Protein stability in stored decellularized heart valve scaffolds and diffusion kinetics of protective molecules.

Decellularized tissues can be used as matrix implants. The aims of this study were to investigate protein stability and solvent accessibility in decellularized pulmonary heart valve tissues. Protein denaturation profiles of tissues were studied by differential scanning calorimetry. Protein solvent accessibility of tissue exposed to D2O, and diffusion kinetics of various protective molecules were studied by Fourier transform infrared spectroscopy. Little changes were observed in the protein denaturation temperature during storage, at either 5 or 40°C. Glycerol was found to stabilize proteins; it increased the protein denaturation temperature. The stabilizing effect of glycerol disappeared after washing the sample with saline solution. Hydrogen-to-deuterium exchange rates of protein amide groups were fastest in leaflet tissue, followed by artery and muscle tissue. Diffusion of glycerol was found to be fastest in muscle tissue, followed by artery and leaflet tissue. Diffusion coefficients were derived and used to estimate the time needed to reach saturation. Fixation of tissue with glutaraldehyde had little effects on exchange and diffusion rates. Diffusion rates decreased with increasing molecular size. Proteins in decellularized heart valve tissue are stable during storage. Glycerol increases protein stability in a reversible manner. Solvent accessibility studies of protein amide groups provide an additional tool to study proteins in tissues. Diffusion coefficients can be derived to simulate diffusion kinetics of protective molecules in tissues. This study provides novel tools to evaluate protein stability and solvent accessibility in tissues, which can be used to develop biopreservation strategies.

[Growth and development of fruit and seed of Panax quinquefolium].

OBJECTIVE: To understand the embryo after-ripening phenomenon of Panax quinquefolium, the growth and development process of fruit and seed was investigated in this study. METHOD: The growth and development characteristics of fruit and seed were obtained by field observation, the morphological changes were measured with a vernier caliper, paraffin section was used as well. RESULT AND CONCLUSION: The plant reached the most flowering numbers in 5-8 d after initial blooming time and the lag phase of embryo occurred in about 70 d. The size, fresh and dry weight of fruit and seed were all reached maximum in fruit maturation period. As the result showed, the development of seed was stopped at torpedo form of embryos, this conclusion can be applied to explore the morphological after-ripening mechanism of P. quinquefolium seed.

Insights into highly effective catalytic persulfate activation on oxygen-functionalized mesoporous carbon for ciprofloxacin degradation.

Nanocarbons have been demonstrated as promising carbon catalysts for substituting metal-based catalysts for the green treatment of wastewater. In this study, oxygen-functionalized mesoporous carbon (OCMK-3) was prepared by wet oxidation and exhibited high catalytic performance against ciprofloxacin (CIP) by activation of persulfate. The effects of environmental parameters (pH, temperature, coexisting ions) and process parameters (temperature, sodium persulfate concentration, catalyst agent dosage, initial concentration) on the removal of CIP were investigated. Compared with the pristine ordered mesoporous carbon (CMK-3), the removal efficiency of CIP by OCMK-3 was increased by 32% under optimal conditions. This rise in activity was attributed to the increase in oxygen-containing functional groups, porosity, and specific surface area of OCMK-3 with improved structural defects and electron transfer efficiency. Furthermore, based on active species scavenging experiments, a dual-pathway mechanism of the radical and nonradical pathways was discovered. The rational degradation pathway of CIP was investigated based on liquid chromatography-mass spectrometry (LC-MS). In addition, the OCMK-3/PS system exhibited high decomposition efficiency in pharmaceutical wastewater treatment. This study provides an in-depth mechanism for the degradation of organic pollutants by carbon-based PS-AOPs and provides theoretical support for further studies.

Comprehensive evaluation of microRNA-10b in digestive system cancers reveals prognostic implication and signaling pathways associated with tumor progression.

Background: Digestive system cancers (DSCs) have been recognized to be linked with high morbidity and mortality. Recent studies have reported that microRNA-10b (miR-10b) is abnormally expressed in DSCs and associated with prognosis. However, the inconclusive results and unknown underlying mechanisms promoted us to perform this study. Methods: We systematic searched several databases for eligible studies and conducted quantitative analysis for evidence regarding the associations between miR-10b and survival outcome of DSCs. We also performed a series of bioinformatics analyses to uncover the potential mechanisms. Results: A total of 32 eligible studies with 3392 patients were included. Increased miR-10b expression was linked with unfavorable overall survival (OS) in DSCs (HR=1.72; 95% CI: 1.30-2.27; P <0.001). When stratified by tumor type, the impact of miR-10b overexpression on poor prognosis was observed in colorectal cancer, gastric cancer, hepatocellular carcinoma, and esophageal carcinoma, but not in pancreatic cancer. Subsequently, we predicted the targets of miR-10b and conducted functional enrichment analyses. The results disclosed that miR-10b targets were predominantly enriched in some vital biological terms and pivotal signaling pathways associated with tumor progression including cell cycle, FoxO, proteoglycans, central carbon metabolism, p53, Notch, HIF-1, focal adhesion, AMPK, and pancreatic cancer. Moreover, a protein-protein interaction (PPI) network was also constructed to identify the top ten hub genes and significant modules and demonstrated the underlying interactions among them. Conclusion: Our results indicated that miR-10b could act as a significant biomarker in the prognosis DSCs. However, more research should be performed to test these findings.

Scanned Proton Beam Performance and Calibration of the Shanghai Advanced Proton Therapy Facility.

The Shanghai Advanced Proton Therapy facility (SAPT) is a hospital-based facility that began construction in December of 2014 with commissioning of the first scanned proton beam line starting in October of 2017. Proton beams are extracted from a synchrotron accelerator with energies between 70 and 235 MeV. Beam delivery uses the modulated scanning and energy stacking techniques to produce a maximal scanning area of 40 × 30 cm2 at the iso-center. Prior to clinical use, the beam delivery system was characterized and calibrated following the guidelines of the IEC 62667 medical electronic equipment standard including the spot size in air, spot position, depth dose distributions, and lateral dose profiles, as well as the beam monitor calibrations following the IAEA TRS-398 recommendations with small differences. •The measured dosimetric results showed that the full width at half maximum (FWHM) for the beam spot size in air varied approximately from 6 mm to 13 mm. The dose fall-off (DDF) derived from the measured depth dose in water varied from 4.7 mm at 235 MeV to 0.7 mm at 70 MeV. The homogeneity of the scanned field was better than 2% for various energies as expected.•Furthermore, the beam reproducibility and proportionality delivery accuracy was also stable with the results better than 0.1% and 1% respectively. Finally, the dose monitor calibration factor, its reproducibility and stability were tested. Reproducibility tests exhibited a standard deviation (SD) result of less than 1% during the test period.•All the measured dosimetric parameters showed that the design specifications were well achieved and the results are suitable for being used as a part of the clinical commissioning and quality assurance program for treating patients.

Effect of iron supplementation during pregnancy on birthweight: evidence from Zimbabwe.

BACKGROUND: Iron deficiency in pregnant women has been shown to reduce the oxygen supply to the fetus, cause intrauterine growth retardation, and increase the risk of premature delivery and reduced birthweight. Yet the effects of iron supplementation programs on pregnancy outcomes are not well documented for developing countries. OBJECTIVE: To examine the relation between iron supplementation of mothers during pregnancy and children's birthweight using data from a national population-based survey in Zimbabwe. METHODS: The analysis uses information on 3559 births during the five years preceding the 1999 Zimbabwe Demographic and Health Survey. The effect of iron supplementation during pregnancy on birthweight was estimated by multiple regression, controlling for potential confounding effects of prenatal care, child's sex and birth order, mother's education and nutritional status (measured by body-mass index), household living standard, smoke exposure, and other variables. RESULTS: Babies born to mothers who received iron supplementation during pregnancy were 103 g heavier (95% confidence interval, 42-164; p = .001), on average, than babies born to mothers who did not receive iron supplementation during pregnancy. The difference was 64 g (95% confidence interval, 2-125; p = .043) for children whose birthweights were taken from health cards and 163 g (95% confidence interval, 44-281; p = .008) for children whose birthweights were reported by their mothers. CONCLUSIONS: Iron supplementation during pregnancy is associated with significantly higher birthweight, independent of other pregnancy care factors, mother's nutritional status, smoke exposure, and a number of demographic and socioeconomic factors. Prenatal iron supplementation programs can improve pregnancy outcomes and promote child survival in developing countries.

Maternal exposure to biomass smoke and reduced birth weight in Zimbabwe.

PURPOSE: To examine the association between household use of biomass fuels for cooking and birth weight. METHODS: Analysis is based on 3559 childbirths in the 5 years preceding the 1999 Zimbabwe Demographic and Health Survey. Birth weights, recorded by trained professionals at local health clinics, were derived from health cards at home or from mother's recall. Multiple regression method was used to estimate the effect of household use of biomass cooking fuels (wood, dung, or straw) on birth weight, after controlling for child's sex and birth order, mother's education and nutritional status, pregnancy care, household living standard, and other potentially confounding factors. RESULTS: Babies born to mothers cooking with wood, dung, or straw were 175 g lighter (95% CI,-300,-50), on average, compared with babies born to mothers using LPG, natural gas, or electricity. The difference was 120 g (95% CI,-301, 61) for children whose birth weights were taken from health cards, and 183 g (95% CI,-376, 10) for children whose birth weights were reported by mothers. CONCLUSIONS: Household use of high pollution cooking fuels may cause reduced birth weight. The relationship needs to be further investigated using more direct measures of smoke exposure and birth weight and accounting for environmental tobacco smoke.