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91.
Seemann L  Stemmer A  Naujoks N 《Nano letters》2007,7(10):3007-3012
This article reports on the directed deposition of carbon nanotubes (CNTs) and fullerenes onto solid surfaces using local electrostatic fields. Arbitrary patterns of local surface charges are created by charge writing with an atomic force microscope. During the subsequent development of the sample in an aqueous suspension containing surfactant-stabilized CNTs or fullerenes, Coulomb attraction guides the positioning and alignment of these particles onto the charge patterns. The surface potential of the charge patterns provides a direct control over the particle attachment. CNTs and fullerenes precisely reproduce the charge patterns, yielding structures with a lateral resolution down to the particle diameter.  相似文献   
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Collagens are the most abundant proteins in vertebrates and constitute the major components of the extracellular matrix. Collagens play an important and multifaceted role in the development and functioning of the nervous system and undergo structural remodeling and quantitative modifications during aging. Here, we investigated the age-dependent regulation of col4a1 and col25a1 in the brain of the short-lived vertebrate Nothobranchius furzeri, a powerful model organism for aging research due to its natural fast-aging process and further characterized typical hallmarks of brain aging in this species. We showed that col4a1 and col25a1 are relatively well conserved during vertebrate evolution, and their expression significantly increases in the brain of N. furzeri upon aging. Noteworthy, we report that both col4a1 and col25a1 are expressed in cells with a neuronal phenotype, unlike what has already been documented in mammalian brain, in which only col25a1 is considered a neuronal marker, whereas col4a1 seems to be expressed only in endothelial cells. Overall, our findings encourage further investigation on the role of col4a1 and col25a1 in the biology of the vertebrate brain as well as the onset of aging and neurodegenerative diseases.  相似文献   
94.
At Tufts University, we have initiated an engineering minor and concentration certificate program in Musical Instrument Engineering (MIE) as an exciting way to introduce and teach principles of mechanical engineering to undergraduate students. The goal of this program is to teach the fundamentals of engineering through the manufacture of musical instruments. As musical instruments are both familiar and complex, they provide non‐threatening and enjoyable focal points for engineering education. This interdisciplinary curriculum combines a variety of learning experiences, including lecturing, experimental analysis, and project development. In this paper we outline the minor and certificate programs, and assess the initial success of the Musical Instrument Engineering program through the response of faculty, administration, and students.  相似文献   
95.
NPY is among the most abundant neuropeptides in vertebrate brain and is primarily involved in the regulation of food intake. The NPY system is also associated with the aging process showing beneficial effects on neuronal survival via autophagy modulation. Here, we explore the age-related regulation of NPY in the brain and foregut of the shortest- and longest-lived fish species, Nothobranchius furzeri and Danio rerio, respectively. These two research models, despite some similarities, display profound biological differences making them attractive vertebrates to elucidate the mechanisms underlying the regulation of neuropeptide synthesis and function. It is noteworthy that in both fish species only Npya has been identified, while in the other teleosts two classes of NPY (Npya and Npyb) have been annotated. Our findings document that in both species: (i) NPY is centrally regulated; (ii) NPY levels increase in the brain during aging; (iii) NPY is localized in the enteroendocrine cells as well as in the myenteric plexus and drastically decreases in old animals. According to our data, the age-related regulation in the gut resembles that described in other vertebrate species while the increased levels in the brain offer the unique possibility to explore the role of NPY in model organisms to develop future experimental and translatable approaches.  相似文献   
96.
There is a lack of in vitro models able to plausibly represent the inflammation microenvironment of knee osteoarthritis (OA). We analyzed the molecules released from OA tissues (synovial membrane, cartilage, infrapatellar fat pad) and investigated whether the stimulation of human synovial fibroblasts (SFs), with synthetic cytokines (IL-1β and TNF-α or IFN-γ) or conditioned media (CM) from OA tissues, influence the SFs’ response, in the sense of pro-inflammatory cytokines, chemokines, growth factors, and degradative enzymes modulation. Human SFs were obtained from OA synovial membranes. SFs and their CM were analyzed for biomarkers, proliferation rate, protein profile and gene expression, before and after stimulation. Real-time PCR and multiplex assays quantified OA-related gene expression and biomolecule production. Unlike other activators, CM from OA synovial membrane (CM-SM), significantly up-regulated all genes of interest (IL-6, IL-8, MMP-1, MMP-3, RANTES, MCP-1, TSG-6, YKL-40) in SFs. Multiplex immunoassay analysis showed that levels of OA-related cytokines (IL-6, IL-8, MCP 1, IL-1Ra), chemokine (RANTES) and growth factor (VEGF), produced by CM-SM stimulated SFs, increased significantly compared to non-stimulated SFs. Molecules released from the SM from OA patients induces OA-like changes in vitro, in specific OA synovial populations (SFs). These findings promote the use and establish a compelling in vitro model that simulates the versatility and complexity of the OA disease. This model, in the future, will allow us to study new cell therapies or test drugs by reducing or avoiding animal models.  相似文献   
97.
Liver fibrosis, depending on the stage of the disease, could lead to organ dysfunction and cirrhosis, and no effective treatment is actually available. Emergent proof supports a link between oxidative stress, liver fibrogenesis and mitochondrial dysfunction as molecular bases of the pathology. A valid approach to protect against the disease would be to replenish the endogenous antioxidants; thus, we investigated the protective mechanisms of the S-acetyl-glutathione (SAG), a glutathione (GSH) prodrug. Preliminary in vitro analyses were conducted on primary hepatic cells. SAG pre-treatment significantly protected against cytotoxicity induced by CCl4. Additionally, CCl4 induced a marked increase in AST and ALT levels, whereas SAG significantly reduced these levels, reaching values found in the control group. For the in vivo analyses, mice were administered twice a week with eight consecutive intraperitoneal injections of 1 mL/kg CCl4 (diluted at 1:10 in olive oil) to induce oxidative imbalance and liver inflammation. SAG (30 mg/kg) was administered orally for 8 weeks. SAG significantly restored SOD activity, GSH levels and GPx activity, while it strongly reduced GSSG levels, lipid peroxidation and H2O2 and ROS levels in the liver. Additionally, CCl4 induced a decrease in anti-oxidants, including Nrf2, HO-1 and NQO-1, which were restored by treatment with SAG. The increased oxidative stress characteristic on liver disfunction causes the impairment of mitophagy and accumulation of dysfunctional and damaged mitochondria. Our results showed the protective effect of SAG administration in restoring mitophagy, as shown by the increased PINK1 and Parkin expressions in livers exposed to CCl4 intoxication. Thus, the SAG administration showed anti-inflammatory effects decreasing pro-inflammatory cytokines TNF-α, IL-6, MCP-1 and IL-1β in both serum and liver, and suppressing the TLR4/NFkB pathway. SAG attenuated reduced fibrosis, collagen deposition, hepatocellular damage and organ dysfunction. In conclusion, our results suggest that SAG administration protects the liver from CCl4 intoxication by restoring the oxidative balance, ameliorating the impairment of mitophagy and leading to reduced inflammation.  相似文献   
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99.
Microgravity produces a variety of physical, chemical, and biological cues leading to an intricate and largely unresolved network of mechanosensitive molecules, transduction pathways, oxidative stress-related responses, and adaptations. The bone loss observed in astronauts and animal models after spaceflight is attributable to alterations in the bone tissue formation that depends on the continuous remodelling through the activities of bone-resorbing osteoclasts of hematopoietic lineage and bone-forming osteoblast of mesenchymal origin. Focusing on osteogenic differentiation, we present the results of the ”SCD - Stem Cells Differentiation” experiment, aiming to determine how human bone marrow stem cells (hBMSCs) react to a prolonged (approx. 2 weeks) exposure to microgravity in terms of growth, and differentiation when treated with a physiological osteo-inducer as 1,25-dihydroxy vitamin D (Vit D3). The experiment was selected by the European Space Agency and transferred to ISS with the Soyuz-TMA- 16M (ISS 42S). It was carefully prepared because experiments performed on ISS remain a uniquely exceptional means of clarifying the microgravitational effects on osteogenesis, often only partially activated and detectable under simulated conditions. Because of the substantial reduction in calcification observed (about 50% inflight vs. on-ground control), we looked at significantly affected pathways in hBMSCs grown in microgravity vs. on-ground controls. Genome-wide expression changes were assessed via microarray and next generation sequencing (NGS) and integrated with exosomal mi-RNA measurements. Multi-scale pathway analysis of the omics datasets revealed evidence of cell cycle arrest, occurring with a number of osteogenic gene markers, but without indications of adipogenesis, senescence and/or apoptosis.  相似文献   
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