全文获取类型
收费全文 | 11790篇 |
免费 | 821篇 |
国内免费 | 52篇 |
专业分类
耳鼻咽喉 | 82篇 |
儿科学 | 231篇 |
妇产科学 | 184篇 |
基础医学 | 1748篇 |
口腔科学 | 265篇 |
临床医学 | 1172篇 |
内科学 | 2342篇 |
皮肤病学 | 298篇 |
神经病学 | 1138篇 |
特种医学 | 707篇 |
外国民族医学 | 2篇 |
外科学 | 2242篇 |
综合类 | 41篇 |
一般理论 | 2篇 |
预防医学 | 470篇 |
眼科学 | 252篇 |
药学 | 731篇 |
中国医学 | 17篇 |
肿瘤学 | 739篇 |
出版年
2023年 | 87篇 |
2022年 | 188篇 |
2021年 | 433篇 |
2020年 | 233篇 |
2019年 | 282篇 |
2018年 | 354篇 |
2017年 | 262篇 |
2016年 | 412篇 |
2015年 | 448篇 |
2014年 | 517篇 |
2013年 | 603篇 |
2012年 | 920篇 |
2011年 | 886篇 |
2010年 | 528篇 |
2009年 | 494篇 |
2008年 | 737篇 |
2007年 | 687篇 |
2006年 | 622篇 |
2005年 | 580篇 |
2004年 | 477篇 |
2003年 | 474篇 |
2002年 | 364篇 |
2001年 | 147篇 |
2000年 | 141篇 |
1999年 | 143篇 |
1998年 | 91篇 |
1997年 | 69篇 |
1996年 | 42篇 |
1995年 | 46篇 |
1994年 | 39篇 |
1992年 | 80篇 |
1991年 | 68篇 |
1990年 | 79篇 |
1989年 | 58篇 |
1988年 | 50篇 |
1987年 | 57篇 |
1986年 | 55篇 |
1985年 | 67篇 |
1984年 | 44篇 |
1983年 | 38篇 |
1981年 | 33篇 |
1979年 | 39篇 |
1978年 | 36篇 |
1977年 | 37篇 |
1976年 | 40篇 |
1975年 | 33篇 |
1973年 | 37篇 |
1971年 | 34篇 |
1970年 | 32篇 |
1969年 | 33篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
41.
W. B. Spatz R.-B. Illing D. M. Vogt Weisenhorn 《The Journal of comparative neurology》1994,339(4):519-534
The anatomical distributions of the mitochondrial enzyme cytochrome oxidase (CO) and of the calcium binding protein parvalbumin (PV) were studied in the striate cortex of adult and neonate New World monkeys (Callithrix jacchus). In the adult marmoset, both proteins were found in laminar arrangements similar to those described for the macaque monkey, with prominent bands of PV-like immunoreactive (PV-LI) puncta in layers IV and IIIb, and fairly evenly distributed PV-LI nonpyramidal neurons. Furthermore, the pattern of CO activity in area 17 of the neonate marmoset was almost identical to the CO pattern described in neonate macaque and squirrel monkeys. It came, therefore, as a surprise to find that the adult pattern of PV-like immunoreactivity (PV-LI) in the marmoset striate cortex arises from a neonatal pattern strikingly different from that seen in any developmental stage of the macaque, or in any other mammal studied so far. In the deep layers IV through VI of the neonate marmoset, a large number of PV-LI neurons was stained in bandlike patterns, their number in layers IV and V exceeding the number of PV-LI neurons present in these layers of the adult marmoset area 17. Staining of layers IV and VI was restricted to area 17 and involved nonpyramidal cells and their exceeding the number of PV-LI neurons present in these layers of the adult marmoset area 17. Staining of layers IV and VI was restricted to area 17 and involved nonpyramidal cells and their processes. The stained band of layer V, in contrast, continued throughout most of the neocortex. In area 17, an estimated 10 to 20% of the stained cells in layer V exhibited pyramidal shapes. The findings show that the expression of PV by visual cortical cells occurs before birth and suggest that the comparatively early onset of PV expression is not dependent on the onset of textured vision. The exuberant number of stained cells in some layers, and particularly the staining of pyramidal cells, in the neonate marmoset, suggest that a considerable number of cells possesses the stainability for PV-LI only transiently, i.e., in the marmoset, these cells have a specific demand for parvalbumin during this phase of their development. © 1994 Wiley-Liss, Inc. 相似文献
42.
Ezequiel H Cassinelli Corey Wallach Brett Hanscom Molly Vogt James D Kang 《The spine journal》2006,6(4):428-434
BACKGROUND CONTEXT: Posterior lumbar interbody fusion (PLIF) is a popular method of arthrodesis for surgical treatment of instabilities and degenerative conditions of the spine. With the introduction of threaded titanium cage devices, surgeons began performing PLIF procedures using these cages as stand-alone devices. Complications have been reported, however, including pseudarthrosis with persistent pain. Outcomes after revision surgical treatment for these patients with failed PLIF are not known. PURPOSE: To prospectively evaluate clinical outcomes of revision fusion surgery in patients who previously underwent posterior lumbar interbody fusion with stand-alone metallic cages resulting in pseudarthrosis. STUDY DESIGN/SETTING: Prospective case series. METHODS: Nineteen patients referred to the senior author were evaluated and diagnosed with pseudoarthrosis having previously undergone a PLIF procedure with stand-alone metallic cages. History, physical exam, and imaging studies were performed preoperatively and postoperatively. All underwent revision posterolateral fusion with iliac crest graft and pedicle screw instrumentation. Patient demographics, SF-36, and Oswestry Disability Index (ODI) data were collected prior to surgery and two years postoperatively. RESULTS: Patients undergoing revision fusion surgery were found to have had extensive facetectomies and pseudarthrosis intraoperatively. Outcomes data was collected on eighteen of nineteen patients (95%). Mean clinical follow up was 3.2 years (range 2.5-3.5 years). Seventeen patients (94%) achieved a solid fusion. Improvement was noted in seven of eight SF-36 sub-categories, but was significant only in two (Physical Function and Role Emotional). There was no significant difference in ODI scores. CONCLUSIONS: Pseudarthrosis should be considered in the differential diagnosis if severe symptoms persist in patients who undergo PLIF with stand-alone metallic cages. Successful revision fusion did not always correlate with improved clinical outcomes in these challenging patients undergoing further surgery. Performing PLIF using stand-alone metallic cages, especially after total resection of the facet joints, is not advocated unless supplemental instrumentation is utilized. 相似文献
43.
Florian Kronenberg 《Journal of renal nutrition》2005,15(2):195-203
Patients with nephrotic syndrome (NS) have one of the most pronounced secondary changes in lipoprotein metabolism known, and the magnitude of the changes correlates with the severity of the disease. These changes are of a quantitative as well as a qualitative nature. All apolipoprotein B (apo B)-containing lipoproteins, such as very-low-density lipoproteins (VLDL), intermediate-density lipoproteins (IDL), low-density lipoproteins (LDL), and lipoprotein(a) [Lp(a)], are elevated in nephrotic syndrome. High-density lipoproteins (HDL) are reported to be unchanged or reduced. In addition to these quantitative changes, the lipoprotein composition is markedly changed, with a higher ratio of cholesterol to triglycerides in the apo B-containing lipoproteins and an increase in the proportion of cholesterol, cholesterol ester, and phospholipids compared with proteins. Also apolipoproteins show major changes, with an increase in apolipoprotein A-I, A-IV, B, C, and E. Particularly the changes in apo C-II, which is an activator of the enzyme lipoprotein lipase (LPL), and apo C-III, an inhibitor of LPL, with an increase of the C-III to C-II ratio, might contribute to the impaired lipoprotein catabolism in NS. The mechanisms for these changes in lipoprotein metabolism are discussed in this review as far as they are known. Furthermore, the tremendous elevations of Lp(a) in nephrotic syndrome and its primary and secondary causes are reviewed. Primary causes became recently apparent by a significantly higher frequency of low-molecular-weight apo(a) phenotypes in patients compared with controls. The secondary causes were shown by an increase of Lp(a) in all apo(a) isoform groups. Because Lp(a) is an LDL-like particle that is usually included in the measured or calculated LDL cholesterol fraction, the influence of the extremely high Lp(a) levels in NS on the measurement of LDL cholesterol is discussed. 相似文献
44.
P R Vogt E P Bauer T Carrel L K von Segesser M Turina 《European journal of cardio-thoracic surgery》1992,6(2):108-110
Pericarditis constrictiva after cardiac surgery is rare and may occasionally lead to congestive heart failure. The case of a 29-year-old patient is described who presented with pericarditis constrictiva after aortic valve replacement with localized tamponade, causing functional tricuspid stenosis. Pericardiectomy as the treatment of choice was curative. 相似文献
45.
Regina F. Gandour-Edwards Paul J. Donald Philip J. Vogt Robert Munn Kyung-Whan Min 《Head & neck》1994,16(4):379-382
Background. Carcinosarcoma or true malignant mixed tumor of the parotid gland is extremely rare, accounting for <1% of all salivary gland malignancies. Methods. A 63-year-old woman presented with a 5-cm right parotid mass which was resected with a radical parotidectomy and infratemporal fossa dissection. Results. The tumor contained two distinctive histologic patterns, that of a poorly differentiated ductal carcinoma and a pleomorphic rhabdomyosarcoma. Additionally, a residual focus of pleomorphic adenoma was present peripherally, Immunohistochemical and electron microscopic studies confirmed the skeletal muscle differentiation. Conclusions. The pattern of combined rhabdomyosarcoma and ductal carcinoma has not been previously reported and adds further evidence to the myoepithelial derivation of these tumors. © 1994 John Wiley & Sons, Inc. 相似文献
46.
Immunological interferences between kidney and pancreas transplants were investigated in a genetically defined rat model of combined kidney and pancreas transplantation. Kidney and whole-pancreas grafts were transplanted microsurgically either as individual grafts or in a combined technique. Whole pancreas grafts were grafted into streptozotocin diabetic recipients (55 mg/kg bodyweight i.v.) three days after induction of diabetes. The exocrine secretion was suppressed by duct ligation. Rejection of the grafts was defined by recurrence of diabetes in pancreas-grafted recipients and renal failure after kidney transplantation. There were marked differences in the efficacy of identical short-term cyclosporine immunosuppression (15 mg/kg intramuscularly for 14 days): DA kidneys survived indefinitely in LEW rats (MST greater than 100 days), while DA pancreas allografts underwent prolonged but not permanent survival (P less than 0.01) either as individual grafts (MST 27.3 +/- 1,9 days) or when transplanted simultaneously together with the kidney (44 +/- 16 days) (P less than 0.01). LEW rats carrying a DA kidney for 100 days also rejected a subsequent donor-specific pancreas transplant within 30 days. The histological alterations in the kidney were more pronounced than after cyclosporine-induced DA kidney long-term survival alone. By contrast to the rejecting subsequently transferred pancreas, a metachronous second DA kidney was permanently accepted (greater than 100 days) without further immunosuppression after removal of the first graft, while unrelated LEW. 1U kidneys were acutely rejected. In summary, the results indicate that there are not only quantitative differences of kidney and pancreas allograft survival but also differences concerning the state of immunological unresponsiveness induced by identical cyclosporine immunosuppression. While CsA induces donor-specific immunological unresponsiveness after kidney transplantation, pancreas transplants are all eventually rejected after some differential prolongation of survival. Further investigations on the effects of different MHC and minor alloantigens may provide more insight into the complex immunological situation of individual and combined kidney and pancreas transplantation. 相似文献
47.
Elisabeth M Weiss Edith Stadelmann Christian G Kohler Colleen M Brensinger Karen A Nolan Herbert Oberacher Walther Parson Florian Pitterl Harald Niederst?tter Georg Kemmler Hartmann Hinterhuber Josef Marksteiner 《Journal of the International Neuropsychological Society》2007,13(5):881-887
The catechol-O-methyltransferase (COMT) Val158Met polymorphism modulates executive functions and working memory and recent neuroimaging studies implicate an association with emotional processing. We examined the relationship between the COMT Val158Met polymorphism and facial emotion recognition and differentiation in 100 healthy individuals. Compared to Met homozygosity, Val homozygosity was associated with better and faster recognition of negative facial expressions such as anger and sad. Our study provides evidence for a possible influence of the COMT polymorphism on emotion recognition abilities in healthy subjects. Additional research is needed to further define the neurocognitive phenotypes associated with COMT polymorphisms. 相似文献
48.
Jürgen Vogt Torsten Schwarz Daniel Gras Johannes Sperzel Philippe Ritter Willem de Voogt Jean-Pierre Cebron Martin Seifert Bruce Tockman Bernd Schubert Eric Johnson Annette Doelger Thierry Pochet Elisabeth Mouton Christian Butter 《Journal of interventional cardiac electrophysiology》2007,19(1):61-68
Introduction Failure to enter the coronary sinus (CS) with a guiding catheter and entering its tributaries remains challenging in left
ventricle (LV) pacing lead implants for cardiac resynchronization therapy (CRT). A dual telescoping catheter system (8F outer/6F
inner) is designed to provide the ability to adjust the catheter curve size, shape and/or reach to the patients’ anatomy avoiding
the need for catheter change.
Methods Five different designs for CS cannulation were randomly tested in 64 patients scheduled for CRT device implant.
Results In 33 consecutive patients three adaptable telescoping guiding catheter systems were tested per patient, the adaptable catheters
had higher overall cannulation success rates (68, 63 and 62%) compared to the fixed shape catheter (46%) and an greater cannulation
success rate when the CS location was not known (70, 53 and 72% vs 33% for the fixed shape). In a second group of 31 CRT patients
the two telescoping catheters had similar high levels of success (71–80%), with or without using the inner catheter.
Conclusions The telescopic system is adaptable to a wide range of anatomical variations in patients and can result in a higher CS cannulation
success rate due to its adjustability in the RA in search for the CS ostium. On top of this the inner catheter allows for
sub-selecting the CS tributaries. 相似文献
49.
50.
Prof. Dr. P.M. Vogt P. Kolokythas A. Niederbichler K. Knobloch K. Reimers C.Y. Choi 《Der Chirurg》2007,78(4):335-342
The success of modern burn therapy is based mainly on special burn intensive care, topical treatment, early eschar excision, and wound closure by immediate skin grafting or skin substitutes. This paper describes the current state of wound care and skin substitutes in burn therapy. 相似文献