全文获取类型
收费全文 | 5737篇 |
免费 | 731篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 126篇 |
儿科学 | 191篇 |
妇产科学 | 456篇 |
基础医学 | 638篇 |
口腔科学 | 67篇 |
临床医学 | 1216篇 |
内科学 | 981篇 |
皮肤病学 | 94篇 |
神经病学 | 573篇 |
特种医学 | 375篇 |
外科学 | 638篇 |
综合类 | 151篇 |
一般理论 | 2篇 |
预防医学 | 364篇 |
眼科学 | 80篇 |
药学 | 201篇 |
中国医学 | 1篇 |
肿瘤学 | 327篇 |
出版年
2023年 | 53篇 |
2020年 | 57篇 |
2019年 | 55篇 |
2018年 | 125篇 |
2017年 | 120篇 |
2016年 | 110篇 |
2015年 | 145篇 |
2014年 | 166篇 |
2013年 | 193篇 |
2012年 | 159篇 |
2011年 | 212篇 |
2010年 | 171篇 |
2009年 | 172篇 |
2008年 | 181篇 |
2007年 | 211篇 |
2006年 | 180篇 |
2005年 | 195篇 |
2004年 | 166篇 |
2003年 | 172篇 |
2002年 | 161篇 |
2001年 | 186篇 |
2000年 | 175篇 |
1999年 | 169篇 |
1998年 | 155篇 |
1997年 | 153篇 |
1996年 | 152篇 |
1995年 | 131篇 |
1994年 | 92篇 |
1993年 | 76篇 |
1992年 | 145篇 |
1991年 | 149篇 |
1990年 | 127篇 |
1989年 | 143篇 |
1988年 | 129篇 |
1987年 | 118篇 |
1986年 | 137篇 |
1985年 | 114篇 |
1984年 | 99篇 |
1983年 | 78篇 |
1982年 | 58篇 |
1981年 | 56篇 |
1980年 | 45篇 |
1979年 | 67篇 |
1978年 | 61篇 |
1977年 | 57篇 |
1976年 | 49篇 |
1975年 | 50篇 |
1974年 | 57篇 |
1973年 | 52篇 |
1971年 | 46篇 |
排序方式: 共有6481条查询结果,搜索用时 93 毫秒
1.
2.
D Van Neste† RM Trüeb‡ 《Journal of the European Academy of Dermatology and Venereology》2006,20(5):578-583
BACKGROUND: Computer-assisted image analysis has been proposed for human hair growth studies. METHODS: The performances of Trichoscan, a commercially available automated system combining epiluminiscence microscopy with digital image analysis, developed for office-based hair growth measurements, have been evaluated comparatively on the same skin sites using standardized photographic equipment and calibrated processing for contrast-enhanced phototrichogram (CE-PTG) analysis. This reference method has been validated with scalp biopsies and histological examination of serial sectioning. RESULTS: Besides edge effects, hair fibres escaped the Trichoscan analysis for various reasons including, but not limited to, thickness, pigmentation, closeness and crossing. CONCLUSION: Most of these problems have been identified in the late 1980s and remain largely unsolved by the processing software that was evaluated in 2004. Therefore claims promoting the Trichoscan method for accurate hair measurements in clinical trials on scalp and body hair are not supported by the present investigation. The speed at which the analysis is performed is outweighed by the errors in signal detection. Therefore we suggest that improvements must be clearly documented before Trichoscan is established for quantified diagnostic purposes and detailed hair cycle monitoring during hair trials. 相似文献
3.
4.
Reevaluation of procarbazine for the treatment of recurrent malignant central nervous system tumors 总被引:1,自引:0,他引:1
Ninety-nine patients with primary recurrent malignant tumors of the central nervous system were treated with procarbazine as a single agent. Procarbazine was not given as a specified protocol, but for patients who were ineligible or refused other protocols. All patients had been treated previously with radiotherapy and 96 patients had also received previous chemotherapy. Twenty-five patients were treated at the first progression of their tumor, 47 were treated at the second progression, and 27 were treated at the third progression of their tumor. For the aggregate, the response plus stabilization rate was 27% for glioblastoma multiforme with median time to tumor progression of 30 weeks, and 28% for other anaplastic gliomas with a median time to tumor progression of 49 weeks. With respect to the percent of patients who responded or stabilized to treatment, these results are inferior to those reported previously for patients treated with procarbazine at recurrence. With respect to duration of response and stabilization, the data are comparable. 相似文献
5.
The 5-year results of a randomized trial of adjuvant radiation therapy after chemotherapy in breast cancer patients treated with mastectomy 总被引:4,自引:0,他引:4
K L Griem I C Henderson R Gelman D Ascoli B Silver A Recht R L Goodman S Hellman J R Harris 《Journal of clinical oncology》1987,5(10):1546-1555
The use of adjuvant radiation therapy in breast cancer patients treated with mastectomy and adjuvant chemotherapy has been controversial. In order to assess the necessity and effectiveness of adjuvant radiation therapy in this setting, we reviewed the results in 510 patients with T1-T3 tumors and pathologically positive nodes or tumors larger than 5 cm and negative nodes who were treated with adjuvant chemotherapy. Patients with four or more positive nodes or at least one positive apical node were randomized to receive either five or ten cycles of cyclophosphamide/Adriamycin (Adria Laboratories, Columbus, OH) (CA) and patients with one to three positive nodes or operable tumors larger than 5 cm and pathologically negative nodes were randomized to receive eight cycles of either cyclophosphamide, methotrexate, and 5-fluorouracil (5-FU) (CMF) or methotrexate and 5-FU (MF) chemotherapy. Two hundred six of these patients were subsequently rerandomized to receive either no further treatment or adjuvant radiotherapy. Thirty-five patients withdrew after randomization, including 34 who declined to receive radiotherapy. Radiation therapy consisted of 4,500 cGy in 5 weeks to the chest wall and appropriate draining lymph nodes. Median follow-up from chemotherapy randomization is 45 months for patients in the CA arm and 53 months for those in the CMF/MF arm. The crude rate of local failure (chest wall or draining lymph node areas) as first site of failure for patients randomized to receive chemotherapy only was 14%; for those randomized to receive both chemotherapy and radiotherapy it was 5% (P = .03). For patients in the CMF/MF arm, the rate of local failure as the first site of failure was nearly the same for patients randomized to chemotherapy only as for those randomized to adjuvant radiotherapy as well (5% v 2%). For patients in the CA arm, the crude rate of local failure was 20% for patients randomized to receive chemotherapy only, and 6% for those randomized to both types of adjuvant treatment (P = .03). Among the 43 patients treated with CA who actually received radiotherapy, there was only one local failure, compared with 12 local failures among the 59 patients (20%) who actually did not receive radiotherapy (P = .007). No significant difference was seen in disease-free survival or overall survival in either the CA or the CMF/MF arm between patients randomized to receive radiation therapy and those randomized to no further treatment.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
6.
Richard T. Silver MD 《Current hematologic malignancy reports》2007,2(1):43-46
Polycythemia vera is a myeloproliferative disease, which, if untreated, leads to thrombohemorrhagic complications and eventually
to progressive myelofibrosis, anemia, and splenomegaly. Two newly available drugs, interferon alfa and imatinib mesylate,
may alter the course of this disease. Used as single agents, each produces lasting remissions in about 75% of patients with
polycythemia vera. Of significance, change in JAK2 expression has been reported after treatment with both agents. 相似文献
7.
Extranodal lymphomas presenting as soft tissue sarcomas to a sarcoma service over a two-year period.
J K O'Neill V Devaraj D A T Silver P Sarsfield C A Stone 《Journal of plastic, reconstructive & aesthetic surgery》2007,60(6):646-654
Non-Hodgkin's lymphoma usually presents with lymphadenopathy at multiple sites but can also involve any part of the musculoskeletal system. Occasionally the presentation is with a soft tissue mass. The presentation of large, superficial lymphomatous masses is similar both clinically and radiologically to that of soft tissue sarcomas. The six cases of lymphoma presenting to the Exeter Sarcoma Service as suspected soft tissue sarcomas, over a two-year period (2002-2004), are presented. We describe the clinical and imaging characteristics of these tumours and their subsequent management. Our cases showed variability in presentation. Only one of the six cases presented with pain and one with tenderness. Four of the cases had no lymphadenopathy and the other two had lymphadenopathy restricted to one nodal basin. Overlying soft tissue swelling occurred in four cases and in distal limb swelling beyond the mass in one case. Radiologically, lymphomas are known to be likely to exhibit confluent lymphadenopathy that is rare in patients with soft tissue sarcoma. Confluent lymphadenopathy was demonstrated in only one case of this series of patients. It is thought that lymphomas infiltrate across anatomical fascial planes more readily than sarcomas and in four of our six cases this feature was present. Clinical history, examination and MRI are insufficient to differentiate between soft tissue sarcoma and lymphoma and the importance of obtaining a pathological diagnosis prior to surgery is clear. It is crucial to differentiate lymphoma from sarcoma in order to avoid unnecessary excisional procedures in lymphoma patients. 相似文献
8.
The effect of an informational program in which the benefits and disadvantages of directed donations are discussed directly with the prospective recipient of the blood and/or that patient's family was examined during a 20-month period. Data collected for 27 regional Connecticut hospitals that accept directed donations were compared with similar data for Hartford Hospital, an 885-bed tertiary-care facility. The number of directed-donor units (68) collected by the American Red Cross Blood Services for Hartford Hospital during the study period was comparable to the number (average, 62.3) provided for smaller (301-450 beds) institutions in the state. The percentage that directed-donor units drawn for Hartford Hospital represented of the total number of homologous units provided (0.23%) was less than that for any of the categories of hospitals, by size, in the state. Supplying the patient and/or the patient's family, in a personalized manner, with information concerning the advantages and disadvantages of directed as well as of volunteer donor blood can result in a marked overall reduction in the number of directed donations and also serves to reassure those concerned about blood transfusion. 相似文献
9.
10.
The case of the missing secretary: DHEW's failed efforts to create a Cabinet secretary of health.
下载免费PDF全文
![点击此处可从《American journal of public health》网站下载免费的PDF全文](/ch/ext_images/free.gif)
G A Silver 《American journal of public health》1997,87(4):681-686
In response to professional and political pressures in 1967, an incident occurred at the Department of Health, Education, and Welfare that illustrates the delicacy and complexity of the legislative process. In an effort to bypass interest group influences, the undersecretary of the Department undertook a maneuver that backfired and frustrated an opportunity that might have resulted in the establishment of a Cabinet office of Health. In addition to demonstrating the sensitivity of the legislative process, and the dangers of overconfidence in dealing with the process, the events also offer moral guidance: too stubborn, idealistic convictions of good people, however well intentioned the actions, may serve to defeat the desired ends. 相似文献