全文获取类型
收费全文 | 6195篇 |
免费 | 325篇 |
国内免费 | 69篇 |
专业分类
耳鼻咽喉 | 102篇 |
儿科学 | 87篇 |
妇产科学 | 91篇 |
基础医学 | 704篇 |
口腔科学 | 142篇 |
临床医学 | 436篇 |
内科学 | 2057篇 |
皮肤病学 | 85篇 |
神经病学 | 742篇 |
特种医学 | 235篇 |
外科学 | 865篇 |
综合类 | 26篇 |
预防医学 | 223篇 |
眼科学 | 52篇 |
药学 | 331篇 |
中国医学 | 21篇 |
肿瘤学 | 390篇 |
出版年
2023年 | 44篇 |
2022年 | 98篇 |
2021年 | 148篇 |
2020年 | 100篇 |
2019年 | 123篇 |
2018年 | 181篇 |
2017年 | 145篇 |
2016年 | 154篇 |
2015年 | 162篇 |
2014年 | 224篇 |
2013年 | 338篇 |
2012年 | 477篇 |
2011年 | 454篇 |
2010年 | 283篇 |
2009年 | 260篇 |
2008年 | 391篇 |
2007年 | 376篇 |
2006年 | 356篇 |
2005年 | 392篇 |
2004年 | 341篇 |
2003年 | 280篇 |
2002年 | 236篇 |
2001年 | 105篇 |
2000年 | 98篇 |
1999年 | 104篇 |
1998年 | 37篇 |
1997年 | 43篇 |
1996年 | 41篇 |
1995年 | 42篇 |
1994年 | 25篇 |
1993年 | 20篇 |
1992年 | 46篇 |
1991年 | 52篇 |
1990年 | 39篇 |
1989年 | 37篇 |
1988年 | 47篇 |
1987年 | 32篇 |
1986年 | 28篇 |
1985年 | 29篇 |
1984年 | 26篇 |
1983年 | 22篇 |
1981年 | 11篇 |
1980年 | 9篇 |
1979年 | 16篇 |
1978年 | 11篇 |
1975年 | 9篇 |
1974年 | 14篇 |
1970年 | 12篇 |
1969年 | 9篇 |
1968年 | 9篇 |
排序方式: 共有6589条查询结果,搜索用时 15 毫秒
41.
Maurizio Iaria Carlo Pellegrino Elena Cremaschi Enzo Capocasale Raffaele Dalla Valle Paolo Del Rio Carmelo Puliatti 《Transplantation proceedings》2021,53(3):1055-1057
BackgroundLymphatic disorders (LDs) are the most common minor complications after kidney transplantation (KT), with an incidence rate between 0.6% and 33.9%, which appears to be related to both surgical and medical factors. LDs mostly resolve spontaneously, but occasionally a surgical approach may be required.Materials and MethodsWe report our experience with 7 KT recipients who developed persistent lymphorrhea (>150 mL/24 h) between October 2017 and March 2019. All cases were treated as outpatients with parietal fistulectomy (PF). The fibrotic aponeurotic-cutaneous tract was thoroughly excised, and the residual aponeurotic defect was closed by watertight suturing. Serial abdominal ultrasounds (US) were carried out after the procedure.ResultsA small perirenal graft lymphocele of <2 cm was detected by US in all patients after 48 to 72 hours, without any evidence of either vascular or ureteral compression. During the subsequent scheduled US follow-up, lymphoceles did not increase in size, and additional interventions were not needed. Neither superficial nor deep surgical-site infections were recorded in such patients.ConclusionsPF was found to be a safe and effective minimally invasive approach for persistent lymphorrhea after KT. It could be easily performed with local anesthesia in a day surgery setting and did not require patient hospitalization. 相似文献
42.
Francisco A. Ferri Joel S. Frieder David Gutierrez Blanco David Romero Funes Camila Ortiz Gomez Emanuele Lo Menzo Samuel Szomstein Raul J. Rosenthal 《Surgery for obesity and related diseases》2021,17(2):284-291
BackgroundSleeve gastrectomy (SG) has become the most prevalent bariatric-metabolic surgical approach in the United States. Its popularity among surgeons and patients is mainly due to a better safety profile and less overall morbidity, with broad benefits from a systemic and metabolic perspective.ObjectiveComprehensively describe the short-term multiorgan metabolic effects of rapid weight loss after SG.SettingAcademic hospital, United States.MethodsWe retrospectively reviewed the charts of patients that underwent SG at our institution between 2012 and 2016. We analyzed the required variables to calculate multiple risk scores, such as cardiovascular, hypertension, and diabetes risk scores. Furthermore, the renal and hepatic functions and the metabolic and hematologic profiles were assessed at 12 months of follow-up.ResultsA total of 1002 patients were included in the analysis. The percentage of excess body mass index loss was, on average, 65% at 12 months of follow-up. We observed a positive cardio-renal-hepatic improvement, demonstrated by a substantial reduction of the 10-year cardiovascular risk. We noticed an improvement of renal function, which was more significant in chronic kidney disease (stage ≥2), and a significant improvement on liver function tests (measured by decreased aspartate aminotransferase and alanine transaminase) at 12 months of follow-up. Our data also show a positive impact on decreasing the risk of developing hypertension and type 2 diabetes. There was a positive impact on the lipid profile, with the exception of low-density lipoprotein.ConclusionThere are significant short-term benefits on multiorgan metabolic parameters after rapid weight loss in severely obese patients undergoing sleeve gastrectomy. 相似文献
43.
44.
Salvatore Cicciarello Guglielmo Borgia Jane Crowell Rocco Ciampi Raimondo Cerini Raffaele Orlando Michelina Mainolfi Laura Reynaud Michele Milano Marcello Piazza 《European journal of epidemiology》1997,13(1):49-54
HCV is ubiquitous. In 50% of all cases it causes chronic hepatitis that often evolves into liver cirrhosis and hepatocellular carcinoma. Recently HCV has been classified in 5 genotypes by Okamoto. The purpose of this study is to evaluate the prevalence of 5 genotypes in Campania, a region of Southern Italy, where the prevalence of anti-HCV antibodies ranges from 0.87 to 4%, and to evaluate the correlation between the HCV genotypes and the severity of histological damage. One hundred and thirty-five anti-HCV positive patients were enrolled and tested by PCR to identify HCV-RNA. One hundred and twenty-four patients resulted HCV-RNA positive. Genotyping was performed as described by Okamoto et al. with minor modifications of the specific primer to type III proposed by Silini et al. Eight patients were negative for all genotypes. Eight patients were positive for type I(1a), 61 for type II(1b), 39 for type III(2a), 11 for type IV(2b) and 1 for type V(3a). In 4 cases two different genotypes were present in the same sample [II(1b)-IV(2b), III(2a)-II(1b) twice, III(2a)-IV(2b)]. Histological evaluation of liver damage showed: CPH (22 cases), minimal CAH (56), severe CAH (31) and liver cirrhosis (15). There was no statistically significant correlation between the 5 genotypes and the severity of histological damage. Data on the prevalence of genotype II(1b) in Italy are similar to those reported for other European countries. The prevalence of genotypes in Southern Italy is similar to that reported in the population of Northern Italy. 相似文献
45.
Barletta A Ferri G Assennato G Poti S Wiesel S Losito V Paradiso A 《Oncology reports》1995,2(2):289-294
The qualitative results of FCM DNA analysis on fresh and fixed urine specimens (28 and 97, respectively) from 68 normal subjects and 10 patients with a past history of bladder cancer were compared. FCM DNA evaluability was not significantly different in fresh and fixed samples (63% vs 73%, respectively) whereas mean CV was significantly higher (7.3% vs 5.7%, respectively; p=0.04). A double FCM analysis on fresh and fixed urine was also performed in 16 cases. In this subgroup, the percentage of evaluable histograms from fixed urine specimens was slightly higher than that from fresh specimens. Aneuploid cases were found only in the fixed urine samples but the CVs from fresh and fixed cell suspensions did not differ. The absence of inflammatory cells with cytological analysis of the same samples was associated with low percentages of FCM evaluability and higher CVs. The use of fixed samples improves the quality of FCM DNA analysis permitting its use for screening programs. 相似文献
46.
Gaudichon C Mahé S Benamouzig R Luengo C Fouillet H Daré S Van Oycke M Ferrière F Rautureau J Tomé D 《The Journal of nutrition》1999,129(4):890-895
The aim of this study was to follow the fate of dietary nitrogen to assess the postprandial utilization of purified milk protein and to determine the acute influence of energy nutrients. For this purpose, a [15N]-labeling dietary protein approach was used. Twenty-five subjects swallowed an ileal tube and ingested [15 N]-milk protein alone or supplemented with either milk fat or sucrose. The absorption and postprandial deamination of dietary protein was monitored for 8 h. Sucrose delayed the absorption of protein longer than fat, but the ileal digestibility did not differ among groups (94.5-94.8%). Sucrose, but not fat, significantly reduced the postprandial transfer of [15N]-milk nitrogen to urea. Consequently, the net postprandial protein utilization (NPPU) of milk protein calculated 8 h after meal ingestion was 80% when ingested either alone or supplemented with fat and was significantly greater with sucrose (NPPU = 85%). This study shows that energy nutrients do not affect the nitrogen absorption but modify the metabolic utilization of dietary protein in the phase of nitrogen gain. Our method provides information concerning the deamination kinetics of dietary amino acids and further allows the detection of differences of dietary protein utilization in acute conditions. The diet composition should be carefully considered, and protein quality must be determined under optimal conditions of utilization. 相似文献
47.
48.
Lang T Ducimetière P Arveiler D Amouyel P Ferrières J Ruidavets JB Montaye M Haas B Bingham A 《International journal of epidemiology》1999,28(6):1050-1058
OBJECTIVES: To assess whether different definitions of acute coronary events yielded concordant results concerning trends and geographical disparities in coronary heart disease (CHD) mortality and morbidity in France. STUDY DESIGN: Data from three French CHD registries participating in the WHO MONICA Project during the period 1985-1992. SETTING: Three areas of about one million inhabitants each in the North, South and East of France. SUBJECTS: About 2,000 acute coronary events each year. MAIN OUTCOME MEASURES: Mortality, annual rate of fatal and non-fatal events, incidence of first and recurrent events, case-fatality rates. RESULTS: For incidence and mortality, the broader the broader the definition of the acute event, the higher the reported rates. The same tendency was not observed for case-fatality rates. Comparing between-registry rates for mortality, 28-day case-fatality and hospital case fatality yielded relatively concordant results whatever the definition of event. As a whole, the higher mortality rate in Lille and its intermediate rank in Strasbourg were related more to disparities in case-fatality rates, with only small variations in incidence rates, independently of the definition used. Comparing temporal trends in rates within and between regions, a consistent decrease in annual mortality rates and case-fatality rates was observed, whatever the definition. In contrast, the incidence of non-fatal probable myocardial infarction did not change during the period in any register. CONCLUSIONS: Although the absolute estimates of rates were variable with the definition of the event, major findings in relation to trends and geographical disparities were fairly consistent across the definitions: the North-South gradient in mortality observed in France was found to be much more pronounced for case fatality than for incidence. The proportion of milder acute myocardial infarction is currently increasing and this element should be taken into account when analysing CHD rates. 相似文献
49.
vgf is an inducible gene, highly sensitive to nerve growth factor (NGF) and remarkably upregulated in the "early-delayed" phase of response (within a few hours). It encodes a 617-amino acid polypeptide (VGF protein) bearing no significant homology with known sequences and restricted to certain peptide/amine-producing endocrine cells, and neurons (for example, adenohypophysial and adrenal medullary cells, or hypothalamic neuroendocrine neurons). VGF is stored and transported in secretory granules and processed to intermediate-small molecular weight products, which are preferentially released. Striking changes in both VGF mRNA and immunolocalization are found in physiological conditions (for example, estrous cycle) and in experimental models of stimulation affecting hypothalamic and other neurons. Functional roles of VGF are to be sought in secretory granule formation and regulation, and/or in the production of potentially bioactive peptides. 相似文献
50.
De Caro R Raffaele De Caro Parenti A Montisci M Guidolin D Macchi V 《Stroke; a journal of cerebral circulation》2000,31(5):1187-1193
BACKGROUND AND PURPOSE: Symmetrical necrosis of the brain stem nuclei has been described as a consequence of severe transitory cerebral hypoxia mainly in neonates or young adults who experienced an episode of acute ischemia due to transitory acute heart failure. We report selective bilateral lesions of the solitary tract nuclei in 5 adults with short survival intervals after acute heart failure. METHODS: In 5 patients who died due to cardiovascular pathology, histological examination was performed on multiple samples of cerebral hemispheres, on transverse sections of the midbrain and pons, and on transverse serial sections of the medulla stained with hematoxylin-eosin, Klüver-Barrera, and Luxol fast blue. The 3-dimensional reconstruction of the extension and topography of the medullary lesions was obtained with computed image analysis. RESULTS: In 4 subjects who died soon after an episode of acute heart failure (range of survival 10 hours to 2 days), the dorsal portion of the solitary tract nuclei showed an eosinophilic roundish aspect bilaterally. In their context, the neurons showed changes characteristic of ischemic coagulation necrosis. In a fifth patient, a 32-year-old man who died 15 days after an episode of cardiac arrest, 2 circumscribed symmetrical infarcts with macrophagic and astrocytic reactions were found at the same level. The topography of the lesions and the inflammatory reaction and gliosis of patient 5 suggest that the findings in the other 4 patients correspond to initial features of selective lesions of the solitary tract nuclei after acute heart failure: the short interval of survival prevented the evolution of the reactive process. The nucleus is localized at the watershed zone between the terminal branches of the medullary collateral vessels of the vertebral arteries, thus representing the last meadow in the case of sudden fall of the systemic blood flow due to acute heart failure. The absence of lesions of other medullary and pontine nuclei accounts for a selective vulnerability of the neurons of the solitary tract nuclei, and the selective dendritic lesions suggest an excitotoxic component to ischemic cell death. CONCLUSIONS: The commonly accepted resistance of the medullary centers to ischemic hypoxia in adults apparently could be due to the rapidity of death, which prevents the evolution of lesions that can be diagnosed. In addition, minor lesions in the medullary tegmentum after acute heart failure could play a role in the prevention of the resumption of autonomous cardiac and respiratory functions despite life-saving procedures. 相似文献