全文获取类型
收费全文 | 11525篇 |
免费 | 869篇 |
国内免费 | 33篇 |
专业分类
耳鼻咽喉 | 125篇 |
儿科学 | 282篇 |
妇产科学 | 227篇 |
基础医学 | 1182篇 |
口腔科学 | 244篇 |
临床医学 | 1311篇 |
内科学 | 2254篇 |
皮肤病学 | 99篇 |
神经病学 | 1031篇 |
特种医学 | 646篇 |
外科学 | 1817篇 |
综合类 | 208篇 |
一般理论 | 4篇 |
预防医学 | 1353篇 |
眼科学 | 226篇 |
药学 | 647篇 |
1篇 | |
中国医学 | 9篇 |
肿瘤学 | 761篇 |
出版年
2023年 | 73篇 |
2022年 | 136篇 |
2021年 | 302篇 |
2020年 | 142篇 |
2019年 | 236篇 |
2018年 | 299篇 |
2017年 | 200篇 |
2016年 | 195篇 |
2015年 | 250篇 |
2014年 | 313篇 |
2013年 | 438篇 |
2012年 | 664篇 |
2011年 | 640篇 |
2010年 | 305篇 |
2009年 | 300篇 |
2008年 | 529篇 |
2007年 | 549篇 |
2006年 | 472篇 |
2005年 | 484篇 |
2004年 | 477篇 |
2003年 | 393篇 |
2002年 | 348篇 |
2001年 | 310篇 |
2000年 | 350篇 |
1999年 | 276篇 |
1998年 | 101篇 |
1997年 | 66篇 |
1996年 | 90篇 |
1995年 | 74篇 |
1994年 | 91篇 |
1993年 | 79篇 |
1992年 | 230篇 |
1991年 | 221篇 |
1990年 | 236篇 |
1989年 | 221篇 |
1988年 | 214篇 |
1987年 | 193篇 |
1986年 | 192篇 |
1985年 | 148篇 |
1984年 | 139篇 |
1983年 | 125篇 |
1982年 | 83篇 |
1981年 | 64篇 |
1980年 | 70篇 |
1979年 | 110篇 |
1978年 | 110篇 |
1974年 | 80篇 |
1973年 | 78篇 |
1972年 | 71篇 |
1970年 | 67篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
Primary infiltrating signet ring carcinoma of the eyelids 总被引:1,自引:0,他引:1
F A Jakobiec P Austin T Iwamoto S L Trokel M D Marquardt W Harrison 《Ophthalmology》1983,90(3):291-299
A 61-year old man presented with a five-year history of a swelling initially developing in his right lower lid that progressed to involve the lateral canthal skin and eventually the upper lid and anterior orbit. He was discovered to have an infiltrating, poorly differentiated, mucin-producing carcinoma. Systemic work-up failed to disclose a visceral malignancy, and it was concluded that his tumor was primary in the lids, arising from an adnexal sweat gland. Three other reports in the literature also share almost identical clinical and pathologic features, in that all of the earlier reports dealt with middle-aged or elderly men who had diffusely indurated lids. Histopathologically, the tumor cells grow diffusely in a sclerotic stroma, and resemble the "histiocytoid" variant of metastatic breast carcinoma to the lids in women. Ultrastructural studies in our case point toward an apocrine origin, although earlier authors have favored an eccrine origin. Despite its indolent clinical course, the tumor is capable of producing regional and distant metastases on long-term follow-up. Complete local excision, possibly necessitating radical surgery, is probably the preferred method of treatment, but local radiotherapy may have a beneficial effect in retarding spread of the disease. 相似文献
83.
The variation in plasma albumin concentrations of rats fed a wide range of protein- and energy-deficient diets has been investigated. These changes have been correlated with simultaneous effects of the diets on growth rate, carcass composition, protein and energy balance, and plasma concentration of insulin corticosterone and triiodothyronine (T3). Although rats eating diets of low protein content and libitum developed hypoalbuminemia, those fed equivalent amounts of protein at low energy intakes had plasma albumin concentrations nearer, or equal to control values. Data from the balance study showed that for hypoalbuminemia to occur, not only had dietary protein to be inadequate, it was also necessary for energy consumption to be in excess of requirements. It is suggested that in protein-deficient animals, energy consumed in excess of the amount required for maintenance and the protein-limited growth rate initiates a metabolic response which results in inappropriate use of the meagre protein intake. This "dysadapted" state, in the rat, appears to be indicated by elevated plasma T3 values. The implication that kwashiorkor-like symptoms can be generated by a relative as opposed to a total energy excess is discussed in relation to the appearance of this disease in humans. 相似文献
84.
H Preisler A Raza R Larson J Goldberg G Tricot M Carey C Kukla 《Leukemia research》1991,15(9):773-780
The failure of three consecutive treatment protocols to significantly increase the complete remission rate for poor prognosis newly diagnosed patients with acute myelocytic leukemia led to a detailed investigation of the causes of treatment failure. In the majority of cases treatment failure was attributable to "clinical resistance" to therapy. Upon close examination two types of "clinical resistance" were discernible: the failure of chemotherapy to produce adequate cytotoxic effects ("classical" drug resistance), and treatment failure attributed to the rapid regrowth of leukemia cells subsequent to the substantial killing of leukemia cells by cytotoxic therapy ("biological" resistance). Each form of resistance accounted for one-half of the treatment failures. 相似文献
85.
S M Larson J A Carrasquillo D C Colcher K Yokoyama J C Reynolds S A Bacharach A Raubitchek L Pace R D Finn M Rotman 《Journal of nuclear medicine》1991,32(9):1661-1667
Using a newly available model for determining estimates of radiation absorbed dose of radioisotopes administered intraperitoneally, we have calculated absorbed dose to tumor and normal tissues based on a surgically controlled study of radiolabeled antibody distribution. Ten patients with peritoneal carcinomatosis received intraperitoneal injections of the murine monoclonal antibody B72.3 radiolabeled with 131I. Biodistribution studies were performed using nuclear medicine methods until laparotomy at 4-14 days after injection. Surgical biopsies of normal tissues and tumor were obtained. The marrow was predicted to be the critical organ, with maximum tolerated dose [200 rad (2 Gy) to marrow] expected at about 200 mCi (7.4 GBq). In patients with large intraperitoneal tumor deposits, the tumor itself is an important source tissue for radiation exposure to normal tissues. Local "hot-spots" for tumor-absorbed dose were observed, with maximum tumor-absorbed dose calculated at 11,000 rad (11 Gy) per 100 mCi (3.7 GBq) administered intraperitoneal; however, tumor rad dose varied considerably. This may pose serious problems for curative therapy, especially in patients with large tumor burdens. 相似文献
86.
Methods of controlling controlled substance (CS) inventories in unit dose dispensing systems vary. The two extremes are total floor stock of all CS drugs by the use of declining inventory signout sheets on the nursing unit to controlling only Class II and a few selected class III-V items. The method described herein outlines a systematic approach to controlling items on an individual patient basis consistant with the benefits of unit dose dispensing. A CS card assigned to each patient for each of his required controlled substance medications serves as an audit trail for doses consumed by the patient and provides a declining inventory receipt when returned to the pharmacy. 相似文献
87.
T E Davis L Kahan D C Tormey F C Larson S A Anderson J J Crowley R N Carey 《Cancer research》1981,41(3):1110-1113
The activity of an isoenzyme of alkaline phosphatase (FHAP) was measured in serum samples obtained from 1692 individual subjects. The median FHAP concentration in patients with untreated or recurrent cancer (2.73 IU/liter) was two-fold higher than in hospitalized control patients with illnesses other than cancer (1.17 IU/liter) and three-fold higher than in healthy control subjects (0.93 IU/liter). Among patients with either breast or colorectal cancer who were clinically disease free following their initial therapy, the median FHAP concentration (1.54 IU/liter) was intermediate between the median FHAP concentration in patients with untreated or recurrent cancer and that of healthy control subjects. In order to illustrate the potential clinical application of FHAP as a diagnostic cancer marker, we have selected a serum FHAP concentration of 2.22 IU/liter as a reference value above which only 3% of healthy control subjects would have a "positive" test. Utilizing this reference value, 58% of the patients in the present study with untreated or recurrent cancer would have a positive FHAP test, whereas only 11%, of hospitalized patients with illnesses other than cancer would have a positive test. These data suggest that FHAP may be equivalent to the carcinoembryonic antigen as a diagnostic cancer marker. 相似文献
88.
M S Larson 《Int J Health Serv》1979,9(4):607-627
Historically, the early professionalization movements in medicine and the law appear as organizational projects which aspire to monopolize income and opportunities in markets of services or labor and to monopolize status and work privileges in occupational hierarchies. Their central task is to standardize training and link it to actual or potential markets of labor or services, a linkage that is structurally effected in the modern university. The second wave of professionalization has different protagonists than the older "market professions": placed in a different structural situation, the bureaucratic professions transform the model of profession (which they adopt as a strategy of collective ascension) into an ideology. The import of the ideology of professionalism is examined in relation to two issues: the relationships between professional occupations and bureaucratic organizations; and the position of professional occupations within the larger structure of inequality. Analysis of the first point requires consideration of the distinctions between professional occupations in the public and private sectors, the use of professional knowledge and the image of profession in bureaucratic organizations, and the specific characteristics of professions that produce their own knowledge. In the discussion of the second point, professional occupations and their ideology are examined in relation to other occupations and to the possibilities of political awareness generated by uncertain professional statuses. 相似文献
89.
90.
Holroyd-Leduc JM Kapral MK Austin PC Tu JV 《Stroke; a journal of cerebral circulation》2000,31(8):1833-1837
BACKGROUND AND PURPOSE: Previous studies have documented sex differences in the management and outcome of patients with cardiovascular disease. However, little data exist on whether similar sex differences exist in stroke patients. We conducted a study to determine whether sex differences exist in patients with acute stroke admitted to Ontario hospitals. METHODS: Using linked administrative databases, we performed a population-based cohort study. The databases contained information on all 44 832 patients discharged from acute-care hospitals in Ontario between April 1993 and March 1996 with a most responsible diagnosis of acute stroke. The main outcomes measured consisted of sex differences in comorbidities, the use of rehabilitative services, the use of antiplatelet therapy and anticoagulants (in elderly stroke survivors aged > or =65 years only), discharge destination, and mortality. RESULTS: Male stroke patients were more likely than female stroke patients to have a history of ischemic heart disease (18.1% versus 15.3%, respectively; P<0.001) and diabetes mellitus (20.1% versus 18. 7%, respectively; P<0.001), whereas female patients were more likely than male patients to have hypertension (33.8% versus 30.0%, respectively; P<0.001) and atrial fibrillation (12.9% versus 10.2%, respectively; P<0.001). There were no sex differences in the usage of in-hospital rehabilitative services. The overall 90-day postdischarge use of aspirin and ticlopidine was similar in stroke survivors aged 65 to 84 years. However, among stroke survivors aged > or =85 years, men were more likely than women to receive aspirin (36. 0% versus 30.7%, respectively; P<0.001) and ticlopidine (9.2% versus 6.8%, respectively; P=0.007). Use of warfarin was similar for the two sexes. Men were more likely than women to be discharged home (50. 6% versus 40.9%, respectively; P<0.001) and less likely to be discharged to chronic care facilities (16.8% versus 25.2%, respectively; P<0.001). The risk of death 1 year after stroke was somewhat lower in women than men (adjusted odds ratio 0.939, 95% CI 0.899 to 0.980; P=0.004). The mortality differences were greatest among elderly stroke patients. CONCLUSIONS: Elderly men are more likely than elderly women to receive aspirin and ticlopidine and equally like to receive warfarin after a stroke. Despite these differences, elderly women have a better 1-year survival after a stroke. 相似文献