全文获取类型
收费全文 | 3969篇 |
免费 | 179篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 45篇 |
儿科学 | 145篇 |
妇产科学 | 90篇 |
基础医学 | 633篇 |
口腔科学 | 190篇 |
临床医学 | 361篇 |
内科学 | 549篇 |
皮肤病学 | 243篇 |
神经病学 | 346篇 |
特种医学 | 207篇 |
外国民族医学 | 1篇 |
外科学 | 566篇 |
综合类 | 11篇 |
预防医学 | 208篇 |
眼科学 | 58篇 |
药学 | 383篇 |
中国医学 | 1篇 |
肿瘤学 | 118篇 |
出版年
2021年 | 48篇 |
2020年 | 41篇 |
2019年 | 43篇 |
2018年 | 39篇 |
2017年 | 27篇 |
2016年 | 59篇 |
2015年 | 74篇 |
2014年 | 63篇 |
2013年 | 129篇 |
2012年 | 182篇 |
2011年 | 162篇 |
2010年 | 114篇 |
2009年 | 87篇 |
2008年 | 168篇 |
2007年 | 143篇 |
2006年 | 185篇 |
2005年 | 166篇 |
2004年 | 139篇 |
2003年 | 143篇 |
2002年 | 150篇 |
2001年 | 158篇 |
2000年 | 141篇 |
1999年 | 111篇 |
1998年 | 56篇 |
1997年 | 44篇 |
1996年 | 41篇 |
1995年 | 30篇 |
1994年 | 46篇 |
1993年 | 33篇 |
1992年 | 69篇 |
1991年 | 66篇 |
1990年 | 70篇 |
1989年 | 60篇 |
1988年 | 42篇 |
1987年 | 35篇 |
1986年 | 46篇 |
1985年 | 47篇 |
1984年 | 29篇 |
1979年 | 40篇 |
1978年 | 30篇 |
1977年 | 22篇 |
1975年 | 30篇 |
1974年 | 35篇 |
1973年 | 25篇 |
1972年 | 27篇 |
1971年 | 23篇 |
1970年 | 26篇 |
1969年 | 25篇 |
1968年 | 22篇 |
1924年 | 22篇 |
排序方式: 共有4155条查询结果,搜索用时 15 毫秒
1.
D. Lothschütz M. Jennewein S. Pahl H.F. Lausberg A. Eichler W. Mutschler R.G. Hanselmann M. Oberringer 《Inflammation research》2002,51(8):416-422
OBJECTIVE AND DESIGN: Inflammatory and tumorous bronchi were screened in order to obtain new tumor relevant cytogenetic parameters. MATERIAL OR SUBJECTS: Bronchial cells of 32 patients were cultivated by standard cell culture procedures. METHODS: Tetraploidy and aneuploidy was determined by enumeration of chromosome 7 and 8 versus the number of centrosomes. The resulting data were correlated with histopathological data. RESULTS: Tetra- and aneuploidy of epithelial cells were detectable in 76% of tumor cell cultures, 75% of high grade inflammatory tissues and 40% of non- and low grade-inflammatory tissues. Additionally, we observed centrosome hyper-amplification and multipolar mitoses not only in the tumor but also in the early stages of inflammation. CONCLUSION: Inflammatory bronchi already show tumor-specific features and may consequently represent the preliminary genetic stage of cancer development in bronchi. 相似文献
2.
P Schuff-Werner E Schütz W C Seyde T Eisenhauer G Janning V W Armstrong D Seidel 《European journal of clinical investigation》1989,19(1):30-37
Heparin-induced Extracorporeal LDL-Precipitation (HELP) is an effective procedure for the elimination of both plasma LDL and fibrinogen. In 10 adult patients with severe type II hyperlipoproteinemia, a single HELP treatment of 3 1 plasma led to an acute decrease in the average plasma viscosity (PV) from 1.30 to 1.1 mPas. At the same time, an even more marked decrease in the mean erythrocyte aggregation rate from a pathological value of 7.9% to a value of 3.7% (normal range less than 5%) was observed. Long-term studies on five patients demonstrated a lasting improvement in these two haemorheological variables. The acute rheological changes were also accompanied by an improvement in polarographically determined muscle oxygen tension. Mean oxygen tension values measured in both the m.biceps brachii and the m.tibialis anterior in five patients before and after a single HELP treatment increased from 30 +/- 4 to 37 +/- 7 mmHg and from 27 +/- 2 to 31 +/- 3 mmHg respectively. These results may provide an explanation for the rapid improvement in patients' clinical symptoms such as angina pectoris and in stress electrocardiogram which have been observed during HELP therapy. 相似文献
3.
AIM: To report the treatment of a recurrent adenoid-cystic carcinoma of the lacrimal gland required orbital exenteration with an en bloc resection of the lateral orbital rim and wall and an anterior portion of the temporal muscle. Reconstruction was planned with both the objectives of a shortened healing time for faster epithetic reconstruction and no visible scars. METHOD: After a cranially extended temporal approach, the dissection of the superficial galea layer was connected with the subcutaneous dissection of the upper and lower eyelid after subciliary incisions. RESULTS: Ample exposure of the temporal, frontal and orbital region was obtained, facilitating the orbital exenteration with en bloc resection of the lateral orbital rim and wall and the anterior portion of the temporal muscle. The epithelialization of the eye socket covered with the galea fascia flap was accelerated, providing faster epithetic reconstruction, without visible scars. CONCLUSIONS: Healing time is accelerated, providing faster epithetic rehabilitation without visible scars, which is important in the postoperative rehabilitation ladder after eye exenteration for both patient and surgeon. Further more ablative surgery within this region gets safer and easier due to the ample exposure of this innovative surgical technique. Further evaluation of the effectiveness and safety of this new approach is advisable. 相似文献
4.
Axel Olsen T. Antoine Frommolt Theo Pütz Rudolf Koch Hans Heidler Kurt Walther Schultze H. A. Schmitz Elisabeth Koch Möhlmann Diethelm W. Janisch-Raschkowitsch Hansen Ostertag H. Dietel 《International journal of legal medicine》1943,37(3-4):197-206
Ohne Zusammenfassung 相似文献
5.
A. Lange P. Funch-Jensen P. Thommesen & P. O. Schiøtz 《Neurogastroenterology and motility》1997,9(2):55-62
Epigastric impedance was used to measure the gastric emptying patterns of a liquid non-caloric meal (5 mL water kg−1 ) in 30 healthy newborn infants. Twenty-six mature infants were examined in the first eight days of life, and four preterm infants were examined within 6 weeks after birth. The recordings consisted of two components: the emptying signal (the DC component), and a phasic 3 cycles per minutes (CPM) signal (the AC component). In some of the infants the phasic 3 CPM signal was also seen during the fasting state.
For mature infants the median half emptying time (T50 ) was 6.9 min. For a second meal given within one hour after the first meal the half emptying time was 5.5 min ( P < 0.01). In preterm infants the emptying times were not significantly different from mature infants.
Day-to-day variation was low with a coefficient of variation of 17% in nine infants.
A periodic change of the impedance signal, the phasic 3 CPM signal, was observed after a meal in 24 of the infants. The median frequency was 3.0 CPM in 20 mature and 2.9 CPM in four preterm infants. In nine infants a phasic 3 CPM signal was also observed during the fasting state, with a median frequency of 2.9 CPM.
Measurement of gastric emptying pattern with epigastric impedance is a simple investigation for the evaluation of gastric emptying time and phasic activity in mature and preterm infants. However, the method is sensitive to spontaneous movements of the children, resulting in non-valid measurements in around one fourth of the infants. 相似文献
For mature infants the median half emptying time (T
Day-to-day variation was low with a coefficient of variation of 17% in nine infants.
A periodic change of the impedance signal, the phasic 3 CPM signal, was observed after a meal in 24 of the infants. The median frequency was 3.0 CPM in 20 mature and 2.9 CPM in four preterm infants. In nine infants a phasic 3 CPM signal was also observed during the fasting state, with a median frequency of 2.9 CPM.
Measurement of gastric emptying pattern with epigastric impedance is a simple investigation for the evaluation of gastric emptying time and phasic activity in mature and preterm infants. However, the method is sensitive to spontaneous movements of the children, resulting in non-valid measurements in around one fourth of the infants. 相似文献
6.
P2-, but not P1-purinoceptors mediate formation of 1, 4, 5-inositol trisphosphate and its metabolites via a pertussis toxin-insensitive pathway in the rat renal cortex. 总被引:3,自引:3,他引:0 下载免费PDF全文
1. The adenosine receptor (P1-purinoceptor) agonists N6-cyclopentyladenosine and N-5'-ethyl-carboxamidoadenosine at concentrations up to 10 mumols 1(-1) affected neither basal, nor noradrenaline- and angiotensin II-stimulated formation of inositol-1-phosphate, inositol-1,4-bisphosphate, and inositol-1,4,5-trisphosphate in slices of rat renal cortex. 2. In contrast, adenine nucleotides (P2-purinoceptor agonists) markedly stimulated inositol phosphate formation. The observed rank order of potency adenosine-5'-O-(2-thiodiphosphate) (EC50 39 mumols 1(-1] greater than adenosine-5'-O-(3-thiotriphosphate) (587) greater than or equal to 5'-adenylylimidodiphosphate (App(NH)p, 899) greater than adenylyl-(beta, gamma-methylene)-diphosphate (4,181) was consistent with the interaction of the compounds with the P2Y-subtype of P2-purinoceptors. AMP and the ADP analogue (alpha, beta-methylene)-adenosine-5'-diphosphate were ineffective. ATP and ADP (less than or equal to 10 mmol 1(-1] did not produce a consistent increase, owing to their hydrolytic degradation in the incubation medium. 3. Whereas the inositol phosphate response to App(NH)p was linear only up to 5 min incubation, the time-dependent stimulation of noradrenaline declined at a slower rate. Following pre-exposure of the renal cortical slices to App(NH)p, renewed addition of App(NH)p caused no further enhancement in the accumulation of inositol phosphates, whilst noradrenaline was still capable of eliciting a response. This suggests that the apparent loss of responsiveness to App(NH)p is not due to substrate depletion or enzymatic inactivation, but most likely attributable to homologous desensitization of the purinoceptor.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
7.
BACKGROUND--The neutrophil is a potent contributor to pulmonary destruction in cystic fibrosis. Since eosinophils also possess destructive potential the involvement of eosinophils in cystic fibrosis has been investigated. METHODS--Eosinophil numbers and levels of eosinophil cationic protein (ECP), a marker of eosinophil activation, were determined in the serum of 42 patients with cystic fibrosis and in the sputum of 10 of them. To determine neutrophil activation levels of myeloperoxidase (MPO) were also measured. RESULTS--In cystic fibrosis increased serum levels of ECP were detected compared with healthy non-atopic subjects. Serum ECP levels were not related to the peripheral blood eosinophil count. A strong correlation with ECP concentrations in sputum indicated that the level of ECP in serum was representative of its pulmonary level. Levels of MPO were also increased in cystic fibrosis. A strong correlation was found between MPO and pulmonary function. In addition, ECP was related to arterial oxygen and carbon dioxide tensions. Antibiotic treatment reduced neutrophil activation without effect on ECP levels. CONCLUSIONS--Until now Pseudomonas aeruginosa and neutrophils were held to be primarily responsible for progressive tissue damage in cystic fibrosis. The results of this study suggest that eosinophils might also participate in such pulmonary destruction. 相似文献
8.
Expression profiling identifies the CRH/CRH-R1 system as a modulator of neurovascular gene activity.
Jan M Deussing Claudia Kühne Benno Pütz Markus Panhuysen Johannes Breu Mary P Stenzel-Poore Florian Holsboer Wolfgang Wurst 《Journal of cerebral blood flow and metabolism》2007,27(8):1476-1495
Corticotropin-releasing hormone receptor type 1 (CRH-R1)-deficient mice display reduced anxiety-like behavior, a chronic corticosterone deficit, and an impaired neuroendocrine stress response caused by disruption of the hypothalamic-pituitary-adrenocortical (HPA) axis. The molecular substrates and pathways of CRH/CRH-R1-dependent signaling mechanisms underlying the behavioral phenotype as well as the consequences of lifelong glucocorticoid deficit remain largely obscure. To dissect involved neuronal circuitries, we performed comparative expression profiling of brains of CRH-R1 mutant and wild-type mice using our custom made MPIP (Max Planck Institute of Psychiatry) 17k cDNA microarray. Microarray analysis yielded 107 genes showing altered expression levels when comparing CRH-R1 knockout mice with wild-type littermates. A significant proportion of differentially expressed genes was related to control of HPA and hypothalamic-pituitary-thyroid (HPT) axes reflecting not only the disturbance of the HPA axis in CRH-R1 mutant mice but also the interplay of both neuroendocrine systems. The spatial analysis of regulated genes revealed a prevalence for genes expressed in the cerebral microvasculature. This phenotype was confirmed by the successful cross-validation of regulated genes in CRH overexpressing mice. Analysis of the cerebral vasculature of CRH-R1 mutant and CRH overexpressing mice revealed alterations of functional rather than structural properties. A direct role of the CRH/CRH-R1 system was supported by demonstrating Crhr1 expression in the adult murine cerebral vasculature. In conclusion, these data suggest a novel, previously unknown role of the CRH/CRH-R1 system in modulating neurovascular gene expression and function. 相似文献
9.
J M G?tz A J Nielander P J Brouwers C H ten Napel 《Nederlands tijdschrift voor geneeskunde》1992,136(33):1611-1613
Transfusion-associated symptomatic HIV infection in four patients led to death in two patients and to development of serious neurological sequelae in a third patient who also transmitted HIV infection to his spouse. The tardy diagnosis of HIV-associated disease in all cases can be ascribed to ignoring the earlier blood transfusion as a possible cause of HIV infection. This was due partly to advanced age of the patients and partly to lack of familiarity of the attending physicians with HIV-associated problems. This resulted in a substantial doctor's delay. 相似文献
10.
P Reitzig H J Gütz E Apostoloff F Irro G Pilgrim I Herbrandt 《Deutsche Zeitschrift für Verdauungs- und Stoffwechselkrankheiten》1987,47(3):101-104
The authors tried to clarify relations between autoimmune gastritis and isolated atrophic corpus gastritis by bioptic corporal and antral examinations from 150 probands as well as examinations of gastrin in serum and parietal cell antibody tests. Only 30% of all patients examined with isolated atrophic gastritis of the corpus part revealed criteria of an autoimmune gastritis. Therefore investigations of antibodies against parietal cells are necessary to mark off both clinical pictures. This differentiation seems to be necessary regarding the high risk of gastric cancer following an autoimmune gastritis. 相似文献