首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   4640篇
  免费   203篇
  国内免费   35篇
耳鼻咽喉   61篇
儿科学   39篇
妇产科学   79篇
基础医学   572篇
口腔科学   69篇
临床医学   311篇
内科学   1227篇
皮肤病学   92篇
神经病学   279篇
特种医学   227篇
外科学   803篇
综合类   12篇
预防医学   93篇
眼科学   107篇
药学   232篇
中国医学   11篇
肿瘤学   664篇
  2023年   44篇
  2022年   54篇
  2021年   161篇
  2020年   97篇
  2019年   122篇
  2018年   134篇
  2017年   98篇
  2016年   106篇
  2015年   125篇
  2014年   159篇
  2013年   184篇
  2012年   306篇
  2011年   315篇
  2010年   198篇
  2009年   157篇
  2008年   280篇
  2007年   302篇
  2006年   286篇
  2005年   282篇
  2004年   253篇
  2003年   227篇
  2002年   234篇
  2001年   63篇
  2000年   68篇
  1999年   57篇
  1998年   33篇
  1997年   39篇
  1996年   45篇
  1995年   41篇
  1994年   36篇
  1993年   19篇
  1992年   25篇
  1991年   21篇
  1990年   25篇
  1989年   31篇
  1988年   29篇
  1987年   19篇
  1986年   35篇
  1985年   24篇
  1984年   22篇
  1983年   11篇
  1982年   13篇
  1981年   16篇
  1980年   7篇
  1979年   13篇
  1977年   9篇
  1976年   6篇
  1975年   7篇
  1974年   6篇
  1973年   8篇
排序方式: 共有4878条查询结果,搜索用时 31 毫秒
51.
BACKGROUNDPreoperative portal vein embolization (PVE) is a widely used strategy to enable major hepatectomy in patients with insufficient liver remnant. PVE induces hypertrophy of the future liver remnant (FLR) and a shift of the functional reserve to the FLR. However, whether the increase of the FLR volume (FLRV) corresponds to the functional transition after PVE remains unclear.AIMTo investigate the sequential relationship between the increase in FLRV and functional transition after preoperative PVE using 3-dimensional (3D) computed tomography (CT) and 99mTc-galactosyl-human serum albumin (99mTc-GSA) single-photon emission computed tomography (SPECT) fusion images. METHODSThirty-three patients who underwent major hepatectomy following PVE at the Department of Gastroenterological Surgery I, Hokkaido University Hospital between October 2013 and March 2018 were enrolled. Three-phase dynamic multidetector CT and 99mTc-GSA SPECT scintigraphy were performed at pre-PVE, and at 1 and 2 wk after PVE; 3D 99mTc-GSA SPECT CT-fused images were constructed from the Digital Imaging and Communications in Medicine data using 3D image analysis system. Functional FLRV (FFLRV) was defined as the total liver volume × (FLR volume counts/total liver volume counts) on the 3D 99mTc-GSA SPECT CT-fused images. The calculated FFLRV was compared with FLRV.RESULTSFFLRV increased by a significantly larger extent than FLRV at 1 and 2 wk after PVE (P < 0.01). The increase in FFLRV and FLRV was 55.1% ± 41.6% and 26.7% ± 17.8% (P < 0.001), respectively, at 1 wk after PVE, and 64.2% ± 33.3% and 36.8% ± 18.9% (P < 0.001), respectively, at 2 wk after PVE. In 3 of the 33 patients, FFLRV levels decreased below FLRV at 2 wk. One of the three patients showed rapidly progressive fatty changes in FLR. The biopsy at 4 wk after PVE showed macro- and micro-vesicular steatosis of more than 40%, which improved to 10%. Radical resection was performed at 13 wk after PVE. The patient recovered uneventfully without any symptoms of pos-toperative liver failure.CONCLUSIONThe functional transition lagged behind the increase in FLRV after PVE in some cases. Evaluating both volume and function is needed to determine the optimal timing of hepatectomy after PVE.  相似文献   
52.
BackgroundThe clinical benefit of the combined androgen blockade (CAB) therapy over luteinizing hormone-releasing hormone analog (LH-RHa) monotherapy for hormone naïve metastatic prostate cancer (mHNPC) is unclear. Therefore, we retrospectively compare the effectiveness of CAB with the LH-RHa monotherapy on the prognosis of Japanese patients with mHNPC.MethodsWe retrospectively evaluated the prognosis of 517 patients diagnosed with mHNPC between August 2001 and May 2017. The patients’ data were obtained from the Michinoku Urological Cancer Research Group database and Hirosaki University-related hospitals. Patients were divided into the CAB and LH-RHa monotherapy groups based on primary androgen deprivation therapy (ADT). Overall survival (OS), cancer-specific survival (CSS), and castrate-resistant prostate cancer-free survival (CRPC-FS) were compared between the two groups using the Kaplan-Meier curve analysis. Inverse probability of treatment weighting (IPTW)-adjusted Cox hazard proportional analyses was performed to investigate the effect of primary ADT on oncological outcomes.ResultsThe median age was 73 years old. The numbers of patients in the CAB and LH-RHa monotherapy groups were 447 and 70, respectively. The Kaplan-Meier curve analysis showed no significant differences in either 5-year OS (56.7% vs. 52.5%, P=0.277), CSS (61.1% vs. 56.4%, P=0.400), and CRPC-FS (33.1% vs. 31.1%, P=0.529) between the groups. IPTW-adjusted multivariate Cox hazard proportional analyses showed no significant differences in OS, CSS, and CRPC-FS between the two groups.ConclusionsNo significant differences in oncological outcomes were observed between the CAB and LH-RHa monotherapy groups in patients with mHNPC.  相似文献   
53.
The purpose of this study was to describe the results of definitive radiotherapy (RT) with concurrent chemotherapy for maxillary sinus carcinomas (MSCs) with neck lymph node metastasis to clarify its limitation. Local control (LC), progression-free survival (PFS) and overall survival (OS) rates were calculated using the Kaplan–Meier method and were compared between subgroups using the log rank test. Toxicity was classified using common terminology criteria of adverse events version 5.0. Eighteen patients with inoperable MSC with neck lymph node metastasis including 12 men and 6 women with a median age of 67 years were analyzed. The histologic diagnoses were as follows: 16 patients had squamous cell carcinomas and 2 had other histology. Four patients had stage T3 MSC, 6 had T4a and 8 had T4b. Among 18 patients, 7 received concurrent systemic chemotherapy and 11 received selective arterial chemo-infusion. The median follow-up period was 17 months. The 2-year LC, PFS and OS rates for the entire cohort were 34, 31 and 46%, respectively. No significant differences were observed for LC, PFS and OS rates between systemic chemotherapy and selective arterial chemo-infusion cohorts. Grade 3 or higher acute toxicity, including both non-hematological and hematological, was observed in nine patients (50%), while no grade 3 or higher late toxicity was observed. In conclusion, we described the results of definitive RT for MSCs with neck lymph node metastasis. Local recurrence of primary tumor was a frequent pattern of failure and it should be addressed in future study.  相似文献   
54.
This study aimed to research the post-treatment quality of life (QOL) between radiotherapy (RT)- and operation (OP)-treated early cervical cancer survivors, using separate questionnaires for physicians and patients. We administered an observational questionnaire to patients aged 20–70 years old with Stages IB1–IIB cervical cancer who had undergone RT or OP and without recurrence as outpatients for ≥6 months after treatment. We divided 100 registered patients equally into two treatment groups (n = 50 each). The average age was 53 and 44 years in the RT and OP groups, respectively. The RT group included 34 and 66% Stage I and II patients, respectively, whereas the OP group included 66 and 34% Stage I and II patients, respectively. The OP group included 58% of patients with postoperative RT. Combination chemotherapy was performed in 84 and 48% of patients in the RT and OP groups, respectively. On the physicians’ questionnaire, we observed significant differences in bone marrow suppression (RT) and leg edema (OP). On the patients’ questionnaire, significantly more patients had dysuria and leg edema in the OP group than in the RT group, and severe (Score 4–5) leg edema was significantly higher in the post-operative RT group than in the OP only group. The frequency of sexual intercourse decreased after treatment in both groups. On the patients’ questionnaire, there were no significant differences between the two groups regarding sexual activity. These findings are useful to patients and physicians for shared decision-making in treatment choices. The guidance of everyday life and health information including sexual life after treatment is important.  相似文献   
55.
Finger arterial blood pressures determined by a newly developed sphygmomanometer, HEM-802F, were compared with arterial pressure obtained from direct measurement of the radial artery. An excellent correlation was found between the two methods (systolic: r = 0.93, diastolic: r = 0.91), although there was a large variability among individual subjects. The range of differences between them are from +32 to –13mmHg for systolic and +15 to –25mmHg for diastolic blood pressure measurement. HEM-802F underestimated systolic pressure (–4.0mmHg) and overestimated diastolic pressure (+6.7mmHg), compared with intra-arterial readings.The HEM-802F was useful for the non-invasive arterial pressure monitoring during general anesthesia.(Shigemi K, Takahashi H, Hashimoto S et al.: A comparative study of measurement of arterial blood pressure using HEM-802F and arterial cannulation. J Anesth 4: 91–93, 1990)  相似文献   
56.
Immunostaining of the proliferating cell nuclear antigen (PCNA) provides important information about cell kinetics and is easily performed on routinely obtained formalin-fixed, paraffin-embedded materials. We report herein the results of a retrospective study on PCNA staining in esophageal cancer undertaken to determine its significance. As this study indicated that immunoreactivity was preserved in specimens fixed within 24 h, only 31 specimens from surgical patients were available for this investigation. The mean PCNA index of the patients without invasion to the adventitia (35.7±17.9) was significantly lower than that of those with invasion to the adventitia or neighboring structures (49.7±14.5), while the PCNA index did not correlate with other clinicopathologic parameters such as histologic type, lymph node metastases, or prognosis. However, when an analysis of PCNA staining was combined with an analysis of argyrophilic nucleolar organizer region (AgNOR) staining, a correlation with prognosis was found. In fact, seven patients with a high PCNA index (44) and AgNOR count (6) had a significantly poorer prognosis than the remaining 22 (P=0.0014), and six of these seven patients died within 2 years. These results indicate that this combined evaluation may be useful for the identification of patients with a poor prognosis among those undergoing surgery for esophageal squamous cell carcinoma.  相似文献   
57.
Orthograde fast axonal and nonaxonal transport through the optic disc was studied quantitatively and autoradiographically in albino rabbits during elevated (30 or 50 mmHg), normal (13–15 mmHg) and decreased (0–4 mmHg) intraocular pressure (IOP). In cases of intraocular hypertension up to 50 mmHg, autoradiographic findings of a disturbed orthograde fast axonal transport were seen in the optic disc within 3 hr. The blockage was relatively mild and uniform, and was distributed adjacent to the extension line of sclera. Despite this histological evidence of blockage, a quantitative analysis showed no statistically significant decrease in axonally transferred radioactivity within 3 hr. Decrease in the transferred material was evident at 6 hr, and the extent of decrease was mild (ca. 20% at the most prominent portion). In cases of moderate intraocular hypertension (30 mmHg) for 6 hr, a quantitative analysis showed no decrease in axonal transport. After 3–6 hr of intraocular hypotension (0–4 mmHg), papilledema did not develop and autoradiographically there was no accumulatjon of axonal components. Axonally transferred material remained quantitatively at the same level as in the control animals. Nonaxonal transport along the optic nerve was doubly enhanced in cases of intraocular hypertension up to 50 mmHg, and was reduced to one thrid at level of 0–4 mmHg. Filtration of intraocular fluid through the optic disc appears to be the largest component of the nonoxonal transport.  相似文献   
58.
E Chihara  Y Honda 《Ophthalmology》1992,99(2):208-214
The authors evaluated the correlation between various parameters and the local preservation of the retinal nerve fiber layer in 156 glaucomatous eyes. A vessel-associated preservation of the nerve fiber layer was observed in 45 of the 156 glaucomatous eyes. The presence of "straight" retinal vessels (either arterioles or large venules) and "tortuous" retinal vessels (large or small venules) inside of the scleral ring was correlated with the local preservation of the nerve fiber layer (P less than 0.001 and P less than 0.05, respectively). A local elevation of the floor of the cup was also correlated with the preservation of the nerve fiber layer (P less than 0.01). However, no correlation existed between either the preservation of the nerve fiber layer and the type of glaucoma, sex or age of patient, tilting of the disc, cilioretinal vessel, vertical cup-to-disc ratio, refractive error, disc size, distance between the disc and foveola, or the index of ovalness of the disc. These results suggest that retinal vessels in the disc significantly influence the vulnerability of the nerve fibers to glaucomatous damage.  相似文献   
59.
Three patients with herpes zoster ophthalmicus were treated with an oral administration of colchicine and corticosteroid, while another seven were given systemic corticosteroid, vitamins, and sedatives. Colchicine inhibited the formation of new skin lesions but did not suppress the already grown vesicles. The effect of colchicine was attributed to a blockage of intra-axonal dissemination by neurotrophic virus.  相似文献   
60.
PURPOSE: The aim of this report was to indicate both the advantages and disadvantages of local cell transfer therapy using ex vivo expanded autologous tumor-specific T lymphocytes (ATTLs) for recurrent cases of malignant gliomas. EXPERIMENTAL DESIGN: Subjects are 10 cases of malignant gliomas consisting of 7 cases of glioblastoma multiforme, 2 cases of anaplastic astrocytoma, and 1 case of anaplastic oligoastrocytoma. All cases were recurrences. ATTLs were induced by coculturing peripheral blood mononuclear cells with autologous tumor cells in medium containing interleukin-1, -2, -4, and -6 and administered into the local tumor site in total numbers of 3-247 x 10(7) cells. As end points, tumor response and survival time were analyzed observing clinical state. RESULTS: Five cases responded to this therapy (namely, one case showed complete remission, and four cases had a partial response). There were three cases of no change, and two cases of progressive disease. The overall tumor response rate was 50%. No complications were noticed, except for two cases of minor local hemorrhage and eight cases of temporary fever. Nine cases died of further tumor progression, and one case died of aspiration pneumonia, and the cause-specific survival analysis indicates that the median survival time was 5 months from the initial ATTL injection. CONCLUSIONS: The results suggest that local administration of ATTLs is effective in recurrent malignant gliomas in that it demonstrated a high benefit:risk ratio with minor side effects. Although its antitumor effect may be temporary in some advanced cases, it is highly possible that the tumor could be stabilized when conditions are optimal.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号