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   15827篇
  免费   1195篇
  国内免费   371篇
耳鼻咽喉   140篇
儿科学   352篇
妇产科学   313篇
基础医学   1483篇
口腔科学   233篇
临床医学   1343篇
内科学   2214篇
皮肤病学   302篇
神经病学   672篇
特种医学   858篇
外国民族医学   8篇
外科学   3413篇
综合类   1814篇
一般理论   1篇
预防医学   484篇
眼科学   118篇
药学   1187篇
  11篇
中国医学   659篇
肿瘤学   1788篇
  2024年   11篇
  2023年   266篇
  2022年   391篇
  2021年   635篇
  2020年   690篇
  2019年   588篇
  2018年   619篇
  2017年   541篇
  2016年   595篇
  2015年   525篇
  2014年   982篇
  2013年   997篇
  2012年   767篇
  2011年   891篇
  2010年   775篇
  2009年   801篇
  2008年   796篇
  2007年   789篇
  2006年   667篇
  2005年   662篇
  2004年   577篇
  2003年   469篇
  2002年   383篇
  2001年   327篇
  2000年   239篇
  1999年   228篇
  1998年   224篇
  1997年   170篇
  1996年   188篇
  1995年   176篇
  1994年   162篇
  1993年   142篇
  1992年   125篇
  1991年   119篇
  1990年   109篇
  1989年   94篇
  1988年   81篇
  1987年   61篇
  1986年   57篇
  1985年   88篇
  1984年   59篇
  1983年   39篇
  1982年   52篇
  1981年   49篇
  1980年   43篇
  1979年   35篇
  1978年   29篇
  1977年   29篇
  1976年   14篇
  1975年   8篇
排序方式: 共有10000条查询结果,搜索用时 16 毫秒
1.
目的分析超声引导下经皮肺穿刺活检术术后并发症的相关影响因素。 方法收集2015年1月至2017年12月于西部战区总医院住院并在超声引导下行经皮肺穿刺活检术的205例患者临床资料,分析205例患者穿刺术后病理结果及并发症发生率,探讨超声引导下经皮肺穿刺活检术术后并发症的相关影响因素。 结果205例患者行超声引导下经皮肺穿刺活检术,术后并发出血8例,占3.9%(8/205),术后发热3例,占1.46% (3/205),为低热,且予以对症治疗后均恢复正常,无严重并发症发生。术后出血的发生率在不同性别、年龄、BMI及病灶类型的患者中无显著差异(P>0.05),且吸烟对患者术后出血率也无显著影响(P>0.05);但有基础疾病的患者其术后出血率更高(P=0.005),且病灶直径越小,术后越容易并发出血(P=0.006)。不同性别、年龄及病灶类型对术后发热的发生率无显著影响(P>0.05),且术后发热与吸烟史及基础疾病史无关(P>0.05),但BMI≥24或3 cm ≤病灶直径(d)<6 cm的患者术后更易发热(P<0.05)。 结论超声引导下经皮肺穿刺活检术术后并发症发生率低(约为5.37%),主要为出血及低热,其中术后出血主要与基础疾病史和病灶直径有关,术后发热主要与病灶直径及BMI有关。  相似文献   
2.
《Cirugía espa?ola》2023,101(5):325-332
IntroductionIn our institution, the study of selective sentinel node biopsy (SLNB) is performed intraoperatively. The main objective of our study is to know the proportion of patients who benefits from the waiting of the results of SLNB.MethodsA retrospective analysis of patients operated on our center between January 1 st, 2018 and June 30, 2019 was carried out. We included women diagnosed with T1–T2 tumors, treated by lumpectomy and SLNB studied using OSNA method.ResultsOur study included 149 women. There were not statistically significant differences in terms of demographic data between the group treated with axillary lymph node dissection (ALND) and exclusively SLNB group. After analysis of SLN intraoperatively, there were performed 18 axillary lymphadenectomies. Only in six of these 18 cases, three or more sentinel nodes were founded. The location of the tumor, the presence of lymphovascular permeation and the total tumor load (TTL) showed statistically significant differences between groups. Only the TTL was established as the independent factor of the need for ALND.ConclusionsObtaining a deferred result of the SLNB allowed reducing the time of anesthesia and occupation of the operating room, since in a high percentage of cases an additional procedure is not performed.  相似文献   
3.
4.
5.
Breast core biopsies are a standard component of the triple approach that includes clinical examination, imaging and tissue sampling. Conventional cores, diagnostic vacuum assisted biopsy and vacuum assisted excisions are established methods for sampling and managing breast lesions. It is important to be aware of the potential pitfalls in the technical handling and interpretation of the limited core biopsy samples. Here, we present a clinically oriented, well illustrated overview of the common diagnostic pitfalls based on the author's diagnostic and second opinion practice, emphasize the value of clinicopathological correlation and provide histological tips and clues with useful immunohistochemistry to aid the reporting pathologists in their daily interpretation of breast core biopsies.  相似文献   
6.
Patients undergoing sentinel node biopsy (SLNB) for early oral squamous cell carcinoma (OSCC) who harbour occult metastases (pN+ve) may be at greater risk of mortality due to prolonged overall treatment times than those identified as pN+ve on elective neck dissection (ELND). A retrospective comparative survival analysis was therefore undertaken to test this hypothesis. Patients were identified from the South Glasgow multidisciplinary team (MDT) database. Group 1 comprised 38 patients identified as pN+ve, or who were false negative, on sentinel lymph node biopsy (SLNB). Group 2 comprised 146 patients staged pN+ve on ELND. The groups were compared with the Kaplan Meier method and Cox proportional hazards model. In addition, a matched-pair analysis was performed. A unique and specifically designed algorithm was deployed to optimise the pairings. No difference in disease-specific or overall survival was found between the groups. Patients undergoing SLNB as the initial neck staging modality in early OSCC and are identified as pN+ve do not appear to be at a survival disadvantage compared with those staged with ELND.  相似文献   
7.
8.
In the field of drug development, technology for producing human metabolites at a low cost is required. In this study, we explored the possibility of using prokaryotic water-soluble cytochrome P450 (CYP) to produce human metabolites. Streptomyces griseolus CYP105A1 metabolizes various non-steroidal anti-inflammatory drugs (NSAIDs), including diclofenac, mefenamic acid, flufenamic acid, tolfenamic acid, meclofenamic acid, and ibuprofen. CYP105A1 showed 4′-hydroxylation activity towards diclofenac, mefenamic acid, flufenamic acid, tolfenamic acid, and meclofenamic acid. It should be noted that this reaction specificity was similar to that of human CYP2C9. In the case of mefenamic acid, another metabolite, 3′-hydroxymethyl mefenamic acid, was detected as a major metabolite. Substitution of Arg at position 73 with Ala in CYP105A1 dramatically reduced the hydroxylation activity toward diclofenac, flufenamic acid, and ibuprofen, indicating that Arg73 is essential for the hydroxylation of these substrates. In contrast, substitution of Arg84 with Ala remarkably increased the hydroxylation activity towards diclofenac, mefenamic acid, and flufenamic acid. Recombinant Rhodococcus erythrocyte cells expressing the CYP105A1 variant R84A/M239A showed complete conversion of diclofenac into 4′-hydroxydiclofenac. These results suggest the usefulness of recombinant R. erythropolis cells expressing actinomycete CYP, such as CYP105A1, for the production of human drug metabolites.  相似文献   
9.
In forensic medicine, although various alcohols have been reported as indicators of decomposition in collected blood, no studies have examined short-chain fatty acids as indicators. In this study, the blood n-butyric acid concentration was quantified, and the association between n-butyric acid and decomposition was investigated to determine whether the detection of n-butyric acid could be a new indicator of decomposition. Among the forensic autopsies performed from 2016 to 2018 in our laboratory, the cases were divided into decomposed (n = 20) and non-decomposed (n = 20) groups based on macroscopic findings. Blood samples collected at the time of autopsy were derivatized with 3-nitrophenylhydrazine hydrochloride after solid-phase extraction. The n-butyric acid concentration was measured using liquid chromatography–tandem mass spectrometry. In addition, ethanol and n-propanol were measured using a gas chromatography-flame ionization detector. There was a significant difference (p < 0.01) in the concentrations of n-butyric acid between the decomposed and non-decomposed groups (0.343 ± 0.259 [0.030–0.973] and 0.003 ± 0.002 [0.001–0.007] mg/mL, respectively). In the decomposed group, n-butyric acid was detected at high concentrations, even in cases where n-propanol was low. These results suggest that n-butyric acid is more likely to be an indicator of blood decomposition than n-propanol.  相似文献   
10.
BackgroundIn order to avoid excessive treatment of thyroid nodules in the clinic, it is necessary to find a simple and practical analysis method to comprehensively and accurately reflect benign or malignant thyroid nodules. This study aimed to construct and validate a comprehensive and reliable network-based predictive model using a variety of imaging and laboratory criteria for thyroid nodules to stratify the risk of malignancy prior to surgery.MethodsWe retrospectively analyzed data from patients who underwent surgical treatment for thyroid nodules at the Thyroid and Breast Diagnosis and Treatment Center of Weifang Hospital of Traditional Chinese Medicine between January 2018 and December 2020. Binary logical regression analysis was performed to predict whether nodules were malignant or benign. The developmental dataset included 457 patients (January 2018–December 2020). The validation set included separate data points (n = 225, January 2018–December 2020).ResultsIn this study, criteria that showed significant predictive value for malignant nodules included TI-RADS: 4b (p = 0.065); Bethesda IV, Bethesda V, Bethesda VI (P < 0.0001); BRAFV600E mutation (P < 0.0001); Calcitonin>5 pg/ml (p = 0.0037); and FNA-Tg>30 ng/ml (p = 0.0003). A 10-grade risk scoring system was developed. The risk of malignancy risk ranged from 2.06% to 100% and was positively associated with increasing risk grade. The areas under the receiver-operating characteristic curve of the development and validation sets were 0.972 and 0.946, respectively.ConclusionA simple, comprehensive and reliable web-based predictive model was designed using a variety of imaging and laboratory criteria to stratify thyroid nodules by probability of malignancy.  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