全文获取类型
收费全文 | 7440篇 |
免费 | 329篇 |
国内免费 | 41篇 |
专业分类
耳鼻咽喉 | 72篇 |
儿科学 | 288篇 |
妇产科学 | 446篇 |
基础医学 | 1231篇 |
口腔科学 | 192篇 |
临床医学 | 551篇 |
内科学 | 1274篇 |
皮肤病学 | 392篇 |
神经病学 | 555篇 |
特种医学 | 394篇 |
外科学 | 946篇 |
综合类 | 90篇 |
一般理论 | 4篇 |
预防医学 | 273篇 |
眼科学 | 180篇 |
药学 | 390篇 |
中国医学 | 1篇 |
肿瘤学 | 531篇 |
出版年
2022年 | 47篇 |
2021年 | 97篇 |
2020年 | 66篇 |
2019年 | 86篇 |
2018年 | 99篇 |
2017年 | 79篇 |
2016年 | 102篇 |
2015年 | 109篇 |
2014年 | 147篇 |
2013年 | 215篇 |
2012年 | 282篇 |
2011年 | 321篇 |
2010年 | 221篇 |
2009年 | 216篇 |
2008年 | 304篇 |
2007年 | 320篇 |
2006年 | 326篇 |
2005年 | 339篇 |
2004年 | 351篇 |
2003年 | 309篇 |
2002年 | 309篇 |
2001年 | 163篇 |
2000年 | 163篇 |
1999年 | 152篇 |
1998年 | 105篇 |
1997年 | 89篇 |
1996年 | 77篇 |
1995年 | 66篇 |
1994年 | 56篇 |
1993年 | 61篇 |
1992年 | 66篇 |
1991年 | 78篇 |
1990年 | 61篇 |
1989年 | 74篇 |
1988年 | 87篇 |
1987年 | 82篇 |
1986年 | 70篇 |
1985年 | 84篇 |
1984年 | 61篇 |
1983年 | 48篇 |
1981年 | 42篇 |
1979年 | 56篇 |
1978年 | 33篇 |
1975年 | 42篇 |
1969年 | 33篇 |
1932年 | 31篇 |
1931年 | 35篇 |
1930年 | 35篇 |
1928年 | 42篇 |
1913年 | 43篇 |
排序方式: 共有7810条查询结果,搜索用时 0 毫秒
101.
Ludwig Waelsch Karl Herxheimer Dr. Victor Bandler Robert Herz 《Archives of dermatological research》1901,56(2):315-320
Ohne Zusammenfassung 相似文献
102.
103.
Daniela Gerges Sebastian Kapps Esperanza Hernndez-Carralero Raimundo Freire Monika Aiad Sophie Schmidt Wolfgang Winnicki Thomas Reiter Sahra Pajenda Alice Schmidt Gere Sunder-Plassmann Ludwig Wagner 《Viruses》2022,14(6)
SARS-CoV-2 variants of concern (VOCs) have caused a significant increase in infections worldwide. Despite high vaccination rates in industrialized countries, the fourth VOC, Omicron, has outpaced the Delta variant and is causing breakthrough infections in individuals with two booster vaccinations. While the magnitude of morbidity and lethality is lower in Omicron, the infection rate and global spread are rapid. Using a specific IgG multipanel-ELISA with the spike protein’s receptor-binding domain (RBD) from recombinant Alpha, Gamma, Delta, and Omicron variants, sera from health-care workers from the Medical University of Vienna were tested pre-pandemic and post-vaccination (BNT162b2; ChAdOx1 nCoV-19). The cohort was continuously monitored by SARS-CoV-2 testing and commercial nucleocapsid IgG ELISA. RBD IgG ELISA showed significantly lower reactivity against the Omicron-RBD compared to the Alpha variant in all individuals (p < 0.001). IgG levels were independent of sex, but were significantly higher in BNT162b2 recipients <45 years of age for Alpha, Gamma, and Delta (p < 0.001; p = 0.040; p = 0.004, respectively). Pre-pandemic cross-reactive anti-Omicron IgG was detected in 31 individuals and was increased 8.78-fold after vaccination, regardless of vaccine type. The low anti-RBD Omicron IgG level could explain the breakthrough infections and their presence could also contribute to a milder COVID-19 course by cross-reactivity and broadening the adaptive immunity. 相似文献
104.
Deborah Bowen Hendrika Meischke Nigel Bush Jean Wooldridge Robert Robbins Abi Ludwig 《Health care for women international》2013,34(10):940-951
A random, population-based sample of 431 women aged 18–74 in King County, Washington, USA, completed a survey module on Internet use and access. Level of mental health, level of general health perceptions, older age, and higher income predicted women's health-related Internet use. Participants without access reported various barriers to obtaining access; perceived lack of usefulness of the Internet as an information source and unfamiliarity with using this technology appear equally important reasons as financial cost for not adopting the Internet. Internet use motivators are complex; these findings have relevance to the design of Internet-based interventions. 相似文献
105.
Research in the field of operations management and medicine analyzed how workload affects productivity and patient outcomes. However, staff quality has largely been neglected, and if staffing information has indeed been included, then it takes the form of quantitative measures like staff–to–patient ratios. We therefore seek to analyze how education and experience are directly associated with effort. How do responses to workload differ with respect to education and experience? By analyzing a single hospital unit, we are able to establish a link between staff quality and patient outcomes, allowing us to demonstrate empirically that knowledge and experience are highly relevant in staff members’ responses to increasing system load. The systematic aligning of staffing with expected system load should therefore consider not only staffing quantity but also staffing quality. Provided with a reliable prediction of system load, this knowledge would allow managers to generate savings since they can assign high-quality staff more effectively. 相似文献
106.
Ludwig Weissbecker MS Robert D. Carpenter BS Peter C. Luchsinger MD Thomas S. Osdene PhD 《Archives of environmental & occupational health》2013,68(5):756-759
A simple, rapid method was developed for the determination of in vitro alveolar macrophage viability after exposure to gases. Air pollutants such as ozone, sulfur dioxide, and oxides of nitrogen killed alveolar macrophages, as determined by the dye exclusion test. Ozone (O3) was effective at very low concentrations. Other gases such as carbon dioxide (CO2), carbon monoxide (CO), methane (CH4), methyl chloride (CH3Cl), acrolein, acetaldehyde, acetone, isoprene, benzene, and hydrocyanic acid (HCN) had no effect on cell viability. 相似文献
107.
Uhlmann D Armann B Ludwig S Escher E Pietsch UC Tannapfel A Teupser D Hauss J Witzigmann H 《The Journal of surgical research》2002,105(2):173-180
BACKGROUND: The University of Wisconsin solution (UW) is the gold standard for pancreas preservation. Celsior (CEL) was formulated specifically for heart preservation. Recently, experimental and clinical experience has been reported on the application of CEL to abdominal organs. In this animal study, pancreas preservation with CEL was compared with that in UW solution. PATIENTS AND MATERIALS: Heterotopic, allogeneic pancreaticoduodenal transplantation was performed in female G?ttingen Minipigs (n = 12 donors, n = 12 recipients). The grafts were flushed and stored for 6 h at 4 degrees C in UW or CEL. The recipients were randomized into two groups receiving either UW (n = 6)- or CEL (n = 6)-preserved grafts with a follow-up of 5 days. Blood flow (laser Doppler), partial oxygen tension, histological changes, endothelin-1 (plasma, immunohistochemistry), lipase, amylase, trypsinogen activation peptide, and C-reactive protein (CRP) were measured. RESULTS: Partial oxygen tension was lower in the CEL group (P < 0.05). However, blood flow did not differ between UW- and CEL-preserved organs. The histomorphologic analysis of the pancreatic grafts revealed significantly less edema in the UW-preserved organs. Serum levels of amylase, lipase, CRP, and TAP taken from the central venous blood were comparable in the two groups, except for higher amylase values 36 h after reperfusion in the CEL group compared to the UW group (P < 0.05). Likewise, TAP taken from the portal venous effluent of the graft was found to be higher in the CEL group than in UW (P < 0.05). Endothelin-1 serum levels rose significantly during reperfusion without differences between the two groups. ET-1 immunohistochemistry revealed increased local ET-1 during reperfusion in all grafts. However, the ET-1 immunostaining in the CEL group was more pronounced than that in the UW group (P < 0.05). CONCLUSIONS: Our results suggest that CEL solution is not as effective in preventing pancreatic ischemia/reperfusion damage as the standard UW solution in experimental pancreas transplantation. Increased ET-1 immunostaining and reduced p(ti)O(2) in the CEL group indicate increased microcirculatory damage in the CEL group. 相似文献
108.
Alport syndrome associated with diffuse leiomyomatosis: COL4A5-COL4A6 deletion associated with a mild form of Alport nephropathy. 总被引:3,自引:0,他引:3
Henning Mothes Laurence Heidet Christelle Arrondel Konrad Klaus Richter Mariana Thiele Ludwig Patzer Yoshikazu Sado Marie-Claire Gubler Corinne Antignac Johannes Scheele 《Nephrology, dialysis, transplantation》2002,17(1):70-74
BACKGROUND: The X-linked Alport syndrome (AS) is an inherited nephropathy due to mutations in the COL4A5 gene, encoding the alpha5 chain of type IV collagen, a major component of the glomerular basement membrane (GBM). Here, we report a new kindred with the rare association of X-linked AS and diffuse leiomyomatosis (DL), which is a tumourous process involving smooth muscle cells of the oesophagus, the tracheobronchial tree and, in females, the genital tract. For this syndrome, an almost constant association of large COL4A5 rearrangements with a severe juvenile form of nephropathy has been described for male patients. METHODS: DNA rearrangement at the COL4A5-COL4A6 locus was studied in several members of this family using polymerase chain reaction and pulsed field gel electrophoresis. Furthermore, immunohistochemical staining of tumour and skin samples was performed. RESULTS: The affected patients in this family carry a 120 kb deletion by which the COL4A5 exon 1 and COL4A6 exons 1, 1', and 2 are removed. Immunohistochemical investigation of a skin biopsy of an affected male patient confirmed the absence of both the alpha5 and the alpha6 chains of type IV collagen in the basement membrane of the skin. Surprisingly, both affected male patients had a rather mild renal phenotype. CONCLUSIONS: This report shows that, contrary to what has been reported to date, patients suffering from AS associated with DL can be associated with a late onset renal failure (adult) form of nephropathy. 相似文献
109.
110.
Image guidance has proven to be an important tool in surgery for deep-seated or eloquently located cavernomas. However, neuronavigation
depending on preoperative images can fail. Thus, the displayed anatomy might be distorted already during the approach. This
report demonstrates the use of three-dimensional intraoperative ultrasound (3D-US) as a rescue tool, when conventional navigation
is erroneous. Two patients with symptomatic cavernomas, the one located subcortically in the right peritrigonum, the other
in the left thalamus, were operated in our clinic via an image-guided approach. An integrated ultrasound-navigation system
was used for neuronavigation. In both cases, navigation based on preoperative MRI failed after the craniotomy because patient-to-image
registration was lost. In both cases, a simple registration of the patient’s orientation was performed. Then a 3D-US volume
was acquired and navigation was performed using the 3D-US data set. This is accurate as image acquisition and navigation are
done in the same system. The cavernoma was visualized without difficulties in both cases. It could be reached directly via
the ultrasound-guided approach. Patients’ symptoms improved postoperatively and a complete resection could be documented.
Two cavernomas were successfully resected using 3D-US guidance. In our experience, stand-alone 3D-US navigation is an effective
option if conventional MRI-based navigation fails. 相似文献