A Comprehensive Evaluation of Dioxins and Furans Occurrence in River Sediments from a Secondary Steel Recycling Craft Village in Northern Vietnam.

This first study investigated the presence of dioxins and furans in river sediments around a craft village in Vietnam, focusing on Secondary Steel Recycling. Sediment samples were collected from various locations along the riverbed near the Da Hoi Secondary Steel Recycling village in Bac Ninh province. The analysis was conducted using a HRGC/HRMS-DFS device, detecting a total of 17 dioxin/furan isomers in all samples, with an average total concentration of 288.86 ng/kg d.w. The concentrations of dioxin/furan congeners showed minimal variation among sediment samples, ranging from 253.9 to 344.2 ng/kg d.w. The predominant compounds in the dioxin group were OCDD, while in the furan group, they were 1,2,3,4,6,7,8-HpCDF and OCDF. The chlorine content in the molecule appeared to be closely related to the concentration of dioxins and their percentage distribution. However, the levels of furan isomers did not vary significantly. The distribution of these compounds was not dependent on the flow direction, as they were mainly found in solid waste and are not water-soluble. Although the hepta and octa congeners had high concentrations, when converted to TEQ values, the tetra and penta groups (for dioxins) and the penta and hexa groups (for furans) contributed more to toxicity. Furthermore, the source of dioxins in sediments at Da Hoi does not only originate from steel recycling production activities but also from other combustion sites. The average total toxicity was 10.92 ng TEQ/kg d.w, ranging from 4.99 to 17.88 ng TEQ/kg d.w, which did not exceed the threshold specified in QCVN 43:2017/BTNMT, the National Technical Regulation on Sediment Quality. Nonetheless, these levels are still concerning. The presence of these toxic substances not only impacts aquatic organisms in the sampled water environment but also poses potential health risks to residents living nearby.

Endovascular treatment for acute ischemic stroke beyond the 24-h time window: Selection by target mismatch profile.

INTRODUCTION: Endovascular treatment for acute ischemic stroke patients with large vessel occlusion (LVO) has been established as a promising clinical intervention within a late time window of 6-24 h after symptom onset. Patients with slow progression, however, may still benefit from endovascular treatment beyond the 24-h time window (very late window). AIM: The aim of this study is to report insight into the potential clinical benefits of endovascular treatment for acute ischemic stroke beyond 24 h from symptom onset. METHODS: A retrospective analysis was performed on consecutive patients undergoing endovascular treatment for acute anterior circulation LVO ischemic stroke beyond 24 h. Participants were recruited between July 2019 and November 2020. Patients were selected based on the DAWN/DEFUSE 3 criteria (Perfusion-RAPID, iSchemaView) and patients receiving treatment beyond 24 h were compared to a group of patients receiving endovascular treatment between 6 and 24 h after symptom onset. The primary outcome was the proportion of patients with functional independence at 90 days (modified Rankin Scale score of 0-2). The secondary outcomes were shift modified Rankin Scale (mRS) analysis and successful reperfusion was defined by thrombolysis in cerebral infarction (TICI) 2b-3 on the final procedure. Safety outcomes were symptomatic intracranial hemorrhage and death at the 90-day follow-up. Propensity score (PS)-matched analyses were employed to rectify the imbalanced baseline characteristics between the two groups. RESULTS: A total of 166 patients were recruited with a median age of 63.0 (56.0-69.0) and 28.9% of all patients were females. Patients in the beyond 24-h group had a longer onset-to-groin time (median = 27.2 vs 14.3 h, p < 0.001) than those in the 6- to 24-h group. There were no statistically significant differences between the two groups in National Institutes of Health Stroke Scale (NIHSS) (median = 12.0 vs 15.0, p = 0.37), perfusion imaging characteristics (core: median = 11.0 vs 9.0 mL, p = 0.86; mismatch volume: median = 106.0 vs 96.0, p = 0.44; mismatch ratio = 6.46 vs 7.24, p = 0.91), and perfusion-to-groin time (median = 72.5 vs 76.0 min, p = 0.77). No significant differences were noted among patients between the two groups in the primary endpoint functional independence analysis (50.0% vs 46.6%, p = 0.77) and in the safety endpoint analysis: mortality (15.0% vs 11.0%, p = 0.71) or symptomatic hemorrhage (0% vs 3.42%, p > 0.999). In PS-matched analyses, there were no significant differences among patients between the two groups in functional independence (50.0% vs 54.8%, p = 0.74), mortality (16.7% vs 9.68%, p = 0.50), or symptomatic hemorrhage (0% vs 6.45%, p = 0.53). CONCLUSION: Endovascular treatment can be performed safely and effectively in LVO patients beyond 24 h from symptom onset when selected by target mismatch profile. The clinical outcome of these patients was comparable to those treated in the 6- to 24-h window. Larger studies are needed to confirm these findings.

Surveillance for liver cancer in primary care: A systematic review of the evidence.

BACKGROUND AND OBJECTIVES: In Australia, mortality rates for hepatocellular carcinoma (HCC) are rising. Targeted surveillance is recommended to increase early diagnosis. The aim of this study was to synthesise evidence regarding HCC surveillance in primary care and identify barriers and facilitators to surveillance. METHOD: A systematic review was performed, with searches conducted in five biomedical databases, the Centre for Reviews and Dissemination website and the grey literature. Study quality was assessed using the National Institute for Heath and Care Excellence (NICE) quality appraisal checklists. RESULTS: In all, 32 studies, focusing on viral hepatitis and cirrhosis patients, were included in the review. HCC surveillance rates were lower for patients managed by primary care providers (PCPs) than for those managed by gastroenterologists/hepatologists. HCC surveillance rates increased when additional support was provided to PCPs (eg reminder systems, nurse follow-up). Key barriers were a lack of awareness of HCC risks and surveillance recommendations, as well as competing priorities PCPs must address when working with patients with multimorbidity. DISCUSSION: HCC surveillance programs in primary care should be accompanied by additional support for PCPs and strategies to increase awareness of clinical recommendations.

Undescribed 2,9-deoxyflavonoids and flavonol-diamide [3+2] adduct from the leaves of Aglaia odorata Lour. Inhibit nitric oxide production.

Phytochemical study on the methanol extract of Aglaia odorata leaves resulted in the isolation of four previously undescribed compounds, including three 2,9-deoxyflavonoids and one flavonol-diamide [3 + 2] adduct, and 13 known compounds. The chemical structures of the four undescribed compounds were elucidated on the basis of their IR, HR-ESI-MS, 1D and 2D NMR, and ECD spectra. The results revealed an unprecedented 2,9-deoxyflavonoid framework, which was confirmed by TD-DFT, ECD, and GIAO 13C-NMR calculations using sorted training set methods. The 17 compounds were examined for their ability to inhibit NO production activity in cultured lipopolysaccharide-activated RAW264.7 cells with aglaodoratas A-C, odorine, and epi-odorine inhibiting NO production, with IC50 values in the range of 16.2-24.3 µM. The other investigated compounds had either weak or no activity.

Factors Affecting the Adsorption of Per- and Polyfluoroalkyl Substances (PFAS) by Colloidal Activated Carbon.

The immobilization of per- and polyfluoroalkyl substances (PFAS) by colloidal activated carbon (CAC) barriers has been proposed as a potential in-situ method to mitigate the transport of plumes of PFAS in the subsurface. However, if PFAS are continuously released from a source zone, the adsorptive sites on CAC will eventually become saturated, upon which point the breakthrough of PFAS in the barrier will occur. To predict the long-term effectiveness of CAC barriers, it is important to evaluate the factors that may affect the adsorption of PFAS on CAC. In this study, the adsorption of 7 PFAS on a polymer-stabilized CAC (i.e., PlumeStop®) and on a polymer-free CAC was investigated using batch experiments. The adsorption affinity of PFAS to CAC was in the following order: PFOS > 6:2 FTS > PFHxS > PFOA > PFBS > PFPeA > PFBA. This result indicates that hydrophobic interaction was the predominant adsorption mechanism, and that hydrophilic compounds such as PFBA and PFPeA will break through CAC barriers first. The partition coefficient Kd for the adsorption of PFAS on the polymer-stabilized CAC was 1.3 - 3.5 times smaller than the Kd for the adsorption of PFAS on the polymer-free CAC, suggesting that the polymers decreased the adsorption, presumably due to competitive sorption. Thus, the PFAS adsorption capacity of PlumeStop CAC barriers is expected to increase once the polymers are biodegraded and/or washed away. The affinity of PFOS and PFOA to CAC increased when the ionic strength of the solution increased from 1 to 100 mM, or when the concentration of Ca2+ increased from 0 to 2 mM. In contrast, less PFOS and PFOA were adsorbed in the presence of 1 - 20 mgC/L Suwannee River Fulvic Acid, which represented dissolved organic carbon, or in the presence of 10 - 100 mg/L diethylene glycol butyl ether (DGBE), which is an important component in some aqueous film-forming foam (AFFF) formulations. The presence of 0.5 - 4.8 mg/L benzene or 0.5 - 8 mg/L trichloroethylene, the co-contaminants that may comingle with PFAS at AFFF-impacted sites, diminished PFOS adsorption but had no effect or even slightly enhanced PFOA adsorption. When the initial concentration of TCE was 8 mg/L, the Kd (514 ± 240 L/g) for the adsorption of PFOS was approximately 20 times lower than that in the TCE-free system (Kd = 9,579 ± 829 L/g). The results of this study provided insights into some key factors that may affect the adsorption of PFAS in in-situ CAC barriers.

New nitric oxide production inhibitors from Syzygium bullockii.

Three undescribed triterpene glycosides syzybullosides A-C (1-3) along with fourteen known compounds were isolated from the leaves of Syzygium bullockii (Hance) Merr.& L.M. Perry, including six triterpene glycosides (1-6), four phenolics (7-9, 17), four megastigmanes (10-13), and three flavonoids (14-16). The structures of 1-17 were elucidated by extensive spectroscopic analysis, including IR, HR-ESI-MS, 1D and 2D NMR spectra. Compounds 1-10 and 12-17 inhibited nitric oxide (NO) production in lipopolysaccharide activated RAW264.7 cells with IC50 values ranging from 1.30 to 13.70 µM, lower than that of the positive control compound, L-NMMA (IC50 = 33.8 µM).

A field-validated equilibrium passive sampler for the monitoring of per- and polyfluoroalkyl substances (PFAS) in sediment pore water and surface water.

A simple equilibrium passive sampler, consisting of water in an inert container capped with a rate-limiting barrier, for the monitoring of per- and polyfluoroalkyl substances (PFAS) in sediment pore water and surface water was developed and tested through a series of laboratory and field experiments. The objectives of the laboratory experiments were to determine (1) the membrane type that could serve as the sampler's rate-limiting barrier, (2) the mass transfer coefficient of environmentally relevant PFAS through the selected membrane, and (3) the performance reference compounds (PRCs) that could be used to infer the kinetics of PFAS diffusing into the sampler. Of the membranes tested, the polycarbonate (PC) membrane was deemed the most suitable rate-limiting barrier, given that it did not appreciably adsorb the studied PFAS (which have ≤8 carbons), and that the migration of these compounds through this membrane could be described by Fick's law of diffusion. When employed as the PRC, the isotopically labelled PFAS M2PFOA and M4PFOS were able to predict the mass transfer coefficients of the studied PFAS analytes. In contrast, the mass transfer coefficients were underpredicted by Br- and M3PFPeA. For validation, the PC-based passive samplers consisting of these four PRCs, as well as two other PRCs (i.e., M8PFOA and C8H17SO3-), were deployed in the sediment and water at a PFAS-impacted field site. The concentration-time profiles of the PRCs indicated that the samplers deployed in the sediment required at least 6 to 7 weeks to reach 90% equilibrium. If the deployment times are shorter (e.g., 2 to 4 weeks), PFAS concentrations at equilibrium could be estimated based on the concentrations of the PRCs remaining in the sampler at retrieval. All PFAS concentrations determined via this approach were within a factor of two compared to those measured in the mechanically extracted sediment pore water and surface water samples obtained adjacent to the sampler deployment locations. Neither biofouling of the rate-limiting barrier nor any physical change to it was observed on the sampler after retrieval. The passive sampler developed in this study could be a promising tool for the monitoring of PFAS in pore water and surface water.

Hepatocellular carcinoma surveillance based on the Australian Consensus Guidelines: a health economic modelling study.

BACKGROUND: Hepatocellular carcinoma (HCC) is the fastest increasing cause of cancer death in Australia. A recent Australian consensus guidelines recommended HCC surveillance for cirrhotic patients and non-cirrhotic chronic hepatitis B (CHB) patients at gender and age specific cut-offs. A cost-effectiveness model was then developed to assess surveillance strategies in Australia. METHODS: A microsimulation model was used to evaluate three strategies: biannual ultrasound, biannual ultrasound with alpha-fetoprotein (AFP) and no formal surveillance for patients having one of the conditions: non-cirrhotic CHB, compensated cirrhosis or decompensated cirrhosis. One-way and probabilistic sensitivity analyses as well as scenario and threshold analyses were conducted to account for uncertainties: including exclusive surveillance of CHB, compensated cirrhosis or decompensated cirrhosis populations; impact of obesity on ultrasound sensitivity; real-world adherence rate; and different cohort's ranges of ages. RESULTS: Sixty HCC surveillance scenarios were considered for the baseline population. The ultrasound + AFP strategy was the most cost-effective with incremental cost-effectiveness ratios (ICER) compared to no surveillance falling below the willingness-to-pay threshold of A$50,000 per quality-adjusted life year (QALY) at all age ranges. Ultrasound alone was also cost-effective, but the strategy was dominated by ultrasound + AFP. Surveillance was cost-effective in the compensated and decompensated cirrhosis populations alone (ICERs < $30,000), but not cost-effective in the CHB population (ICERs > $100,000). Obesity could decrease the diagnostic performance of ultrasound, which in turn, reduce the cost-effectiveness of ultrasound ± AFP, but the strategies remained cost-effective. CONCLUSIONS: HCC surveillance based on Australian recommendations using biannual ultrasound ± AFP was cost-effective.

Prospective, open-label, and observational study of cetuximab for metastatic colorectal carcinoma: The OPTIM1SE study.

AIM: The OPTIM1SE study observed long-term real-world outcomes of cetuximab-based infusional 5-fluorouracil (5-FU) regimens for first-line treatment of metastatic colorectal cancer (mCRC) across Asia-Pacific and Middle East regions, aiming to characterize their use, effectiveness, and safety in routine practice. METHODS: OPTIM1SE was a prospective, open-label, observational study. Patients with untreated KRAS wild-type mCRC and distant metastases were treated per locally approved labels and monitored for 3 years via electronic medical records. The primary endpoint was the overall response rate (ORR). Secondary endpoints included safety, progression-free survival (PFS), and overall survival (OS). RESULTS: From November 19, 2013, to June 30, 2016, 520 patients were enrolled in 51 sites. Patients were mostly male (61.2%), with a mean age of 58.5 (±12.0) years; 420 patients received leucovorin, 5-FU, and irinotecan-based regimens and 94 received leucovorin, 5-FU, and oxaliplatin. The most common primary tumor site was the rectum (38.8%), with liver metastases (65.0%). ORR was 45.4% (95% CI, 41.1%-49.7%), including 26 patients (5.0%) with a complete response. Median PFS was 9.9 months (95% CI, 8.2-11.0); median OS (mOS) was 30.8 months (95% CI, 27.9-33.6). Higher mOS was associated with tumors of left compared with right-sided origin (hazard ratio, 0.69 [95% CI, 0.49-0.99]); higher ORR was also associated with liver metastases compared with all other metastases (55.4% vs. 40.2%). Adverse events were consistent with the known safety profile of cetuximab. CONCLUSION: Cetuximab-based 5-FU regimens were effective first-line treatments for mCRC in routine practice, particularly in patients with left-sided disease and liver metastases only.

Isolation, structural elucidation and molecular docking studies against SARS-CoV-2 main protease of new stigmastane-type steroidal glucosides isolated from the whole plants of Vernonia gratiosa.

Phytochemical investigation of the whole plants of Vernonia gratiosa Hance. led in the isolation and identification of two new stigmastane-type steroidal glucosides (1-2), namely vernogratiosides A (1), and B (2). Their chemical structures were fully elucidated based on 1 D/2D NMR spectroscopic, HR-ESI-MS data analyses, and by producing derivatives by chemical reactions. The binding potential of the isolated compounds to replicase protein - main protease of SARS-CoV-2 were examined using the molecular docking simulations. Our results show that the isolated steroidal glucosides (1-2) bind to the substrate-binding site of SARS-CoV-2 main protease with binding affinities of -7.2 and -7.6 kcal/mol, respectively, as well as binding abilities equivalent to N3 inhibitor that has already been reported (-7.5 kcal/mol).

Survival of primary liver cancer for people from culturally and linguistically diverse backgrounds in Australia.

BACKGROUND: Survival for Primary Liver Cancer (PLC) has been investigated in Australia, but limited work has been conducted on the burden for people with different socioeconomic status, region of residence, causes of PLC, and culturally and linguistically diverse (CALD) backgrounds. This study aimed to cover this gap in the literature by investigating PLC survival with the aforementioned factors. METHODS: This study linked four administrative datasets: Victorian Cancer Registry, Admitted Episodes Dataset, Emergency Minimum Dataset, and Death Index. The cohort was all cases with a PLC notification within the Victorian Cancer Registry between 01/01/2008 and 01/01/2016. The Kaplan-Meier method was used to estimate survival probabilities and the log-rank test was used to compare the difference in survival between subgroups. The Cox proportional hazard model was used to explore factors associated with PLC survival. RESULTS: The 1-, 3- and 5-year survival rates were 50.0%, 28.1% and 20.6%, respectively, with a median survival of 12.0 months (95% confidence interval (CI): 11.0 - 12.9 months). Higher survival was associated with younger age, hepatocellular carcinoma, and higher socio-economic status. People born in Asian, African, and American regions had higher survival than those born in Australia and New Zealand. Cases with viral hepatitis as an identified aetiology had higher survival than those whose PLC was related to alcohol consumption (hazard ratio=1.52, 95% CI: 1.19 - 1.96), diabetes and fatty liver disease (hazard ratio=1.35, 95% CI: 1.08 - 1.68). CONCLUSION: Survival outcomes for people diagnosed with PLC were still poor and affected by many factors. Asian and African cases had better survival than Australian and New Zealand patients as PLC in Asian and African cases was mostly caused by viral hepatitis. Metropolitan areas were associated with a higher survival than rural areas, not only due to accessibility to surveillance and healthcare services but also because the majority of overseas-born patients reside in metropolitan areas.

Hospitalisation costs of primary liver cancer in Australia: evidence from a data-linkage study.

Objective This study aimed to estimate the public hospital costs associated with primary liver cancer (PLC) in the first and second years following the cancer diagnosis. Methods This study linked administrative datasets of patients diagnosed with PLC in Victoria, Australia, from January 2008 to December 2015. The health system perspective was adopted to estimate the direct healthcare costs associated with PLC, based on inpatient and emergency costs. Costs were estimated for the first 12 months and 12-24 months after the PLC diagnosis and expressed in 2017 Australian dollars (A$). The cost estimated was then extrapolated nationally. The linear mixed model with a Box-Cox transformation of the costs was used to explore the relationship between costs and patients' sociodemographic and clinical characteristics. Results For the first 12 months, the total and annual per-patient cost was A$211.4 million and A$63 664, respectively. Costs for the subsequent year were A$49.7 million and A$46 751, respectively. Regarding the cost extrapolation to Australia, the total cost was A$137 million for the first 12 months after notification and A$42.6 million for the period from 12 to 24 months. Higher costs per episode of care were mostly associated with older age, hepatocellular carcinoma type of PLC, metropolitan hospitals, and Asian birth region. Conclusion This study showed the public hospital admission and emergency costs associated with PLC and the substantial economic burden this cancer has placed on the Australian health system.

Chemical constituents and absolute configuration of megastigmanes' isolated from Sedum sarmentosum Bunge.

Phytochemical investigation of a methanolic extract of Sedum sarmentosum collected from Vietnam resulted in the isolation of a new megastigmane glucoside, named sedumoside K (1), together with 17 previously reported compounds (2-18). Structural elucidation of the new compound was achieved by HRFABMS, NMR spectroscopic analysis, acid hydrolysis and quantum ECD calculations. The absolute configuration of compounds 2-6 has been revised. The major isolates were tested for cytotoxic activity against HeLa human cervical cancer cells, and all showed moderate activities.

A new steroidal saponin from the aerial parts of Solanum torvum.

A new steroidal saponin, torvoside R (1), was isolated along with torvoside Q (2) and macaoside (3) from dichloromethane soluble-portion of the aerial parts of Solanum torvum. Their chemical structures were elucidated using HRESIMS, 1 D- and 2 D-NMR as well as comparison with those reported in the literature. All isolated compounds (1 - 3) exhibited cytotoxicity against SK-LU-1, HepG2, MCF-7, and T24 cancer cell lines with IC50 values ranging from 14.18 to 89.31 µg/mL.

Assessment of arsenic contamination of milk and dairy products / Evaluación de la contaminación por arsénico de la leche y productos lácteos

ABSTRACTS Introduction: Milk and dairy products are nutritious and can play a significant role in a healthy diet. The safety of milk decreases with increasing concentration of arsenic. The Maximum Residue Limits of arsenic is 500 parts per billion (ppb). Objectives: To evaluate the status of arsenic contamination of milk and dairy products produced and processed in some provinces and cities of Vietnam. Methods: A total of 367 samples were tested. Samples were digested before analysis to remove organic compounds, and the total arsenic content determined by atomic absorption spectrophotometry. Results: The average concentrations of total arsenic in liquid milk were 139.32 ppb; in yogurt, 169.81 ppb; in cheese, 221.38 ppb; in milk cake, 232.80 ppb; and in milk powder, 35.43 ppb, respectively. Conclusion: The arsenic concentrations in some samples are higher than the maximum permitted levels according to national regulations.

RESUMEN Introducción: La leche y los productos lácteos son nutritivos y pueden desempeñar un papel importante en una dieta saludable. La seguridad de la leche disminuye con el aumento de la concentración de arsénico. Los límites máximos de residuos de arsénico son 500 ppb. Objetivos: Evaluar el estado de contaminación por arsénico de la leche y los productos lácteos producidos y procesados ​​en algunas provincias y ciudades de Vietnam. Métodos: Se analizaron un total de 367 muestras. Las muestras se digirieron antes del análisis, para eliminar los compuestos orgánicos y se determinó el contenido total de arsénico mediante espectrofotometría de absorción atómica. Resultados: Las concentraciones promedio de arsénico total en la leche líquida fueron 139,32 ppb; en el yogur, 169,81 ppb; en el queso, 221,38 ppb; en el pastel de leche, 232,80 ppb; y en la leche en polvo, 35,43 ppb, respectivamente. Conclusión: Las concentraciones de arsénico en algunas muestras superan los niveles máximos permitidos según la normativa nacional.

Pharmacological Properties, Volatile Organic Compounds, and Genome Sequences of Bacterial Endophytes from the Mangrove Plant Rhizophora apiculata Blume.

Mangrove plant endophytic bacteria are prolific sources of bioactive secondary metabolites. In the present study, twenty-three endophytic bacteria were isolated from the fresh roots of the mangrove plant Rhizophora apiculata. The identification of isolates by 16S rRNA gene sequences revealed that the isolated endophytic bacteria belonged to nine genera, including Streptomyces, Bacillus, Pseudovibrio, Microbacterium, Brevibacterium, Microbulbifer, Micrococcus, Rossellomorea, and Paracoccus. The ethyl acetate extracts of the endophytic bacteria's pharmacological properties were evaluated in vitro, including antimicrobial, antioxidant, α-amylase and α-glucosidase inhibitory, xanthine oxidase inhibitory, and cytotoxic activities. Gas chromatography-mass spectrometry (GC-MS) analyses of three high bioactive strains Bacillus sp. RAR_GA_16, Rossellomorea vietnamensis RAR_WA_32, and Bacillus sp. RAR_M1_44 identified major volatile organic compounds (VOCs) in their ethyl acetate extracts. Genome analyses identified biosynthesis gene clusters (BGCs) of secondary metabolites of the bacterial endophytes. The obtained results reveal that the endophytic bacteria from R. apiculata may be a potential source of pharmacological secondary metabolites, and further investigations of the high bioactive strains-such as fermentation and isolation of pure bioactive compounds, and heterologous expression of novel BGCs in appropriate expression hosts-may allow exploring and exploiting the promising bioactive compounds for future drug development.

How does periodic polarity reversal affect the faradaic efficiency and electrode fouling during iron electrocoagulation?

Electrocoagulation (EC) is a promising electrochemical water treatment technology. However, a major challenge to sustaining effective long-term EC operation is controlling the precipitation of materials on the electrodes, commonly referred to as fouling. Periodically reversing electrode polarity has been suggested as an in-situ fouling mitigation strategy and is often implemented in EC field applications. However, the utility of this approach has not been investigated in detail. In this study, the effect of polarity reversal (PR) on the performance of EC using iron electrodes was examined under different water chemistry conditions and at a range of reversal frequencies. It was observed that the faradaic efficiency in PR-EC was always lower than that in the EC systems operated with a direct current (i.e., DC-EC). It was also observed that the faradaic efficiency progressively decreased as the current reversal frequency increased, with the faradaic efficiency dropping as low as 10% when the PR interval was 0.5 min. Results from fouling layer, chronopotentiometric, and cyclic voltammetric investigations indicated that the decrease in the faradaic efficiency was caused by (i) increased electrode fouling by iron precipitates and (ii) electrochemical side reactions at the electrode-electrolyte interface. The extent of these effects was dependent on the solution chemistry; oxyanions and sulfide were found to be particularly detrimental to the performance of PR-EC, causing severe electrode fouling while decreasing the faradaic efficiency. Fouling could be mitigated by increasing the solution convection rate, resulting in a shear on the electrode surface that removed iron and other electrochemically reactive species from the electrodes.

A Systematic Review and Narrative Synthesis of Health Economic Evaluations of Hepatocellular Carcinoma Screening Strategies.

OBJECTIVES: Many economic evaluations of hepatocellular carcinoma (HCC) screenings have been conducted; however, these vary substantially with regards to screening strategies, patient group, and setting. This review aims to report the current knowledge of the cost-effectiveness of screening and describe the published data. METHODS: We conducted a search of biomedical and health economic databases up to July 2020. We included full and partial health economic studies if they evaluated the costs or outcomes of HCC screening strategies. RESULTS: The review included 43 studies. Due to significant heterogeneity in key aspects across the studies, a narrative synthesis was conducted. Most studies reported using ultrasound or alpha fetoprotein as screening strategies. Screening intervals were mostly annual or biannual. Incidence, diagnostic performance, and health state utility values were the most critical parameters affecting the cost-effectiveness of screening. The majority of studies reported HCC screening to be cost-effective, with the biannual ultrasound + alpha fetoprotein standing out as the most cost-effective strategy. However, few studies considered the utilization rate, and none considered the diagnostic performance of ultrasound in the context of central adiposity. Computed tomography and magnetic resonance imaging were also evaluated, but its cost-effectiveness was still controversial. CONCLUSIONS: Although many studies suggested HCC screening was cost-effective, substantial limitations of the quality of these studies means the results should be interpreted with caution. Future modeling studies should consider the impact of central adiposity on the precision of ultrasound, real-world utilization rates and projections of increased HCC incidence.

Mitigating Electrode Fouling in Electrocoagulation by Means of Polarity Reversal: The Effects of Electrode Type, Current Density, and Polarity Reversal Frequency.

One of the biggest issues in electrocoagulation (EC) water treatment processes is electrode fouling, which can cause decreased coagulant production, increased ohmic resistance and energy consumption, and reduced contaminant removal efficiency, among other operational problems. While it has been suggested that switching the current direction intermittently (i.e., polarity reversal, PR) can help mitigate electrode fouling, conflicting results about the utility of this approach have been reported in the literature. The objective of this study was to systematically investigate the effects of PR frequency and current density on the performance of Fe-EC and Al-EC. It was found that operating Fe-EC under the PR mode reduced neither electrode fouling nor energy consumption. Notably, the Faradaic efficiency (ϕ) in Fe-EC decreased with increasing PR frequency; ϕ was as low as 10% when a PR frequency of 0.5 minutes was employed. Unlike Fe-EC, operating Al-EC under the PR mode resulted in high coagulant production efficiencies, reduced energy consumption, and diminished electrode fouling. In addition to comparing PR-EC and DC-EC, a novel strategy to minimize electrode fouling was investigated. This strategy involved operating Fe DC-EC and Al DC-EC with a Ti-IrO2 cathode, whose fouling by Ca- and Mg-containing minerals could be readily avoided by periodically switching the current direction.

Treatment of electrochemical plating wastewater by heterogeneous photocatalysis: the simultaneous removal of 6:2 fluorotelomer sulfonate and hexavalent chromium.

6:2 fluorotelomer sulfonate (6:2 FtS) is being widely used as a mist suppressant in the chromate (Cr(vi)) plating process. As a result, it is often present alongside Cr(vi) in the chromate plating wastewater (CPW). While the removal of Cr(vi) from CPW has been studied for decades, little attention has been paid to the treatment of 6:2 FtS. In this study, the removal of Cr(vi) and 6:2 FtS by Ga2O3, In2O3, and TiO2 photocatalysts was investigated. In the Ga2O3/UVC system, over 95% of Cr(vi) was reduced into Cr(iii) after only 5 min. Simultaneously, 6:2 FtS was degraded into F- and several perfluorocarboxylates. The predominant reactive species responsible for the degradation of 6:2 FtS in the Ga2O3 system were identified to be hVB + and O2˙-. In addition, it was observed that the presence of Cr(vi) helped accelerate the degradation of 6:2 FtS. This synergy between Cr(vi) and 6:2 FtS was attributable to the scavenging of eCB - by Cr(vi), which retarded the recombination of eCB - and hVB +. The In2O3/UVC system was also capable of removing Cr(vi) and 6:2 FtS, although at significantly slower rates. In contrast, poor removal of 6:2 FtS was achieved with the TiO2/UVC system, because Cr(iii) adsorbed on TiO2 and inhibited its reactivity. Based on the results of this study, it is proposed that CPW can be treated by a treatment train that consists of an oxidation-reduction step driven by Ga2O3/UVC, followed by a neutralization step that converts dissolved Cr(iii) into Cr(OH)3(S).