全文获取类型
收费全文 | 361篇 |
免费 | 45篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 167篇 |
金属工艺 | 4篇 |
机械仪表 | 6篇 |
建筑科学 | 6篇 |
能源动力 | 5篇 |
轻工业 | 41篇 |
水利工程 | 3篇 |
无线电 | 18篇 |
一般工业技术 | 68篇 |
冶金工业 | 40篇 |
原子能技术 | 2篇 |
自动化技术 | 44篇 |
出版年
2024年 | 1篇 |
2023年 | 7篇 |
2022年 | 34篇 |
2021年 | 55篇 |
2020年 | 22篇 |
2019年 | 13篇 |
2018年 | 10篇 |
2017年 | 12篇 |
2016年 | 34篇 |
2015年 | 11篇 |
2014年 | 3篇 |
2013年 | 20篇 |
2012年 | 22篇 |
2011年 | 19篇 |
2010年 | 7篇 |
2009年 | 13篇 |
2008年 | 18篇 |
2007年 | 5篇 |
2006年 | 9篇 |
2005年 | 8篇 |
2004年 | 5篇 |
2003年 | 11篇 |
2002年 | 7篇 |
2001年 | 2篇 |
2000年 | 6篇 |
1999年 | 6篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 8篇 |
1995年 | 3篇 |
1993年 | 5篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1972年 | 1篇 |
1965年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有406条查询结果,搜索用时 15 毫秒
311.
Marta Woroszyo Daria Ciecholewska-Juko Adam Junka Radosaw Drozd Marcin Wardach Pawe Migda Patrycja Szymczyk-Zikowska Daniel Styburski Karol Fijakowski 《International journal of molecular sciences》2021,22(22)
Methicillin-resistant strains of Staphylococcus aureus (MRSA) have developed resistance to most β-lactam antibiotics and have become a global health issue. In this work, we analyzed the impact of a rotating magnetic field (RMF) of well-defined and strictly controlled characteristics coupled with β-lactam antibiotics against a total of 28 methicillin-resistant and sensitive S. aureus strains. The results indicate that the application of RMF combined with β-lactam antibiotics correlated with favorable changes in growth inhibition zones or in minimal inhibitory concentrations of the antibiotics compared to controls unexposed to RMF. Fluorescence microscopy indicated a drop in the relative number of cells with intact cell walls after exposure to RMF. These findings were additionally supported by the use of SEM and TEM microscopy, which revealed morphological alterations of RMF-exposed cells manifested by change of shape, drop in cell wall density and cytoplasm condensation. The obtained results indicate that the originally limited impact of β-lactam antibiotics in MRSA is boosted by the disturbances caused by RMF in the bacterial cell walls. Taking into account the high clinical need for new therapeutic options, effective against MRSA, the data presented in this study have high developmental potential and could serve as a basis for new treatment options for MRSA infections. 相似文献
312.
Elena V. Gerasimova Tatiana V. Popkova Daria A. Gerasimova Tatiana V. Kirichenko 《International journal of molecular sciences》2022,23(9)
One of the problems of modern medical science is cardiovascular pathology caused by atherosclerotic vascular lesions in patients with autoimmune rheumatic diseases (ARDs). The similarity between the mechanisms of the immunopathogenesis of ARD and chronic low-grade inflammation in atherosclerosis draws attention. According to modern concepts, chronic inflammation associated with uncontrolled activation of both innate and acquired immunity plays a fundamental role in all stages of ARDs and atherosclerotic processes. Macrophage monocytes play an important role among the numerous immune cells and mediators involved in the immunopathogenesis of both ARDs and atherosclerosis. An imbalance between M1-like and M2-like macrophages is considered one of the causes of ARDs. The study of a key pathogenetic factor in the development of autoimmune and atherosclerotic inflammation-activated monocyte/macrophages will deepen the knowledge of chronic inflammation pathogenesis. 相似文献
313.
Andrea Stoccoro Filippo Baldacci Roberto Ceravolo Linda Giampietri Gloria Tognoni Gabriele Siciliano Lucia Migliore Fabio Copped 《International journal of molecular sciences》2022,23(10)
Methylation levels of the mitochondrial displacement loop (D-loop) region have been reported to be altered in the brain and blood of Alzheimer’s disease (AD) patients. Moreover, a dynamic D-loop methylation pattern was observed in the brain of transgenic AD mice along with disease progression. However, investigations on the blood cells of AD patients in the prodromal phases of the disease have not been performed so far. The aim of this study was to analyze D-loop methylation levels by means of the MS-HRM technique in the peripheral blood cells of 14 mild cognitive impairment (MCI) patients, 18 early stage AD patients, 70 advanced stage AD patients, and 105 healthy control subjects. We found higher D-loop methylation levels in MCI patients than in control subjects and AD patients. Moreover, higher D-loop methylation levels were observed in control subjects than in AD patients in advanced stages of the disease, but not in those at early stages. The present pilot study shows that peripheral D-loop methylation levels differ in patients at different stages of AD pathology, suggesting that further studies deserve to be performed in order to validate the usefulness of D-loop methylation analysis as a peripheral biomarker for the early detection of AD. 相似文献
314.
Daria Baranowska Tomasz Kdzierski Magorzata Aleksandrzak Ewa Mijowska Beata Zieliska 《International journal of molecular sciences》2021,22(23)
In this contribution, the effect of hydrogenation conditions atmosphere (temperature and time) on physicochemical properties and photocatalytic efficiency of graphitic carbon nitride (g-C3N4, gCN) was studied in great details. The changes in the morphology, chemical structure, optical and electrochemical properties were carefully investigated. Interestingly, the as-modified samples exhibited boosted photocatalytic degradation of Rhodamine B (RhB) with the assistance of visible light irradiation. Among modified gCN, the sample annealed at 500 °C for 4 h (500-4) in H2 atmosphere exhibited the highest photocatalytic activity—1.76 times higher compared to pristine gCN. Additionally, this sample presented high stability and durability after four cycles. It was noticed that treating gCN with hydrogen at elevated temperatures caused the creation of nitrogen vacancies on gCN surfaces acting as highly active sites enhancing the specific surface area and improving the mobility of photogenerated charge carriers leading to accelerating the photocatalytic activity. Therefore, it is believed that detailed optimization of thermal treatment in a hydrogen atmosphere is a facile approach to boost the photoactivity of gCN. 相似文献
315.
Alena Paleskava Elena M. Maksimova Daria S. Vinogradova Pavel S. Kasatsky Stanislav V. Kirillov Andrey L. Konevega 《International journal of molecular sciences》2021,22(17)
The growth of the polypeptide chain occurs due to the fast and coordinated work of the ribosome and protein elongation factors, EF-Tu and EF-G. However, the exact contribution of each of these components in the overall balance of translation kinetics remains not fully understood. We created an in vitro translation system Escherichia coli replacing either elongation factor with heterologous thermophilic protein from Thermus thermophilus. The rates of the A-site binding and decoding reactions decreased an order of magnitude in the presence of thermophilic EF-Tu, indicating that the kinetics of aminoacyl-tRNA delivery depends on the properties of the elongation factor. On the contrary, thermophilic EF-G demonstrated the same translocation kinetics as a mesophilic protein. Effects of translocation inhibitors (spectinomycin, hygromycin B, viomycin and streptomycin) were also similar for both proteins. Thus, the process of translocation largely relies on the interaction of tRNAs and the ribosome and can be efficiently catalysed by thermophilic EF-G even at suboptimal temperatures. 相似文献
316.
317.
The aim was to investigate the physicochemical, microbiological and sensory properties of Pitina, a typical fermented meat product and evaluate the effect of two levels of pork lard content (Low Fat, LF, 10% vs. High Fat, HF, 30%) on its attributes. HF attained lower pH than LF Pitina, which reached lower water activity. LAB comprised the major flora with substantial counts of micrococci, enterococci and mould and yeast. Gram negative Enterobacteria were recovered as coliforms and faecal coliforms. Listeria monocytogenes was also isolated. The lard level influenced the count of micrococci and some sensory attributes. LF attained higher scores for both hardness and cohesiveness and differed from HF in having a more marked odour of ewe and smoke and sweeter taste. HF had a more pronounced odour and taste of garlic and mould than LF. 相似文献
318.
Polina V. Zhdanova Alexander A. Chernonosov Daria V. Prokhorova Grigory A. Stepanov Lyubov Yu. Kanazhevskaya Vladimir V. Koval 《International journal of molecular sciences》2022,23(3)
The Cas9 endonuclease is an essential component of the CRISPR–Cas-based genome editing tools. The attainment of high specificity and efficiency of Cas9 during targetted DNA cleavage is the main problem that limits the clinical application of the CRISPR–Cas9 system. A deep understanding of the Cas9 mechanism and its structural-functional relationships is required to develop strategies for precise gene editing. Here, we present the first attempt to describe the solution structure of Cas9 from S. pyogenes using hydrogen-deuterium exchange mass spectrometry (HDX-MS) coupled to molecular dynamics simulations. HDX data revealed multiple protein regions with deuterium uptake levels varying from low to high. By analysing the difference in relative deuterium uptake by apoCas9 and its complex with sgRNA, we identified peptides involved in the complex formation and possible changes in the protein conformation. The REC3 domain was shown to undergo the most prominent conformational change upon enzyme-RNA interactions. Detection of the HDX in two forms of the enzyme provided detailed information about changes in the Cas9 structure induced by sgRNA binding and quantified the extent of the changes. The study demonstrates the practical utility of HDX-MS for the elucidation of mechanistic aspects of Cas9 functioning. 相似文献
319.
Elena V. Svirshchevskaya Nina V. Sharonova Rimma A. Poltavtseva Mariya V. Konovalova Anton E. Efimov Anton A. Popov Svetlana V. Sizova Daria O. Solovyeva Ivan V. Bogdanov Vladimir A. Oleinikov 《International journal of molecular sciences》2022,23(4)
Multiple studies have demonstrated that various nanoparticles (NPs) stimulate osteogenic differentiation of mesenchymal stem cells (MSCs) and inhibit adipogenic ones. The mechanisms of these effects are not determined. The aim of this paper was to estimate Wharton’s Jelly MSCs phenotype and humoral factor production during tri-lineage differentiation per se and in the presence of silicon–gold NPs. Silicon (SiNPs), gold (AuNPs), and 10% Au-doped Si nanoparticles (SiAuNPs) were synthesized by laser ablation, characterized, and studied in MSC cultures before and during differentiation. Humoral factor production (n = 41) was analyzed by Luminex technology. NPs were nontoxic, did not induce ROS production, and stimulated G-CSF, GM-CSF, VEGF, CXCL1 (GRO) production in four day MSC cultures. During MSC differentiation, all NPs stimulated CD13 and CD90 expression in osteogenic cultures. MSC differentiation resulted in a decrease in multiple humoral factor production to day 14 of incubation. NPs did not significantly affect the production in chondrogenic cultures and stimulated it in both osteogenic and adipogenic ones. The major difference in the protein production between osteogenic and adipogenic MSC cultures in the presence of NPs was VEGF level, which was unaffected in osteogenic cells and 4–9 times increased in adipogenic ones. The effects of NPs decreased in a row AuNPs > SiAuNPs > SiNPs. Taken collectively, high expression of CD13 and CD90 by MSCs and critical level of VEGF production can, at least, partially explain the stimulatory effect of NPs on MSC osteogenic differentiation. 相似文献
320.
Anna Lebedeva Ivan Molodtsov Alexandra Anisimova Anastasia Berestovskaya Oleg Dukhin Antonina Elizarova Wendy Fitzgerald Darya Fomina Kseniya Glebova Oxana Ivanova Anna Kalinskaya Anastasia Lebedeva Maryana Lysenko Elena Maryukhnich Elena Misyurina Denis Protsenko Alexander Rosin Olga Sapozhnikova Denis Sokorev Alexander Shpektor Daria Vorobyeva Elena Vasilieva Leonid Margolis 《International journal of molecular sciences》2022,23(14)
Coronavirus disease 2019 (COVID-19) is characterized by immune activation in response to viral spread, in severe cases leading to the development of cytokine storm syndrome (CSS) and increased mortality. Despite its importance in prognosis, the pathophysiological mechanisms of CSS in COVID-19 remain to be defined. Towards this goal, we analyzed cytokine profiles and their interrelation in regard to anti-cytokine treatment with tocilizumab in 98 hospitalized patients with COVID-19. We performed a multiplex measurement of 41 circulating cytokines in the plasma of patients on admission and 3–5 days after, during the follow-up. Then we analyzed the patient groups separated in two ways: according to the clusterization of their blood cytokines and based on the administration of tocilizumab therapy. Patients with and without CSS formed distinct clusters according to their cytokine concentration changes. However, the tocilizumab therapy, administered based on the standard clinical and laboratory criteria, did not fully correspond to those clusters of CSS. Furthermore, among all cytokines, IL-6, IL-1RA, IL-10, and G-CSF demonstrated the most prominent differences between patients with and without clinical endpoints, while only IL-1RA was prognostically significant in both groups of patients with and without tocilizumab therapy, decreasing in the former and increasing in the latter during the follow-up period. Thus, CSS in COVID-19, characterized by a correlated release of multiple cytokines, does not fully correspond to the standard parameters of disease severity. Analysis of the cytokine signature, including the IL-1RA level in addition to standard clinical and laboratory parameters may be useful to define the onset of a cytokine storm in COVID-19 as well as the indications for anti-cytokine therapy. 相似文献