全文获取类型
收费全文 | 16488篇 |
免费 | 1065篇 |
国内免费 | 54篇 |
专业分类
耳鼻咽喉 | 148篇 |
儿科学 | 590篇 |
妇产科学 | 365篇 |
基础医学 | 2487篇 |
口腔科学 | 346篇 |
临床医学 | 1937篇 |
内科学 | 3383篇 |
皮肤病学 | 276篇 |
神经病学 | 1601篇 |
特种医学 | 503篇 |
外国民族医学 | 3篇 |
外科学 | 2169篇 |
综合类 | 111篇 |
一般理论 | 9篇 |
预防医学 | 1388篇 |
眼科学 | 246篇 |
药学 | 908篇 |
中国医学 | 15篇 |
肿瘤学 | 1122篇 |
出版年
2023年 | 118篇 |
2022年 | 132篇 |
2021年 | 314篇 |
2020年 | 237篇 |
2019年 | 313篇 |
2018年 | 405篇 |
2017年 | 318篇 |
2016年 | 330篇 |
2015年 | 370篇 |
2014年 | 481篇 |
2013年 | 701篇 |
2012年 | 978篇 |
2011年 | 1020篇 |
2010年 | 552篇 |
2009年 | 495篇 |
2008年 | 935篇 |
2007年 | 977篇 |
2006年 | 886篇 |
2005年 | 912篇 |
2004年 | 820篇 |
2003年 | 760篇 |
2002年 | 717篇 |
2001年 | 360篇 |
2000年 | 291篇 |
1999年 | 303篇 |
1998年 | 190篇 |
1997年 | 181篇 |
1996年 | 141篇 |
1995年 | 126篇 |
1994年 | 95篇 |
1993年 | 97篇 |
1992年 | 157篇 |
1991年 | 157篇 |
1990年 | 172篇 |
1989年 | 177篇 |
1988年 | 145篇 |
1987年 | 148篇 |
1986年 | 153篇 |
1985年 | 163篇 |
1984年 | 142篇 |
1983年 | 116篇 |
1982年 | 61篇 |
1981年 | 70篇 |
1980年 | 77篇 |
1979年 | 108篇 |
1978年 | 81篇 |
1977年 | 65篇 |
1974年 | 72篇 |
1972年 | 73篇 |
1970年 | 57篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Antonia Zapf Marianne Huebner Geraldine Rauch Meinhard Kieser 《Statistics in medicine》2019,38(4):695-701
Biostatisticians play an important role in medical research. They are co-responsible for an appropriate and efficient study design, they are involved in monitoring the study conduct, they plan and perform the data analysis, and they are involved in interpreting and publishing the results. However, how are the biostatisticians prepared for their tasks and responsibilities? Graduate programs in biostatistics are being offered, but some practicing biostatisticians completed their studies in a mathematical or epidemiological program, or obtained their degree in subject-specific fields (such as medicine or biology). Therefore, the expertise and the competencies can vary widely between the individual biostatisticians, also depending on the application field. In this article, focusing on European and US practices, we discuss the required professional expertise for the main areas of applications in the medical field as well as the necessary soft skill competencies of a biostatistician. 相似文献
2.
3.
Marie Warrer Petersen Tine Sylvest Meyhoff Marie Helleberg Maj-Brit Nørregaard Kjær Anders Granholm Carl Johan Steensen Hjortsø Thomas Steen Jensen Morten Hylander Møller Peter Buhl Hjortrup Mik Wetterslev Gitte Kingo Vesterlund Lene Russell Vibeke Lind Jørgensen Klaus Tjelle Thomas Benfield Charlotte Suppli Ulrik Anne Sofie Andreasen Thomas Mohr Morten H. Bestle Lone Musaeus Poulsen Mette Friberg Hitz Thomas Hildebrandt Lene Surland Knudsen Anders Møller Christoffer Grant Sølling Anne Craveiro Brøchner Bodil Steen Rasmussen Henrik Nielsen Steffen Christensen Thomas Strøm Maria Cronhjort Rebecka Rubenson Wahlin Stephan Jakob Luca Cioccari Balasubramanian Venkatesh Naomi Hammond Vivekanand Jha Sheila Nainan Myatra Christian Gluud Theis Lange Anders Perner 《Acta anaesthesiologica Scandinavica》2020,64(9):1365-1375
Introduction
Severe acute respiratory syndrome coronavirus-2 has caused a pandemic of coronavirus disease (COVID-19) with many patients developing hypoxic respiratory failure. Corticosteroids reduce the time on mechanical ventilation, length of stay in the intensive care unit and potentially also mortality in similar patient populations. However, corticosteroids have undesirable effects, including longer time to viral clearance. Clinical equipoise on the use of corticosteroids for COVID-19 exists.Methods
The COVID STEROID trial is an international, randomised, stratified, blinded clinical trial. We will allocate 1000 adult patients with COVID-19 receiving ≥10 L/min of oxygen or on mechanical ventilation to intravenous hydrocortisone 200 mg daily vs placebo (0.9% saline) for 7 days. The primary outcome is days alive without life support (ie mechanical ventilation, circulatory support, and renal replacement therapy) at day 28. Secondary outcomes are serious adverse reactions at day 14; days alive without life support at day 90; days alive and out of hospital at day 90; all-cause mortality at day 28, day 90, and 1 year; and health-related quality of life at 1 year. We will conduct the statistical analyses according to this protocol, including interim analyses for every 250 patients followed for 28 days. The primary outcome will be compared using the Kryger Jensen and Lange test in the intention to treat population and reported as differences in means and medians with 95% confidence intervals.Discussion
The COVID STEROID trial will provide important evidence to guide the use of corticosteroids in COVID-19 and severe hypoxia.4.
5.
Andreas Lange Claudia Kistler Tanja B. Jutzi Alexandr V. Bazhin Claus Detlev Klemke Dirk Schadendorf Stefan B. Eichmüller 《Experimental dermatology》2009,18(6):527-535
Abstract: The identification of tumor-specific proteins located at the plasma membrane is hampered by numerous methodological pitfalls many of which are associated with the post-translational modification of such proteins. Here, we present a new combination of detergent fractionation of cells and of subtractive suppression hybridization (SSH) to gain overexpressed genes coding for membrane-associated or secreted proteins. Fractionation of subcellular components by digitonin allowed sequestering mRNA of the rough Endoplasmatic reticulum and thereby increasing the percentage of sequences coding for membrane-bound proteins. Fractionated mRNAs from the cutaneous T-cell lymphoma (CTCL) cell line HuT78 and from normal peripheral blood monocytes were used for SSH leading to the enrichment of sequences overexpressed in the tumor cells. We identified some 21 overexpressed genes, among them are GPR137B, FAM62A, NOMO1, HSP90, SLIT1, IBP2, CLIF, IRAK and ARC. mRNA expression was tested for selected genes in CTCL cell lines, skin specimens and peripheral blood samples from CTCL patients and healthy donors. Several of the detected sequences are clearly related to cancer, but have not yet been associated with CTCL. qPCR confirmed an enrichment of these mRNAs in the rough endoplasmic reticulum fraction. RT-PCR confirmed the expression of these genes in skin specimens and peripheral blood of CTCL patients. Western blotting verified protein expression of HSP90 and IBP2 in HuT78. GPR137B could be detected by immunohistology in HuT78 and in keratinocytes of dysplastic epidermis, but also in sweat glands of healthy skin. In summary, we developed a new technique, which allows identifying overexpressed genes coding preferentially for membrane-associated proteins. 相似文献
6.
Signe S?nderkaer Marianne Schmiegelow Henrik Carstensen Lars B?geskov Nielsen J?rn Müller Kjeld Schmiegelow 《Journal of clinical oncology》2003,21(7):1347-1351
PURPOSE: To evaluate the pattern of neurological late effects in patients who have received surgery only for a brain tumor in childhood and to identify possible risk factors for neurological sequelae. PATIENTS AND METHODS: The medical, histologic, and operative records were reviewed for 65 consecutive patients operated for a benign brain tumor from 1970 to 1997, and all patients were re-examined after a median length of follow-up of 10.7 years. Thirty-four patients had posterior fossa tumors, 22 patients had cerebral hemisphere tumors, and nine patients had midline tumors. RESULTS: At the time of follow-up, 20 patients (31%) had no neurological deficits, 22 patients (34%) had minor deficits that did not interfere with their daily life activities, and 23 patients (35%) had moderate or severe deficits such as severe ataxia, spastic paresis, seriously reduced vision, or epilepsy with more than two seizures per year. Fourteen of the 31 patients (45%) registered with ataxia preoperatively had recovered fully. Six of seven patients had persistence of a pre- or postoperatively developed hemiparesis. Thirteen of 23 patients had persistence of cranial nerve deficits that developed second to surgery. Fifty-five percent of the 18 patients with seizures at diagnosis were seizure-free at follow-up. At follow-up both ataxia and hemiparesis were significantly more frequent among females (P =.02 and P =.03, respectively). CONCLUSION: In patients who received operation as the only treatment for their brain tumor, there was a good chance of total or partial recovery of preoperative and postoperative neurological deficits, although only one third of the patients will have no long-term neurological deficits. 相似文献
7.
8.
Udo Lorenz Marianne Abele-Horn Dieter Bussen Arnulf Thiede 《Langenbeck's archives of surgery / Deutsche Gesellschaft fur Chirurgie》2007,392(6):761-765
Background To our best knowledge, Panton–Valentine leucocidin (PVL)-positive methicillin-sensitive Staphylococcus aureus (MSSA) has not been described yet as cause for severe pyomyositis.
Case report We present a 23-year-old apparently healthy male patient without any typical predisposing findings who developed severe pyomyositis
secondary to an operated pilonidal cyst. In the follow-up, the patient showed signs of immunocompromisation. The causative
agent for purulent infection of multiple muscles was a MSSA strain harbouring PVL toxin.
Results In the reported case, aggressive antibiotic and surgical treatment with additional application of immunoglobulins has lead
to recovery from the disease without relapse.
Conclusions PVL-positive S. aureus are associated with skin diseases, multiple abscesses and often complicated by severe sepsis and necrotising pneumonia. Under
such circumstances, the mortality rate can reach up to 75%. In addition, the PVL toxin can cause immunocompromisation and
might be therefore involved in the aetiology of pyomyositis. Aggressive antibiotic and surgical treatment with additional
application of immunoglobulins is recommended for treatment. 相似文献
9.
Jan de Lange Thomas Putters Erik M Baas Johan M van Ingen 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,104(6):841-845
OBJECTIVE: The purpose of this study was to evaluate the potential benefit of an ultrasonic device in apical surgery on the outcome of treatment. STUDY DESIGN: A randomized prospective design was used in a standardized treatment protocol. Patients were allocated to treatment with an ultrasonic device (P-Max Newtron) or treatment with a bur in an otherwise similar protocol. One year after treatment the results were evaluated by 2 oral and maxillofacial surgeons who were blinded for the therapy. RESULTS: Out of a total group of 399 patients who were included in the study, adequate follow-up could be obtained in 290 patients. The overall success rate in the ultrasonic group was 80.5% and in the group treated with a bur 70.9% (P = .056). In molars, the difference in success rate was significant (P = .02). CONCLUSION: The use of an ultrasonic device in apical surgery improved the outcome of treatment. In molars this effect was significant. 相似文献
10.
Ventilation imaging of the lung: Comparison of hyperpolarized helium-3 MR imaging with Xe-133 scintigraphy 总被引:1,自引:0,他引:1
Talissa A. Altes MD Patrice K. Rehm MD Frank Harrell PhD Michael Salerno PhD Thomas M. Daniel MD Eduard E. de Lange MD 《Academic radiology》2004,11(7):729-734
RATIONALE AND OBJECTIVES: To compare hyperpolarized helium-3 (HHe) magnetic resonance imaging (MRI) of the lung with standard Xe-133 lung ventilation scintigraphy. MATERIALS AND METHODS: We performed a retrospective review of 15 subjects who underwent HHe MRI and Xe-133 lung ventilation imaging. Coronal MRI sections were acquired after a single inhalation of HHe gas, and standard posterior planar lung ventilation scintigraphy was performed during continuous breathing of Xe-133 gas. The first breath scintigram of each patient was compared with a composite MR image composed of the sum of the individual MR images and with the individual helium-3 MR images. Ventilation defects on the two imaging modalities were compared for size, conspicuity, and concordance in presence and location. Assessment was done separately for each of four lung quadrants. RESULTS: Comparing the composite HHe MR images with Xe-133 scintigraphy, ventilation defect size, conspicuity and concordance were the same in 67% (40/60), 63% (38/60), and 62% (37/60) quadrants, respectively. Comparing the individual HHe MR image sections with the Xe-133 ventilation scan, there was concordance between the ventilation defects in 27% (16/60) of quadrants. More defects were identified on the individual HHe MR images in 62% (37/60) of quadrants. CONCLUSION: There was good agreement between composite HHe MR image and first breath Xe-133 scintigraphic images, supporting the widely held assumption that HHe MRI likely depicts first breath lung ventilation. 相似文献