全文获取类型
收费全文 | 1099篇 |
免费 | 214篇 |
国内免费 | 23篇 |
出版年
2024年 | 3篇 |
2023年 | 15篇 |
2022年 | 28篇 |
2021年 | 51篇 |
2020年 | 47篇 |
2019年 | 58篇 |
2018年 | 55篇 |
2017年 | 46篇 |
2016年 | 40篇 |
2015年 | 52篇 |
2014年 | 107篇 |
2013年 | 88篇 |
2012年 | 44篇 |
2011年 | 84篇 |
2010年 | 51篇 |
2009年 | 48篇 |
2008年 | 52篇 |
2007年 | 52篇 |
2006年 | 51篇 |
2005年 | 45篇 |
2004年 | 44篇 |
2003年 | 30篇 |
2002年 | 24篇 |
2001年 | 24篇 |
2000年 | 11篇 |
1999年 | 12篇 |
1998年 | 11篇 |
1997年 | 9篇 |
1996年 | 9篇 |
1995年 | 11篇 |
1994年 | 11篇 |
1993年 | 7篇 |
1992年 | 10篇 |
1991年 | 12篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1987年 | 6篇 |
1986年 | 4篇 |
1985年 | 11篇 |
1984年 | 12篇 |
1983年 | 3篇 |
1982年 | 8篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1979年 | 9篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1973年 | 2篇 |
1971年 | 2篇 |
排序方式: 共有1336条查询结果,搜索用时 31 毫秒
81.
摘要 目的:研究胃炎性纤维性息肉(IFP)的临床特征及内镜下诊断和治疗情况。方法:收集2010.1.1~2021.1.1陕西省人民医院确诊的11例IFP,重点分析其超声内镜表现及临床特征,探索其内镜下治疗价值。结果:IFP多发生在胃窦,均发生于40岁以上人群,男女比例无明显差别,平均直径1.2 cm,大部分临床无症状,有时可引起出血或腹痛。超声内镜示其为粘膜下隆起,孤立、界清,表面多光滑,均起源于粘膜下层,呈低回声,界清,类圆形;内镜下粘膜挖除术治疗IFP,手术时间短,恢复快,并获得完整的标本,术后病理有助确诊。结论:胃炎性纤维性息肉多发生40岁以上人群,多为胃窦孤立的粘膜下病变,多无症状,超声内镜有助于IFP的术前精确评估,内镜下粘膜挖除术是治疗IFP一项安全有效的方法,术后病理最终确诊。 相似文献
82.
Artemisia argyi (AA) is one of the renowned herbs in China often used in the treatment of gastric ulcer (GU). Aiming to predict the active compounds and systematically investigate the mechanisms of Artemisia argyi for GU treatment, the approach of network pharmacology, molecular docking, gene ontology (GO) analysis, and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis were adopted, respectively, in present study. A total of 13 predicted targets of the 103 compounds in Artemisia argyi were obtained. Sorted by pathogenic mechanisms of targets and structure types of compounds, it was revealed that flavonoids and sesquiterpenes had better performance than monoterpenes. The network analysis showed that Phospholipase a2 (PA21B), Sulfotransferase family cytosolic 2b member 1 (ST2B1), Nitric-oxide synthase, endothelial (NOS3), Gastrin (GAST), neutrophil collagenase (MMP-8), Leukotriene A-4 hydrolase (LKHA4), Urease maturation factor HypB (HYPB), and Periplasmic serine endoprotease DegP (HtrA) were the key targets with intensely interaction. The functional enrichment analysis indicated that AA probably produced the gastric mucosa protection effects by synergistically regulating many biological pathways, such as NF-κB signaling pathway, HIF-1 signaling pathway, TNF signaling pathway, VEGF signaling pathway, and Toll-like receptor signaling pathway, etc. In addition, C73 and C15 might be promising leading compounds with good molecular docking score. As a consequence, this study holistically illuminates the active constituents and mechanisms based on data analysis, which contributes to searching for leading compounds and the development of new drugs for gastric ulcer. 相似文献
83.
Zhongyin Yang Chen Li Chao Yan Jianfang Li Min Yan Bingya Liu Zhenggang Zhu Yingli Wu Qinlong Gu 《生物化学与生物物理学报:疾病的分子基础》2019,1865(1):181-192
The kinesin family member 14 (KIF14) is a potential oncogene and is involved in the metastasis of various cancers. Nevertheless, its function in gastric cancer (GC) remains poorly defined. The expression of KIF14 was examined in GC cell lines and a clinical cohort of GC specimens by qPCR, western blotting and immunohistochemistry (IHC) staining. The relationship between KIF14 expression and the clinicopathological features was analyzed. The effect of KIF14 on cell proliferation, colony formation, invasion and migration were investigated in vitro and in vivo. The expression of KIF14 was significantly increased in the GC tissues and cell lines. High KIF14 expression was associated with tumor stage, tumor-node-metastasis (TNM) stage and metastasis. KIF14 was an independent prognostic factor for the overall survival of GC, and a higher expression of KIF14 predicted a poorer survival. KIF14 silencing resulted in attenuated proliferation, invasion and migration in human gastric cancer cells, whereas KIF14 ectopic expression facilitated these biological abilities. Notably, the depressed expression of KIF14 inhibited Akt phosphorylation, while overexpressed KIF14 augmented Akt phosphorylation. Additionally, there was a significant correlation between the expression of KIF14 and p?Akt in GC tissues. Importantly, the proliferation, invasion and migration of the GC cells, which was promoted by KIF14 overexpression, was abolished by the Akt inhibitor MK-2206, while Akt overexpression greatly rescued the effects induced by KIF14 knockdown. Our findings are the first to demonstrate that KIF14 is overexpressed in GC, is correlated with poor prognosis and plays a crucial role in the progression and metastasis of GC. 相似文献
84.
We present a model and semiparametric estimation procedures for analysis of survival data with cross-effects (CE) of survival functions. Finite sample properties of the estimators are analyzed by simulation. A goodness-of-fit test for the proportional hazards model against the CE model is proposed. The well known data concerning effects of chemotherapy and radiotherapy on the survival times of gastric cancer patients is analyzed as an example. 相似文献
85.
Interleukin-6 increases vascular endothelial growth factor and angiogenesis in gastric carcinoma 总被引:8,自引:1,他引:7
Huang SP Wu MS Shun CT Wang HP Lin MT Kuo ML Lin JT 《Journal of biomedical science》2004,11(4):517-527
Interleukin-6 (IL-6) is a proinflammatory cytokine associated with the disease status of gastric carcinoma (GC). Vascular endothelial growth factor (VEGF) is a potent tumor angiogenic factor in GC. In this study, we attempted to clarify whether IL-6 can regulate VEGF and angiogenesis in GC. GC samples from 54 surgical specimens were subjected to immunohistochemical examination of IL-6, VEGF, and tumor microvessels, and results showed that IL-6 was positively correlated with VEGF expression and tumor vasculature. We determined VEGF expression in four GC cell lines by ELISA, revealing that GC cells can produce significant amount of VEGF with increasing dose and duration of IL-6 stimulation. Next, a luciferase reporter gene assay was employed to determine the signaling pathway driving the VEGF promoter by IL-6, which showed that the JAK/STAT pathway is involved in the stimulation of VEGF gene expression. The effects of IL-6 on angiogenesis in vitro and in vivo were evaluated by HUVEC studies and the Matrigel plug assay, respectively. Results showed that IL-6 effectively promoted HUVEC proliferation and tube formation in vitro and Matrigel plug vascularization in vivo, primarily by inducing VEGF in GC. This study provides evidence that the multifunctional cytokine, IL-6, may induce VEGF expression which increases angiogenesis in gastric carcinogenesis. 相似文献
86.
87.
Gene targeting techniques have revolutionized the investigation of the effects of bioactive substances in pathological and physiological conditions. Histamine synthesis is uniquely catalyzed by L-histidine decarboxylase. The knockout mice of this gene express no histamine-producing activity and lack histamine. These mice have been used to examine the mechanisms of histamine in several known phenotypes, e.g., gastric acid secretion, contraction of smooth muscles, vascular permeability, and awakening, and have also been used to explore unreported effects of histamine in the whole body. First, we will review the former mechanisms and then move to the latter, new effects. Especially, in the latter mechanisms, we focus on several important roles of histamine in angiogenesis, neutrophil and eosinophil recruitment, bacterial infection, and systemic anaphylaxis in this review. Moreover, to our surprise, the morphology of mast cells in the knockout mice was severely affected by the absence of histamine in terms of their granules. 相似文献
88.
Masaoka T Suzuki H Hosoda H Ota T Minegishi Y Nagata H Kangawa K Ishii H 《FEBS letters》2003,550(1-3):64-68
Human saliva, which contains nitrite, is normally mixed with gastric juice, which contains ascorbic acid (AA). When saliva was mixed with an acidic buffer in the presence of 0.1 mM AA, rapid nitric oxide formation and oxygen uptake were observed. The oxygen uptake was due to the oxidation of nitric oxide, which was formed by AA-dependent reduction of nitrite under acidic conditions, by molecular oxygen. A salivary component SCN− enhanced the nitric oxide formation and oxygen uptake by the AA/nitrite system. The oxygen uptake by the AA/nitrite/SCN− system was also observed in an acidic buffer solution. These results suggest that oxygen is normally taken up in the stomach when saliva and gastric juice are mixed. 相似文献
89.
Endomorphins 1 and 2 reduce relaxant non-adrenergic,non-cholinergic neurotransmission in rat gastric fundus 总被引:6,自引:0,他引:6
It is now well established that opioids modulate cholinergic excitatory neurotransmission in the gastrointestinal tract. The aim of the present study was to characterize a possible effect of endomorphins on nonadrenergic, noncholinergic (NANC) relaxant neurotransmission in the rat gastric fundus in vitro. The drugs used in the experiments were the endogenous mu-opioid receptors (MORs) endomorphin 1 and 2 and the mu-opioid receptor antagonist CTAP (D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2). CTAP left the basal tonus and the spontaneous activity of the preparation unchanged. Electrical field stimulation (EFS) under NANC conditions at frequencies ranging from 0.5 to 16 Hz caused a frequency-dependent relaxant response on the 5-hydoxytryptamine (5-HT) (10(-7) M) precontracted smooth-muscle strip. Both endomorphin 1 and endomorphin 2 significantly reduced this relaxation in a concentration-dependent manner. Endomorphin 1 proved to be more potent in reducing the relaxant responses. The endomorphin effects were significantly reversed by the MOR antagonist CTAP. CTAP itself did not influence the EFS-induced relaxation. In summary, these data provide evidence that the endogenous MOR agonists endomorphin 1 and 2 can reduce nonadrenergic, noncholinergic neurotransmission in the rat gastric fundus smooth muscle via a pathway involving MORs. The physiological relevance of these findings remains to be established, since the data presented suggest that the endomorphins act as neuromodulators within NANC relaxant neurotransmission. 相似文献
90.
Intestinal mucosal capsaicin-sensitive afferent nerves mediate, in part, the mesenteric hyperemia after intraduodenal acidification. The hyperemia plays a role in protecting the duodenal mucosa against acid damage. We tested the hypothesis that bradykinin contributes to this protective hyperemia. A specific antagonist of bradykinin will attenuate the hyperemia and exacerbate duodenal villous damage induced by acid. Study 1: Intravenous vehicle, or the specific bradykinin B2 receptor antagonist (HOE 140) was administered to anesthetized rats. This was followed by intraduodenal bolus administration of 160 microM capsaicin or 0.1 N HCl, and then intravenous bradykinin. Study 2: Intravenous administration of vehicle or HOE 140 was followed by duodenal perfusion with 0.1 N HCl. Superior mesenteric artery blood flow (pulsed Doppler flowmetry) (Study 1) and duodenal villous damage (histology) (Study 2) were recorded. HOE 140 significantly reduced the hyperemia induced by bradykinin and intraduodenal capsaicin or acid. Deep villous injury was significantly increased after treatment with HOE 140. These findings support the hypothesis that acid-induced and afferent nerve-mediated mesenteric hyperemia is modulated by a mechanism that involves bradykinin B2 receptor. Antagonism of bradykinin B2 receptor also increased acid-induced deep duodenal villous damage. Thus, maintenance of bradykinin-mediated mesenteric hyperemia, is a previous unrecognized mechanism associated with protection of the rat duodenal mucosa against acid-induced damage. 相似文献