全文获取类型
收费全文 | 36258篇 |
免费 | 3702篇 |
国内免费 | 47篇 |
专业分类
耳鼻咽喉 | 476篇 |
儿科学 | 974篇 |
妇产科学 | 742篇 |
基础医学 | 5207篇 |
口腔科学 | 1364篇 |
临床医学 | 4134篇 |
内科学 | 7234篇 |
皮肤病学 | 401篇 |
神经病学 | 2927篇 |
特种医学 | 1240篇 |
外国民族医学 | 2篇 |
外科学 | 4795篇 |
综合类 | 918篇 |
一般理论 | 30篇 |
预防医学 | 3837篇 |
眼科学 | 1005篇 |
药学 | 2788篇 |
1篇 | |
中国医学 | 27篇 |
肿瘤学 | 1905篇 |
出版年
2021年 | 522篇 |
2020年 | 328篇 |
2019年 | 552篇 |
2018年 | 600篇 |
2017年 | 442篇 |
2016年 | 468篇 |
2015年 | 571篇 |
2014年 | 802篇 |
2013年 | 1199篇 |
2012年 | 1665篇 |
2011年 | 1755篇 |
2010年 | 933篇 |
2009年 | 914篇 |
2008年 | 1539篇 |
2007年 | 1640篇 |
2006年 | 1506篇 |
2005年 | 1575篇 |
2004年 | 1431篇 |
2003年 | 1377篇 |
2002年 | 1350篇 |
2001年 | 1092篇 |
2000年 | 1151篇 |
1999年 | 1066篇 |
1998年 | 379篇 |
1997年 | 308篇 |
1996年 | 353篇 |
1995年 | 333篇 |
1994年 | 326篇 |
1993年 | 325篇 |
1992年 | 854篇 |
1991年 | 835篇 |
1990年 | 861篇 |
1989年 | 769篇 |
1988年 | 728篇 |
1987年 | 729篇 |
1986年 | 688篇 |
1985年 | 702篇 |
1984年 | 525篇 |
1983年 | 482篇 |
1982年 | 300篇 |
1981年 | 313篇 |
1980年 | 284篇 |
1979年 | 469篇 |
1978年 | 376篇 |
1977年 | 301篇 |
1976年 | 281篇 |
1974年 | 374篇 |
1973年 | 361篇 |
1972年 | 297篇 |
1971年 | 311篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Rebecca M. Schwartz PhD Edmond S. Malka Michael Augenbraun Steven Rubin Matthew Hogben Nicole Liddon William M. McCormack Tracey E. Wilson 《Journal of urban health》2006,83(6):1095-1104
Efforts to control chlamydial and gonococcal infections include notifying eligible sexual partners of possible infection,
primarily by asking the diagnosed patient to notify their partners. This approach, known as patient referral, is widely used
but poorly understood. The current study examined psychosocial and cognitive factors associated with patient referral among
an urban, minority sample of 168 participants recently diagnosed with Chlamydia trachomatis or Neisseria gonorrhoeae. At a follow-up interview 1-month from diagnosis, participants were more likely to have notified all eligible partners if
they had greater intention to notify at baseline (OR = 3.72; 95% CI = 1.34, 10.30) and if they had only one partner at baseline
(OR = 4.08; 95% CI = 1.61, 10.31). There were also gender differences as well as differences based on type of partner (i.e.,
regular, casual, one-time). The implications of these findings for the design of programs to promote patient referral for
sexually transmitted infections are discussed.
Schwartz, Malka, Augenbraun, McCormack, and Wilson are with the State University of New York, Downstate Medical Center, Brooklyn,
NY, USA; Rubin is with the New York City Department of Health, Bureau of STD Control, New York, NY, USA; Rubin, Hogben, and
Liddon are with the Centers for Disease Control and Prevention, Atlanta, GA, USA; Schwartz is with the Department of Preventive
Medicine and Community Health, SUNY Downstate Medical Center, Box 1240, 450 Clarkson Avenue, Brooklyn, NY 11203, USA. 相似文献
72.
73.
The aim of the present study was to determine whether patients with bronchiectasis and nontuberculous mycobacteria (NTM) have a higher prevalence of Aspergillus-related lung disease. A series of 30 consecutive patients with bronchiectasis and NTM (cases) were compared with 61 patients with bronchiectasis and no evidence of NTM (controls). Aspergillus serology and computerised tomography of the thorax were used to identify Aspergillus-related lung diseases, including aspergilloma, allergic bronchopulmonary aspergillosis and chronic necrotising pulmonary aspergillosis. The rate of positive Aspergillus serology was higher in cases with NTM disease compared with controls (10 out of 30 versus six out of 61). The radiological features of Aspergillus-related lung disease were also more common among patients with NTM disease than controls (six out of 30 versus none out of 61). This association between NTM disease and Aspergillus-related lung disease remained significant after adjustment for confounding effects of age and lung function (adjusted odds ratio 5.1, 95% confidence interval 1.5-17.0). Patients with bronchiectasis and nontuberculous mycobacterial disease have a higher prevalence of coexisting Aspergillus-related lung disease than patients with bronchiectasis and without nontuberculous mycobacteria. Identification of Aspergillus-related lung disease is important as prognosis amongst undetected cases is invariably poor. 相似文献
74.
75.
Alveolar hydatid disease. Review of the surgical experience in 42 cases of active disease among Alaskan Eskimos. 总被引:7,自引:0,他引:7
下载免费PDF全文
![点击此处可从《Annals of surgery》网站下载免费的PDF全文](/ch/ext_images/free.gif)
OBJECTIVE: The authors reviewed the pathophysiology and clinical management of endemic alveolar hydatid disease in Alaskan Eskimos, incorporating recent developments in diagnosis and treatment. SUMMARY BACKGROUND DATA: Alveolar hydatid disease is a highly lethal zoonotic infection caused by the larval stage of Echinococcus multilocularis. This cestode is restricted geographically to northern climates, where foxes and small rodents represent the natural hosts. Domestic dogs also may serve as definitive hosts, and thus, transmit the parasite to humans. Human infection is characterized by the development of a cancer-like hepatic mass, which may extend to adjacent structures or metastasize to distant sites. If the infection goes untreated, mortality reaches 80%. METHODS: The medical records of all patients with alveolar hydatid disease diagnosed or treated at the Alaska Native Medical Center between 1951 and 1993 were reviewed. Forty-two cases of active disease are presented. RESULTS: Nine patients underwent resection of hepatic lesions with intent to cure, and each had a favorable result. Average post-diagnosis survival of those patients was 22 years; six still are living and free of disease. Partial resections or drainage procedures were performed in ten patients. Chemotherapy was used to augment the surgical treatment of eight patients, and four received chemotherapy alone, resulting in improved outcomes compared with historic controls. Late complications included hepatic abscess, biliary obstruction, and portal venous hypertension. CONCLUSIONS: Whereas alveolar hydatid disease rarely is encountered in other areas of North America, the biologic potential for spread of the disease may be increasing because of illegal importation of infected foxes to the Eastern seaboard. Therefore, the surgical community should maintain an awareness of the diagnosis and management of this potentially devastating parasitic infection. 相似文献
76.
The cytotoxicity of the anti-leukaemia drug amsacrine (m-AMSA) has been suggested to result from its oxidative metabolism to the corresponding quinonediimine, N1'-methanesulphonyl-N4'-(9-acridinyl)-3'-methoxy-2',5'-cyclohexad iene-1',4'- diimine (mAQDI). The metabolic fate of mAQDI was examined in cultured CHO cells (subline AA8) to identify the end products to be expected following oxidative metabolism of m-AMSA. [Acridinyl-G-3H]-m-AQDI was rapidly accumulated by AA8 cells in phosphate buffered saline with complete conversion in less than one minute to m-AMSA, macromolecular adducts and polar low molecular weight species, each of these three classes being formed in approximately equal amounts. Two of the polar products were chromatographically identical to those formed on reaction of m-AQDI with reduced glutathione. These were identified by 1H NMR spectroscopy as the 1,4-addition product 5'-(S-glutathionyl)-m-AMSA and the previously unreported isomeric 6'-(S-glutathionyl)-m-AMSA. These thiol adducts were also formed rapidly from m-AQDI in deproteinized cell lysates indicating a non-enzymatic process, although the possibility of enzymatic catalysis in intact cells has not been eliminated. The absence of such products in AA8 cells after treatment with m-AMSA places an upper limit of 1% per hour on the rate of its oxidative metabolism in these cells and suggests that generation of m-AQDI is unlikely to be responsible for the cytotoxicity of m-AMSA in cultured tumour cells. 相似文献
77.
Magnetic resonance imaging of nonmetallic orbital foreign bodies 总被引:2,自引:0,他引:2
W B Wilson J N Dreisbach D E Lattin J C Stears 《American journal of ophthalmology》1988,105(6):612-617
We studied a cadaver head model in which we inserted three orbital foreign bodies. We chose these foreign bodies because of their similarity to substances found in orbital trauma. Teflon and Lucite were used to represent synthetic materials, and dry pine was chosen as a type of organic material. Lucite is similar in radiographic density to plastics used in interior trim for automobiles and spectacle frames. While both orbital ultrasound and plain skull films failed to detect the foreign bodies consistently, both computed tomography and magnetic resonance imaging detected and localized the foreign bodies relatively well. Computed tomography was better in delineating shape and characterizing composition. 相似文献
78.
79.
80.
Using a simplified procedure, we have extracted DNA from unstained paraffin sections of needle biopsies of kidney and liver transplants and identified the presence of CMV using the polymerase chain reaction. This method utilizes oligonucleotide primers for two genes shown to be specific for cytomegalovirus (CMV) as well as an internal control gene (hemoglobin) in a single reaction. Utilizing nested PCR amplification with agarose gel electrophoresis, CMV can be detected without radioisotopes to a level of sensitivity equivalent to one one-hundredth of a cytomegalic virocyte per cm2 of a 3-microM paraffin section. This method is applicable to situations where only scarce paraffin-embedded tissue is available. 相似文献