Correction: Occurrence and spatial distribution of heavy metals in landfill leachates and impacted freshwater ecosystem: An environmental and human health threat.

[This corrects the article DOI: 10.1371/journal.pone.0263279.].

Consideration of Climate Change on Environmental Impact Assessment in Tanzania: Challenges and Prospects.

The potential of the environmental impact assessment (EIA) process to respond to climate change impacts of development projects can only be realized with the support of policies, regulations, and actors' engagement. While considering climate change in EIA has become partly mandatory through the EU revised Directive in Europe, African countries are still lagging. This paper assesses Tanzanian policies, laws, regulations, and EIA reports to uncover consideration of climate change impacts, adaptation, and mitigation measures, drawing from the transformational role of EIA. The methodology integrates content analysis, interpretive policy analysis, and discourse analysis. The analyses draw from environmental policy, three regulatory documents and three EIA reports in Tanzania using a multi-cases study design. The aim was to understand how considering Climate Change issues in EIA has played out in practice. Results reveal less consideration of climate change issues in EIA. The policy, laws, and regulations do not guide when and how the EIA process should consider climate change-related impacts mitigation and adaptation. The practice of EIA in the country is utterly procedural in line with regulations provisions. Consequently, environmental impact statements only profile the climatology of the study area without conducting a deeper analysis of the historical and future climate to enhance the resilience of proposed projects. The weakness exposed in the laws and regulations contributes to the challenges of responding to the impacts of climate change through the EIA process. It is possible to address climate change issues throughout the project life cycle, including design, approval, implementation, monitoring, and auditing, provided the policy and regulations guide how and when the EIA process should consider climate change issues. Additionally, increasing stakeholders' awareness and participation can enhance the EIA process's potential to respond to the impacts of climate change.

Antimicrobial and in silico studies of the triterpenoids of Dichapetalum albidum.

Here we report a new polyhydroxylated triterpene, 2ß,6ß,21α-trihydroxyfriedelan-3-one (4) isolated from the root and stem bark of Dichapetalum albidum A. Chev (Dichapetalaceae), along with six known triterpenoids (1-3, 5, 6, 8), sitosterol-3ß-O-D-glucopyranoside (9), a dipeptide (7), and a tyramine derivative of coumaric acid (10). Friedelan-3-one (2) showed an antimicrobial activity (IC50) of 11.40 µg/mL against Bacillus cereus, while friedelan-3α-ol (1) gave an IC50 of 13.07 µg/mL against Staphylococcus aureus with ampicillin reference standard of 19.52 µg/mL and 0.30 µg/mL respectively. 3ß-Acetyl tormentic acid (5) showed an IC50 of 12.50 µg/mL against Trypanosoma brucei brucei and sitosterol-3ß-O-d-glucopyranoside (9) showed an IC50 of 5.06 µg/mL against Leishmania donovani with respective reference standards of IC50 5.02 µg/mL for suramin and IC50 0.27 µg/mL for amphotericin B. Molecular docking of the isolated compounds on the enzyme glucose-6-phosphate dehydrogenase (G6PDH) suggested 3ß-acetyl tormentic acid (5) and sitosterol-3ß-O-D-glucopyranoside (9) as plausible inhibitors of the enzyme in accordance with the experimental biological results observed.

Electroplating wastewater treatment by in-situ formation of organic anions and inorganic anions intercalated layered double hydroxides.

The electroplating wastewater containing various metal ions was treated by adding sodium dodecyl benzene sulfonate (SDBS) and regulating pH value, and the resulting precipitates were characterized by X-ray diffraction (XRD). The results showed that organic anions intercalated layered double hydroxides (OLDHs) and inorganic anions intercalated layered double hydroxides (ILDHs) were in-situ formed to remove heavy metals during the treatment process. In order to reveal the formation mechanism of the precipitates, SDB- intercalated Ni-Fe OLDHs, NO3- intercalated Ni-Fe ILDHs and Fe3+-DBS complexes were synthsized by co-precipitation at various pH values for comparison. These samples were characterized by XRD, Fourier Transform infrared (FTIR), element analysis as well as the aqueous residual concentrations of Ni2+ and Fe3+ were detected. The results showed that OLDHs with good crystal structures can be formed as pH≤7, while ILDHs began to form at pH = 8. When pH < 7, complexes of Fe3+ and organic anions with the ordered layered structure were formed firstly, and then with increase in pH value, Ni2+ inserted into the solid complex and the OLDHs began to form. However, Ni-Fe ILDHs were not formed when pH ≤ 7. The Ksp (Solubility Product Constant) of OLDHs was calculated to be 3.24 × 10-19 and that of ILDHs was 2.98 × 10-18 at pH = 8, which suggested that OLDHs might be easier to form than ILDHs. The formation process of ILDHs and OLDHs were also simulated through MINTEQ software, and the simulation output verified that OLDHs could be easier to form than ILDHs at pH ≤ 7. Information from this study provides a theoretical basis for effective in-situ formation of OLDHs in wastewater treatment.

Assessment of optical quality of ready-made reading spectacles for presbyopic correction.

PURPOSE: Many presbyopic patients in both developed and developing countries use ready-made reading spectacles for their near vision correction even though the quality of these spectacles cannot always be assured. This study assessed the optical quality of ready-made reading spectacles for presbyopic correction in comparison with relevant international standards. METHODS: A total of 105 ready-made reading spectacles with powers ranging from +1.50 to +3.50 dioptres (D) in +0.50 D steps were randomly procured from open markets in Ghana and assessed for their optical quality, including induced prisms and safety markings. These assessments were done in line with the International Organization for Standardization (ISO 16034:2002 [BS EN 14139:2010]) as well as the standards used in low-resource countries. RESULTS: All lenses (100%) had significant induced horizontal prism that exceeded the tolerance levels stipulated by the ISO standards, while 30% had vertical prism greater than the specified tolerances. The highest prevalence of induced vertical prism was seen in the +2.50 and +3.50 D lenses (48% and 43%, respectively). When compared with less conservative standards, as suggested for use in low-resource countries, the prevalence of induced horizontal and vertical prism reduced to 88% and 14%, respectively. While only 15% of spectacles had a labelled centration distance, none had any safety markings per the ISO standards. CONCLUSION: The high prevalence of ready-made reading spectacles in Ghana that fail to meet optical quality standards indicates the need for more robust, rigorous and standardised protocols for assessing their optical quality before they are sold on the market. This will alleviate unwanted side effects including asthenopia associated with their use. There is also the need to intensify public health awareness on the use of ready-made reading spectacles, especially by patients with significant refractive errors and ocular pathologies.

Environmental implication of geochemical record in the Arctic Ny-Ålesund glacial sediment, Svalbard (Norway).

Glacial sediments as an important end member of the global dust system, could indicate changes in global climate, aerosols sources, ocean elements, and productivity. With global warming, ice caps shrinking and glaciers retreat at high latitudes have attracted concern. To understand the response of glacier to environment and climate in modern high latitude ice-marginal environments, this paper investigated glacial sediments in the Ny-Ålesund region of the Arctic and clarified the response of polar environmental to global changes through geochemical characteristics of glacial sediments. The results showed that: 1) main factors affecting the elements distribution of the Ny-Ålesund glacial sediments were thought as soil formation, bedrock and weathering, and biological activity; 2) variations of SiO2/Al2O3 and SiO2/Al2O3 + Fe2O3, indicating low weathering of the soil. The ratio of Na2O/K2O indicating a weak chemical weathering, was negatively correlated to the CIA. With the average CIA of Ny-Ålesund glacial sediments for main minerals of quartz, feldspar, and muscovite as well as dolomite and calcite 50.13, which implied glacial sediments at the early stage of chemical weathering and depletion of Ca and Na; 3) the separating effect of stones and soils by stone circle formation due to thermal conductivity and frost heave makes sediments in stone circle have lower chemical weathering with only two main minerals, albite and quartz; 4) changes of carbonate content in sediments with glacier front retreating in different period implied that weathering rate of calcite averagely reached an estimate of 0.0792%wt/year in glacier A. The succession of vegetation made biological weathering become an important driving force for carbonate leaching from glacial sediments. These results and data provide scientifically significant archive for future global change studies.

Occurrence and Risk Factors of Brucellosis in Commercial Cattle Farms from Selected Districts of the Eastern Coast Zone, Tanzania.

Brucellosis is a disease of major socio-economic importance worldwide, particularly in low-income countries. This retrospective study aimed to estimate seroprevalence and risk factors associated with brucellosis in commercial cattle farms in the eastern coast zone of Tanzania (ECZT). A total of 1,052 serum samples collected from 20 commercial farms were subjected to rose bengal plate test (RBPT) and indirect enzyme-linked immunosorbent assay (i-ELISA). Descriptive analysis was employed to determine frequencies and proportions. To establish risk factors, a multivariate logistic regression analysis was carried out using a backward elimination procedure, following a univariate analysis, with 0.1 set as a cut-off point for the selection of putative risk factors. Agreement between RBPT and i-ELISA was determined using a Kappa coefficient (κ). The overall animal-level seroprevalence was 25.9% based on i-ELISA. Logistic regression analysis revealed that odds of infection were significantly higher in females (OR = 1.8, 95% CI: 1.2-2.5, p = 0.002) and in young animals than in adults (OR = 3.6, CI: 2.1-6.2, p < 0.001). In addition, odds of infection were higher during the wet season (OR = 3.4, CI: 3.2-5.2, p < 0.001), in cattle reared in rural farms (OR = 4.8, CI: 2.0-11.5, p < 0.001), in cattle reared in areas, not in contact with wildlife (OR = 2.9, CI: 1.4-2.3, p = 0.004), and in medium-sized farms (OR = 12.5, CI: 6.9-22.9, p < 0.001). These findings confirm that bovine brucellosis was prevalent among commercial cattle farms in the ECZT, posing a serious public health concern to the community living in these settings. The one health approach should be adopted for effective control of brucellosis.

Distribution and variation of metals in urban river sediments in response to microplastics presence, catchment characteristics and sediment properties.

Despite well documented studies on metal pollutants in aquatic ecosystems, knowledge on the combined effects of catchment characteristics, sediment properties, and emerging pollutants, such as microplastics (MPs) on the presence of metals in urban river sediments is still limited. In this study, the synergistic influence of MPs type and hazard indices, catchment characteristics and sediment properties on the variability of metals present in sediments was investigated based on a typical urban river, Brisbane River, Australia. It was noted that the mean concentrations of metals in Brisbane River decreases in the order of Al (94,142 ± 12,194 µg/g) > Fe (62,970 ± 8104 µg/g) > Mn (746 ± 258 µg/g) > Zn (196 ± 29 µg/g) > Cu (50 ± 19 µg/g) > Pb (47 ± 25 µg/g) > Ni (25 ± 3 µg/g) while the variability of metals decreases in the order of Pb > Cu > Mn > Al > Ni > Zn > Fe along the river. According to enrichment factor (Ef) contamination categories, Mn, Cu and Zn exert a moderate level of contamination (Ef > 2), while Fe, Ni, and Zn show slight sediment pollution (1 3) was found at sampling locations having a high urbanisation level and traffic related activities. Crustal metal elements (namely, Al, Fe, Mn) were found to be statistically significantly correlated with sediment properties (P < 0.05). Anthropogenic source metals (namely, Cu, Ni, Pb, Zn) were observed to be highly correlated with catchment characteristics. Additionally, the presence of metals in sediments were positively correlated with MPs concentration, and negatively correlated with MPs hazard indices. The outcomes of this study provide new insights for understanding the relationships among metals and various influential factors in the context of urban river sediment pollution, which will benefit the formulation of risk assessment and regulatory measures for protecting urban waterways.

A paper-based optical sensor for the screening of viruses through the cysteine residues of their surface proteins: A proof of concept on the detection of coronavirus infection.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a serious threat to human health. Current methods such as reverse transcription polymerase chain reaction (qRT-PCR) are complex, expensive, and time-consuming. Rapid, and simple screening methods for the detection of SARS-CoV-2 are critically required to fight the current pandemic. In this work we present a proof of concept for, a simple optical sensing method for the screening of SARS-CoV-2 through its spike protein subunit S1. The method utilizes a target-specific extractor chip to bind the protein from the biological specimens. The disulfide bonds of the protein are then reduced into a biothiol with sulfhydryl (SH) groups that react with a blue-colored benzothiazole azo dye-Hg complex (BAN-Hg) and causes the spontaneous change of its blue color to pink which is observable by the naked eye. A linear relationship between the intensity of the pink color and the logarithm of reduced S1 protein concentration was found within the working range 130 ng.mL-1-1.3 pg mL-1. The lowest limit of detection (LOD) of the assay was 130 fg mL-1. A paper based optical sensor was fabricated by loading the BAN-Hg sensor onto filter paper and used to screen the S1 protein in spiked saliva and patients' nasopharyngeal swabs. The results obtained by the paper sensor corroborated with those obtained by qRT-PCR. The new paper-based sensing method can be extended to the screening of many viruses (e.g. the human immunodeficiency virus, the human polyomavirus, the human papilloma virus, the adeno associated viruses, the enteroviruses) through the cysteine residues of their capsid proteins. The new method has strong potential for screening viruses at pathology labs and in remote areas that lacks advanced scientific infrastructure. Further clinical studies are warranted to validate the new sensing method.

Enzymatic N-Allylation of Primary and Secondary Amines Using Renewable Cinnamic Acids Enabled by Bacterial Reductive Aminases.

Allylic amines are a versatile class of synthetic precursors of many valuable nitrogen-containing organic compounds, including pharmaceuticals. Enzymatic allylic amination methods provide a sustainable route to these compounds but are often restricted to allylic primary amines. We report a biocatalytic system for the reductive N-allylation of primary and secondary amines, using biomass-derivable cinnamic acids. The two-step one-pot system comprises an initial carboxylate reduction step catalyzed by a carboxylic acid reductase to generate the corresponding α,ß-unsaturated aldehyde in situ. This is followed by reductive amination of the aldehyde catalyzed by a bacterial reductive aminase pIR23 or BacRedAm to yield the corresponding allylic amine. We exploited pIR23, a prototype bacterial reductive aminase, self-sufficient in catalyzing formal reductive amination of α,ß-unsaturated aldehydes with various amines, generating a broad range of secondary and tertiary amines accessed in up to 94% conversion under mild reaction conditions. Analysis of products isolated from preparative reactions demonstrated that only selective hydrogenation of the C=N bond had occurred, preserving the adjacent alkene moiety. This process represents an environmentally benign and sustainable approach for the synthesis of secondary and tertiary allylic amine frameworks, using renewable allylating reagents and avoiding harsh reaction conditions. The selectivity of the system ensures that bis-allylation of the alkylamines and (over)reduction of the alkene moiety are avoided.

The Role of Childhood Trauma in Psychosis and Schizophrenia: A Systematic Review.

Schizophrenia (SCZ) is a prevalent cause of disability worldwide. Distinguished mainly by psychosis, behavioral alterations could range from hallucinations to delusions. This systematic review examines evidence of a relationship between childhood trauma/adverse life events and psychosis, especially in SCZ. A methodical search provided reproducible results using these five databases: PubMed, ScienceDirect, Semantic Scholar, JSTOR, and Cochrane Library. The systematic search focused on articles published between July 2016 and July 2021. The search strategy utilized specific keywords relevant to SCZ, psychosis, and childhood trauma. The formulation of specified inclusion and exclusion criteria was necessary to ensure a comprehensive narrowed-down search, such as the inclusion of free full-text articles published or translated in English and exclusion of irrelevant subject areas. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a strategic search initially identified 741 articles; three additional articles were identified from citation searching. After relevance screening, duplicate removal, and quality appraisal, 12 studies from databases/registers and three from citation searching met the criteria proving relevance to our review with minimal evidence of bias. The final selected 15 studies included observational studies and reviews. A review of relevant data unveiled findings on childhood adversity, individual lived experiences, and their involvement in SCZ. Evidence suggests that certain neurobiological processes occur in brain after trauma. The inflammation and dysregulation from oxidative stress predispose patients to an at-risk-mental state, facilitating the progression to SCZ. This review encourages further evaluation of early trauma detection and the potential benefits of early intervention.

Occurrence and spatial distribution of heavy metals in landfill leachates and impacted freshwater ecosystem: An environmental and human health threat.

Municipal landfill leachates are a source of toxic heavy metals that have been shown to have a detrimental effect on human health and the environment. This study aimed to assess heavy metal contamination in leachates, surface water, and sediments from non-sanitary landfills in Uyo, Nigeria, and to identify potential health and environmental effects of leachate contamination. Over the wet and dry seasons, surface water and sediment samples were collected from an impacted freshwater ecosystem, and leachates samples from six monitoring wells. Elemental analyses of samples were conducted following standard analytical procedures and methods. The results indicated that leachate, surface water, and sediment samples all had elevated levels of heavy metals, implying a significant impact from landfills. Pollution indices such as the potential ecological risk index (PERI), pollution load index (PLI), degree of contamination (Cd), modified degree of contamination (mCd), enrichment factor (EF), geoaccumulation index (Igeo), and Nemerov pollution index (NPI) were used to assess the ecological impacts of landfill leachates. The following values were derived: PERI (29.09), PLI (1.96E-07), Cd (0.13), mCd (0.16), EF (0.97-1.79E-03), Igeo (0), and NPI (0.74). Pollution indicators suggested that the sediment samples were low to moderately polluted by chemical contaminants from the non-sanitary landfills, and may pose negative risks due to bioaccumulation. Human health risks were also assessed using standard risk models. For adults, children, and kids, the incremental lifetime cancer rate (ILCR) values were within the acceptable range of 1.00E-06-1.00E-04. The lifetime carcinogenicity risks associated with oral ingestion exposure to heavy metals were 9.09E-05, 1.21E-05, and 3.60 E-05 for kids, adults, and children, respectively. The mean cumulative risk values for dermal exposures were 3.24E-07, 1.89E-06, and 1.17E-05 for adults, children, and kids, respectively. These findings emphasized the risks of human and biota exposure to contaminants from landfills.

Adsorption-desorption behavior of heavy metals in aquatic environments: Influence of sediment, water and metal ionic properties.

Limited knowledge of the combined effects of water and sediment properties and metal ionic characteristics on the solid-liquid partitioning of heavy metals constrains the effective management of urban waterways. This study investigated the synergistic influence of key water, sediment and ionic properties on the adsorption-desorption behavior of weakly-bound heavy metals. Field study results indicated that clay minerals are unlikely to adsorb heavy metals in the weakly-bound fraction of sediments (e.g., r = -0.37, kaolinite vs. Cd), whilst dissociation of metal-phosphates can increase metal solubility (e.g., r = 0.61, dissolved phosphorus vs. Zn). High salinity favors solubility of weakly-bound metals due to cation exchange (e.g., r = 0.60, conductivity vs. Cr). Dissolved organic matter does not favor metal solubility (e.g., r = -0.002, DOC vs. Pb) due to salt-induced flocculation. Laboratory study revealed that water pH and salinity dictate metal partitioning due to ionic properties of Ca2+ and H+. Selectivity for particulate phase increased in the order Cu>Pb>Ni>Zn, generally following the softness (2.89, 3.58, 2.82, 2.34, respectively) of the metal ions. Desorption followed the order Ni>Zn>Pb>Cu, which was attributed to decreased hydrolysis constant (pK1 = 9.4, 9.6, 7.8, 7.5, respectively). The study outcomes provide fundamental knowledge for understanding the mobility and potential ecotoxicological impacts of heavy metals in aquatic ecosystems.

Influence of land use class and configuration on water-sediment partitioning of heavy metals.

Influence of land use and population characteristics on solid-liquid partitioning of heavy metals in aquatic ecosystems is little understood. This study hypothesised that the partitioning of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) between water and sediments is influenced by different land use classes, their configuration patterns including patch density, Shannon's diversity index, largest patch index, and splitting index and population density. Relationships between variables were investigated from different distances to the stream network (sub-catchment and riparian scales) and considering land use patterns within individual land use classes and individual sub-catchments as a whole (class and landscape levels, respectively). The study outcomes confirmed that the influence of land use and configuration on metals partitioning is scale independent. However, population density increases metal bioavailability at the riparian scale compared to the sub-catchment scale. Agricultural lands discharge the highest fractions of dissolved metals at both spatial scales (eigenvectors = 0.409 - sub-catchment, and -0.533 - riparian, whilst metals have opposite loadings). Positive relationships between splitting index and metal partitioning confirmed that the division of anthropogenic land uses into smaller patches reduces water pollution. However, high fragmentation of forested areas increases the fraction of soluble metals. Further, high patch density and patch diversity are beneficial for controlling the solubility of some metals. Configuration metrics at the landscape level fundamentally reproduce the patterns of the largest land use type and are not effective for assessing metal partitioning. Therefore, analyses at the class level are preferred. This research investigation contributes essential knowledge to improve land use management strategies and, thereby, help safeguard urban waterways.

Discovery of Novel Cyclic Ethers with Synergistic Antiplasmodial Activity in Combination with Valinomycin.

With drug resistance threatening our first line antimalarial treatments, novel chemotherapeutics need to be developed. Ionophores have garnered interest as novel antimalarials due to their theorized ability to target unique systems found in the Plasmodium-infected erythrocyte. In this study, during the bioassay-guided fractionation of the crude extract of Streptomyces strain PR3, a group of cyclodepsipeptides, including valinomycin, and a novel class of cyclic ethers were identified and elucidated. Further study revealed that the ethers were cyclic polypropylene glycol (cPPG) oligomers that had leached into the bacterial culture from an extraction resin. Molecular dynamics analysis suggests that these ethers are able to bind cations such as K+, NH4+ and Na+. Combination studies using the fixed ratio isobologram method revealed that the cPPGs synergistically improved the antiplasmodial activity of valinomycin and reduced its cytotoxicity in vitro. The IC50 of valinomycin against P. falciparum NF54 improved by 4-5-fold when valinomycin was combined with the cPPGs. Precisely, it was improved from 3.75 ± 0.77 ng/mL to 0.90 ± 0.2 ng/mL and 0.75 ± 0.08 ng/mL when dosed in the fixed ratios of 3:2 and 2:3 of valinomycin to cPPGs, respectively. Each fixed ratio combination displayed cytotoxicity (IC50) against the Chinese Hamster Ovary cell line of 57-65 µg/mL, which was lower than that of valinomycin (12.4 µg/mL). These results indicate that combinations with these novel ethers may be useful in repurposing valinomycin into a suitable and effective antimalarial.

Risk of Mucormycosis in Diabetes Mellitus: A Systematic Review.

Hyperglycemia or diabetes mellitus (DM) is a disorder of the endocrine system. In this condition, the body is insulin-deficient or resistant to insulin. Due to insulin deficiency or resistance, the body is unable to process sugar. The worldwide prevalence of diabetes mellitus is rising substantially. Hyperglycemia makes the immune system weak, which increases the risk of infection in a diabetic patient. Fungal infection is more common in DM. Mucormycosis is a rare fungal infection in a healthy individual, but in DM, it can cause severe complications and even be fatal if not treated adequately and timely. In our literature review, a total of 19 published articles from the PubMed database and Google Scholar were included. We combed the PubMed database and Google Scholar by using various inclusion and exclusion criteria. The result of the review study shows the increased risk of mucormycosis in a diabetic patient.

Antibody coated conductive polymer for the electrochemical immunosensing of Human Cardiac Troponin I in blood plasma.

Cardiac troponin I (cTnI) is a sensitive biomarker for cardiovascular disease (CVD). Rapid determination of cTnI concentration in blood can greatly reduce the potential of significant heart damage and heart failure. Herein, we demonstrate a new electrochemical immunosensor for selective affinity binding and rapid detection of cTnI in blood plasma by an electrochemical method. A conductive film of "poly 2,5-bis(2-thienyl)3,4-diamine-terthiophene (PDATT)" was deposited onto an Indium Tin Oxide (ITO) electrode using chronoamperometry. Anti-cardiac troponin I antibody was then attached to the two amine (NH2) groups substituted on the central thiophene of terthiophene repeating unit of the polymer chain via amide bond formation. The gaps on the surface of the antibody coated immunosensor were backfilled with bovine serum albumin (BSA) to prevent nonspecific binding of interfering molecules. Differential pulse voltammetry (DPV) was used to determine cTnI upon the formation of cTnI immunocomplex on the sensing surface, appearing a peak at 0.27 V. The response range was 0.01-100 ng mL-1 with limit of quantification down to 0.01 ng mL-1. The developed immunosensor was used to determine cTnI in spiked blood plasma without interference from cardiac troponin T (cTnT). Therefore, this new sensor can be utilised for the detection of cTnI biomarker in pathological laboratories and points of care in less than 15 min.

Surface-Dependent Intermediate Adsorption Modulation on Iridium-Modified Black Phosphorus Electrocatalysts for Efficient pH-Universal Water Splitting.

2D black phosphorus (BP) is one promising electrocatalyst toward hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) catalysis. The too strong adsorption of oxygen intermediates during OER, while the too weak adsorption of hydrogen intermediate during HER, however, greatly compromise its practical water splitting applications with overpotentials as high as 450 mV for OER and 420 mV for HER to achieve 10 mA cm-2 under alkaline conditions. Herein, by rationally introducing the nanosized iridium (Ir) modifier together with optimized exposing surface toward electrolytes, an efficient Ir-modified BP electrocatalyst with much favorable adsorption energies toward catalytic intermediates possesses an outstanding pH-universal water splitting performance, surpassing the nearly all reported BP-based catalysts and the commercial noble-metal catalysts. The Ir-modified BP catalyst with the optimized exposed surfaces only requires an overall cell voltage of 1.54 and 1.57 V to achieve 10 mA cm-2 in acidic and alkaline electrolysers, respectively. This design uncovers the potential applications of 2D BP in practical electrocatalysis fields via decreasing reaction intermediate adsorption energy barriers and promoting the interfacial electron coupling for heterostructured catalysts, and offers new insights into the surface-dependent activity enhancement mechanism.

Prospects and Challenges of Developing Plant-Derived Snake Antivenin Natural Products: A Focus on West Africa.

Snakebite envenomation (SBE) is an important public health issue that is now receiving renewed attention following its reclassification as a Neglected Tropical Disease (NTD). Most incidences occur in rural areas of resource-limited countries, as such, timely and appropriate medical care for SBE is often inaccessible. The administration of anti-snake venom serum (ASV) is the only effective definitive treatment of SBE, but treatment failure to available ASVs is not uncommon. Emerging evidence highlights the potential of small-molecule compounds as inhibitors against toxins of snake venom. This presents an encouraging prospect to develop an alternative therapeutic option for the treatment SBE, that may be amenable for use at the point of care in resource-constraint settings. In view of the pivotal role of natural products in modern drug discovery programmes, there is considerable interest in ethno-pharmacological mining of medicinal plants and plant-derived medicinal compounds toward developing novel snake venom-neutralising therapeutics. In this review, we compile a collection of medicinal plants used in the treatment of SBE in West Africa and highlight their promise as potential botanical drugs or as sources of novel small-molecule compounds for the treatment of SBE. The challenges that must be surmounted to bring this to fruition including the need for (sub) regional collaboration have been discussed.