全文获取类型
收费全文 | 1071篇 |
免费 | 97篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 6篇 |
综合类 | 3篇 |
化学工业 | 531篇 |
金属工艺 | 7篇 |
机械仪表 | 20篇 |
建筑科学 | 29篇 |
能源动力 | 28篇 |
轻工业 | 149篇 |
水利工程 | 3篇 |
石油天然气 | 1篇 |
无线电 | 80篇 |
一般工业技术 | 179篇 |
冶金工业 | 40篇 |
原子能技术 | 1篇 |
自动化技术 | 92篇 |
出版年
2024年 | 2篇 |
2023年 | 10篇 |
2022年 | 124篇 |
2021年 | 178篇 |
2020年 | 38篇 |
2019年 | 36篇 |
2018年 | 49篇 |
2017年 | 29篇 |
2016年 | 55篇 |
2015年 | 40篇 |
2014年 | 52篇 |
2013年 | 75篇 |
2012年 | 57篇 |
2011年 | 89篇 |
2010年 | 49篇 |
2009年 | 42篇 |
2008年 | 37篇 |
2007年 | 33篇 |
2006年 | 30篇 |
2005年 | 28篇 |
2004年 | 20篇 |
2003年 | 13篇 |
2002年 | 11篇 |
2001年 | 8篇 |
2000年 | 3篇 |
1999年 | 11篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 7篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1976年 | 2篇 |
1969年 | 1篇 |
排序方式: 共有1169条查询结果,搜索用时 265 毫秒
951.
Pierluigi Giampaolino Virginia Foreste Claudia Di Filippo Alessandra Gallo Antonio Mercorio Paolo Serafino Francesco Paolo Improda Paolo Verrazzo Giuseppe Zara Cira Buonfantino Maria Borgo Gaetano Riemma Chiara De Angelis Brunella Zizolfi Giuseppe Bifulco Luigi Della Corte 《International journal of molecular sciences》2021,22(4)
Polycystic ovary syndrome (PCOS) is a complex and heterogeneous endocrine disease. The hypothesis that alterations in the microbiome are involved in the genesis of PCOS has been postulated. Aim of this review is to summarize the available literature data about the relationship between microbiome and PCOS. A search on PubMed and Medline databases was performed from inception to November 20Most of evidence has focused on the connection of intestinal bacteria with sex hormones and insulin-resistance: while in the first case, a relationship with hyperandrogenism has been described, although it is still unclear, in the second one, chronic low-grade inflammation by activating the immune system, with increased production of proinflammatory cytokines which interfere with insulin receptor function, causing IR (Insulin Resistance)/hyperinsulinemia has been described, as well as the role of gastrointestinal hormones like Ghrelin and peptide YY (PYY), bile acids, interleukin-22 and Bacteroides vulgatus have been highlighted. The lower genital tract microbiome would be affected by changes in PCOS patients too. The therapeutic opportunities include probiotic, prebiotics and synbiotics, as well as fecal microbiota transplantation and the use of IL-22, to date only in animal models, as a possible future drug. Current evidence has shown the involvement of the gut microbiome in PCOS, seen how humanized mice receiving a fecal transplant from women with PCOS develop ovarian dysfunction, immune changes and insulin resistance and how it is capable of disrupting the secondary bile acid biosynthesis. A future therapeutic approach for PCOS may involve the human administration of IL-22 and bile acid glycodeoxycholic acid. 相似文献
952.
Roberta Pecoraro Antonio Salvaggio Elena M. Scalisi Carmelo Iaria Giovanni Lanteri Chiara Copat Margherita Ferrante Giuseppe Fragal Massimo Zimbone Giuliana Impellizzeri Maria V. Brundo 《Microscopy research and technique》2019,82(8):1297-1301
Although in recent years there has been intensification in the use of nanoparticles (NPs) for the production of many commercial products, few studies have been carried out to assess the risks associated with its use. Among the most used NPs, silver nanoparticles (AgNPs) have a preponderant position as they have various applications. In this study, 40 adult zebrafish were exposed to increasing concentrations of AgNPs (8, 45, and 70 μg/L) for 30 days to evaluate the effects on eyes after chronic exposure to AgNPs with an average diameter of 50 nm. From the morphological and ultrastructural analysis performed, no alteration or lesions of the corneal epithelium were detected. 相似文献
953.
Hamada Elsayed Francesco Carraro Stefano Agnoli Devis Bellucci Valeria Cannillo Letizia Ferroni Chiara Gardin Barbara Zavan Enrico Bernardo 《Journal of the European Ceramic Society》2018,38(15):5200-5207
Calcite-based composite scaffolds have been successfully 3D-printed by direct ink writing, starting from a paste comprising a silicone polymer and calcite (CaCO3) powders. The firing in nitrogen, at 600?°C, after preliminary cross-linking step at 350?°C, determined the transformation of the polymer matrix into a silica-carbon nano-composite, embedding unreacted calcite particles. Compared to previously developed silica-calcite scaffolds, obtained after firing in air, the new composites exhibited a significant strength improvement (up to ~10?MPa, for a total open porosity of 56%). The new formulation did not compromise the in vitro bioactivity and the biocompatibility of the scaffolds, as shown by dissolution studies in SBF and preliminary cell culture tests, with human fibroblasts. Due to the simplicity of the processing and the outstanding mechanical performances, the developed scaffolds are promising candidates for bone tissue engineering applications. 相似文献
954.
955.
956.
Ram Manohar Basnet Daniela Zizioli Alessia Musc Dario Finazzi Sandra Sigala Elisa Rossini Chiara Tobia Jessica Guerra Marco Presta Maurizio Memo 《International journal of molecular sciences》2021,22(9)
In this study, we report the effects of caffeine on angiogenesis in zebrafish embryos both during normal development and after exposure to Fibroblast Growth Factor 2 (FGF2). As markers of angiogenesis, we measured the length and width of intersegmental vessels (ISVs), performed whole-mount in situ hybridization with fli1 and cadh5 vascular markers, and counted the number of interconnecting vessels (ICVs) in sub-intestinal venous plexus (SIVP). In addition, we measured angiogenesis after performing zebrafish yolk membrane (ZFYM) assay with microinjection of fibroblast growth factor 2 (FGF2) and perivitelline tumor xenograft assay with microinjection of tumorigenic FGF2-overexpressing endothelial (FGF2-T-MAE) cells. The results showed that caffeine treatment causes a shortening and thinning of ISVs along with a decreased expression of the vascular marker genes and a decrease in the number of ICVs in the SIVP. Caffeine was also able to block angiogenesis induced by exogenous FGF2 or FGF2-producing cells. Overall, our results are suggestive of the inhibitory effect of caffeine in both direct and indirect angiogenesis. 相似文献
957.
Luca Bini Domitille Schvartz Chiara Carnemolla Roberta Besio Nadia Garibaldi Jean-Charles Sanchez Antonella Forlino Laura Bianchi 《International journal of molecular sciences》2021,22(1)
Osteogenesis imperfecta (OI) is a heritable disorder that mainly affects the skeleton. The inheritance is mostly autosomal dominant and associated to mutations in one of the two genes, COL1A1 and COL1A2, encoding for the type I collagen α chains. According to more than 1500 described mutation sites and to outcome spanning from very mild cases to perinatal-lethality, OI is characterized by a wide genotype/phenotype heterogeneity. In order to identify common affected molecular-pathways and disease biomarkers in OI probands with different mutations and lethal or surviving phenotypes, primary fibroblasts from dominant OI patients, carrying COL1A1 or COL1A2 defects, were investigated by applying a Tandem Mass Tag labeling-Liquid Chromatography-Tandem Mass Spectrometry (TMT LC-MS/MS) proteomics approach and bioinformatic tools for comparative protein-abundance profiling. While no difference in α1 or α2 abundance was detected among lethal (type II) and not-lethal (type III) OI patients, 17 proteins, with key effects on matrix structure and organization, cell signaling, and cell and tissue development and differentiation, were significantly different between type II and type III OI patients. Among them, some non–collagenous extracellular matrix (ECM) proteins (e.g., decorin and fibrillin-1) and proteins modulating cytoskeleton (e.g., nestin and palladin) directly correlate to the severity of the disease. Their defective presence may define proband-failure in balancing aberrances related to mutant collagen. 相似文献
958.
Serena Martire Francesca Montarolo Michela Spadaro Simona Perga Maria Ludovica Sforza Luca Marozio Federica Frezet Stefania Bruno Giulia Chiabotto Maria Chiara Deregibus Giovanni Camussi Giovanni Botta Chiara Benedetto Antonio Bertolotto 《International journal of molecular sciences》2021,22(6)
Pregnancy is a unique situation of physiological immunomodulation, as well as a strong Multiple Sclerosis (MS) disease modulator whose mechanisms are still unclear. Both maternal (decidua) and fetal (trophoblast) placental cells secrete extracellular vesicles (EVs), which are known to mediate cellular communication and modulate the maternal immune response. Their contribution to the MS disease course during pregnancy, however, is unexplored. Here, we provide a first phenotypic and functional characterization of EVs isolated from cultures of term placenta samples of women with MS, differentiating between decidua and trophoblast. In particular, we analyzed the expression profile of 37 surface proteins and tested the functional role of placental EVs on mono-cultures of CD14+ monocytes and co-cultures of CD4+ T and regulatory T (Treg) cells. Results indicated that placental EVs are enriched for surface markers typical of stem/progenitor cells, and that conditioning with EVs from samples of women with MS is associated to a moderate decrease in the expression of proinflammatory cytokines by activated monocytes and in the proliferation rate of activated T cells co-cultured with Tregs. Overall, our findings suggest an immunomodulatory potential of placental EVs from women with MS and set the stage for a promising research field aiming at elucidating their role in MS remission. 相似文献
959.
Anna Chiara Lai Paola Loreti Pierluigi Vellucci 《Mathematics of Control, Signals, and Systems (MCSS)》2016,28(2):15
We study a model for snake-like robots based on the Fibonacci sequence. The present paper includes an investigation of the reachable workspace, a more general analysis of the control system underlying the model, its reachability and local controllability properties. In addition, we establish some fractal properties of the reachable workspace by means the theory of iterated function systems. 相似文献
960.
Tissue Regeneration: A Multifunctional Polymeric Periodontal Membrane with Osteogenic and Antibacterial Characteristics (Adv. Funct. Mater. 3/2018)
下载免费PDF全文
![点击此处可从《Advanced functional materials》网站下载免费的PDF全文](/ch/ext_images/free.gif)