In this study, the silanized coal fly ash (CFA) and silanized nano-/micro-glass fiber (nGF) were simultaneously embedded in vinyl ester resin for improvement in both mechanical properties and mode I ...interlaminar fracture toughness of carbon fiber-based composite material. The used CFA particles have thermal power plant origin and were grinded with the help of ball mill to obtain the uniform size. The methacryloxy groups were attached to surface of both ground CFA and pristine nGF via silanization process. The homologous mixtures of S-nGF and S-CFA in vinyl ester resin were obtained with the help of high-speed mechanical stirrer and ultrasonic technique. The sheet molding compound method and hot curing process were applied to fabricate the carbon fiber-filled vinyl ester resin-based composite. Many techniques such as FTIR, EDS, rheological testing, mode I interlaminar fracture toughness, tensile strength and SEM were used to investigate the characteristics of silanized additives, the uncured matrices as well as the carbon fiber-based composite materials. The incorporation of both 0.1 wt% S-nGF and 1 wt% S-CFA into VE resin helps to improve the tensile strength, tensile modulus and the mode I interlaminar fracture toughness (
G
IC
) of carbon fiber-based composites (CFRP) by 61.39%, 39.83% and 48.61%, respectively, when compared with pristine composite material. The fracture toughness surface of modified VE was tougher and rougher as a result of higher fracture toughness, while the pristine VE exhibited the smooth surface.
Purpose
We aimed to describe our robotic-assisted surgery (RAS) techniques and assess the early results of RAS for choledochal cysts in children.
Methods
We conducted a retrospective chart review of ...children who underwent RAS for a congenital choledochal cyst at our institution between February 2013 and August 2016. We analyzed patient characteristics, operative data, and postoperative outcomes.
Results
Thirty-nine patients underwent RAS for a choledochal cyst (female 30). The operation was performed with four robotic ports and one laparoscopic port for the assistant. The Roux loop was fashioned extracorporeally. Twenty patients (51.3%) had a Todani Type I cyst and the others had Type IV. The mean patient age and weight and choledochal cyst diameter at the time of the operation were 40.2 months (range 5–108 months), 13.4 kg (range 6.5–29 kg), and 27.2 mm (range 9–112 mm), respectively. The mean operating time was 192.7 min (range 150–330 min). There were no intraoperative complications; no conversions to laparoscopic or open surgery; and no postoperative complications, including cholangitis, cholelithiasis, or anastomotic stenosis.
Conclusion
Pediatric RAS CC resection is safe and feasible. The robot-assisted technique overcame technical difficulties. However, in pediatric cases, a skilled robotic surgical team and procedural modifications are needed.
Bone marrow-derived mononuclear cells (BMMNCs) have been used for decades in preclinical and clinical studies to treat various neurological diseases. However, there is still a knowledge gap in the ...understanding of the underlying mechanisms of BMMNCs in the treatment of neurological diseases. In addition, prerequisite factors for the efficacy of BMMNC administration, such as the optimal route, dose, and number of administrations, remain unclear. In this review, we discuss known and unknown aspects of BMMNCs, including the cell harvesting, administration route and dose; mechanisms of action; and their applications in neurological diseases, including stroke, cerebral palsy, spinal cord injury, traumatic brain injury, amyotrophic lateral sclerosis, autism spectrum disorder, and epilepsy. Furthermore, recommendations on indications for BMMNC administration and the advantages and limitations of BMMNC applications for neurological diseases are discussed.
Graphical Abstract
BMMNCs in the treatment of neurological diseases. BMMNCs have been applied in several neurological diseases. Proposed mechanisms for the action of BMMNCs include homing, differentiation and paracrine effects (angiogenesis, neuroprotection, and anti-inflammation). Further studies should be performed to determine the optimal cell dose and administration route, the roles of BMMNC subtypes, and the indications for the use of BMMNCs in neurological conditions with and without genetic abnormalities.
Background
We have observed an increased expression of negative markers in some clinical-grade, xeno- and serum-free cultured adipose-derived mesenchymal stem/stromal cell (ADMSC) samples. It gave ...rise to concern that xeno- and serum-free conditions might have unexpected effects on human ADMSCs. This study aims to test this hypothesis for two xeno- and serum-free media, PowerStem MSC1 media (PS) and StemMACS MSC Expansion Media (SM), that support the in vitro expansion of ADMSCs.
Methods
We investigated the expression of negative markers in 42 clinical-grade ADMSC samples expanded in PS. Next, we cultured ADMSCs from seven donors in PS and SM and examined their growth and colony-forming ability, surface marker expression, differentiation, cell cycle and senescence, as well as genetic stability of two passages representing an early and late passage for therapeutic MSCs.
Results
15 of 42 clinical-grade PS-expanded ADMSC samples showed an increased expression of negative markers ranging from 2.73% to 34.24%, which positively correlated with the age of donors. This rise of negative markers was related to an upregulation of Human Leukocyte Antigen – DR (HLA-DR). In addition, the PS-cultured cells presented decreased growth ability, lower frequencies of cells in S/G2/M phases, and increased ß-galactosidase activity in passage 7 suggesting their senescent feature compared to those grown in SM. Although MSCs of both PS and SM cultures were capable of multilineage differentiation, the PS-cultured cells demonstrated chromosomal abnormalities in passage 7 compared to the normal karyotype of their SM counterparts.
Conclusions
These findings suggest that the SM media is more suitable for the expansion of therapeutic ADMSCs than PS. The study also hints a change of ADMSC features at more advanced passages and with increased donor’s age. Thus, it emphasizes the necessity to cover these aspects in the quality control of therapeutic MSC products.
Graphical abstract
Human bone marrow‐derived mesenchymal stem/stromal cells (BM‐MSCs) represent promising stem cell therapy for the treatment of type 2 diabetes mellitus (T2DM), but the results of autologous BM‐MSC ...administration in T2DM patients are contradictory. The purpose of this study was to test the hypothesis that autologous BM‐MSC administration in T2DM patient is safe and that the efficacy of the treatment is dependant on the quality of the autologous BM‐MSC population and administration routes. T2DM patients were enrolled, randomly assigned (1:1) by a computer‐based system into the intravenous and dorsal pancreatic arterial groups. The safety was assessed in all the treated patients, and the efficacy was evaluated based on the absolute changes in the hemoglobin A1c, fasting blood glucose, and C‐peptide levels throughout the 12‐month follow‐up. Our data indicated that autologous BM‐MSC administration was well tolerated in 30 T2DM patients. Short‐term therapeutic effects were observed in patients with T2DM duration of <10 years and a body mass index <23, which is in line with the phenotypic analysis of the autologous BM‐MSC population. T2DM duration directly altered the proliferation rate of BM‐MSCs, abrogated the glycolysis and mitochondria respiration of BM‐MSCs, and induced the accumulation of mitochondria DNA mutation. Our data suggest that autologous administration of BM‐MSCs in the treatment of T2DM should be performed in patients with T2DM duration <10 years and no obesity. Prior to further confirming the effects of T2DM on BM‐MSC biology, future work with a larger cohort focusing on patients with different T2DM history is needed to understand the mechanism underlying our observation.
Human bone marrow‐derived mesenchymal stem/stromal cells (BM‐MSCs) represent promising stem cell therapy for the treatment of type 2 diabetes, but the results of autologous BM‐MSC admniistration in T2DM patients are contradicted. Our data indicated that autologous BM‐MSC administration was well tolerated in 30 T2DM patients. The potential therapeutic effects of the treatments were observed in patients with less than 10 years of T2DM and a BMI<23, and this finding could be explained by reductions in autologous stem cell phenotypes, including prolonged cell proliferation, reduced metabolic functions, and alterations in mtDNA.
Innovation is a complex process and has been shown to be influential towards different types of stakeholders. From the viewpoint of stakeholder theory, shareholders and creditors are more likely to ...be concerned about corporate financial performance. However, in the new era an enterprise’s responsibilities have to extend to other stakeholders, including its employees, suppliers and communities. This study aims to extend the literature by examining the individual effects of product and process innovations, and then their interactions with external collaboration, on firm performance and corporate social responsibility (CSR) activities in terms of local contributions for a sample of Vietnamese manufacturing firms during 2011–2013. Research findings suggest that process and product innovations are beneficial to firm performance in terms of market share, but not return on total assets. This implies that investment in innovative activities requires time to make positive changes in profitability, but it may help with winning customer loyalty. We also find evidence suggesting that innovation could make firms more obscure, especially when there are external parties involved. This motivates firms to send signals about their sustainability and goodwill through corporate social responsibility (CSR) activities. With regard to CSR activities, we are the first to provide a breakdown of categories of corporate social contribution towards the local well-being, and elaborate evidence on the effect of innovation on each category, rather than just a composite index of CSR as in some extant studies.
Stem cell therapy has emerged as a promising method for improving motor function of patients with cerebral palsy. The aim of this study is to assess the safety and effectiveness of autologous bone ...marrow mononuclear stem cell transplantation in patients with cerebral palsy related to oxygen deprivation.
An open label uncontrolled clinical trial was carried out at Vinmec International Hospital. The intervention consisted of two administrations of stem cells, the first at baseline and the second 3 months later. Improvement was monitored at 3 months and 6 months after the first administration of stem cells, using the Gross Motor Function Measure (GMFM) and Modified Ashworth Score which measures muscle tone.
No severe complications were recorded during the study. After transplantation, 12 patients encountered fever without infections and 9 patients experienced vomiting which was easily managed with medications. Gross motor function was markedly improved 3 months or 6 months after stem cell transplantation than at baseline. The post-transplantation GMFM-88 total score, each of its domains and the GMFM-66 percentile were all significantly higher (p-value < 0.001). Muscle spasticity also reduced significantly after transplantation (p-value < 0.001). The therapy was equally effective regardless of sex, age and GMFCS level (p-value > 0.05).
Autologous bone marrow mononuclear cell transplantation appears to be a safe and effective therapy for patients with cerebral palsy.
ClinicalTrials.gov Identifier: NCT02569775 . Retrospectively registered on October 15, 2015.
leaf extract was characterized for its mitigation of the electrochemical corrosion of steel in naturally aerated hydrochloric acid environments by electrochemical methods and surface analysis. The ...presence of
leaf extract (SCLE) in the hydrochloric acid medium ameliorated the corrosion resistance of steel via the adsorption of SCLE species to form a barrier layer. The improved inhibition effectiveness was demonstrated to be independent of the SCLE concentration and the corrosive environment. The highest inhibition performance of approximately 98% was reached for steel in a 1 M HCl medium containing 2500 ppm SCLE. The performance significantly decreased with a decrease in the HCl concentration from 1.00 to 0.01 M with the same SCLE concentration. In addition, severe corrosion occurred on the uninhibited steel surface but was significantly reduced on the inhibited steel surface. The analyzed results also indicated the existence of electronegative functional groups in SCLE, which could promote the adsorption process for the self-formation of the barrier layer on the steel surface. The work reported herein suggested a powerful strategy to mitigate electrochemical corrosion by adding an effective new inhibitor to achieve a green inhibitor system.
The East Vietnam Boundary Fault Zone (EVBFZ) forms the seaward extension of the Red River Shear Zone and interacted with the extensional rift systems in basins along the Central Vietnamese ...continental margin. The structural outline of the central Vietnamese margin and the timing of deformation are therefore fundamental to understanding the development of the South China Sea and its relation to Indochinese escape tectonism and the India-Eurasia collision. This study investigates the structural and stratigraphic evolution of the Central Vietnamese margin in a regional tectonic perspective based on new 2-D seismic and well data. The basin fill is divided into five major Oligocene to Recent sequences separated by unconformities. Deposition and the formation of unconformities were closely linked with transtension, rifting, the opening of the South China Sea and Late Neogene uplift and denudation of the eastern flank of Indochina. The structural outline of the Central Vietnamese margin favors a hybrid tectonic model involving both escape and slab-pull tectonics. Paleogene left-lateral transtension over the NNW-striking EVBFZ, occurred within the Song Hong Basin and the Quang Ngai Graben and over the Da Nang Shelf/western Phu Khanh Basin, related to the escape of Indochina. East of the EVBFZ, Paleogene NE-striking rifting prevailed in the outer Phu Khanh Basin and the Hoang Sa Graben fitting best with a prevailing stress derived from a coeval slab-pull from a subducting proto-South China Sea beneath the southwest Borneo – Palawan region. Major rifting terminated near the end of the Oligocene. However, late stage rifting lasted to the Early Miocene when continental break-up and seafloor spreading commenced along the edge of the outer Phu Khanh Basin. The resulting transgression promoted Lower and Middle Miocene carbonate platform growth on the Da Nang Shelf and the Tri Ton High whereas deeper marine conditions prevailed in the central part of the basins. Partial drowning and platform retreat occurred after the Middle Miocene due to increased siliciclastic input from the Vietnamese mainland. As a result, siliciclastic, marine deposition prevailed offshore Central Vietnam during the Pliocene and Pleistocene.
•The structural outline of the Central Vietnamese margin favors a hybrid tectonic model.•Five major sequences separated by unconformities are investigated.•Major rifting terminated near the end of the Oligocene.•Rifting lasted to the Early Miocene when seafloor spreading commenced along the edge of the study area.•The Tri Ton carbonate platform retreat occurred after the Middle Miocene.
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