The effects of solvent extraction on nanoporosity of marine-continental coal and mudstone

Coal and organic-rich mudstone develop massive nanopores, which control the storage of adsorbed and free gas, as well as fluid flows. Generation and retention of bitumen and hydrocarbons of oil window reservoirs add more uncertainty to the nanoporosity. Solvent extraction is a traditional way to regain unobstructed pore networks but may cause additional effects due to interactions with rocks, such as solvent adsorbing on clay surfaces or absorbing in kerogens. Selected marine-continental coal and mudstone in Eastern Ordos Basin were studied to investigate how pore structures are affected by these in-situ-sorptive compounds (namely residual bitumen and hydrocarbons) and altered by solvent extractions. Solvent extraction was performed to obtain bitumen-free subsamples. Organic petrology, bulk geochemical analyses and gas chromatography were used to characterize the samples and the extracts. Low-pressure argon and carbon dioxide adsorptions were utilized to characterize the nanopore structures of the samples before and after extraction. The samples, both coal and mudstone, are in oil windows, with vitrinite reflectance ranging from 0.807 to 1.135%. The coals are strongly affected by marine organic input, except for the sample C-4; the mudstones are sourced by either marine or terrestrial organic input, or their mixture. As for the coals affected by marine organic input, residual bitumen and hydrocarbons occupying or blocking pores <10 nm becomes weak with thermal maturation. Bitumen derived from terrestrial organic matter mainly affects small pores, since coal asphaltene molecules are much smaller than petroleum asphaltene molecules. The mudstone M-2 with high extract production showed an increase of nanopores after extraction, due to the exposure of the filled or blocked pores. However, most transitional mudstones saw decreases of the pores because pore shrinkage caused by solvents adsorbing on and swelling clay minerals (mainly kaolinite and illite/smectite mixed layers) counteracts the released pore spaces. Solvent extractions on the coals significantly increased the micropores <0.6 nm, since the heat of sorption of alkanes reaches the peak in the pores within 0.4–0.5 nm. By contrast, solvent extractions on the mudstones decreased the micropores ∼0.35 nm, which is perhaps caused by evaporative drying of solvent displacing residual water in clay

Metabolic response of Nile tilapia (Oreochromis niloticus) to acute and chronic hypoxia stress

© 2018 Elsevier BV. This manuscript version is made available under the CC-BY-NC-ND 4.0 license: http://creativecommons.org/licenses/by-nc-nd/4.0/ This author accepted manuscript is made available following 24 month embargo from date of publication (May 2018) in accordance with the publisher’s archiving policy.Hypoxia is a critical issue in aquaculture especially in intensive aquaculture systems. Acute hypoxia stress with dissolved oxygen (DO) 0.7±0.1 mg/L for 6 h and chronic hypoxia stress with DO 1.1±0.1 mg/L for 4 weeks were used to investigate the response of nutritional metabolic pathways in Nile tilapia Oreochromis niloticus. Fish in the acute and chronic experiments had different adaptive mechanisms. Upon acute hypoxia stress, the contents of liver glycogen and muscle glycogen were significantly lower, but there was no significant difference in triglycerides (TG). The lactate dehydrogenase (LDH) activities increased after exposure to acute hypoxia stress. The mRNA expression of genes involved in glycolysis and glycogenolysis was significantly up-regulated by acute hypoxia stress. However, the response of fish to long-term hypoxia stress was different from acute hypoxia. Compared with the normoxia treatment, the crude fat in fish decreased in the hypoxia group and TG in the liver and muscle were significantly lower. Beta oxidation of the liver was enhanced in the hypoxia group, while the hepatic glycogen content increased in the hypoxia group. Transcriptomic analysis showed that the expression of genes related to carbohydrate synthesis and lipolysis increased in the hypoxia group, while genes related to carbohydrate catabolism and fat synthesis showed the opposite. This study indicates that fish could utilize carbohydrate as a main energy source during acute hypoxia stress, and metabolize more lipid during long-term hypoxia stress. A high carbohydrate content in the diet may help reduce negative effects from acute hypoxia stress, and an appropriate increase of fat content in the diet may benefit fish growth in a hypoxia environment, e.g., in high-density aquaculture ponds

α-lipoic acid regulate growth, antioxidant status and lipid metabolism of Chinese mitten crab Eriocheir sinensis: Optimum supplement level and metabonomics response

© 2019 Elsevier B.V. This manuscript version is made available under the CC-BY-NC-ND 4.0 license: http://creativecommons.org/licenses/by-nc-nd/4.0/ This author accepted manuscript is made available following 24 month embargo from date of publication (March 2019) in accordance with the publisher’s archiving policyThe α-lipoic acid (α-LA) is a novel feed additive to improve growth, antioxidant capacity and lipid metabolism in animal husbandry. In this study, isonitrogenous and isoenergetic diets were formulated at seven levels of α-LA (0, 300, 600, 1200, 2400, 4800, or 9600 mg/kg) and fed to the Chinese mitten crab Eriocheir sinensis juveniles for eight weeks. According to weight gain and specific grwoth rate, the optimal level of α-LA supplement in the diet is estimated at 1339–1574 mg/kg for E. sinensis. The α-LA supplement significantly increased the activities of SOD, GSH-Px and T-AOC, and the content of GSH in the hepatopancreas except for SOD in the crabs fed 9600 mg/kg α-LA. Excess dietary α-LA supplement increased the content of MDA in the hepatopancreas. The E. sinensis fed 2400 mg/kg α-LA in the diet showed the highest mRNA expressions of es_TGL1, es_TGL2, es_IL and es_DGL and had higher lipid catabolism when taking 300 mg/kg α-LA than other diets, which coincides with higher mRNA expressions of es_IL, es_DGL and CPT-1 in the hepatopancreas. The crab fed 2400 mg/kg α-LA significantly modified 45 metabolites in serum compared with the control. The supplmentation of α-LA significantly influenced fatty acid metabolism, amino acid metabolism, carnitine metabolism and accumulation of plant antioxidants. This study indicates that α-LA is a promising feed additive to regulate growth, antioxidant status and lipid metabolism in E. sinensis, but its inclusion in the diet should be <2400 mg/kg α-LA to maximize the benefitial effect and minimize side effects

Seroprevalence of Pandemic (H1N1) 2009 in Pregnant Women in China: An Observational Study

BACKGROUND: We investigated the seropositive rates and persistence of antibody against pandemic (H1N1) 2009 virus (pH1N1) in pregnant women and voluntary blood donors after the second wave of the pandemic in Nanjing, China. METHODOLOGY/PRINCIPAL FINDINGS: Serum samples of unvaccinated pregnant women (n = 720) and voluntary blood donors (n = 320) were collected after the second wave of 2009 pandemic in Nanjing. All samples were tested against pH1N1 strain (A/California/7/2009) with hemagglutination inhibition assay. A significant decline in seropositive rates, from above 50% to about 20%, was observed in pregnant women and voluntary blood donors fifteen weeks after the second wave of the pandemic. A quarter of the samples were tested against a seasonal H1N1 strain (A/Brisbane/59/2007). The antibody titers against pH1N1 strain were found to correlate positively with those against seasonal H1N1 strain. The correlation was modest but statistically significant. CONCLUSIONS AND SIGNIFICANCE: The high seropositive rates in both pregnant women and voluntary blood donors suggested that the pH1N1 virus had widely spread in these two populations. Immunity derived from natural infection seemed not to be persistent well

l-Tryptophan synergistically increased carotenoid accumulation with blue light in maize (Zea mays L.) sprouts

In the present study, l-tryptophan was applied in combination with blue light to modulate carotenoid biosynthesis in maize sprouts. The profiles of carotenoids, chlorophylls, and relative genes in carotenoid biosynthesis and light signaling pathways were studied. l-tryptophan and blue light both promoted the accumulation of carotenoids, and their combination further increased carotenoid content by 120%. l-tryptophan exerted auxin-like effects and stimulated PSY expression in blue light exposure maize sprouts, resulting in increased α- and β- carotenes. l-tryptophan could also play a photoprotective role through the xanthophyll cycle under blue light. In addition, CRY in the light signaling pathway was critical for carotenoid biosynthesis. These findings provide new insights into the regulation of carotenoid biosynthesis and l-tryptophan could be used in conjunction with blue light to fortify carotenoids in maize sprouts

An Ice Core Slice Scanning Tool based on Line-scan Camera

The ice core from polar ice sheet is one of the most valuable archives of past climate and environment. The ice core visual stratigraphy, based on optical scanning analysis, provides the most intuitive information of the micro-particles and/or air bubbles in the ice. At present, only few labs can perform high quality visual stratigraphy analysis in the world. Here, we develop an ice core slice scanning tool based on line-scan camera. The machine uses the high-resolution characteristics of the line-scan camera to complete high-resolution imaging of the ice core slices through linkage with the linear light sources. A motor drive and control system is developed to complete the uniform scanning control of the line-scan camera and light sources. A special control program and human-computer interaction interface are developed to realize the parameter setting, motor control and imaging result display. The test results show that the proposed ice core slice scanning tool meets the design requirements and its imaging results are significantly better than area-scan cameras under the same conditions

Data_Sheet_1_Exploration of validity evidence for core residency entrustable professional activities in Chinese pediatric residency.zip

IntroductionThis study seeks to explore validity and reliability evidence for core residency entrustable professional activities (CR-EPAs) that were developed by Peking University First Hospital (PKUFH) in 2020.MethodsA prospective cohort study was conducted in PKUFH. Trainers (raters) assessed pediatric residents on CR-EPAs over 1 academic year, bi-annually. Critical components within a validity evidence framework were examined: response process (rater perceptions), the internal structure (reliability and contributions of different variance sources), and consequences (potential use of a cutoff score).ResultsIn total, 37 residents were enrolled, and 111 and 99 trainers’ ratings were collected in Fall 2020 and Spring 2021, respectively. For rater perceptions, all the raters considered CR-EPAs highly operational and convenient. In all ratings, individual EPAs correlate with total EPA moderately, with Spearman correlation coefficients spanning from 0.805 to 0.919. EPA 2 (select and interpret the auxiliary examinations), EPA 5 (prepare and complete medical documents), EPA 6 (provide an oral presentation of a case or a clinical encounter), and EPA 7 (identify and manage the general clinical conditions) were EPAs correlated with other EPAs significantly. The results of the generalizability theory indicated that the variability due to residents is the highest (nearly 78.5%), leading to a large size of the reliability estimates. The matching results indicate that the lowest error locates at 5.933.ConclusionThe rating showed good validity and reliability. The ratings were reliable based on G-theory. CR-EPAs have a magnificent internal structure and have promising consequences. Our results indicate that CR-EPAs are a robust assessment tool in workplace-based training in a carefully designed setting.</p