全文获取类型
收费全文 | 8589篇 |
免费 | 704篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 112篇 |
儿科学 | 327篇 |
妇产科学 | 318篇 |
基础医学 | 1087篇 |
口腔科学 | 263篇 |
临床医学 | 873篇 |
内科学 | 1532篇 |
皮肤病学 | 261篇 |
神经病学 | 721篇 |
特种医学 | 480篇 |
外科学 | 1118篇 |
综合类 | 216篇 |
一般理论 | 7篇 |
预防医学 | 766篇 |
眼科学 | 72篇 |
药学 | 591篇 |
中国医学 | 13篇 |
肿瘤学 | 566篇 |
出版年
2021年 | 116篇 |
2020年 | 63篇 |
2019年 | 103篇 |
2018年 | 119篇 |
2017年 | 89篇 |
2016年 | 88篇 |
2015年 | 134篇 |
2014年 | 175篇 |
2013年 | 289篇 |
2012年 | 346篇 |
2011年 | 356篇 |
2010年 | 212篇 |
2009年 | 185篇 |
2008年 | 326篇 |
2007年 | 366篇 |
2006年 | 325篇 |
2005年 | 349篇 |
2004年 | 329篇 |
2003年 | 336篇 |
2002年 | 300篇 |
2001年 | 291篇 |
2000年 | 303篇 |
1999年 | 246篇 |
1998年 | 112篇 |
1997年 | 108篇 |
1996年 | 101篇 |
1995年 | 100篇 |
1994年 | 90篇 |
1993年 | 64篇 |
1992年 | 190篇 |
1991年 | 217篇 |
1990年 | 209篇 |
1989年 | 188篇 |
1988年 | 197篇 |
1987年 | 211篇 |
1986年 | 205篇 |
1985年 | 182篇 |
1984年 | 154篇 |
1983年 | 119篇 |
1982年 | 91篇 |
1981年 | 84篇 |
1980年 | 81篇 |
1979年 | 111篇 |
1978年 | 84篇 |
1977年 | 67篇 |
1976年 | 74篇 |
1974年 | 78篇 |
1973年 | 91篇 |
1972年 | 74篇 |
1970年 | 78篇 |
排序方式: 共有9323条查询结果,搜索用时 31 毫秒
1.
R. Foley P. Kelly S. Gatault F. Powell 《Journal of the European Academy of Dermatology and Venereology》2021,35(1):62-72
Demodex mites are microscopic arachnids found in the normal skin of many mammals. In humans, it is well established that Demodex mite density is higher in patients with the skin condition rosacea, and treatment with acaricidal agents is effective in resolving symptoms. However, pathophysiology of rosacea is complex and multifactorial. In dogs, demodicosis is a significant veterinary issue, particularly the generalized form of the disease which can be fatal if untreated. In each species, clinical and molecular studies have shown that the host’s immunological interactions with Demodex mites are an important, but not fully understood, aspect of how Demodex can live in the skin either as a harmless commensal organism or as a pathogenic agent. This review outlines the role of Demodex mites in humans and dogs, considering morphology, prevalence, symptoms, diagnosis, histology treatment and pathogenesis. 相似文献
2.
J M Powell 《Clinical orthopaedics and related research》1988,(230):266-272
The skeletal manifestations of malignant carcinoid seem not to have been reported in the orthopedic literature. Bronchial and hindgut carcinoid tumors are less numerous than midgut tumors but metastasize to bone much more frequently. Carcinoid skeletal deposits are usually osteoblastic and most commonly affect the axial skeleton. The radiologic appearance is frequently indistinguishable from prostatic skeletal metastases or chronic sclerosing osteomyelitis. Two cases of skeletal metastases from midgut carcinoid are reported to demonstrate that metastases from carcinoid should be considered in the differential diagnosis of either bone malignancy or chronic sclerosing osteomyelitis. 相似文献
3.
Phase I study of high-dose cytosine arabinoside and etoposide in patients with advanced malignancies
Bayard L. Powell Hyman B. Muss Robert L. Capizzi Mary E. Caponera Douglas R. White Patricia J. Zekan James N. Atkins Don V. Jackson Jr. Frederick Richards II John B. Craig Julia M. Cruz Charles L. Spurr 《Cancer chemotherapy and pharmacology》1987,19(3):250-252
Summary Cytosine arabinsodie (ara-C) and etoposide (VP-16) display synergy in the laboratory. Twenty-six patients participated in a phase I study of high-dose ara-C in combination with VP-16. The dose of VP-16 was held constant at 50 mg/m2 as an intermittent infusion over 33 h; escalating doses of ara-C were given as infusions during hours 9–12 and 21–24. Myelosuppression was the dose-limiting toxicity and occurred with doses considerably less than those expected from studies of the two drugs as single agents. The suggested initial doses for phase II trials with this schedule are 750 mg/m2×2 doses of ara-C and 50 mg/m2 of VP-16. Nonhematologic toxicity was minimal; therefore, further dose escalation is feasible in patients in whom myelosuppression is acceptable.Supported in part by grants from the National Cancer Institute (CA-12197 and CA-09422) and the American Cancer Society CF-85-182 相似文献
4.
5.
Janet M Powell Sonya L Griffith Elizabeth M Kanny 《The American journal of occupational therapy》2005,59(4):467-474
PURPOSE: To provide a model for assessing occupational therapy workforce needs by using a demand-based approach to determine current workforce status in the Northwest region. Regional information may have implications for addressing national occupational therapy service needs. METHOD: A questionnaire was sent to a proportional random sample of 234 facilities that hire occupational therapy practitioners. Data were collected in July-August 2003 using structured mailing and follow-up procedures. RESULTS: Response rate was 79%. Twenty-four percent reported occupational therapy vacancies and 11% occupational therapy assistant vacancies; 48% predicted an increase in occupational therapy positions in the next 2 years and 41% an increase in occupational therapy assistant positions. Sixty-three percent of respondents reported difficulty in hiring. DISCUSSION: This study identifies an occupational therapy workforce shortage in the Northwest. Management of a shortage is critical, for even short-term adjustments could lead to permanent changes in service provision. This study demonstrates the importance of current information on the status of the national workforce and serves as a model for future studies. 相似文献
6.
7.
N. S. Kalson C. P. Charalambous E. S. Powell A. Hearnden J. K. Stanley 《Hand (New York, N.Y.)》2009,4(3):279-282
A common distal radio-ulnar joint (DRUJ) stabilisation procedure uses a tendon graft running from the lip of the radial sigmoid
notch to the ulnar fovea and through a bony tunnel to the ulnar shaft, before being wrapped round the distal ulna and sutured
to itself. Such graft fixation can be challenging and requires a considerable tendon length. The graft length could be reduced
by fixing the graft to the ulna using a bone anchor or interference screw. The aim of this study was to compare the strength
of three distal ulna graft fixation methods (tendon wrapping and suturing, bone anchor and interference screw). Four human
cadaveric ulnae were used. A tendon strip was run through a tunnel in the distal ulna and secured by: (1) wrapping round the
shaft and suturing it to itself, (2) a bone anchor and (3) an interference screw in the bone tunnel. Load to failure was determined
using a custom-made apparatus and an Instron machine. Maximum failure load was highest for the bone anchor fixation (99.3 ± 23.7 N)
followed by the suturing (96.2 ± 12.1 N), and the interference screw fixation (46.9 ± 5.6 N). There was no significant difference
between the tendon suturing and bone anchor methods, but the tendon suturing was statistically significantly higher compared
to the interference screw (P = 0.028). In performing anatomical stabilisation of the DRUJ fixation of the tendon graft to the distal ulna with a bone
anchor provides the most secure fixation. This may make the stabilisation technique less demanding and require a smaller tendon
graft. 相似文献
8.
9.
Nutritional supplementation, psychosocial stimulation, and growth of stunted children: the Jamaican study 总被引:3,自引:0,他引:3
S P Walker C A Powell S M Grantham-McGregor J H Himes S M Chang 《The American journal of clinical nutrition》1991,54(4):642-648
The benefits of nutritional supplementation, with or without psychosocial stimulation, on the growth of stunted children were evaluated. Children aged 9-24 mo with lengths less than -2 SD of the National Center for Health Statistics references (n = 129) were randomly assigned to four groups: control, nutritional supplementation, stimulation, and both interventions. A fifth group with lengths greater than -1 SD was also enrolled. Length, weight, head and arm circumferences, and triceps and subscapular skinfold thicknesses were measured on enrollment and 6 and 12 mo later. Multiple-regression analysis was used to determine the effects of the interventions in which age, sex, initial status, initial dietary intake, and several socioeconomic variables were controlled for. Stimulation had no effect on growth and there was no interaction between the interventions. After 12 mo supplemented children had significantly increased length, weight, and head circumference (all P less than 0.01). The effects of supplementation were not cumulative but occurred in the first 6 mo. 相似文献
10.