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1.
The potential use of stem cell-based therapies for the repair and regeneration of various tissues and organs is a major goal in repair medicine. Stem cells are classified by their potential to differentiate into functional cells. Compared with other sources, adipose-derived stem cells (ADSCs) have the advantage of being abundant and easy to obtain. ADSCs are considered to be tools for replacing, repairing, and regenerating dead or damaged cells. The capacity of ADSCs to maintain their properties depends on the balance of complex signals in their microenvironment. Their properties and the associated outcomes are in part regulated by reactive oxygen species, which mediate the oxidation-reduction state of cells as a secondary messenger. ADSC therapy has demonstrated beneficial effects, suggesting that secreted factors may provide protection. There is evidence that ADSCs secrete a number of cytokines, growth factors, and antioxidant factors into their microenvironment, thus regulating intracellular signaling pathways in neighboring cells. In this review, we introduce the roles of ADSCs in the protection of cells by modulating inflammation and immunity, and we develop their potential therapeutic properties.  相似文献   
2.
Protection of Metals and Physical Chemistry of Surfaces - Corrosion inhibition propriety of (2E)-3-phenylprop-2-enal, known as trans-cinnamaldehyde (TCA) for mild steel in 1 M HCl medium was...  相似文献   
3.
Second generation biofuels are produced in the bioliq® process at the Karlsruhe Institute of Technology via gasification of pyrolysis oil and synthesis of gasoline from the emerging synthesis gas. An alternative strategy is the direct upgrading of the pyrolysis oil by hydrodeoxygenation (HDO). The present study reports on the HDO of guaiacol as one of the phenolic compounds strongly abundant in such mixtures. Special focus was laid on the solvent influence using Pt‐based catalysts. Higher HDO ability was seen using nonpolar solvents and acidic supports. Characterization of the catalysts before and after the test showed that the solvent did not only influence the reactivity, but also the catalyst stability.  相似文献   
4.
Echinocandins are cyclic nonribosomal hexapeptides based mostly on nonproteinogenic amino acids and displaying strong antifungal activity. Despite previous studies on their biosynthesis by fungi, the origin of three amino acids, trans‐4‐ and trans‐3‐hydroxyproline, as well as trans‐3‐hydroxy‐4‐methylproline, is still unknown. Here we describe the identification, overexpression, and characterization of GloF, the first eukaryotic α‐ketoglutarate/FeII‐dependent proline hydroxylase from the pneumocandin biosynthesis cluster of the fungus Glarea lozoyensis ATCC 74030. In in vitro transformations with L ‐proline, GloF generates trans‐4‐ and trans‐3‐hydroxyproline simultaneously in a ratio of 8:1; the latter reaction was previously unknown for proline hydroxylase catalysis. trans‐4‐Methyl‐L ‐proline is converted into the corresponding trans‐3‐hydroxyproline. All three hydroxyprolines required for the biosynthesis of the echinocandins pneumocandins A0 and B0 in G. lozoyensis are thus provided by GloF. Sequence analyses revealed that GloF is not related to bacterial proline hydroxylases, and none of the putative proteins with high sequence similarity in the databases has been characterized so far.  相似文献   
5.
Hydroxyapatite (HA) coating with nanoparticles like nanorice is fabricated on chemically pretreated titanium (Ti) surface, through an electrochemical deposition approach, for biomaterial applications. The Ti surface was chemically patterned with anatase TiO2 nanofibers. These nanofibers were prepared by in situ oxidation of Ti foils in a concentrated solution of H2O2 and NaOH, followed by proton exchange and calcinations. Afterward, TiO2 nanofibers on Ti substrate were coated with HA nanoparticles like nanorice. The obtained samples were annealed at high temperature to produce inter diffusion between TiO2 and HA layers. The resultant layers were characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), X-ray Diffraction (XRD), Infrared Spectroscopy (FTIR), corrosion tests in SBF solution, and Electron Probe Micro Analysis (EPMA). It was found that only Ti from the titanium substrate diffuses into the HA coating and a good corrosion resistance in simulated body fluid was obtained.  相似文献   
6.
OBJECTIVE: Little attention has been paid to the occurrence of aortic regurgitation after complete repair in patients with pulmonary atresia and ventricular septal defect or tetralogy of Fallot. To highlight the development of aortic regurgitation or aortic root dilation severe enough to necessitate aortic valve replacement with or without aortic aneurysmorrhaphy or aortic root replacement, we retrospectively reviewed the records of patients who underwent aortic valve operation at our institution subsequent to repair of pulmonary atresia and ventricular septal defect or tetralogy of Fallot. METHODS: We searched the Mayo Clinic database for patients with pulmonary atresia and ventricular septal defect or tetralogy of Fallot who subsequently had aortic valve or aortic root operations. The degree of aortic regurgitation before operation was noted. Aortic sinus and root dimensions were measured. RESULTS: Sixteen patients underwent complete repair at a median age of 17 years, followed by an aortic operation a median of 13.5 years later. All 16 patients had dilated aortic sinuses at the time of the aortic valve operation. These 16 patients had aortic valve replacement: 11 with mechanical prostheses and 5 with bioprostheses. Five of the 16 also had reduction of aortic dilation by lateral aneurysmorrhaphy, and 1 had graft replacement of the ascending aorta. Five patients had associated conditions (evidence of valvular damage, recurrent ventricular septal defect, or history of endocarditis) discovered at the aortic valve operation that have been reported to be related to the development of aortic regurgitation. The remaining 11 patients had progressive aortic regurgitation despite complete, uncomplicated repair. CONCLUSIONS: Progressive aortic regurgitation and aortic root dilation can occur despite complete repair of pulmonary atresia and ventricular septal defect or tetralogy of Fallot.  相似文献   
7.
The efficiency of eucalyptus bark as a low cost sorbent for removing cadmium ions from aqueous solution has been investigated in batch mode. The equilibrium data could be well described by the Langmuir isotherm but a worse fit was obtained by the Freundlich model. The five linearized forms of the Langmuir equation as well as the non-linear curve fitting analysis method were discussed. Results show that the non-linear method may be a better way to obtain the Langmuir parameters. Maximum cadmium uptake obtained at a temperature of 20 degrees C was 14.53mgg(-1). The influence of temperature on the sorption isotherms of cadmium has been also studied. The monolayer sorption capacity increased from 14.53 to 16.47 when the temperature was raised from 20 to 50 degrees C. The DeltaG degrees values were negative, which indicates that the sorption was spontaneous in nature. The effect of experimental parameters such as contact time, cadmium initial concentration, sorbent dose, temperature, solution initial pH, agitation speed, and ionic strength on the sorption kinetics of cadmium was investigated. Pseudo-second-order model was evaluated using the six linear forms as well as the non-linear curve fitting analysis method. Modeling of kinetic results shows that sorption process is best described by the pseudo-second-order model using the non-linear method. The pseudo-second-order model parameters were function of the initial concentration, the sorbent dose, the solution pH, the agitation speed, the temperature, and the ionic strength.  相似文献   
8.
OBJECTIVE: The authors report an exceptional site of tuberculous osteo-articular infection which must be diagnosed before the destructive stage. OBSERVATIONS: Case 1 : a 21 years old woman presented an inflammatory pubic pain after a trauma with weight loss of 4 kgs in 3 weeks. She presented also 2 satellite inguinal nodes. Erythrocyte sedimentation rate (ESR) was elevated, X-rays showed an important osteolysis of the left ischio-pubic rami, tuberculous skin test (TST) was positive, mycobacterium tuberculosis (MT) could not be found neither in sputtum nor in urine but the node biopsy showed the specific features of tuberculosis. Evolution under a 6 months antibiotic treatment was good. Case 2 : a 19 years old woman, with history of tuberculous contagion, presented in April 1996 cervical nodes and a month later inflammatory pubic and knee pain with weight loss and vesperal sudation. ESR was elevated, TST was phlyctenular, MT searching and HIV serology were negative. X rays showed irregular osteolysis of the pubic symphysis. Scintigraphy showed an increased fixation of pubis and left knee. Cervical nodes biopsy diagnosed tuberculosis. Evolution was good under a 6 months antibiotic treatment. DISCUSSION: Many factors can favorize the development of a pubic tuberculosis and are similar for all forms of tuberculous osteo-articular infection (trauma and contagion in our cases). Radiological features, characterized by a slow evolution, are note specific. Diagnostic confirmation must be bacteriologic or pathologic, and if possible far from the pubic foci. Any traumatic medical procedure has to be avoided because of painful outcome and local risk. Evolution under specific treatment, even of short course (6 months), is sufficient for a good outcome. CONCLUSION: One must think to pubic tuberculous osteo-arthritis in any pubic pain even if it is post-traumatic especially, in endemic countries of tuberculosis.  相似文献   
9.
The surface and self-aggregation properties in water of a new series of amphiphilic homologues, bis-benzimidazolone derivatives of d-glucose, were investigated. Parameters such as the maximal surface excess concentration, minimal area per molecule at the interface, and critical micelle concentration (CMC) were found to be significantly dependent on the hydrophobic alkyl chain length. The synthesized compounds form micelles at remarkably low concentrations, and CMCs derived from surface tension measurements show a minimum as a function of the alkyl chain length; this unusual trend can be attributed to the formation of submicellar aggregates in compounds with long alkyl chains, as evidenced from fluorescence probe spectroscopy data. At high surfactant concentrations, lyotropic liquid crystalline phases with hexagonal structure are formed. Small angle X-ray scattering measurements indicate that the characteristic nanoscopic lengths increase with water swelling and alkyl chain length.  相似文献   
10.
Xanthosiderohistiocytosis is a rare non-Langerhans histiocytosis (4 reported cases). The clinical characteristics include diffuse, sometimes deep, dark-brown infiltrations of the skin. Histological examination reveals abundant deposits of haemosiderin within the histiocyte proliferation. This entity is a clinical form of Montgomery's disease (xanthoma disseminatum) which has been reported in over 100 cases. Our case of disseminated xanthosiderohistiocytosis was particular because it involved the heart and was associated with a monoclonal gammapathy. Five cases have been reported associating xanthoma disseminatum and monoclonal gammapathy, including one case of xanthosiderohistiocytosis. In our case, rapidly increasing levels of monoclonal immunoglobulin suggested an evolution towards a myeloma. A monoclonal gammapathy should be looked for and monitored in cases of xanthosiderohistiocytosis, and more generally xanthoma disseminatum because of the risk of developing lymphoma or myeloma.  相似文献   
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