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排序方式: 共有53条查询结果,搜索用时 15 毫秒
1.
The number of clinical trials evaluating adipose-derived mesenchymal stem cells (AD-MSCs), platelet-rich plasma (PRP), and biomaterials efficacy in regenerative plastic surgery has exponentially increased during the last ten years. AD-MSCs are easily accessible from various fat depots and show intrinsic plasticity in giving rise to cell types involved in wound healing and angiogenesis. AD-MSCs have been used in the treatment of soft tissue defects and chronic wounds, employed in conjunction with a fat grafting technique or with dermal substitute scaffolds and platelet-rich plasma. In this systematic review, an overview of the current knowledge on this topic has been provided, based on existing studies and the authors’ experience. A multistep search of the PubMed, MEDLINE, Embase, PreMEDLINE, Ebase, CINAHL, PsycINFO, Clinicaltrials.gov, Scopus database, and Cochrane databases has been performed to identify papers on AD-MSCs, PRP, and biomaterials used in soft tissue defects and chronic wounds. Of the 2136 articles initially identified, 422 articles focusing on regenerative strategies in wound healing were selected and, consequently, only 278 articles apparently related to AD-MSC, PRP, and biomaterials were initially assessed for eligibility. Of these, 85 articles were excluded as pre-clinical, experimental, and in vitro studies. For the above-mentioned reasons, 193 articles were selected; of this amount, 121 letters, expert opinions, commentary, and editorials were removed. The remaining 72 articles, strictly regarding the use of AD-MSCs, PRP, and biomaterials in chronic skin wounds and soft tissue defects, were analyzed. The studies included had to match predetermined criteria according to the patients, intervention, comparator, outcomes, and study design (PICOS) approach. The information analyzed highlights the safety and efficacy of AD-MSCs, PRP, and biomaterials on soft tissue defects and chronic wounds, without major side effects.  相似文献   
2.
根据河南油田目前存在的情况,开发了一种井下油水分离系统的双级水力旋流样机.利用人工神经网络(Artificial NeuralNetworks,ANN)建立起井下双级水力旋流器的数学模型,通过实验室内柴油以及河南油田实际油样测试,根据前后的分析比较来评估该人工神经网络模型的可靠性和有效性.经过最终实验分析,在并下可以实现两级串联油水分离,当流量控制在6m3/h以上,同时入口油滴粒径大于80μm时,分离器的分离效率最好,可以达到99.5%以上.室内实验分离后水中含油浓度小于50PPm,现场试验小于200PPm,远低于国外室内试验的400PPm指标,测量数据可靠,为其应用于实际生产提供了理论分析基础.  相似文献   
3.
We have used comparative sequence analysis to identify an intein-like sequence (protein splicing element) present in Cryptococcus neoformans, a fungal pathogen of humans. The sequence encoding this element is present in the C. neoformans PRP8 gene, as an in-frame insertion relative to the PRP8 genes of other organisms. It contains sequences similar to those of the protein-splicing domains of two previously described yeast inteins (in Saccharomyces cerevisiae and Candida tropicalis), although it lacks any recognizable internal endonuclease domain. The Cryptococcus neoformans intein (Cne PRP8) is only the second to be found in a eukaryote nuclear genome; the previously described yeast inteins occur at the same site in the VMA gene homologues of S. cerevisiae and C. tropicalis. The host gene of the Cryptococcus intein, PRP8, encodes a highly conserved mRNA splicing protein found as part of the spliceosome. The Cne PRP8 intein may be a useful drug target in addressing the cryptococcal infections so prevalent in AIDS patients.  相似文献   
4.
介绍了IEC62439标准中的几种典型的网络冗余技术,包括跨网冗余协议(CRP)、分布冗余协议(DRP)、媒介冗余协议(MRP)、信标冗余协议(BRP)、并行冗余协议(PRP)和高可用性无缝冗余协议(HSR).CRP支持单网和双网冗余,通过2个端口跨接到1个或2个独立的网络中实现冗余.DRP是基于环网拓扑的冗余模式,在...  相似文献   
5.
Pre-mRNA processing factor 4B (PRP4) has previously been shown to induce epithelial-mesenchymal transition (EMT) and drug resistance in cancer cell lines. As melanin plays an important photoprotective role in the risk of sun-induced skin cancers, we have investigated whether PRP4 can induce drug resistance and regulate melanin biosynthesis in a murine melanoma (B16F10) cell line. Cells were incubated with a crucial melanogenesis stimulator, alpha-melanocyte-stimulating hormone, followed by transfection with PRP4. This resulted in the inhibition of the production of melanin via the downregulation of adenylyl cyclase-cyclic adenosine 3′,5′-monophosphate (AC)–(cAMP)–tyrosinase synthesis signaling pathway. Inhibition of melanin production by PRP4 leads to the promotion of carcinogenesis and induced drug resistance in B16F10 cells. Additionally, PRP4 overexpression upregulated the expression of β-arrestin 1 and desensitized the extracellular calcium-sensing receptor (CaSR), which in turn, inhibited the influx of extracellular Ca2+ ions. The decreased influx of Ca2+ was confirmed by a decreased expression level of calmodulin. We have demonstrated that transient receptor potential cation channel subfamily C member 1 was involved in the influx of CaSR-induced Ca2+ via a decreasing level of its expression. Furthermore, PRP4 overexpression downregulated the expression of AC, decreased the synthesis of cAMP, and modulated the actin cytoskeleton by inhibiting the expression of Ras homolog family member A (RhoA). Our investigation suggests that PRP4 inhibits the production of melanin in B16F10 cells, blocks the influx of Ca2+ through desensitization of CaSR, and modulates the actin cytoskeleton through downregulating the AC–cAMP pathway; taken together, these observations collectively lead to the promotion of skin carcinogenesis.  相似文献   
6.
共轭梯度法是求解无约束非线性规划问题的一种重要方法.针对的几种计算公式。通过几个典型计算实例,对精确一维搜索下所述几种熊的几种计算公式所决定的算法的收敛效果进行比较,分析了它们的数值计算过程、收敛速度及全局收敛性的优劣.  相似文献   
7.
Although the role of platelet-rich plasma (PRP) in tissue regeneration has been confirmed in many studies, the mechanism of this process is still not fully understood. Human keratinocytes (HaCaT) cells were used as an experimental model for studies on the effects of PRP on cell proliferation, migration, collagen biosynthesis, prolidase activity, and its expression and anabolic signaling. The activation of epidermal growth factor receptor (EGFR), β1-integrin, and insulin-like growth factor-1 receptor (IGF-1R) by PRP were investigated by western blot and immunocytochemistry. It has been found that PRP induced keratinocytes migration and proliferation through activation of cell cycle progression and EGFR downstream signaling. Similar biological effects were achieved by an addition to the culture medium of prolidase (PEPD), a ligand of EGFR (PRP is a rich source of PEPD–2 ng/mL). PRP-dependent stimulation of collagen biosynthesis was accompanied by an increase in the expression of NF-κβ, IGF-1R-downstream signaling proteins, and PEPD activity. The data suggest that PRP activates a complex of growth factors and adhesion receptors that stimulate cell proliferation, migration, and collagen biosynthesis. PRP induces PEPD-dependent human keratinocyte proliferation through activation of the EGFR receptor. Our study provides a novel mechanism of PRP-dependent wound healing.  相似文献   
8.
为了解决当前智能变电站自动化系统内网络冗余存在的问题,提出了一种变电站内新型网络冗余的设备(双网冗余接口盒及双网冗余接口卡)软硬件实现方法,将变电站内部保护测控等装置通过双网冗余接口设备接入符合IEC62439-3规范的PRP/HSR网络实现新型双网冗余。采用FPGA+CPU的硬件构架,通过利用在FPGA设计出以太网通信控制MAC模块、PRP/HSR模块、存储控制模块、多路报文转发控制模块协同完成变电站系统内以太网报文冗余处理。试验证明,所研制的冗余设备满足电力系统保护装置对于速动性的要求,在智能变电站自动化系统内具有较好的实用性。  相似文献   
9.
We report the sequence of an 18,002 bp DNA fragment from the right arm of Saccharomyces cerevisiae chromosome XI. This segment contains nine complete open reading frames (ORFs), YKR401 to YKR409, and part of another ORF, YKR400, covering altogether 87·2% of the entire sequence. One of them, YKR400, encodes an NAD-dependent 5,10-methylene-tetrahydrofolate dehydrogenase. YKR404, YKR405 and YKR406 correspond to the previously characterized HBS1, MRP-L20 and PRP16 genes, coding for a translation elongation factor, a mitochondrial ribosomal protein and an ATP-binding protein, respectively. The putative product of YKR407 contains the zinc-binding region signature of neutral zinc metallopeptidases. The five other ORFs do not show significant homology to any known protein. The sequence data reported here have been assigned EMBL accession number Z27116.  相似文献   
10.
基于并行冗余协议的高可靠性过程总线通信研究   总被引:2,自引:0,他引:2  
为确保采样测量值及跳闸命令在过程总线的无损传输,采用双网并行冗余协议(PRP)构建高可靠性过程总线通信系统。分析了基于PRP协议的变压器差动保护过程总线构架及其运行机制。给出了基于采样值报文传输率的网络链路故障定位时间计算方法。根据分布式继电保护功能特征,构建了4种典型保护结构及其可靠性框图,考虑到冗余系统的最小割集相容事件问题,采用最小割集直接不交化法计算量大,引入了简化最小割集补偿算法求解系统可靠度,分析、论证了基于PRP过程总线方案的高可靠性应用优势。  相似文献   
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