117 research outputs found
Physicochemical Properties of Various 2-Hydroxyethylammonium Sulfonate -Based Protic Ionic Liquids and Their Potential Application in Hydrodeoxygenation
In order to obtain the regularities of physicochemical properties of hydroxy protic ionic liquids (PILs) and broaden their potential application, a series of 2-hydroxyethylammonium sulfonate-based PILs were synthesized through proton transfer reaction and characterized by NMR and FT-IR and elemental analysis. Their phase transfer behavior (Tm) and initial decomposition point (Td) were characterized by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively. Meanwhile, the regularities of density (ρ), viscosity (η) and electrical conductivity (σ) of synthesized PILs at different temperatures were measured. The results indicated that their physicochemical properties were tightly related with their structures and the interactions between cations and anions. In addition, the dissociation constants (pKa) of synthesized PILs were obtained by acid-base titration, which revealed that all synthesized PILs had pKa exceeding 7 and their cations were the crux of determining the pKa value. Moreover, several synthesized PILs with a low melting temperature also showed potential application in the deoxidation reaction of cyclohexanol, as they had conversion rates approximating 100% and the selectivity of cyclohexane or cyclohexene was about 80%
Genetic modification of Mucor circinelloides for canthaxanthin production by heterologous expression of β-carotene ketolase gene
11 pags, 4 figs, 1 tab. -- he Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fnut.2021.756218/full#supplementary-materiaCanthaxanthin is a reddish-orange xanthophyll with strong antioxidant activity and higher bioavailability than carotenes, primarily used in food, cosmetics, aquaculture, and pharmaceutical industries. The spiking market for natural canthaxanthin promoted researchers toward genetic engineering of heterologous hosts for canthaxanthin production. Mucor circinelloides is a dimorphic fungus that produces β-carotene as the major carotenoid and is considered as a model organism for carotenogenic studies. In this study, canthaxanthin-producing M. circinelloides strain was developed by integrating the codon-optimized β-carotene ketolase gene (bkt) of the Haematococcus pluvialis into the genome of the fungus under the control of strong promoter zrt1. First, a basic plasmid was constructed to disrupt crgA gene, a negative regulator of carotene biosynthesis resulted in substantial β-carotene production, which served as the building block for canthaxanthin by further enzymatic reaction of the ketolase enzyme. The genetically engineered strain produced a significant amount (576 ± 28 μg/g) of canthaxanthin, which is the highest amount reported in Mucor to date. Moreover, the cell dry weight of the recombinant strain was also determined, producing up to more than 9.0 g/L, after 96 h. The mRNA expression level of bkt in the overexpressing strain was analyzed by RT-qPCR, which increased by 5.3-, 4.1-, and 3-folds at 24, 48, and 72 h, respectively, compared with the control strain. The canthaxanthin-producing M. circinelloides strain obtained in this study provided a basis for further improving the biotechnological production of canthaxanthin and suggested a useful approach for the construction of more valuable carotenoids, such as astaxanthin.This work was supported by the National Natural Science Foundation of China (Grant Nos. 31670064 and 31972851), the Tai Shan Industrial Experts Program tscy 20160101, and the Shandong provincial key technology R&D plan (2018GNC110039, 2018GSF121013).Peer reviewe
Traditional Chinese medicine in osteoporosis: from pathogenesis to potential activity
Osteoporosis characterized by decreased bone density and mass, is a systemic bone disease with the destruction of microstructure and increase in fragility. Osteoporosis is attributed to multiple causes, including aging, inflammation, diabetes mellitus, and other factors induced by the adverse effects of medications. Without treatment, osteoporosis will further progress and bring great trouble to human life. Due to the various causes, the treatment of osteoporosis is mainly aimed at improving bone metabolism, inhibiting bone resorption, and promoting bone formation. Although the currently approved drugs can reduce the risk of fragility fractures in individuals, a single drug has limitations in terms of safety and effectiveness. By contrast, traditional Chinese medicine (TCM), a characteristic discipline in China, including syndrome differentiation, Chinese medicine prescription, and active ingredients, shows unique advantages in the treatment of osteoporosis and has received attention all over the world. Therefore, this review summarized the pathogenic factors, pathogenesis, therapy limitations, and advantages of TCM, aiming at providing new ideas for the prevention and treatment of OP
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Breast cancer risk factors in relation to molecular subtypes in breast cancer patients from Kenya
Background
Few studies have investigated risk factor heterogeneity by molecular subtypes in indigenous African populations where prevalence of traditional breast cancer (BC) risk factors, genetic background, and environmental exposures show marked differences compared to European ancestry populations.
Methods
We conducted a case-only analysis of 838 pathologically confirmed BC cases recruited from 5 groups of public, faith-based, and private institutions across Kenya between March 2012 to May 2015. Centralized pathology review and immunohistochemistry (IHC) for key markers (ER, PR, HER2, EGFR, CK5-6, and Ki67) was performed to define subtypes. Risk factor data was collected at time of diagnosis through a questionnaire. Multivariable polytomous logistic regression models were used to determine associations between BC risk factors and tumor molecular subtypes, adjusted for clinical characteristics and risk factors.
Results
The median age at menarche and first pregnancy were 14 and 21 years, median number of children was 3, and breastfeeding duration was 62 months per child. Distribution of molecular subtypes for luminal A, luminal B, HER2-enriched, and triple negative (TN) breast cancers was 34.8%, 35.8%, 10.7%, and 18.6%, respectively. After adjusting for covariates, compared to patients with ER-positive tumors, ER-negative patients were more likely to have higher parity (OR = 2.03, 95% CI = (1.11, 3.72), p = 0.021, comparing ≥ 5 to ≤ 2 children). Compared to patients with luminal A tumors, luminal B patients were more likely to have lower parity (OR = 0.45, 95% CI = 0.23, 0.87, p = 0.018, comparing ≥ 5 to ≤ 2 children); HER2-enriched patients were less likely to be obese (OR = 0.36, 95% CI = 0.16, 0.81, p = 0.013) or older age at menopause (OR = 0.38, 95% CI = 0.15, 0.997, p = 0.049). Body mass index (BMI), either overall or by menopausal status, did not vary significantly by ER status. Overall, cumulative or average breastfeeding duration did not vary significantly across subtypes.
Conclusions
In Kenya, we found associations between parity-related risk factors and ER status consistent with observations in European ancestry populations, but differing associations with BMI and breastfeeding. Inclusion of diverse populations in cancer etiology studies is needed to develop population and subtype-specific risk prediction/prevention strategies
Distributed Anonymous e-Voting Method Based on Smart Contract Authentication
With the development of science and technology, the traditional centralized ballot management will lead to the risk of an opaque voting process and tampering of back-end data, and it can no longer meet the requirements of e-voting transparency and anonymity, while the distributed blockchain technology, with its features of being transparent and tamper-proof, can well solve the problems in traditional e-voting and make the ballot firmly in the hands of users. To make each node reach consensus, each node can access the complete shared ledger, and malicious nodes can analyze the transaction information in the ledger to obtain users’ voting information, which makes anonymity impossible to guarantee. We propose a blockchain technology-based voting record synchronization model and an anonymous authentication model, using zk-SNARK and Merkle tree technology, that achieve user authentication and anonymous voting. In this scheme, the user’s random identity address is inserted into the Merkle tree, and when voting, it is only necessary to prove that the user’s identity address is in the tree to complete anonymous voting without revealing the user’s real identity. This scheme meets the basic requirements of electronic voting and ensures the reliability and security of voting
Legislative Documents
Also, variously referred to as: House bills; House documents; House legislative documents; legislative documents; General Court documents
Study on ionic liquids based novel method for separation and purification of silkworm pupa protein
Silkworm pupa protein (SPP) that obtained by traditional method usually had a high fat content, which would impose restrictions on the further use of SPP. Herein, various functionalized ionic liquids (ILs) were used to extract SPP from silkworm pupae, the structure-performance relationship of ILs with their SPP separation performance were explored at the same time. The research showed that the maxi-mum extraction yield of SPP was up to 62.6% with less than 0.5% low fat content by using 1-ethyl-3-methylimidazolium chloride ([Emim]Cl), when the dissolution experiment was conducted at 90 ? for 24 h with ethanol bath as the regeneration solvent. Comparing with the structure of raw material, the regenerated SPP maintained the native protein backbone. Meanwhile, all regenerated SPP showed a de-creased crystallinity, which also exhibited decreased fraction of the alpha-helix comparing to that beta-sheet united with coil random structures. (C) 2022 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences
Study on ionic liquids based novel method for separation and purification of silkworm pupa protein
Silkworm pupa protein (SPP) that obtained by traditional method usually had a high fat content, which would impose restrictions on the further use of SPP. Herein, various functionalized ionic liquids (ILs) were used to extract SPP from silkworm pupae, the structure-performance relationship of ILs with their SPP separation performance were explored at the same time. The research showed that the maxi-mum extraction yield of SPP was up to 62.6% with less than 0.5% low fat content by using 1-ethyl-3-methylimidazolium chloride ([Emim]Cl), when the dissolution experiment was conducted at 90 ? for 24 h with ethanol bath as the regeneration solvent. Comparing with the structure of raw material, the regenerated SPP maintained the native protein backbone. Meanwhile, all regenerated SPP showed a de-creased crystallinity, which also exhibited decreased fraction of the alpha-helix comparing to that beta-sheet united with coil random structures. (C) 2022 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences
Online Pyrometry Calibration for Industrial Combustion Process Monitoring
Temperature and its distribution are crucial for combustion monitoring and control. For this application, digital camera-based pyrometers become increasingly popular, due to its relatively low cost. However, these pyrometers are not universally applicable due to the dependence of calibration. Compared with pyrometers, monitoring cameras exist in all most every combustion chamber. Although these cameras, theologically, have the ability to measure temperature, due to lack of calibration they are only used for visualization to support the decisions of operators. Almost all existing calibration methods are laboratory-based, and hence cannot calibrate a camera in operation. This paper proposes an online calibration method. It uses a pre-calibrated camera as a standard pyrometer to calibrate another camera in operation. The calibration is based on a photo taken by the pyrometry-camera at a position close to the camera in operation. Since the calibration does not affect the use of the camera in operation, it sharply reduces the cost and difficulty of pyrometer calibration. In this paper, a procedure of online calibration is proposed, and the advice about how to set camera parameters is given. Besides, the radio pyrometry is revised for a wider temperature range. The online calibration algorithm is developed based on two assumptions for images of the same flame taken in proximity: (1) there are common regions between the two images taken at close position; (2) there are some constant characteristic temperatures between the two-dimensional temperature distributions of the same flame taken from different angles. And those two assumptions are verified in a real industrial plants. Based on these two verified features, a temperature distribution matching algorithm is developed to calibrate pyrometers online. This method was tested and validated in an industrial-scale municipal solid waste incinerator. The accuracy of the calibrated pyrometer is sufficient for flame monitoring and control
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