Controlled Synthesis of Titania using Water-soluble Titanium Complexes: A Review

The development of human society has led to the increase in energy and resources consumption as well as the arising problems of environmental damage and the toxicity to the human health. The development of novel synthesis method which tolerates utilization of toxic solvents and chemicals would fulfill the demand of the society for safer, softer, and environmental friendly technologies. For the past decades, a remarkable progress has been attained in the development of new water-soluble titanium complexes (WSTC) and their use for the synthesis of nanocrystalline titanium dioxide materials by aqueous solution-based approaches. The progress of synthesis of nanocrystalline titanium dioxide using such WSTCs is reviewed in this work. The key structural features responsible for the successfully controlled synthesis of TiO2 are discussed to provide guidelines for the morphology-controlled synthesis. Finally, this review ends with a summary and some perspectives on the challenges as well as new directions in this fascinating research

ANTECEDENTS OF TOURISTS’ LOYALTY: THE ROLE AND INFLUENCE OF TOURISM PRODUCTS, DESTINATION IMAGE IN HOIAN WORLD CULTURAL HERITAGE SITE

The study’s aim is to examine the antecedents of destination loyalty, and considers the role and influence of tourism products and destination image to international tourisms’ loyalty in case of HoiAn World Cultural Heritage Site. The study suggested an integrated approach to understand tourists’ loyalty model and investigate the empirical evidence about the relationship among tourism products, destination image, risk perception, tourist experience, destination satisfaction and tourists’ loyalty. This study also mentions important questions concerning how tourism products, destination image, tourist experience, risk perception, and tourists’ satisfaction affect tourists’ loyalty. Smart PLS3 is used to estimate and test the relationships in the research model. Mediation analysis and importance performance matrix analysis are also used to consider clearly the relationship between the constructs of research model. The study’s results indicate that tourism products, destination image, tourism experience, risk perception, and satisfaction are antecedents of international tourists’ loyalty in Hoi An World Cultural Heritage Site. And in them, tourism products affect significantly positively to destination imagine and satisfaction, beside destination image and satisfaction hold the role of mediator in this relationship. Implementing IPMA to identify the predecessors that have relatively high importance for loyalty but also a relatively low performance. The results pointed out that the constructs as satisfaction, tourism product, risk perception and image have a high importance for the tourist loyalty. The study added the antecedent of tourism products and risk perception to the model and could enrich the literature, pointing to be possibility of a destination loyalty model that can be applied to various contexts, especially after COVID- 19 pandemic. The study also discussed theoretical and managerial implications for marketing tourism

STUDY ON INSPECTION OF THE PUTATIVE HYBRIDS BETWEEN TRACK-LACKING WILD MALE GAUR (BOS GAURUS) AND DOMESTIC FEMALE COW (BOS TAURUS) IN PHUOC BINH NATIONAL PARK, VIETNAM

Hybridization between wild and domestic bovine occurs widely due to the overlapping of the natural habitat of the wild and human farm animals. Due to the loss of habitat, the number of wild gaur (Bos gaurus) in Vietnam was in serious decline. Since 2009, a male wild gaur (Bos gaurus) has appeared and incorporated with female domestic cows (Bos taurus) in buffer zone Phuoc Binh National Park, on the border with Lam Dong and Ninh Thuan provinces. Then, several calves were born that carried some traits of wild gaur including physical characteristics and behaviors. These calves were supposed to be offspring between wild gaur and domestic cows. In previous study, the karyotypes of putative calves were identified with 2n = 58 and non-homologous chromosome 28 and 29 in these hybrids. In this study, we characterized the putative hybrids between track-lacking Bos gaurus and Bos taurus for breeding and preservation using Cytochrome b analysis, microsatellites and a novel marker growth hormone factor 1 (POU1F1). Cytochrome b analysis indicated the maternal lineage of the putative hybrids, with 100% nucleotide sequence identity. Microsatellite BM861 and sequence of ZFY gene region reveal Bos taurus chromosome Y origin was among the male putative hybrids. Importantly, the analysis of POU1F1 gene sequence on 1 chromosome showed efficacy in determining both Bos gaurus and Bos taurus lineage in the putative hybrids. The karyotyping results were confirmed by molecular analysis and our results provide a feasible way for detecting the putative hybrids between wild and domestic cattle in case of lacking the wild trace

Chemical diversity of essential oils of rhizomes of six species of Zingiberaceae family

In this study, the essential oils from the rhizomes of six species belonging to the Zingiberaceae family, including Zingiber zerumbet, Curcuma pierreana, Globba macrocarpa, Alpinia conchigera, Stahlianthus campanulatus and Amomum sp., collected in Binh Chau-Phuoc Buu Nature Reserve were isolated using hydrodistillation, and their constituents were identified via Gas Chromatography-Mass Spectrometry. A total of 91 constituents have been identified from essential oils. These compounds were classified into 4 clusters by Agglomerative Hierarchical Clustering (AHC) and Principal Component Analysis (PCA) analysis. The principal constituents of the essential oils isolated from four species, C. pierreana, S. campanulatus, A. conchigera, and Z. zerumbet contained camphene (18.82%), α-copaene (11.75%), p-xylene (21.86%), and α-santalene (17.91%), which were significantly different from those in previous reports. Furthermore, this study revealed the chemical constituents of essential oils of G. macrocarpa and Amomum sp. for the first time. Accordingly, artemisia triene (22.21%), β-pinene (13.57%), 4,6,8-trimethylazulene (11.1%), 2-tert-butylquinoline (9.86%), β-patchoulene (7.06%), α-elemene (6.93%), and β-ocimene (6.0%) were the major compounds in essential oils of G. macrocarpa rhizomes whereas the oil of Amomum sp. was found to be rich in 2-carene (21.82%), fenchyl acetate (14.26%), 3-carene (8.28%), bornyl acetate (7.7%), and D-limonene (7.13%)

PRELIMINARY STUDY OF THE ANTIOXIDANT PROPERTIES OF OPHIOCORDYCEPS SOBOLIFERA

The aim of study was to determine preliminary phytochemical analysis and the antioxidant potential of Ophiocordyceps sobolifera. The antioxidant activity of Ophiocordyceps sobolifera was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and total antioxidant activity methods. Phytochemical analyses revealed the presence of steroids, triterpenoids, alkaloids, phenolics, flavoinods, protein, carbohydarte and saponins. The antioxidant activity of the ethanol extracts and water extracts showed high antioxidant activity with the lowest half maximal inhibitory concentration (IC50) values to 0.70 from 0.95mg/mL, realtively. Total antioxidant capacity of the O. sobolifera showed contained from 5.52 ± 0.14 to 12,71 ± 0.23 mg GA/g or from 3.55 ± 0.15 to 7.87 ± .05 μmol AS/g. These data suggest that O. sobolifera is a natural source of antioxidants

In vitro antioxidant activity and bioactive compounds from Calocybe indica

Nowadays, the use of mushrooms in medicine is ubiquitous and has achieved particular success. The antioxidants in mushrooms can deactivate free radicals. This study assesses the antioxidant potential of mushroom Calocybe indica with the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging methods and the total antioxidant capacity. The mushroom’s ethanol extract exhibits acceptable activity with a low IC50 value (240.11 μg/mL), approximately 2.9 times lower than that of the mushroom Ophiocordyceps sobolifera extract. The ABTS scavenging rate of the extract is around 60% at 500 µg/mL, and the total antioxidant capacity is equivalent to 64.94 ± 1.03 mg of GA/g or 77.42 ± 0.42 μmol of AS/g.  The total phenolics, flavonoids, polysaccharides, and triterpenoids are equivalent to 29.33 ± 0.16 mg of GAE/g, 17.84 ± 0.11 mg of QUE/g (5.04 ± 0.04%), and 4.96 ± 0.04 mg of oleanolic acid/g, respectively. Specifically, the total triterpenoid content has been reported for the first time. The mushroom can have potential biomedical applications

Fuzzy Equivalence on Standard and Rough Neutrosophic Sets and Applications to Clustering Analysis

In this paper, we propose the concept of fuzzy equivalence on standard neutrosophic sets and rough standard neutrosophic sets. We also provide some formulas for fuzzy equivalence on standard neutrosophic sets and rough standard neutrosophic sets. We also apply these formulas for cluster analysis. Numerical examples are illustrated

Polysaccharide extraction from Myxopyrum smilacifolium trunk and its antioxidant capacity

As a traditional medicinal plant in Vietnam, Myxopyrum smilacifolium has been used for a long history to treat cough, nervous disorders, numbness, rheumatism, and cephalalgia. Nevertheless, reports on the antioxidant activity and extraction of M. smilacifolium polysaccharides are still very rare. This study was designed to extract a high yield of polysaccharides from the M. smilacifolium trunk and characterize it. As a result, the maximum yield of the polysaccharides of 5.13 ± 0.05% was obtained with an extraction time of three hours, extraction temperature of 100 oC, the ratio of water to sample of 1:50 as extraction solution, extraction number of times 3, and the ratio of ethanol to extract volume 5:1 (v/v). Polysaccharides was characterized by Fourier transform infrared spectroscopy (FT-IR) and high-performance gel-permeation chromatography (HPGPC). The average molecular weight of extracted polysaccharides was around 3.78 × 105 Da. In vitro assays dan impressive antioxidant activities of the extracted polysaccharides, containing 0.2423 ± 0.0028 mg GA/g or 0.2142 ± 0.0007 μmol AS/g. The IC50 values of polysaccharides in the DPPH and ABTS methods were 0.89 mg/mL and 3.85 mg/mL, respectively.  These findings exhibited the potential for application or further research and development of polysaccharides from Myxopyrum smilacifolium