Photochemical oxidation of Cr(III) to Cr(VI) in the presence of Fe(III): Influence of Fe(III) concentration and UV wavelength.

The reduction of Cr(VI) to Cr(III) is key to lowering environmental toxicity and mobility, but the reverse process remains less understood. We investigated Cr(III) oxidation mechanisms across various pH levels and light wavelengths (185, 254, and 358 nm) in the presence of Fe(III). At pH 3.

Sulfur-functionalized sawdust biochar for enhanced cadmium adsorption and environmental remediation: A multidisciplinary approach and density functional theory insights.

Pristine biochar typically exhibits limited capacity for heavy metal adsorption due to its inadequate pore development and insufficient surface functionality. This study introduces an innovative chemical strategy to enhance the surface of sawdust biochar with sulfur-based functional groups (C=S, C-S, S-S, S, S-H, -SO, -SO) to significantly improve cadmium (Cd) adsorption. Sulfur-doping using HSO, NaS, and NaSO markedly increased the sulfur content from 0.

Increasing DNA damage sensitivity through corylin-mediated inhibition of homologous recombination.

Background: DNA repair allows the survival of cancer cells. Therefore, the development of DNA repair inhibitors is a critical need for sensitizing cancers to chemoradiation. Sae2 has specific functions in initiating DNA end resection, as well as coordinating cell cycle checkpoints, and it also greatly interacts with the DDR at different levels.

Fabrication of a decellularized liver matrix-based hepatic patch for the repair of CCl4-induced liver injury.

This article primarily introduces a new treatment for liver fibrosis/cirrhosis. We developed a hepatic patch by combining decellularized liver matrix (DLM) with the hepatocyte growth factor (HGF)/heparin-complex and evaluated its restorative efficacy. In vitro prophylactic results, the HGF/heparin-DLM patches effectively mitigated CCl-induced hepatocyte toxicity and restored the cytotoxicity levels to the baseline levels by day 5.

Promotion of phosphate release from humic acid-iron hydroxide coprecipitates in the presence of citric acid.

Phosphate (P) resources are expected to be depleted within a century. Therefore, promoting balanced phosphorus fertilizer use and understanding phosphorus dynamics in soils containing iron (III), organic acids, and iron (III)-organic molecule particulates is crucial. This study investigated the sorption of citric acid onto humic acid-iron hydr(o)xide coprecipitate (HAFHCP) and the reciprocal effects of citric acid and P sorption on HAFHCP with different C/Fe ratios.

Inhibition of continuous cropping obstacle of celery by chemically modified biochar: An efficient approach to decrease bioavailability of phenolic allelochemicals.

The accumulation of allelochemicals released by plants is commonly found in continuous monocropping systems. These chemicals, such as phenolic acids, were shown to be the major sources of autotoxin or pathogen accumulation in soils, leading to a direct or indirect continuous cropping obstacle. In this study, three types of agricultural residuals, i.

Synergism of Fe and Al salts for the coagulation of dissolved organic matter: Structural developments of Fe/Al-organic matter associations.

Dissolved organic matter (DOM) is distributed ubiquitously in water bodies. Ferric ions can flocculate DOM to form stable coprecipitates; however, Al(III) may alter the structures and stability of Fe-DOM coprecipitates. This study aimed to examine the coprecipitation of Fe, Al, and DOM as well as structural developments of Fe-DOM coprecipitates in relation to changes in Fe/Al ratios and pHs.

Organic fragments newly released from heat-treated peat soils create synergies with dissolved organic carbon to enhance Cr(VI) removal.

Surface fires occur naturally or anthropogenically and can raise the temperature at the soil surface up to 600 °C. The heat derived from the surface fire can be subsequently transferred into CO-enriched subsoils. As a result, the chemical compositions of soil organic matter (SOM) may be altered in fire-impacted anaerobic environments, indirectly influencing the redox transformations of pollutants, such as Cr(VI).

Phosphate Removal in Relation to Structural Development of Humic Acid-Iron Coprecipitates.

Precipitation of Fe-hydroxide (FH) critically influences the sequestration of PO and organic matter (OM). While coatings of pre-sorbed OM block FH surfaces and decrease the PO adsorption capacity, little is known about how OM/Fe coprecipitation influences the PO adsorption. We aimed to determine the PO adsorption behaviors on humic acid (HA)-Fe coprecipitates in relation to surface and structural characteristics as affected by HA types and C/(C + Fe) ratios using the Fe and P X-ray absorption spectroscopy.

Tobacco mosaic virus-directed reprogramming of auxin/indole acetic acid protein transcriptional responses enhances virus phloem loading.

Vascular phloem loading has long been recognized as an essential step in the establishment of a systemic virus infection. In this study, an interaction between the replication protein of tobacco mosaic virus (TMV) and phloem-specific auxin/indole acetic acid (Aux/IAA) transcriptional regulators was found to modulate virus phloem loading in an age-dependent manner. Promoter expression studies show that in mature tissues TMV 126/183-kDa-interacting Aux/IAAs predominantly express and accumulate within the nuclei of phloem companion cells (CCs).

Prevalence of Nontyphoidal Salmonella and Salmonella Strains with Conjugative Antimicrobial-Resistant Serovars Contaminating Animal Feed in Texas.

The objective of this study was to characterize 365 nontyphoidal Salmonella enterica isolates from animal feed. Among the 365 isolates, 78 serovars were identified. Twenty-four isolates (7.

A Rapid and Low-Cost PCR Thermal Cycler for Low Resource Settings.

Background: Many modern molecular diagnostic assays targeting nucleic acids are typically confined to developed countries or to the national reference laboratories of developing-world countries. The ability to make technologies for the rapid diagnosis of infectious diseases broadly available in a portable, low-cost format would mark a revolutionary step forward in global health. Many molecular assays are also developed based on polymerase chain reactions (PCR), which require thermal cyclers that are relatively heavy (>20 pounds) and need continuous electrical power.

High performance liquid chromatography-tandem mass spectrometry method for ex vivo metabolic studies of a rhenium-labeled radiopharmaceutical for liver cancer.

The radio-isotope rhenium-labeled N-[2-(triphenylmethyl)thioethyl]-3-aza-19-ethyloxycarbonyl-3-[2-(triphenylmethyl)thioethyl] octadecanoate) ligand (188Re-MN-16ET) is a novel therapeutic agent under preclinical evaluation for hepatoma. A reversed-phase high performance liquid chromatography coupled with a tandem mass spectrometric analysis method and diode array detector (DAD) involving a T type splitter was developed to characterize this pharmaceutical in rat liver tissue solution and determine its biotransformation rate. The separation was accomplished on a C18 column (chromolith silica, 4.

Tombusvirus-based vector systems to permit over-expression of genes or that serve as sensors of antiviral RNA silencing in plants.

A next generation Tomato bushy stunt virus (TBSV) coat protein gene replacement vector system is described that can be applied by either RNA inoculation or through agroinfiltration. A vector expressing GFP rapidly yields high levels of transient gene expression in inoculated leaves of various plant species, as illustrated for Nicotiana benthamiana, cowpea, tomato, pepper, and lettuce. A start-codon mutation to down-regulate the dose of the P19 silencing suppressor reduces GFP accumulation, whereas mutations that result in undetectable levels of P19 trigger rapid silencing of GFP.

A synthetic peptide-acrylate surface for production of insulin-producing cells from human embryonic stem cells.

Human embryonic stem cells (hESCs), due to their self-renewal capacity and pluripotency, have become a potential source of transplantable β-cells for the treatment of diabetes. However, it is imperative that the derived cells fulfill the criteria for clinical treatment. In this study, we replaced common Matrigel with a synthetic peptide-acrylate surface (Synthemax) to expand undifferentiated hESCs and direct their differentiation in a defined and serum-free medium.

Differential requirements for Tombusvirus coat protein and P19 in plants following leaf versus root inoculation.

Traditional virus inoculation of plants involves mechanical rubbing of leaves, whereas in nature viruses like Tomato bushy stunt virus (TBSV) are often infected via the roots. A method was adapted to compare leaf versus root inoculation of Nicotiana benthamiana and tomato with transcripts of wild-type TBSV (wtTBSV), a capsid (Tcp) replacement construct expressing GFP (T-GFP), or mutants not expressing the silencing suppressor P19 (TBSVΔp19). In leaves, T-GFP remained restricted to the cells immediately adjacent to the site of inoculation, unless Tcp was expressed in trans from a Potato virus X vector; while T-GFP inoculation of roots gave green fluorescence in upper tissues in the absence of Tcp.

Host impact on the stability of a plant virus gene vector as measured by a new fluorescent local lesion passaging assay.

Viruses can be used as vectors for transient expression of proteins in plants but frequently foreign gene inserts are not maintained stably over time due to recombination events. In this study the hypothesis was that the choice of plant host affects the foreign gene retention level by a Tomato bushy stunt virus (TBSV) vector expressing green fluorescent protein (GFP). To accomplish this, a novel virus vector integrity bioassay was developed based on an old concept, whereby RNA transcripts of the TBSV-GFP vector were rub-inoculated onto leaves of test plants, and at 3 days post inoculation (dpi), these leaves were used as inoculum for passage to cowpea (Vigna unguiculata), a local lesion host.

Improved foreign gene expression in plants using a virus-encoded suppressor of RNA silencing modified to be developmentally harmless.

Endeavours to obtain elevated and prolonged levels of foreign gene expression in plants are often hampered by the onset of RNA silencing that negatively affects target gene expression. Plant virus-encoded suppressors of RNA silencing are useful tools for counteracting silencing but their wide applicability in transgenic plants is limited because their expression often causes harmful developmental effects. We hypothesized that a previously characterized tombusvirus P19 mutant (P19/R43W), typified by reduced symptomatic effects while maintaining the ability to sequester short-interfering RNAs, could be used to suppress virus-induced RNA silencing without the concomitant developmental effects.

Perfusion-based microfluidic device for three-dimensional dynamic primary human hepatocyte cell culture in the absence of biological or synthetic matrices or coagulants.

We describe a perfusion-based microfluidic device for three-dimensional (3D) dynamic primary human hepatocyte cell culture. The microfluidic device was used to promote and maintain 3D tissue-like cellular morphology and cell-specific functionality of primary human hepatocytes by restoring membrane polarity and hepatocyte transport function in vitro without the addition of biological or synthetic matrices or coagulants. A unique feature of our dynamic cell culture device is the creation of a microenvironment, without the addition of biological or synthetic matrices or coagulants, that promotes the 3D organization of hepatocytes into cord-like structures that exhibit functional membrane polarity as evidenced by the expression of gap junctions and the formation of an extended, functionally active, bile canalicular network.

Comparative analysis of the capacity of tombusvirus P22 and P19 proteins to function as avirulence determinants in Nicotiana species.

We have used an agroinfiltration assay for a comparative study of the roles of tombusvirus P22 and P19 proteins in elicitation of hypersensitive response (HR)-like necrosis and the role of P19 in silencing suppression in Nicotiana species. The advantage of agroinfiltration rather than expression in plant virus vectors is that putative viral avirulence proteins can be evaluated in isolation, eliminating the possibility of synergistic effects with other viral proteins. We found that tombusvirus P22 and P19 proteins elicited HR-like necrosis in certain Nicotiana species but, also, that Nicotiana species could recognize subtle differences in sequence between these proteins.

Diverse and newly recognized effects associated with short interfering RNA binding site modifications on the Tomato bushy stunt virus p19 silencing suppressor.

The Tomato bushy stunt virus-encoded P19 forms dimers that bind duplex short interfering RNAs (siRNAs) to suppress RNA silencing. P19 is also involved in multiple host-specific activities, including the elicitation of symptoms, and in local and/or systemic spread. To study the correlation between those various roles and the siRNA binding by P19, predicted siRNA-interacting sites were modified.

On-chip microdialysis system with flow-through glucose sensing capabilities.

Background: Microdialysis is a sampling technique based on controlling the mass transfer rate of different-sized molecules across a semipermeable membrane. Because the dialysis process has minimal effects on the surrounding fluid, it is viewed as a tool for continuous monitoring of human metabolites. In diabetes treatment, microdialysis probes have been used as sampling systems coupled to a glucose biosensor but may struggle to obtain high recoveries of analytes, as the sampling housing, probes, and glucose sensors are fabricated as separate pieces and then assembled, resulting in a large dead volume, which limits sensing frequency.

On-chip microdialysis system with flow-through sensing components.

Microdialysis probes have been used for diabetes treatment as continuous monitoring system coupled to a glucose sensor. An on-chip microdialysis system with in-line sensing electrodes is demonstrated. As a first step towards greater biosensor integration with this miniaturized microdialysis system, a stacked system with in-line sensing electrodes was developed.

Components of an integrated microfluidic device for continuous glucose monitoring with responsive insulin delivery.

Miniaturized medical diagnostic and treatment devices are currently being developed. Microneedles and miniaturized microdialysis systems are particularly well suited to impact diabetes treatment for continuous glucose monitoring and feedback-controlled insulin delivery. Microneedles are an attractive advanced drug delivery system used to mechanically penetrate the skin and inject insulin intradermally where it is rapidly absorbed by the capillary bed into the bloodstream.