Optimization of isolation and purification of total flavonoids from Ardisia mamillata Hance roots using macroporous resins, and determination of their antioxidant activity

Purpose: To isolate, purify and determine the antioxidant property of total flavonoids from the roots of Ardisia mamillata, so as to provide a  theoretical basis for development of natural antioxidants.Methods: Macroporous resin was used to optimize the isolation and  purification of total flavonoids, taking adsorption rate and resolution rate as evaluation indices. The antioxidant property of the purified total flavonoids was determined using 1,1-diphenyl-2-picrylhydrazyl radical 2,2-diphenyl-1-(2,4,6- trinitrophenyl)hydrazyl (DPPH) radical scavenging activity.Results: The best conditions for separation and purification of total  flavonoids from Ardisia mamillata roots were: use of ADS-7 resin, loading total flavonoid concentration of 0.8896 mg/mL, loading buffer flow rate of 1.5 mL/min, loading buffer pH of 4.48, elution ethanol concentration of 60 %, and flow rate of 2.5 mL/min. Under these conditions, the degree of purification of total flavonoids of Ardisia mamillata root was 76.43 ± 0.36 %, adsorption rate was 96.52 ± 0.19 %, while resolution rate was 99.31 ± 0.27 %. When the concentration of the purified total flavonoids was 4.0 mg/mL, its DPPH radical scavenging activity was stronger than that of the standard, butylated hydroxytoluene (BHT), but lower than that of vitamin C.Conclusion: ADS-7 resin is the best macroporous resin for the purification of total flavonoids from the radix of Ardisia mamillata Hance, under the  optimized conditions. The purified total flavonoids of Ardisia mamillata root have stronger DPPH radical scavenging ability than the standard, BHT.Keywords: Szechwan raspberry root, Flavonoids, Macroporous adsorption resin, ADS-7 resin, Purification, Antioxidan

Effects of Mountain Rivers Cascade Hydropower Stations on Water Ecosystems

China is rich in hydropower resources, and mountain rivers have abundant water resources and huge development potential, which have a profound impact on the pattern of water resources allocation in China. As the main way of water resources and hydropower development, the construction of cascade hydropower stations, while meeting the requirements of water resources utilization for social development, has also brought adverse effects on river ecosystems. Therefore, the impact of the construction of cascade hydropower stations on mountainous river ecosystems, where the minimum ecological flow of rivers must be ensured and reviewed. In addition, this paper proposed the deficiencies and outlooks for cascade hydropower stations based on previous research results

Chemical components of volatile oil from Cinnamomum jensenianum Hand Mazz leaf in Yongzhou, and its antibacterial and antioxidant properties

Purpose: To study the chemical components, and in vitro antibacterial and antioxidant properties of volatile oil extracted from Yongzhou Cinnamomum jensenianum Hand. Mazz leaves.Methods: The extraction process of volatile oil in the leaves of Yongzhou Cinnamomum jensenianum Hand. Mazz was optimized with respect to volatile oil yield, and the oil was subjected to gas chromatography-mass spectrometry (GC-MS) analysis. In vitro antimicrobial activities against bacteria and fungi were evaluated by the filter paper method, while in vitro antioxidant potential was determined by assaying its ability to scavenge DPPH radicals.Results: The optimized extraction conditions for volatile oil from the leaves of Yongzhou Cinnamomum jensenianum Hand. Mazz were 3.5 h extraction time, solid-liquid ratio of 1:10, and soaking time of 4 h, which resulted in volatile oil yield of 2.4 ± 0.19 %. A total of 37 components were isolated and identified, accounting for 99.19 % of the volatile oil. The in vitro antimicrobial activities against bacteria and fungi were significant, with minimum inhibitory concentration (MIC) between 10 and 20 uL. At a volatile oil concentration of 0.09 mg/mL, the DPPH scavenging ability of the oil was stronger than that of BHT.Conclusion: There is a high level of extractability of volatile oil from the leaves of Yongzhou Cinnamomum jensenianum Hand. Mazz. The main component is linalool (94.45 %), and it has good antibacterial and antioxidant properties.Keywords: Yongzhou Cinnamomum jensenianum Hand. Mazz, Volatile oil, Antibacterial, Antioxidan

Fully Composable and Adequate Verified Compilation with Direct Refinements between Open Modules (Technical Report)

Verified compilation of open modules (i.e., modules whose functionality depends on other modules) provides a foundation for end-to-end verification of modular programs ubiquitous in contemporary software. However, despite intensive investigation in this topic for decades, the proposed approaches are still difficult to use in practice as they rely on assumptions about the internal working of compilers which make it difficult for external users to apply the verification results. We propose an approach to verified compositional compilation without such assumptions in the setting of verifying compilation of heterogeneous modules written in first-order languages supporting global memory and pointers. Our approach is based on the memory model of CompCert and a new discovery that a Kripke relation with a notion of memory protection can serve as a uniform and composable semantic interface for the compiler passes. By absorbing the rely-guarantee conditions on memory evolution for all compiler passes into this Kripke Memory Relation and by piggybacking requirements on compiler optimizations onto it, we get compositional correctness theorems for realistic optimizing compilers as refinements that directly relate native semantics of open modules and that are ignorant of intermediate compilation processes. Such direct refinements support all the compositionality and adequacy properties essential for verified compilation of open modules. We have applied this approach to the full compilation chain of CompCert with its Clight source language and demonstrated that our compiler correctness theorem is open to composition and intuitive to use with reduced verification complexity through end-to-end verification of non-trivial heterogeneous modules that may freely invoke each other (e.g., mutually recursively)

Process optimization and insecticidal activity of alkaloids from the root bark of Catalpa ovata G. Don by response surface methodology

Purpose: To optimize the extraction of total alkaloids from the root bark of Catalpa ovata using response surface methodology, and to determine the insecticidal activity of the total alkaloids extracted. Methods: A combination of Box-Behnken design and response surface methodology  (RSM) was used to optimize the acid water extraction of total alkaloids from the root bark of Catalpa ovata, with extraction rate of total alkaloids as index and the single factor experiment as basis, and the extraction time, material: liquid ratio and pH as 3 factors. The insecticidal activity of total alkaloids was determined against the three instar armyworm Mythimna separata (Lepidoptera: Noctuidae) and  diamondback moth Plutella xylostella (Lepidoptera: Plutellidae).Results: The optimum extraction conditions for total alkaloids were: material: liquid ratio of 1:10; extraction time of 3 h, pH of 1.0, and simmering. Under these  conditions, total alkaloid extraction was 8.62 %, which was very close to the experimental value. The results were accurate and reliable, with reference value. The insecticidal activity of the total alkaloids indicate that when the concentration of the total alkaloids was 10 mg/L, the fatality rate of Plutella xyllostella and oriental armyworm was over 89 %, but the insecticidal activity of the total alkaloids was lower than that of avermectin which was employed as a reference.Conclusion: The alkaloids from the root bark of Catalpa ovata are potential botanical insecticides.Keywords: Catalpa ovata, Root bark, Total alkaloids, Response surface  methodology, Insecticidal activit

Discussion on the Construction of Ecological Water Network in Guangxi Province of China

The water network plays an important role in maintaining the stability of regional water resource and ecological environment. It is also affecting the harmonious development between environment and economy. Guangxi is one of the provinces with relatively rich water resources in China, while the ecological water network exists deficiencies and faces challenges. The current situation and defects of ecological water network in Guangxi province will be discussed. By studying the experience of the establishing and the preserve of ecological water network in various regions at home and abroad, some suggestions and targeted measures will be mentioned for a better ecological water network in Guangxi

High-fidelity quantitative differential phase contrast deconvolution using dark-field sparse prior

Differential phase contrast (DPC) imaging plays an important role in the family of quantitative phase measurement. However, the reconstruction algorithm for quantitative DPC (qDPC) imaging is not yet optimized, as it does not incorporate the inborn properties of qDPC imaging. In this research, we propose a simple but effective image prior, the dark-field sparse prior (DSP), to facilitate the phase reconstruction quality for all DPC-based phase reconstruction algorithms. The DSP is based on the key observation that most pixel values for an idea differential phase contrast image are zeros since the subtraction of two images under anti-symmetric illumination cancels all background components. With this DSP prior, we formed a new cost function in which L0-norm was used to represent the DSP. Further, we developed the algorithm based on the Half Quadratic Splitting to solve this NP-hard L0-norm problem. We tested our new model on both simulated and experimental data and compare it against state-of-The-Art (SOTA) methods including L2-norm and total variation regularizations. Results show that our proposed model is superior in terms of phase reconstruction quality and implementation efficiency, which significantly increases the experimental robustness, while maintaining the data fidelity. In general, the DSP supports high-fidelity qDPC reconstruction without any modification of the optical system, which simplifies the system complexity and benefit all qDPC applications

Pupil-driven quantitative differential phase contrast imaging

In this research, we reveal the inborn but hitherto ignored properties of quantitative differential phase contrast (qDPC) imaging: the phase transfer function being an edge detection filter. Inspired by this, we highlighted the duality of qDPC between optics and pattern recognition, and propose a simple and effective qDPC reconstruction algorithm, termed Pupil-Driven qDPC (pd-qDPC), to facilitate the phase reconstruction quality for the family of qDPC-based phase reconstruction algorithms. We formed a new cost function in which modified L0-norm was used to represent the pupil-driven edge sparsity, and the qDPC convolution operator is duplicated in the data fidelity term to achieve automatic background removal. Further, we developed the iterative reweighted soft-threshold algorithms based on split Bregman method to solve this modified L0-norm problem. We tested pd-qDPC on both simulated and experimental data and compare against state-of-the-art (SOTA) methods including L2-norm, total variation regularization (TV-qDPC), isotropic-qDPC, and Retinex qDPC algorithms. Results show that our proposed model is superior in terms of phase reconstruction quality and implementation efficiency, in which it significantly increases the experimental robustness while maintaining the data fidelity. In general, the pd-qDPC enables the high-quality qDPC reconstruction without any modification of the optical system. It simplifies the system complexity and benefits the qDPC community and beyond including but not limited to cell segmentation and PTF learning based on the edge filtering property

Soil acidification and salinity: the importance of biochar application to agricultural soils

Soil acidity is a serious problem in agricultural lands as it directly affects the soil, crop production, and human health. Soil acidification in agricultural lands occurs due to the release of protons (H+) from the transforming reactions of various carbon, nitrogen, and sulfur-containing compounds. The use of biochar (BC) has emerged as an excellent tool to manage soil acidity owing to its alkaline nature and its appreciable ability to improve the soil’s physical, chemical, and biological properties. The application of BC to acidic soils improves soil pH, soil organic matter (SOM), cation exchange capacity (CEC), nutrient uptake, microbial activity and diversity, and enzyme activities which mitigate the adverse impacts of acidity on plants. Further, BC application also reduce the concentration of H+ and Al3+ ions and other toxic metals which mitigate the soil acidity and supports plant growth. Similarly, soil salinity (SS) is also a serious concern across the globe and it has a direct impact on global production and food security. Due to its appreciable liming potential BC is also an important amendment to mitigate the adverse impacts of SS. The addition of BC to saline soils improves nutrient homeostasis, nutrient uptake, SOM, CEC, soil microbial activity, enzymatic activity, and water uptake and reduces the accumulation of toxic ions sodium (Na+ and chloride (Cl-). All these BC-mediated changes support plant growth by improving antioxidant activity, photosynthesis efficiency, stomata working, and decrease oxidative damage in plants. Thus, in the present review, we discussed the various mechanisms through which BC improves the soil properties and microbial and enzymatic activities to counter acidity and salinity problems. The present review will increase the existing knowledge about the role of BC to mitigate soil acidity and salinity problems. This will also provide new suggestions to readers on how this knowledge can be used to ameliorate acidic and saline soils

Role of FOXO3 Activated by HIV-1 Tat in HIV-Associated Neurocognitive Disorder Neuronal Apoptosis

There are numerous types of pathological changes in human immunodeficiency virus (HIV)-associated neurocognitive disorder (HAND), including apoptosis of neurons. HIV-1 transactivator of transcription (Tat) protein, which is encoded by HIV-1, may promote apoptosis in HAND. Forkhead box O3 (FOXO3) is a multispecific transcription factor that has roles in many biological processes, including cellular apoptosis. The aim of this study was to determine whether FOXO3 is activated by HIV-1 Tat and to investigate its role in neuronal apoptosis in HAND. We employed tissue staining and related molecular biological experimental methods to confirm our hypothesis. The in vivo experimental results demonstrated that the expression of nuclear FOXO3 increased in the apoptotic neurons of the cerebral cortexes of rhesus macaques infected with simian human immunodeficiency virus (SHIV). The in vitro investigation showed that HIV-1 Tat activated FOXO3, causing it to move from the cytoplasm to the nucleus via the c-Jun N-terminal kinase (JNK) signaling pathway in SH-SY5Y cells. Moreover, FOXO3 down-regulated expression of the anti-apoptosis gene B-cell lymphoma 2 (Bcl-2) and up-regulated the expression of the pro-apoptosis gene Bcl-2-like 11 (Bim) after entering the nucleus, eventually causing cellular apoptosis. Finally, reduction of nuclear FOXO3 reversed cellular apoptosis. Our results suggest that HIV-1 Tat induces FOXO3 to translocate from the cytoplasm to the nucleus via the JNK signaling pathway, leading to neuronal apoptosis. Agents targeting FOXO3 may provide approaches for restoring neuronal function in HAND