Mesoporous Gold: Substrate-Dependent Growth Dynamics, Strain Accumulation, and Electrocatalytic Activity for Biosensing.

Understanding the growth of mesoporous crystalline materials, such as mesoporous metals, on different substrates can provide valuable insights into the crystal growth dynamics and the redox reactions that influence their electrochemical sensing performance. Herein, it is demonstrated how the amorphous nature of the glass substrate can suppress the typical <111> oriented growth in mesoporous Au (mAu) films. The suppressed <111> growth is manifested as an accumulation of strain, leading to the generation of abundant surface defects, which are beneficial for enhancing the electrochemical activity. The fine structuring attained enables dramatically accelerated diffusion and enhances the electrochemical sensing performance for disease-specific biomolecules. As a proof-of-concept, the as-fabricated glass-grown mAu film demonstrates high sensitivity in electrochemical detection of SARS-CoV-2-specific RNA with a limit of detection (LoD) as low as 1 attomolar (aM).

Cytotoxic and Bactericidal Effects of Inhalable Ciprofloxacin-Loaded Poly(2-ethyl-2-oxazoline) Nanoparticles with Traces of Zinc Oxide.

The bactericidal effects of inhalable ciprofloxacin (CIP) loaded-poly(2-ethyl-2-oxazoline) (PEtOx) nanoparticles (NPs) with traces of zinc oxide (ZnO) were investigated against clinical strains of the respiratory pathogens Staphylococcus aureus and Pseudomonas aeruginosa. CIP-loaded PEtOx NPs retained their bactericidal activity within the formulations compared to free CIP drugs against these two pathogens, and bactericidal effects were enhanced with the inclusion of ZnO. PEtOx polymer and ZnO NPs did not show bactericidal activity alone or in combination against these pathogens. The formulations were tested to determine the cytotoxic and proinflammatory effects on airway epithelial cells derived from healthy donors (NHBE), donors with chronic obstructive pulmonary disease (COPD, DHBE), and a cell line derived from adults with cystic fibrosis (CFBE41o-) and macrophages from healthy adult controls (HCs), and those with either COPD or CF. NHBE cells demonstrated maximum cell viability (66%) against CIP-loaded PEtOx NPs with the half maximal inhibitory concentration (IC50) value of 50.7 mg/mL. CIP-loaded PEtOx NPs were more toxic to epithelial cells from donors with respiratory diseases than NHBEs, with respective IC50 values of 0.103 mg/mL for DHBEs and 0.514 mg/mL for CFBE41o- cells. However, high concentrations of CIP-loaded PEtOx NPs were toxic to macrophages, with respective IC50 values of 0.002 mg/mL for HC macrophages and 0.021 mg/mL for CF-like macrophages. PEtOx NPs, ZnO NPs, and ZnO-PEtOx NPs with no drug were not cytotoxic to any cells investigated. The in vitro digestibility of PEtOx and its NPs was investigated in simulated lung fluid (SLF) (pH 7.4). The analysed samples were characterized using Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), and UV-Vis spectroscopy. Digestion of PEtOx NPs commenced one week following incubation and was completely digested after four weeks; however, the original PEtOx was not digested after six weeks of incubation. The outcome of this study revealed that PEtOx polymer could be considered an efficient drug delivery carrier in respiratory linings, and CIP-loaded PEtOx NPs with traces of ZnO could be a promising addition to inhalable treatments against resistant bacteria with reduced toxicity.

Advancing Catalysts by Nanoconfinement and Catalysis for Enhanced Hydrogen Production from Magnesium Borohydride: A Review.

Hydrogen storage in solid-state materials represents a highly promising avenue for advancing hydrogen storage technologies, driven by their potential for high efficiency, reduced risk, and cost-effectiveness. Among these materials, magnesium borohydride (Mg(BH4)2), hereafter denoted as MBH, stands out for its exceptional characteristics, boasting a gravimetric capacity of 14.9 wt% and a volumetric hydrogen density capacity of 146 kg/m3. However, the practical application of MBH is impeded by challenges such as high desorption temperatures (≥ 270°C), sluggish kinetics, poor reversibility, and the formation of unexpected byproducts like diborane. To meet  these, extensive research efforts have been directed towards enhancing the hydrogen storage properties of MBH. This review provides a comprehensive survey of recent advancements in MBH research, with a particular focus on experimental findings related to nanoconfined MBH and modified thermodynamic processes aimed at enabling hydrogen release at lower temperatures by mitigating sluggish kinetics. Specifically, nanostructuring techniques, catalyst-mediated nanoconfinement methodologies, and alloy/compositional modifications will be elucidated, highlighting their potential to enhance hydrogen storage properties and overcome existing limitations. Furthermore, this review discusses the challenges encountered in the utilization of MBH for hydrogen storage applications and offers insights into the future prospects of this material.

Nutritional value of the marine fish in Bangladesh and their potential to address malnutrition: A review.

Marine fish are good source of essential macro- and micronutrients and major food items in coastal areas in Bangladesh. However, there is no review that details the nutritional value of marine fish in Bangladesh. Therefore, this review focuses on the nutrient composition of marine fish in Bangladesh and how the marine fish can address common nutrient deficiencies among women and children. Nutrient composition data was collected through literature searching in databases and source, including PubMed, Web of Science, Google Scholar, ScienceDirect, WorldFish, and Bangladesh-based database Banglajol. Calculation was carried out to present how one serving marine fish could potentially meet the daily requirement of protein, iron, zinc, calcium, vitamin A, and docosahexaenoic acid (DHA) for pregnant and lactating women and children aged 6-23 months. A total of 97 entries covering nutrient composition analysis of 67 individual fish species were extracted from 12 articles published between 1993 and 2020. Included articles contained analysis of proximate composition, vitamins, minerals, fatty acids, and amino acid. Twelve minerals and nine vitamins were analyzed and reported. The average energy, protein, fat, and ash content per 100 g edible raw marine fish was 343.58 kJ, 16.76 g, 4.16 g, and 2.22 g, respectively. According to available data, marine fish are good sources of protein, zinc, calcium, and DHA. Pelagic small fish, which are mainly captured by artisanal small-scale fishers, had more nutritional value than other categories of fish. Furthermore, marine small fish were found more nutritious than commonly consumed freshwater fish types in Bangladesh, including major carps, introduced carps, and tilapia. Therefore, the study concludes that marine fish have high potential to address malnutrition in Bangladesh. There was scarcity of literature regarding the nutrient composition of marine fish in Bangladesh and in South Asia as a whole, so more comprehensive quality research in this area is recommended.

Boosting capacitive performance of manganese oxide nanorods by decorating with three-dimensional crushed graphene.

This work reports the rational design of MnOx nanorods on 3D crushed reduced graphene oxide (MnOx/C-rGO) by chemical reduction of Ni-incorporated graphene oxide (GO) followed by chemical etching to remove Ni. The resulting MnOx/C-rGO composite synergistically integrates the electronic properties and geometry structure of MnOx and 3D C-rGO. As a result, MnOx/C-rGO shows a significantly higher specific capacitance (Csp) of 863 F g-1 than MnOx/2D graphene sheets (MnOx/S-rGO) (373 F g-1) and MnOx (200 F g-1) at a current density of 0.2 A g-1. Furthermore, when assembled into symmetric supercapacitors, the MnOx/C-rGO-based device delivers a higher Csp (288 F g-1) than MnOx/S-rGO-based device (75 F g-1) at a current density of 0.3 A g-1. The superior capacitive performance of the MnOx/C-rGO-based symmetric device is attributed to the enlarged accessible surface, reduced lamellar stacking of graphene, and improved ionic transport provided by the 3D architecture of MnOx/C-rGO. In addition, the MnOx/C-rGO-based device exhibits an energy density of 23 Wh kg-1 at a power density of 113 Wkg-1, and long-term cycling stability, demonstrating its promising potential for practical application.

Dominant phytoplankton groups as the major source of polyunsaturated fatty acids for hilsa (Tenualosa ilisha) in the Meghna estuary Bangladesh.

The tropical estuarine ecosystem is fascinating for studying the dynamics of water quality and phytoplankton diversity due to its frequently changing hydrological conditions. Most importantly, phytoplankton is the main supplier of ω3 polyunsaturated fatty acids (PUFA) in the coastal food web for fish as they could not synthesize PUFA. This study evaluated seasonal variations of water quality parameters in the Meghna River estuary (MRE), explored how phytoplankton diversity changes according to hydro-chemical parameters, and identified the major phytoplankton groups as the main source of PUFA for hilsa fish. Ten water quality indicators including temperature, dissolved oxygen, pH, salinity, dissolved inorganic nitrogen (DIN = nitrate, nitrite, ammonia) and phosphorus, dissolved silica and chlorophyll-a were evaluated. In addition, phytoplankton diversity was assessed in the water and hilsa fish gut. Principal component analysis (PCA) was used to analyze the spatio-temporal changes in the water quality conditions, and the driving factors in the MRE. Four main components were extracted and explained 75.4% variability of water quality parameters. The most relevant driving factors were dissolved oxygen, salinity, temperature, and DIN (nitrate, nitrite and ammonia). These variabilities in physicochemical parameters and dissolved inorganic nutrients caused seasonal variations in two major groups of phytoplankton. Peak abundance of Chlorophyta (green algae) occurred in water in nutrient-rich environments (nitrogen and phosphorus) during the wet (36%) season, while Bacillariophyta (diatoms) were dominant during the dry (32%) season that depleted dissolved silica. Thus, the decrease of green algae and the increase of diatoms in the dry season indicated the potential link to seasonal changes of hydro-chemical parameters. The green algae (53.7%) were the dominant phytoplankton group in the hilsa gut content followed by diatoms (22.6%) and both are contributing as the major source of PUFAs for hilsa fish according to the electivity index as they contain the highest amounts of PUFAs (60 and 28% respectively).

Silver Micro-Nanoparticle-Based Nanoarchitectures: Synthesis Routes, Biomedical Applications, and Mechanisms of Action.

Silver has become a potent agent that can be effectively applied in nanostructured nanomaterials with various shapes and sizes against antibacterial applications. Silver nanoparticle (Ag NP) based-antimicrobial agents play a major role in different applications, including biomedical applications, as surface treatment and coatings, in chemical and food industries, and for agricultural productivity. Due to advancements in nanoscience and nanotechnology, different methods have been used to prepare Ag NPs with sizes and shapes reducing toxicity for antibacterial applications. Studies have shown that Ag NPs are largely dependent on basic structural parameters, such as size, shape, and chemical composition, which play a significant role in preparing the appropriate formulation for the desired applications. Therefore, this review focuses on the important parameters that affect the surface interaction/state of Ag NPs and their influence on antimicrobial activities, which are essential for designing future applications. The mode of action of Ag NPs as antibacterial agents will also be discussed.

Enhanced biodiversity of gut flora and feed efficiency in pond cultured tilapia under reduced frequency feeding strategies.

Feed constitutes 50-70% of total production costs of tilapia, one of the most widely cultured finfishes in the world. We evaluated reduced-feeding strategies for improving production efficiency of Nile tilapia (Oreochromis niloticus). In a 12-week pond trial, fish were fed daily, every other day, every third day, or not at all. Ponds were fertilized to enhance natural foods. In a fifth group fish were fed daily without pond fertilization. Fish fed daily with or without pond fertilization and fish fed every other day had higher specific growth rates, survivability, and net production than the other two treatments. Fish feed efficiency and benefit to cost ratio was highest for treatments fed in a pulsatile manner (i.e. fed every other day or every third day) with fish fed on alternate days providing the best net return among all groups. Fish fed on alternate days had more moderate gene expression levels of intestinal nutrient transporters which may allow for a more balanced and efficient nutrient uptake. Fecal microbe analyses identified 145 families of prokaryotic and 132 genera of eukaryotic organisms in tilapia. The highest diversity of prokaryotes was found in fish fed either every other day or daily in fertilized ponds and the highest diversity of eukaryotes was found in fish fed every other day. These studies indicate feeding Nile tilapia on alternate days along with weekly pond fertilization has no deleterious effects on growth, survivability, or production versus daily feeding regimes, but enhances feed efficiency by 76% and provides the greatest net return on investments. Our studies also suggest for the first time that combining alternate-day feeding with pond fertilization produces the greatest microbial biodiversity in the intestine that could contribute to enhanced feed efficiency and overall health of tilapia.

Reproductive Biology and Ecology of the Green Mussel Perna viridis: A Multidisciplinary Approach.

A multidisciplinary approach was applied to explore deeper knowledge about the reproductive biology and ecology of the green mussel (Perna viridis) by interlinking among ecological factors, ingested gut plankton, gonad fatty acid profile, and reproductive traits. Mussels were collected throughout the year from the coastal region of the Bay of Bengal of Bangladesh, and the histological analysis of 242 mussels revealed five stages of gametogenesis with an annual spawning season from January to April. The gonadosomatic index showed a strong correlation with the water quality parameters, ingested gut plankton groups, and gonadal fatty acids, and also displayed prominent effects of seasonality. In all datasets, we performed principal component analysis in which the first two principal components showed that seasonality explained >65% of the variability, and the multivariate spaces of seasonality corresponded to the gonad development. High salinity, nutrients, chlorophyll a, and plankton abundance in the water column were positively correlated with gonad development and the spawning of mussels. During the development stage, mussel ingested more plankton, particularly Bacillariophyceae and Pyrrophyceae, which were an important source of increased n-3 polyunsaturated fatty acids content in gonads. Furthermore, gonads accumulated more lipids and saturated fatty acids during the mature and spawning stages, which were probably utilized during embryogenesis and early larval development as energy sources and constituents of the cell membrane. This research provides a model toward a better understanding of reproductive biological traits and how these traits are interrelated with the surrounding environmental variables of the green mussel, which would be helpful in marine aquaculture and the sustainable exploitation of the fishery resources.

Understanding Social-Ecological Challenges of a Small-Scale Hilsa (Tenualosa ilisha) Fishery in Bangladesh.

Small-scale fisheries (SSFs) have been playing a crucial role in meeting the basic needs of millions of people around the world. Despite this, the sustainability of global fisheries is a growing concern, and the factors enabling or constraining the sustainable management of small-scale fisheries remain poorly understood. Hilsa shad (Tenualosa ilisha) is the single most valuable species harvested in Bangladesh waters, serves nutrition, income, and employment to the large population. This study analyzed the state and challenges of hilsa fishery in the Gangetic River systems (Padma and Meghna Rivers) by using two frameworks, namely the social-ecological systems (SES) and drivers-pressure-state-impact-responses (DPSIR) frameworks. Primary data for this analysis were collected by in-depth interviews (n = 130) and focus group discussions (n = 8) with various stakeholders in the hilsa fisheries. The perspectives explored here have been both critical and constructive, including the identification of problems and suggestions for improving the management of this particular social-ecological system. Hilsa fisheries, however, have come under severe threat since 2003 because of population growth, overfishing, pollution, climate change, the disruption of migration routes due to siltation, etc. All these have caused reduced catches and less stable incomes for fishers. This, in turn, has led to poverty, malnutrition, social tensions, stakeholder conflicts, and debt cycles amongst more impoverished fishing communities. These problems have been compounded by improved fishing technology amongst larger-scale ventures, the use of illegal fishing gears, and the non-compliance of government fishery management programs. Recommendations include the promotion of community-supported fisheries, the enhancement of stakeholder's social resilience, the introduction of co-management approach, an increase in incentives and formal financial supports, and possible community-managed sustainable ecotourism including hilsa fishing-based tourism.

Population Genomics of an Anadromous Hilsa Shad Tenualosa ilisha Species across Its Diverse Migratory Habitats: Discrimination by Fine-Scale Local Adaptation.

The migration of anadromous fish in heterogenic environments unceasingly imposes a selective pressure that results in genetic variation for local adaptation. However, discrimination of anadromous fish populations by fine-scale local adaptation is challenging because of their high rate of gene flow, highly connected divergent population, and large population size. Recent advances in next-generation sequencing (NGS) have expanded the prospects of defining the weakly structured population of anadromous fish. Therefore, we used NGS-based restriction site-associated DNA (NextRAD) techniques on 300 individuals of an anadromous Hilsa shad (Tenualosa ilisha) species, collected from nine strategic habitats, across their diverse migratory habitats, which include sea, estuary, and different freshwater rivers. The NextRAD technique successfully identified 15,453 single nucleotide polymorphism (SNP) loci. Outlier tests using the FST OutFLANK and pcadapt approaches identified 74 and 449 SNPs (49 SNPs being common), respectively, as putative adaptive loci under a divergent selection process. Our results, based on the different cluster analyses of these putatively adaptive loci, suggested that local adaptation has divided the Hilsa shad population into two genetically structured clusters, in which marine and estuarine collection sites were dominated by individuals of one genetic cluster and different riverine collection sites were dominated by individuals of another genetic cluster. The phylogenetic analysis revealed that all the riverine populations of Hilsa shad were further subdivided into the north-western riverine (turbid freshwater) and the north-eastern riverine (clear freshwater) ecotypes. Among all of the putatively adaptive loci, only 36 loci were observed to be in the coding region, and the encoded genes might be associated with important biological functions related to the local adaptation of Hilsa shad. In summary, our study provides both neutral and adaptive contexts for the observed genetic divergence of Hilsa shad and, consequently, resolves the previous inconclusive findings on their population genetic structure across their diverse migratory habitats. Moreover, the study has clearly demonstrated that NextRAD sequencing is an innovative approach to explore how dispersal and local adaptation can shape genetic divergence of non-model anadromous fish that intersect diverse migratory habitats during their life-history stages.

Seed supply for coastal brackishwater shrimp farming: environmental impacts and sustainability.

Globally, shrimp farming has been a significant agro-based economic activity since the early 1970s. Because it offered a huge immediate economic return, shrimp farming showed a booming expansion and soon became a multimillion dollar industry. However, it has been under extreme criticism because of its devastating ecological and socio-economic impacts. Because seed is the primary input, the impact from farming has started from the source of seed supply, so that not only are natural stocks of shrimp seeds now overexploited worldwide but seed collection activities also significantly reduce stocks of other living resources. Although hatcheries were developed as potential alternative and have replaced the natural seed source to a great extent, large-scale hatchery productions provide a potential source of coastal pollution. However, this area is still poorly studied. The present paper provides a review of the environmental impacts of the wild shrimp seed fishery as well as the possibility of environmental degradation from artificial shrimp seed production in hatcheries.

The role of fish in food-based strategies to combat vitamin A and mineral deficiencies in developing countries.

Fish is important in the diets and livelihoods of many poor people suffering from vitamin and mineral deficiencies. In this article, fish intake in rural Bangladesh and Cambodia and the vitamin A, calcium, iron, and zinc contents and nutrient bioavailability of commonly consumed species are presented. The contribution of these species to nutrient intakes as well as their potential to meet dietary recommendations are presented and discussed. Data from consumption surveys were analyzed to obtain fish intake by species. Commonly consumed species were analyzed for nutrient contents, and studies on nutrient bioavailability were conducted. In poor, rural, Bangladeshi households, mean fish intake was 13-83 g raw, whole fish per person/d. Frequency of intake of small fish was high, and small fish made up 50-80% of all fish eaten during the fish production season in rural Bangladesh and Cambodia. Many small fish are eaten whole and therefore are a rich calcium source; some are also rich in vitamin A, iron, and zinc. Even small production of the vitamin A-rich fish mola in ponds in Bangladesh can meet the annual vitamin A recommendation of 2 million children, and a traditional daily meal with the iron-rich fish trey changwa plieng can meet 45% of the daily median iron requirement of Cambodian women. Fish consumption data on the species level, nutrient analyses, awareness of the nutritional value of fish, as well as promotion of the production and accessibility of nutrient-dense species can lead to the use of fish in food-based strategies to combat nutrient deficiencies in poor people in Asia and Africa.

Effects of iso-nutrient fertilization on plankton production in earthen ponds of Bangladesh.

The experiment was conducted to evaluate the effects of iso-nutrients fertilization on fertilizer combinations, containing a similar amount of nitrogen (N) and phosphorus (P) were the production of plankton in earthen ponds for a period of eight weeks. Two different were tested in triplicate using six earthen ponds of 100 m2 each. The fertilizer combinations of cow manure, urea and Triple Super Phosphate (TSP) at the rate 5000, 125 and 100 kg ha(-1), respectively, containing approximately 102 kg N and 65 kg P was used for treatment-1 (T-l). Another combination of poultry-manure, urea and TSP at the rate of 2000, 125 and 100 kg ha(-1), respectively, was considered as the treatment-2 (T-2). The application rate of poultry manure was adjusted to make the nutrient (N and P) content of fertilizer combination in T-2 similar to that in T-1. Four groups of phytoplankton namely, Bacillariophyceae, Chlorophyceae, Cyanophyceae and Euglenophyceae and two groups of zooplankton namely, Crustacea and Rotifera were identified. The mean abundance of both phytoplankton (78.25 +/- 6.33 x 10(4) cells L(-1)) and zooplankton (57.63 +/- 4.59 x 10(4) cells L(-1)), were significantly higher (p < 0.05) in earthen ponds which treated with poultry manure. The result showed that despite iso-nutrients content, the nutrient status of poultry manure proved to be superior to cow manure.

A preliminary observation on water quality and plankton of an earthen fish pond in Bangladesh: recommendations for future studies.

The present study provides a characterization of water quality and plankton samples in earthen fish pond in Rajshahi, Bangladesh. Sampling was done over a period of six months, running from October, 2004 through March, 2005. All the water quality parameters were within the optimal ranges for plankton productivity. Temperatures varied from 19.75 to 27.25 degrees C; transparency, 24.75-29.50 cm; pH, 6.62-7.85; Dissolved Oxygen (DO), 3.87-5.85 mg L(-1); free CO2 5.25-7.25 mg L(-1) and bicarbonate (HCO3) alkalinity, 81.25-147.5 mg L(-1). Analyses of plankton samples recorded a total of 5 classes phytoplankton viz.; Bacillariophyceae, Chlorophyceae, Cyanophyceae, Dinophyceae, Euglenophyceae and 2 classes of zooplankton; Crustacea and Rotifera. The phytoplankton population was comprised of 17 genera belonging to Cyanophyceae (5 classes, 34.47%), Bacillariophyceae (3, 13.87%), Cyanophyceae (3, 34.48%), Euglenophyceae (3, 10.68%) and 1 to Dinophyceae (6.50%). The zooplankton population consisted of 10 genera belonging to Rotifera (4, 40.13%) and Crustacea (6, 59.87%). Phytoplankton and zooplankton abundance varied from 60800 to 239400 units/l and 7620 to 12160 units/l, respectively. It is concluded that the phytoplankton groups provide the main support for earthen pond aquaculture in the pond compared to zooplankton classes. The information provides for more research to compare water quality and pond plankton characteristics in earthen aquaculture systems with and without fish stocking. Further studies on the seasonal changes of water quality parameters and its effects on plankton production in the fish ponds and all year extended monitoring is recommended in future studies.