Impact Of Cr Research Articles

Construction of controlled hyper-crosslinked nanofibrous tubes for Cr(VI) removal: Response surface, kinetics, and isotherm

Porous organic polymers (POPs) exhibit significant potential for adsorbing toxic metal ions in wastewater. Developing POPs with controlled morphologies is a pivotal direction in this field. This study synthesized a series of novel hyper-crosslinked nanofibrous tubes designated HCNT-Cn (n = 4, 8, 12, 16) via Friedel-Crafts alkylation and quaternization reactions. These reactions were fine-tuned through a post-synthetic strategy involving varying alkyl chain lengths. These materials were characterized using FT-IR, SEM, N₂ adsorption-desorption isotherms, among others, and they were specifically evaluated for their ability to adsorb Cr(VI). Among the variants, HCNT-C₄ exhibited the highest specific surface area (495.26 m2 g−1), superior hydrophilicity (CA = 48.7°), and optimal adsorption performance. The adsorption kinetics of HCNT-C₄ conformed to a pseudo-second-order model, while its adsorption isotherm aligned with the Langmuir model. An investigation into the impact of Cr(VI) removal was conducted using three independent variables in a Central Composite Design (CCD) response surface model, revealing that under optimal conditions, the Cr(VI) removal efficiency reached 98%. Additionally, a mechanism for Cr(VI) adsorption on HCNT-C₄ was proposed. It was also found that HCNT-C₄ could be reused up to four times, maintaining a removal efficiency of 70%. This study suggests potential applications for removing Cr(VI) from contaminated wastewater.

Assessing the Impact of Hexavalent Chromium (Cr VI) at Varied Concentrations on Spirulina platensis for Growth, Metal Sorption, and Photosynthetic Responses.

Spirulina platensis, a photosynthetic cyanobacterium, has garnered attention for its potential role in environmental remediation due to its ability to absorb and metabolize toxic heavy metals. Understanding its response toward toxicity of one of the most common contaminants, Cr(VI) is crucial for assessing its efficacy in bioremediation efforts. This study aims to investigate the physiological and biochemical responses of Spirulina platensis to varying concentrations of Cr(VI) from 0.5 to 5ppm, shedding light on its potential as a bioindicator for environmental contamination and its suitability for bioremediation purposes. The impact of Cr(VI) on cell density, biosorption, pigment levels, nutrient content, fluorescence response, and photosynthetic efficiency was examined. The study revealed a gradual reduction in cell density, biomass production, and biosorption efficiency with increasing Cr(VI) concentrations. Pigment levels, carbohydrate, protein, and lipid content showed significant decreases, indicating physiological stress. Fluorescence response and photosynthetic efficiency were also adversely affected, suggesting alterations in electron transfer dynamics. A threshold for chromium toxicity was observed at 0.5ppm, beyond which significant physiological disturbances occurred. This investigation highlights the sensitivity of Spirulina platensis to Cr(VI) toxicity and its potential as a bioindicator for heavy metal contamination. Metal sorption was highest in 0.5ppm Cr(VI) with 56.56% removal. Notably, at lower concentrations, Cr(VI) acted as an intermediate electron acceptor, enhancing the electron transport chain and potentially increasing biomass under controlled conditions. The findings underscore the importance of understanding the mechanisms underlying heavy metal stress in microalgae for effective environmental remediation strategies. The research highlights the dual role of chromium(VI) in influencing S. platensis, depending on the concentration, and underscores the importance of understanding metal ion interactions with photosynthetic organisms for potential applications in bioremediation.

The Impact of Cr(III) and Cr(VI) on Lipid Accumulation in Chlorella pyrenoidosa

In this study, Chlorella pyrenoidosa was cultured with different concentrations of Cr(III) and Cr(VI), and the changes in biomass, lipid content, protein content and total sugar content of Chlorella pyrenoidosa under different culture conditions were detected. The effects of Cr(III) and Cr(VI) on the intracellular antioxidant system and related key enzymes of lipid synthesis were analyzed. The results showed that appropriate Cr(III) and Cr(VI) concentrations could make Chlorella pyrenoidosa regulate the contents of SOD, POD, ASA, CAT and GSH in cells, improve the enzyme activity of ACC and promote lipid synthesis. The aim was to investigate the mechanism of lipid synthesis by analyzing the distribution of Cr(III) and Cr(VI) in algal cells. The lipid content of Chlorella pyrenoidosa reached its highest level at 50.43 wt% and 38.00 wt% when both Cr(III) and Cr(VI) concentrations in the culture environment were 0.5 mg/L. These values were 1.37 and 1.03 times higher than the control group, respectively. The addition of appropriate Cr(III) and Cr(VI) concentrations can increase ME enzyme activity and decrease PEPC enzyme activity, shorten the biomass accumulation cycle and prolong the lipid synthesis cycle.

Effective fixation of Cu(II) and Cr(III) in solution by food waste biochar – Innovative and valuable treatment method for municipal solid waste

Enhancing biochar's adsorption and solidification performance in compound-polluted aqueous solutions remains a crucial task for achieving the cost-effective removal of heavy metals from water bodies. The study examined the removal performances and mechanisms of Cu(II) and Cr(III) using biochar prepared from food waste at temperatures of 350 °C, 450 °C, and 550 °C (FWB-350, FWB-450, and FWB-550). FWB-450 exhibited the highest overall effectiveness in adsorbing Cu(II) and Cr(III), demonstrating the adsorption capacity (Qe) of 40.283 and 21.456 mg/g in single-solution, respectively. Thermodynamic parameters indicate that the adsorption process involves physical and chemical reactions involving heat absorption. The impact of Cr(III) on the adsorption of Cu(II) is more apparent in the mixed competitive system. The pH, the oxygen-functional groups and carbonate ion quantity of FWB are crucial in improving Cu(II) and Cr(III) adsorption by affect the hydrolysis, complexation, and ion exchange processes. The presence of alkaline earth metal ions in FWB, like Ca(II), aids in the elimination of Cu(II) and Cr(III) through ionic precipitation and ion exchange, correspondingly. Furthermore, FWB adsorbed with Cu(II) and Cr(III) is relatively less hazardous than solid waste. The study validates the resource utilization of FW and its potential application of biochar in heavy metal adsorption.

Enhanced Redox Cycle of Rod-Shaped MIL-88A/SnFe2O4@MXene Sheets for Fenton-like Degradation of Congo Red: Optimization and Mechanism.

This study intended to fabricate a novel Fenton-like catalyst by supporting the rod-like MIL-88A and the magnetic tin ferrite nanoparticles (SnFe2O4) on the MXene sheets (MIL-88A/SnFe2O4@MXene). The well fabrication and determination of the MIL-88A/SnFe2O4@MXene properties were investigated using SEM, XPS, VSM, Zeta potential, XRD, and FTIR tools. The Fenton-like degradation reaction of CR by MIL-88A/SnFe2O4@MXene was thoroughly studied to identify the optimal proportions of the catalyst components, the impact of CR and H2O2 concentrations, as well as the effect of raising the temperature and the pH medium of the catalytic system and the catalyst dosage. Kinetics studies were executed to analyze the decomposition of CR and H2O2 using First-order and Second-order models. Furthermore, the degradation mechanism was proposed based on the scavenging test that proceeded in the presence of chloroform and t-butanol, in addition to the XPS analysis that clarified the participation of the containing metal species: Fe, Sn, and Ti, and the formation of a continual redox cycle. The obtained intermediates during the CR degradation were defined by GC-MS. A recyclability test was performed on MIL-88A/SnFe2O4@MXene during five runs of the Fenton-like degradation of CR molecules. Finally, the novel MIL-88A/SnFe2O4@MXene Fenton-like catalyst could be recommended as a propitious heterogeneous catalyst with a continuous redox cycle and a recyclability merit.

Comparative research on the interfacial properties of Ni/diamond and Ni/graphene interface with Cr, B, and Si additions by first-principles calculation

Diamond and graphene (Gr) with excellent hardness and strength are the ideal reinforcement for WC-based ceramics due to the wear resistance and toughness enhancement effect. For the promising diamond-graphene/WC-Ni composite, one of the major challenges is the intrinsic difference of interfacial bonding mechanism between diamond/Ni and graphene/Ni interfaces that makes it difficult to obtain desired mechanical bonding properties simultaneously. To address this issue, the adhesion and electronic properties of the Ni (111)/diamond (111) and Ni (111)/graphene (001) interfaces, together with the impact of Cr, B, and Si doping on the mechanical and fracture properties of the interfaces are analyzed comparatively through first-principles calculations in this work. Adhesion energy calculations demonstrate that the bonding strength of Ni/diamond interface is 4.5 times greater than that of Ni/Gr interface, and the addition of Cr and B atoms can increase the adhesion energy of Ni/diamond interface by 19.6 % and 36.7 %, and Ni/Gr interface by 284 % and 222 % respectively. Moreover, the calculations of electron density, charge density difference, and density of states suggest that Cr and B atoms facilitate the establishment of stronger chemical bonds at the interface. First-principles computational tensile tests show the tensile strength of Ni/diamond and Ni/Gr increases separately by 1.5 % and 62.2 % after Cr doping, and the tensile strength of Ni/diamond models is 2.5 times greater than that of Ni/Gr models.

Impact of Cr–O hybridization in ACrO3 (A = La, Y): A theoretical investigation

Electronic properties of spin polarized antiferromagnetic ACrO3 (A = La, Y) are explored with Hubbard model using density functional theory (DFT). These two isostructural systems are investigated using the different Hubbard energy and analyzed the hybridization of chromium 3d orbitals and oxygen 2p orbitals and the change in energy bandgaps against the Hubbard energy. The bond length and bond angle affect significantly the orbital contributions of Cr-3d and O-2p electrons for both the system. We noticed that the Cr–O hybridization affects the orbital degeneracy and is substantiated with partial density of states. These results emphasize the contribution of Hubbard energy in correlated electron systems.

Counter Effect of Trichoderma harzianum Rifai. Against Cr (VI)

Industrial and sewage water ejection in river and streams on daily basis and wide use of heavy metal is contaminating our surroundings. Among all the valences, Cr (VI) is regarded as a hazardous ion, which contaminates groundwater and can be transferred through the food chain In-vitro study was carried out in laboratory in which impact of Cr (VI) on Trichoderma harzianum was studied. For those two experiments i.e., solid medium assay and liquid broth assay were conducted. In solid medium assay, the radial growth, morphological alterations (appearance of colony, changes in the morphologies of spores and hyphae) in T. harzianum and inhibition zone under the stress of Cr (VI) at different doses i.e., 0, 1000, 2000, 3000, 4000 and 5000 ppm were studied. The results showed that radial growth was insignificantly reduced at highest dose (5000 ppm) i.e., 3.3% as compared to control. Moreover, no inhibition zone formed, and the mycelial pattern of tested fungi was crossing the disc zones. However, at 5000 ppm of Cr (VI), about 0.2 mm of concentric zone was observed. While no phialides were observed at higher doses of Cr (VI). Furthermore, in liquid broth experiment, mycelial growth, and biochemical attributes [Total protein content (TPC), Peroxidase (POX) and Catalase (CAT) activities] were studied after 7 days of incubation. The results revealed that the fresh and dry weight of T. harzianum was increased up to -200% comparison to control. The level of TPC, POX AND CAT increased by -10 % to -94% with the increasing concentration of Cr (VI) i.e., 1000 to 5000 ppm. Thus, the findings showed that T. harzianum could be used as bioremidier against Cr (VI). Further in- situ studies need to be taken to eradicate the presence of heavy metals in the environment by using fungus for bioremediation purpose in future.

Green rust sulfate transformation under the impact of Cr(VI) and oxalic acid: Mechanism and environmental significance

Green rust (GR), as one of mixed-valent iron [Fe(II)-Fe(III)] minerals, has received a significant attention in recent years because it is an intrinsic and essential part of biogeochemical cycling of heavy metals and DOM. The transformation of GR is a key factor in altering the environmental behavior of heavy metals, and therefore, prediction of such transformation is critical for managing environmental quality. DOM and heavy metals are recognized to have a significant impact on iron oxide transformation. However, detailed information on these phenomena and mechanisms are still limited. In this study, Cr(VI) and oxalic acid (OA) widely distributed in the natural environment were selected representatives of heavy metals and DOM. The mechanism of their influence on GR transformation and their environmental significance were clarified. GR transformed to feroxyhyte under the impact of Cr(VI) and OA, and feroxyhyte did not transform to more crystalline iron oxides after 7 days. However, OA enhanced Fe dissolution and Cr(VI) reduction while weakening the immobilization of Cr on GR. SEM results demonstrated that OA addition resulted in the collapse of the feroxyhyte structure. SEM-EDS data indicated that Cr and OA were adsorbed on GR, suggesting that this can be an essential pathway for C and Cr sequestration during GR transformation. This study reveals Cr(VI) not only favors the formation of feroxyhyte, but also stabilizes the mineral to prevent transformation and meanwhile indicates the mechanisms of organic matter interactions with iron oxide and the environmental behavior of C and Cr during the iron oxide transformation processes.

Degradation and recovery of solid oxide fuel cell performance by control of cathode surface acidity: Case study – Impact of Cr followed by Ca infiltration

Solid oxide fuel cells (SOFCs) have attracted attention as clean and efficient energy conversion devices with low emissions. However, several degradation mechanisms limit the electrochemical performance of current SOFCs, with cathode degradation due to Cr-poisoning from metal interconnects particularly problematic. The acidity/basicity of binary additives has been found to be a sensitive descriptor of the oxygen exchange kinetics, indicating that acidic Cr-species/basic Ca-species can be expected to deactivate/activate the cathode surface, respectively. Inspired by recent advances, the feasibility of relative acidity as a tool for reviving degraded SOFCs is demonstrated by neutralizing Cr-poisoned SOFCs by subsequent serial infiltration of Ca-species. A model mixed ionic and electronic conducting oxide, Pr0.1Ce0.9O2-δ (PCO), is selected as the cathode material. Area-specific resistances (ASR) of symmetric cells obtained by electrochemical impedance spectroscopy show that Cr-infiltration results in a seven-fold increase in ASR, while subsequent infiltration of Ca-species leads to complete recovery. Performance degradation and recovery are attributed to depressed/enhanced redox properties at the PCO surface, as supported by XPS analysis. Experiments using anode-supported fuel cells show a reduction in peak power density by 26% upon Cr-infiltration, reversed following Ca-infiltration, after which no degradation is observed during subsequent operation for 100 h.

Phytoremediation of potentially toxic elements and rare earth elements by perennial plants in floating wetlands

The impact of urbanization, industrialization, agriculture, mining, and stormwater runoff on ecosystems has resulted in significant water pollution concerns worldwide. Significant attention has been paid to the removal of potentially toxic elements (PTE) and metalloids (e.g., arsenic (As), selenium (Se) and lead (Pb)) by various plant species. However, little research has been published on the simultaneous accumulation of cadmium (Cd), chromium (Cr), and nutrient removal, by floating treatment wetlands (FTW), from stormwater runoff, and the accumulation and recovery of rare earth elements (REE) through energy biomass cultivation. This research bridges knowledge gaps in the remediation of REE using short-rotation willow (Salix spp.) and simulated stormwater remediation of Cd and Cr with Phragmites australis and Iris pseudacorus. In this context, three different microcosm experiments were conducted with perennial plants (P. australis and I. pseudacorus) in FTW. Stem growth, dry biomass, root length, chlorophyll content index (CCI), anatomical plant tissue changes, Cd accumulation and N and P removal from simulated stormwater were investigated over a 50-days period under different Cd doses (0, 1, 2 and 4 mg L−1). In addition, the effects of Cr dose (0, 500, 1000 and 2000 μg L−1) on the growth and anatomy of P. australis and I. pseudacorus, as well as on the accumulation of Cr in plant biomass and N and P removal were studied in FTW over a 50-day period. In addition, the effects of REE doses on stem growth, dry biomass, root length and their accumulation in biomass were investigated in two Salix species (S. myrsinifolia and S. schwerinii) and two cultivars (Klara and Karin) in FTW over a 28-day period. The REE treatments contained a single-dose of lanthanum (La: 50 mg L−1), multi-solute of six-REE (La: 11.50 mg L−1 + yttrium (Y: 11 mg L−1) + neodymium (Nd: 10.50 mg L−1) + dysprosium (Dy: 10) + cerium (Ce: 12 mg L−1) + terbium (Tb: 11.50 mg L−1)) and control (without REE). Moreover, REE recovery from biomass ash after combustion was investigated. In this study, P. australis and I. pseudacorus growth parameters were not hampered by Cd stress, their roots accumulated more Cd than the shoots and were capable of lowering N and P concentrations. The impact of Cr was more evident on plant growth under the low- and medium doses (500 and 1000 μg Cr L−1). However, anatomical changes were observed under the high dose (2000 μg Cr L−1, respectively). Both species were able to remove a substantial (98−99%) concentration of N and P within a 10-day period of increased Cr loading. The greatest amount of Cr was retained in P. australis and I. pseudacorus roots. Salix species and cultivars did not show REE toxicity symptoms and displayed a strong growth response compared to the control. All Salix accumulated REE in their biomass, although the greatest amounts of accumulated REE were found in the roots of the Klara and Karin cultivars. The substantial deposition of Cd and Cr in the roots of P. australis and I. pseudacorus, and REE in the Salix roots show their phytostabilization potential. Approximately 80% of the REE was retained in the Salix ash following combustion of the biomass at 1000 °C. The findings in this research reveal that these perennial plants could be suitable candidates to control the runoff from Cd, Cr and REE affected waterbodies into freshwater resources through immobilization aligned with efficient biomass production.

International Working Group (IWG) Response Criteria and Association with Overall Survival in Patients with Myelodysplastic Syndromes Treated with Hypomethylating Agents - a Systematic Review and Meta-Analysis

* A.M.Z. and M.S. contributed equally Introduction: Response assessments in clinical trials and routine practice for patients (pts) with myelodysplastic syndromes (MDS) treated with hypomethylating agents (HMA) are based on the International Working Group (IWG) criteria proposed in 2000 and revised in 2006. However, it is not clear whether response criteria correlate with overall survival (OS). Methods: We conducted a systematic review and meta-analysis according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines with a systematic search using controlled vocabulary and free text terms for MDS and survival of Cochrane Library, Google Scholar, Ovid Embase, Ovid Medline, Pubmed, Scopus, and Web of Science Core Collection databases to find relevant articles published from inception to January 2022. The search was peer-reviewed by a second medical librarian. A targeted search of recent conference proceedings was also performed. Titles, abstracts, and full texts were reviewed for inclusion in the meta-analysis by two reviewers independently and conflicts were resolved by consensus discussion. Clinical trials and cohort studies with >100 pts reporting on the association of IWG 2000 or 2006 response criteria with OS among pts treated with HMA monotherapy or combinations were eligible for inclusion. Studies were excluded if they were (i) review or basic research articles, (ii) studies with <50% higher-risk MDS pts (inclusion of a minority of pts with MDS/MPN, oligoblastic AML, and lower-risk MDS was permitted), (iii) not published in English, and (iv) had insufficient reporting of the primary endpoint. The primary endpoint was the hazard ratio (HR) for OS for patients achieving an IWG-defined response (complete remission [CR], marrow CR, partial remission, hematologic improvement [HI]) compared to patients not achieving a response. Random-effects models were used to pool the HRs for death. Cochran Q and I2 indices were used to assess heterogeneity across included studies. Study heterogeneity was graded based on I2 indices as low (I2 <30%), moderate (I2 =30-60%), or high (I2 >60%). Comprehensive Meta-Analysis (CMA version 2.2, Biostat) was used for all analyses. Results: Our search strategy identified 7023 studies after duplicate removal. Following abstract and title review to identify clinical trials and large cohort studies reporting IWG response and OS among MDS pts treated with HMA, 195 studies were assessed for eligibility as full texts. Among these 185 studies were excluded for the following reasons: insufficient reporting of the primary outcome of OS and IWG response (n=114), duplicate publications from the same pt cohort (n=42), <50% higher-risk MDS pts (n=13), cohort studies with <100 pts (n=6), not on HMA therapy (n=4), ongoing clinical trials without published results (n=3), transplant (n=2), and review article (n=1). The final set of studies included 3896 MDS pts treated with azacitidine, decitabine, guadecitabine, or HMA-combination in 9, 4, 1, and 2 studies, respectively. Among the 5 available studies with data on the impact of CR on OS, the HR for death was 0.365 (95% CI: 0.311-0.430) for pts who achieved a CR compared to pts without a CR. Study heterogeneity was low (Cochran's Q=0.5; I2=0%; Figure A). Six studies reported the impact of HI on OS. Pts who achieved HI had favorable outcomes compared to pts without HI (HR: 0.419; 95% CI: 0.299-0.585) but with high heterogeneity across studies (Cochran's Q=14.34; I2=65.13%; Figure B). The prognostic impact of other response categories (e.g., marrow CR, partial remission) was only reported by 1 study each, precluding a meta-analysis. Conclusion: Achieving CR as defined by the IWG MDS response criteria is associated with improved OS among higher-risk MDS pts treated with HMA-based regimens. HI was also associated with OS, but with high study heterogeneity. The strong and consistent association of CR with OS supports its use as an outcome in clinical trials in MDS. The prognostic implications of other response categories as such CR with partial hematologic recovery (CRh) especially with novel combination therapies require additional studies. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

THE EFFECT OF COMPANY PERFORMANCE ON FIRM VALUE WITH INSTITUTIONAL OWNERSHIP AS AN INTERVENING VARIABLE (AN EMPIRICAL STUDY ON REAL ESTATE AND PROPERTY COMPANIES REGISTERED IN INDONESIAN STOCK EXCHANGE 2016-2019)

The aims of this research is to analyze the impact of Current Ratio and ROA on Company Value with Institutional Ownership as an intervening variable with Empirical Studies on property and real estate companies registered on the IDX in 2016 – 2019.This study used quantitative descriptive method, where the data is measured on a numerical scale with the secondary data,.This study result is Institutional Ownership had not affected significantly by Current Ratio with a t-statistic of 0.883318 and firm value also not significantly affected by CR with a t-statistic of -0.712988, while Institutional Ownership not affected significantly by ROA rwith a t-statistic of 0.303315, but ROA affected significantly by ROA with a t-statistic of 3.088025 and institutional ownership not impacted significantly on firm value with a t-statistic of -0.651118.Also, Current Ratio and ROA simultaneously non affect on Institutional Ownership, but simultaneously there is a significant impact of Institutional Ownership, ROA, and Current Ratio, firm value. Based on the intervening test, can be say that institutional ownership is not able to mediate the impact of CR and ROA on company value.

Combined Effect of Compression Ratio and Fuel Injection Pressure on CI Engine Equipped with CRDi System Using Prosopis juliflora Methyl Ester/Diesel Blends

The exhaustion of worldwide oil reserves has created an incipient need to find hopeful alternative fuels for the future. Substantial research has been done in this direction, and all studies by researchers have provided results that proved the growing potential of biofuel as a popular alternative in the CI engine. The current investigation explores the biofuel potential derived from the wasteland tree Prosopis juliflora (Karuvalam tree seeds). Experimentation was done using a monocylinder 4-stroke water-cooled six holes CRDi CI engine with electrical loading. The experiment was conducted at three proportions (10%, 20%, and 30% volume basis) of Prosopis juliflora Oil Methyl Ester (PJOME) with diesel using 3 parametric CRs (16, 17.5, and 19) along with three different fuel injection pressure (FIP) (400, 500, and 600 bar). The impact of CR and FIP on fuel utilization BTE, cylinder pressure, net heat release, and exhaust particulates was scrutinized and characterized. The test results demonstrated that increasing the compression ratio from 16 to 19 enhanced the in-cylinder pressure, net heat release (NHR), and BTE for all the (PJOME/Diesel) combinations. With an augmentation in the compression ratio from 16 to 19, carbon monoxide and unburnt hydrocarbon discharge diminished, but the nitrogen oxide discharges augmented. FIP also had an impact of increasing the pressures on the in-cylinder, NHR, brake thermal efficiency, and nitrogen oxide and reducing the emissions of smoke, CO, and UBHC. The current research shows that the use of B20 and CR16 and FIP 600 bar as a combination improved BTE by 33.21%, BSFC by 0.25 kg/kw-hr, cylinder pressure at the maximum to reach 69.28 bar, net heat release of 79.14 J/deg, and exhaust emissions such as UHC at 55 ppm, CO at 0.25%, smoke at 34.33%, and NOx at 2401 ppm. Finally, the BTE and NOx were slightly higher, and the UHC, CO, and smoke values were diminutive compared to other blends.

Energy band gap tuning of Ba₁˗ₓZnₓFe₁₂‐yCrʏO₁₉ doped with Cr and Zn ions to enhance the optical, dielectric, ferroelectric, and photocatalytic properties

In the current investigation, the fabrication of chromium (Cr) and zinc (Zn) doped barium hexaferrite nanoparticles (Ba₁˗ₓZnₓFe₁₂‐yCrʏO₁₉ NPs) using facile microemulsion route was undertaken. The impact of Cr and Zn doping on photocatalytic, structural, ferroelectric and dielectric properties was investigated. The X-ray diffraction (XRD) analysis revealed the formation of hexagonal ferrite structure of Ba₁˗ₓZnₓFe₁₂‐yCrʏO₁₉ NPs. The size of the NPs was in the range of 17–26 nm with tendency to form aggregates. The band gap of barium hexaferrite was increased with doping contents due to difference in ionic radii of dopants. The polarization-electric (P-E) field loops confirmed the ferroelectric behavior of synthesized Ba₁˗ₓZnₓFe₁₂‐yCrʏO₁₉ NPs. The photocatalytic activity (PCA) of Ba₁˗ₓZnₓFe₁₂‐yCrʏO₁₉ NPs was evaluated for Rhodamine B (RhB) dye removal under solar light irradiation and up to 81.8% dye degradation was observed within 90 min of irradiation. Results revealed that catalytic, ferroelectric and dielectric properties of barium hexaferrite can be enhanced with Cr and Zn doping for different applications.

Cr (VI)-induced oxidative damage impairs ammonia assimilation into organic forms in Solanum lycopersicum L.

Chromium (Cr) is a dangerous metal that has been found in the environment in high amounts as the result of numerous human activities, with proven negative effects on various organisms, including plants. The exposure of some plant species to this metal resulted in reduced growth, impaired nutrient uptake, and led to an overproduction of reactive oxygen species (ROS), ultimately causing oxidative damage. Nevertheless, studies regarding the impact of Cr on nitrogen (N) metabolism, the main limiting factor for plant growth, either directly or through the occurrence of oxidative stress, are scarce. Thus, this work aimed to explore the interplay between ammonia (NH4+) assimilation, redox homeostasis and antioxidant (AOX) system of tomato plants exposed to increased concentrations of Cr (VI) (0, 5 and 10 µM). The results revealed that Cr (VI) induced biometric damages, with roots being the most affected organ. Glutamine synthetase (GS) was differentially influenced by the metal at the gene expression, protein and activity levels, whereas glutamate dehydrogenase (GDH) activity was enhanced. Moreover, in Cr (VI)-treated plants, the observed oxidative damage was dependent on metal concentration and plant organ, with a differential accumulation of ROS and a generalized increase of lipid peroxidation (LP) recorded, being paired with an overall failure of the enzymatic antioxidant (AOX) system. Still, the non-enzymatic AOX component had a relevant role in the protection of plants against Cr (VI). Overall, the obtained results suggest that Cr (VI)-mediated plant growth reduction resulted from the occurrence of oxidative stress, coupled with the lack of enzymatic AOX defense, which, consequently, affected the NH4+ assimilatory route.

Pengaruh CR dan DER terhadap ROE pada Perusahaan Jasa Sub Sektor Konstruksi dan Bangunan

This research aims to determine how much the impact of CR and DER on ROE at Heavy Constructions and Civil Engineering companies for the period 2014-2019. Sample used were 8 companies using purposive sampling technique. The data used in this study is panel data so that the data will be tested using the help of Eviews 9 application and analysed using panel data regression. The selected panel data regression model is the Random Effect Model. The results of the analysis show that the CR variable partially negatively has no significant effect towards the ROE with a significance level of 0.9427 meanwhile the DER variable partially has a positive significant effect towards the ROE with a significance level of 0.0191. While simultaneous CR and DER variables affect ROE with a coefficient of determination of 15.42%

Abstract 2357: Anticancer effects of calorie restriction in a murine C3-TAg model of triple-negative breast cancer: the role of miR-15b

Abstract Calorie restriction (CR) has an antitumorigenic effect against triple-negative breast cancer (TNBC). A key mitogenic pathway modulated by CR involves insulin-like growth factor (IGF)-1, which plays a central role in local and systemic growth and cell survival by activating the PI3K/AKT/mTOR pathway downstream of the IGF-1 receptor (IGF-1R). Although multiple miRNAs that target components of the IGF-1 signaling pathway have been identified, the impact of CR on IGF-1-related miRNA expression has not been addressed. We hypothesize that CR-induced decreases in TNBC development and progression involve miRNA's regulating IGF-1 signaling, we used C3(1)/SV40 T-antigen (C3-TAg) mice (a TNBC model), a C3-Tag progression series of cell lines (M28, M6, and M6C), and human TNBC cell line (MDA-MB-231). The expression of miRNAs previously reported to target components of the IGF-1 and/or mTOR pathways was evaluated by real-time PCR. Hormone levels were measured using the mouse Luminex Screening Assay. To mimic CR in vitro, and to test the effects of miRNA manipulation, the C3-Tag series of TNBC cell lines were treated (separately and in combination) with serum restriction, BMS754807 (inhibitor of IGF1-R), and various levels of recombinant IGF-1 as well as manipulated levels of miRNA's associated with IGF-1/mTOR signaling. We also conducted in silico analysis using Metabric, TCGA, TargetScan, and miRTarBase data sets to identify genes and pathways associated with specific miRNAs expression related to the PI3K/Akt/mTOR pathway. Our results confirm that CR maintains lower body weight, reduces circulating levels of IGF-1, and slows spontaneous TNBC development and progression in mice. CR also significantly increased the expression of miR-15b and miR-486. In vitro studies showed miR-15b and miR-486 expression decreased with increasing tumorigenicity of the C3-tag series of TNBC progression. Treatment of mouse and human TNBC cells with low IGF-1 induced miR-15b expression and inhibited proliferation. Moreover, miR-15b overexpression inhibited cell proliferation and decreased IGF-1R expression (mRNA and protein). Consistent with these results, the in silico analysis shows that the amplification of miR-15b correlates with downregulation of pathways involved in tumor growth and IGF1-R signaling. Together these findings suggest that reduced circulating IGF-1 levels in response to CR leads to the upregulation of miR-15b, which correspondingly targets and downregulates IGF-1R, both at the mRNA and protein levels. This combination of reduced IGF-1 ligand and miR-15b-induced IGF-1R downregulation contributes to the potent anticancer effects of CR and reveals potential targets for pharmacologically mimicking those effects. This research is supported by R35CA197627. Citation Format: Ximena Minerva Bustamante-Marin, Kaylyn L. Devlin, Om Dave, Jenna L. Merlino, Shannon B. McDonell, Michael F. Coleman, Stephen D. Hursting. Anticancer effects of calorie restriction in a murine C3-TAg model of triple-negative breast cancer: the role of miR-15b [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2357.

Impact of cardiac rehabilitation on mortality and morbidity in diabetic versus non-diabetic patients: protocol for a systematic review and meta-analysis

BackgroundCardiac rehabilitation (CR) decreases the morbidity and mortality risk among patients with cardiac diseases; however, the impact of CR on patients with diabetes remains underexplored. This is a protocol for...

Remediation of hexavalent chromium contaminated water through zero-valent iron nanoparticles and effects on tomato plant growth performance

Contaminated water with hexavalent chromium Cr(VI) is a serious environmental problem. This study aimed to evaluate the Cr(VI) removal by zero valent iron nanoparticles (nZVI) reduction process and the impact of Cr(VI), nZVI and combined treatment with nZVI and Cr(VI) on tomato growth performance. To evaluate the Cr(VI) toxic effect on germination capability, seeds were exposed to increasing Cr(VI) concentrations up to 1000 mg L−1. The inhibition of seed germination and the decrease of hypocotyl and root length started from Cr(VI) 5 mg L−1. Under treatment with Cr(VI) + nZVI 5 mg L−1, seed germination, hypocotyl and root length resulted significantly higher compared to Cr(VI) 5 mg L−1 treatment. The impact of only nZVI was investigated on chlorophyll and carotenoid in leaves; iron levels in leaves, roots, fruits and soil; carotenoid, fat-soluble vitamin and nicotianamine in mature fruits. A significant increase of leaf chlorophyll and carotenoids was observed after nZVI 5 mg L−1 treatment compared to controls. No significant variations were observed in carotenoids, fat-soluble vitamins and nicotianamine levels after treatment with nZVI 5 mg L−1 in mature fruits. For their ability to reduce Cr(VI) and to stimulate tomato growth, nZVI might to be considered as alternative for remediation purposes.