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   6317篇
  免费   465篇
  国内免费   13篇
耳鼻咽喉   75篇
儿科学   265篇
妇产科学   193篇
基础医学   777篇
口腔科学   86篇
临床医学   862篇
内科学   1164篇
皮肤病学   155篇
神经病学   487篇
特种医学   134篇
外科学   657篇
综合类   63篇
一般理论   5篇
预防医学   698篇
眼科学   208篇
药学   476篇
  1篇
中国医学   23篇
肿瘤学   466篇
  2024年   12篇
  2023年   74篇
  2022年   104篇
  2021年   240篇
  2020年   134篇
  2019年   198篇
  2018年   246篇
  2017年   172篇
  2016年   194篇
  2015年   193篇
  2014年   226篇
  2013年   345篇
  2012年   483篇
  2011年   529篇
  2010年   244篇
  2009年   279篇
  2008年   407篇
  2007年   469篇
  2006年   366篇
  2005年   391篇
  2004年   321篇
  2003年   323篇
  2002年   249篇
  2001年   67篇
  2000年   48篇
  1999年   49篇
  1998年   43篇
  1997年   28篇
  1996年   33篇
  1995年   22篇
  1994年   23篇
  1993年   18篇
  1992年   21篇
  1991年   22篇
  1990年   18篇
  1989年   31篇
  1988年   16篇
  1987年   11篇
  1986年   14篇
  1985年   11篇
  1984年   19篇
  1983年   13篇
  1982年   12篇
  1981年   12篇
  1980年   10篇
  1979年   5篇
  1977年   6篇
  1976年   5篇
  1971年   4篇
  1968年   10篇
排序方式: 共有6795条查询结果,搜索用时 453 毫秒
11.
C31G, which has potent activity against the human immunodeficiency virus type 1 (HIV-1) and an established record of safety in animal studies and human trials, is a microbicidal agent comprised of a buffered equimolar mixture of two amphoteric, surface-active agents: an alkyl amine oxide (C14AO) and an alkyl betaine (C16B). Studies of long-term in vitro exposure to C31G and its constituents have suggested that the components of C31G may contribute differentially to its toxicity and efficacy. In the present studies, in vitro assays of cytotoxicity and anti-HIV-1 activity demonstrated that C16B was slightly less cytotoxic compared to either C31G or C14AO, whereas the anti-HIV-1 activities of C31G and its individual constituents were similar. In the murine model of cervicovaginal microbicide toxicity, in vivo exposure to C14AO resulted in severe cervical inflammation followed by a delayed disruption of the columnar epithelium. In contrast, exposure to C16B caused severe cervical epithelial disruption and a secondary, less intense inflammatory response. These results demonstrate that (i) there are both mechanistic and temporal differences in toxicity associated with the components of C31G not necessarily predicted by in vitro assessments of cytotoxicity and (ii) contributions of each component to the anti-HIV-1 activity of C31G appear to be equal. In addition, these findings indicate that direct and indirect mechanisms of in vivo toxicity can be observed as separate but interrelated events. These results provide further insight into the activity of C31G, as well as mechanisms potentially associated with microbicide toxicity.  相似文献   
12.
OBJECTIVE: This study was designed to investigate potential areas of practice for the clinical laboratory scientist (CLS) and to propose a graduate curriculum to prepare the practitioner for an advanced level of practice. DESIGN: Meta-analysis of PharmD, physician assistant, physical therapy, and nurse practitioner curricula focusing on academic and clinical advanced practice was used to develop an educational model and curriculum for a professional doctorate in clinical laboratory science (CLS). MAIN OUTCOME MEASURE: (1) New educational model for CLS advanced practice; (2) A proposed curriculum for a Doctorate of Clinical Laboratory Science degree. RESULTS: A new curriculum model was adapted from established healthcare educational models. CONCLUSION: Although there is a need for a baccalaureate degree in CLS there is also a role for expanded education and responsibilities for CLS practitioners. The CLS Advanced Practitioner design focuses on moving students from the baccalaureate level to the doctoral level and prepares the individual to become an integral part of the healthcare team.  相似文献   
13.
Abstract: Background : Women are increasingly being asked to consider participating in medical research. We sought to investigate views of women who participated in and declined to participate in a study that was part of a program of maternity care research. Methods : An exploratory study using focus group interviews and semistructured interviews was conducted. A purposive sample of 17 postnatal women who had participated in research, from a hospital in the North West of England, were interviewed. An open coding mechanism to identify emergent themes was used for the analysis of data. Results : Of women who had not declined to participate in any research, the following themes were identified: altruism versus self‐protection, enhanced versus inferior care, professional guidance versus self‐direction, and welcome versus unacceptable methodology. Of women who had participated in some research but declined to participate in other research, the following themes were identified: feeling disempowered by the process, inability to believe equipoise existed, and practical inconvenience. Conclusions : These findings suggest that although health care researchers adopt an individualistic approach to care, they may fail to adopt a similar approach within research. What is important and acceptable to women needs to be ascertained to develop appropriate research strategies. This plan will ensure that research is carried out to the highest ethical standard, which may increase recruitment rates.  相似文献   
14.
15.
We report the case of a 25-year-old male patient who presented with complaints of redness, photophobia, and decreased vision in the right eye of a week's duration. Slit-lamp biomicroscopic examination revealed a cream-colored, irregular elevated inferior iris mass, extending on to the anterior lens surface. Differential diagnoses of a fungal granuloma, a medulloepithelioma, and an amelanotic melanoma were considered. An excisional biopsy of the mass was performed through a superior clear corneal incision. Polymerase chain reaction analysis of the aqueous humor showed a positive pan fungal genome. Histopathology of the biopsied mass showed a giant cell granuloma with surrounding numerous branching, septate hyphae. Culture growth revealed Aspergillus fumigatus We report this case because of the rarity of Aspergillus iris granuloma as a primary presentation of endogenous Aspergillosis and review the relevant literature. Absence of a significant systemic history compounded the diagnostic dilemma in our patient. Definitive differentiation of this rare entity from a foreign body, amelanotic melanoma, and other inflammatory conditions such as sarcoidosis and tuberculosis, may be possible only on microbiological and histo-pathological evaluation.  相似文献   
16.
17.
18.
OBJECTIVE: Given the associated risk of general anesthesia in elderly patients with cardiovascular disease, the authors set out to determine the feasibility of transcanal cochlear implantation under local anesthesia with monitored anesthesia care. METHODS: A 70-year-old man with a history of coronary artery bypass grafting, diabetes mellitus, and an American Society of Anesthesiologists Class III cardiac status underwent cochlear implantation under local with monitored anesthesia care. RESULT: With the described technique and regimen of intravenous remifentanil and dexmedetomidine, the patient tolerated the 60-minute procedure without tachycardia, hyper- or hypotension, or cardiac ischemia. CONCLUSION: Cochlear implantation using the pericanal electrode technique performed under local anesthesia with monitored anesthesia care is possible in patients at risk for undergoing general anesthesia for cochlear implantation.  相似文献   
19.
Background. Upper eyelid dermatochalasis is typically treated with excisional blepharoplasty. The role of the CO2 laser previously had been confined to that of a vaporizing, incisional, or hemostatic tool. Over the past several years, however, ablative CO2 laser skin resurfacing has been popularized as an adjunctive treatment to blepharoplasty to minimize periorbital rhytides through its vaporizing as well as skin-tightening action.
Objective. To evaluate the safety and efficacy of a high-energy pulsed CO2 laser as a stand-alone treatment for dermatochalasis and periorbital rhytides.
Methods. Sixty-seven patients (skin phototypes I–IV) with mild-to-severe upper eyelid dermatochalasis and periorbital rhytides received periocular CO2 laser skin treatment. Global assessment scores of dermatochalasis and rhytides were determined by a side-by-side comparison of periocular photographs preoperatively and 1, 3, and 6 months postoperatively. In addition, caliper measurements of upper eyelids before and 1, 3, and 6 months after treatment were obtained.
Results. Both dermatochalasis and periorbital rhytides were significantly improved after periocular CO2 laser skin resurfacing. Patients with more severe dermatochalasis and rhytides showed greater improvement after CO2 laser treatment than did those with mild or moderate involvement. Side effects were limited to erythema and transient hyperpigmentation. No scarring, hypopigmentation, or ectropion were observed.
Conclusions. Periocular skin resurfacing with a CO2 laser can safely and effectively improve upper eyelid dermatochalasis and periorbital rhytides.  相似文献   
20.
1,450 nm Long-Pulsed Diode Laser for Nonablative Skin Rejuvenation   总被引:1,自引:0,他引:1  
Doshi Seema N.  MD    Alster Tina S.  MD 《Dermatologic surgery》2005,31(S3):1223-1226
Background:. There has been growing patient demand for laser technology to treat rhytids and to refine skin texture without the associated lifestyle hindrance common to ablative cutaneous procedures. Nonablative laser systems have been developed to meet this need and, in many instances, have replaced ablative lasers as the preferred treatment modality.
Objective:. To review long-pulsed diode laser technology in the treatment of a variety of cutaneous disorders.
Materials and Methods. All publications involving 1,450 nm long-pulsed diode laser technology were reviewed and discussed.
Results. The latest generation of nonablative lasers, in the midinfrared electromagnetic spectrum, selectively targets and heats dermal tissue to stimulate collagen remodeling while sparing the epidermis.
Conclusions. Demonstrating efficacy in the treatment of a wide range of cutaneous disorders, including facial rhytids, acne vulgaris, and atrophic scars, the 1,450 nm diode laser is a useful addition to the nonablative laser armamentarium.  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