全文获取类型
收费全文 | 8685篇 |
免费 | 429篇 |
国内免费 | 78篇 |
专业分类
耳鼻咽喉 | 108篇 |
儿科学 | 174篇 |
妇产科学 | 52篇 |
基础医学 | 914篇 |
口腔科学 | 206篇 |
临床医学 | 534篇 |
内科学 | 2303篇 |
皮肤病学 | 81篇 |
神经病学 | 619篇 |
特种医学 | 450篇 |
外科学 | 1709篇 |
综合类 | 52篇 |
预防医学 | 242篇 |
眼科学 | 269篇 |
药学 | 491篇 |
中国医学 | 15篇 |
肿瘤学 | 973篇 |
出版年
2023年 | 97篇 |
2022年 | 212篇 |
2021年 | 310篇 |
2020年 | 140篇 |
2019年 | 189篇 |
2018年 | 260篇 |
2017年 | 208篇 |
2016年 | 259篇 |
2015年 | 255篇 |
2014年 | 305篇 |
2013年 | 366篇 |
2012年 | 553篇 |
2011年 | 628篇 |
2010年 | 317篇 |
2009年 | 271篇 |
2008年 | 493篇 |
2007年 | 503篇 |
2006年 | 489篇 |
2005年 | 454篇 |
2004年 | 412篇 |
2003年 | 384篇 |
2002年 | 380篇 |
2001年 | 163篇 |
2000年 | 127篇 |
1999年 | 117篇 |
1998年 | 70篇 |
1997年 | 62篇 |
1996年 | 66篇 |
1995年 | 42篇 |
1994年 | 68篇 |
1993年 | 36篇 |
1992年 | 92篇 |
1991年 | 82篇 |
1990年 | 92篇 |
1989年 | 89篇 |
1988年 | 84篇 |
1987年 | 63篇 |
1986年 | 72篇 |
1985年 | 57篇 |
1984年 | 30篇 |
1983年 | 26篇 |
1982年 | 14篇 |
1980年 | 15篇 |
1979年 | 28篇 |
1978年 | 14篇 |
1977年 | 21篇 |
1974年 | 16篇 |
1971年 | 20篇 |
1969年 | 17篇 |
1968年 | 15篇 |
排序方式: 共有9192条查询结果,搜索用时 15 毫秒
101.
102.
Uemura T Nikkel LE Hollenbeak CS Ramprasad V Schaefer E Kadry Z 《Transplant international》2012,25(6):671-679
Advanced age donors have inferior outcomes of liver transplantation for Hepatitis C (HCV). Aged donors grafts may be transplanted into young or low model for end stage liver disease (MELD) patients in order to offset the effect of donor age. However, it is not well understood how to utilize liver grafts from advanced aged donors for HCV patients. Using the UNOS database, we retrospectively studied 7508 HCV patients who underwent primary liver transplantation. Risk factors for graft failure and graft survival using advanced aged grafts (donor age ≥ 60 years) were analyzed by Cox hazards models, donor risk index (DRI) and organ patient index (OPI). Recipient's age did not affect on graft survival regardless of donor age. Advanced aged grafts had significant inferior survival compared to younger aged grafts regardless of MELD score (P < 0.0001). Risk factors of HCV patients receiving advanced aged grafts included donation after cardiac death (DCD, HR: 1.69) and recent hospitalization (HR: 1.43). Advanced aged grafts showed significant difference in graft survival of HCV patients with stratification of DRI and OPI. In conclusion, there was no offsetting effect by use of advanced aged grafts into younger or low MELD patients. Advanced aged grafts, especially DCD, should be judiciously used for HCV patients with low MELD score. 相似文献
103.
Comparison of grey matter and metabolic reductions in frontotemporal dementia using FDG-PET and voxel-based morphometric MR studies 总被引:1,自引:0,他引:1
Kanda T Ishii K Uemura T Miyamoto N Yoshikawa T Kono AK Mori E 《European journal of nuclear medicine and molecular imaging》2008,35(12):2227-2234
Purpose The aim of this study was to investigate the regional differences between the morphologic and functional changes in the same
patients with frontotemporal dementia (FTD) using statistical parametric mapping and voxel-based morphometry (VBM).
Methods Thirteen FTD patients (mean age, 64.9 years old; mean MMSE score, 17.7), 20 sex-matched Alzheimer’s disease (AD) patients
(mean age, 65.0 years old; mean MMSE score, 17.5), and 20 normal volunteers (mean age, 65.2 years old; mean MMSE score, 29.0)
underwent both [18F]FDG positron emission tomography and three-dimensional spoiled gradient echo MRI. Statistical parametric mapping was used
to conduct a VBM analysis of the morphologic data, which were compared voxel by voxel with the results of a similar analysis
of glucose metabolic data.
Results FTD patients showed decreased grey matter volume and decreased glucose metabolism in the frontal lobe and anterior temporal
lobe. In addition, there was a clear asymmetry in grey matter volume in FTD patients by the VBM analysis while the glucose
metabolic data showed little asymmetry. In AD patients, glucose metabolic reduction occurred in the bilateral posterior cingulate
gyri and parietal lobules while grey matter density decreased the least in the same patients.
Conclusion In FTD, metabolic and morphologic changes occur in the bilateral frontal lobe and temporal lobe with a limited asymmetry whereas
there was considerable discordance in the AD group. 相似文献
104.
Ishii K Kanda T Harada A Miyamoto N Kawaguchi T Shimada K Ohkawa S Uemura T Yoshikawa T Mori E 《European radiology》2008,18(11):2678-2683
The utility of measuring the corpus callosal angle (CA) for the diagnosis of idiopathic normal pressure hydrocephalus (INPH)
was investigated. Three-dimensional magnetic resonance imaging (MRI) was performed in 34 INPH patients, 34 Alzheimer’s disease
(AD) patients, and 34 normal control (NC) subjects. Measurement of the CA on the coronal MR images of the posterior commissure
perpendicular to the anteroposterior commissure plane was performed for all subjects. The CA of the INPH group (mean ± SD,
66 ± 14°) was significantly smaller than those of the AD (104 ± 15°) and NC (112 ± 11°) groups. When using the threshold of
the mean − 2SD value of the NC group (= 90°), an accuracy of 93%, sensitivity of 97%, and specificity of 88% were observed
for discrimination of INPH from AD patients. Measuring the CA helps in differentiating INPH patients from AD and normally
aged subjects. 相似文献
105.
Maruyama K Iijima K Ikeda M Kitamura A Tsukaguchi H Yoshiya K Hoshii S Wada N Uemura O Satomura K Honda M Yoshikawa N 《Pediatric nephrology (Berlin, Germany)》2003,18(5):412-416
Podocin is an integral membrane protein encoded by NPHS2, which is mapped to 1q25-31 and is exclusively expressed in glomerular podocytes. NPHS2 mutations are responsible for autosomal recessive familial steroid-resistant nephrotic syndrome (SRNS) with minor glomerular abnormalities or focal segmental glomerulosclerosis (FSGS), which is characterized by early childhood onset (age less than 6 years) and rapid progression to chronic renal insufficiency. This gene mutation is also responsible for an adolescent/adult onset form of autosomal recessive familial FSGS with heavy proteinuria. It has been demonstrated that sporadic SRNS and heavy proteinuria are also due to NPHS2 gene mutations. We isolated genomic DNA from 36 Japanese children with chronic renal insufficiency caused by SRNS or heavy proteinuria, and analyzed all eight exons and exon-intron boundaries of NPHS2 using the polymerase chain reaction and direct sequencing. The age at onset of disease was 3.9+/-0.5 years. There were 29 patients with SRNS and 7 with heavy proteinuria without nephrotic syndrome at the onset, but all patients developed chronic renal insufficiency 4.6+/-0.8 years after the onset. A new homozygous missense variant of NPHS2, G34E (G101A) in exon 1, was detected in 1 of 36 patients. However, this homozygous variant was also found in 1 of 44 normal controls, suggesting that the mutation is a polymorphism. Two silent variants (T954C and A1038G) in exon 8 of this gene were also identified in some of the patients and normal controls, indicating that the silent variants are also polymorphisms. There was no significant difference in the genotypic and allelic frequencies of T954C and A1038G polymorphisms between the patients and normal controls. In conclusion, NPHS2 gene mutations are not a major cause of chronic renal insufficiency caused by sporadic SRNS or heavy proteinuria in Japanese children. 相似文献
106.
Prophylaxis of nausea and vomiting after laparoscopic cholecystectomy with ramosetron: randomised controlled trial. 总被引:2,自引:0,他引:2
OBJECTIVE: To evaluate the efficacy and safety of ramosetron (a 5-hydroxytryptamine type 3 receptor antagonist) for the prevention of nausea and vomiting after laparoscopic cholecystectomy. DESIGN: Prospective, randomised, double-blind, placebo-controlled study. SETTING: University and university-affiliated hospitals, Japan. SUBJECTS: 100 patients, 65 women and 35 men, who had laparoscopic cholecystectomy. INTERVENTIONS: Patients were given either placebo or ramosetron at 3 different doses (0.15 mg, 0.3 mg, 0.6 mg) intravenously at the completion of operation. The general anaesthetic technique and postoperative analgesia were standard. MAIN OUTCOME MEASURES: Vomiting and safety were assessed for 0 to 24 hours and 24 to 48 hours after anaesthesia. RESULTS: The number of patients who had a complete response (no nausea, no retching, no vomiting) during 0 to 24 hours after anaesthesia was 15/25 with placebo, 17/25 with ramosetron 0.15 mg, 23/25 with ramosetron 0.3 mg, and 23/25 with ramosetron 0.6 mg; The corresponding numbers from 24 to 48 hours were 16, 17, 23, and 23. No serious adverse events were observed in any of the groups. CONCLUSIONS: Ramosetron 0.3 mg was the minimum effective dose for preventing postoperative nausea and vomiting during 0 to 48 hours after anaesthesia in patients undergoing laparoscopic cholecystectomy. 相似文献
107.
Background. Diaphragmatic fatigue is implicated as a cause ofrespiratory failure. This study was undertaken to evaluate theeffects of inhaled olprinone, a newly developed phosphodiesteraseIII inhibitor, on the contractility of fatigued diaphragm indogs. Methods. Diaphragmatic fatigue was induced by intermittent supramaximalbilateral electrophrenic stimulation at a frequency of 20 Hzstimulation applied for 30 min. When fatigue was established,group I (n=8) received inhaled vehicle; group II (n=8) receivedinhaled olprinone 1 mg; group III (n=8) received inhaled olprinone2 mg. Diaphragmatic contractility was assessed by transdiaphragmaticpressure (Pdi, cm H2O). Results. In the presence of fatigue, in each group, Pdi at low-frequency(20 Hz) stimulation decreased from baseline values (P<0.05),whereas Pdi at high-frequency (100 Hz) stimulation did not change.In groups II and III, during olprinone administration, Pdi atboth stimuli increased from fatigued values (20 Hz stimulation:group II (mean (SD)) 10.8 (1.0) to 12.5 (1.3), group III 10.9(1.7) to 15.0 (3.0); 100 Hz stimulation: group II 20.1 (1.9)to 22.6 (1.3), group III 20.6 (2.0) to 24.5 (2.0), P<0.05).The increase in Pdi was larger in group III than in group II(P<0.05). Conclusions. Inhaled olprinone produces a dose-dependent improvementin contractility of fatigued canine diaphragm. Br J Anaesth 2002; 88: 40811 相似文献
108.
Distinct Recurrence Pattern and Outcome of Adenocarcinoma of the Gastric Cardia in Comparison with Carcinoma of Other Regions of the Stomach 总被引:4,自引:0,他引:4
Saito H Fukumoto Y Osaki T Fukuda K Tatebe S Tsujitani S Ikeguchi M 《World journal of surgery》2006,30(10):1864-1869
Background Carcinoma arising in the cardioesophageal junction is a distinct clinical entity compared with tumors located in other regions
of the stomach. The prognosis for adenocarcinoma of the upper stomach is considered to be relatively poorer than carcinomas
of the more distal stomach. We have therefore investigated patients with carcinoma of the gastric cardia in order to evaluate
the underlying cause of this poor prognosis.
Materials and Methods Clinicopathologic features and postoperative prognosis of 101 patients with carcinoma of the cardia were evaluated and compared
with findings on 1884 patients with tumors in other regions of the stomach.
Results Tumors of the cardia had a mean size of 6.8 cm, which was significantly larger than the mean size of 5.9 cm for tumors found
in the middle- and lower third of the stomach. The incidence of serosal invasion, lymph node metastasis, and lymphatic and
blood vessel invasion was higher in association with adenocarcinoma of the cardia than with adenocarcinoma in remaining parts
of the stomach. In the analysis of patients who had undergone curative resection, the 5-year survival rates were 61.6, 79.1,
and 82.6% in patients with carcinoma of the cardia, upper one-third, and remaining middle- and lower one-third of the stomach,
respectively, and the differences were statistically significant. Multivariate analysis indicated that adenocarcinoma of the
gastric cardia is an independent prognostic factor. With regard to the site of recurrence, both lymph node and hematogenous
recurrence were observed more frequently in the cardia than in the remaining parts of the stomach.
Conclusions Our data indicate that the prognosis of patients with adenocarcinoma of the gastric cardia is extremely poor. To improve their
prognosis, new treatments in addition to gastrectomy with extensive lymph node dissection are needed. 相似文献
109.
Tetsuhiko Mimura Shigeharu Uchiyama Masanori Hayashi Kazutaka Uemura Hideki Moriya Hiroyuki Kato 《Journal of orthopaedic science》2017,22(6):1026-1030
Background
During the surgery for a distal radius fracture, we encountered a large anomalous muscle lying across the distal radius. The muscle was identified as a flexor carpi radialis brevis muscle (FCRB), based on its location, function, and innervation. This experience led us to clarify its prevalence in living subjects and alert surgeons of its presence.Methods
We reviewed wrist MRI scans of 515 hands of 379 patients with carpal tunnel syndrome (CTS). The prevalence of the FCRB was calculated. The cross sectional area (CSA) of the FCRB was compared with that of the hypothenar muscles. Signal intensity and fat infiltration of the FCRB were assessed using semiquantitative methods. The anterior compartment ratio (CSA of the anterior compartment of the forearm was divided by CSA of the forearm. CSA of the FCRB was excluded for measurement) was compared between patients with and without FCRB.Results
We found seven hands of six patients (1.6%) with a FCRB. All of these tendons were inserted into the second metacarpal base. CSA of FCRB was smaller than that of the hypothenar muscles. Semiquantitative assessment revealed normal signal intensities of the FCRB compared with those of other muscles. The anterior compartment ratio was smaller in patients with FCRB than without FCRB. None of the FCRB in our series demonstrated any sign of tendinitis on MRI. Furthermore, the postoperative clinical course for those patients was uneventful.Conclusions
Prevalence of FCRB in patients with CTS was 1.6%. FCRB should function as a wrist flexor. Its strength varied according to the individuals but was not greater than that of the hypothenar muscles. It is still unclear if the FCRB could cause the development of CTS. However, it was found that the FCRB could be a mass which occupies and narrows the anterior compartment. 相似文献110.
Ryu?Kanzaki Masayoshi?InoueEmail author Masato?Minami Yasushi?Shintani Soichiro?Funaki Tomohiro?Kawamura Meinoshin?Okumura 《Surgery today》2017,47(1):27-34