全文获取类型
收费全文 | 27261篇 |
免费 | 2262篇 |
国内免费 | 866篇 |
专业分类
耳鼻咽喉 | 210篇 |
儿科学 | 100篇 |
妇产科学 | 2069篇 |
基础医学 | 2684篇 |
口腔科学 | 201篇 |
临床医学 | 2141篇 |
内科学 | 1903篇 |
皮肤病学 | 176篇 |
神经病学 | 647篇 |
特种医学 | 1158篇 |
外国民族医学 | 19篇 |
外科学 | 4523篇 |
综合类 | 4429篇 |
现状与发展 | 2篇 |
预防医学 | 1910篇 |
眼科学 | 44篇 |
药学 | 1702篇 |
9篇 | |
中国医学 | 1228篇 |
肿瘤学 | 5234篇 |
出版年
2024年 | 88篇 |
2023年 | 399篇 |
2022年 | 1024篇 |
2021年 | 1310篇 |
2020年 | 1042篇 |
2019年 | 880篇 |
2018年 | 942篇 |
2017年 | 1001篇 |
2016年 | 1185篇 |
2015年 | 1141篇 |
2014年 | 2246篇 |
2013年 | 1916篇 |
2012年 | 1871篇 |
2011年 | 2012篇 |
2010年 | 1681篇 |
2009年 | 1481篇 |
2008年 | 1307篇 |
2007年 | 1354篇 |
2006年 | 1156篇 |
2005年 | 978篇 |
2004年 | 781篇 |
2003年 | 675篇 |
2002年 | 532篇 |
2001年 | 455篇 |
2000年 | 401篇 |
1999年 | 328篇 |
1998年 | 294篇 |
1997年 | 251篇 |
1996年 | 209篇 |
1995年 | 223篇 |
1994年 | 169篇 |
1993年 | 165篇 |
1992年 | 116篇 |
1991年 | 119篇 |
1990年 | 72篇 |
1989年 | 78篇 |
1988年 | 66篇 |
1987年 | 64篇 |
1986年 | 48篇 |
1985年 | 60篇 |
1984年 | 62篇 |
1983年 | 40篇 |
1982年 | 29篇 |
1981年 | 31篇 |
1980年 | 25篇 |
1979年 | 28篇 |
1978年 | 18篇 |
1977年 | 13篇 |
1976年 | 11篇 |
1973年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
《Diagnostic and interventional imaging》2020,101(9):555-564
PurposeThe purpose of this study was to determine whether computed tomography (CT)-based machine learning of radiomics features could help distinguish autoimmune pancreatitis (AIP) from pancreatic ductal adenocarcinoma (PDAC).Materials and MethodsEighty-nine patients with AIP (65 men, 24 women; mean age, 59.7 ± 13.9 [SD] years; range: 21–83 years) and 93 patients with PDAC (68 men, 25 women; mean age, 60.1 ± 12.3 [SD] years; range: 36–86 years) were retrospectively included. All patients had dedicated dual-phase pancreatic protocol CT between 2004 and 2018. Thin-slice images (0.75/0.5 mm thickness/increment) were compared with thick-slices images (3 or 5 mm thickness/increment). Pancreatic regions involved by PDAC or AIP (areas of enlargement, altered enhancement, effacement of pancreatic duct) as well as uninvolved parenchyma were segmented as three-dimensional volumes. Four hundred and thirty-one radiomics features were extracted and a random forest was used to distinguish AIP from PDAC. CT data of 60 AIP and 60 PDAC patients were used for training and those of 29 AIP and 33 PDAC independent patients were used for testing.ResultsThe pancreas was diffusely involved in 37 (37/89; 41.6%) patients with AIP and not diffusely in 52 (52/89; 58.4%) patients. Using machine learning, 95.2% (59/62; 95% confidence interval [CI]: 89.8–100%), 83.9% (52:67; 95% CI: 74.7–93.0%) and 77.4% (48/62; 95% CI: 67.0–87.8%) of the 62 test patients were correctly classified as either having PDAC or AIP with thin-slice venous phase, thin-slice arterial phase, and thick-slice venous phase CT, respectively. Three of the 29 patients with AIP (3/29; 10.3%) were incorrectly classified as having PDAC but all 33 patients with PDAC (33/33; 100%) were correctly classified with thin-slice venous phase with 89.7% sensitivity (26/29; 95% CI: 78.6–100%) and 100% specificity (33/33; 95% CI: 93–100%) for the diagnosis of AIP, 95.2% accuracy (59/62; 95% CI: 89.8–100%) and area under the curve of 0.975 (95% CI: 0.936–1.0).ConclusionsRadiomic features help differentiate AIP from PDAC with an overall accuracy of 95.2%. 相似文献
2.
M. Iachina P.M. Ljungdalh R.G. Sørensen L. Kaerlev J. Blaakær O. Trosko N. Qvist B.M. Nørgård 《Clinical oncology (Royal College of Radiologists (Great Britain))》2019,31(2):115-123
Aims
To examine the influence of pre-existing psychiatric disorder on the choice of treatment in patients with gynaecological cancer.Materials and methods
The analyses were based on all patients who underwent surgical treatment for endometrial, ovarian or cervical cancer who were registered in the Danish Gynecological Cancer Database in the years 2007–2014 (3059 patients with ovarian cancer, 5100 patients with endometrial cancer and 1150 with cervical cancer). Logistic regression model and Cox regression model, adjusted for relevant confounders, were used to estimate the effect of pre-existing psychiatric disorder on the course of cancer treatment. Our outcomes were (i) presurgical oncological treatment, (ii) macroradical surgery for patients with ovarian cancer, (iii) radiation/chemotherapy within 30 days and 100 days after surgery and (iv) time from surgery to first oncological treatment.Results
In the group of patients with ovarian cancer, more patients with a psychiatric disorder received macroradical surgery versus patients without a psychiatric disorder, corresponding to an adjusted odds ratio of 1.24 (95% confidence interval 0.62–2.41) and the chance for having oncological treatment within 100 days was odds ratio = 1.26 (95% confidence interval 0.77–2.10). As for patients with endometrial cancer, all outcome estimates were close to unity. The adjusted odds ratio for oncological treatment within 30 days after surgery in patients with cervical cancer with a history of psychiatric disorder was 0.20 (95% confidence interval 0.03–1.54).Conclusions
We did not find any significant differences in the treatment of ovarian and endometrial cancer in patients with pre-existing psychiatric diagnoses. When it comes to oncological treatment, we suggest that increased attention should be paid to patients with cervical cancer having a pre-existing psychiatric diagnosis. 相似文献3.
Distribution patterns of transforaminal injections in the cervical spine evaluated by multi-slice computed tomography 总被引:1,自引:1,他引:0
Transforaminal injections are sometimes used for the diagnosis and treatment of painful conditions in the lumbar and to a lesser degree in the cervical spine. The technique is most often used when investigating/treating radiculopathy caused by degenerative disease. But how selective are the nerve root blocks? What possible structures other than the intended nerve root are affected from such injections? This study was undertaken in order to try to answer these questions, as no study focusing on the possible spread from the transforaminal selective nerve root blocks in the cervical spine has been performed earlier. In three groups of patients, each group including three patients, we injected three different volumes (0.6, 1.1 and 1.7 ml) with a transforaminal technique in the cervical spine. In all the injections, a small amount of contrast media was added. The spread of the injections were then investigated using multi-slice computed tomography with reconstructions. The imaging revealed a possible effect on other nerve roots than the intended ones when a larger volume was used for the root blocks. The spread was related to the injected volume as well as to local anatomy (size of foraminal area). In this study, only 0.6-ml injections could be accepted for being selective enough for diagnostic investigations. 相似文献
4.
5.
颈椎旋转、半失稳在椎动脉型、交感型、神经根型颈椎病间的相关研究 总被引:6,自引:0,他引:6
目的:探讨椎动脉型颈椎病、交感型颈椎病、神经根型颈椎病之间颈椎旋转、半失稳的关系。方法:本组112例,其中椎动脉型38型、交感型36例、神经根型38例,应用图像存档和传输系统(picture archiving and communication systems,PACS)在X线正位片上测量患者每个颈椎椎体的旋转度和在侧位片上测量椎体半失稳的位移距离。结果:在C6旋转度上,椎动脉型颈椎病和交感型颈椎病均与神经根型颈椎病有统计学差异(P<0·01),椎动脉型颈椎病和交感型颈椎病间的C2旋转度有统计学差异(P<0·05),椎动脉型颈椎病和神经根型颈椎病间的C4旋转度有统计学差异(P<0·05)。在椎体半失稳的位移距离和椎体半失稳率上,椎动脉型颈椎病和交感型颈椎病均与神经根型颈椎病有统计学差异(P<0·01)。结论:在椎动脉型颈椎病和交感型颈椎病中椎体半失稳和颈椎旋转是它们发病的一个重要因素,而在神经根型颈椎病中不是发病的重要因素。 相似文献
6.
C.A. AMEZCUA H.R. MACDONALD† C.A. LUM W. YI‡ L.I. MUDERSPACH† L.D. ROMAN† & J.C. FELIX† 《International journal of gynecological cancer》2006,16(3):1336-1341
In this study, we examine the prevalence of finding isolated tumor cells (ITCs) in negative lymph nodes of endometrial cancer patients using immunohistochemistry. Seventy-six endometrial cancer patients with lymph nodes histologically negative for metastatic disease were examined. Nodal tissue sections were stained with anticytokeratin antibodies AE-1 and CAM 5.2. Nodes with single or groups of cells (two to four cells) < or =0.2 mm and showing cytokeratin reactivity were positive for ITCs. Findings were compared to features of the primary tumor and patient outcome. ITCs were present in 31 of 1712 lymph nodes. Fifteen (19.7%) patients had ITC-positive nodes. ITCs involved only pelvic nodes in nine cases, only para-aortic nodes in five cases, and pelvic and para-aortic in one case. Tumor in adnexa was the only pathologic feature associated with nodal ITCs (P= 0.0485). All 15 patients with nodal ITCs were alive at follow-up. One (6.7%) patient suffered recurrent disease but was alive at last encounter. Disease recurred in 5 (8.8%) of 57 patients without nodal ITCs. Two are alive without disease, two alive with disease, and one died from her cancer. In summary, a significant proportion of endometrial cancer patients have ITCs detected by immunohistochemistry in histologically negative regional lymph nodes. 相似文献
7.
烹调油烟致大小鼠肺癌的实验研究 总被引:1,自引:0,他引:1
[目的]了解烹调油烟(cooking oil fumes,COF)的动物致癌性。[方法]采用动式染毒法给Balb/c小鼠(雌雄各半)吸入COF浓度为9.09、20.65、38.85mg/m^3,染毒1次/1~2d,30min/次,共150次,计8个月;SD大鼠(雌雄各半)吸入COF浓度为6、88、15.06、35.33mg/m^3,染毒1次/2d,30min/次,共191次,计12.5个月。分别制备COF慢性中毒动物模型;两实验均设空白对照组,吸入与实验组相同温度的清洁空气。[结果]COF诱发Balb/c小鼠实验组肺癌总发生率为18、95%(29/153),低、中、高浓度组肺癌发生率分别为15.09%、20、00%和22.00%,与对照组差异均有显著性。但低、中、高三组间差异无显著性(P〉0.05);COF诱发SD大鼠肺癌总发生率为9、10%(9/99),低、中、高浓度组肺癌发生率分别为6.45%、8.57%、12.12%,高浓度组肺癌发生率高于对照组(P〈0.05)。各性别组间肺癌发生率的差别无显著性(P〉0.05)。[结论]COF可以诱导Balb/c小鼠和SD大鼠肺癌,诱发的肺癌主要为肺腺癌(小鼠28/29,大鼠7/9),余为小细胞肺癌。 相似文献
8.
Background contextLarge, prominent osteophytes along the anterior aspect of the cervical spine have been reported as a cause of dysphagia. Improvement of swallowing after surgical resection has been reported in a few case reports with short-term follow-up. The current report describes outcomes of a series of five patients with surgical treatment for this rare disorder, with a long-term follow-up.PurposeTo study the clinical and radiographic outcomes of a case series of patients surgically treated for dysphagia secondary to cervical diffuse idiopathic skeletal hyperostosis (DISH).Study designRetrospective review of a case series.Patient sampleFive cases from a University Hospital.Outcome measuresClinical and imagenological follow-up.MethodsThe records of five patients with dysphagia who had undergone anterior surgical resection of prominent osteophytes secondary to DISH were reviewed. Extrinsic esophageal compression secondary to anterior cervical osteophytes was radiographically confirmed via preoperative barium esophagogram swallowing study. All patients underwent anterior cervical osteophytes resection without fusion. Postoperatively, patients were followed-up clinically and radiographically with routine lateral cervical radiographs.ResultsPreoperative esophagogram showed that the esophageal obstruction was present at one level in three cases and two levels in two cases. The C3–C4 level was involved in three cases, C4–C5 in three cases, and C5–C6 in one case. There were no postoperative complications, including recurrent laryngeal nerve palsy, wound infection, or hematomas. All patients had resolution of dyphagia soon after surgery (within 2 weeks). Postoperative radiographs demonstrated complete removal of osteophytes. At final follow-up, ranging from 1 to 9 years (average 59.8 months, median 53 months), no patients reported recurrence of dysphagia. Final radiographic examination demonstrated minimal regrowth of the osteophytes.ConclusionsAlthough rarely indicated, surgical resection of anterior cervical osteophytes from DISH causing dyphagia produces good clinical and radiographical outcomes. After thorough evaluation to rule out other intrinsic or extrinsic causes of swallowing difficulty, surgical treatment of this uncommon condition might be considered. 相似文献
9.
颈椎病与中医辨证关系的探讨(附100例分析) 总被引:3,自引:0,他引:3
目的:探讨颈椎病与中医分型的辨证关系。方法:对100例该病的影像表现与中医分型进行系统分析。结果:主要临床表现颈部活动受限,颈、肩、背部疼痛,常伴头痛、头晕、视物模糊、耳鸣等症状。风寒型以软组织所致颈曲改变为主。肝肾亏虚型、痰湿交阻型以骨质增生、椎间隙及椎间孔狭窄为主。结论:X线、CT是本病首选检查方法,能与中医辨证有机结合,对中西医治疗有重要意义。 相似文献
10.
Perianal mucinous adenocarcinoma is a rare tumour which may be associated with long‐standing chronic perianal sepsis. Early diagnosis is challenging and is based on a high index of clinical suspicion and specific histological features. Definitive treatment is surgical, in the form of an abdomino‐perineal resection. We hereby describe a case of a perianal mucinous adenocarcinoma arising from long‐standing recurrent perianal fistula and complement this with a brief review of the literature pertaining in particular to the management of this condition. 相似文献