In this report, the adsorption of Cr(VI) onto MnO2/CS nanocomposite material from aqueous solution is investigated. All the factors, which affect the adsorption, such as pH, adsorption time, Cr(VI) ...initial concentration and adsorbent dosage, are also examined. The results obtained show that the Cr(VI) uptake is strongly affected by pH and ion strength. Analysis within the nonlinear isotherm models indicates that the Sips isotherm combining with the Langmuir and Freundlich models offer the best fit to the experimental data due to the obtained highest R2 and smallest RMSE and χ2 values. The calculated Langmuir monolayer adsorption capacity is 61.56 mg g−1 at pH of 2.0 and adsorption time of 120 min. Moreover, the mechanism studies by combining theoretical models with analytical spectroscopies reveal that the electrostatic attraction plays the important role to the uptake of Cr(VI) onto MnO2/CS nanocomposite. Therefore, the present nanocomposite material can be applied to remove total Cr from wastewater produced by the galvanized manufacturing factory with a relatively high efficiency.
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•MnO2/CS nanocomposite was used as an adsorbent to remove Cr(VI) from aqueous solution.•The Langmuir monolayer adsorption capacity is 61.56 mg g−1.•The primary mechanism of the uptake of Cr(VI) onto MnO2/CS was proposed.•MnO2/CS was applied to remove total Cr in effluent with the high removal of 94.21%.
An analysis of nutritional composition of some common fruits (persimmon, banana, lemon, longan) grown in Northern Vietnam was conducted. These fruits, at their ripening stage, showed distinctive ...flavors and colors and contain a high content of nutrients. They owned relatively high content of vitamins, protein, lipid and reducing sugar, and also contained essential amino acids mostly including glutamic acid, aspartic acid, leucine. Additionally, the mineral content in the fruits also achieved a high level, mainly phosphorus, nitrogen, potassium and magnesium. These obtained findings show that the fruits (persimmon, banana, lemon, longan) are a major source of nutrients as well as essential minerals for humans. The research results are also served as a scientific basis for collecting, processing, preserving and consuming these fruits in Vietnam.
The purpose of this study was to investigate the direct and indirect effects of expectations for marital relationships and premarital sexual permissiveness on intent to marry of Vietnamese emerging ...adults.
Our cross-sectional study was focused on emerging adults including 344 participants, undergraduate students from universities in Viet Nam. This study was assessed by using the PLS-SEM approach.
The main findings demonstrated that (i) sexual orientation have a significant effect on marital intention; (ii) individuals' expectations for marital relationship have a direct effect on marital intention; and (iii) premarital sexuality permissiveness mediates the relationship between expectations for marital relationship and marital intention.
Our results contribute important documents and clearer understanding of emerging adults' expectations and requirements in a relationship for the marriage decision-making process.
This paper presents analysis of geomorphological indices for predicting the maximum observed earthquake (
M
Ob‒Max
) in research region, conducted in three steps: (i) determination of the magnitude ...of completeness (
M
c
) of the study area; (ii) assessment of the sensitivity of the geomorphological indicators (10 indices) to earthquake magnitude prediction; (iii) determination of the
M
Ob–Max
value. With a multilayer perceptron (MLP) neural network model with one hidden layer (10-14-1) and three methods of data sensitivity assessment for neural networks (Garson’s algorithm, Olden’s algorithm, Partial Derivatives method) combined with the simple ranking method, we evaluated the importance of 10 geomorphological indices correlated with earthquake magnitude. We find that group-1 is drainage density index (L) and Slope index (S) (average rank 28.5). Group-2 is the mountain front sinuosity index (S
mf
), drainage basin shape index (B
s
) (average rank 18). The most important group-3 is asymmetry factor index (AF), focal statistics index (ΔGH) and hypsometric integral index (HI) (average rank 13.4). The last group-4 with the lowest earthquake magnitude correlation value includes stream length‒gradient index (SL), valley floor width to height ratio (V
f
), fractal dimension (FD) (average rank 10.7). Using an MLP neural network with one hidden layer (8-18-1) and eight input geomorphological indices (L, S, S
mf
, B
s
, AF, ΔGH, HI, SL), the earthquake prediction within the Cao Bang and neighboring provinces becomes
M
Ob‒Max
= 6.0 and includes the following seven sources: Song (River) Nuoc Den, Song Quay Son, Quang Yen-Song Bang, Cao Bang-Tien Yen, Song Ta Chien, Ha Giang, and Na Hang areas.
Among other fields, climate change has a great influence on metal corrosion that reduces the durability and reliability of steel structures. A time-dependent reliability analysis includes ...time-dependent climate scenarios and deterioration processes as well as random variables, material properties, and dimensions. The extent of corrosion damage is calculated by tracking the evolution of the corrosion process using Monte Carlo simulations. The current paper presents a time-dependent reliability assessment of a continuous I-shaped steel beam, considering the corrosion effects of climate change in Vietnam. The results showed that the safety probability of a continuous steel beam considering metal corrosion from the pristine to 100 years reduces from 96.77% to 63.08%. These findings can be used to assess and provide a cost-technical analysis of climate adaptation measures.
The red-fleshed dragon fruit (Hylocereus polyrhizus) is a popular fruit in tropical countries due to its taste and nutritional value. This study aimed to investigate the physiological and biochemical ...changes during the development and maturation of red-fleshed dragon fruit grown in Vietnam. Fruits were measured for size and content of chlorophyll, carotenoids, reducing sugars, starch, total organic acids, vitamin C, lipids and proteins from 6 to 34 days after anthesis (DAA). The fruits reached a maximum size at 32 DAA. Chlorophyll content increased gradually from fruit formation to 18 DAA, then rapidly decreased until fruit ripening, whereas carotenoid content increased gradually from fruit formation to ripening. Starch and total organic acids contents gradually increased and reached maximum values at 18 and 22 DAA, respectively, and then declined. The contents of reducing sugars, lipids and vitamin C increased as the fruit proceeded towards ripening, reached maximum values at 32 DAA and then declined once the fruit was overripe. Proteins content gradually increased from 6 to 14 DAA and then decreased as the fruit proceeded towards ripening. These results suggest that red-fleshed dragon fruit should be harvested at 32 DAA to maximize the nutritional value and quality of the fruit.
Thyme (Thymus vulgaris L.) has been used for centuries in traditional medicine due to its various health benefits, and it is widely used today in aromatherapy, cosmetics, and even as a culinary herb. ...This study aimed to investigate how the chemical compositions and antimicrobial activity of essential oils extracted from the aerial parts of T. vulgaris were affected by storage at different temperatures. The essential oils were obtained by hydrodistillation of air-dried samples and analyzed using gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). The study observed changes in the essential oil’s composition when stored in a refrigerator (4 °C) and at room temperature (25 °C) for three months. The results revealed that the proportions of compounds with lower boiling temperatures such as β-myrcene (2.29–0.20%) and α-pinene (2.74–0.24%) along with γ-terpinene (7.84–4.81%) and p-cymene (10.93–5.61%) as thymol and carvacrol precursors, were significantly decreased when stored at room temperature. However, the amounts of thymol and carvacrol increased by 51.64 and 21.81%, respectively, after three months storage period, indicating a rise in the oil quality index. Storing the essential oil in a refrigerator resulted in minimal changes to the essential oil composition and maintained its primary quality. In addition, the antimicrobial activity of the essential oils was tested using the broth microdilution method and demonstrated that the essential oils from both storage methods retained their antimicrobial activity compared to freshly extracted ones. In summary, these findings are beneficial for essential oil producers and consumers in the pharmaceutical and cosmetic industries.
Background The BRAF.sup.V600E gene encodes for the mutant BRAF.sup.V600E protein, which triggers downstream oncogenic signaling in thyroid cancer. Since most currently available methods have focused ...on detecting BRAF.sup.V600E mutations in tumor DNA, there is limited information about the level of BRAF.sup.V600E mRNA in primary tumors of thyroid cancer, and the diagnostic relevance of these RNA mutations is not known. Methods Sixty-two patients with thyroid cancer and non-malignant thyroid disease were included in the study. Armed with an ultrasensitive technique for mRNA-based mutation analysis based on a two step RT-qPCR method, we analysed the expression levels of the mutated BRAF.sup.V600E mRNA in formalin-fixed paraffin-embedded samples of thyroid tissues. Sanger sequencing for detection of BRAF.sup.V600E DNA was performed in parallel for comparison and normalization of BRAF.sup.V600E mRNA expression levels. Results The mRNA-based mutation detection assay enables detection of the BRAF.sup.V600E mRNA transcripts in a 10,000-fold excess of wildtype BRAF counterparts. While BRAF.sup.V600E mutations could be detected by Sanger sequencing in 13 out of 32 malignant thyroid cancer FFPE tissue samples, the mRNA-based assay detected mutations in additionally 5 cases, improving the detection rate from 40.6 to 56.3%. Furthermore, we observed a surprisingly large, 3-log variability, in the expression level of the BRAF.sup.V600E mRNA in FFPE samples of thyroid cancer tissue. Conclusions The expression levels of BRAF.sup.V600E mRNA was characterized in the primary tumors of thyroid cancer using an ultrasensitive mRNA-based mutation assay. Our data inspires further studies on the prognostic and diagnostic relevance of the BRAF.sup.V600E mRNA levels as a molecular biomarker for the diagnosis and monitoring of various genetic and malignant diseases. Keywords: Thyroid cancer, BRAF mutation, mRNA mutation assay, Diagnosis
Tomato (Solanum lycopersicum L.) is one of the most widely grown and consumed vegetables in many countries, including Vietnam. Tomato is a nutritious food that enhances the body's resistance. This ...paper presents research results on some physiological indicator (pigments content), and biochemical indicators (reducing sugar content, starch, total organic acid, vitamin C, pectin, tannin, α-amylase enzyme, catalase enzyme, peroxidase enzyme) of tomatoes during growth and ripening cultivated in Vietnam, thereby determining the physiological ripening time of the fruit (the most appropriate time for fruit harvest). The results showed that significant changes occurred in pigments content, reducing sugar content, starch, total organic acid, vitamin C, pectin, tannin, α-amylase enzyme, catalase enzyme, peroxidase enzyme of tomatoes from formation to fruit ripening. Through the research process, we found that tomatoes achieve the best quality to harvest when fruits are 46 days old. The results of this study also provide additional and useful information for fresh consumption and processing as well as the use of tomatoes.
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