Charge Separated One-Dimensional Hybrid Cobalt/Nickel Phosphonate Frameworks: A Facile Approach to Design Bifunctional Electrocatalyst for Oxygen Evolution and Hydrogen Evolution Reactions.

Two new organoamine templated one-dimensional transition metal phosphonate compounds are synthesized, and their bifunctional electrocatalytic activities are examined in highly alkaline and acidic media. Compared with state-of-the-art materials, the cobalt phosphonate system is a new fabrication of sustainable and highly efficient catalysts toward electrochemical water splitting systems.

Analysis of moisture, oil, and fatty acid composition of olives by near-infrared spectroscopy: development and validation calibration models.

BACKGROUND: Olive is a new, expanding crop in Georgia. Its oil content steadily increases with maturity, but eventually plateaus at the maximum when the olives should be promptly harvested, avoiding overripening and quality degradation. This requires frequent testing. However, olive quality analysis by wet chemistry is laborious, slow and costly, whereas near-infrared reflectance spectroscopy (NIRS), being precise, accurate, rapid and cheap, could be suitable. We developed and validated NIRS calibration models for moisture, fresh-matter-oil (oil-FMO), dry-matter-oil (oil-DMO) and major fatty acid composition analyses. RESULTS: Of the12 models developed, seven constituents - moisture, oil-FMO, oil-DMO, and palmitic, palmitoleic, oleic and linoleic acids (representing 88-97% of the total fatty acids) had low standard errors and high coefficients of determination (R2 = 0.81-0.98; 1 - VR = 0.74-0.86) for both calibration and cross-validation. For these seven constituents, predictions of an independent validation set yielded excellent agreement between the NIRS predicted values and the reference values with low standard error of prediction (SEP), low bias, high coefficient of determination (r2 = 0.80-0.93) and high ratios of performance to deviation (RPD = SD/SEP; 2.21-3.85). CONCLUSION: Precise, accurate and rapid analysis of fresh olives for moisture, oil and major fatty acid composition can be done at a low cost using NIRS, meeting the analytical needs of the industry. © 2017 Society of Chemical Industry.

Near-infrared spectroscopic models for analysis of winter pea (Pisum sativum L.) quality constituents.

BACKGROUND: Winter pea (Pisum sativum L.) grows well in a wide geographic region, both as a forage and cover crop. Understanding the quality constituents of this crop is important for both end uses; however, analysis of quality constituents by conventional wet chemistry methods is laborious, slow and costly. Near infrared reflectance spectroscopy (NIRS) is a precise, accurate, rapid and cheap alternative to using wet chemistry for estimating quality constituents. We developed and validated NIRS calibration models for constituent analysis of this crop. RESULTS: Of the 11 constituent models developed, nine constituents including moisture, dry-matter, total-nitrogen, crude protein, acid detergent fiber, neutral detergent fiber, AD-lignin, cellulose and non-fibrous carbohydrate had low standard errors and a high coefficient of determination (R2 = 0.88-0.98; 1 - VR, which is the coefficient of determination during cross-validation = 0.77-0.92) for both calibration and cross-validation, indicating their potential for quantitative predictability. The calibration models for ash (R2 = 0.65; 1 - VR = 0.46) and hemicellulose (R2 = 0.75; 1 - VR = 0.50) also appeared to be adequate for qualitative screening. Predictions of an independent validation set yielded reliable agreement between the NIRS predicted values and the reference values with low standard error of prediction (SEP), low bias, high coefficient of determination (r2 = 0.82-0.95), high ratios of performance to deviation (RPD = SD/SEP; 2.30-3.85) and high ratios of performance to interquartile distance (RPIQ = IQ/SEP; 2.57-7.59) for all 11 constituents. CONCLUSION: Precise, accurate and rapid analysis of winter pea for major forage and cover crop quality constituents can be performed at a low cost using the NIRS calibration models developed. © 2018 Society of Chemical Industry.

Impact and variability of social determinants of health on the transmission and outcomes of COVID-19 across the world: a systematic review protocol.

INTRODUCTION: The COVID-19 pandemic has exacerbated health inequalities across the globe, disproportionately affecting those with poor social determinants of health (SDOHs). It is imperative to understand how SDOH influences the transmission and outcomes (positive case, hospitalisation and mortality) of COVID-19. This systematic review will investigate the impact of a wide range of SDOHs across the globe on the transmission and outcomes of COVID-19. METHODS AND ANALYSIS: This review will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol guidelines. We will search three electronic bibliographical databases (MEDLINE via PubMed, Embase and Scopus), as well as the WHO COVID-19 Global Research on Coronavirus Disease database. We will consider observational studies that report statistical relationships between the SDOHs (as listed in PROGRESS-Plus and Healthy People 2020) and COVID-19 transmission and outcomes. There will be no limitation on the geographical location of publications. The quality of included observational studies will be assessed using a modified version of the Newcastle-Ottawa Scale. A narrative synthesis without meta-analysis reporting standards will be used to report the review findings. ETHICS AND DISSEMINATION: This review will be based on published studies obtained from publicly available sources, and therefore, ethical approval is not required. We will publish the results of this review in a peer-reviewed journal, as well as present the study findings at a national conference. PROSPERO REGISTRATION NUMBER: CRD42021228818.

Identification of a Cd accumulator Conyza canadensis.

One of key steps of phytoremediating heavy metal contaminated soils is still the identification of hyperaccumulator and accumulator. In a former published article, Conyza canadensis L. Cronq. expressed some basic properties of Cd-hyperaccumulators. In this study, concentration gradient experiment and two sample-analyzing experiments were used to identify whether this plant is a Cd-hyperaccumulator. When grown on soil spiked with Cd at the rate of 10 and 25 mg kg(-1) in concentration gradient experiment, C. canadensis had both Cd enrichment factor (EF) and Cd translocation factor (TF) greater than 1, while the shoot biomass did not differ significantly as compared to the control. On the other hand, with Cd-spiking rates of 10 and 25 mg kg(-1), the Cd concentration in the shoot did not exceed 100 mg kg(-1), which is considered as the minimum shoot Cd concentration to qualify as a hyperaccumulator. In the sample-analysis experiments from a Pb-Zn mine area and wastewater irrigation region, C. canadensis also showed Cd-accumulator characteristics. Based on the results accomplished, we propose C. canadensis as a Cd-accumulator.

Effectiveness and potential risk of CaO application in Cd-contaminated paddy soil.

In this study, the accurate effectiveness of CaO in mitigating Cd bioavailability in paddy soil-rice system was investigated and moreover, the potential for reversibility of CaO liming process was provided. Increasing soil pH to ≥6.5 by CaO was determined to be the minimal threshold for minimizing Cd transfer into rice in historically contaminated soils across light to severe Cd levels, while an elevated CaO ratio was needed for soil with recent input of Cd. In CaO remediation treatment, a reduced pool of bioavailable Cd in rhizosphere soil coupled with an increased Cd retention by Fe plaque and an inhibited planta Cd transfer was determined consistently and proposed to be largely responsible for the significant reduction in brown rice Cd. Under continuous simulated acid precipitation test, a negligible level of Cd in eluate with ∼1 unit higher pH than control was recorded with CaO. Significant acidification, however, increased Cd solubilization in the limed soil than in unlimited control, notably at pH 5.5-6.5. As indicated by Visual MINTEQ, a higher Cd-carbonate solubility and much decreased Cd complexation on Fe-(hydr)-oxides across this pH range occurred as a result of elevated Ca input. This suggests that a high soil pH (≥6.5) needs to be permanently maintained once liming has been performed to minimize Cd mobilization. Therefore, amending Cd-contaminated soils with CaO is a cost-effective remedial measure for reducing Cd bioavailability to paddy rice, while a high soil pH need to be permanently maintained to sustain this beneficial effect.

The effect of bullet removal and vegetation on mobility of Pb in shooting range soils.

Lead (Pb) contamination at shooting ranges is a public health concern because Pb is a toxic metal. An experiment was conducted to determine the effect of two best management practices; bullet removal and vegetation, on bioavailability and leachability of Pb in three shooting range (SR) soils. St. Augustine grass was grown in sieved (2 mm) and un-sieved SR soils for 8 weeks after which leachates, soil and plant samples were analyzed. Bullet removal reduced total soil Pb, increased Mehlich-3 Pb in unvegetated soils and increased dissolved organic carbon (DOC) in all soils. Bullet removal increased leaching in two SR soils while grasses reduced leaching but increased water soluble Pb in two SR soils. The roots of the grasses were able to accumulate more Pb in the root (1893-5021 mg kg(-1)) than the aboveground biomass (252-880 mg kg(-1)) due to mobilization of Pb in the rhizosphere. Grasses had a higher plant biomass in unsieved soils suggesting tolerance to the presence of bullets in the unsieved soils. Results suggest that bullet removal probably increased microbial activity and Pb bioavailability in the soil. The leaching and bioavailability of Pb in shooting range soils depends on biological activities and chemical processes in the soil.

Potent, selective and low-calcemic inhibitors of CYP24 hydroxylase: 24-sulfoximine analogues of the hormone 1alpha,25-dihydroxyvitamin D(3).

A dozen 24-sulfoximine analogues of the hormone 1alpha,25-dihydroxyvitamin D(3) were prepared, differing not only at the stereogenic sulfoximine stereocenter but also at the A-ring. Although these sulfoximines were not active transcriptionally and were only very weakly antiproliferative, some of them are powerful hydroxylase enzyme inhibitors. Specifically, 24-(S)-NH phenyl sulfoximine 3a is an extremely potent CYP24 inhibitor (IC(50) = 7.4 nM) having low calcemic activity. In addition, this compound shows high selectivity toward the CYP24 enzyme in comparison to CYP27A1 (IC(50) > 1000 nM) and CYP27B (IC(50) = 554 nM).

Potent, low-calcemic, selective inhibitors of CYP24 hydroxylase: 24-sulfone analogs of the hormone 1alpha,25-dihydroxyvitamin D3.

The new 24-phenylsulfone 4a, a low-calcemic analog of the natural hormone 1alpha,25-dihydroxyvitamin D(3), is a potent (IC(50) = 28nM) and highly selective inhibitor of the human 24-hydroxylase enzyme CYP24.

Low-calcemic, efficacious, 1alpha,25-dihydroxyvitamin D3 analog QW-1624F2-2: calcemic dose-response determination, preclinical genotoxicity testing, and revision of A-ring stereochemistry.

Based on an X-ray crystal structure determination, the A-ring stereochemistry of hybrid analog QW-1624F2-2 (1alpha-hydroxymethyl-16-ene-24,24-difluoro-25-hydroxy-26,27-bis-homovitamin D3) is revised to be 1alpha-CH2OH-3beta-OH. This analog is shown to be approximately 80-100 times less calciuric than the natural hormone 1alpha,25-dihydoxyvitamin D3. This analog is shown also to be non-genotoxic in three different standard assays.

Phytoremediation of arsenic-contaminated groundwater using arsenic hyperaccumulator Pteris vittata L.: effects of frond harvesting regimes and arsenic levels in refill water.

A large-scale hydroponic system to phytoremediate arsenic-contaminated groundwater using Pteris vittata (Chinese brake fern) was successfully tested in a field. In this 30-wk study, three frond-harvesting regimes (all, mature, and senescing fronds) and two water-refilling schemes to compensate for evapotranspiration (high-As water of 140-180 µg/L and low-As water of <7 µg/L) were investigated. Two experiments (Cycle 1 and Cycle 2) were conducted using the same plants in 24 tanks with each containing 600 L of arsenic-contaminated groundwater and 32 ferns. During Cycle 1 and with initial As of 140 µg/L, As in tanks refilled with low-As water was reduced to <10 µg/L in 8 wks compared to <10 µg/L in 17 wks in tanks refilled with high-As water. During Cycle 2 and with initial As of 180 µg/L, the remediation time was reduced by 2-5 wks, indicating that more established ferns were more efficient. In areas where clean water is limiting, refilling high-As water coupled with harvesting senescing fronds is recommended for more effective As phytoremediation.

Effectiveness of best management practices in reducing Pb-bullet weathering in a shooting range in Florida.

This field study evaluated the effectiveness of three best management practices (BMPs) in reducing the weathering of Pb-bullets in a shooting range. The BMPs included replacing soil berm with sand berm, liming sand berm, and removing Pb-bullets from soil berm. Berm samples were collected before and after implementing BMPs and analyzed for total Pb and/or water-soluble Pb. After 11 months of operation, the total Pb concentrations in the sand berm (57 mg kg(-1)) were significantly lower than that in the soil berm (277 mg kg(-1)). The reduced weathering of Pb-bullets in the sand berm was attributed to its lower moisture content and organic matter as both water and CO(2) are critical in chemical weathering. Though liming reduced total Pb concentrations in the sand berm from 497-777 to 302-362 mg kg(-1) after 15 months of application, it increased water-soluble Pb in some cases. While removal of Pb-bullets removed the sources of Pb, X-ray diffraction analysis indicated that its abrasive action transferred metallic Pb to the soil fraction (<2 mm), with total Pb in soil berm increasing from 4,694 to 11,479 mg kg(-1). While all BMPs can be applied to mange Pb in shooting ranges, cautions need to be excised to minimize the adverse impacts.

Arsenic transformation in the growth media and biomass of hyperaccumulator Pteris vittata L.

This study determined the role of plant and microbes in arsenite (AsIII) oxidation in the growth media and the location of AsIII oxidation and arsenate (AsV) reduction in Pteris vittata tissues. P. vittata grew in 0.10-0.27mM AsV or AsIII solution under aerated or sterile condition for 1h to 14d. Arsenic speciation was conducted in the growth media, biomass (roots, rhizomes, rachis, pinnae, and fronds), and sap (rhizomes and fronds). Arsenite was rapidly oxidized in the growth media by microbes (18-67% AsV after 1d) and was then further oxidized in the roots of P. vittata (35% AsV in the roots growing in AsIII media). While limited reduction occurred in the roots (7-8% as AsIII), AsV reduction mostly occurred in the rhizomes (68-71% as AsIII) and pinnae (>90% as AsIII) of P. vittata. Regardless AsIII or AsV was supplied, AsV dominated in the roots while AsIII dominated in the rhizomes and fronds. AsIII translocation from the roots to the fronds was more rapid than AsV. This study shed new insights into arsenic transformation in the growth media and P. vittata biomass and raise new question into the tissue distribution of arsenic reducing and oxidizing enzymes in P. vittata.

Sulfate and glutathione enhanced arsenic accumulation by arsenic hyperaccumulator Pteris vittata L.

This experiment examined the effects of sulfate (S) and reduced glutathione (GSH) on arsenic uptake by arsenic hyperaccumulator Pteris vittata after exposing to arsenate (0, 15 or 30 mg As L(-1)) with sulfate (6.4, 12.8 or 25.6 mg S L(-1)) or GSH (0, 0.4 or 0.8 mM) for 2-wk. Total arsenic, S and GSH concentrations in plant biomass and arsenic speciation in the growth media and plant biomass were determined. While both S (18-85%) and GSH (77-89%) significantly increased arsenic uptake in P. vittata, GSH also increased arsenic translocation by 61-85% at 0.4 mM (p < 0.05). Sulfate and GSH did not impact plant biomass or arsenic speciation in the media and biomass. The S-induced arsenic accumulation by P. vittata was partially attributed to increased plant GSH (21-31%), an important non-enzymatic antioxidant countering oxidative stress. This experiment demonstrated that S and GSH can effectively enhance arsenic uptake and translocation by P. vittata.

Colloid-facilitated Pb transport in two shooting-range soils in Florida.

Shooting range soils with elevated Pb contents are of environmental concern due to their adverse impacts on human and animals. In Florida, the problem merits special attention because of Florida's sandy soil, high rainfall, and shallow groundwater level, which tend to favor Pb migration. This study used large intact soil column to examine colloid-facilitated Pb transport in two Florida shooting-range soils with different physicochemical properties (e.g., organic carbon content, pH, and clay content). Simulated rainwater (SRW) was pumped through the intact soil columns under different ionic strengths (0.07 and 5 mmol L(-1)) and flow rates (2.67, 5.30 and 10.6 cm h(-1)) to mobilize Pb and soil colloids. Our results showed that colloids dominated Pb transport in both soils and there was a significant correlation between colloids and Pb in the leachates. Decreases in ionic strength and increases in flow rate enhanced the release of both colloids and Pb in the soils. Size fraction analyses showed that in OCR soils (sandy soils with low organic carbon), most of the Pb (87%) was associated with coarse colloid fraction (0.45-8 microm). However, high Pb level (66%) was found in the dissolved and nano-sized colloid fraction (<0.1 microm) in the MPR soils (sandy soils with high organic carbon). This suggests that soil properties are important to Pb migration in soils and groundwater. Our study indicated that colloids play an important role in facilitating Pb transport in shooting range soils.

Phytofiltration of arsenic-contaminated groundwater using Pteris vittata L.: effect of plant density and nitrogen and phosphorus levels.

This field-scale hydroponic experiment investigated the effects of plant density and nutrient levels on arsenic (As) removal by the As-hyperaccumulator Pteris vittata L. (Chinese brake fern). All ferns were grown in plastic tanks containing 30 L of As-contaminated groundwater (130 microg x L(-1) As) collected from South Florida. The treatments consisted of four plant densities (zero, one, two, or four plants per 30 L), two nitrogen (N) concentrations (50% or 100% of 0.25-strength Hoagland solution [HS]), and two phosphorous (P) concentrations (15% and 30% of 0.25 strength HS). While low P was more effective than high P for plant As removal initially, N levels showed little effect. At 15% P, it took 3 wk for the ferns at a plant density of four to reduce As to less than 10 microg L(-1) (USEPA and WHO standard), whereas it took 4-6 wk at plant densities of one or two. For reused ferns, established plants with more extensive roots than "first-time" ferns, a low plant density of one plant/30 L was more effective, reducing As in water to less than 10 microg L(-1) in 8 h. This translates to an As removal rate of 400 microg h(-l) plant(-1), which is the highest rate reported to date. Arsenic-concentration in tanks with no plants as a control remained high throughout the experiment. Using more established ferns supplemented with dilute nutrients (0.25 HS with 25% N and 15% P) with optimized plant density (one plant per 30 L) reduced interplant competition and secondary contamination from nutrients, and can be recommended for phytofiltration of As-contaminated groundwater. This study demonstrated that P. vittata is effective in remediating As-contaminated groundwater to meet recommended standards.