全文获取类型
收费全文 | 2032篇 |
免费 | 114篇 |
国内免费 | 5篇 |
学科分类
医药卫生 | 2151篇 |
出版年
2021年 | 13篇 |
2020年 | 21篇 |
2019年 | 19篇 |
2018年 | 31篇 |
2017年 | 17篇 |
2016年 | 40篇 |
2015年 | 42篇 |
2014年 | 61篇 |
2013年 | 79篇 |
2012年 | 92篇 |
2011年 | 112篇 |
2010年 | 85篇 |
2009年 | 75篇 |
2008年 | 89篇 |
2007年 | 108篇 |
2006年 | 98篇 |
2005年 | 107篇 |
2004年 | 102篇 |
2003年 | 78篇 |
2002年 | 95篇 |
2001年 | 39篇 |
2000年 | 50篇 |
1999年 | 52篇 |
1998年 | 28篇 |
1997年 | 21篇 |
1996年 | 14篇 |
1995年 | 20篇 |
1994年 | 17篇 |
1993年 | 23篇 |
1992年 | 28篇 |
1991年 | 28篇 |
1990年 | 28篇 |
1989年 | 21篇 |
1988年 | 27篇 |
1987年 | 23篇 |
1986年 | 17篇 |
1985年 | 24篇 |
1984年 | 11篇 |
1983年 | 23篇 |
1981年 | 14篇 |
1979年 | 14篇 |
1978年 | 16篇 |
1976年 | 9篇 |
1974年 | 13篇 |
1973年 | 18篇 |
1972年 | 11篇 |
1971年 | 10篇 |
1970年 | 13篇 |
1969年 | 12篇 |
1967年 | 9篇 |
排序方式: 共有2151条查询结果,搜索用时 15 毫秒
1.
Hendrik Seeliger Alois Fürst Carl Zülke Karl-Walter Jauch 《Langenbeck's archives of surgery / Deutsche Gesellschaft fur Chirurgie》2002,387(7-8):286-293
BACKGROUND: Biliary tract lesions pose a dreaded complication of laparoscopic cholecystectomy. In a retrospective study we analyzed the clinical presentation, diagnostic and therapeutic management and outcome of 28 patients presenting with iatrogenic bile duct injuries. PATIENTS AND METHODS: Between 1994 and 2001 we treated 28 patients with bile duct lesions following laparoscopic cholecystectomy at our center. Operation notes and charts of all patients were reviewed systematically. A follow-up examination of each patient was performed after a median of 12 months (range 1-90). RESULTS: Twenty-two patients presented with major circumferential bile duct defect lesions. Less severe injuries (n=6) were two minor bile leaks, one bile duct stricture and three tangential lesions. Twenty-six patients were referred to our institution within 16 days (range 0-226 days). Six patients were treated by nonsurgical procedures: endoscopic stenting in four and percutaneous intervention in two. In one of the remaining patients a cystic duct leak was closed via laparotomy, and in 21 a hepaticojejunostomy was performed. Reconstruction of a hepaticojenunostomy was performed in two of these patients. Patients were dismissed from the hospital after a median of 13 days (range 4-156). Four patients presenting with generalized biliary peritonitis required prolonged intensive care. One or more episodes of cholangitis were seen in five patients during follow-up examinations. CONCLUSIONS: Major iatrogenic bile duct injuries are associated with high morbidity and prolonged hospitalization. Interdisciplinary cooperation and early referral to an experienced center is crucial in the management of patients suffering from this affliction. Cholangitis is a marked problem in the follow-up. 相似文献
2.
P B Schneider U Denk M Breitenbach K Richter P Schmid-Grendelmeier S Nobbe M Himly A Mari C Ebner B Simon-Nobbe 《Clinical and experimental allergy》2006,36(12):1513-1524
BACKGROUND: Alternaria alternata is one of the most important allergenic fungi worldwide. Mannitol dehydrogenase (MtDH) has previously been shown to be a major allergen of Cladosporium herbarum and cross-reactivity has been demonstrated for several fungal allergens. OBJECTIVE: The present study's objective was to clone the MtDH from an A. alternata cDNA library, express and purify the recombinant non-fusion protein and test its IgE-binding properties. Methods A cDNA library prepared from A. alternata hyphae and spores was screened for mannitol dehydrogenase by DNA hybridization with the radioactively labelled C. herbarum homologue as a probe. The resulting clone was sequenced and heterologously expressed in Escherichia coli as a recombinant non-fusion protein, which was purified to homogeneity and analysed for its IgE-binding capacity. RESULTS: The coding sequence of the full-length cDNA clone comprises 798 bp encoding a protein with a molecular mass of 28.6 kDa and a predicted pI of 5.88. Protein sequence analysis revealed an identity of 75% and a homology of 86% between the MtDHs of A. alternata and C. herbarum. The functional mannitol dehydrogenase was expressed in the E. coli strain BL21(DE3) transformed with the vector pMW172 and purified to homogeneity. The enzyme catalyses the NADPH-dependent conversion of d-fructose to d-mannitol. In IgE-ELISA and immunoblots, MtDH is recognized by 41% of A. alternata-allergic patients. In vivo immunoreactivity of the recombinant MtDH was verified by skin prick testing. Finally, inhibition-ELISA experiments confirmed cross-reactivity between the MtDHs of A. alternata and C. herbarum. CONCLUSION: Mannitol dehydrogenase (Alt a 8) represents an important new allergen of the ascomycete A. alternata that might be suitable for improving diagnostic and therapeutic procedures. 相似文献
3.
4.
B. Jahn-Schmid C. Harwanegg† R. Hiller† B. Bohle C. Ebner O. Scheiner M. W. Mueller† 《Clinical and experimental allergy》2003,33(10):1443-1449
BACKGROUND: The availability of recombinant allergens and recent advances in biochip technology led to the development of a novel test system for the detection of allergen-specific IgE. OBJECTIVE: To test the performance of this allergen microarray in a serological analytical study. METHODS: Standard allergens contained in grass pollen (Phl p 1, Phl p 2, Phl p 5 and Phl p 6) and tree pollen (Bet v 1 and Bet v 2) were used as a model system. The detection of allergen-specific serum IgE using microarrays was compared with standard test systems: CAP/RAST and an in-house ELISA. In order to test the analytical sensitivity of the assays, geometric dilutions of a serum pool containing high levels of pollen-specific IgE from allergic individuals were tested in each system. To assess the analytical specificity, the sera of 51 patients with presumptive allergic symptoms were collected before diagnosis. Thereafter, the results for grass/tree-pollen-specific IgE were compared. RESULTS: The microarray has a good dynamic range similar to the CAP/RAST system. Microarray and ELISA showed comparable analytical sensitivity exceeding the CAP/RAST system. With respect to the analytical specificity, no significant cross-reactivity of the allergens was observed. For two of the allergens tested, weak positive signals were detected in the microarray test system, whereas they were not detectable by CAP/RAST. CONCLUSION: A good correlation of presently used methods to detect serum IgE and the novel microarray test system was observed. As a next step, a careful validation of this method for a multitude of allergens and a thorough clinical evaluation has to be provided. Microarray testing of allergen-specific IgE can be presumed to be the method of choice for a prospective component-resolved diagnosis of Type I allergy, and the basis for the design and monitoring of a patient-tailored specific immunotherapy in the future. 相似文献
5.
6.
Factors influencing the onset of ouabain inhibition of Na,K-ATPase from guinea-pig myocardium. 总被引:1,自引:0,他引:1 下载免费PDF全文
F. Ebner 《British journal of pharmacology》1990,101(2):337-343
1. The onset of ouabain inhibition was quantified by analysis with an integrated rate equation from experiments in which the activity of Na,K-ATPase from guinea-pig myocardium had been altered with adenosine 5'-triphosphate (ATP, 0.3-9 mmoll-1) in the absence and presence of a detergent. 2. Under control conditions with increasing ouabain (0.1-100 mumoll-1) and ATP (0.3-1 mmoll-1) concentrations, inhibition developed faster. The acceleration by ouabain became less effective at saturating concentrations leading to a non-linear relationship between pseudo-first-order rate constants of inhibition and ouabain concentration. With a rise of ATP to 3 and 9 mmoll-1, i.e., near total Mg concentration (5 mmoll-1), inhibition was retarded presumably because the free concentrations of Mg and uncomplexed ATP changed. Varying the ATP concentration had little effect on ouabain potency at steady state; Hill coefficients were less than 1. 3. The detergent alamethicin (23 micrograms ml-1) neither interfered with Na,K-ATPase activity nor with inhibition at steady state but accelerated its onset. This supports a role for a lipid barrier in the development of inhibition. 4. While the reaction of low concentrations of ouabain with the receptors seemed to govern inhibition rate, with an increase in steroid concentration in the presence of alamethicin, ATP-dependent enzyme activity interfered with the onset of inhibition. The transition of the enzyme between ouabain-sensitive and ATP-hydrolytic conformations consequently causes the non-linear concentration-dependence of pseudo-first-order rate constants. As the Hill coefficient was less than 1, a reaction of ouabain with two receptors also could have contributed to the special concentration-dependence of inhibition rates. 相似文献
7.
F. Schmidt R. Stollberger M. Pedevilla J. Simbrunner K. Hartwagner F. Ebner 《European Surgery》1997,29(3):115-117
Zusammenfassung
Grundlagen: Der Zweck war es, die Anzahl der im Mammogramm entdeckten duktalen Carcinoma in situ (DCIS) und multizentrische Karzinome
aufzudecken. Die verschiedenen Methoden der Biopsie werden diskutiert.
Methodik: Rastermammographie (Fokus 0,3 mm) und hochaufl?sende Sonographie (7,5 bis 10 MHz) wurden bei Brustkrebspatientinnen eingesetzt.
Ergebnisse: Der Zeitraum der aufgelisteten Patientinnen erstreckt sich über 20 Jahre. Die Zahl der DCIS hat in den letzten Jahren zugenommen
und betr?gt nun 18%. Die Mammographie ist hoch sensitiv für Entdeckung von Mikrokalzifikationen. Die Spezifit?t ist gering.
Schlu?folgerungen: Die Anzahl der entdeckten DCIS ist in den letzten Jahren besonders angestiegen und wird auch noch weiter bei Verbesserung
der mammographischen Techniken ansteigen.
Diese Studie wurde vom Ludwig-Boltzmann-Institut für radiologisch-physikalische Tumordiagnostik unterstützt. 相似文献
8.
Martina Plísková Jan Vondrácek Borivoj Vojtesek Alois Kozubík Miroslav Machala 《Toxicological sciences》2005,83(2):246-256
Polycyclic aromatic hydrocarbons (PAHs), such as benzo[a]pyrene (BaP), are carcinogens suggested to be involved in development of human cancer. Several recent studies have reported that PAHs can activate estrogen receptors (ER), either directly or indirectly by producing estrogenic metabolites. We hypothesized that the activation of ER by PAHs or their metabolites could induce cell proliferation in estrogen-sensitive cells. In the present study, we found that two PAHs, benz[a]anthracene (BaA) and BaP, can stimulate proliferation of human breast carcinoma MCF-7 cells at concentrations 100 nM and higher. This effect was ER-dependent, because it was blocked by the pure antiestrogen ICI 182,780. Although both PAHs partially inhibited S-phase entry and DNA synthesis induced by 17beta-estradiol, they stimulated S-phase entry when applied to MCF-7 cells synchronized by serum deprivation. This was in contrast with model antiestrogenic aryl hydrocarbon receptor ligand, 2,3,7,8-tetrachlorodibenzo-p-dioxin, which fully suppressed S-phase entry. BaP, which is a strong mutagen, was found to induce p53 tumor suppressor expression, a partial S-phase arrest and at higher concentrations also cell death. Pifithrin-alpha, a synthetic inhibitor of p53 activity, abolished both S-phase arrest and apoptosis induced by genotoxic PAHs, and it potentiated the proliferative effect of BaP. Thus, both genotoxic and nongenotoxic events seem to interact in the effects of BaP on cell proliferation. Taken together, our data indicate that both BaA and BaP can stimulate cell proliferation through activation of ER. The proliferative effects of these carcinogenic compounds might contribute to tumor promotion in estrogen-sensitive tissues. 相似文献
9.
Pachycarpine (4), the optical antipode of the lupine alkaloid (-)-sparteine (1), has been prepared from (-)-lupanine; its metabolism was studied in rats. After isolation and chromatographic purification, streochemically homogeneous (+)-(4S)-hydroxysparteine (7) was identified as the major urinary metabolite by use of mass spectrometry and high-field NMR-spectroscopy. 相似文献
10.
Recent evidence suggests that several bioactive polypeptides, among them substance P, neurokinin A, and calcitonin gene-related peptide, are contained in tracheobronchial C-fibers. These peptides can be released from the lung by irritant chemicals or local inflammatory mediators like histamine or bradykinin. Substance P mimicks the increase in vascular permeability caused by vagal nerve stimulation and neurokinin A mimicks noncholinergic bronchoconstriction by vagal nerve stimulation. Calcitonin gene-related peptide displays vasodilator activity. Experiments carried out with sensitized guinea pigs showed a contribution of tracheobronchial C-fibers to the anaphylactic response. Additionally, capsaicin, which in high concentration selectively blocks sensory C-fibers, was found to be effective in treatment of hyperreactive rhinopathy (vasomotor rhinitis). It is concluded that peptide mediators released from tracheobronchial C-fibers may contribute to the pathophysiology of various allergic or inflammatory airway diseases. 相似文献