全文获取类型
收费全文 | 5478篇 |
免费 | 336篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 100篇 |
儿科学 | 220篇 |
妇产科学 | 183篇 |
基础医学 | 618篇 |
口腔科学 | 110篇 |
临床医学 | 578篇 |
内科学 | 1023篇 |
皮肤病学 | 211篇 |
神经病学 | 345篇 |
特种医学 | 125篇 |
外国民族医学 | 2篇 |
外科学 | 524篇 |
综合类 | 71篇 |
一般理论 | 4篇 |
预防医学 | 551篇 |
眼科学 | 493篇 |
药学 | 354篇 |
中国医学 | 5篇 |
肿瘤学 | 321篇 |
出版年
2023年 | 59篇 |
2022年 | 75篇 |
2021年 | 206篇 |
2020年 | 135篇 |
2019年 | 160篇 |
2018年 | 220篇 |
2017年 | 168篇 |
2016年 | 166篇 |
2015年 | 145篇 |
2014年 | 232篇 |
2013年 | 324篇 |
2012年 | 430篇 |
2011年 | 466篇 |
2010年 | 231篇 |
2009年 | 145篇 |
2008年 | 311篇 |
2007年 | 353篇 |
2006年 | 279篇 |
2005年 | 324篇 |
2004年 | 285篇 |
2003年 | 317篇 |
2002年 | 206篇 |
2001年 | 103篇 |
2000年 | 18篇 |
1999年 | 19篇 |
1998年 | 44篇 |
1997年 | 67篇 |
1996年 | 19篇 |
1995年 | 19篇 |
1994年 | 13篇 |
1993年 | 17篇 |
1992年 | 13篇 |
1991年 | 15篇 |
1990年 | 16篇 |
1989年 | 21篇 |
1988年 | 12篇 |
1987年 | 11篇 |
1986年 | 8篇 |
1985年 | 15篇 |
1983年 | 10篇 |
1982年 | 10篇 |
1981年 | 8篇 |
1980年 | 15篇 |
1978年 | 8篇 |
1974年 | 8篇 |
1973年 | 7篇 |
1972年 | 12篇 |
1971年 | 9篇 |
1970年 | 10篇 |
1969年 | 11篇 |
排序方式: 共有5838条查询结果,搜索用时 15 毫秒
1.
2.
3.
Cough and paradoxical vocal fold motion 总被引:8,自引:0,他引:8
Kenneth W. Altman MD PhD C. Blake Simpson MD Milan R. Amin MD Mona Abaza MD Ron Balkissoon MD Roy R. Casiano MD 《Otolaryngology--head and neck surgery》2002,127(6):501-511
OBJECTIVES: The differential diagnosis and treatment of patients with chronic cough, paradoxical vocal fold motion, and disordered breathing can be a challenge to most practicing otolaryngologists. Tracheobronchial (ie, asthma, bronchitis, and tracheal stenosis), laryngeal (ie, vocal fold paralysis and neoplasms), and rhinologic (ie, allergies and rhinosinusitis) etiologies are commonly diagnosed and treated effectively. However, occasionally one is faced with patients who are refractory to medical treatment and have no obvious rhinologic, laryngeal or pulmonary cause. STUDY DESIGN AND SETTING: We conducted a review of the literature. METHODS: We present a thorough review of the current medical literature exploring the complex neurologic mechanisms involved in the production of cough and the relationship between gastroesophageal reflux disease, vagal neurapathy, and paradoxical vocal fold motion. RESULTS: The diagnosis and successful treatment of chronic cough can be complex. It requires a thorough understanding of the neurologic mechanisms behind cough excitation and suppression. Successful treatment strategies include aggressive management of the patient's reactive airway disease, gastroesophageal reflux disease, and, in select cases, paradoxical vocal fold motion. This may involve a well-coordinated effort among pulmonologists, otolaryngologists, gastroenterologists, and speech pathologists. CONCLUSION: Gastroesophageal reflux disease, vagal neuropathy, and paradoxical vocal fold motion are additional causes of chronic cough and disordered breathing that need to be considered, in the absence of obvious laryngotracheal and/or rhinologic pathology. A high index of suspicion is essential in making the diagnosis and formulating an effective multidisciplinary treatment plan for these patients. 相似文献
4.
Enyioma N OBINECHE Michael PT GILLETT Abdishakur ABDULLE Mustapha SULAIMAN Mona AL-ROKHAIMI 《Nephrology (Carlton, Vic.)》2002,7(3):115-120
SUMMARY: In patients with chronic renal failure (CRF), hyperleptinaemia has been widely reported, but the exact mechanisms leading to elevated leptin levels are unclear. Impaired renal clearance of leptin and the influence of other hormones may be important. In this study, we measured serum leptin levels in 150 patients on haemodialysis, peritoneal dialysis or in the predialysis phase of CRF. Furthermore, we measured plasma levels of insulin, growth hormone (GH) and insulin-like growth factor 1 (IGF-1), as well as plasma levels of triacylglycerols and total low density lipoprotein (LDL)- and high density lipoprotein (HDL)-cholesterol. We observed significantly elevated levels of leptin, particularly in female patients, and leptin was shown to correlate significantly with insulin, total and LDL-cholesterol and log triacylglycerols. Leptin was inversely correlated with GH concentrations, but was not correlated with IGF-1 levels. Despite the multiple correlations established between leptin levels and other variables, only hyperinsulinaemia in CRF seems to be important as a determinator of leptin levels. 相似文献
5.
6.
THOMAS M. JUNG MD PhD RAJ P. TERKONDA MD STEPHEN J. HAINES MD SCOTT STROME MD LAWRENCE J. MARENTETTE MD From the 《Otolaryngology--head and neck surgery》1997,116(6):642-646
The classic approach to anterior skull base lesions uses bifrontal craniotomies together with lateral rhinotomies. This approach requires frontal lobe retraction and is associated with postoperative anosmia and the development of frontal lobe encephalomalacia. The transglabellar/subcranial approach permits removal of anterior skull base lesions without frontal lobe retraction and avoids facial scars. No studies to date, however, have directly compared the two approaches in terms of patient morbidity. The present retrospective study compares the two approaches when used for the removal of anterior skull base lesions in terms of estimated blood loss, number of transfusions, number of days in the hospital and intensive care unit, and postoperative complications. Twenty patients with anterior skull base lesions were examined. The classic approach was used on 10, and the transglabellar/subcranial route was used on 10. When compared with the classic approach, the transglabellar/subcranial approach resulted in a lower estimated blood loss and subsequent transfusion rate, fewer days in the hospital and intensive care unit, and lower numbers and less severe types of complications. Furthermore, visualization of the tumors before resection with the transglabellar/subcranial approach allowed preservation of olfaction in virtually all of these patients. Although this study represents a small sample population, the results are sufficiently impressive to favor the transglabellar/subcranial approach for the removal of a variety of anterior skull base lesions. (Otolaryngol Head Neck Surg 1997;116:642-6.) 相似文献
7.
FREDERIC W-B. DELEYIANNIS MD MPhil MPH DAVID B. THOMAS MD DrPH From the Departments of Otolaryngology–Head Neck Surgery Epidemiology University of Washington Seattle; the Division of Public Health Science Fred Hutchinson Cancer Research Center. 《Otolaryngology--head and neck surgery》1997,116(6):630-636
A cohort of 5180 patients with head and neck cancer, who were part of the tumor registry of the Surveillance, Epidemiology, and End Results area of western Washington State, was followed up for as many as 15 years to determine the risk of lung cancer. A sample of 522 patients from this cohort was interviewed to determine smoking history. Lung cancer developed in 356 (6.9%) of the 5180 patients. The overall annual incidence of lung cancer remained relatively constant between approximately 1.0% and 2.0% during the 15 years of follow-up. Men had an increased risk of lung cancer compared with women (relative risk [RR] = 1.56; 95% confidence interval [CI] = 1.18 to 2.03). Compared with patients with oral cavity cancer (RR = 1.00), the relative risk of lung cancer developing by the site of the index tumor was 0.63 (95% CI = 0.40 to 0.98) for lip, 1.12 (95% CI = 0.81 to 1.56) for intrinsic larynx, 1.73 (95% CI = 1.21 to 2.47) for oropharynx, 1.84 (95% CI = 1.16 to 2.92) for hypopharynx, and 2.28 (95% CI = 1.60 to 3.24) for extrinsic larynx. Among the 522 patients who were interviewed, men smoked more than women ( p < 0.0001), and patients with laryngeal or pharyngeal cancer smoked more than patients with cancer of the lip or the oral cavity ( p < 0.05). Among patients with head and neck cancer, the risk of lung cancer is highest for men and for patients with cancer of the pharynx or extrinsic larynx. These findings may be explained by differences in smoking consumption. (Otolaryngol Head Neck Surg 1997;116:630-6.) 相似文献
8.
Randolph G. Statius van Eps MD Glenn M. LaMuraglia MD From the Division of Vascular Surgery General Surgical Services Wellman Laboratories of Photomedicine Massachusetts General Hospital Harvard Medical School. 《Journal of vascular surgery》1997,25(6)
Purpose: The multifunctional cytokine, transforming growth factor β1 (TGF-β), plays an important role in the development of injury-associated intimal hyperplasia (IH). Strategies to suppress local TGF-β activity may have a clinical potential to prevent restenosis caused by IH. Photodynamic therapy (PDT) involves the local generation of cytotoxic free radicals by light activation of photosensitizer dyes and has been shown to inhibit experimental IH. This study investigated whether PDT-generated free radicals can affect TGF-β activity in a biologic system using vascular smooth muscle cells (SMCs).Methods: The release and activation of TGF-β by injured SMCs in culture was compared between mechanical injury and PDT. Mechanical injury was induced with a rubber policeman, and PDT was performed with the photosensitizer chloroaluminum sulfonated phthalocyanine (5 μg/ml) and 675 nm laser light at subtherapeutic 10 J/cm2 and the in vivo therapeutic dose of 100 J/cm2. Cell viability was assessed by the tetrazolium salt conversion assay, and active and total (active + latent) TGF-β was determined by enzyme-linked immunosorbent assay in the conditioned media of SMCs 24 hours after treatment. Functional TGF-β activity was assessed by inhibition of endothelial cell mitogenesis.Results: Both forms of injury severely reduced (p < 0.0005) SMC viability to less than 15%. In untreated SMC conditioned media, only 14.5% of the total TGF-β was active (27.7 ± 8.7 pg per 1 × 105 cells). However, after mechanical injury and PDT with 10 J/cm2, there was a significant increase (p < 0.02) in active TGF-β (60.1 ± 10.1 pg and 48.6 ± 21.0 pg, respectively), despite a total reduction of approximately 50%. In contrast to this result, PDT with 100 J/cm2 did not result in increased levels of active TGF-β (8.1 ± 3.5 pg), despite having similar levels of total TGF-β. Consequently, the conditioned media of SMCs that had 100 J/cm2 PDT did not inhibit endothelial cell mitogenesis as compared with the conditioned media of SMCs with mechanical injury and 10 J/cm2 PDT (p < 0.0002).Conclusions: This report describes two novel findings: (1) injury to SMCs in vitro induces the conversion of biologically latent TGF-β to active TGF-β; and (2) the therapeutic PDT dose interferes with this injury activation process. This study substantiates the concept of local cytokine inhibition by PDT in a biologic system and provides new insights into the mechanisms of PDT-mediated inhibition of experimental IH. (J Vasc Surg 1997;25:1033-43.) 相似文献
9.
10.
Halo nevi are characterized by progressive degeneration of nevus cells surrounded by a mononuclear cell infiltrate. We studied the morphological features of the nevus cells and the composition of the mononuclear cell infiltrate in 15 cases of halo nevi using immunohistochemical techniques and a battery of antibodies to different subsets of lymphocytes and histiocytes. Regression could be divided into four more or less identifiable stages, associated with different subsets of lymphocytes and monocyte-macrophage lineage cells. Stage I (preregression): nests of unremarkable nevus cells were surrounded by a moderate number of T lymphocytes (relatively small percentage of helper/inducer T cells), occasional B cells and macrophages. Stage II (early regression): large number of T lymphocytes and FXIIIa-positive cells were in close contact with nevus cell clusters which showed ragged edges. Lysozymepositive cells and epidermal Langerhans cells were mildly increased. Stage III (late regression): single nevomelanocytes showing mild atypia were present. Numerous T lymphocytes and macrophages positive for lysozyme, KP1 and/or FXIIIa were interspersed between the nevus cells. Increased numbers of epidermal Langerhans cells were present. Stage IV (complete regression): no nevus cells were observed and moderate numbers of T lymphocytes only remained. These results suggest that T cells, especially T-suppressor cells, and different subsets of macrophages participate in the regression of the nevi. 相似文献