Water Chain Research Articles

Curative Potential of Substances with Bioactive Properties to Alleviate Cd Toxicity: A Review.

Rapid urbanization and industrialization have led to alarming cadmium (Cd) pollution. Cd is a toxic heavy metal without any known physiological function in the organism, leading to severe health threat to the population. Cd has a long half-life (10–30 years) and thus it represents serious concern as it to a great extent accumulates in organs or organelles where it often causes irreversible damage. Moreover, Cd contamination might further lead to certain carcinogenic and non-carcinogenic health risks. Therefore, its negative effect on population health has to be minimalized. As Cd is able to enter the body through the air, water, soil, and food chain one possible way to defend and eliminate Cd toxicities is via dietary supplements that aim to eliminate the adverse effects of Cd to the organism. Naturally occurring bioactive compounds in food or medicinal plants with beneficial, mostly antioxidant, anti-inflammatory, anti-aging, or anti-tumorigenesis impact on the organism, have been described to mitigate the negative effect of various contaminants and pollutants, including Cd. This study summarizes the curative effect of recently studied bioactive substances and mineral elements capable to alleviate the negative impact of Cd on various model systems, supposing that not only the Cd-derived health threat can be reduced, but also prevention and control of Cd toxicity and elimination of Cd contamination can be achieved in the future.

Lycopene Ameliorate Atrazine-Induced Oxidative Damage in the B Cell Zone via Targeting the miR-27a-3p/Foxo1 Axis.

Lycopene, a natural bioactive component, has potential to reduce the risk of environmental factors inducing chronic diseases. It is important to explore lycopene's health benefits and its mechanism. The uncontrolled use of atrazine in agriculture causes critical environmental pollution issues worldwide. Exposure to atrazine through water and food chains is a risk to humans. In this study, mice were orally treated with lycopene and/or different concentrations of atrazine for 21 days to explore the influence of atrazine on the spleen and the role of lycopene's protection in atrazine exposure. The work found that atrazine exerted its toxic role in the B cell zone of the spleen by inducing Foxo1 deficiency. Atrazine caused ROS generation and Pink1/Parkin dysfunction via inducing Foxo1 deficiency, which led to apoptosis in the B cell zone. Additionally, the work revealed that lycopene ameliorates atrazine-induced apoptosis in the B cell zone of the spleen via regulating the miR-27a-3p/Foxo1 pathway. The finding also underscored a novel target of lycopene in maintaining homeostasis during B cell maturation.

Interplay between local protein interactions and water bridging of a proton antenna carboxylate cluster

Proteins that bind protons at cell membrane interfaces often expose to the bulk clusters of carboxylate and histidine sidechains that capture protons transiently and, in proton transporters, deliver protons to an internal site. The protonation-coupled dynamics of bulk-exposed carboxylate clusters, also known as proton antennas, is poorly described. An essential open question is how water-mediated bridges between sidechains of the cluster respond to protonation change and facilitate transient proton storage. To address this question, here I studied the protonation-coupled dynamics at the proton-binding antenna of PsbO, a small extrinsinc subunit of the photosystem II complex, with atomistic molecular dynamics simulations and systematic graph-based analyses of dynamic protein and protein-water hydrogen-bond networks. The protonation of specific carboxylate groups is found to impact the dynamics of their local protein-water hydrogen-bond clusters. Regardless of the protonation state considered for PsbO, carboxylate pairs that can sample direct hydrogen bonding, or bridge via short hydrogen-bonded water chains, anchor to nearby basic or polar protein sidechains. As a result, carboxylic sidechains of the hypothesized antenna cluster are part of dynamic hydrogen bond networks that may rearrange rapidly when the protonation changes.

Self-assembly of Polyfluorene Molecular Brushes with Poly(methacrylic acid) Side Chains in Ethanol and Water

Self-assembly of Polyfluorene Molecular Brushes with Poly(methacrylic acid) Side Chains in Ethanol and Water

Proton Configuration in Water Chain on Pt(533).

In this paper, a wetting behavior of Pt(533) is studied by using heterodyne-detected vibrational sum-frequency generation spectroscopy under an ultrahigh-vacuum condition at 145 K. The imaginary parts of the surface nonlinear susceptibility (Imχ(2)) of the H-bonded OH stretching region are successfully obtained for submonolayer water coverage that show negative bands indicating H-down (proton pointing to the substrate) configurations both for the water at the step and at the terrace. The growth manner of the Imχ(2) signal with coverage and the results of an isotopic dilution are consistent with a model in which a one-dimensional (1D) chain at the step forms a "zigzag" structure that contains H-down orientations. This finding resolves the previous controversy in the literature concerning the proton configuration in the 1D water chain at the step.

Strong and Tough Physical Eutectogels Regulated by the Spatiotemporal Expression of Non‐Covalent Interactions

AbstractPhysical eutectogels are appealing materials for technological devices due to their superior ionic conductivity, thermal and electrochemical stability, non‐volatility, and low cost. Nevertheless, current physical eutectogels are suffering from weak mechanical strength and toughness. Here, taking advantage of the distribution difference of polyvinyl alcohol (PVA) in water and deep eutectic solvents (DESs), a simple and universal solvent‐replacement approach is proposed to regulate the spatiotemporal expression of intra/interpolymer interactions to prepare strong and tough physical eutectogels. The exchange of DESs with water can restrengthen the weakened interactions between PVA chains in water, enabling PVA to crystallize to construct a uniform and robust polymer network. Consequently, the resultant PVA eutectogel exhibits record‐high strength (20.2 MPa), toughness (62.7 MJ m–3), and tear‐resistance (tearing energy Σ42.4 kJ m–2), while possessing excellent stretchability (Σ550% strain), repairability, and adhesive performance. Furthermore, this strategy is proven to be universally applicable to various species of polymers, and even can be utilized to fabricate continuous and conductive eutectogel fibers, demonstrating potential as engineering materials and wearable sensors.

Hepatitis E virus in pigs and the environment: An updated review of public health concerns.

Hepatitis E virus (HEV) is an important public health problem and is responsible for both acute and chronic viral hepatitis. Public health implications of HEV are derived from its transmission route, either water-borne or food-borne, and its zoonotic potential. Not only in developing countries, but HEV cases are also found in a high number in developed countries. The spread of HEV to the environment might pollute surface waters, which could act as the source of infection for both humans and animals. Identification of the virus in animal products suggests the circulation of HEV within water and food chains. High seroprevalence and circulation of HEV in livestock, in particular pigs, as well as in environmental samples warrants further investigation into pig markets. HEV virulence in different environments and meat supply chains could shed light on the possible sources of infection in humans and the degree of occupational risk. The purpose of this review is to discuss HEV infections with an emphasis on livestock- and environment-related risk factors, and food-borne, water-borne, and zoonotic transmissions.

A simple molecular simulation strategy for rapid prediction of BTEX sorption on a surface-modified sorbent

Sorption of benzene, toluene, ethylbenzene, o-xylene, m-xylene, and p-xylene (BTEX) molecules on Fe3O4@SiO2@C18 sorbent allows the idea of entering the BTEX between the C18 (octadecyl) chains. This process resembles BTEX+C18 mixing. Given the dominant effect of non-bond interactions, it should be possible to predict the sorption behavior using force field-based molecular simulations. Experimental data, i.e. sorption efficiency of Fe3O4@SiO2@C18 towards BTEX in aqueous environment, were compared with results of two simulation strategies aimed at predicting sorption behavior using models significantly simplified compared to the real Fe3O4@SiO2@C18 structure. The first strategy involved molecular dynamics performed on models containing only the shell with C18 chains in water with BTEX. The second strategy involved miscibility calculations (based on modified Flory-Huggins theory) performed on models containing only pairs of molecules: C18+BTEX and H2O+BTEX. Results of both simulation strategies are in good agreement with experimental data, i.e. BTEX sorption on Fe3O4@SiO2@C18 can be studied using significantly simplified models. Given the speed of miscibility calculations and the simplicity of models used (pairs of molecules), the preparation of much larger models and time-consuming molecular dynamics simulations are not necessary. The sorption efficiency can be easily and quickly predicted by the miscibility calculations.

Water jumps over a nanogap between two disjoint carbon nanotubes assisted by thermal fluctuation

Temperature determines thermal fluctuations of molecules on the nanoscale, and thus should be essential to the nanofluidic transport. Despite of considerable work in the context of nanofluidic transport, most of previous work focus on the carbon nanotubes (CNTs) with intact structures, the broken CNTs are rarely explored. In this work, we investigate the transport of single-file water molecules through two disjoint CNTs with a nanogap by molecular dynamics simulations. At room temperature, with the increase in nanogap length, the water flow exhibits a sudden decrease to zero, suggesting an excellent on–off gate. This is because for large nanogaps, the single-file water chain will be breakdown, which also results in the reduction in water occupancy and hydrogen bond number. The water translocation time, dipole orientation and flipping frequency, as well as density profiles are also found to be dependent on the CNT nanogap. More interestingly, rising the temperature significantly promotes the water jumping over large nanogaps, where the water flow exhibits a monotonous increase. These results are helpful for the design of nanoscale devices with gap structures, particularly nanofluidic gates.

Design, Manufacturing, Characterization and Evaluation of Lipid Nanocapsules to Enhance the Biopharmaceutical Properties of Efavirenz.

Despite their incredible contribution to fighting viral infections, antiviral viral resistance is an increasing concern and often arises due to unfavorable physicochemical and biopharmaceutical properties. To address this kind of issue, lipid nanocapsules (LNC) are developed in this study, using efavirenz (EFV) as a drug model. EFV solubility was assessed in water, Labrafac Lipophile and medium chain triglycerides oil (MCT oil). EFV turned out to be more soluble in the two latter dissolving media (solubility > 250 mg/mL); hence, given its affordability, MCT oil was used for LNC formulation. LNC were prepared using a low-energy method named phase inversion, and following a design of experiments process. This one resulted in polynomial models that predicted LNC particle size, polydispersity index and zeta potential that were, respectively, around 50 nm, below 0.2 and below −33 mV, for the optimized formulations. Once synthesized, we were able to achieve an encapsulation efficacy of 87%. On the other hand, high EFV release from the LNC carrier was obtained in neutral medium as compared to acid milieu (pH 4) with, respectively, 42 and 27% EFV release within 74 h. Other characterization techniques were applied and further supported the successful encapsulation of EFV in LNCs in an amorphous form. Stability studies revealed that the developed LNC were quite stable over the period of 28 days. Ultimately, LNCs have been demonstrated to improve the biopharmaceutical properties of EFV and could therefore be used to fight against antiviral resistance.

Risk assessment of Cryptosporidium intake in drinking water treatment plant by a combination of predictive models and event-tree and fault-tree techniques

Risk-informed decision making permits a more effective water safety management. In this framework, this article introduces the rationale and proposes a new approach to carry out a quantitative risk assessment along the water chain, from river source to tap water, by integrating predictive modelling combined with event-tree and fault-tree techniques. The model developed by this approach could not only account for normal but also for abnormal process conditions in the water treatment plant, as well as assess the real impact of the applied safety controls, such as turbidity control. A sensitivity study was conducted to determine the effect of considering a typical drinking water treatment plant (DWTP), i.e. coagulation, sedimentation and filtration with two turbidity controls (on intake and after filtration) on the risk of infection due to exposure to Cryptosporidium in tap water. The results showed that, with the current effectiveness of turbidity reduction in the DWTP, the first control did not minimise the annual risk of Cryptosporidium infection (3.6E-04) and only limiting turbidity after filtration to below 0.01NTU provided a clear reduction in risk (7.7E-05) at the cost of rejecting 60 % of the water after the control. The lowest risk was found when turbidity reduction was set at 4 logs (8.48E-06), although this means that the effectiveness of turbidity reduction should be greatly improved. It was therefore concluded that supplementing the current treatment with alternative barriers such as UV or ozone disinfection and/or implementing direct control of Cryptosporidium concentration should be considered.

Hybrid Pyridine-Pyridone Foldamer Channels as M2-Like Artificial Proton Channels.

Currently, completely abiotic channel systems that concurrently reproduce the high selectivity and high permeation rate of natural protein channels are rare. Here, we provide one such biomimetic channel system, i.e., a novel family of helically folded hybrid amide foldamers that can serve as powerful artificial proton channels to mimic key transport features of the exceptionally selective Matrix-2 (M2) proton channels. Possessing an angstrom-scale tubular pore 3 Å in diameter, these low water permeability artificial channels transport protons at a rate 1.22 and 11 times as fast as gramicidin A and M2 channels, respectively, with exceptionally high selectivity factors of 167.6, 122.7, and 81.5 over Cl- , Na+ , and K+ ions. Based on the experimental and computational findings, we propose a novel proton transport mechanism where a proton may create a channel-spanning water chain from two or more short water chains to facilitate its own transmembrane flux via the Grotthuss mechanism.

Hybrid Pyridine–Pyridone Foldamer Channels as M2‐Like Artificial Proton Channels

AbstractCurrently, completely abiotic channel systems that concurrently reproduce the high selectivity and high permeation rate of natural protein channels are rare. Here, we provide one such biomimetic channel system, i.e., a novel family of helically folded hybrid amide foldamers that can serve as powerful artificial proton channels to mimic key transport features of the exceptionally selective Matrix‐2 (M2) proton channels. Possessing an angstrom‐scale tubular pore 3 Å in diameter, these low water permeability artificial channels transport protons at a rate 1.22 and 11 times as fast as gramicidin A and M2 channels, respectively, with exceptionally high selectivity factors of 167.6, 122.7, and 81.5 over Cl−, Na+, and K+ ions. Based on the experimental and computational findings, we propose a novel proton transport mechanism where a proton may create a channel‐spanning water chain from two or more short water chains to facilitate its own transmembrane flux via the Grotthuss mechanism.

Microplastics May Be a Significant Cause of Male Infertility.

Due to the problematic degradation properties of plastics, the decomposition of plastic results in the formation of numerous microplastics (MPs), less than 5 mm in diameter. These MPs enter the soil and the ocean, eventually passing through the air, water, or food chain back to the human body and harming human health. In the last 80 years, male semen analysis parameters have shown a significant decline for unknown reasons, speculated to be caused by pollutants. No studies examined the relationship between human MP exposure and male infertility. In this article, we reviewed the relevant animal experimental research literature in recent years and calculated that the minimum human equivalent dose of MPs leading to abnormal male semen quality is 0.016 mg/kg/d. The literature comparison found that MP exposure in Japan and South Korea was close to this value. These results suggest that MPs can affect male semen quality and that MPs may significantly impact male fertility.

Coil-to-Bridge Transitions of Self-Assembled Water Chains Observed in a Nanoscopic Meniscus.

Ten downward portions in the large oscillatory force–distance curve reported earlier are analyzed to understand a nanoscale water meniscus confined between a sharp probe and a flat substrate in air. The sigmoidal shape of each portion leads to the assumption that the meniscus is made up of n independent transitions of two states: one for a coil state and the other for a bridge state. The analysis reveals that each downward portion occurs due to a coil-to-bridge transition of n self-assembled water chains whose length ranges between 197 and 383 chain units. The transition provides novel insights into water’s unique properties like high surface tension and the long-range condensation distances.

Relative Gut Length and Gastro-somatic Index of Acanthopagrus arabicus (Iwatsuki, 2013) from the Offshore Waters of Pakistan

Relative gut length, Zihler’s index, and Gastro-somatic index of Acanthopagrus arabicus were studied to investigate its feeding intensity and feeding habit, by collecting 240 samples of fishes from two fishing harbors of Pakistan from September 2017 to August 2018. According to the results, fish mean total length ranged from 16.26 ± 2.83 cm (in June) to 30.89 ± 5.16 cm (in September), and mean total weight ranged from 77.70 ± 42.25 g (in June) to 486.80 ± 237.28 g (in November). The total length and gut length of A. arabicus have a strong statistical relationship (P < 0.05). In A. arabicus, the overall relative gut length (RGL) values were ranged from 0.69 to 2.63 with a mean value of 1.57 ± 0.31. The RGL lowest (1.35) and highest (1.70) value was analyzed in the size groups ranging 12.0 - 16.0 cm TL and 24.1 - 28.0 cm TL respectively. However this value is not much greater than 1, A. arabicus could be described as an omnivorous feeding habit in coastal waters of Pakistan. The temporal changes in the feeding intensity of A. arabicus were found as the Gastro-somatic index (Ga-SI) presented a significant difference during the twelve months (ANOVA, P < 0.05). The Gastro-somatic index lowest value was found in January (1.55 ± 0.59) and highest in August (5.66 ± 3.26). This type of study is beneficial for aquaculture as well as assessing the ecological role of A. arabicus along with its position in the food chain of Pakistani coastal waters.

Health risk associated with the collection, transport, and storage practices of drinking water by the population of the Dschang city, West‐Cameroon

AbstractPersistence of water‐borne diseases in Dschang raises the question of drinking water management. The aim of this work was to establish a link between drinking water chain and its quality. Eighty‐four water samples were followed and analyzed (membrane filter technique), from collection points, after transport, and then after 1 and 2 days of storage. A progressive degradation of water quality was observed regardless of the standing of the district and the type of container used. Salmonella species absent at the collection point were subsequently detected. After 2 days of storage, the highest rates were obtained in water collected with buckets in the water collection points of Madagascar, Gendarmerie, and Campus C Districts. The fecal coliform rate increased respectively in CFU/100 ml from 10 to 5100, 20 to 2333, and 10 to 953 and that of fecal streptococcus from 0 to 383, 6 to 380, and 4 to 125. The poor condition of the containers is indexed. This variation is partly responsible for the persistence of water‐borne diseases in the town of Dschang.

Thallium isotopic compositions as tracers in environmental studies: A review.

Thallium is a highly poisonous heavy metal. Since Tl pollution control has been neglected worldwide until the present, countless Tl pollutants have been discharged into the environment, endangering the safety of drinking water, farmland soil, and food chain, and eventually posing a great threat to human health. However, the source, occurrence, pathway and fate of Tl in the environment remains understudied. As Tl in non-contaminated systems and from anthropogenic origin exhibits generally different isotopic signatures, which can provide fingerprint information and a novel way for tracing the anthropogenic Tl sources and understanding the environmental processes. This review summarizes: (i) the state-of-the-art development in highly-precise determination analytical method of Tl isotopic compositions, (ii) Tl isotopic fractionation induced by the low-temperature surface biogeochemical process, (iii) Tl isotopic signature of pollutants derived from anthropogenic activities and isotopic fractionation mechanism of Tl related to the high-temperature industrial activities, and (iv) application of Tl isotopic composition as a new tracer emerging tracer for source apportionment of Tl pollution. Finally, the limitations and possible future research about Tl isotopic application in environmental contamination is also proposed: (1) Tl fractionation mechanism in different environmental geochemistry processes and industrial activities should be further probed comprehensively; (2) Tl isotopes for source apportionment should be further applied in other different high Tl-contaminated scenarios (e.g., agricultural systems, water/sediment, and atmosphere).

Near Infrared Spectroscopy As an Effective Way of Studying Hydrogen Bonding in a LiCl–H2O–CO2 Ternary Mixture

Abstract The possibility of using near IR spectroscopy to analyze the effect isobaric heating has on hydrogen bonding in an aqueous solution of LiCl in equilibrium with supercritical carbon dioxide (a LiCl–H2O–scCO2 ternary mixture) is demonstrated in a wide range of electrolyte concentrations. It is shown that this approach is highly efficient when studying ion and molecular systems with different types of interparticle interactions. The use of near IR spectroscopy allows distinguishing spectral contributions from hydrogen bonded n-mers of bulk water and water molecules in the solvation shells of ions or in ion–water chains like those formed in solutions with extremely high electrolyte concentrations that do not contain bulk water. It is shown for the studied ternary mixture that raising the concentration of electrolyte completely neutralizes the destructive effect of carbon dioxide on the formation of a hydrogen bonded structure of water. The latter is stabilized under the influence of an ion field, which also substantially weakens the temperature effect.

Supramolecular Assemblies and Reversible De‐/ Rehydration in One‐Dimensional Dimethyltin Carboxylates

AbstractThe study presents the synthesis and structural aspects of a new family of dimethyltin carboxylates, [(Me2Sn)2(btec)(bipy)(H2O)] ⋅ 4H2O (1), [Me2Sn(btec)0.5(bipy)]2 ⋅ H2O (2), [Me2Sn(btec)0.5(bipy)] ⋅ 3H2O ⋅ 0.5bipy (3) and [Me2Sn(btec)0.5(phen)] (4) derived from 1,2,4,5‐benzenetetracarboxylic acid (H4btec). The structure in each case adopts a one‐dimensional motif featuring ditin macrocycles with 2,2'‐bipyridine (bipy) or 1,10‐phenanthroline (phen) acting as the chelating ligand. For 1, the lattice water molecules in association with the framework form infinite T4(0)A(1) water chains. The organic hydrate, bipy ⋅ 6H2O in 3 adopts a layered structure comprising T4(2)6(2) water tapes and trans‐bipy. Dehydration of 2 to 2 a results in crystal structure transformation from centrosymmetric P21/c (in 2) to chiral P212121 space group and reveals conformational changes in the ditin macrocycles from chair to boat form. The reversibility of this transformation has been supported by TGA, PXRD, and single‐crystal X‐ray studies.