Silver nanoparticles loaded on lactose/alginate: in situ synthesis, catalytic degradation, and pH-dependent antibacterial activity.

We present the in situ synthesis of silver nanoparticles (AgNPs) through ionotropic gelation utilizing the biodegradable saccharides lactose (Lac) and alginate (Alg). The lactose reduced silver ions to form AgNPs. The crystallite structure of the nanocomposite AgNPs@Lac/Alg, with a mean size of 4-6 nm, was confirmed by analytical techniques. The nanocomposite exhibited high catalytic performance in degrading the pollutants methyl orange and rhodamine B. The antibacterial activity of the nanocomposite is pH-dependent, related to the alterations in surface properties of the nanocomposite at different pH values. At pH 6, the nanocomposite demonstrated the highest antibacterial activity. These findings suggest that this nanocomposite has the potential to be tailored for specific applications in environmental and medicinal treatments, making it a highly promising material.

Microplastics and trace metals in river sediment: Prevalence and correlation with multiple factors.

Microplastics (MPs), which are ubiquitous, are no longer novel emerging pollutants, yet our knowledge of them is insufficient. This study investigates the prevalence of MPs and trace metals in sediment belonging to Ma River, Vietnam, and their interaction with various parameters, including nutrients such as total carbon (TC), total nitrogen (TN), and total phosphorus (TP), grain sizes, and MPs in surface water. The study revealed that the abundance of MPs in sediment (MPs/S) is relatively high (i.e., 1328.3 ± 1925.5 items.kg-1 dry weight), while the concentration of MPs in surface water (MPs/W) was relatively low (i.e., 57.3 ± 55.8 items.m-3) compared to other areas. Notably, the study found that arsenic and cadmium concentrations exceeded baseline levels, indicating their anthropogenic origin. To interpret the relationship between MPs/S, metals, and the aforementioned parameters, principal component analysis and Pearson correlation analyses were employed. The results demonstrated a significant correlation between metals and nutrients, as well as small grain sizes such as clay and silt. It was observed that the majority of metals displayed co-occurrence with one another but showed weak associations with the levels of MPs present in both water and sediment. Additionally, a weak correlation was observed between MPs/W and MPs/S. In conclusion, these findings suggest that the distribution and behavior of MPs and trace metals in aquatic systems are influenced by multiple factors, including nutrient levels, grain size, and other chemical and physical characteristics of the environment. While certain metals may have natural sources, others may result from human activities such as mining, industrial discharge, and wastewater treatment plants. As a result, understanding the sources and aspects of metal contamination are critical for determining their relationship with MPs and developing effective strategies for mitigating their impact on aquatic ecosystems.

A study assessing the impact of income relative deprivation and cooperative membership on rural residents' health: A pathway towards improving the health status of rural residents.

Rural residents' health status is related to their happiness, socioeconomic status, personal development, and the ideals of living, but individual income relative deprivation has a negative impact on their health. Hence, this study aimed to examine that how to alleviate the negative impact of income relative deprivation on rural residents' health. Based on a literature review, it is the first study to propose that cooperative membership could help alleviate the adverse effects of income relative deprivation on rural residents' health. It survey data from 466 farm households in Shandong Province in China and employs an endogenous switching probit model to solve the endogenous problems. The results show that relative deprivation positively affects farmers' membership in a cooperative but negatively impacts their health. More importantly, the results indicate that membership in a cooperative improves farmers' health and alleviates the adverse effects of relative deprivation. These findings not only expand the empirical research on the positive impact of relative deprivation but also provide a new pathway towards improving the negative impact of income relative deprivation on rural residents' health. That is, the government should guide smallholder farmers to join professional cooperatives and encourage the development of 'multi-functional' cooperatives to play a greater role in improving rural residents' health.

A study evaluating the extrinsic and intrinsic determinants of farmers' adoption of climate change adaptation strategies: A novel approach for improving farmers' health.

Small-scale farmers living in mountainous areas are particularly vulnerable to climate change. Although governments have implemented various support programs and policies to support a range of farmers to tackle climatic changes, there are still several difficulties in the implementation of these adaptation strategies. Using the survey data of 758 small-scale farmers this paper employs Multivariate Probit (MVP) and Poisson regression models to measure the effects of intrinsic and extrinsic factors affecting farmers adaptation decision in rural Vietnam. The results reveal that the extrinsic factors such as annual rainfall variations and farm size motivate farmers' adoption of their adaptations. The findings also reveal that the political connection has a significantly positive impact on the respondents' selection, while government interference such as extension training programs has a negative association with the farmers adaptation choice. Public extension programs should be simultaneously redesigned to support farmers in mitigating the impacts of climate change.

Analyzing the status of multidimensional poverty of rural households by using sustainable livelihood framework: policy implications for economic growth.

Poverty is a multifaceted and location-based issue that cannot be quantified using monetary metrics alone. This study aims to evaluate the multidimensional poverty status of poor households in Ha Giang province, Vietnam, by using the DFID (Department for International Development) sustainable livelihood framework, an integrating technique for spatial recognition of multidimensional poverty, was developed and deployed to conduct a county-level poverty assessment in rural Vietnam. The multidimensional poverty standard is considered a novel approach to assess poverty, identify causes of poverty, and encourage poor households to sustainably escape poverty. A household survey was conducted in three rural districts, namely Dong Van, Hoang Su Phi, and Bac Quang in Ha Giang province, Vietnam, during 2016 to 2021. The results of the study show that surveyed households are deficient in all five main sources of livelihood, in which the three most deficient capital sources are natural capital, social capital, and financial capital. The findings revealed that the majority of farming households were classified as multidimensionally poor. The multidimensionally poor regions were not only poorer in single-dimensional and aggregate ratings than the income-poor and recognized poor regions, but they also had several vulnerabilities and insecurity. The assessment of multidimensional poverty, by distinguishing the poor, marginalized, and dispossessed dimensions, should be extremely beneficial for each region to design and execute poverty reduction programs accordingly, and it would contribute to improving the persistence of alleviating poverty. The article also proposes a number of sustainable poverty reduction measures, in which the root is to improve the spirit of self-raising to escape poverty of households.

High-efficient reduction of methylene blue and 4-nitrophenol by silver nanoparticles embedded in magnetic graphene oxide.

In this study, a ternary magnetically separable nanocomposite of silver nanoparticles (AgNPs) embedded in magnetic graphene oxide (Ag/Fe3O4@GO) was designed and synthesized. Beta-cyclodextrin was used as a green reducing and capping agent for decorating of AgNPs on Fe3O4@GO. The fabricated material was characterized using X-ray diffractometry, Fourier transform infrared spectroscopy, scanning electron microscopy, vibrating sample magnetometry, and energy-dispersive X-ray spectroscopy. The catalytic properties of the prepared Ag/Fe3O4@GO for the reduction of 4-nitrophenol (4-NP) and methylene blue (MB) dye with sodium borohydride were investigated in detail. The morphological and structural studies revealed that Fe3O4 and AgNPs with a mean size of 12 nm were uniformly distributed on the GO sheet at high densities. The catalytic tests showed that Ag/Fe3O4@GO exhibited an ultrafast catalytic reduction of 4-NP and MB with a reduction rate constant of 0.304 min-1 and 0.448 min-1, respectively. Moreover, the catalyst demonstrated excellent stability and reusability, as evidenced by the more than 97% removal efficiency maintained after five reuse cycles. The Ag/Fe3O4@GO catalyst could be easily recovered by the magnetic separation due to the superparamagnetic nature of Fe3O4 with high saturated magnetization (45.7 emu/g). Besides, the formation of networking between the formed AgNPs and ß-CD through hydrogen bonding prevented the agglomeration of AgNPs, ensuring their high catalytic ability. The leaching study showed that the dissolution of Fe and Ag from Ag/Fe3O4@GO was negligible, indicating the environmental friendliness of the synthesized catalyst. Finally, the high catalytic performance, excellent stability, and recoverability of Ag/Fe3O4@GO make it a potential candidate for the reduction of organic pollutants in wastewater.

Highly sensitive and low-cost colourimetric detection of glucose and ascorbic acid based on silver nanozyme biosynthesized by Gleditsia australis fruit.

In this study, a simple, eco-friendly and low-cost approach was used to fabricate silver nanoparticles (AgNPs) from an aqueous extract of Gleditsia australis (GA) fruit. The nanoparticles synthesized in the optimal condition have an average size of 14 nm. The peroxidase-like activity of GA-AgNP in the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) in combination with hydrogen peroxide (H2O2) was investigated. Further, optimal conditions for the use of peroxidase-like catalytic activity in sensing applications were identified. The colourimetric detection of H2O2 showed a linear range of 1-8 mM with a limit of detection (LOD) of 0.34 mM. The oxidation of TMB (red-TMB) enables the detection of glucose, which is converted into H2O2 and gluconic acid in the presence of the enzyme glucose oxidase. The observations showed linearity from 0.05 to 1.5 mM with a LOD of 0.038 mM. Moreover, the blue colour of oxidized TMB (ox-TMB) was reduced according to ascorbic acid (AA) concentration, with a linear range of 0.03-0.14 mM and a LOD of 3.0 µM. The practical use of the sensing system for the detection of AA was studied using real fruit juice and showed good sensitivity. Hence, the easy-to-use peroxidase-like sensor provides a new platform for the detection of bioactive compounds in biological systems.

Assessment of farm households' perception, beliefs and attitude toward climatic risks: A case study of rural Vietnam.

Vietnam is one the most vulnerable region to climate change and extreme climatic events, such as flash floods and droughts. This present research aims to explore the farm households' beliefs, risk perception, adaptive attitude and climate change adaptation measures that they currently utilize in their farms to cope with climatic risks. Further, this study analyzed effect of climate change belief, awareness and adaptive attitudes on farmers' adaptive behavior. By using structured questionnaire, the data from 816 respondents were collected from seven provinces of Vietnam. We used ordinary least squares regression and logistic regression approach to analyze farmers' belief, perception of climatic change, and risk attitude towards climatic hazards. Results revealed that farmers in the study area are using the most common climatic risk management strategies including applying new technologies, adjustment of the seasonal calendar, and diversification. Findings further revealed that that farm households were mostly concerned about the risk in soil erosion and washout, followed by the stress of prolonging dry season and droughts. The study participants also reported a decrease in precipitation and increase in temperature and frequency and incidence of other extreme climatic events. A positive significant relationship was found between farm management practices and ecological communities. Risk perceptions and attitude toward climate change are essential factors among farm households of northern mountains of Vietnam. Thus, the climate strain linked with the institutional stress and socio-economic has serious insinuations for farm households' livelihood bases, a universal climate change adaptation scheme is required to endure farmers' livelihood.

Fabrication of Fe3O4/CuO@C composite from MOF-based materials as an efficient and magnetically separable photocatalyst for degradation of ciprofloxacin antibiotic.

In this work, a novel ternary Fe3O4/CuO@C composite was fabricated using iron-doped copper 1,4-benzenedicarboxylate metal-organic frameworks as a self-sacrificing template. The morphological, structural, and optical properties of the prepared composite were determined by various techniques, and its photocatalytic behavior was investigated for degradation of ciprofloxacin under visible light irradiation. The Fe3O4/CuO@C material presented a porous structure with a rough surface of about 4-20 µm, and was composed of the Fe3O4/CuO nanocomposite uniformly distributed on a carbon support. The band gap energy of the obtained composite was found to be 2.0 eV, which was nearly two times lower than that of Fe3O4@C and CuO@C. As a result, Fe3O4/CuO@C exhibited high photocatalytic activity, achieving a degradation efficiency of 98.5% after 120 min irradiation at the optimum conditions (a catalyst dosage of 0.5 g L-1, pH of 7, CIP concentration of 15 mg L-1). The mechanism of ciprofloxacin degradation by Fe3O4/CuO@C was elucidated with the main contribution of O2-and OH reactive radicals. The new composite catalyst could easily be recovered from the treated solution using an external magnetic field due to its superparamagnetic nature. Fe3O4/CuO@C also showed good reusability and stability. The overall results indicated that the synthesized composite has significant application potential for controlling the risk of antibiotics in wastewater.

Utilizing waste corn-cob in biosynthesis of noble metallic nanoparticles for antibacterial effect and catalytic degradation of contaminants.

In the present study, cost-effective, and environmentally friendly fabrication of silver and gold nanoparticles was performed by using aqueous extract of waste corn-cob. The formation of the metallic nanoparticles (MNPs) was optimized by UV-Vis method. The phytoconstituents were responsible for reduction of silver and gold ions to silver nanoparticles (CC-AgNPs) and gold nanoparticles (CC-AuNPs) which were demonstrated by Fourier-transform infrared (FTIR) spectroscopy while formation of AgCl was attributed to the presence of chloride ions in the aqueous extract. The crystalline nature of the AgNPs, AgCl, and AuNPs was confirmed using the X-ray diffraction (XRD) and selected area electron diffraction (SAED) patterns. Morphological studies showed that the synthesized CC-AgNPs existed in spherical shape with the size ranging from 2 to 28 nm possessing an average value of 11 nm while CC-AuNPs were present in the multiple shapes with size ranging from 5 to 50 nm possessing an average value of 35 nm. For studies on bioactive application, the CC-AgNPs exhibited a high antibacterial activity against three bacterial strains including Salmonella typhimurium, Bacillus cereus, and Staphylococcus aureus. In addition, the catalytic efficiency of MNPs was investigated for reduction of o-, m-, p-nitrophenols, and degradation of organic dyes including Eosin Y and Rhodamine 6G. The rate constants calculated from the kinetical data revealed that the biosynthesized nanoparticles are excellent catalysts in potential applications for treatment of wastewater. Graphical abstract .

Reaction kinetics of substrate transglycosylation catalyzed by TreX of Sulfolobus solfataricus and effects on glycogen breakdown.

We studied the activity of a debranching enzyme (TreX) from Sulfolobus solfataricus on glycogen-mimic substrates, branched maltotetraosyl-ß-cyclodextrin (Glc4-ß-CD), and natural glycogen to better understand substrate transglycosylation and the effect thereof on glycogen debranching in microorganisms. The validation test of Glc4-ß-CD as a glycogen mimic substrate showed that it followed the breakdown process of the well-known yeast and rat liver extract. TreX catalyzed both hydrolysis of α-1,6-glycosidic linkages and transglycosylation at relatively high (>0.5 mM) substrate concentrations. TreX transferred maltotetraosyl moieties from the donor substrate to acceptor molecules, resulting in the formation of two positional isomers of dimaltotetraosyl-α-1,6-ß-cyclodextrin [(Glc4)2-ß-CD]; these were 6(1),6(3)- and 6(1),6(4)-dimaltotetraosyl-α-1,6-ß-CD. Use of a modified Michaelis-Menten equation to study substrate transglycosylation revealed that the kcat and Km values for transglycosylation were 1.78 × 10(3) s(-1) and 3.30 mM, respectively, whereas the values for hydrolysis were 2.57 × 10(3) s(-1) and 0.206 mM, respectively. Also, enzyme catalytic efficiency (the kcat/Km ratio) increased as the degree of polymerization of branch chains rose. In the model reaction system of Escherichia coli, glucose-1-phosphate production from glycogen by the glycogen phosphorylase was elevated ∼1.45-fold in the presence of TreX compared to that produced in the absence of TreX. The results suggest that outward shifting of glycogen branch chains via transglycosylation increases the number of exposed chains susceptible to phosphorylase action. We developed a model of the glycogen breakdown process featuring both hydrolysis and transglycosylation catalyzed by the debranching enzyme.