全文获取类型
收费全文 | 1723716篇 |
免费 | 136599篇 |
国内免费 | 4103篇 |
专业分类
耳鼻咽喉 | 24294篇 |
儿科学 | 55222篇 |
妇产科学 | 49765篇 |
基础医学 | 250515篇 |
口腔科学 | 49881篇 |
临床医学 | 154645篇 |
内科学 | 329597篇 |
皮肤病学 | 37259篇 |
神经病学 | 138388篇 |
特种医学 | 67907篇 |
外国民族医学 | 462篇 |
外科学 | 263441篇 |
综合类 | 44959篇 |
现状与发展 | 2篇 |
一般理论 | 632篇 |
预防医学 | 135964篇 |
眼科学 | 40824篇 |
药学 | 126939篇 |
3篇 | |
中国医学 | 3365篇 |
肿瘤学 | 90354篇 |
出版年
2018年 | 16727篇 |
2016年 | 14926篇 |
2015年 | 17121篇 |
2014年 | 23811篇 |
2013年 | 36485篇 |
2012年 | 48503篇 |
2011年 | 51317篇 |
2010年 | 30431篇 |
2009年 | 28675篇 |
2008年 | 48177篇 |
2007年 | 51715篇 |
2006年 | 51982篇 |
2005年 | 50427篇 |
2004年 | 49244篇 |
2003年 | 47314篇 |
2002年 | 45821篇 |
2001年 | 75246篇 |
2000年 | 76869篇 |
1999年 | 64813篇 |
1998年 | 18996篇 |
1997年 | 17348篇 |
1996年 | 17205篇 |
1995年 | 16357篇 |
1994年 | 15524篇 |
1993年 | 14545篇 |
1992年 | 53679篇 |
1991年 | 52607篇 |
1990年 | 51702篇 |
1989年 | 49973篇 |
1988年 | 46089篇 |
1987年 | 46024篇 |
1986年 | 43236篇 |
1985年 | 42014篇 |
1984年 | 31993篇 |
1983年 | 27371篇 |
1982年 | 16795篇 |
1981年 | 15342篇 |
1979年 | 31099篇 |
1978年 | 22490篇 |
1977年 | 18980篇 |
1976年 | 17780篇 |
1975年 | 18920篇 |
1974年 | 23249篇 |
1973年 | 22395篇 |
1972年 | 20896篇 |
1971年 | 19418篇 |
1970年 | 18354篇 |
1969年 | 17484篇 |
1968年 | 15960篇 |
1967年 | 14511篇 |
排序方式: 共有10000条查询结果,搜索用时 318 毫秒
991.
G Ciprandi A Scordamaglia S Ruffoni G Pizzorno G W Canonica 《Current medical research and opinion》1986,10(5):346-350
Fifteen patients with cutaneous signs and symptoms caused by adverse reactions to foods were treated in an open trial with ketotifen for 4 to 6 weeks. Seven subjects were allergic and 8 had food intolerance. Each patient was treated with a single dose of ketotifen daily: 2 mg half an hour before going to sleep. Clinical improvement was achieved in 6 out of 7 allergic patients and in 6 out of 8 patients with food intolerance. Since several drugs have been demonstrated to have an influence on immune response, the in vitro effects of ketotifen on some immunological parameters were also studied. Ketotifen showed a significant inhibitory effect on autologous mixed lymphocyte reaction responsiveness. 相似文献
992.
A retrospective review was conducted of 1,230 human poison exposures in which syrup of ipecac was administered to determine the availability of this emetic. Ipecac was available in 41.1% of the homes, while 42.5% obtained it from the pharmacy. Eight and two tenths percent were referred to a health care facility, 2.9% obtained ipecac from a neighbor, 2.3% went to an emergency room prior to calling the poison center, and 3% obtained ipecac from other sources. A randomly selected sample of 150 of these 1,230 cases were contacted 6 months after their initial call to the poison center to determine any changes in the availability of syrup of ipecac in the home. Although almost 30% more homes had syrup of ipecac than previously, 22.2% of homes still did not have ipecac available, despite the previous poisoning experience. Greater effort should be made during follow-up to educate the public regarding ipecac and its use. 相似文献
993.
Familial achalasia associated with adrenocortical insufficiency, alacrima, and neurological abnormalities 总被引:1,自引:0,他引:1
We report on two brothers with achalasia, adrenocortical insufficiency, alacrima, short stature, microcephaly, ataxia, optic atrophy, and developmental delay. The parents and three sibs are unaffected. Achalasia, adrenocortical insufficiency, and alacrima comprise a recently characterized familial multisystem disorder of unknown cause. Achalasia has also been described in association with microcephaly and mental retardation in one family and ataxia, optic atrophy, and mental retardation in another. The above reports and these sibs may represent variants of a single pleiotropic recessive gene. We suggest that abnormalities of the central nervous system are a manifestation of the achalasia, adrenocortical insufficiency, alacrima syndrome. 相似文献
994.
R Mandeville F Dumas A Amarouch S Sidrac-Ghali M C Walker M Zelechowska I Ajdukovic B Grouix 《Hybridoma》1987,6(5):441-451
This study reports the purification and characterization of a high molecular weight human breast cancer-associated antigen identified by a previously described (1,2) murine monoclonal antibody, BCD-B4. Immunohistochemical analysis indicated that BCD-B4 recognizes an antigen expressed in an altered form on the human breast carcinoma cell line, BT-20, compared to the non-malignant human mammary epithelial cell line, HBL-100. Chemical treatments and enzymatic digestions suggested that the recognized moiety was a protein. The antigenic determinant was resistant to neuraminidase and periodate treatments but was sensitive to trypsin and proteinase K. The antigen was purified by affinity chromatography and its molecular weight, determined by SDS-PAGE analysis under non-reducing conditions, was proven to be 250 Kd. Under reducing conditions, the molecule dissociated into two polypeptides of 125 and 45 Kd, respectively. Both subunits could be isolated from normal HBL-100 and neoplastic BT-20 cellular protein extracts by affinity chromatography. The higher molecular weight subunit showed; however, qualitative and quantitative differences between the two cell lines: it was expressed in greater quantity on BT-20 cells and its molecular weight was 15 Kd higher. Both subunits could also be identified by immunoblots of BT-20 cells. 相似文献
995.
Janette B Gomos Theresa M Rowe Saumendra N Sarkar Sean P Kessler Ganes C Sen 《Journal of interferon & cytokine research》2002,22(2):199-206
The 9-2 isozyme of 2-5 (A) synthetase has cellular proapoptotic functions that are mediated not by enzyme activity but by the Bcl-2 homology domain 3 present in its unique carboxyl-terminal region. Another proapoptotic cellular protein is Bax, whose absence in the Bax(-/-) mice causes male sterility due to abnormal sperm differentiation. In this study, we examined whether transgenic 9-2 expression can substitute for the in vivo reproductive function of Bax. To achieve this goal, a sperm-specific promoter was used to drive the expression of 9-2 in the sperm of transgenic mice. By selective cross-breeding, the transgene was transferred to Bax(-/-) mice to generate the experimental mouse line (Bax(-/-), 9-2(+/+)). The male experimental mice were sterile, and their testes maintained the structural abnormality found in Bax(-/-) mice. Thus, the male reproduction functions of Bax could not be replaced by the 9-2 isozyme of 2-5 (A) synthetase. 相似文献
996.
With the increased use of indwelling central venous catheters, increasing numbers of cases of Rhodotorula fungemia have been observed in patients with neoplasia and neutropenia. In most patients with catheter-related Rhodotorula fungemia, the condition has been treated with broadspectrum antibiotics. We report two cases of central venous catheter-related
Rhodotorula rubra fungemia that occurred in patients with acute myeloblastic leukemia. Both patients were in a state of neutropenia. One patient
was treated with amphotericin B and his central venous catheter was removed, but he died of Klebsiella pneumoniae bacteremia. The other patient was treated with amphotericin B and discharged, with a central venous catheter, after recovery
from neutropenia. Although the management of catheter-related Rhodotorula fungemia infections remains controversial, resolution of the underlying disease is more important than catheter removal for
recovery from Rhodotorula rubra fungemia.
Received: August 22, 2001 / Accepted: October 8, 2001 相似文献
997.
Hinrich Böhner Detlef Kindgen-Milles Andreas Grust Rolf Buhl Wolf-Christian Lillotte Barbara T. Müller Eckhard Müller Günter Fürst Wilhelm Sandmann 《Langenbeck's archives of surgery / Deutsche Gesellschaft fur Chirurgie》2002,387(1):21-26
BACKGROUND: The efficacy of nasal continuous positive airway pressure (nCPAP) as a prophylactic method for preventing cardiopulmonary complications after major vascular surgery has not been investigated. PATIENTS/METHODS: In a prospective randomized trial, 204 patients undergoing elective midline laparotomy for vascular surgery were randomized to receive standard therapy ( n=105) or additional prophylactic nCPAP ( n=99) for the first postoperative night. Postoperative oxygenation, incidence of severe cardiac, and pulmonary complications, length of intensive care surveillance and length of total postoperative hospital stay (LOS) were compared. RESULTS: Prophylactic nCPAP significantly reduced the number of patients with severe oxygenation disturbances defined as paO(2) < 70 mmHg with FiO(2) > or = 0.7 (5 versus 17, P=.01). There were no differences with respect to death, cardiac and pulmonary complications, length of intensive care surveillance or LOS. CONCLUSION: Prophylactic 12 h nCPAP significantly reduces the occurrence of postoperative oxygenation disturbances but has no effect on cardiac or pulmonary complications, need for intensive care, LOS or mortality after major vascular surgery. 相似文献
998.
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
999.
1000.
Many important pharmaceutical agents, including vancomycin, bleomycin, cyclosporin, and several antibiotics, are produced by non‐ribosomal peptide synthetase (NRPS) enzymes in microorganisms. The NRPS pathway produces an extensive library of products using multienzyme complexes acting in an assembly‐line fashion. Engineering an NRPS system to produce an even greater variety of products, some of which may also have beneficial therapeutic value, would be an enormous advantage. Several approaches have been successful in generating novel NRPS products: mutational biosynthesis during which nonnatural substrates are fed to an organism; domain and module swapping between different species to generate hybrid enzymes; and rational site‐directed mutagenesis, based either on phylogeny or computational prediction, intended to switch substrate specificity and produce altered products. This review will highlight the progress in these areas and describe research in the future that will extend the capacity for re‐engineering NRPS systems. Drug Dev. Res. 66:9–18, 2006. © 2006 Wiley‐Liss, Inc. 相似文献