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   279篇
  免费   11篇
  国内免费   9篇
耳鼻咽喉   1篇
儿科学   12篇
妇产科学   3篇
基础医学   33篇
口腔科学   8篇
临床医学   47篇
内科学   47篇
皮肤病学   1篇
神经病学   7篇
特种医学   6篇
外科学   20篇
综合类   43篇
预防医学   15篇
药学   34篇
中国医学   20篇
肿瘤学   2篇
  2023年   3篇
  2022年   5篇
  2021年   7篇
  2020年   12篇
  2019年   11篇
  2018年   3篇
  2017年   1篇
  2016年   7篇
  2015年   11篇
  2014年   6篇
  2013年   28篇
  2012年   13篇
  2011年   14篇
  2010年   11篇
  2009年   10篇
  2008年   10篇
  2007年   14篇
  2006年   17篇
  2005年   8篇
  2004年   7篇
  2003年   11篇
  2002年   9篇
  2001年   8篇
  2000年   7篇
  1999年   2篇
  1998年   4篇
  1997年   3篇
  1996年   4篇
  1995年   9篇
  1994年   3篇
  1992年   2篇
  1991年   1篇
  1990年   3篇
  1989年   3篇
  1988年   5篇
  1987年   1篇
  1986年   1篇
  1985年   2篇
  1984年   9篇
  1982年   2篇
  1981年   1篇
  1980年   1篇
  1979年   3篇
  1977年   4篇
  1976年   1篇
  1974年   1篇
  1973年   1篇
排序方式: 共有299条查询结果,搜索用时 312 毫秒
1.
我国α—淀粉酶(EC3.2.1.1)生产是用枯草杆菌BF—7658菌株,它产生的酶是个复杂酶系。其中混杂的蛋白酶未见酸性蛋白酶。发酵液经热处理后,测蛋白酶活力。结果,碱性蛋白酶耐热性比中性蛋白酶强。发酵液经55℃,30分钟热处理后,碱性蛋白蛋残存活力与室温(20~25℃)下碱性蛋白酶活力相差不显著(P>0.05),而中性蛋白酶则相差显著(P<0.05)。用电泳法观察发酵液蛋白酶电泳谱型,显示两条蛋白酶区带。  相似文献   
2.
Summary Tumour tissue from a lung cancer patient who showed elevated serum amylase and adrenocorticotropin (ACTH) was studied ultrastructurally, immunohistochemically and biochemically. Histologically the tumour was a small cell carcinoma. On electron microscopic examination the tumour cells contained large zymogen-like granules within the cytoplasm. Furthermore, cells which possessed many small dense core granules of the endocrine type were also observed. It was of interest that the large zymogen-like granule-containing tumour cells had microvilli at the apical border, connected by desmosomes and forming lumina showing adenocarcinomatous differentiation. Electrophoretic analysis of the serum revealed that the major elevated amylase was of the salivary type with minor components. Immunostaining clearly demonstrated that most of the tumour cells possessed immunoreactive ACTH, whereas salivary amylase was only found in occasional clusters of the tumour cells. The results seem to indicate that the tumour showed both endocrine and exocrine characteristics - an amphicrine carcinoma, expressing amylase and ACTH simultaneously.  相似文献   
3.
4.
Acetylcholine (ACh) released from vagal terminals increases the permeability of the pancreatic acinar membrane to Na+ and Ca2+ ions. In this report, we compare the induced changes in intracellular Na+ and Ca2+ electrode potentials (ENa and ECa) due to ACh-stimulation of acini with those observed during stimulation with the calcium ionophore, A23187, which mimicks the action of ACh on pancreatic secretion. Stimulation with ACh concentrations varying from 10–8 to 10–5 M and with A23187 concentrations of 10–6 and 10–5 M caused parallel increases in cytosolic Ca2+ and Na+ ([Ca]i, [Na]i). The magnitude of the increases in [Ca]i and [Na]i due to A23187-stimulation further indicate that when presented with a calcium challenge the acinar cells continue to regulate [Ca]i close to physiological levels and suggest that the observed increases in ionized calcium could reflect much larger increases in complexed Ca2+. ACh-stimulation following removal of either extracellular Na+ or Ca2+ ions, eliminated the intracellular increases found when the removed ions is present, but did not affect the increases usually found with the other ion. The independence of the permeability changes to either the presence of Ca2+ or Na+ indicates the ACh-induced currents carried by Na+ and Ca2+ are also independent. The selective translocation of Na+ and Ca2+ during acetylcholine-stimulation in a manner analogous to the changes observed when ionophore A23187 was used as stimulus, indicates the ability of the activated acinar membrane to function as an ionophore.  相似文献   
5.
尿胰蛋白酶原—2测定对急性胰腺炎的早期诊断价值   总被引:1,自引:0,他引:1  
目的 探讨尿胰蛋白酶原-2测定在急腹症中筛选急性胰腺炎的价值。方法 对346例连续就诊的急腹症病人同时测定尿胰蛋白酶原-2及血、尿淀粉酶。结果 41例急性胰腺炎中有38例尿胰蛋白酶原-2阳性,敏感性为92.7%,305例非胰腺炎的急腹症病人有15例假阳性,特异性为95.1%。5例重症急性胰腺炎中尿胰蛋白酶原-2全部阳性。结论 尿胰蛋白酶原-2是急腹症病人筛选急性胰腺炎快而简便的方法,具有较高的特异性和敏感性。  相似文献   
6.
目的:观察通腑解毒方联合六合丹辅助西医治疗急性胰腺炎的临床疗效及对患者肠功能屏障、肝功能、炎症反应的影响。方法:将157例急性胰腺炎患者采用简单随机法分为西医组(n=78)和辨证组(n=79)。西医组给予西医治疗,辨证组在西医组治疗基础上给予通腑解毒方灌肠联合六合丹外敷治疗。比较两组临床相关指标、中医症候积分、疗效、28 d病死率、血清学指标。结果:辨证组总有效率高于西医组,腹痛、腹胀缓解时间及首次排便时间、进食时间均短于西医组(均P<0.05)。治疗后,两组各项中医症候积分较治疗前下降,且辨证组低于西医组(均P<0.05)。治疗后,两组血、尿淀粉酶及二胺氧化酶(DAO)、D-乳酸、谷草转氨酶(AST)、C反应蛋白(CRP)、单核细胞趋化因子-1(MCP-1)、谷丙转氨酶(ALT)水平均较治疗前下降,且辨证组低于西医组(均P<0.05)。两组28 d病死率比较,差异无统计学意义(P>0.05)。结论:通腑解毒方联合六合丹辅助西医治疗急性胰腺炎可促进腹痛、腹胀的缓解,保护肠功能屏障,抑制炎症反应,提高疗效。  相似文献   
7.
Summary Amylase and K+ release were measured in slices obtained from innervated and sympathetically denervated rat parotid glands. Amylase release induced by noradrenaline was found to be increased after chronic denervation. The postjunctional component of supersensitivity to noradrenaline was evidenced by an increase in the maximal response to this agonist. The maximal response of denervated glands was blocked by propranolol 10–5 M. On the other hand, chronic denervation did not modify the -adrenoceptor-mediated response, K+ release, either in the presence or in the absence of ouabain. It is concluded that, after sympathetic denervation, postjunctional supersensitivity develops for the -adrenoceptor-mediated but not for the -adrenoceptors-mediated effects of noradrenaline.  相似文献   
8.
Sialomrgaly of suhmandibultir gland, whether inflammatory or neoplastic can be clinically mistaken for lymphoid metastasis especially when encountered in an elderly patient. Other than the neoptastic lesions and usual inflammatory lesions rarely amylase crystalloids can evoke a granulomatous response and can result in sialomegaly. We report an interesting case which presented as a submandibular swelling and was clinically diagnosed as metastasis where the diagnosis of granulomatous response to crystalloids was made at FNAC. The aim of this report is to bring an awareness of the existence of such lesions and to highlight the role of FNAC in diagnosis of such lesions in order to avoid unnecessary surgeries.  相似文献   
9.
BackgroundIt is new clinical interest higher serum amylase level with pancreatitis after pancreaticoduodenectomy (PD) correlates with postoperative pancreatic fistula (POPF). Nevertheless, its evidence and study were scarce. We aimed to investigate correlation of serum amylase level immediate after PD and POPF occurrence.MethodsOf 163 patients who underwent PD at between January 2009 and December 2019, retrospective analysis was conducted to identify risk factors including serum amylase level immediate after PD for POPF occurrence.ResultsOverall incidence of POPF (25/163) was 15.3%. The patients occurred a POPF had significantly higher level of serum amylase on POD0 compared to in whom without a POPF (414 vs 253, p < 0.001). In univariate analysis, ASA classification, post pancreatectomy acute pancreatitis (POAP, serum amylase on POD0 >285IU/L) and Fistula Risk Grade were correlated with POPF occurrence. In multivariable analysis, Fistula risk grade and POAP were significantly associated with developing POPF.ConclusionIn patients with higher serum amylase (>285IU/L) on POD0 with higher fistula risk grade, comprehensive management to achieve mitigation of POPF is important.  相似文献   
10.
《Pancreatology》2022,22(4):539-546
IntroductionThe prevalence of increased pancreatic enzymes (elevated serum amylase and/or lipase) and its relationship to clinical outcomes in patients with coronavirus disease 2019 (COVID-19) infection is not known.MethodsA systematic review and meta-analysis of relevant studies reporting prevalence and impact of increased pancreatic enzymes (defined as an elevation in amylase and/or lipase levels above the upper limit of normal [ULN] value) in COVID-19 was undertaken.ResultsA total of 36,496 patients from 21 studies were included for this meta-analysis. The overall prevalence and mortality for increased pancreatic enzymes (>ULN) in COVID-19 were 25.4% (95% CI, 15.8%–36.2%) and 34.6% (95% CI, 25.5%–44.4%), respectively. The overall prevalence and mortality for increased pancreatic enzymes (>3 × ULN) were 6.1% (95% CI, 3.6%–9.2%) and 39.2% (95% CI, 18.7%–61.6%), respectively. Patients with increased pancreatic enzymes, including elevated serum lipase or amylase of either type, had worse clinical outcomes, including need for ICU admission, mechanical ventilation and mortality.DiscussionIncreased pancreatic enzymes is frequent and may exacerbate the consequences of COVID-19 infection.  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