首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   13609篇
  免费   889篇
  国内免费   15篇
耳鼻咽喉   94篇
儿科学   372篇
妇产科学   370篇
基础医学   1735篇
口腔科学   613篇
临床医学   1422篇
内科学   2670篇
皮肤病学   266篇
神经病学   1224篇
特种医学   437篇
外科学   1836篇
综合类   441篇
一般理论   12篇
预防医学   1277篇
眼科学   313篇
药学   772篇
中国医学   14篇
肿瘤学   645篇
  2023年   72篇
  2022年   117篇
  2021年   259篇
  2020年   132篇
  2019年   238篇
  2018年   250篇
  2017年   174篇
  2016年   204篇
  2015年   227篇
  2014年   316篇
  2013年   499篇
  2012年   690篇
  2011年   733篇
  2010年   407篇
  2009年   332篇
  2008年   633篇
  2007年   721篇
  2006年   661篇
  2005年   643篇
  2004年   618篇
  2003年   569篇
  2002年   558篇
  2001年   331篇
  2000年   329篇
  1999年   308篇
  1998年   152篇
  1997年   118篇
  1996年   108篇
  1995年   105篇
  1994年   113篇
  1993年   93篇
  1992年   251篇
  1991年   244篇
  1990年   264篇
  1989年   215篇
  1988年   235篇
  1987年   224篇
  1986年   199篇
  1985年   223篇
  1984年   122篇
  1983年   126篇
  1982年   98篇
  1981年   88篇
  1980年   82篇
  1979年   106篇
  1978年   102篇
  1976年   77篇
  1974年   71篇
  1972年   71篇
  1971年   80篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.

Purpose

The cost consequences of alternative treatment modalities for benign prostatic hyperplasia (BPH) were investigated. The present lifetime costs of watchful waiting, medical management and surgery alone and in various combinations were estimated for a synthetic cohort of men comprised of 5 age groupings.

Materials and Methods

Synthetic cohort models were constructed to follow men at different ages “analytically” for specific intervals and to calculate the cumulative health care costs associated with alternative BPH treatment regimens during those periods. These models accounted explicitly for survival probabilities, the use of different types of health care services and products, price changes for those services and products, failure rates of some therapies and a discount factor needed to compute the present value of the cost streams. The models were implemented with hospital discharge and other data on BPH incident cases in the state of Florida in approximately 1989.

Results

The addition of medical management to the mix of therapies is likely to increase overall health care spending on BPH treatment, perhaps by a considerable amount. The cost-effectiveness of each type of BPH therapy differs by the age of the patient at which it is first initiated. All other parameters being equal, surgery appears to be more cost-effective at younger patient ages, while medical management has a cost advantage at older ages.

Conclusions

The cost implications of alternative BPH therapies are substantial, and warrant more detailed consideration by clinicians and health policy specialists.  相似文献   
102.
103.
In two normal subjects the sciatic nerve was blocked completely using concentrated lidocaine. The muscle afferent and reflex electromyographic responses to reproducible percussion of the Achilles tendon were recorded while the blocks developed. The intensity of percussion was sufficient to produce an Achilles tendon jerk in one subject when at rest and in the other during reinforcement. The block did not alter the muscle afferent response to tendon percussion in either subject. It is concluded that background fusimotor activity is not a prerequisite for the tendon jerk and that, during complete relaxation, there may be no significant fusimotor drive directed to the triceps surae. The varying ease with which tendon jerks can be elicited in different normal subjects or in different muscles of the same subject appears to be related not to fusimotor activity but to differences in the "central excitability state."  相似文献   
104.
A bilayer artificial skin composed of a temporary Silastic epidermis and a porous collagen-chondroitn 6-sulfate fibrillar dermis, which is not removed, has been used to physiologically close up to 60% of the body surface following prompt excision of burn wounds in ten patients whose total burn size covered 50--95% body surface area (BSA). Following grafting, the dermal portion is populated with fibroblasts and vessels from the wound bed. The anatomic structure of the artificial dermis resembles normal dermis and serves as a template for the synthesis of new connective tissue and the formation of a "neodermis," while it is slowly biodegraded. This artificial skin has physiologically closed excised burn wounds for periods of time up to 46 days before the Silastic epidermis was removed. At the time of election when donor sites are ready for reharvesting, the Silastic epidermis is removed from the vascularized artificial dermis and replaced with 0.004 autoepidermal graft in sheet or meshed form. Clinical and histologic experience in a relatively short follow-up period (2--16 months) indicates that "neodermis" retains some of the anatomic characteristics and behavior of normal dermis, thus promising improvement in the functional and cosmetic results, as well as providing physiologic function as a skin substitute. The artificial skin is easily sterilized and stored at room temperature, capable of large scale production, and immediately available for grafting, indicating its potential for easy and relatively economic use in the burn patient.  相似文献   
105.
A blood flow calibration apparatus is described for use with electromagnetic flow probes. It is an automatic gravity-flow system, which provides a constant level and therefore constant flow at any preset rate. On several occasions, the use of this device has helped to determine whether flow probes require simple adjustment, factory repair, or replacement. Using this system, a systematic error in the manufacturer's "precalibration" averaging +22% (range, 9 to 50%) has been discovered, and appropriate corrections have been made. The accuracy of these corrections has been confirmed by a rapid, in vivo method of calibration, which also is described and which can be carried out during the conduct of aortocoronary bypass operation. It is recommended that all groups measuring coronary graft flow become familiar with their electromagnetic flowmeter and probes by means such as those described, in the interest of accurate flow measurement after bypass operation.  相似文献   
106.
The members of a Catholic health care facility individually and corporately celebrate Christ's presence in the fullness of eucharistic faith. To be in a Catholic hospital is to have a Gospel experience among Gospel people.  相似文献   
107.
Examination of the causes of late mortality in multiple trauma patients reveals that as much as 78% of all deaths may be attributed to septic complications, suggesting the value of understanding the prevention and treatment of traumatic sepsis. In penetrating trauma, the protective features of the skin are eliminated, and systemic mechanisms of host defense are compromised. These changes in the host defense mechanism and the risk of infection influence the choice and technical features of wound closure and the use of antibiotics. Early diagnosis is imperative, but difficult.  相似文献   
108.
M Burke 《Hospitals》1991,65(6):29-30
For hospital officials who feel wronged by Medicare's payment system, a recent opportunity to appeal geographic status has stirred new hope for survival. Last September, the Health Care Financing Administration published interim final regulations detailing criteria hospitals have to meet to merit reclassification; hospitals had until Nov. 6, 1990, to file their appears. Now, officials are slogging through nearly 1,000 completed applications. "There has been pent-up demand for some review" of geographic classification, says one official.  相似文献   
109.
110.
Surgical resection offers distinct theoretical advantages as the "local" modality in treatment of Stage I and II small cell carcinoma of the lung. We have treated 10 such patients by initial resection since 1975; all survivors but one received adjuvant chemotherapy for the full course thereafter. One patient died of a pulmonary embolus; the other nine remain without evidence of disease from 7 to 69 months after resection. A trial was undertaken of extended indications for resection in selected patients with Stage III-M0 disease. Criteria for patient selection have been developed gradually; these exclude patients for reasons of refusal, physiological inadequacy, disease unsuited to gross total eradication, or lack of adequate initial response to chemotherapy. Of six patients who survived the exclusion criteria and underwent resection, one has had a relapse at 26 months. All others remain without evidence of disease, 5 to 25 months after the start of treatment. We believe that systematic patient selection on the basis of defined criteria will identify a subset of patients having markedly improved chances for disease control. This group may represent as many as half of the patients first presenting with localized or MO disease. Patients excluded as candidates for resection have continued to receive standard nonsurgical combined-modality therapy.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号