sustaining treatments in demented patients. Caucasian caregivers were less likely to initiate CPR and ventilation and CPR and tube feeding. Results indicate that characteristics of the patient and the interplay between cultural issues and experience with caregiving affect surrogate judgements regarding life-sustaining treatments. 相似文献