Review of the pharmacological management of hepatitis B viral infection before and after liver transplantation

The progress in treatment against hepatitis B virus(HBV)with the development of effective and well tolerated nucleotide analogues(NAs)has improved the outcome of patients with HBV decompensated cirrhosis and has prevented post-transplant HBV recurrence.This review summarizes updated issues related to the management of patients with HBV infection before and after liver transplantation(LT).A literature search using the PubMed/Medline databases and consensus documents was performed.Pre-transplant therapy has been initially based on lamivudine,but entecavir and tenofovir represent the currently recommended first-line NAs for the treatment of patients with HBV decompensated cirrhosis.After LT,the combination of HBV immunoglobulin(HBIG)and NA is considered as the standard of care for prophylaxis against HBV recurrence.The combination of HBIG and lamivudine is related to higher rates of HBV recurrence,compared to the HBIG and entecavir or tenofovir combination.In HBIG-free prophylactic regimens,entecavir and tenofovir should be the first-line options.The choice of treatment for HBV recurrence depends on prior prophylactic therapy,but entecavir and tenofovir seem to be the most attractive options.Finally,liver grafts from hepatitis B core antibody(anti-HBc)positive donors can be safely used in hepatitis B surface antigen negative,preferentially anti-HBc/anti-hepatitis B surface antibody positive recipients.

Assessment of correlation between serum titers of hepatitis c virus and severity of liver disease

AIM:The significance of hepatitis C virus (HCV) serum titers has been examined in several clinical situations. There is much evidence that patients with a lower viral load have better response rates to anti-viral therapy compared to those with higher levels.Moreover,a direct association has been observed between serum titers of HCV and transmission rates of the virus.The aim of the present study was to determine if there was any correlation between HCV viral load and the severity of liver disease. METHODS:Fifty patients with HCV infection were included in the study.These comprised of 34 subjects with a history of alcohol use and 16 non-alcoholics.Quantitative serum HCV RNA assay was carried out using the branched DNA (bDNA) technique.Linear regression analysis was performed between serum viral titers and liver tests.In addition,for the purpose of comparison,the subjects were divided into two groups:those with low viral liters (≤50 genome mEq/mL) and high titers (>50 mEq/mL). RESULTS:All subjects were men,with a mean±SD age of 47±7.8 years.The mean HCV RNA level in the blood was 76.3×10~5±109.1 genome equivalents/mL.There was no correlation between HCV RNA levels and age of the patients (r=0.181),and the history or amount (g/d) of alcohol consumption (r=0.07).Furthermore,no correlation was observed between serum HCV RNA levels and the severity of liver disease as judged by the values of serum albumin (r=0.175),bilirubin (r=0.217),ALT (r=0.06) and AST (r=0.004) levels.Similarly,no significant difference was observed between patients with low viral titers and high liters with respect to any of the parameters. CONCLUSION:Our results indicate that the severity of liver disease is independent of serum levels of hepatitis C virus.These findings are important since they have a direct impact on the current debate regarding the role of direct cytopathic effect of hepatitis C virus versus immune-mediated injury in the pathogenesis of HCV-related liver damage.

Lithium-ion and solvent co-intercalation enhancing the energy density of fluorinated graphene cathode

Fluorinated carbons CF_xhold the highest theoretical energy density(e.g.,2180 W h kg^(-1)when x=1)among all cathode materials of lithium primary batteries.However,the low conductivity and severe polarization limit it to achieve its theory.In this study,we design a new electrolyte,namely 1 M LiBF_(4)DMSO:DOL(1:9 vol.),achieving a high energy density in Li/CF_xprimary cells.The DMSO with a small molecular size and high donor number successfully solvates Li^(+)into a defined Li^(+)-solvation structure.Such solvated Li^(+)can intercalate into the large-spacing carbon layers and achieve an improved capacity.Consequently,when discharged to 1.0 V,the CF_(1.12)cathode demonstrates a specific capacity of 1944 m A h g^(-1)with a specific energy density of 3793 W h kg^(-1).This strategy demonstrates that designing the electrolyte is powerful in improving the electrochemical performance of CF_(x) cathode.

AI-Powered Innovations in High-Tech Research and Development: From Theory to Practice

This comparative review explores the dynamic and evolving landscape of artificial intelligence(AI)-powered innovations within high-tech research and development(R&D).It delves into both theoreticalmodels and practical applications across a broad range of industries,including biotechnology,automotive,aerospace,and telecom-munications.By examining critical advancements in AI algorithms,machine learning,deep learning models,simulations,and predictive analytics,the review underscores the transformative role AI has played in advancing theoretical research and shaping cutting-edge technologies.The review integrates both qualitative and quantitative data derived from academic studies,industry reports,and real-world case studies to showcase the tangible impacts of AI on product innovation,process optimization,and strategic decision-making.Notably,it discusses the challenges of integrating AI within complex industrial systems,such as ethical concerns,technical limitations,and the need for regulatory oversight.The findings reveal a mixed landscape where AI has significantly accelerated R&D processes,reduced costs,and enabled more precise simulations and predictions,but also highlighted gaps in knowledge transfer,skills adaptation,and cross-industry standardization.By bridging the gap between AI theory and practice,the review offers insights into the effectiveness,successes,and obstacles faced by organizations as they implement AI-driven solutions.Concluding with a forward-looking perspective,the review identifies emerging trends,future challenges,and promising opportunities inAI-poweredR&D,such as the rise of autonomous systems,AI-driven drug discovery,and sustainable energy solutions.It offers a holistic understanding of how AI is shaping the future of technological innovation and provides actionable insights for researchers,engineers,and policymakers involved in high-tech Research and Development(R&D).

Blast waveform tailoring using controlled venting in blast simulators and shock tubes

A critical challenge of any blast simulation facility is in producing the widest possible pressure-impulse range for matching against equivalent high-explosive events.Shock tubes and blast simulators are often constrained with the lack of effective ways to control blast wave profiles and as a result have a limited performance range.Some wave shaping techniques employed in some facilities are reviewed but often necessitate extensive geometric modifications,inadvertently cause flow anomalies,and/or are only applicable under very specific configurations.This paper investigates controlled venting as an expedient way for waveforms to be tuned without requiring extensive modifications to the driver or existing geometry and could be widely applied by existing and future blast simulation and shock tube facilities.The use of controlled venting is demonstrated experimentally using the Advanced Blast Simulator(shock tube)at the Australian National Facility of Physical Blast Simulation and via numerical flow simulations with Computational Fluid Dynamics.Controlled venting is determined as an effective method for mitigating the impact of re-reflected waves within the blast simulator.This control method also allows for the adjustment of parameters such as tuning the peak overpressure,the positive phase duration,and modifying the magnitude of the negative phase and the secondary shock of the blast waves.This paper is concluded with an illustration of the potential expanded performance range of the Australian blast simulation facility when controlled venting for blast waveform tailoring as presented in this paper is applied.

Immunomodulatory activity of polycaprolactone nanoparticles with calcium phosphate salts against Leishmania infantum infection

Objective:To prepare and characterize polycaprolactone(PCL)nanoparticles loaded with sonicator fragmented(SLA)and freeze-thaw Leishmania antigens(FTLA)and to investigate the in vitro immunogenicity of antigen-encapsulated nanoparticles with calcium phosphate adjuvant.Methods:The water/oil/water binary emulsion solvent evaporation method was used to synthesize antigen-loaded PCL nanoparticles.Particles were characterized by scanning electron microscopy and zeta potential measurements.Their cytotoxicity in J774 macrophages in vitro was determined by MTT analysis.In addition,the amount of nitric oxide and the level of cytokines produced by macrophages were determined by Griess reaction and ELISA method,respectively.The protective effect of the developed formulations was evaluated by determining the infection index percentage in macrophages infected with Leishmania infantum.Results:Compared to the control group,SLA PCL and FTLA PCL nanoparticles with calcium phosphate adjuvant induced a 6-and 7-fold increase in nitric oxide,respectively.Additionally,the vaccine formulations promoted the production of IFN-γand IL-12.SLA PCL and FTLA PCL nanoparticles combined with calcium phosphate adjuvant caused an approximately 13-and 11-fold reduction in infection index,respectively,compared to the control group.Conclusions:The encapsulation of antigens obtained by both sonication and freeze-thawing into PCL nanoparticles and the formulations with calcium phosphate adjuvant show strong in vitro immune stimulating properties.Therefore,PCL-based antigen delivery systems and calcium phosphate adjuvant are recommended as a potential vaccine candidate against leishmaniasis.

Persistent occult hepatitis B virus infection:Experimental findings and clinical implications

Hepatitis B virus (HBV) is a highly pathogenic virus that causes chronic liver diseases in millions of people globally. In addition to a symptomatic, serologically evident infection, occult persistent HBV carriage has been identified since nucleic acid amplification assays of enhanced sensitivity became introduced for detection of hepadnaviral genomes and their replicative intermediates. Current evidence indicates that occult HBV infection is a common and long-term consequence of resolution of acute hepatitis B. This form of residual infection is termed as secondary occult infection (SOI). The data from the woodchuck model of HBV infection indicate that exposure to small amounts of hepadnavirus can also cause primary occult infection (POI) where virus genome, but no serological makers of exposure to virus, are detectable, and the liver may not be involved. However, virus replicates at low levels in the lymphatic system in both these forms. We briefly summarize the current understanding of the nature and characteristics of occult hepadnaviral persistence as well as of its documented and expected pathological consequences.

Posture Detection of Heart Disease Using Multi-Head Attention Vision Hybrid(MHAVH)Model

Cardiovascular disease is the leading cause of death globally.This disease causes loss of heart muscles and is also responsible for the death of heart cells,sometimes damaging their functionality.A person’s life may depend on receiving timely assistance as soon as possible.Thus,minimizing the death ratio can be achieved by early detection of heart attack(HA)symptoms.In the United States alone,an estimated 610,000 people die fromheart attacks each year,accounting for one in every four fatalities.However,by identifying and reporting heart attack symptoms early on,it is possible to reduce damage and save many lives significantly.Our objective is to devise an algorithm aimed at helping individuals,particularly elderly individuals living independently,to safeguard their lives.To address these challenges,we employ deep learning techniques.We have utilized a vision transformer(ViT)to address this problem.However,it has a significant overhead cost due to its memory consumption and computational complexity because of scaling dot-product attention.Also,since transformer performance typically relies on large-scale or adequate data,adapting ViT for smaller datasets is more challenging.In response,we propose a three-in-one steam model,theMulti-Head Attention Vision Hybrid(MHAVH).Thismodel integrates a real-time posture recognition framework to identify chest pain postures indicative of heart attacks using transfer learning techniques,such as ResNet-50 and VGG-16,renowned for their robust feature extraction capabilities.By incorporatingmultiple heads into the vision transformer to generate additional metrics and enhance heart-detection capabilities,we leverage a 2019 posture-based dataset comprising RGB images,a novel creation by the author that marks the first dataset tailored for posture-based heart attack detection.Given the limited online data availability,we segmented this dataset into gender categories(male and female)and conducted testing on both segmented and original datasets.The training accuracy of our model reached an impressive 99.77%.Upon testing,the accuracy for male and female datasets was recorded at 92.87%and 75.47%,respectively.The combined dataset accuracy is 93.96%,showcasing a commendable performance overall.Our proposed approach demonstrates versatility in accommodating small and large datasets,offering promising prospects for real-world applications.

Risk factors for hepatocellular carcinoma associated with hepatitis C genotype 3 infection:A systematic review

BACKGROUND Hepatitis C virus(HCV)is a blood-borne virus which globally affects around 79 million people and is associated with high morbidity and mortality.Chronic infection leads to cirrhosis in a large proportion of patients and often causes hepatocellular carcinoma(HCC)in people with cirrhosis.Of the 6 HCV genotypes(G1-G6),genotype-3 accounts for 17.9%of infections.HCV genotype-3 responds least well to directly-acting antivirals and patients with genotype-3 infection are at increased risk of HCC even if they do not have cirrhosis.AIM To systematically review and critically appraise all risk factors for HCC secondary to HCV-G3 in all settings.Consequently,we studied possible risk factors for HCC due to HCV-G3 in the literature from 1946 to 2023.METHODS This systematic review aimed to synthesise existing and published studies of risk factors for HCC secondary to HCV genotype-3 and evaluate their strengths and limitations.We searched Web of Science,Medline,EMBASE,and CENTRAL for publications reporting risk factors for HCC due to HCV genotype-3 in all settings,1946-2023.RESULTS Four thousand one hundred and forty-four records were identified from the four databases with 260 records removed as duplicates.Three thousand eight hundred and eighty-four records were screened with 3514 excluded.Three hundred and seventy-one full-texts were assessed for eligibility with seven studies included for analysis.Of the seven studies,three studies were retrospective case-control trials,two retrospective cohort studies,one a prospective cohort study and one a cross-sectional study design.All were based in hospital settings with four in Pakistan,two in South Korea and one in the United States.The total number of participants were 9621 of which 167 developed HCC(1.7%).All seven studies found cirrhosis to be a risk factor for HCC secondary to HCV genotype-3 followed by higher age(five-studies),with two studies each showing male sex,high alpha feto-protein,directly-acting antivirals treatment and achievement of sustained virologic response as risk factors for developing HCC.CONCLUSION Although,studies have shown that HCV genotype-3 infection is an independent risk factor for end-stage liver disease,HCC,and liver-related death,there is a lack of evidence for specific risk factors for HCC secondary to HCV genotype-3.Only cirrhosis and age have demonstrated an association;however,the number of studies is very small,and more research is required to investigate risk factors for HCC secondary to HCV genotype-3.

Repetitive transcranial magnetic stimulation enhanced by neuronavigation in the treatment of depressive disorder and schizophrenia

This editorial assesses the advancements in neuronavigation enhanced repetitive transcranial magnetic stimulation for depressive disorder and schizophrenia treatment.Conventional repetitive transcranial magnetic stimulation faces challenges due to the intricacies of brain anatomy and patient variability.Neuronavigation offers innovative solutions by integrating neuroimaging with three-dimensional localization to pinpoint brain regions and refine therapeutic targeting.This systematic review of recent literature underscores the enhanced efficacy of neuronavigation in improving treatment outcomes for these disorders.This editorial highlights the pivotal role of neuronavigation in advancing psychiatric care.

Getting physical with medical education:Exercise based virtual anatomy review classes for medical students

The benefits of regular physical activity are well known.Yet,few studies have examined the effectiveness of integrating physical activity(PA)into curricula within a post-secondary setting.To investigate the incorporation of PA into medical curriculum,we developed a series of optional exercise-based review sessions designed to reinforce musculoskeletal(MSK)anatomy course material.These synchronous sessions were co-taught by a group fitness instructor and an anatomy instructor.The fitness instructor would lead students through both strength and yoga style exercises,while the anatomy instructor asked questions about relevant anatomical structures related to course material previously covered.After the sessions,participants were asked to evaluate the classes on their self-reported exam preparedness in improving MSK anatomy knowledge,PA levels,and mental wellbeing.Thirty participants completed surveys;a majority agreed that the classes increased understanding of MSK concepts(90.0%)and activity levels(97.7%).Many(70.0%)felt that the classes helped reduce stress.The majority of respondents(90.0%)agreed that the classes contributed to increased feelings of social connectedness.Overall,medical students saw benefit in PA based interventions to supplement MSK course concepts.Along with increasing activity levels and promoting health behaviours,integrating PA into medical curriculum may improve comprehension of learning material,alleviate stress and foster social connectivity among medical students.

Development and characterization of 3D-printed electroconductive pHEMA-co-MAA NP-laden hydrogels for tissue engineering

Tissue engineering(TE)continues to be widely explored as a potential solution to meet critical clinical needs for diseased tissue replacement and tissue regeneration.In this study,we developed a poly(2-hydroxyethyl methacrylate-co-methacrylic acid)(pHEMA-co-MAA)based hydrogel loaded with newly synthesized conductive poly(3,4-ethylene-dioxythiophene)(PEDOT)and polypyrrole(PPy)nanoparticles(NPs),and subsequently processed these hydrogels into tissue engineered constructs via three-dimensional(3D)printing.The presence of the NPs was critical as they altered the rheological properties during printing.However,all samples exhibited suitable shear thinning properties,allowing for the development of an optimized processing window for 3D printing.Samples were 3D printed into pre-determined disk-shaped configurations of 2 and 10 mm in height and diameter,respectively.We observed that the NPs disrupted the gel crosslinking efficiencies,leading to shorter degradation times and compressive mechanical properties ranging between 450 and 550 kPa.The conductivity of the printed hydrogels increased along with the NP concentration to(5.10±0.37)×10^(−7)S/cm.In vitro studies with cortical astrocyte cell cultures demonstrated that exposure to the pHEMA-co-MAA NP hydrogels yielded high cellular viability and proliferation rates.Finally,hydrogel antimicrobial studies with staphylococcus epidermidis bacteria revealed that the developed hydrogels affected bacterial growth.Taken together,these materials show promise for various TE strategies.

Ensuring Secure Platooning of Constrained Intelligent and Connected Vehicles Against Byzantine Attacks:A Distributed MPC Framework

This study investigates resilient platoon control for constrained intelligent and connected vehicles(ICVs)against F-local Byzantine attacks.We introduce a resilient distributed model-predictive platooning control framework for such ICVs.This framework seamlessly integrates the predesigned optimal control with distributed model predictive control(DMPC)optimization and introduces a unique distributed attack detector to ensure the reliability of the transmitted information among vehicles.Notably,our strategy uses previously broadcasted information and a specialized convex set,termed the“resilience set”,to identify unreliable data.This approach significantly eases graph robustness prerequisites,requiring only an(F+1)-robust graph,in contrast to the established mean sequence reduced algorithms,which require a minimum(2F+1)-robust graph.Additionally,we introduce a verification algorithm to restore trust in vehicles under minor attacks,further reducing communication network robustness.Our analysis demonstrates the recursive feasibility of the DMPC optimization.Furthermore,the proposed method achieves exceptional control performance by minimizing the discrepancies between the DMPC control inputs and predesigned platoon control inputs,while ensuring constraint compliance and cybersecurity.Simulation results verify the effectiveness of our theoretical findings.

Mapping and Floristic Diversity of the Nakpadjouak Community Forest, Tami Canton, Togo (West Africa)

Since 2015, community forests have been promoted in Togo as an alternative to protect areas from degradation and as a means of contributing to forest landscape restoration. The study focuses on the Nakpadjouak Community Forest (NCF) in Tami (Togo, West Africa) which contributes to community forests sustainable management. It aims in (i) mapping forest ecosystems and analysing their dynamic and (ii) characterizing the floristic diversity of the NCF. The ecosystems were mapped and their dynamic was evaluated based on Google Earth images of 2014 and 2020. Floristic and forestry inventories were carried out using the transect technique in a sample of 20 plots of 50 m × 20 m. The NCF was made up mainly by wooded/shrub savannahs (95.37%) and croplands/fallow (4.63%) in 2014. These two land use types undergone changes over the 6 years prior to 2020. By 2020, the NCF had 3 land use types: wooded/shrub savannahs (77.59%), open forest/wooded savannahs (22.23%), and croplands/fallows (0.18%). A total of 89 plant species belonging to 70 genera and 28 families were recorded within the NCF. The dominant species are: Heteropogon contortus (L.) P.Beauv. and Combretum collinum Fresen. followed by Pteleopsissuberosa Engl. & Diels, Annona senegalensis Pers. The most common species are: Lannea acida A.Rich. s.l., A. senegalensis, Vitellaria paradoxa C.F.Gaertner subsp. paradoxa, C. collinum and Acacia dudgeonii Craib ex Holland. Due to its small area of just 40 hectares and its diverse plant life, this community forest of Savannahs Region is a significant biodiversity hotspot and warrants conservation efforts.

CO_(2) conversion to solar fuels and chemicals:Opening the new paths

This future article discusses the new prospects and directions of CO_(2)conversion via the photo-electrocatalytic(PEC)route.The second(2nd)generation solar fuels and chemicals(SFs)are generated directly in PEC systems via electrons/protons reactions without forming molecular H_(2)as an intermediate,overcoming the thermodynamics limitations and practical issues encountered for electro-fuels produced by multistep thermocatalytic processes(i.e.CO_(2)conversion with H_(2)coming from water electrolysis).A distributed and decentralized production of SFs requires very compact,highly integrated,and intensified technologies.Among the existing reactors of advanced design(based on artificial leaves or photosynthesis),the integrated photovoltaic plus electrocatalytic(PV-EC)device is the only system(demonstrated at large scale)to produce SFs with high solar-to-fuel(STF)efficiency.However,while the literature indicates STF efficiency as the main(and only)measure of process performance,we remark here the need to refer to productivity(in terms of current density)and make tests with reliable flow PEC systems(with electrodes of at least 5–10 cm^(2))to accelerate the scaling-up process.Using approaches that minimize downstream separation costs is also mandatory.Many limitations exist in PEC systems,but most can be overcome by proper electrode and cell engineering,thus going beyond the properties of the electrocatalysts.As examples of current developments,we present the progress of(i)artificial leaf/tree devices for green H_(2)distributed production and(ii)a PEC device producing the same chemicals at both cathode and anode parts without downstream operations for green solvent distributed production.Based on these developments,future directions,such as producing fertilizers and food components from the air,are outlined.The aim is to provide new ideas and research directions from a personal perspective.

Chronic Hepatitis B Virus Infection: Biological Parameters in Patients Treated with Tenofovir Disoproxil Fumarate

Chronic hepatitis B causes a liver disease characterized by inflammation of the liver parenchyma. The aim of this study was to investigate the evolution of biological parameters in patients treated with Tenofovir for chronic B infection at the Commune V referral health center in Bamako. We obtained a prevalence of 14.15%. The most represented age group was 31 - 40 years, with 36.8%. The sex ratio was 1.44 in favour of men. Viral load was undetectable after 18 months of treatment in 25 patients (42.37%). Tenofovir, the 1st-line drug in Mali, is effective on the biological parameters monitored in patients.

De Novo Glomerular Diseases after COVID-19 Vaccination: Consequence or Coincidence?

Introduction: Vaccination against COVID-19 has proven highly effective in preventing severe forms of the disease. However, the literature reports several cases associating renal damage and the anti-COVID vaccine. The aim of our work was to report a case series of patients who developed glomerulopathy after anti-COVID-19 vaccine. We evaluated the type of vaccine, the clinico-biological profile, and the anatomopathological, therapeutic and evolutionary aspects. Material and Methods: Prospective descriptive study conducted at the Nephrology Department of CHU IbnSina in Rabat between December 2021 and June 2022 including 9 patients who presented with glomerulopathy after the 1st dose of anti-COVID-19 vaccine. We excluded patients followed for nephropathy. Results: The mean age of our patients was 33 ± 16 years with a sex ratio of 0.8. Six patients received an inactivated vaccine, 2 patients received a mRNA vaccine and 1 patient received a viral vector vaccine. The mean delay between the onset of signs and the date of the first vaccine dose was 3.1 +/? 0.65 months (1 - 6 months). All patients had a nephrotic syndrome, 2 pure and 7 impure: 3 patients had acute renal failure and microscopic hematuria, 2 patients had microscopic hematuria and 2 patients had acute renal failure. Histologically, focal segmental glomerulosclerosis (FSGS) was noted in 4 patients, lupus nephropathy in 3, and membranous nephropathy (MN) in 2. Specific treatment was administered to each patient, depending on the histological type of renal involvement and the context. After 6 months, complete remission was achieved in 5 patients, with no improvement in 2, and one patient was placed on hemodialysis. One patient died of another cause. Conclusion: The causal link between anti-COVID 19 vaccination and renal disease is highly probable, but remains to be confirmed.

Alteration of chemical behavior of L-ascorbic acid in combination with nickel sulfate at different pH solutions in vitro

Objective:To evaluate the alteration of chemical behavior of L-ascorbic acid(vitamin C) with metal ion(nickel) at different pH solutions in vitro.Methods:Spectra of pure aqueous solution of L-ascorbic acid(E mark) compound and NiSO_4(H_2O)(sigma USA) were evaluated by UV visible spectrophotometer.Spectral analysis of L-ascorbic acid and nickel at various pH(2.0, 7.0,7.4 and 8.6) at room temperature of 29℃ was recorded.In this special analysis,combined solution of L-ascorbic acid and nickel sulfate at different pH was also recorded.Results:The result revealed that λ_(max)(peak wavelength of spectra) of L-ascorbic acid at pH 2.0 was 289.0 run whereas at neutral pH 7.0,λ_(max) was 29S.4 run.In alkaline pH 8.6,λ_(max) was 295.4 nm and at pH 7.4 the λ_(max) of L-ascorbic acid remained the same as 295.4 nm.Nickel solution at acidic pH 2.0 was 394.5 nm,whereas at neutral pH 7.0 and pH 7.4 were the same as 394.5 nm.But at alkaline pH 8.6,λ_(max) value of nickel sulfate became 392.0 nm.The combined solution of L-ascorbic acid and nickel sulfate(6 mg/mL each) at pH 2.0 showed 292.5 nm and 392.5 nm,respectively whereas at pH 7.0,L-ascorbic acid showed 296.5 nm and nickel sulfate showed 391.5 nm.At pH 7.4,L-ascorbic acid showed 297.0 nm and nickel sulfate showed 394.0 nm in the combined solution whereas at pH 8.6(alkaline) L-ascorbic acid and nickel sulfate were showing 297.0 and 393.5 nm,respectively. Conclusions:Results clearly indicate an altered chemical behavior of L-ascorbic acid either alone or in combination with nickel sulfate in vitro at different pH.Perhaps oxidation of L-ascorbic acid to L-dehydro ascorbic acid via the free radical(HSc*) generation from the reaction of H,ASc + Ni(Ⅱ) is the cause of such alteration of λ_(max),value of L-ascorbic acid in the presence of metal nickel.

Liquid injectivity in a SAG foam process:Effect of permeability

Foam is utilized in enhanced oil recovery and CO_(2) sequestration.Surfactant-alternating-gas(SAG)is a preferred approach for placing foam into reservoirs,due to it enhances gas injection and minimizes corrosion in facilities.Our previous studies with similar permeability cores show that during SAG injection,several banks occupy the area near the well where fluid exhibits distinct behaviour.However,underground reservoirs are heterogeneous,often layered.It is crucial to understand the effect of permeability on fluid behaviour and injectivity in a SAG process.In this work,coreflood experiments are conducted in cores with permeabilities ranging from 16 to 2300 mD.We observe the same sequence of banks in cores with different permeabilities.However,the speed at which banks propagate and their overall mobility can vary depending on permeability.At higher permeabilities,the gas-dissolution bank and the forced-imbibition bank progress more rapidly during liquid injection.The total mobilities of both banks decrease with permeability.By utilizing a bank-propagation model,we scale up our experimental findings and compare them to results obtained using the Peaceman equation.Our findings reveal that the liquid injectivity in a SAG foam process is misestimated by conventional simulators based on the Peaceman equation.The lower the formation permeability,the greater the error.

Enhancing XRF sensor-based sorting of porphyritic copper ore using particle swarm optimization-support vector machine(PSO-SVM)algorithm

X-ray fluorescence(XRF)sensor-based ore sorting enables efficient beneficiation of heterogeneous ores,while intraparticle heterogeneity can cause significant grade detection errors,leading to misclassifications and hindering widespread technology adoption.Accurate classification models are crucial to determine if actual grade exceeds the sorting threshold using localized XRF signals.Previous studies mainly used linear regression(LR)algorithms including simple linear regression(SLR),multivariable linear regression(MLR),and multivariable linear regression with interaction(MLRI)but often fell short attaining satisfactory results.This study employed the particle swarm optimization support vector machine(PSO-SVM)algorithm for sorting porphyritic copper ore pebble.Lab-scale results showed PSO-SVM out-performed LR and raw data(RD)models and the significant interaction effects among input features was observed.Despite poor input data quality,PSO-SVM demonstrated exceptional capabilities.Lab-scale sorting achieved 93.0%accuracy,0.24%grade increase,84.94%recovery rate,57.02%discard rate,and a remarkable 39.62 yuan/t net smelter return(NSR)increase compared to no sorting.These improvements were achieved by the PSO-SVM model with optimized input combinations and highest data quality(T=10,T is XRF testing times).The unsuitability of LR methods for XRF sensor-based sorting of investigated sample is illustrated.Input element selection and mineral association analysis elucidate element importance and influence mechanisms.