全文获取类型
收费全文 | 6253篇 |
免费 | 273篇 |
国内免费 | 107篇 |
专业分类
耳鼻咽喉 | 72篇 |
儿科学 | 74篇 |
妇产科学 | 132篇 |
基础医学 | 819篇 |
口腔科学 | 89篇 |
临床医学 | 501篇 |
内科学 | 1395篇 |
皮肤病学 | 94篇 |
神经病学 | 451篇 |
特种医学 | 474篇 |
外科学 | 852篇 |
综合类 | 32篇 |
预防医学 | 180篇 |
眼科学 | 63篇 |
药学 | 680篇 |
中国医学 | 93篇 |
肿瘤学 | 632篇 |
出版年
2023年 | 44篇 |
2022年 | 143篇 |
2021年 | 213篇 |
2020年 | 101篇 |
2019年 | 146篇 |
2018年 | 159篇 |
2017年 | 137篇 |
2016年 | 191篇 |
2015年 | 255篇 |
2014年 | 284篇 |
2013年 | 340篇 |
2012年 | 522篇 |
2011年 | 514篇 |
2010年 | 351篇 |
2009年 | 235篇 |
2008年 | 395篇 |
2007年 | 372篇 |
2006年 | 317篇 |
2005年 | 297篇 |
2004年 | 246篇 |
2003年 | 203篇 |
2002年 | 160篇 |
2001年 | 140篇 |
2000年 | 145篇 |
1999年 | 112篇 |
1998年 | 67篇 |
1997年 | 48篇 |
1996年 | 41篇 |
1995年 | 33篇 |
1994年 | 27篇 |
1993年 | 21篇 |
1992年 | 31篇 |
1991年 | 34篇 |
1990年 | 33篇 |
1989年 | 37篇 |
1988年 | 31篇 |
1987年 | 32篇 |
1986年 | 16篇 |
1985年 | 22篇 |
1984年 | 16篇 |
1983年 | 13篇 |
1982年 | 16篇 |
1981年 | 9篇 |
1980年 | 9篇 |
1979年 | 9篇 |
1976年 | 7篇 |
1973年 | 7篇 |
1971年 | 7篇 |
1969年 | 7篇 |
1968年 | 6篇 |
排序方式: 共有6633条查询结果,搜索用时 12 毫秒
51.
BACKGROUND: The carina level has been shown to be near the pericardial reflectionand can easily be identified as a landmark on a routine chestradiography. The purpose of this study was to reveal a simplemethod to predict the adequate central venous catheter (CVC)depth, hereby facilitating safe positioning of the CVC tip. METHODS: Central venous catheterization was performed via the right internaljugular vein (IJV) or the right subclavian vein (SCV). The CVCwas placed at a depth derived by adding the length between theneedle insertion point and the clavicular notch and the verticallength between the clavicular notch and the carina on the chestradiograph. The distance between the CVC tip and the carinawas measured on the postoperative chest radiograph. RESULTS: The tip position of 100 CVCs placed via the right IJV was 0.1(1.1) cm [mean (SD)] below the carina (95% CI: 0.3 cm belowcarina0.2 cm above carina) and the tip positionof 153 CVCs placed via the right SCV was 0.0 (1.2) cm [mean(SD)] below the carina (95% CI: 0.2 cm below carina0.2 cmabove carina). There were nine outliers (two in IJV group andseven in SCV group). CONCLUSIONS: When CVCs are inserted to a depth derived by adding the lengthbetween the needle insertion point and the clavicular notchand the vertical length between the clavicular notch and thecarina, the CVC tip can be reliably placed near the carina level. 相似文献
52.
Yoo TH Li JJ Kim JJ Jung DS Kwak SJ Ryu DR Choi HY Kim JS Kim HJ Han SH Lee JE Han DS Kang SW 《Kidney international》2007,71(10):1019-1027
The autocrine and paracrine activation of the renin-angiotensin system (RAS) within cells of the kidney plays a role in the overall pathophysiology of the renal disease due to diabetes. In this study, we focus on components of the RAS in the podocyte as these cells are important in the pathogenesis of glomerulosclerosis and proteinuria. Immortalized mouse podocytes were exposed to media containing normal glucose (NG) or high glucose (HG) for in vitro studies. In vivo studies utilized kidney tissue obtained from rats treated for 3 months with streptozotocin to induce diabetes. Angiotensinogen (AGT) and the angiotensin II (AII) type 1 receptor mRNA and protein were significantly increased in the podocytes cultured under the high glucose conditions. Both angiotensins I and II levels were significantly higher in cell lysates and the conditioned media of cells grown in high glucose. There were no differences in renin activity, angiotensin-converting enzyme level, or AII type 2 receptor level. Glomerular AGT and AII type 1 receptor assessed by means of immunohistochemistry were increased in diabetic rats compared with the control rats. Other measured components of the RAS within the glomeruli were not different. We suggest that increased AGT, an attendant increase in AII and increased AII type 1 receptor in podocytes experiencing diabetic conditions play an important role in the pathogenesis of diabetic nephropathy. 相似文献
53.
Keung Nyun Kim Poong Gee Ahn Mi Jung Ryu Dong Ah Shin Seong Yi Do Heum Yoon Yoon Ha 《European spine journal》2014,23(7):1464-1471
Purpose
To understand the long-term surgical outcomes and prognostic factors for the operative treatment of cervical myelopathy (CM) in patients with athetoid cerebral palsy (ACP).Methods
We retrospectively reviewed 24 patients with ACP who underwent surgery for CM at our hospital between March 2002 and June 2008. All patients had more than 5 years follow-up. Anterior fusion (11 patients), posterior fusion (1 patient), or combined anterior and posterior (AP) fusion (7 patients) and C1-2 fusion (5 patients) surgeries were performed. Surgical outcomes (average follow-up 102 months), as assessed using modified JOA (mJOA) scores, the Neck Disability Index (NDI), and a visual analog scale (VAS) were compared between the preoperative and postoperative states.Results
Preoperatvie cervical kyphosis decreased mJOA scores significantly. Long-term follow-up clinical outcomes demonstrated that 10 patients showed favorable (excellent and good) outcomes and 11 patients had non-favorable (fair and worse) outcomes. According to the mJOA scores, patients showed postoperative improvement (7.10–10.45). NDI decreased from 68.46 to 31.66. A second operation was done in seven cases due to instrument failure, progressive kyphotic deformities and adjacent segment degeneration. A preoperative botulinum toxin injection significantly decreased (p < 0.05) the incidence of a second operation.Conclusions
Patients with ACP have high incidence of instrument failure. Strong surgical fixation, bone fusion and perioperative immobilizations using botulinum toxin injection should be carefully planned preoperatively. 相似文献54.
A Body Shape Index Has a Good Correlation with Postoperative Complications in Gastric Cancer Surgery
Bang Wool Eom MD Jungnam Joo PhD Hong Man Yoon MD Keun Won Ryu MD PhD Young-Woo Kim MD PhD Jun Ho Lee MD PhD 《Annals of surgical oncology》2014,21(4):1115-1122
Background
The relationship between obesity and surgical complications has been controversial. A Body Shape Index (ABSI) is a newly developed anthropometric index based on waist circumference adjusted for height and weight. The aim of this study was to investigate the relationship between ABSI and surgical complications.Methods
From November 2001 to September 2012, 4,813 patients underwent curative resection for gastric cancer. ABSI was defined as waist circumference divided by (BMI2/3height1/2). Data of clinicopathologic characteristics and morbidity were collected by retrospective review. Binary logistic regression was used for multivariable analyses to determine whether ABSI was independently associated with postoperative complications.Results
The incidence of overall surgical complications was 13.4 %, and the most common complication was ileus (2.8 %). In the multivariable analysis, ABSI was an independent factor for overall complications [odds ratio (OR), 1.22; 95 % confidence interval (CI) 1.01–1.48; P = 0.041). However, BMI showed no statistical significance (OR, 1.03; 95 % CI 1.00–1.06; P = 0.063). In the subgroup analyses, ABSI was significantly associated with overall complications regarding open gastrectomy (OR, 1.26; 95 % CI 1.01–1.57; P = 0.039). Regarding laparoscopy-assisted gastrectomy, ABSI had no significant effect on overall complications (P = 0.844).Conclusions
ABSI shows good correlation with surgical complications in patients with gastric cancer. Further studies are needed for the various clinical roles of ABSI, and the results could be helpful to determine the effect of abdominal obesity on gastric cancer surgery and the clinical usefulness of ABSI. 相似文献55.
Ji Yeon Park MD Keun Won Ryu MD PhD Bang Wool Eom MD Hong Man Yoon MD Soo Jin Kim MD Soo-Jeong Cho MD PhD Jong Yeul Lee MD Chan Gyoo Kim MD PhD Myeong-Cherl Kook MD PhD Il Ju Choi MD PhD Byung Ho Nam PhD Young-Woo Kim MD PhD 《Annals of surgical oncology》2014,21(4):1123-1129
Background
There is no consensus on the optimal method of primary tumor control, determined by preoperative clinical factors, during sentinel node (SN) navigation surgery for early gastric cancer (EGC). In this study, we investigated the accuracy of clinical diagnosis based on preoperative examination in patients with EGC and proposed surgical options for primary tumor control during SN navigation surgery.Methods
We analyzed 815 patients with clinical stage IA gastric cancer who underwent gastrectomy at the National Cancer Center in Korea between March 2001 and February 2011. The clinical stage was determined by endoscopy, endoscopic ultrasonography, and abdominal computed tomography.Results
The preoperative assessment of tumor depth and tumor size was accurate in 57.5 and 70.8 % of patients, respectively. Tumor depth and size were underestimated in 8 and 25.3 % of patients. The overall accuracy of histologic diagnosis by endoscopic biopsy was 87.2 %. Of those tumors diagnosed preoperatively as differentiated, 20.5 % revealed mixed histology of undifferentiated type.Conclusions
The recommendation for SN biopsy may be limited to tumors sized 3 cm or smaller to avoid positive lateral margins and to minimize the risk of skip metastases. Endoscopic resection may safely be applied to small mucosal cancers, but other surgical options should be employed for undifferentiated large mucosal lesions, given their tendency for diffuse invasion. Full-thickness resection is preferable for submucosal cancers, to secure clear vertical margins. 相似文献56.
Jung-Woo Woo Keun Won Ryu Ji Yeon Park Bang Wool Eom Mi Jung Kim Hong Man Yoon Sook Ryun Park Myeong-Cherl Kook Il Ju Choi Young-Woo Kim Young-Iee Park 《World journal of surgery》2014,38(2):439-446
Background
The prognosis of patients with positive surgical resection margins is dismal in gastric cancer. However, the influence of positive margin itself on prognosis is still uncertain, especially in advanced gastric cancer (AGC). The aims of the present study were to evaluate the prognostic impact of microscopic tumor involved resection margins in stage III–IV AGC after gastric resection in comparison with other well-known factors.Methods
Among 1,536 consecutive gastric cancer patients who received intentional curative resection for stage III–IV AGC between April 2001 and December 2011 at the National Cancer Center, 35 patients (2.28 %) had positive resection margins on their final histology. A comparison of clinicopathologic characteristics, recurrence pattern, overall survival (OS), and disease-free survival (DFS) was made between positive margin (PM) patients and negative margin (NM) patients.Results
Among the 35 PM patients, 15 (42.9 %) had proximal involved margins, 21 (60.0 %) had distal involved margins, and one (2.9 %) had both involved margins. Twenty-eight PM patients (80.0 %) were stage III, and 7 (20.0 %) were stage IV. Recurrence was significantly higher in PM than NM (63.6 % vs. 39.7 %, respectively; p = 0.005). The OS and DFS rates were significantly lower in the PM group than in the NM group (14.9 vs. 36.3 months, p < 0.001 and 11.6 vs. 27.1 months, p = 0.005, respectively). The presence of PM was an independent risk factor for both OS and DFS.Conclusions
The presence of PM is an independent risk factor for OS and DFS. Considering the prognostic impact of PM, a sufficient resection margin should be ensured when determining the resection line in gastrectomy with curative intent. The reoperation to secure clear resection margins should be considered as a treatment of choice in the case of PM. 相似文献57.
58.
Prospective evaluation of thoracic pedicle screw placement using fluoroscopic imaging 总被引:6,自引:0,他引:6
BACKGROUND: In this prospective 18-month study, 29 patients underwent posterior thoracic instrumentation with placement of 209 transpedicular screws guided by intraoperative fluoroscopic imaging and anatomic landmarks. We assessed the safety, accuracy, complications, and early stability of this technique. METHODS: Pedicle and pedicle-rib units were measured, and screw cortical penetrations were graded on anatomy and depth of penetration. All 29 patients underwent preoperative computed tomographic (CT) imaging, and 28 underwent postoperative CT imaging (199/209 screws). RESULTS: From T2 to T12, screw diameters were >or=5 mm with mean medial screw angulation measuring 20-25 degree. Of the 209 screws placed from T1 to T12, 111 had diameters greater than or equal to the pedicle width. From T3 to T9, the mean diameter of the pedicle screws exceeded the mean pedicle width. Lateral pedicle wall penetration occurred significantly more often than superior, inferior, and medial pedicle wall penetrations and anterolateral vertebral body penetration. Five of six high-risk screw penetrations occurred in one patient when intraoperative technique was compromised. We observed no new postoperative neurologic deficits, visceral injuries, or pedicle screw instrumentation failures. The three high-risk anterolateral vertebral body penetrations at T1 and T2 were associated with a significantly decreased mean screw transverse angle; the three high-risk medial pedicle wall penetrations occurring from T3 to T9 were associated with a significantly increased mean screw transverse angle. Among all 26 patients available at postoperative follow-up (mean 11.9 months), the mean loss of kyphosis correction was 2.0 degree. CONCLUSIONS: Guided by intraoperative fluoroscopic imaging and anatomic landmarks, thoracic pedicle screws can be placed safely. Early clinical follow-up reveals excellent results with minimal loss of kyphosis correction. 相似文献
59.
Air-trapping zone surrounding sclerosing hemangioma of the lung 总被引:17,自引:0,他引:17
Nam JE Ryu YH Cho SH Lee YJ Kim HJ Lee DY Choe KO Kim SJ 《Journal of computer assisted tomography》2002,26(3):358-361
We present two cases of sclerosing hemangioma of the lung with a peculiar radiologic finding: an air-trapping zone surrounding the tumor. On microscopic examinations, the tumor was of the hemangiomatous subtype, and the radiolucent zone corresponded to enlarged alveoli with septal destruction. A possible mechanism in the production of an air-trapping zone around a sclerosing hemangioma is bleeding from the highly vascular tumor followed by expectoration in communication with an airway. We reviewed the literature on the air meniscus sign in sclerosing hemangioma and concluded that although it is not a common finding, it could be of help in the confident diagnosis of sclerosing hemangioma and in differentiating it from other benign tumors of the lung. 相似文献
60.
Sung-Jae Kim M.D. In-Seop Park M.D. Yong-Min Cheon M.D. Sang-Wook Ryu M.D. 《Arthroscopy》2004,20(10):481-1094
Recently, attention has been given to the double-bundle technique for treating the posterior cruciate ligament (PCL)-deficient knee. We present an arthroscopic PCL reconstruction using a double-bundle technique with 3-stranded tibialis posterior (TP) allograft that has not been described before. The anterolateral bundle of the PCL is reconstructed using 2-stranded TP allograft and the posteromedial bundle using 1-stranded TP allograft. Three-stranded TP allograft will be an alternative graft choice for PCL reconstruction. 相似文献