全文获取类型
收费全文 | 395篇 |
免费 | 32篇 |
专业分类
电工技术 | 1篇 |
综合类 | 3篇 |
化学工业 | 138篇 |
金属工艺 | 9篇 |
机械仪表 | 7篇 |
建筑科学 | 20篇 |
矿业工程 | 1篇 |
能源动力 | 5篇 |
轻工业 | 75篇 |
水利工程 | 4篇 |
无线电 | 6篇 |
一般工业技术 | 69篇 |
冶金工业 | 44篇 |
原子能技术 | 1篇 |
自动化技术 | 44篇 |
出版年
2023年 | 11篇 |
2022年 | 17篇 |
2021年 | 19篇 |
2020年 | 13篇 |
2019年 | 9篇 |
2018年 | 18篇 |
2017年 | 13篇 |
2016年 | 20篇 |
2015年 | 10篇 |
2014年 | 28篇 |
2013年 | 19篇 |
2012年 | 30篇 |
2011年 | 34篇 |
2010年 | 22篇 |
2009年 | 20篇 |
2008年 | 23篇 |
2007年 | 17篇 |
2006年 | 17篇 |
2005年 | 15篇 |
2004年 | 7篇 |
2003年 | 4篇 |
2002年 | 6篇 |
2001年 | 7篇 |
2000年 | 6篇 |
1999年 | 2篇 |
1998年 | 6篇 |
1997年 | 6篇 |
1996年 | 9篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 2篇 |
排序方式: 共有427条查询结果,搜索用时 15 毫秒
331.
Jasmin Strutz Kathrin Baumann Elisa Weiss Ursula Hiden 《International journal of molecular sciences》2021,22(24)
Gestational diabetes (GDM) and preeclampsia (PE) are associated with fetal hyperglycemia, fetal hypoxia, or both. These adverse conditions may compromise fetal and placental endothelial cells. In fact, GDM and PE affect feto-placental endothelial function and also program endothelial function and cardiovascular disease risk of the offspring in the long-term. MicroRNAs are short, non-coding RNAs that regulate protein translation and fine tune biological processes. A group of microRNAs termed angiomiRs is particularly involved in the regulation of endothelial function. We hypothesized that transient hyperglycemia and hypoxia may alter angiomiR expression in feto-placental endothelial cells (fpEC). Thus, we isolated primary fpEC after normal, uncomplicated pregnancy, and induced hyperglycemia (25 mM) and hypoxia (6.5%) for 72 h, followed by reversal to normal conditions for another 72 h. Current vs. transient effects on angiomiR profiles were analyzed by RT-qPCR and subjected to miRNA pathway analyses using DIANA miRPath, MIENTURNET and miRPathDB. Both current and transient hypoxia affected angiomiR profile stronger than current and transient hyperglycemia. Both stimuli altered more angiomiRs transiently, i.e., followed by 72 h culture at control conditions. Pathway analysis revealed that hypoxia significantly altered the pathway ‘Proteoglycans in cancer’. Transient hypoxia specifically affected miRNAs related to ‘adherens junction’. Our data reveal that hyperglycemia and hypoxia induce memory effects on angiomiR expression in fpEC. Such memory effects may contribute to long-term adaption and maladaption to hyperglycemia and hypoxia. 相似文献
332.
Scherer K Szabó I Rösler U Appel B Hensel A Nöckler K 《Journal of food protection》2008,71(4):699-705
This is the first longitudinal study conducted over the entire 5-month fattening period in pigs to investigate the infection dynamics of Salmonella Typhimurium and the association between antibody response and the prevalence of these bacteria in feces. A total of 16 weaning pigs were infected with Salmonella Typhimurium DT104 followed by clinical examination and blood and fecal sampling until slaughter 138 days postinoculation. To investigate fecal shedding rates and distribution patterns of Salmonella in internal organs regarding premortem stress, one group of swine was transported before slaughter; the other group was slaughtered without being transported. A positive correlation between bacteremia-associated fever and fecal shedding rate was observed, although 69% (11 of 16) of infected pigs had no diarrhea. All animals excreted Salmonella Typhimurium at high levels within 2 weeks postinoculation; thereafter, the number of positive pigs declined and Salmonella shedding became intermittent. In contrast, the proportion of pigs that tested seropositive was higher over the entire fattening period (except during the first 3 weeks postinoculation), revealing the advantage of enzyme-linked immunosorbent assay for Salmonella screening on herd level. Concerning the distribution in internal organs and cross-contamination during slaughter, the highest level of Salmonella was detected in tonsils and jejunal and ileocecal lymph nodes, whereas salmonellae could not be detected in muscle, spleen, and liver. No specific influence of transport-induced stress on Salmonella shedding rates in feces and distribution patterns in organs was observed. 相似文献
333.
Roman Tremmel Anne T. Nies Barbara A. C. van Eijck Niklas Handin Mathias Haag Stefan Winter Florian A. Büttner Charlotte Klz Franziska Klein Pascale Mazzola Ute Hofmann Kathrin Klein Per Hoffmann Markus M. Nthen Fabienne Z. Gaugaz Per Artursson Matthias Schwab Elke Schaeffeler 《International journal of molecular sciences》2022,23(13)
334.
Achenbach TV Brunner B Heermeier K 《Chembiochem : a European journal of chemical biology》2003,4(10):928-935
The postgenomic era is characterized by an almost intimidating amount of information regarding the sequences and expression of previously unknown genes. In response, researchers have developed an increasing interest in functional studies. At the start of such a study, one may have little more than sequence information and bioinformatic annotation. The next step is to hypothesize a potential role in the context of a cell. Testing of the hypothesis needs to be fast, cheap, and applicable to a large number of genes. Knockdown methods that rely on binding of antisense oligonucleotides to mRNA combined with a subsequent functional assay in cell culture fulfil these requirements: sequence information is sufficient for synthesis of active inhibitors. Depending on the in vitro model chosen, knockdown of gene expression can be achieved with medium or even high throughput. The two most popular methods of knockdown in cell culture are the use of antisense oligonucleotides that rely on ribonuclease H (RNAse H)-dependent cleavage of mRNA, and RNA interference triggered by small double-stranded RNA molecules. Both methods act in a sequence-specific manner and can give efficient knockdown. In both cases, researchers struggle with nonspecific "off-target" effects and the difficulty of site selection. Studies that compare the methods differ in their judgment as to which method is superior. 相似文献
335.
Beatrice Hanusch Kathrin Sinningen Folke Brinkmann Stefanie Dillenhfer Mirjam Frank Karl-Heinz Jckel Cordula Koerner-Rettberg Martin Holtmann Tanja Legenbauer Christian Langrock Thomas Reinehr Patricia Maasjosthusmann Bibiana Beckmann Eckard Hamelmann Dimitrios Tsikas Thomas Lücke 《International journal of molecular sciences》2022,23(4)
Introduction: L-Arginine (Arg) is a semi-essential amino acid. Constitutive and inducible nitric oxide synthase (NOS) isoforms convert Arg to nitric oxide (NO), a potent vaso- and bronchodilator with multiple biological functions. Atopic dermatitis (AD) and bronchial asthma (BA) are atopic diseases affecting many children globally. Several studies analyzed NO in airways, yet the systemic synthesis of NO in AD and BA in children with BA, AD or both is elusive. Methods: In a multicenter study, blood and urine were obtained from 130 of 302 participating children for the measurement of metabolites of the Arg/NO pathway (BA 31.5%; AD 5.4%; AD + BA 36.1%; attention deficit hyperactivity disorder (ADHD) 12.3%). In plasma and urine amino acids Arg and homoarginine (hArg), both substrates of NOS, asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA), both inhibitors of NOS, dimethylamine (DMA), and nitrite and nitrate, were measured by gas chromatography–mass spectrometry. Malondialdehyde (MDA) was measured in plasma and urine samples to evaluate possible effects of oxidative stress. Results: There were no differences in the Arg/NO pathway between the groups of children with different atopic diseases. In comparison to children with ADHD, children with AD, BA or AD and BA had higher plasma nitrite (p < 0.001) and nitrate (p < 0.001) concentrations, suggesting higher systemic NO synthesis in AD and BA. Urinary excretion of DMA was also higher (p = 0.028) in AD and BA compared to patients with ADHD, suggesting elevated ADMA metabolization. Discussion/Conclusion: The Arg/NO pathway is activated in atopic diseases independent of severity. Systemic NO synthesis is increased in children with an atopic disease. Plasma and urinary MDA levels did not differ between the groups, suggesting no effect of oxidative stress on the Arg/NO pathway in atopic diseases. 相似文献
336.
Max Schuller Monika Oberhuber Barbara Prietl Elmar Zügner Eva-Maria Prugger Christoph Magnes Alexander H. Kirsch Sabine Schmaldienst Thomas Pieber Marianne Brodmann Alexander R. Rosenkranz Philipp Eller Kathrin Eller 《International journal of molecular sciences》2022,23(22)
Coronavirus disease 2019 (COVID-19)-induced metabolic alterations have been proposed as a source for prognostic biomarkers and may harbor potential for therapeutic exploitation. However, the metabolic impact of COVID-19 in hemodialysis (HD), a setting of profound a priori alterations, remains unstudied. To evaluate potential COVID-19 biomarkers in end-stage kidney disease (CKD G5), we analyzed the plasma metabolites in different COVID-19 stages in patients with or without HD. We recruited 18 and 9 asymptomatic and mild, 11 and 11 moderate, 2 and 13 severely affected, and 10 and 6 uninfected HD and non-HD patients, respectively. Plasma samples were taken at the time of diagnosis and/or upon admission to the hospital and analyzed by targeted metabolomics and cytokine/chemokine profiling. Targeted metabolomics confirmed stage-dependent alterations of the metabolome in non-HD patients with COVID-19, which were less pronounced in HD patients. Elevated kynurenine levels and lipid dysregulation, shown by an increase in circulating free fatty acids and a decrease in lysophospholipids, could distinguish patients with moderate COVID-19 from non-infected individuals in both groups. Kynurenine and lipid alterations were also associated with ICAM-1 and IL-15 levels in HD and non-HD patients. Our findings support the kynurenine pathway and plasma lipids as universal biomarkers of moderate and severe COVID-19 independent of kidney function. 相似文献
337.
Electromagnetic Functionalization of Wide‐Bandgap Dielectric Oxides by Boron Interstitial Doping
下载免费PDF全文
![点击此处可从《Advanced materials (Deerfield Beach, Fla.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dae‐Sung Park Gregory J. Rees Haiyuan Wang Diana Rata Andrew J. Morris Igor V. Maznichenko Sergey Ostanin Akash Bhatnagar Chel‐Jong Choi Ragnar D. B. Jónsson Kai Kaufmann Reza Kashtiban Marc Walker Cheng‐Tien Chiang Einar B. Thorsteinsson Zhengdong Luo In‐Sung Park John V. Hanna Ingrid Mertig Kathrin Dörr Hafliði P. Gíslason Chris F. McConville 《Advanced materials (Deerfield Beach, Fla.)》2018,30(39)
A surge in interest of oxide‐based materials is testimony for their potential utility in a wide array of device applications and offers a fascinating landscape for tuning the functional properties through a variety of physical and chemical parameters. In particular, selective electronic/defect doping has been demonstrated to be vital in tailoring novel functionalities, not existing in the bulk host oxides. Here, an extraordinary interstitial doping effect is demonstrated centered around a light element, boron (B). The host matrix is a novel composite system, made from discrete bulk LaAlO3:LaBO3 compounds. The findings show a spontaneous ordering of the interstitial B cations within the host LaAlO3 lattices, and subsequent spin‐polarized charge injection into the neighboring cations. This leads to a series of remarkable cation‐dominated electrical switching and high‐temperature ferromagnetism. Hence, the induced interstitial doping serves to transform a nonmagnetic insulating bulk oxide into a ferromagnetic ionic–electronic conductor. This unique interstitial B doping effect upon its control is proposed to be as a general route for extracting/modifying multifunctional properties in bulk oxides utilized in energy and spin‐based applications. 相似文献
338.
Dr. Kathrin Brömmel Sarah Maskri Dr. Etmar Bulk Dr. Zoltan Pethő Dr. Marius Rieke Prof. Dr. Thomas Budde Dr. Oliver Koch Prof. Dr. Albrecht Schwab Prof. Dr. Bernhard Wünsch 《ChemMedChem》2020,15(24):2462-2469
The Ca2+ activated potassium channel 3.1 (KCa3.1) is involved in critical steps of the metastatic cascade, such as proliferation, migration, invasion and extravasation. Therefore, a fast and efficient protocol for imaging of KCa3.1 channels was envisaged. The novel fluorescently labeled small molecule imaging probes 1 and 2 were synthesized by connecting a dimethylpyrrole-based BODIPY dye with a derivative of the KCa3.1 channel inhibitor senicapoc via linkers of different length. Patch-clamp experiments revealed the inhibition of KCa3.1 channels by the probes confirming interaction with the channel. Both probes 1 and 2 were able to stain KCa3.1 channels in non-small-cell lung cancer (NSCLC) cells following a simple, fast and efficient protocol. Pre-incubation with unlabeled senicapoc removed the punctate staining pattern showing the specificity of the new probes 1 and 2 . Staining of the channel with the fluorescently labeled senicapoc derivatives 1 or 2 or with antibody-based indirect immunofluorescence yielded identical or very similar densities of stained KCa3.1 channels. However, co-staining using both methods did not lead to the expected overlapping punctate staining pattern. This observation was explained by docking studies showing that the antibody used for indirect immunofluorescence and the probes 1 and 2 label different channel populations. Whereas the antibody binds at the closed channel conformation, the probes 1 and 2 bind within the open channel. 相似文献
339.
Matthias A. Fante Sonja-Maria Decking Christina Bruss Stephan Schreml Peter J. Siska Marina Kreutz Kathrin Renner 《International journal of molecular sciences》2021,22(5)
Heat-inactivation of sera is used to reduce possible disturbing effects of complement factors in cell-culture experiments, but it is controversially discussed whether this procedure is appropriate or could be neglected. Here, we report a strong impact of heat-inactivation of human sera on the activation and effector functions of human CD4+ T cells. While T cells cultured with native sera were characterized by a higher proliferation rate and higher expression of CD28, heat-inactivated sera shaped T cells towards on-blast formation, higher cytokine secretion (interferon γ, tumor necrosis factor, and interleukin-17), stronger CD69 and PD-1 expression, and increased metabolic activity. Heat-inactivated sera contained reduced amounts of complement factors and regulators like C1 inhibitor, but increased concentrations of circulating immune complexes. Substitution of C1 inhibitor reduced the beneficial effect of heat-inactivation in terms of cytokine release, whereas surface-molecule expression was affected by the addition of complex forming anti-C1q antibody. Our data clearly demonstrate a beneficial effect of heat-inactivation of human sera for T cell experiments but indicate that beside complement regulators and immune complexes other components might be relevant. Beyond that, this study further underpins the strong impact of the complement system on T cell function. 相似文献
340.
Saeed Katiraei Margreet R. de Vries Alice H. Costain Kathrin Thiem Lisa R. Hoving Janna A. van Diepen Hermelijn H. Smits Kristien E. Bouter Patrick C. N. Rensen Paul H. A. Quax Max Nieuwdorp Mihai G. Netea Willem M. de Vos Patrice D. Cani Clara Belzer Ko Willems van Dijk Jimmy F. P. Berbée Vanessa van Harmelen 《Molecular nutrition & food research》2020,64(15):1900732