全文获取类型
收费全文 | 119390篇 |
免费 | 6989篇 |
国内免费 | 1585篇 |
专业分类
耳鼻咽喉 | 1575篇 |
儿科学 | 2983篇 |
妇产科学 | 4128篇 |
基础医学 | 18363篇 |
口腔科学 | 3621篇 |
临床医学 | 9328篇 |
内科学 | 21701篇 |
皮肤病学 | 2456篇 |
神经病学 | 8043篇 |
特种医学 | 4025篇 |
外国民族医学 | 4篇 |
外科学 | 16796篇 |
综合类 | 5226篇 |
一般理论 | 34篇 |
预防医学 | 8756篇 |
眼科学 | 2871篇 |
药学 | 10252篇 |
中国医学 | 828篇 |
肿瘤学 | 6974篇 |
出版年
2021年 | 1013篇 |
2019年 | 1055篇 |
2018年 | 1631篇 |
2017年 | 1186篇 |
2016年 | 1211篇 |
2015年 | 1465篇 |
2014年 | 1912篇 |
2013年 | 2489篇 |
2012年 | 3584篇 |
2011年 | 3841篇 |
2010年 | 2314篇 |
2009年 | 2069篇 |
2008年 | 3411篇 |
2007年 | 3642篇 |
2006年 | 3623篇 |
2005年 | 3193篇 |
2004年 | 3008篇 |
2003年 | 2792篇 |
2002年 | 2645篇 |
2001年 | 6732篇 |
2000年 | 6923篇 |
1999年 | 5700篇 |
1998年 | 1836篇 |
1997年 | 1380篇 |
1996年 | 936篇 |
1995年 | 863篇 |
1992年 | 3731篇 |
1991年 | 3807篇 |
1990年 | 3553篇 |
1989年 | 3553篇 |
1988年 | 3428篇 |
1987年 | 3277篇 |
1986年 | 3091篇 |
1985年 | 2968篇 |
1984年 | 2049篇 |
1983年 | 1792篇 |
1982年 | 986篇 |
1979年 | 1910篇 |
1978年 | 1185篇 |
1977年 | 986篇 |
1976年 | 918篇 |
1975年 | 1191篇 |
1974年 | 1359篇 |
1973年 | 1414篇 |
1972年 | 1357篇 |
1971年 | 1247篇 |
1970年 | 1137篇 |
1969年 | 1121篇 |
1968年 | 1024篇 |
1967年 | 897篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Karakas Z Agaoglu L Biner B Devecioglu O Anak S Yalman N Unuvar A Celik A Gedikoglu G 《Acta medica Okayama》2000,54(4):173-177
Fifty-one children (median age: 4.5 years; 4 months-16 years) diagnosed with rhabdomyosarcoma were treated in our center between 1980-1999. The primary sites were head and neck in 31.4%, the genito-urinary system in 21.6%, and extremities in 9.8% of the patients. The histopathologic subtypes were embryonal in 80.4%, alveolar in 9.8%, and undifferentiated in 9.8%. The majority of the patients were considered group III (47%) and group IV (25.5%) according the criteria of the Intergroup Rhabdomyosarcoma Study (IRS). Primary total tumour resection was performed in only 27.5% of the patients. The patients were treated with assigned regimens of IRS II and IRS III protocols. Radiotherapy was applied to 92.1% of the patients. Thirty-four patients (66.7%) were lost to follow up, and of the remaining 17 patients, 7 patients (41.2%) died, relapse occurred in 9 patients (52.9%) and 10 patients (58.8%) are alive. The percentage of cases lost to follow up during the first 10 years and the following 9 years of the study were 77.4% and 50%, respectively. In compliance with cancer treatment remains a major problem in developing countries. 相似文献
992.
993.
Molecular cloning and sequence analysis of full-length cDNAs encoding new group of Cyn d 1 isoallergens 总被引:3,自引:0,他引:3
BACKGROUND: Cyn d 1, the major allergen of Bermuda grass pollen, contains some acidic/basic isoforms. The N-terminal amino acid sequences of some acidic Cyn d 1 isoforms were found to be different from those of Cyn d 1 cDNA clones identified previously. METHODS: A predicted 17-meric oligonucleotide probe was designed to fish the unidentified isoallergen cDNAs out of BGP cDNA library. The reactive clones were isolated and verified by sequencing. Two of them were expressed in the yeast Pichia pastoris to obtain recombinant Cyn d 1 proteins. RESULTS: All four cDNA clones encode the full-length Cyn d 1 with mature proteins of 244 amino acid residues. A 97-99% identity was found among the deduced amino acids of these four clones while an 86% identity was elicited between the four clones and the ones previously identified. The predicted isoelectric focusing (pI) values of the newly identified Cyn d 1s are acidic while pIs of the previously identified Cyn d 1s are basic. The two recombinant acidic Cyn d 1 proteins possess the epitopes recognized by mouse and rabbit polyclonal anti-Cyn d 1 antibodies, and have human IgE-binding capacity as revealed by immunodot assay. CONCLUSIONS: The present study identified full-length cDNAs encoding new isoallergens of Cyn d 1, and separated Cyn d 1 gene into an acidic group and a basic group. 相似文献
994.
995.
Research over the last several decades has led to clear and empirically tractable proposals about the representation of conceptual knowledge in the brain. Here we argue that there are already sufficient data from neuropsychology to strongly constrain extant hypotheses about the representation of conceptual knowledge. One constraint imposed by these neuropsychological data is that recognition of actions and understanding of objects do not necessarily depend on the ability to produce object-associated actions. This conclusion compels a reconsideration of the role played by motor planning and/or execution processes in action and object recognition and understanding. 相似文献
996.
The aim of this study was to evaluate the effect of ten pesticides on Paracoccidioides brasiliensis, and thereby to investigate the possible association between these data and the difficulty in isolating P. brasiliensis from agricultural soil. Six fungicides (Alto 100, Benlate, Captan, Dithane, Plantacol, Rovral), two herbicides (Pivot, Roundup) and two insecticides (Azodrin and Curacron) were evaluated. Five P. brasiliensis isolates from the environment (labelled group 'N,' for 'nature') and five isolates from patients (group 'P'), were grown on Sabouraud's dextrose agar, at 35 degrees C, with ten different concentrations of each pesticide. The dose of pesticide that causes 50% growth inhibition (ED50) was calculated for each isolate. All pesticides assayed inhibited P. brasiliensis in a dose-dependent manner, and great variability among ED50 values was observed in isolates from both groups. No statistically significant difference was observed between averages of ED50 from groups N and P, except with Alto 100. The inhibitory effect of pesticides on P. brasiliensis suggests that they can interfere with attempts to isolate P. brasiliensis from soil, where tonnes of pesticides are applied over large areas planted with various crops. 相似文献
997.
Results of treatment of 13 patients fulfilling the criteria for TTP are presented. Thrombocytopenia was present in all patients (100%). Eleven of 13 patients (84.6%) had conciousness disorder, and seven of 13 patients (53.8%) had renal impairment. Immunosuppressive therapy with plasmapheresis and replacement of removed volume with fresh frozen plasma in a dosage of 25 ml/kg body weight resulted in statistically significant increase of platelet count (p = 0.0033), and significant improvement of consciousness as defined by increased Glasgow Coma Score (GCS) (p = 0.0524). In two patients, renal function recovered and, in one patient, hemodialysis was no longer needed. This improvement in a small patient group has no statistical significance. 相似文献
998.
Ar+ ion beam sputtering/mixing deposition was used to produce thin calcium phosphate coatings on titanium substrate from hydroxyl-poly-calcium sodium phosphate (HPPA) and HPPA + Ti targets. Three types of coatings (one type of monolayer coating and two types of functionally graded coating) were manufactured. It was found that as-sputtered coatings were amorphous. No distinct hydroxyl band was observed in the FTIR spectra, but new absorption bands were determined for CO3(2-), which resulted during the deposition process. Compositional gradients from the surface to the interior (i.e. adjacent to the substrate) were achieved for the functionally graded coatings. Post-deposition heat treatment indicated that the bonding strength between the coating and the substrate was improved by the use of functionally graded structures. 相似文献
999.
Neutralization of myxoviruses by anticellular sera 总被引:1,自引:0,他引:1
1000.
New Nocardia taxon among isolates of Nocardia brasiliensis associated with invasive disease. 总被引:5,自引:6,他引:5 下载免费PDF全文
R J Wallace Jr B A Brown Z Blacklock R Ulrich K Jost J M Brown M M McNeil G Onyi V A Steingrube J Gibson 《Journal of clinical microbiology》1995,33(6):1528-1533
Nocardia brasiliensis, the second most frequently isolated aerobic actinomycete in the clinical laboratory, is usually associated with localized cutaneous infections. However, 22% of 238 N. brasiliensis isolates from the United States and 12% of 66 isolates from Queensland, Australia, which had been collected over a 17-year period, were associated with extracutaneous and/or disseminated diseases. Of the 62 invasive isolates, 37 (60%) were susceptible to ciprofloxacin and/or were susceptible to clarithromycin and resistant to minocycline, compared with only 6 (3%) of 242 localized cutaneous isolates. The 43 isolates with this susceptibility pattern appeared to define a new taxon. They were similar to Nocardia asteroides complex isolates clinically in proportions from persons with pulmonary (70%), central nervous system (23%), and/or disseminated diseases (37%) in the setting of corticosteroids (74%) or AIDS (14%). This putative new taxon differed from N. brasiliensis in the hydrolysis of adenine (92 versus 4%), beta-lactamase patterns on isoelectric focusing, and the presence of two early mycolic acid-ester peaks by high-performance liquid chromatography. Restriction analysis of a 439-bp fragment of the 65-kDa heat shock protein gene revealed that N. brasiliensis and the new taxon had different restriction patterns with 8 of the 11 enzymes tested. Screening of invasive isolates of N. brasiliensis for susceptibility to ciprofloxacin will identify most isolates of the new taxon, which likely represents a new Nocardia species. 相似文献