全文获取类型
收费全文 | 6351篇 |
免费 | 352篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 30篇 |
儿科学 | 130篇 |
妇产科学 | 35篇 |
基础医学 | 840篇 |
口腔科学 | 181篇 |
临床医学 | 529篇 |
内科学 | 1027篇 |
皮肤病学 | 158篇 |
神经病学 | 537篇 |
特种医学 | 266篇 |
外科学 | 858篇 |
综合类 | 21篇 |
预防医学 | 1220篇 |
眼科学 | 145篇 |
药学 | 378篇 |
中国医学 | 4篇 |
肿瘤学 | 352篇 |
出版年
2022年 | 25篇 |
2021年 | 103篇 |
2020年 | 49篇 |
2019年 | 63篇 |
2018年 | 90篇 |
2017年 | 86篇 |
2016年 | 107篇 |
2015年 | 126篇 |
2014年 | 147篇 |
2013年 | 200篇 |
2012年 | 347篇 |
2011年 | 363篇 |
2010年 | 209篇 |
2009年 | 237篇 |
2008年 | 327篇 |
2007年 | 348篇 |
2006年 | 298篇 |
2005年 | 289篇 |
2004年 | 299篇 |
2003年 | 286篇 |
2002年 | 230篇 |
2001年 | 107篇 |
2000年 | 132篇 |
1999年 | 102篇 |
1998年 | 58篇 |
1997年 | 63篇 |
1996年 | 106篇 |
1995年 | 222篇 |
1994年 | 214篇 |
1993年 | 183篇 |
1992年 | 210篇 |
1991年 | 191篇 |
1990年 | 130篇 |
1989年 | 56篇 |
1988年 | 48篇 |
1987年 | 64篇 |
1986年 | 60篇 |
1985年 | 45篇 |
1984年 | 36篇 |
1983年 | 32篇 |
1982年 | 21篇 |
1981年 | 24篇 |
1980年 | 24篇 |
1979年 | 30篇 |
1978年 | 27篇 |
1977年 | 26篇 |
1975年 | 25篇 |
1974年 | 19篇 |
1973年 | 25篇 |
1971年 | 18篇 |
排序方式: 共有6711条查询结果,搜索用时 390 毫秒
41.
M. Brugiatelli B. Jaksic A. Planinc-Peraica R. Kusec S. Ostojic V. Callea P. Lacopino F. Morabito C. Stelitano D. Lutz 《European journal of haematology》1995,55(3):158-163
Abstract: In 1982 the IGCI CLL cooperative group decided to investigate the usefulness of treating, at diagnosis B-cell chronic lymphocytic leukemia (CLL) in early and stable phase of the disease. From January 1982 to December 1986, 148 patients were randomized either to receive immediate treatment with chlorambucil (CLB) or to defer therapy to the time of progression. The early and stable phase of the disease was defined by a total tumor mass (TTM) score < 9, the absence of anemia or thrombocytopenia and a doubling time > 12 months. The main end-point of the study was survival. At the last evaluation in April 1993, after a median follow-up of 75 months, no significant difference was found in overall survival between early vs. deferred treatment patients from every cause of death as well as from death due to CLL-related causes only. The same results were obtained when the patients in more favorable stages, such as Binet stage A and TTM < 4.5, were considered. Interestingly, the incidence of epithelial cancer was similar in the two groups. Early treatment was associated with a significantly better response and a lower progression rate. From this long-term experience, it can be concluded that immediate chemotherapy with CLB is not beneficial for CLL patients in early and stable phase of the disease in terms of survival. 相似文献
42.
J. Lutz H. -G. Schulze U. F. Michael 《Pflügers Archiv : European journal of physiology》1975,359(4):285-295
The degree of O2 saturation and different data of acid-base status are determined from pO2, pH, and pCO2 values bya programmable pocket calculator. Since the operating program should be usable for different species and also in the range of very low O2 saturations, obviously the usual Hill equation for calculating the oxygen dissociation curve of hemoglobin is not applicable; the same is true is some cases for the Adair equation. Thus a 3-fold subdivision of the dissociation curve was undertaken and programmed. Suitable programs for several species could be established despite the limited number of program steps in the new calculator, giving systematic deviations in calculated O2 saturations of less than or equal to +/- 0.9 saturation precent over the full range of dissociation curves. A reverse procedure for calculation of pO2 from saturation is added. In situations where pCO2 or base excess are not known or only estimated, limits of the arising error are stated. In the acid-base program 7 parameters are evaluated partially using empirical formulae derived from nomograms. The programmable pocket calculator offers advantages of small size, economy, and independence of line voltage compared to much more spacious units and a precision equal or superior to nomograms. 相似文献
43.
44.
Neoglycoprotein binding to colorectal tumour cells: Comparison between primary and secondary lesions
Hans -J. Gabius Thomas Grote Sigrun Gabius Ulrich Brinck Lutz F. Tietze 《Virchows Archiv : an international journal of pathology》1991,419(3):217-222
Summary Biotinylated neoglycoproteins are useful to determine the expression of sugar receptors (lectins) histochemically in routinely processed tissue sections. Assessment of the presence of distinct receptor classes with specificity to-galactosides and to- or-N-acetylgalactosamine, selected on the basis of their potential relevance for recognition processes within the metastatic cascade in murine model systems, was performed for a common human tumour type, colorectal cancer. The four different types of neoglycoproteins, derived from covalent attachment of commercially available derivatives of-N-acetylgalactosamine, differed only quantitatively in their capacity to detect specific binding on cultured cells and tissue sections, thus posing no major restriction on the choice of synthetic process for histochemical efficiency of the product. Glycocytological application revealed specific probe binding and a regulation of level of receptor expression for a human colon carcinoma cell line primarily forN-acetylgalactosamine-specific receptors upon retinoic acid-induced differentiation. Monitoring of sections of the 12 cases of primary and secondary colorectal lesions invariably disclosed the presence of the respective receptors, the extent of cell labelling in primary tumours and metastases being similar. Establishment of metastases, even in different target organs, is apparently not followed by a major phenotypic variation in this feature. 相似文献
45.
Effect of Pseudomonas aeruginosa cytotoxin on thymidine incorporation by murine splenocytes.
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
T G Obrig A L Baltch T P Moran S P Mudzinski R P Smith F Lutz 《Infection and immunity》1984,45(3):756-760
The interaction of highly purified Pseudomonas aeruginosa cytotoxin (PAC) with murine splenocytes was examined. Added at culture initiation, PAC (0.1 to 0.5 microgram/ml) inhibited subsequent [3H]deoxythymidine incorporation measured between 42 to 48 h. Incorporation of [3H]deoxythymidine was inhibited 50% in lipopolysaccharide-, phytohemagglutinin-, and concanavalin A-stimulated cultures by 0.20, 0.32, and 0.39 microgram of PAC per ml, respectively. It is concluded that PAC exhibits a narrow inhibitory concentration response range of 0.1 to 0.5 microgram/ml which, secondarily, is affected by the presence of mitogens. Antitoxin added at splenocyte culture initiation, directly after PAC, yielded greater than or equal to 86% protection against PAC inhibition of [3H]deoxythymidine incorporation. Addition of antitoxin to cultures at different times after PAC demonstrated a time-dependent loss of antitoxin protective effect over a 12-h period, indicating that PAC became cell associated and refractory to antitoxin within this time period. PAC preincubated with splenocytes at 4 degrees C for less than or equal to 1 h could not be removed by washing of cells and was fully inhibitory to [3H]deoxythymidine incorporation when these cells were cultured at 37 degrees C. This finding was confirmed by demonstrating that 125I-labeled PAC bound immediately to cells. It is concluded that PAC action on splenocytes is dose- and time-dependent and consists of a two-phase process: (i) a very rapid binding of PAC to the cell surface available to antitoxin, and (ii) a slower toxicity development phase of ca. 12 h, during which PAC becomes refractory to antitoxin. 相似文献
46.
OBJECTIVE: The objective of this study was to analyze the autonomic functions of patients with erythrophobia. METHODS: Forty patients with a diagnosis of erythrophobia (female/male ratio 18/22) without any other organic lesions and 20 healthy volunteers (female/male ratio 10/10) were assessed. Clinical evaluation was performed using a modified version of semistructured interviews. Autonomic testing was performed by means of spectral analysis of heart rate and continuous blood pressure by sparse discrete Fourier transformation at rest and under mental stress. RESULTS: There were no significant difference between the two samples in age, sex distribution, BMI, resting systolic, or diastolic blood pressure, nor was there a difference in autonomic baseline functioning between the 40 patients with erythrophobia and the control subjects. On the other hand, patients with erythrophobia consistently showed higher pulse rates (88 +/- 20 vs. 78 +/- 9 bpm, p <.05), higher total heart rate power values (8.40 +/- 0.63 vs. 8.07 +/- 1.02 p <.05), higher midfrequency spectral values (7.38 +/- 0.66 vs. 7.02 +/- 1.18, p <.01), higher high-frequency spectral values (6.89 +/- 0.86 vs. 6.48 +/- 1.44, p <.05), and lower baroreceptor sensitivity (8.62 +/- 8.16 vs. 11.65 +/- 4.42, p <.005) than the healthy subjects. ANOVA showed a significant group interaction (p <.0001) between the samples. CONCLUSIONS: This study provides evidence for abnormal autonomic functioning in patients with erythrophobia when under mental stress. 相似文献
47.
48.
D G Tinkelman B S Garcha C N Lutz 《The Journal of allergy and clinical immunology》1990,85(4):750-755
With an increased awareness of the importance of bronchial hyperreactivity on the clinical state of asthma, efforts at establishing effective treatment for asthma have been aimed at trying to reduce the level of bronchial hyperreactivity. This study investigated whether or not theophylline at different serum concentrations had any effect on bronchial hyperreactivity, as measured by methacholine challenges. Twelve adult subjects with mild asthma participated. All subjects were atopic and were nonsmokers. Subjects were studied on three separate occasions according to a double-blind, randomized, crossover study design with one of the following medications: two placebo capsules in the morning and evening, a placebo and 250 mg of sustained-release theophylline in the morning and evening, or two 250 mg sustained-release theophylline capsules each morning and evening. Subjects were administered their medication between 5 and 15 days before performing methacholine challenges in the morning at the presumed trough level, and in the afternoon at the presumed peak serum theophylline level. Despite statistically significant differences in the pulmonary function and theophylline levels between the two active dosages (p less than 0.05 for both), there was no difference in methacholine sensitivity at the time of ingestion of the two dosage forms. There was also no correlation between a particular theophylline level and degree of methacholine sensitivity. It was concluded that, although theophylline has significant bronchodilator capability, it has little, if any, effect on bronchial hyperreactivity, as measured by methacholine challenges. Thus, other forms of long-term therapy should be used in reducing bronchial hyperreactivity. 相似文献
49.
Seroprevalence of Ehrlichia canis and of Canine Granulocytic Ehrlichia Infection in Dogs in Switzerland 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Nicola Pusterla Jeannine Berger Pusterla Peter Deplazes Celestine Wolfensberger Werner Müller Angelika Hrauf Claudia Reusch Hans Lutz 《Journal of clinical microbiology》1998,36(12):3460-3462
Serum samples from 996 dogs in Switzerland were examined for antibodies to Ehrlichia canis and to the agent causing canine granulocytic ehrlichiosis (CGE). Ehrlichiosis, borreliosis, and systemic illness not associated with ticks were suspected in 75, 122, and 157 of these dogs, respectively. The remainder of the serum samples were obtained from clinically healthy dogs which resided north (n = 235) or south (n = 407) of the Alps. The serum samples were tested by an indirect immunofluorescence technique for antibodies to the two agents incriminated, E. canis and Ehrlichia phagocytophila, a surrogate marker of the agent of CGE. Twenty-two of 996 (2.2%) serum samples had antibodies to E. canis and were distributed as follows: 20 of 75 (26.7%) samples from dogs suspected of having ehrlichiosis, 1 of 122 (0.8%) from dogs suspected of having borreliosis, and 1 of 407 (0.2%) from healthy dogs which resided south of the Alps. Of the 75 (7.5%) serum samples that had antibodies to E. phagocytophila, significantly more samples were from ill dogs than from healthy dogs. Among the sera from healthy dogs, antibodies to E. phagocytophila were significantly more prevalent in the north. Because seropositive dogs had a history of travel outside Switzerland and because Rhipicephalus sanguineus is found exclusively south of the Alps, it was presumed that, in contrast to the agent of CGE, E. canis is not indigenous to Switzerland. 相似文献
50.
Lois J. Starr Jürgen W. Spranger Vamshi K. Rao Richard Lutz Anji T. Yetman 《American journal of medical genetics. Part A》2019,179(7):1270-1275
PIGQ (OMIM *605754) encodes phosphatidylinositol glycan biosynthesis class Q (PIGQ) and is required for proper functioning of an N‐acetylglucosamine transferase complex in a similar manner to the more established PIGA, PIGC, and PIGH. There are two previous patients reported with homozygous and apparently deleterious PIGQ mutations. Here, we provide the first detailed clinical report of a patient with heterozygous deleterious mutations associated with glycosylphosphatidylinositol‐anchored protein (GPI‐AP) biosynthesis deficiency. Our patient died at 10 months of age. The rare skeletal findings in this disorder expand the differential diagnosis of long bone radiolucent lesions and sphenoid wing dysplasia. This clinical report describes a new and rare disorder—PIGQ GPI‐AP biosynthesis deficiency syndrome. 相似文献