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   6709篇
  免费   324篇
  国内免费   83篇
耳鼻咽喉   18篇
儿科学   162篇
妇产科学   67篇
基础医学   760篇
口腔科学   157篇
临床医学   394篇
内科学   2042篇
皮肤病学   212篇
神经病学   589篇
特种医学   306篇
外科学   1126篇
综合类   25篇
预防医学   168篇
眼科学   52篇
药学   357篇
中国医学   9篇
肿瘤学   672篇
  2023年   44篇
  2022年   82篇
  2021年   134篇
  2020年   93篇
  2019年   130篇
  2018年   142篇
  2017年   98篇
  2016年   130篇
  2015年   103篇
  2014年   165篇
  2013年   193篇
  2012年   309篇
  2011年   377篇
  2010年   239篇
  2009年   192篇
  2008年   365篇
  2007年   409篇
  2006年   407篇
  2005年   435篇
  2004年   439篇
  2003年   468篇
  2002年   469篇
  2001年   134篇
  2000年   144篇
  1999年   130篇
  1998年   115篇
  1997年   84篇
  1996年   67篇
  1995年   68篇
  1994年   58篇
  1993年   60篇
  1992年   76篇
  1991年   95篇
  1990年   75篇
  1989年   71篇
  1988年   60篇
  1987年   51篇
  1986年   47篇
  1985年   42篇
  1984年   32篇
  1983年   33篇
  1982年   17篇
  1981年   18篇
  1980年   16篇
  1979年   17篇
  1978年   23篇
  1975年   18篇
  1973年   15篇
  1971年   16篇
  1970年   17篇
排序方式: 共有7116条查询结果,搜索用时 15 毫秒
91.
Cancer‐associated fibroblasts (CAFs) are reportedly involved in invasion and metastasis in several types of cancer, including gastric cancer (GC), through the stimulation of CXCL12/CXCR4 signaling. However, the mechanisms underlying these tumor‐promoting effects are not well understood, which limits the potential to develop therapeutic targets against CAF‐mediated CXCL12/CXCR4 signaling. CXCL12 expression was analyzed in resected GC tissues from 110 patients by immunohistochemistry (IHC). We established primary cultures of normal fibroblasts (NFs) and CAFs from the GC tissues and examined the functional differences between these primary fibroblasts using co‐culture assays with GC cell lines. We evaluated the efficacy of a CXCR4 antagonist (AMD3100) and a FAK inhibitor (PF‐573,228) on the invasive ability of GC cells. High CXCL12 expression levels were significantly associated with larger tumor size, increased tumor depth, lymphatic invasion and poor prognosis in GC. CXCL12/CXCR4 activation by CAFs mediated integrin β1 clustering at the cell surface and promoted the invasive ability of GC cells. Notably, AMD3100 was more efficient than PF‐573,228 at inhibiting GC cell invasion through the suppression of integrin β1/FAK signaling. These results suggest that CXCL12 derived from CAFs promotes GC cell invasion by enhancing the clustering of integrin β1 in GC cells, resulting in GC progression. Taken together, the inhibition of CXCL12/CXCR4 signaling in GC cells may be a promising therapeutic strategy against GC cell invasion.  相似文献   
92.
A 58-year-old man was diagnosed as having type 3 gastric cancer (poorly differentiated adenocarcinoma). He underwent total gastrectomy with splenectomy, as well as D3 dissection, and received postoperative chemotherapy combining oral uracil and futrafur (UFT) with cisplatin (CDDP), but results showed recurrence of multiple abdominal lymph node metastases around the aorta. He therefore received various anticancer drug regimens (irinotecan [CPT-11]/CDDP; 1 M tegafur-0.4 M gimeracil-1 M oteracil potassium [TS-1], methotrexate (MTX)/5-fluorouracil); however, final results showed growth of lymph node metastasis and simultaneous worsening of his general condition. The patient then received combined administration of doxifluridine (5′-DFUR)/docetaxel (5′-DFUR, 1000 mg/body [666.7 mg/m 2 ], given by consecutive daily administration, orally, for days 1–14; and docetaxel, 80 mg/body [60 mg/m 2 ], on day 8, by venous drip, every 3 weeks). Three courses of this regimen resulted in approximately 90% reduction of the abdominal lymph node size, disappearance of the right cervical lymph node metastasis, reductions of the levels of two tumor markers (carcinoembryonic antigen [CEA] and carbohydrate antigen [CA]19-9), and improvement of his general condition. In total, seven courses of the regimen were carried out. The patient died on day 298 after starting this combined regimen and showed a response period of 126 days. The primary toxicity identified was neutropenia (grade 4), as well as other low-grade (grade 1, 2) hematological and nonhematological toxicities. In the field of gastric cancer treatment, especially for patients showing multiple resistance to anticancer drugs, an effective therapy is critically needed. Received: January 15, 2002 / Accepted: July 8, 2002 Offprint requests to: A. Sato  相似文献   
93.
The study aimed to evaluate the influence of the manipulation surfaces on the physical properties of one-step self-etch adhesives (1-SEAs). Scotchbond Universal (SBU), Clearfil Universal Bond Quick ER (UBQ), and an experimental adhesive (UBQexp) were manipulated on different surfaces: manufacturer’s Teflon-based dispensing dish (TD) or hydroxyapatite plate (HA). After manipulation of the adhesives, the pH of each 1-SEA was measured. Samples of each adhesive/manipulation surface were prepared and subjected to water sorption (WS)/solubility (SL) and flexural strength tests. The modulus of elasticity (E) was measured in dry and wet conditions before and after 24 h water storage, and the percentage of variation of E (ΔE) was calculated. Results were analyzed using the t-test with Bonferroni corrections (α = 0.05). When adhesives were manipulated on the HA plate, there was a significant increase in the adhesives’ pH. WS and SL of all 1-SEAs decreased when the HA was used. Only SBU showed higher flexural strength when manipulated on the HA compared to the manipulation on TD under dry and wet conditions. For each 1-SEA, the use of HA resulted in significantly higher E in dry and wet conditions. ΔE of all adhesives was smaller with the manipulation on HA than on TD. It was concluded that the manipulation of 1-SEA on a hydroxyapatite plate considerably affected the adhesives’ properties.  相似文献   
94.
BackgroundThe primary objective of this phase I, open-label trial was to assess safety and tolerability of tremelimumab monotherapy and combination therapy with durvalumab in Japanese patients with advanced cancer. Tremelimumab is a fully human monoclonal antibody against CTLA-4 in clinical trials; durvalumab is a monoclonal antibody against PD-L1 for the treatment of bladder and lung cancer.MethodsIn part 1, tremelimumab 3 or 10 mg/kg was given every 4 weeks (Q4W) for 6 doses, and thereafter every 12 weeks until discontinuation (n = 8); subsequently tremelimumab 10 mg/kg Q4W for 6 doses/Q12W and thereafter until discontinuation was administered in 41 patients with malignant pleural or peritoneal mesothelioma (MPM). In part 2, tremelimumab 10 mg/kg (Q4W for 6 doses followed by Q12W for 3 doses) was given in combination with durvalumab 15 mg/kg (Q4W for 13 doses) in cohort 1 (n = 4). In cohort 2 (n = 6), tremelimumab 1 mg/kg (Q4W for 4 doses) was given in combination with durvalumab 20 mg/kg (Q4W for 4 doses followed by 10 mg/kg Q2W for 22 doses), while in cohort 3 (n = 6), fixed-dose tremelimumab 75 mg Q4W for 4 doses plus durvalumab 1500 mg Q4W for 13 doses was given.ResultsIn part 1, no dose-limiting toxicities (DLTs) for tremelimumab 3 or 10 mg/kg (Q4W for 6 doses/Q12W thereafter until discontinuation) were observed. Six (75%) patients reported treatment-related adverse events (trAEs). In the MPM dose-expansion cohort, 38 (92.7%) patients reported trAEs. In part 2, one DLT (Grade 4 myasthenia gravis) was reported for tremelimumab 10 mg/kg (Q4W for 6 doses/Q12W for 3 doses) plus durvalumab 15 mg/kg (Q4W for 13 doses). One DLT (Grade 4 hyperglycemia) was reported for tremelimumab 75 mg (Q4W for 4 doses) plus durvalumab 1500 mg (Q4W for 13 doses). Fourteen (87.5%) patients reported trAEs. Tremelimumab demonstrated low immunogenicity; 1 (16.7%) patient developed antidrug antibodies.ConclusionTremelimumab 10 mg/kg (Q4W/Q12W), tremelimumab 1 mg/kg (Q4W) plus durvalumab 20 mg/kg (Q4W/10 mg/kg Q2W), and fixed-dose tremelimumab 75 mg (Q4W) plus durvalumab 1500 mg (Q4W) were safe and tolerable.ClinicalTrials.gov Identifier: NCT02141347 (https://clinicaltrials.gov/ct2/show/NCT02141347)  相似文献   
95.
Polypeptides were used to solubilize functional hydrophobic molecules via a high-speed vibrational milling method. Poly-l-lysine and poly-γ-glutamic acid, which are polypeptides, were able to prepare more highly concentrated water-dispersible complexes of hydrophobic compounds, including fullerenes, organic dyes, and porphyrin derivatives, than conventional water solubilizers, such as cyclodextrins and pullulan. In addition, the polypeptide systems endowed the complexes with long-term stability and resistance against thermal stress, which is advantageous for industrial applications. Furthermore, complexes of polypeptides and porphyrin derivatives showed a photodynamic activity against cancer cells, and the current system improved the dispersibility and storability of guest molecules without compromising their functionality.

Polypeptides were used to solubilize functional hydrophobic molecules via a high-speed vibrational milling method.  相似文献   
96.
The novel coronavirus-19 (COVID-19) pandemic has considerably impacted children’s lives. The aim of this study was to determine whether the pandemic affected mealtime regularity among preschool children and whether maintaining regular mealtimes or changes in mealtime regularity during the pandemic were related to dietary balance, including chronological relationships. This online cross-sectional survey involving individuals registered with a company that provides meals to children aged 2−6 years was conducted in February 2021. Using a 40-point scale, a healthy diet score (HDS) was developed to evaluate children’s dietary balance. The participants were divided into four groups based on their responses, and multiple regression analyses were performed with the HDS as the dependent variable. Maintaining regular mealtimes was associated with practices such as waking and going to bed earlier, less snacking, and eating breakfast every day. Even after adjusting for basic attributes, lifestyle habits, household circumstances, and other factors, regular mealtimes were still positively correlated with the HDS. These findings indicate that maintaining regular mealtimes is associated with higher HDS scores and better lifestyle habits. Furthermore, as the changed HDS was higher in the group whose mealtimes became regular during the pandemic, adopting regular mealtimes may lead to a more balanced diet.  相似文献   
97.
98.
The effects of diced small interfering RNAs (siRNAs) designed for vascular endothelial growth factor (VEGF) on the expression of VEGF in human retinal pigment epithelial cell line ARPE-19 cells in vitro and on corneal angiogenesis in vivo were examined. The exposure to diced siRNAs significantly reduced the VEGF mRNA expression in ARPE-19 cells with minimal toxicity. In suture-induced corneal angiogenesis models, diced siRNAs minimized the severity of angiogenesis. Histological analysis displayed no particular tissue damage in the conjunctiva where siRNA was injected. The approach using diced siRNAs can be a new tool for various neovascular ocular diseases.  相似文献   
99.
Drainage therapy for malignant biliary obstruction (MBO) includes trans-papillary endoscopic retrograde biliary drainage (ERBD), percutaneous transhepatic biliary drainage (PTBD), and trans-gastrointestinal endoscopic ultrasound-guided biliary drainage (EUS-BD). With the development of chemotherapy, many MBO cases end up needing endoscopic reintervention (E-RI) for recurrent biliary obstruction. To achieve a successful E-RI, it is necessary to understand the various findings regarding E-RI in MBO cases reported to date. Therefore, in this review, we focus on E-RI for ERBD of distal MBO, ERBD of hilar MBO, and EUS-BD. To plan an appropriate E-RI strategy for biliary stent occlusion for MBO, the following must be considered on a case-by-case basis: the urgency of the drainage, the cause of the occlusion, the original route of drainage (PTBD/ERBD/EUS-BD), the initial stent used (plastic stent or self-expandable metallic stent), and in the case of self-expandable metallic stents, the type used (fully covered or uncovered). Regardless of the original method of stent placement, if the inflammation caused by obstructive cholangitis is severe and/or the patient is in shock, PTBD should be considered as the first choice. Finally, it is important to keep in mind that in many cases, performing E-RI will be difficult.  相似文献   
100.
Aims: The relationship between left ventricular (LV) function and AF detection in embolic stroke of undetermined source (ESUS) patients with insertable cardiac monitors (ICMs) remains unclear. We investigated the association between LV function and AF detection in patients with ESUS after ICMs implantation. Methods: We enrolled patients with ESUS who underwent ICMs implantation from September 2016 to September 2020 using a single-center, prospective registry. LV systolic and diastolic functions were assessed on precordial echocardiography by LV fractional shortening (LVFS) and average E/e’, respectively. Associations between characteristics of LV function and detection of AF by ICMs were analyzed. Results: Participants comprised 101 patients (median age, 74 years; male, 62%). During a median follow-up period of 442 days (interquartile range (IQR), 202–770 days), AF was detected in 24 patients (24%). Median duration from ICMs implantation to AF detection was 71 days (IQR, 13–150 days). When LVFS and E/e’ were dichotomized by cutoff value, each of low LVFS (<35.5%; adjusted hazard ratio (HR), 4.77; 95% confidence interval (CI), 1.77–12.9) and high E/e’ (≥ 8.65; adjusted HR, 4.56; 95%CI, 1.17–17.7) were independently associated with AF detection after adjusting for age and sex. When patients were divided into four groups according to dichotomized LVFS and E/e’, the combination of low LVFS and high E/e’ was independently associated with AF. Conclusions: In patients with ESUS after ICMs implantation, the LV characteristics of low LVFS and high E/e’ were associated with AF detection.  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