全文获取类型
收费全文 | 19792篇 |
免费 | 1282篇 |
国内免费 | 43篇 |
专业分类
耳鼻咽喉 | 161篇 |
儿科学 | 498篇 |
妇产科学 | 528篇 |
基础医学 | 2517篇 |
口腔科学 | 377篇 |
临床医学 | 2087篇 |
内科学 | 4379篇 |
皮肤病学 | 364篇 |
神经病学 | 1962篇 |
特种医学 | 695篇 |
外科学 | 2885篇 |
综合类 | 337篇 |
一般理论 | 17篇 |
预防医学 | 1558篇 |
眼科学 | 361篇 |
药学 | 1272篇 |
中国医学 | 19篇 |
肿瘤学 | 1100篇 |
出版年
2023年 | 118篇 |
2022年 | 150篇 |
2021年 | 336篇 |
2020年 | 239篇 |
2019年 | 313篇 |
2018年 | 386篇 |
2017年 | 268篇 |
2016年 | 287篇 |
2015年 | 327篇 |
2014年 | 472篇 |
2013年 | 959篇 |
2012年 | 1127篇 |
2011年 | 1225篇 |
2010年 | 653篇 |
2009年 | 592篇 |
2008年 | 1117篇 |
2007年 | 1191篇 |
2006年 | 1173篇 |
2005年 | 1093篇 |
2004年 | 991篇 |
2003年 | 955篇 |
2002年 | 935篇 |
2001年 | 328篇 |
2000年 | 326篇 |
1999年 | 318篇 |
1998年 | 227篇 |
1997年 | 186篇 |
1996年 | 180篇 |
1995年 | 166篇 |
1994年 | 163篇 |
1993年 | 159篇 |
1992年 | 288篇 |
1991年 | 247篇 |
1990年 | 220篇 |
1989年 | 235篇 |
1988年 | 237篇 |
1987年 | 207篇 |
1986年 | 228篇 |
1985年 | 225篇 |
1984年 | 245篇 |
1983年 | 206篇 |
1982年 | 172篇 |
1981年 | 148篇 |
1980年 | 150篇 |
1979年 | 102篇 |
1978年 | 108篇 |
1977年 | 105篇 |
1976年 | 106篇 |
1974年 | 105篇 |
1973年 | 87篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
A case with a fatal outcome caused by infection with Fusobacterium species was seen in a patient recently operated on for heavy snoring with uvulo-palato-pharyngoplasty (UPPP). The mechanism of infection is discussed. It is concluded that a febrile episode seen in patients less than 2 weeks postoperatively should be considered a serious symptom and be treated intensively after thorough examination. © 1994 John Wiley & Sons, Inc. 相似文献
32.
Yueh-Wei Liu Allan M Concejero Chao-Long Chen Yu-Fan Cheng Hock-Liew Eng Tung-Liang Huang Tai-Yi Chen Chih-Chi Wang Shih-Ho Wang Chih-Che Lin Chee-Chien Yong Chin-Hsiang Yang Amornetta P Jordan Bruno Jawan 《Liver transplantation》2007,13(11):1545-1551
A pseudotumor, giant regenerative nodule, or macroregenerative nodule is an unusual benign hepatic lesion in biliary atresia (BA) patients. This tumor may mimic malignant transformation and may preclude liver transplantation (LT). The clinical and imaging surveillance of patients after the Kasai procedure is therefore an important aspect of management of BA patients. Our objective is to report our experience and describe the incidence, imaging, and pathologic features of pseudotumors in BA patients awaiting LT. From August 1990 to December 2006, 133 LTs for BA were performed. Five (3.8%; 4 female, 1 male) patients were diagnosed with pseudotumor. The patients' records were reviewed. The diagnostic imaging modalities used were abdominal ultrasound (US), computed tomography (CT) scan, and magnetic resonance imaging (MRI). Histologic confirmation of the lesions was obtained in all cases. All underwent the Kasai operation in early infancy. Six of 7 lesions in 4 of 5 patients were demonstrated by pretransplant imaging. Two of 7 tumors were detected by US. Five of 7 lesions were detected by CT, and 5 of 7 lesions were demonstrated by MRI. In 1 patient, the lesion was not seen in the US, CT, or MRI but was found during surgery and confirmed by histology. An additional tumor was found incidentally during histologic examination in a patient previously diagnosed to have 2 tumors by CT and MRI. In another patient diagnosed to have 2 tumors on imaging, pathology revealed only a single tumor. In conclusion, although unusual, pseudotumor should be included in the differential diagnosis of liver masses in BA children. 相似文献
33.
Martin Eefsen Allan Rasmussen Hans Christian Wulf Axel Brock Bent Adel Hansen 《Liver transplantation》2007,13(5):655-657
Erythropoietic protoporphyria (EPP) is a disease of the heme metabolism due to a deficiency of ferrochelatase, leading to accumulation of protoporphyrin (PPIX) in the erythrocyte (red blood cell [RBC]). The major clinical manifestation in EPP is photosensitivity; however, in a small number of patients liver failure is a significant complication and liver transplantation is the only treatment option. Damage to both abdominal skin and organs occurs when exposed to operating light; however, this problem can be ameliorated by the use of filters that block the transmission of light with wavelength below 470 nm. A more unusual but very serious complication postoperatively is severe motor neuropathy, with few or no known acute available precautions. An effective treatment option is needed to manage EPP crises and to prevent complications after liver transplantation. We successfully treated a patient with EPP-induced liver failure with the molecular adsorbents recirculating system (MARS) and Prometheus in independent sessions. Following treatment with MARS we found a 9.1% reduction of the RBC-PPIX concentration and a 5.9% reduction after treatment with the Prometheus system. Plasmapheresis made a reduction in RBC-PPIX concentration of 0.8%. Following treatment sessions with MARS and Prometheus, the clinical condition was markedly improved and orthotopic liver transplantation was performed without further complications. In conclusion, extracorporeal therapy with MARS or Prometheus seems to be efficient in reducing RBC-PPIX concentration in comparison to plasma exchange. 相似文献
34.
35.
Peter Rasmussen Ellen A Dawson Lars Nybo Johannes J van Lieshout Niels H Secher Albert Gjedde 《Journal of cerebral blood flow and metabolism》2007,27(5):1082-1093
Brain function requires oxygen and maintenance of brain capillary oxygenation is important. We evaluated how faithfully frontal lobe near-infrared spectroscopy (NIRS) follows haemoglobin saturation (SCap) and how calculated mitochondrial oxygen tension (PMitoO2) influences motor performance. Twelve healthy subjects (20 to 29 years), supine and seated, inhaled O2 air-mixtures (10% to 100%) with and without added 5% carbon dioxide and during hyperventilation. Two measures of frontal lobe oxygenation by NIRS (NIRO-200 and INVOS) were compared with capillary oxygen saturation (SCap) as calculated from the O2 content of brachial arterial and right internal jugular venous blood. At control SCap (78%+/-4%; mean+/-s.d.) was halfway between the arterial (98%+/-1%) and jugular venous oxygenation (SvO2; 61%+/-6%). Both NIRS devices monitored SCap (P<0.001) within approximately 5% as SvO2 increased from 39%+/-5% to 79%+/-7% with an increase in the transcranial ultrasound Doppler determined middle cerebral artery flow velocity from 29+/-8 to 65+/-15 cm/sec. When SCap fell below approximately 70% with reduced flow and inspired oxygen tension, PMitoO2 decreased (P<0.001) and brain lactate release increased concomitantly (P<0.001). Handgrip strength correlated with the measured (NIRS) and calculated capillary oxygenation values as well as with PMitoO2 (r>0.74; P<0.05). These results show that NIRS is an adequate cerebral capillary-oxygenation-level-dependent (COLD) measure during manipulation of cerebral blood flow or inspired oxygen tension, or both, and suggest that motor performance correlates with the frontal lobe COLD signal. 相似文献
36.
Laurence J Kirmayer Morton Weinfeld Giovani Burgos Guillaume Galbaud du Fort Jean-Claude Lasry Allan Young 《Revue canadienne de psychiatrie》2007,52(5):295-304
OBJECTIVE: Research in the United States tends to attribute low rates of use of mental health services by immigrants to economic barriers. The purpose of our study was to examine this issue in the context of Canada's universal health care system. METHODS: A survey of the catchment area of a comprehensive clinic in Montreal interviewed random samples of 924 Canadian-born individuals and 776 immigrants born in the Caribbean (n = 264), Vietnam (n = 234), or the Philippines (n = 278) to assess their health care use for somatic symptoms, psychological distress, and recent life events. RESULTS: Overall rates of use of medical services in the past year were similar in immigrant (78.5%) and nonimmigrant (76.5%) groups. Rates of use of health care services for psychological distress were significantly lower among immigrants (5.5% compared with 14.7%, P < 0.001). This difference was attributable both to a lower rate of use of specialty mental health services by immigrants (2.5% compared with 11.7%, P < 0.001) and to differential use of medical services for psychological distress (3.5% compared with 5.8%, P = 0.02). When level of psychological distress was controlled, Vietnamese and Filipino immigrants were one-third as likely as Canadian-born residents to make use of mental health services. The lower rate of use by immigrants could not be explained by differences in sociodemographics, somatic or psychological symptoms, length of stay in Canada, or use of alternative sources of help. CONCLUSION: Immigrant status is associated with lower rates of use of mental health services, even with universal health insurance. This lower rate of use likely reflects cultural and linguistic barriers to care. 相似文献
37.
R. Parker Ward Mouaz H. Al-Mallah Gabriel B. Grossman Christopher L. Hansen Robert C. Hendel Todd C. Kerwin Benjamin D. McCallister Rupa Mehta Donna M. Polk Peter L. Tilkemeier Aseem Vashist Kim Allan Williams David G. Wolinsky Edward P. Ficaro 《Journal of nuclear cardiology》2007,14(6):e26-e38
Conclusion The ACCF/ASNC AC for SPECT MPI provides recommendations for the appropriate use of SPECT MPI. After the publication of the
AC document in 2005, the AC has been used by nuclear cardiology practices with many clinical studies evaluating the list of
indications in routine clinical practice. From these data. ASNC recommends minor but important changes to the indication list,
suggesting the addition of 6 new indications and the modification of the definitions for “chest pain syndrome” and “CHD high
risk.”. An objective review of existing indications focused on only those indications that had significant variability among
the reviewers (n=20). These indications were reviewed in the presence of existing and new evidence-based data, and ASNC recommends
that the grades for 6 indications be re-evaluated.
The AC for SPECT MPI will require periodic review as new evidence becomes available or as clinical practice evolves. ASNC
recognizes the importance of these criteria to improve the quality of patient care, and it will continue to play a key role
in assembling the information for this ongoing review. From the current summary of evidence, ASNC consensus opinions, and
ASNC recommendations in this document, ASNC strongly recommends that the AC guidelines be reviewed
Prepared by the American Society of Nuclear Cardiology Quality Assurance Subcommittee for Quality in Imaging Standards.
Reviewed by members of the American Society of Nuclear Cardiology Quality Assurance Committee.
Approved by the American Society of Nuclear Cardiology Board of Directors, September 6, 20. 相似文献
38.
39.
40.
Echocardiographic detection of congenital heart disease in the fetus: present and future. 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Heart (British Cardiac Society)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
L. D. Allan 《Heart (British Cardiac Society)》1995,74(2):103-106