全文获取类型
收费全文 | 21315篇 |
免费 | 1250篇 |
国内免费 | 68篇 |
专业分类
耳鼻咽喉 | 401篇 |
儿科学 | 490篇 |
妇产科学 | 460篇 |
基础医学 | 3611篇 |
口腔科学 | 439篇 |
临床医学 | 1973篇 |
内科学 | 3892篇 |
皮肤病学 | 528篇 |
神经病学 | 1970篇 |
特种医学 | 1135篇 |
外国民族医学 | 1篇 |
外科学 | 3194篇 |
综合类 | 147篇 |
一般理论 | 5篇 |
预防医学 | 1017篇 |
眼科学 | 681篇 |
药学 | 1433篇 |
中国医学 | 28篇 |
肿瘤学 | 1228篇 |
出版年
2022年 | 129篇 |
2021年 | 240篇 |
2020年 | 162篇 |
2019年 | 256篇 |
2018年 | 339篇 |
2017年 | 274篇 |
2016年 | 408篇 |
2015年 | 446篇 |
2014年 | 521篇 |
2013年 | 647篇 |
2012年 | 1141篇 |
2011年 | 1105篇 |
2010年 | 670篇 |
2009年 | 687篇 |
2008年 | 982篇 |
2007年 | 1106篇 |
2006年 | 1128篇 |
2005年 | 1158篇 |
2004年 | 1047篇 |
2003年 | 952篇 |
2002年 | 975篇 |
2001年 | 514篇 |
2000年 | 483篇 |
1999年 | 474篇 |
1998年 | 291篇 |
1997年 | 253篇 |
1996年 | 208篇 |
1995年 | 185篇 |
1994年 | 158篇 |
1993年 | 155篇 |
1992年 | 245篇 |
1991年 | 260篇 |
1990年 | 257篇 |
1989年 | 274篇 |
1988年 | 224篇 |
1987年 | 189篇 |
1986年 | 181篇 |
1985年 | 185篇 |
1984年 | 169篇 |
1983年 | 125篇 |
1982年 | 110篇 |
1981年 | 120篇 |
1979年 | 186篇 |
1978年 | 121篇 |
1977年 | 118篇 |
1976年 | 109篇 |
1975年 | 109篇 |
1974年 | 134篇 |
1973年 | 112篇 |
1972年 | 130篇 |
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
11.
J?rg Müller Klaus Seppi Nadia Stefanova Werner Poewe Irene Litvan Gregor K Wenning 《Movement disorders》2002,17(5):1041-1045
The frequency and pathophysiology of freezing of gait (FoG) in atypical parkinsonism is unknown. We analysed the frequency of FoG in postmortem-confirmed atypical parkinsonian disorders (APD) comprising corticobasal degeneration (CBD), dementia with Lewy bodies (DLB), multiple system atrophy (MSA), and progressive supranuclear palsy (PSP). Sixty-six patients with pathologically confirmed APD (CBD, n = 13; DLB, n = 14; MSA, n = 15; PSP, n = 24) formed the basis for a multicenter clinicopathological study. Clinical features at first and last clinical visit were abstracted from patient records on standardized forms following strict instructions. At the first visit (median 36 months after symptom onset), 24% of APD had FoG (CBD, 8%; DLB, 21%; PSP, 25%; MSA, 40%). Logistic regression analysis showed a significant association of FoG and urinary incontinence (P = 0.04) at first visit. At last visit, 47% of APD had FoG (CBD, 25%; PSP, 53%; DLB, 54%; MSA, 54%). Clinicopathological correlation based on routine postmortem examination failed to identify a consistent neuropathological substrate of FoG. This study demonstrates that (1) FoG is common in APD, and (2) urinary incontinence is significantly associated with FoG in these disorders. Whether FoG and urinary incontinence share similar neuropathological substrates remains to be determined by future studies. 相似文献
12.
13.
Results of Transplanting Developing Third Molars as Part of Orthodontic Space Management 总被引:2,自引:0,他引:2
Oskar Bauss Reza Sadat-Khonsari Werner Engelke Bärbel Kahl-Nieke 《Journal of orofacial orthopedics》2002,63(6):483-492
PATIENTS AND METHOD: The aim of the present study was to contribute to a more accurate indication and better integration of developing third molar transplantation into orthodontic space management, using the results gleaned from the authors' own pool of patients. For this purpose, a clinical and radiographic examination of 61 transplanted developing molars in 57 patients was carried out after an average of 3.3 years. RESULTS: The overall success rate was 85%. Failure was due in 10% of cases to impaired periodontal healing (inflammatory root resorption, ankylosis, or increased pocket probing depths) and in 5% of cases to insufficient or arrested postoperative root development accompanied by increased transplant mobility. The incidence of postoperative cessation of further root development was significantly higher (p = 0.011) in transplants at early developmental stages, which also had a negative impact on the final root length, the crown-root ratio and the mobility values of these transplants. CONCLUSIONS: The transplantation of developing third molars should be given stronger consideration in treatment plans for orthodontic space management although it represents a real alternative to orthodontic space closure only in exceptional cases. However, unlike implantological or prosthodontic treatment, it offers an opportunity to replace a missing or non-retainable tooth with a patient's own vital and fully functional tooth, provided the appropriate transplant is selected. 相似文献
14.
15.
This study measured the pressures under the three most commonly used digital tourniquets--the Penrose drain, the rolled rubber glove, and the rubber band. A miniature pressure transducer and a digital strain indicator were used to measure pressures generated by the various tourniquets. The rolled rubber glove technique was highly consistent, irrespective of the clinical experience of the subject, and uniformly generated pressures of less than 500 mm Hg. Pressures generated by Penrose drains and rubber bands were highly variable and were significantly greater than 500 mm Hg. The so-called calibrated Penrose drain generated the highest pressures in the study. The relationship between tourniquet pressures and neurovascular injury in the human digit is not clearly defined. 相似文献
16.
Saponins from Thinouia coriacea] 总被引:2,自引:0,他引:2
The investigation of the stems of Thinouia coriacea Britton (Sapindaceae), an ichthyotoxic plant from South Brazil, afforded eight glycosides of oleanolic acid. Structures were assigned based on data from partial hydrolysis. 13C-NMR and mass spectral procedures as 3-O-alpha-L-arabinopyranoside (1), 3-O-alpha-L-rhamnopyranosyl-(1----2)-alpha-L-arabinopyranoside+ ++ (2), 3-O-beta-D-glucopyranosyl-(1----4)-alpha-L-arabinopyranoside (3), 3-O-beta-D-glucopyranosyl-(1----3)-alpha-L-rhamnopyranosyl-(1----2 )-alpha-L-arabinopyranoside (4), 3-O-alpha-L-rhamnopyranosyl-(1----2)[beta-D-glucopyranosyl-(1----4 )]-alpha-L-arabinopyranoside (5), 3-O-beta-D-xylopyranosyl-(1----3)-alpha-L-rhamnopyranosyl-(1----2) [beta-D-glucopyranosyl-(1----4)[alpha-L-arabinopyranoside (6), 3-O-beta-D-glucopyranosyl-(1----3)-alpha-L-rhamnopyranosyl-(1----2 )[beta-D-glucopyranosyl-(1----4)]-alpha-L-arabinopyranoside (8). Saponin 7 showed the same sugars as 8, but the attachment between the sugars could not be elucidated. The same saponins were present in the roots, but not in the leaves. 相似文献
17.
Bacterial ghosts (BGs) are empty bacterial envelopes of Gram-negative bacteria produced by controlled expression of cloned gene E, forming a lysis tunnel structure within the envelope of the living bacteria. BGs are devoid of cytoplasmic content and possess all bacterial bio-adhesive surface properties in their original state while not posing any infectious threat. BGs are ideally suited as an advanced drug delivery system (ADDS) for toxic substances in tumor therapy. The inner space of BGs can be loaded with either single components or combinations of peptides, drugs or DNA which provides an opportunity to design new types of (polyvalent) drug delivery vehicles. Uptake of BGs loaded with Doxorubicin (Dox) by CaCo2 cells led to effective Dox release from endo-lysosomal compartments and accumulation in the nucleus. Viability and proliferative capacity of the cells were significantly decreased (2–3 orders of magnitude) after internalization of Dox loaded BGs as compared to cells incubated with free Dox. The same effect was observed with leukemia cells. Melanoma cells also revealed a high capability to internalize BGs. These results indicate that BGs are able to target a range of types of cancer. BGs have also been investigated as DNA delivery vectors. Studies show DNA loaded BGs are efficiently phagocytosed and internalized by both professional APCs and tumor cells with up to 82% of cells expressing the plasmid-encoded reporter gene. Our studies with BGs as an ADDS system contribute (i) to optimize drug delivery for the treatment of cancer; (ii) define specific conditions for selection and preparation of BG formulations; (iii) and provide a background for the clinical application of BGs in cancer therapy. 相似文献
18.
Dr. W. Werner 《Virchows Archiv : an international journal of pathology》1886,106(2):354-377
Ohne ZusammenfassungHierzu Taf. IV. 相似文献
19.
Robert Werner 《Langenbeck's archives of surgery / Deutsche Gesellschaft fur Chirurgie》1915,133(4):354-365
Zusammenfassung Bei der systematischen biologischen Prüfung der verschiedenen Bestandteile bestimmter ?le mineralischen Ursprungs hat sich
herausgestellt, da? deren Kraft, das Wachstum des Bindegewebes anzuregen, allerwahrscheinlichst in dem Gehalte an begrenzten
Mengen unges?ttigter, insbesondere partiell hydrierter Kohlenwasserstoffe zu suchen ist. Auch scheint diese Bindegewebsenergie
durch Spuren h?hermolekularer basischer Stoffe in organischer Bindung und einen ebenfalls begrenzten Gehalt an bestimmten
hydroxylhaltigen K?rpern etwas unterstützt zu werden. Die ?le, bei denen Bindegewebsenergie tierexperimentell festgestellt
werden konnte, enthielten aber zugleich auch Stoffe, die durch übergro?e Reizung zu sch?digen vermochten und daher vor einer
therapeutischen Verwendung ihres ursprünglichen Tr?gers entfernt werden mu?ten. Ein unter Verwertung dieser Erfahrungen hergestelltes
Pr?parat mit durchschnittlich brauchbarstem Gehalte an Bindegewebsenergie ist das “Granulierende Wund?l-Knoll”. Die dauernde
Gleichwertigkeit des Knollschen Wund?les sowie sein stetes Freisein von Nebenwirkungen wird durch biologische Kontrolle einer
jeden Herstellung gew?hrleistet bleiben. 相似文献
20.