Stem cells for regenerative medicine purposes offer therapeutic benefits, but disadvantages are still ill defined. The benefit of stem cells may be attributed to their secretion of growth factors (GFs), cytokines (CKs), and extracellular vesicles (EVs), including exosomes. We present a novel cell-free stem cell-derived extract (CCM), formulated from human progenitor endothelial stem cells (hPESCs), characterized for biologically active factors using ELISA, nanoparticle tracking analysis and single particle interferometric reflectance imaging sensing. The effect on fibroblast proliferation and ability to induce stem cell migration was analyzed using Alamar Blue proliferation and Transwell migration assays, respectively. GFs including IGFBP 1, 2, 3, and 6, insulin, growth hormone, PDGF-AA, TGF-α, TGF-β1, VEGF, and the anti-inflammatory cytokine, IL-1RA were detected. Membrane enclosed particles within exosome size range and expressing exosome tetraspanins CD81 and CD9 were identified. CCM significantly increased cell proliferation and induced stem cell migration. Analysis of CCM revealed presence of GFs, CKs, and EVs, including exosomes. The presence of multiple factors including exosomes within one formulation, the ability to promote cell proliferation and induce stem cell migration may reduce inflammation and pain, and augment tissue repair. 相似文献
In this work, the pentalithium ferrite was synthetized by solid-state method, and it was characterized by XRD and N2 adsorption–desorption techniques. Then, H2 production was obtained through a catalytic conversion process; chemical looping partial oxidation (CLPO) of methane using Li5FeO4 as multifunctional material. The catalytic decomposition of methane is an easy way to obtain clean energy, such as hydrogen, but in this process carbon deposition is also possible. The results showed that this material has the ability to convert methane to hydrogen, but it is also capable to donate oxygen atoms from its crystalline network, producing carbon monoxide and/or carbon dioxide, limiting the carbon deposition on the ceramic surface. In addition, it was demonstrated that this lithium-based ceramic produces hydrogen over a wide temperature range (550–900 °C), with a stable hydrogen production for 3 h at 825 °C. Furthermore, it was possible to achieve a cyclic test of methane decomposition with a pre-oxidation process between each cycle obtaining an outstanding increase in hydrogen production from 10% in cycle 1 to ~?100% in the cycle 10. This previous stage not only induces an increase in the decomposition of methane, but also avoids carbon deposition accompanied by the production of both COX compounds. Finally, it must be mentioned that Li5FeO4 is capable to chemisorb both carbon oxides produced, promoting high purity hydrogen production.
An untapped source of amorphous SiO2, industrially generated Indian biomass ash (SA)—90% amorphous, with composition of ~60% SiO2 and ~20% unburnt carbon—can be used to produce cementitious and alkali-activated binders. This study reports dissolution of amorphous Si from SA in 0.5 mol/L and 1 mol/L aqueous NaOH, with and without added Ca(OH)2, at SA:Ca(OH)2 wt% ratios of 100:0, 87.5:12.5, and 82.5:17.5. Monitoring of elemental dissolution and subsequent/simultaneous product uptake by ICP-OES offers an effective process for evaluating utility of industrial wastes in binder-based systems. After 28 days in solution, up to 68% of total Si is dissolved from SA in 1 mol/L NaOH, with values as much as 38% lower in the presence of Ca(OH)2, due to the formation of tobermorite-like C-S-H. FTIR, 29Si MAS-NMR, and XRD are used to characterize solid reaction products and observe reaction progress. Product chemistries calculated from ICP-OES results and verified by selective dissolution in EDTA/NaOH—namely, Ca/Si of 0.6-1 and Na adsorption of 1-2 mmol/g—are found to be consistent with those indicated by aforementioned techniques. This indicates the efficacy of ICP-OES in estimating product chemistry via such a methodology. 相似文献
In this work we use Impedance Spectroscopy (IS) to study lead‐free ceramics of perovskite structure (Bi1/2Na1/2TiO3)0.925(BaTiO3)0.075 with Mn doping of 0, 0.2, 1.0, and 2.0 at.%. We compare our IS results with permittivity results, using dielectric to resistivity transformation equations which allow us to display results either as permittivity or as resistivity. We observe ionic conductivity dominating at lower temperatures, giving way to electronic conductivity at higher temperatures. The permittivity shows deviations from Curie‐Weiss behavior characteristic of relaxor ferroelectrics. The 0.2% Mn samples show the highest ionic resistivity, which will reduce heating for high voltage piezoelectric applications. They also have the highest Curie‐Weiss temperature and Burns temperature. 相似文献
In recent years, considerable attention has been paid to enterprise information systems. This interest is motivated by the need for achieving better integration of new technologies (hardware and software) with the business processes of an organization. Business processes have become more and more dependent on technologies because technology has a direct impact on business processes, changing the way they are performed and thus also affecting the way analysts design the software system. However, at the present time, there are still some gaps between the definition of business processes and the technologies used in the organization. In practice, organizations have carried out their business processes using different technologies; however, it is sometimes not possible to determine how technologies are useful in achieving current business goals. This is because business models do not explicitly consider the technologies in the organizational requirements. The goal of this paper is to present a systematic process for integrating business processes and technologies at the conceptual level. To validate our approach, we present a case study that describes the processes of the inventory management department of a public research center. 相似文献
For some years now, the Nederlandse Taalunie (Dutch Language Union) has been active in promoting the development of human
language technology (HLT) applications for speakers of Dutch with communicative disabilities. The reason is that HLT products
and services may enable them to improve their communication skills and verbal autonomy. We sought to identify a minimum common
set of HLT resources that is required to develop tools for a wide range of communication disabilities. In order to reach this
goal, we investigated the specific needs of communicatively disabled people and related these needs to the underlying HLT
software components. By analysing the availability and quality of these essential HLT resources, we were able to identify
which of the crucial elements need further research and development to become usable for developing applications for communicatively
disabled speakers of Dutch. The results obtained in the current survey can be used to inform policy institutions on how they
can stimulate the development of HLT resources for this target group. In the current survey results were obtained for Dutch,
but a similar approach can also be applied to other languages. 相似文献
We compare the recently proposed Discriminative Restricted Boltzmann Machine (DRBM) to the classical Support Vector Machine (SVM) on a challenging classification task consisting in identifying weapon classes from audio signals. The three weapon classes considered in this work (mortar, rocket, and rocket‐propelled grenade), are difficult to reliably classify with standard techniques because they tend to have similar acoustic signatures. In addition, specificities of the data available in this study make it challenging to rigorously compare classifiers, and we address methodological issues arising from this situation. Experiments show good classification accuracy that could make these techniques suitable for fielding on autonomous devices. DRBMs appear to yield better accuracy than SVMs, and are less sensitive to the choice of signal preprocessing and model hyperparameters. This last property is especially appealing in such a task where the lack of data makes model validation difficult. 相似文献