Application of electron beam technology to decompose per- and polyfluoroalkyl substances in water

The widespread detection of per- and polyfluoroalkyl substances (PFAS) in environmental compartments across the globe has raised several health concerns. Destructive technologies that aim to transform these recalcitrant PFAS into less toxic, more manageable products, are gaining impetus to address this problem. In this study, a 9 MeV electron beam accelerator was utilized to treat a suite of PFAS (perfluoroalkyl carboxylates: PFCAs, perfluoroalkyl sulfonates, and 6:2 fluorotelomer sulfonate: FTS) at environmentally relevant levels in water under different operating and water quality conditions. Although perfluorooctanoic acid and perfluorooctane sulfonic acid showed >90% degradation at <500 kGy dose at optimized conditions, a fluoride mass balance revealed that complete defluorination occurred only at/or near 1000 kGy. Non-target and suspect screening revealed additional degradation pathways differing from previously reported mechanisms. Treatment of PFAS mixtures in deionized water and groundwater matrices showed that FTS was preferentially degraded (∼90%), followed by partial degradation of long-chain PFAS (∼15-60%) and a simultaneous increase of short-chain PFAS (up to 20%) with increasing doses. The increase was much higher (up to 3.5X) in groundwaters compared to deionized water due to the presence of PFAS precursors as confirmed by total oxidizable precursor (TOP) assay. TOP assay of e-beam treated samples did not show any increase in PFCAs, confirming that e-beam was effective in also degrading precursors. This study provides an improved understanding of the mechanism of PFAS degradation and revealed that short-chain PFAS are more resistant to defluorination and their levels and regulation in the environment will determine the operating conditions of e-beam and other PFAS treatment technologies.

Ameliorating effect of 2'-Fucosyllactose and 6'-Sialyllactose on lipopolysaccharide-induced intestinal inflammation

Human milk oligosaccharides (HMO) affect gut microbiota during neonatal development, particularly with respect to the immune system. Bovine milk-based infant formulas have low oligosaccharide contents. Thus, efforts to fortify infant formulas with HMO are being undertaken. Two major HMO, 2'-fucosyllactose (2'-FL) and 6'-sialyllactose (6'-SL), exert anti-inflammatory effects; however, the associations between anti-inflammatory effects induced by 2'-FL and 6'-SL co-treatment and gut microbiota composition and metabolite modulation remain unclear. Therefore, in this study, we evaluated the effects of a mixture of these HMO. To determine the optimal HMO ratio for anti-inflammatory effects and elucidate its mode of action, LPS-induced inflammatory HT-29 epithelial cells and intestinal inflamed suckling mice were treated with various mixtures of 2'-FL and 6'-SL. 2'-FL:6'-SL ratio of 5:1 was identified as the most effective pre-treatment HMO mixture in vitro; thus, this ratio was selected and used for low, middle, and high-dose treatments for subsequent in vivo studies. In vivo, high-dose HMO treatment restored LPS-induced inflammation symptoms, such as body weight loss, colon length reduction, histological structural damage, and intestinal gene expression related to inflammatory responses. High-dose HMO was the only treatment that modulated the major phyla Bacteroidetes and Firmicutes and the genera Ihubacter, Mageeibacillus, and Saccharofermentans. These changes in microbial composition were correlated with intestinal inflammation-related gene expression and short-chain fatty acid production. To our knowledge, our study is the first to report the effects of Ihubacter, Mageeibacillus, and Saccharofermentans on short chain fatty acid levels, which can subsequently affect inflammatory cytokine and tight junction protein levels. Conclusively, the HMO mixture exerted anti-inflammatory effects through changes in microbiota and metabolite production. These findings suggested that supplementation of infant formula with HMO may benefit formula-fed infants by forming unique microbiota contributing to neonatal development.

Perioperative outcomes of laparoscopic low anterior resection using ArtiSential® versus robotic approach in patients with rectal cancer: a propensity score matching analysis

BACKGROUND

Total mesorectal excision using conventional straight fixed devices may be technically difficult because of the narrow and concave pelvis. Several laparoscopic articulating tools have been introduced as an alternative to robotic systems. The aim of this study was to compare perioperative outcomes between laparoscopic low anterior resection using ArtiSential® and robot-assisted surgery for rectal cancer.

METHODS

This retrospective study included 682 patients who underwent laparoscopic or robotic low anterior resection  for rectal cancer from September 2018 to December 2021. Among them, 82 underwent laparoscopic surgery using ArtiSential® (group A) and 201 underwent robotic surgery (group B). A total of 73 [group A; 66.37 ± 11.62; group B 65.79 ± 11.34] patients were selected for each group using a propensity score matching analysis.

RESULTS

There was no significant difference in the baseline characteristics between group A and B. Mean operative time was longer in group B than A (163.5 ± 61.9 vs 250.1 ± 77.6 min, p < 0.001). Mean length of hospital stay was not significantly different between the two groups (6.2 ± 4.7 vs 6.7 ± 6.1 days, p = 0.617). Postoperative complications, reoperation, and readmission within 30 days after surgery were similar between the two groups. Pathological findings revealed that the circumferential resection margins were above 10 mm in both groups (11.00 ± 7.47 vs 10.17 ± 6.25 mm, p = 0.960). At least 12 lymph nodes were sufficiently harvested, with no significant difference in the number harvested between the groups (20.5 ± 9.9 vs 19.7 ± 7.3, p = 0.753).

CONCLUSIONS

Laparoscopic low anterior resection using ArtiSential® can achieve acceptable clinical and oncologic outcomes. ArtiSential®, a multi-joint and articulating device, may serve a feasible alternative approach to robotic surgery in rectal cancer.

Improved diagnostic performance of susceptibility-weighted imaging with compressed sensing-sensitivity encoding and neuromelanin-sensitive MRI for Parkinson's disease and atypical Parkinsonism

AIM

To verify the diagnostic performance of the loss of nigrosome-1 on susceptibility-weighted imaging (SWI) with compressed sensing-sensitivity encoding (CS-SENSE) and neuromelanin on neuromelanin-sensitive (NM) magnetic resonance imaging (MRI) for the diagnosis of Parkinson's disease (PD) and atypical Parkinsonism.

MATERIALS AND METHODS

A total of 195 patients who underwent MRI between October 2019 and February 2020, including SWI, with or without CS-SENSE, and NM-MRI, were reviewed retrospectively. Two neuroradiologists assessed the loss of nigrosome-1 on SWI and neuromelanin on the NM-MRI. The result of N-3-fluoropropyl-2-beta-carbomethoxy-3-beta-(4-iodophenyl) nortropane positron-emission tomography (PET) was set as the reference standard.

RESULTS

When CS-SENSE was applied for nigrosome-1 imaging on SWI, the non-diagnostic scan rate was lowered significantly from 19.3% (17/88) to 5.6% (6/107; p=0.004). Diagnosis of PD and atypical Parkinsonism based on the loss of nigrosome-1 on SWI and based on NM-MRI showed good diagnostic value (area under the curve [AUC] 0.821, 95% confidence interval [CI] = 0.755-0.875: AUC 0.832, 95% CI = 0.771-0.882, respectively) with a substantial inter-reader agreement (κ = 0.791 and 0.681, respectively). Combined SWI and neuromelanin had a similar discriminatory ability (AUC 0.830, 95% CI = 0.770-0.880). Similarly, the diagnosis of PD was excellent.

CONCLUSIONS

CS-SENSE may add value to the diagnostic capability of nigrosome-1 on SWI to reduce the nondiagnostic scan rates. Furthermore, loss of nigrosome-1 on SWI or volume loss of neuromelanin on NM-MRI may be helpful for diagnosing PD.

Monitoring of over-the-counter (OTC) and COVID-19 treatment drugs complement wastewater surveillance of SARS-CoV-2

BACKGROUND

The application of wastewater-based epidemiology to track the outbreak and prevalence of coronavirus disease (COVID-19) in communities has been tested and validated by several researchers across the globe. However, the RNA-based surveillance has its inherent limitations and uncertainties.

OBJECTIVE

This study aims to complement the ongoing wastewater surveillance efforts by analyzing other chemical biomarkers in wastewater to help assess community response (hospitalization and treatment) during the pandemic (2020-2021).

METHODS

Wastewater samples (n = 183) were collected from the largest wastewater treatment facility in Suffolk County, NY, USA and analyzed for COVID-19 treatment drugs (remdesivir, chloroquine, and hydroxychloroquine (HCQ)) and their human metabolites. We additionally monitored 26 pharmaceuticals including common over-the-counter (OTC) drugs. Lastly, we developed a Bayesian model that uses viral RNA, COVID-19 treatment drugs, and pharmaceuticals data to predict the confirmed COVID-19 cases within the catchment area.

RESULTS

The viral RNA levels in wastewater tracked the actual COVID-19 case numbers well as expected. COVID-19 treatment drugs were detected with varying frequency (9-100%) partly due to their instability in wastewater. We observed a significant correlation (R = 0.30, p < 0.01) between the SARS-CoV-2 genes and desethylhydroxychloroquine (DHCQ, metabolite of HCQ). Remdesivir levels peaked immediately after the Emergency Use Authorization approved by the FDA. Although, 13 out of 26 pharmaceuticals assessed were consistently detected (DF = 100%, n = 111), only acetaminophen was significantly correlated with viral loads, especially when the Omicron variant was dominant. The Bayesian models were capable of reproducing the temporal trend of the confirmed cases.

IMPACT

In this study, for the first time, we measured COVID-19 treatment and pharmaceutical drugs and their metabolites in wastewater to complement ongoing COVID-19 viral RNA surveillance efforts. Our results highlighted that, although the COVID-19 treatment drugs were not very stable in wastewater, their detection matched with usage trends in the community. Acetaminophen, an OTC drug, was significantly correlated with viral loads and confirmed cases, especially when the Omicron variant was dominant. A Bayesian model was developed which could predict COVID-19 cases more accurately when incorporating other drugs data along with viral RNA levels in wastewater.

Associations between total mercury, trace minerals, and blood health markers in Northwest Atlantic white sharks (Carcharodon carcharias)

The ecology and life-histories of white sharks make this species susceptible to mercury bioaccumulation; however, the health consequences of mercury exposure are understudied. We measured muscle and plasma total mercury (THg), health markers, and trace minerals in Northwest Atlantic white sharks. THg in muscle tissue averaged 10.0 mg/kg dry weight, while THg in blood plasma averaged 533 μg/L. THg levels in plasma and muscle were positively correlated with shark precaudal length (153-419 cm), and THg was bioaccumulated proportionally in muscle and plasma. Nine sharks had selenium:mercury molar ratios in blood plasma >1.0, indicating that for certain individuals the potential protective effects of the trace mineral were diminished, whereas excess selenium may have protected other individuals. No relationships between plasma THg and any trace minerals or health markers were identified. Thus, we found no evidence of negative effects of Hg bioaccumulation, even in sharks with very high THg.

Fungus isolated from dermatomycoses: a 9-month prospective study at Hospital Melaka

INTRODUCTION

Dermatomycoses are common superficial cutaneous fungal infections which affect the skin, nails and human hairs. It affects 20 to 25% of the world population. The causative fungus varies geographically across the globe. Study on dermatomycoses is crucial to identify the aetiological fungus involved locally. The study aimed to determine the causative fungus of superficial fungal infections of the skin, nail and hair in patients presented to Hospital Melaka.

METHODS

This was a prospective study conducted from 15th January 2022 till 15th October 2022 at Dermatology Clinic, Hospital Melaka. Subjects with clinical dermatomycoses were included in this study. The samples were collected from skin, nails and hairs clinically affected by tinea corporis/cruris/pedis, onychomycosis and tinea capitis respectively. A potassium hydroxide (KOH) study was performed on the sample in which the fungal hyphae/yeast positive subjects were sent for fungal culture and fungal PCR test.

RESULT

A total of 222 clinical samples from skin, nails and hairs with a clinical suspicion of dermatomycoses yielded fungal hyphae/yeast in KOH. Majority of the samples were collected from skin (138, 62.2%), followed by nails (65, 29.3%) and hairs (19, 8.6%). Male to female ratio was 1.18: 1. The age ranged from 2 to 87 with the median of 55.5-yearsold. Out of 222 samples, 150 (67.6%) were fungal culture positive. From fungal culture positive samples, 87 samples were from tinea corporis, 50 samples were from onychomycoses and 13 samples were from tinea capitis. Trichophyton rubrum (39, 44.8%) was the commonest dermatophyte isolated in tinea corporis/cruris/pedis. Nondermatophyte moulds (NDM, 35, 70%) were the main fungi isolated in onychomycosis. Microsporum canis (7/53.8%) was the principal causative fungus among patients with tinea capitis. Among 150 fungal culture positive samples, 76 were fungal PCR positive. Only 38 samples consistently isolated same fungal species in both fungal culture and PCR test.

CONCLUSION

Majority of tinea corporis and tinea capitis fungal culture isolated dermatophytes, especially Trichophyton rubrum and Microsporum canis, respectively. Non-dermatophyte moulds were mainly isolated in onychomycosis.

1,4-Dioxane removal in nitrifying sand filters treating domestic wastewater: Influence of water matrix and microbial inhibitors

1,4-Dioxane is a recalcitrant pollutant in water and is ineffectively removed during conventional water and wastewater treatment processes. In this study, we demonstrate the application of nitrifying sand filters to remove 1,4-dioxane from domestic wastewater without the need for bioaugmentation or biostimulation. The sand columns were able to remove 61 ± 10% of 1,4-dioxane on average (initial concentration: 50 μg/L) from wastewater, outperforming conventional wastewater treatment approaches. Microbial analysis revealed the presence of 1,4-dioxane degrading functional genes (dxmB, phe, mmox, and prmA) to support biodegradation being the dominant degradation pathway. Adding antibiotics (sulfamethoxazole and ciprofloxacin), that temporarily inhibited the nitrification process during the dosing period, showed a minor effect in 1,4-dioxane removal (6-8% decline, p < 0.05), suggesting solid resilience of the 1,4-dioxane-degrading microbial community in the columns. Columns amended with sodium azide significantly (p < 0.05) depressed 1,4-dioxane removal in the early stage of dosing but followed by a gradual increase of the removal over time to >80%, presumably due to a shift in the microbial community toward azide-resistant 1,4-dioxane degrading microbes (e.g., fungi). This study demonstrated for the first time the resilience of the 1,4-dioxane-degrading microorganisms during antibiotic shocks, and the selective enrichment of efficient 1,4-dioxane-degrading microbes after azide poisoning. Our observation could provide insights into designing better 1,4-dioxane remediation strategies in the future.

Sodium Alginate-Aldehyde Cellulose Nanocrystal Composite Hydrogel for Doxycycline and Other Tetracycline Removal

A novel composite hydrogel bead composed of sodium alginate (SA) and aldehyde cellulose nanocrystal (DCNC) was developed for antibiotic remediation through a one-step cross-linking process in a calcium chloride bath. Structural and physical properties of the hydrogel bead, with varying composition ratios, were analyzed using techniques such as BET analysis, SEM imaging, tensile testing, and rheology measurement. The optimal composition ratio was found to be 40% (SA) and 60% (DCNC) by weight. The performance of the SA-DCNC hydrogel bead for antibiotic remediation was evaluated using doxycycline (DOXY) and three other tetracyclines in both single- and multidrug systems, yielding a maximum adsorption capacity of 421.5 mg g^-1 at pH 7 and 649.9 mg g^-1 at pH 11 for DOXY. The adsorption mechanisms were investigated through adsorption studies focusing on the effects of contact time, pH, concentration, and competitive contaminants, along with X-ray photoelectron spectroscopy analysis of samples. The adsorption of DOXY was confirmed to be the synergetic effects of chemical reaction, electrostatic interaction, hydrogen bonding, and pore diffusion/surface deposition. The SA-DCNC composite hydrogel demonstrated high reusability, with more than 80% of its adsorption efficiency remaining after five cycles of the adsorption-desorption test. The SA-DCNC composite hydrogel bead could be a promising biomaterial for future antibiotic remediation applications in both pilot and industrial scales because of its high adsorption efficiency and ease of recycling.

The Need for Testing Isomer Profiles of Perfluoroalkyl Substances to Evaluate Treatment Processes

Many environmentally relevant poly-/perfluoroalkyl substances (PFASs) including perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) exist in different isomeric (branched and linear) forms in the natural environment. The isomeric distribution of PFASs in the environment and source waters is largely controlled by the source of contamination and varying physicochemical properties imparted by their structural differences. For example, branched isomers of PFOS are relatively more reactive and less sorptive compared to the linear analogue. As a result, the removal of branched and linear PFASs during water treatment can vary, and thus the isomeric distribution in source waters can influence the overall efficiency of the treatment process. In this paper, we highlight the need to consider the isomeric distribution of PFASs in contaminated matrices while designing appropriate remediation strategies. We additionally summarize the known occurrence and variation in the physicochemical properties of PFAS isomers influencing their detection, fate, toxicokinetics, and treatment efficiency.

Hydroxyl-radical based advanced oxidation processes can increase perfluoroalkyl substances beyond drinking water standards: Results from a pilot study

Advanced oxidation processes (AOPs) are popular technologies employed across the U.S. for wastewater reclamation and drinking water treatment of recalcitrant chemicals. Although there is consensus about the ineffectiveness of AOPs to treat perfluoroalkyl substances (PFASs; not polyfluoro compounds by definition here), there is a lack of field data demonstrating their impact on the transformation of unknown PFAS precursors during groundwater treatment. In this study, the fate of PFASs in seven pilot-scale AOPs, including four different technologies (UV/H₂O₂, UV/Cl₂, UV/TiO₂, and O₃/H₂O₂), was assessed at four drinking water systems across New York State (NYS), USA. Seven of 18 PFASs were detected in the influent at concentrations ranging from below method detection to 64 ng/L. Across all systems, all detected PFASs showed an increase in concentration after treatment presumably due to unknown precursor transformation with specific increases for perfluorobutane sulfonate (PFBS), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorohexane sulfonate (PFHxS), perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), and perfluorononanoic acid (PFNA) averaging 405 (range: 0 - 1220) %, 1.0 (-7 - 9) %, 3.8 (0 - 9.5) %, 3.3 (-11 - 13) %, 14 (0 - 48) %, 13 (3 - 25) %, and 2 (0 - 5.2) %, respectively. The increase in PFAS concentration was dependent on UV and oxidant dose, further confirming that transformation reactions were occurring due to AOPs similar to a total oxidizable precursor assay. At one of the sites, PFOA levels exceeded the current NYS drinking water standard of 10 ng/L after, but not before treatment, highlighting the importance of considering the potential impact of AOP on treated water quality when designing treatment systems for regulatory compliance. The increase in PFAS concentration in the AOP systems positively correlated (r = 0.91) with nitrate levels in groundwater, suggesting that onsite septic discharges may be an important source of PFAS contamination in these unsewered study areas. Results from this pilot-scale demonstration reveal that hydroxyl radical-based AOPs, although ineffective in treating PFASs, can help to reveal the true extent of PFAS contamination in source waters.

The invasive red seaweed, Dasysiphonia japonica, forms harmful algal blooms: Mortality in early life stage fish and bivalves and identification of putative toxins

In recent decades, the rate of introduction of non-indigenous macroalgae has increased. While invasive seaweeds often outcompete native species for substrata, their direct effects on marine life are rarely described. Here, we describe 'red water' events caused by the decay of blooms of the invasive red seaweed, Dasysiphonia japonica, in Great South Bay, NY, USA, and the ability of water from such events to induce rapid and significant mortality in larval and juvenile fish (Menidia beryllina, Menidia menidia, and Cyprinodon variegatus) and larval bivalves (Mercenaria mercenaria and Crassostrea virginica). All species studied experienced significant (p<0.05) reductions in survival when exposed to macroalgae in a state of decay, seawater in which the alga was previously decayed, or both. Both bivalve species experienced 50-60% increases in mortality when exposed to decaying D. japonica for ∼ one week, despite normoxic conditions. Among fish, significant increases (40-80%) in mortality were observed after 24 h exposure to decayed D. japonica and one-week exposures caused, on average, 90% mortality in larval M. beryllina, 50% mortality in juvenile (∼3 cm) M. menidia, and 50% mortality in larval C. variegatus. All fish and bivalve mortality occurred under normoxic conditions (dissolved oxygen (DO) >7 mg L^-1) and low ammonium levels (< 20 µM), with the exception of C. variegatus, which expired under conditions of decayed D. japonica coupled with reduced DO caused by the alga. Screening of water with decayed D. japonica using liquid chromatography-mass spectrometry revealed compounds with mass-to-charge ratios matching caulerpin, a known algal toxin that causes fish and shellfish mortality, and several other putative toxicants at elevated levels. Collectively, the high levels of mortality (50-90%) of larval and juvenile fish and bivalves exposed to decaying D. japonica under normoxic conditions coupled with the observation of 'red water' events in estuaries collectively indicate the red seaweed, D. japonica, can create harmful algal blooms (HABs).

Severe cutaneous adverse reactions: A 5-year retrospective study at Hospital Melaka, Malaysia, from December 2014 to February 2020

INTRODUCTION

Severe cutaneous adverse reactions (SCARs) are potentially lethal adverse drug reactions that involve the skin, mucous membranes, and internal organs, resulting in disability. SCARs include drug-induced epidermal necrolysis, which is Steven Johnson syndrome (SJS)/ Steven Johnson syndrome and toxic epidermal necrolysis overlap (SJS-TEN overlap)/ toxic epidermal necrolysis (TEN), drug reaction with eosinophilia and systemic symptoms (DRESS), acute generalised exanthematous pustulosis (AGEP), generalised bullous fixed drug eruption (GBFDE), and acute erythroderma. Awareness of local epidemiology of SCARs plays an important role in prescribing practices by healthcare provider. Recognition of SCARs enables the offending drug to be withdrawn immediately, which is the definitive treatment of SCARs.

MATERIALS AND METHODS

This is a retrospective study reviewing SCAR cases reported to the Malaysian Adverse Drug Reactions Advisory Committee (MADRAC) registry at the Department of Dermatology, Hospital Melaka, for 5 years and 3 months from December 2014 to February 2020.

RESULTS

A total of 41 SCARs cases were identified over the study duration. The incidence rate was 0.18%. All 41 cases require hospitalisations, with four cases (9.8%) managed in ICU and one mortality (2.4%) due to SJS-related complication. One patient had two episodes of SCARs. There were 22 male patients and 18 female patients. The majority were Malays (33, 80.5%), followed by Chinese (7, 17.1%) and Indonesian (1, 2.4%). There was no Indian patient with SCARs in this study. The mean age of patients was 47.2±17 years. Drug-induced epidermal necrolysis was the commonest type of SCARs (63.4%), and out of this, SJS accounted for the majority of cases (48.8%). Antibiotic was the main group of offending medication in this SCAR study (29.3%). The top five individual causative drugs of SCARs in sequence include allopurinol, phenytoin, carbamazepine, co-amoxiclav, and cephalexin. Allopurinol was the commonest culprit drug for drug-induced epidermal necrolysis and DRESS, phenytoin for acute erythroderma, and co-amoxiclav for AGEP.

CONCLUSION

SJS was the most common manifestation and Allopurinol was the commonest culprit drug for SCAR cases in our cohort.

Characteristics and quality of life in pemphigus patients

INTRODUCTION

Pemphigus is an autoimmune blistering disease affecting the skin and mucus membranes. It is a debilitating skin condition with painful bullae and erosions, which may limit the patient's daily activities. Therefore, measuring the quality of life (QoL) from the perspective of physical, functional, social, and emotional well-being is important to address the disease burden. This study aims to review the demography and assess the impact of disease on QoL in pemphigus patients at the Department of Dermatology, Hospital Melaka.

MATERIALS AND METHODS

This is a single-centre, crosssectional study on the characteristics and QoL among the pemphigus patients at the Department of Dermatology, Melaka General Hospital, from August 2020 to July 2021. Patients' information was collected, and each patient was assessed objectively on the disease severity physically using the Pemphigus Disease Area Index (PDAI) scoring system. The disease severity was then assessed subjectively, in which each participant was given three questionnaires to answer, namely the Dermatology Life Quality Index (DLQI), Visual Analogue Scale (VAS) for pain and itch, and Autoimmune Bullous Disease Quality of Life (ABQOL).

RESULTS

There were a total of 30 pemphigus patients (13 males, 17 females), with an average age of 54.0 ± 13.6 years. Our study population had low median PDAI score (2.0 ± 4.0) with low median DLQI (3.0 ± 8.0) and ABQOL (11.0 ± 12.0). The median VAS scores for pain (1.0 ± 2.0) and itch (2.0 ± 3.0) were also low. Patients with tertiary educational qualification reported higher median DLQI (10.0 ± 12.0, p = 0.016) and ABQOL (21.0 ± 23.0, p = 0.026). Significant correlation was neither observed between PDAI and DLQI scores nor observed between PDAI and ABQOL scores. The DLQI and ABQOL scores were not affected by gender, age, ethnicity, and duration of illness.

CONCLUSION

Most of the patients in our study cohort had low DLQI and ABQOL scores, with mild clinical severity, as evidenced by low PDAI and VAS scores for both pain and itch. Disease severity had no correlation with QoL in our study. However, educational level showed significant influence on the QoL.

Risk assessment for seafood consumers exposed to mercury and other trace elements in fish from Long Island, New York, USA

We determined concentrations of Hg, Pb, Cd, Cr, As, Ni, Ag, Se, Cu, and Zn in muscle tissue of six commonly consumed Long Island fish species (black seabass, bluefish, striped bass, summer flounder, tautog, and weakfish, total sample size = 1211) caught off Long Island, New York in 2018 and 2019. Long-term consumption of these coastal fish could pose health risks largely due to Hg exposure; concentrations of the other trace elements were well below levels considered toxic for humans. By combining the measured Hg concentrations in the fish (means ranging from 0.11 to 0.27 mg/kg among the fish species), the average seafood consumption rate, and the current US EPA Hg reference dose (0.0001 mg/kg/d), it was concluded that seafood consumption should be limited to four fish meals per month for adults for some fish (bluefish, tautog) and half that for young children. Molar ratios of Hg:Se exceeded 1 for some black seabass, bluefish, tautog, and weakfish.

Occurrence and removal of PPCPs from on-site wastewater using nitrogen removing biofilters

The presence of pharmaceuticals and personal care products (PPCPs) in the environment is primarily the result of discharge of waste, including from onsite wastewater treatment systems (OWTSs) which are employed by 25% of homes in the United States. However, the occurrence and removal of PPCPs in OWTSs is not well understood, particularly given the large diversity in PPCP compounds as well as in OWTS designs. In this study, we monitored 26 different PPCPs in 13 full-scale nitrogen removing biofilters (NRBs), an innovative/alternative type of OWTS that utilizes an overlying sand layer and an underlying woodchip/sand layer to simultaneously remove nitrogen and other wastewater-derived contaminants. The specific objectives of this study were (i) to measure the occurrence of PPCPs in septic tank effluent (STE) that served as an influent to NRBs, (ii) to quantify PPCP removal in three types of NRB configurations (n = 13), and (iii) to evaluate PPCP removal with depth and environmental conditions in NRBs. Aqueous samples were taken during 42 separate sampling events during 2016 - 2019 and analyzed by liquid chromatography tandem mass spectrometry. Analysis of the STE samples yielded detection of 23 of the 26 PPCPs, with caffeine being the most abundant and frequently detected compound at 52,000 ng/L (range: 190 - 181,000 ng/L), followed by acetaminophen and paraxanthine at 47,500 ng/L (190 - 160,000 ng/L), and 34,300 ng/L (430 - 210,000 ng/L), respectively. Cimetidine, fenofibrate, and warfarin were the only compounds not detected. The average removal of PPCPs by NRBs ranged from 58% to >99% for the various compounds. PPCP removal as a function of depth in the systems showed that 50 to >99% of the observed removal was achieved within the top oxic layer (0 - 46 cm) of the NRBs for 19 analytes. Seven of the compounds had >85% removal by the same depth. These results indicate that NRBs are effective at removing PPCPs and that a large portion of the removal is achieved within the oxic nitrifying layer of the NRBs. Overall, the removal of PPCPs in NRBs was comparable (n = 8) or better (n = 15) than that observed for conventional wastewater treatment plants.

Mid-treatment Fluorodeoxyglucose Positron Emission Tomography in Human Papillomavirus-related Oropharyngeal Squamous Cell Carcinoma Treated with Primary Radiotherapy: Nodal Metabolic Response Rate can Predict Treatment Outcomes

AIMS

To evaluate whether biomarkers derived from fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) performed prior to (prePET) and during the third week (interim PET; iPET) of radiotherapy can predict treatment outcomes in human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPC).

MATERIALS AND METHODS

This retrospective analysis included 46 patients with newly diagnosed OPC treated with definitive (chemo)radiation and all patients had confirmed positive HPV status (HPV+OPC) based on p16 immunohistochemistry. The maximum standardised uptake value (SUV_max), metabolic tumour volume (MTV) and total lesional glycolysis (TLG) of primary, index node (node with the highest TLG) and total lymph nodes and their median percentage (≥50%) reductions in iPET were analysed, and correlated with 5-year Kaplan-Meier and multivariable analyses (smoking, T4, N2b-3 and AJCC stage IV), including local failure-free survival, regional failure-free survival, locoregional failure-free survival (LRFFS), distant metastatic failure-free survival (DMFFS), disease-free survival (DFS) and overall survival.

RESULTS

There was no association of outcomes with prePET parameters observed on multivariate analysis. A complete metabolic response of primary tumour was seen in 13 patients; the negative predictive value for local failure was 100%. More than a 50% reduction in total nodal MTV provided the best predictor of outcomes, including LRFFS (88% versus 47.1%, P = 0.006, hazard ratio = 0.153) and DFS (78.2% versus 41.2%, P = 0.01, hazard ratio = 0.234). More than a 50% reduction in index node TLG was inversely related to DMFFS: a better nodal response was associated with a higher incidence of distant metastatic failure (66.7% versus 100%, P = 0.009, hazard ratio = 3.0).

CONCLUSION

The reduction (≥50%) of volumetric nodal metabolic burden can potentially identify a subgroup of HPV+OPC patients at low risk of locoregional failure but inversely at higher risk of distant metastatic failure and may have a role in individualised adaptive radiotherapy and systemic therapy.

Association between autophagy and KRAS mutation with clinicopathological variables in colorectal cancer patients

Autophagy is a host defensive mechanism responsible for eliminating harmful cellular components through lysosomal degradation. Autophagy has been known to either promote or suppress various cancers including colorectal cancer (CRC). KRAS mutation serves as an important predictive marker for epidermal growth factor receptor (EGFR)-targeted therapies in CRC. However, the relationship between autophagy and KRAS mutation in CRC is not well-studied. In this single-centre study, 92 formalin-fixed paraffin-embedded (FFPE) tissues of CRC patients (42 Malaysian Chinese and 50 Indonesian) were collected and KRAS mutational status was determined by quantitative PCR (qPCR) (n=92) while the expression of autophagy effector (p62, LC3A and LC3B) was examined by immunohistochemistry (IHC) (n=48). The outcomes of each were then associated with the clinicopathological variables (n=48). Our findings demonstrated that the female CRC patients have a higher tendency in developing KRAS mutation in the Malaysian Chinese population (p<0.05). Expression of autophagy effector LC3A was highly associated with the tumour grade in CRC (p<0.001) but not with other clinicopathological parameters. Lastly, the survival analysis did not yield a statistically significant outcome. Overall, this small cohort study concluded that KRAS mutation and autophagy effectors are not good prognostic markers for CRC patients.

Removal of 1,4-dioxane during on-site wastewater treatment using nitrogen removing biofilters

The presence and release of 1,4-dioxane to groundwater from onsite-wastewater treatment systems (OWTS), which represent 25% of the total wastewater treatment in the U.S., has not been studied to date. In this study we monitored 1,4-dioxane in six septic tank effluents (STE) and receiving OWTS installed at residences on Long Island (LI), NY, for a period of 15 months. We specifically evaluated the performance of Nitrogen Removing Biofilters (NRBs) as an innovative/alternative-OWTS, consisting of a top sand layer and a bottom woodchip/sand layer, to simultaneously remove nitrogen and 1,4-dioxane. 1,4-Dioxane levels in STE (mean: 1.49 μg L^-1; range: 0.07-8.45 μg L^-1; n = 37) were on average > 15 times higher than tap water from these residences, demonstrating that 1,4-dioxane primarily originated from the use of household products. NRBs were effective in removing both 1,4-dioxane and total nitrogen with an overall removal efficiency of 56 ± 20% and 88 ± 12%, respectively. The majority of 1,4-dioxane removal (~80%) occurred in the top oxic layer of the NRBs. The detection of functional genes (dxmB, prmA, and thmA), which encode for metabolic and co-metabolic 1,4-dioxane degradation, in NRBs provides the first field evidence of aerobic microbial degradation of 1,4-dioxane occurring in a wastewater system. Given that there are ~500,000 conventional OWTS on LI, the 1,4-dioxane discharge to groundwater from residential wastewater was estimated at 195 ± 205 kg yr ^-1, suggesting high risk of contamination to shallow aquifers. The results also demonstrate that installation of NRBs can reduce 1,4-dioxane to levels even lower than the NY State drinking water standard of 1 μg L^-1.

Effects of methylmercury on the early life stages of an estuarine forage fish using two different dietary sources

Marine fish accumulate methylmercury (MeHg) to elevated concentrations, often higher than in freshwater systems. As a neurotoxic compound, high MeHg tissue concentrations could affect fish behavior which in turn could affect their populations. We examined the sublethal effects of MeHg on larvae of the Sheepshead minnow (Cyprinodon variegatus), an estuarine fish, using artificial or natural diets with varying MeHg concentrations (0-4.8 ppm). Larvae were fed control and MeHg-contaminated diets at low or normal (10% of their body mass) daily food rations from 7 to 29 days when they reached juvenile stage. Growth, respiration, swimming activity and prey capture ability were assessed. Food ration affected Hg toxicity in our study. Natural diets containing 3.2 ppm MeHg had no impacts on growth and swimming in fish that were fed normal food rations but depressed growth and swimming at low food rations. MeHg toxicity did not differ between artificial and natural foods, however fish accumulated more MeHg from the former. Artificial food containing 4.8 ppm MeHg only affected prey capture after 21 days of exposure. Sheepshead minnows, a forage fish species occupying a low trophic level in coastal waters, can be MeHg tolerant, especially when food is abundant, and can serve as an enriched Hg source for higher trophic level predators.

Metal concentrations in coastal sharks from The Bahamas with a focus on the Caribbean Reef shark

Over the last century anthropogenic activities have rapidly increased the influx of metals and metalloids entering the marine environment, which can bioaccumulate and biomagnify in marine top consumers. This may elicit sublethal effects on target organisms, having broad implications for human seafood consumers. We provide the first assessment of metal (Cd, Pb, Cr, Mn, Co, Cu, Zn, As, Ag, and THg) and metalloid (As) concentrations in the muscle tissue of coastal sharks from The Bahamas. A total of 36 individual sharks from six species were evaluated, spanning two regions/study areas, with a focus on the Caribbean reef shark (Carcharhinus perezi), and to a lesser extent the tiger shark (Galeocerdo cuvier). This is due their high relative abundance and ecological significance throughout coastal Bahamian and regional ecosystems. Caribbean reef sharks exhibited some of the highest metal concentrations compared to five other species, and peaks in the concentrations of Pb, Cr, Cu were observed as individuals reached sexual maturity. Observations were attributed to foraging on larger, more piscivorous prey, high longevity, as well a potential slowing rate of growth. We observed correlations between some metals, which are challenging to interpret but may be attributed to trophic level and ambient metal conditions. Our results provide the first account of metal concentrations in Bahamian sharks, suggesting individuals exhibit high concentrations which may potentially cause sublethal effects. Finally, these findings underscore the potential toxicity of shark meat and have significant implications for human consumers.

Lactobacillus-fermented milk products attenuate bone loss in an experimental rat model of ovariectomy-induced post-menopausal primary osteoporosis

AIM

In this study, we investigated the anti-osteoporotic effect of two fermented milk products (FMPs) fermented by Lactobacillus plantarum A41 and Lactobacillus fermentum SRK414 on a rat model of ovariectomy-induced post-menopausal primary osteoporosis.

METHODS AND RESULTS

The two Lactobacillus FMPs increased the bone volume and bone mineral density (BMD) in ovariectomized (OVX) rats, and normalized the bone biomarkers in the serum. Additionally, they altered the gene expression levels of bone-metabolism-related markers. Furthermore, the two Lactobacillus FMPs downregulated bone-apoptosis-related genes stimulated by ovariectomy. Interestingly, the Lactobacillus FMPs decreased the levels of inflammation markers in the serum, bone, ileum and colon of the rats. Gut bacterial populations were also affected upon FMP treatment due to increase in the abundance of the genus Lactobacillus and Faecalibacterium prausnitzii.

CONCLUSIONS

Milk products fermented by L. plantarum A41 and L. fermentum SRK414 can exhibit anti-osteoporotic effects on post-menopausal osteoporosis via regulating the expression of bone-metabolism-related markers.

SIGNIFICANCE AND IMPACT OF THE STUDY

The two Lactobacillus FMPs used in the study can be an ideal method that has its potential of treating post-menopausal osteoporosis instead of drug treatments.

Metal Organic Framework-Polyethersulfone Composite Membrane for Iodine Capture

A variety of metal organic frameworks (MOFs) were synthesized and evaluated for their iodine adsorption capacity. Out of the MOFs tested, ZIF-8 showed the most promising result with an iodine vapor uptake of 876.6 mg/g. ZIF-8 was then incorporated into a polymer, polyethersulfone (PES), at different proportions to prepare mixed matrix membranes (MMMs), which were then used to perform further iodine adsorption experiments. With a mixing ratio of 40 wt % of ZIF-8, the iodine adsorption capacity reached 1387.6 mg/g, wherein an astounding 60% improvement in adsorption was seen with the MMMs prepared compared to the original ZIF-8 powder.

Mapping of a New Deformation Region around ^{62}Ti

We performed the first direct mass measurements of neutron-rich scandium, titanium, and vanadium isotopes around the neutron number 40 at the RIKEN RI Beam Factory using the time-of-flight magnetic-rigidity technique. The atomic mass excesses of ^{58-60}Sc, ^{60-62}Ti, and ^{62-64}V were measured for the first time. The experimental results show that the two-neutron separation energies in the vicinity of ^{62}Ti increase compared to neighboring nuclei. This shows that the masses of Ti isotopes near N=40 are affected by the Jahn-Teller effect. Therefore, a development of Jahn-Teller stabilization appears below the Cr isotopes, and the systematics in Sc, Ti, and V isotopes suggest that ^{62}Ti is located close to the peak of the Jahn-Teller effect.

How Different is the Core of ^{25}F from ^{24}O_{g.s.} ?

The structure of a neutron-rich ^{25}F nucleus is investigated by a quasifree (p,2p) knockout reaction at 270A  MeV in inverse kinematics. The sum of spectroscopic factors of π0d_{5/2} orbital is found to be 1.0±0.3. However, the spectroscopic factor with residual ^{24}O nucleus being in the ground state is found to be only 0.36±0.13, while those in the excited state is 0.65±0.25. The result shows that the ^{24}O core of ^{25}F nucleus significantly differs from a free ^{24}O nucleus, and the core consists of ∼35% ^{24}O_{g.s.}. and ∼65% excited ^{24}O. The result may infer that the addition of the 0d_{5/2} proton considerably changes neutron structure in ^{25}F from that in ^{24}O, which could be a possible mechanism responsible for the oxygen dripline anomaly.

Impact of groundwater quality and associated byproduct formation during UV/hydrogen peroxide treatment of 1,4-dioxane

In this study, a semi-batch, bench-scale UV/hydrogen peroxide (UV/H₂O₂) advanced oxidation process system was used to investigate how typical groundwater quality parameters (pH, alkalinity, natural organic matter (NOM), nitrate, and iron) influence the treatment of 1,4-dioxane. Deionized (DI) water spiked with 1,4-dioxane (100 μg L^-1), treated using H₂O₂ (10 mg L^-1) in a commercially available UV system (40 W low-pressure lamp) showed an UV fluence-based first-order rate constant (k') and electrical energy-per-order (EEO) of 4.32✕10^-3 cm²-mJ^-1 and 0.15 kWh-m^-3-order^-1, respectively. The most abundant byproduct generated in spiked-DI water was oxalic acid (up to 55 μg L^-1), followed by formic and acetic acids. The k' showed no significant difference at pH ranging from 5 to 7 and at low alkalinity concentrations (<20 mg-CaCO₃ L^-1), typical of sandy aquifers. The k' declined by up to 85% with increasing NOM concentration. Elevated production (up to ∼400% increase) of aldehydes and organic acids was observed in NOM-spiked water, implying that NOM is a significant byproduct precursor during UV/H₂O₂ treatment. High NO₃^- concentration (10 mg-N L^-1) in source water reduced the k' by 25%, while no significant impact was observed at lower concentrations (<2 mg-N L^-1). Addition of Fe(II) at 0.5 mg-L^-1 resulted in an instantaneous Fenton-reaction-assisted removal of ∼10% 1,4-dioxane in the presence of H₂O₂, but did not enhance the performance of UV/H₂O₂ treatment over time. In contrast, both Fe(II) and Fe(III) addition lowered the k' by 15-27%. The decline of k' observed in these experiments was attributed to reduced UVT (Fe), ^.OH radical scavenging (pH), or both (NO₃^-, NOM). Treatment of groundwater samples collected from three 1,4-dioxane-contaminated wells located in Long Island, NY, showed k' values of 13-40% lower than what was observed for DI water due to radical scavenging from a combination of high NO₃^- and NOM in the samples. A multiple linear-regression model, developed using water quality data as model input, showed good agreement with field observations (paired t-test: p > 0.05) in predicting k' for the removal of 1,4-dioxane from groundwater. This study provides the first systematic evaluation of the impacts of groundwater quality on UV/H₂O₂ process to remove environmentally relevant levels of 1,4-dioxane and reports standardized performance-related parameters to aid in the design and evaluation of full-scale systems.

P313ADGRL2 is an essential surface molecule for cardiac lineage specification and heart development

Background

Specific surface markers that enable monitoring of cell subsets would be valuable for establishing the conditions under which pluripotent stem cells (PSCs) differentiate into cardiac progenitor cells (CPCs) and cardiomyocytes (CMCs).

Methods and results

To verify whether a specific marker is expressed during heart development, we assessed its expression using the CLARITY technique. After immersion in a solution with a refractive index matching that of the CLARITY hybrid, the mouse embryo became transparent. After immunostaining the cleared embryo sample, Adgrl2 was exclusively observed in cardiac cells expressing α-SA at embryonic day E9.5 and E10.5. Our clarified 3D images and movies show that four chambers of the heart are fully developed at E10.5 but not at E9.5. At E9.5, Adgrl2 is observed at the ventricle and atrium, while Adgrl2 is present in all chambers of the heart at E10.5. Next, we performed LacZ (β-Gal) staining in heterozygous Adgrl2 KO embryos to evaluate Adgrl2 expression. As a result, LacZ staining showed that Adgrl2 was predominantly expressed in the heart during the embryonic developmental stage. Adgrl2 knockout in mice was embryonically lethal because of severe heart, but not vascular, defects. To examine the use of Adgrl2 as a bona fide CPC marker during heart development, we tracked Adgrl2 expression during early embryonic development. The heart of Adgrl2−/− embryos at E10.5 exhibited occlusion of the RV, and the expression levels of Gata4 and Nkx2.5 were not as high as those in wild-type and Adgrl2+/− embryos. Interestingly, the heart of Adgrl2−/− embryos, unlike those of wild-type and Adgrl2+/− embryos between E13.5 and E15.5 had a single ventricle revealing a ventricular septal defect. The specific expression pattern of Adgrl2 in PSC-derived cardiac lineage cells as well as in embryonic heart, adult mice, and human heart tissues.

Conclusion

We demonstrate that Adgrl2 plays a pivotal and functional role across all strata of the cardiomyogenic lineage, as early as the precursor stage of heart development. These findings shed light on heart development and regeneration.

Acknowledgement/Funding

Grants from “Strategic Center of Cell and Bio Therapy” (grant number: HI17C2085) and “Korea Research-Driven Hospital” (HI14C1277)

P3479Sequential stimulation and inhibition of lysophosphatidic acid receptor 4 are critical for cardiac differentiation and repair

Background

The clinical application of cell therapy to repair the damaged heart needs to understand the precise differentiation process of stem cells and the characteristics of cardiac progenitor cells.

Purpose

We examined the cardiac-specific markers that expressed on the cell surface and determined their functional significance during cardiac differentiation.

Methods and results

We screened cell-surface expressing proteins on cardiac progenitor cells at differentiation day 3 compared to undifferentiated pluripotent stem cells (PSCs). Among candidates, we identified lysophosphatidic acid receptor 4 (LPAR4) that is a G protein-coupled receptor. During in vitro differentiation of mouse PSCs toward cardiac cells, LPAR4 expression peaked for 3–5 days and then and declined immediately. Also in vivo, LPAR4 was specifically expressed in the early stage of heart development in embryos and disappeared completely in adults, suggesting that stimulatory signal of LPAR4 at an early stage should be shut off for further progression of differentiation. We next have identified the LPAR4 downstream signaling molecule, p38MAPK, by comparing PSCs and LPAR4 knockdown PSCs. In both mouse and human PSCs, ODP (LPAR4 specific agonist) followed by p38MAPK blocker (SB203580) treatment significantly increased cardiac differentiation efficiency. Furthermore, we investigated whether LPAR4 is the maker for adult cardiac progenitor cells. We found that LPAR4-positive cells were rarely present in normal adult mouse hearts, but LPAR4-positive cells were increased when the heart was damaged. LPAR4-positive cells from adult hearts differentiated into cardiomyocytes. After myocardial infarction (MI), the sequential stimulation and inhibition of LPAR4 with ODP and p38MAPK blocker resulted in the reduction of infarct size and improvement of left ventricular dysfunction.

Conclusion

We demonstrated that LPAR4 is a cardiac progenitor-specific marker and its functional significance during cardiac differentiation and regeneration. Our findings provide a new insight in cell-free cardiac repair by the modulation of progenitor-specific downstream signaling.

Acknowledgement/Funding

Grants from “Strategic Center of Cell and Bio Therapy” (grant number: HI17C2085) and “Korea Research-Driven Hospital” (HI14C1277)

Microbial generation of elemental mercury from dissolved methylmercury in seawater

Elemental mercury (Hg⁰) formation from other mercury species in seawater results from photoreduction and microbial activity, leading to possible evasion from seawater to overlying air. Microbial conversion of monomethylmercury (MeHg) to Hg0 in seawater remains unquantified. A rapid radioassay method was developed using gamma-emitting ²⁰³Hg as a tracer to evaluate Hg⁰ production from Hg(II) and MeHg in the low pM range. Bacterioplankton assemblages in Atlantic surface seawater and Long Island Sound water were found to rapidly produce Hg⁰, with production rate constants being directly related to bacterial biomass and independent of dissolved Hg(II) and MeHg concentrations. About 32% of Hg(II) and 19% of MeHg were converted to Hg⁰ in 4 d in Atlantic surface seawater containing low bacterial biomass, and in Long Island Sound water with higher bacterial biomass, 54% of Hg(II) and 8% of MeHg were transformed to Hg⁰. Decreasing temperatures from 24°C to 4°C reduced Hg⁰ production rates cell^-1 from Hg(II) 3.3 times as much as from a MeHg source. Because Hg⁰ production rates were linearly related to microbial biomass and temperature, and microbial mercuric reductase was detected in our field samples, we inferred that microbial metabolic activities and enzymatic reactions primarily govern Hg⁰ formation in subsurface waters where light penetration is diminished.

Trophodynamics and mercury bioaccumulation in reef and open-ocean fishes from The Bahamas with a focus on two teleost predators

Identifying prey resource pools supporting fish biomass can elucidate trophic pathways of pollutant bioaccumulation. We used multiple chemical tracers (carbon [δ¹³C] and nitrogen [δ¹⁵N] stable isotopes and total mercury [THg]) to identify trophic pathways and measure contaminant loading in upper trophic level fishes residing at a reef and open-ocean interface near Eleuthera in the Exuma Sound, The Bahamas. We focused predominantly on the trophic pathways of mercury bioaccumulation in dolphinfish Coryphaena hippurus and wahoo Acanthocybium solandri, 2 commonly consumed pelagic sportfish in the region. Despite residing within close proximity to productive and extensive coral reefs, both dolphinfish and wahoo relied almost exclusively on open-ocean prey over both short and long temporal durations. A larger isotopic niche of dolphinfish suggested a broader diet and some potential prey differentiation between the 2 species. THg concentrations in dolphinfish (0.2 ± 0.1 ppm) and wahoo (0.3 ± 0.3 ppm) were mostly below recommended guidelines for humans (US Environmental Protection Agency (EPA) = 0.3 ppm, US Food and Drug Administration (FDA)= 1.0 ppm) and were within ranges previously reported for these species. However, high THg concentrations were observed in muscle and liver tissue of commonly consumed reef-associated fishes, identifying a previously unrecognized route of potentially toxic Hg exposure for human consumers on Eleuthera and neighboring islands.

Bioaccumulation and trophic transfer of 137Cs in marine and freshwater plankton

An experimental study was conducted to investigate the trophic transfer of ¹³⁷Cs in marine and freshwater food chains, focusing on phytoplankton, zooplankton, and planktivorous fish. Algal concentration factors were 278 in freshwater and 69 in seawater. The weight-normalized uptake rate constants of ¹³⁷Cs were similar for both freshwater daphnids and marine copepods. Most of the ¹³⁷Cs in marine copepods was in the exoskeleton followed by polar and non-polar components. In freshwater daphnids, ¹³⁷Cs was highest in the polar fractions followed by exoskeleton and low amounts in the non-polar components. Fish that fed on contaminated marine copepods assimilated ¹³⁷Cs with an efficiency of 88%, while 91% was assimilated from freshwater daphnids. A bioaccumulation model demonstrated that diet accounted for ≤3% of the total body burden of ¹³⁷Cs in marine zooplankton and ≤12% in freshwater zooplankton, but ≥99% of the total body burden in fish. Rate constants of ¹³⁷Cs loss from fish following aqueous exposure were 0.2 d^-1 and 0.4 d^-1 in marine and freshwater conditions, respectively, but only 0.06 d^-1 and 0.3 d^-1, respectively, following dietary exposure. This model also indicates that trophic transfer factors from zooplankton to fish are up to 2.2 for marine conditions and up to 0.6 for freshwater. ¹³⁷Cs is unusual among metals in that it enters marine food chains primarily from the aqueous phase into zooplankton, from which it is highly assimilated by fish, resulting in detectable ¹³⁷Cs in fish tissues.

Extraction of the Landau-Migdal Parameter from the Gamow-Teller Giant Resonance in ^{132}Sn

The key parameter to discuss the possibility of the pion condensation in nuclear matter, i.e., the so-called Landau-Migdal parameter g^{'}, was extracted by measuring the double-differential cross sections for the (p,n) reaction at 216  MeV/u on a neutron-rich doubly magic unstable nucleus, ^{132}Sn with the quality comparable to data taken with stable nuclei. The extracted strengths for Gamow-Teller (GT) transitions from ^{132}Sn leading to ^{132}Sb exhibit the GT giant resonance (GTR) at the excitation energy of 16.3±0.4(stat)±0.4(syst)  MeV with the width of Γ=4.7±0.8  MeV. The integrated GT strength up to E_{x}=25  MeV is S_{GT}^{-}=53±5(stat)_{-10}^{+11}(syst), corresponding to 56% of Ikeda's sum rule of 3(N-Z)=96. The present result accurately constrains the Landau-Migdal parameter as g^{'}=0.68±0.07, thanks to the high sensitivity of the GTR energy to g^{'}. In combination with previous studies on the GTR for ^{90}Zr and ^{208}Pb, the result of this work shows the constancy of this parameter in the nuclear chart region with (N-Z)/A=0.11 to 0.24 and A=90 to 208.

Magic Nature of Neutrons in ^{54}Ca: First Mass Measurements of ^{55-57}Ca

We perform the first direct mass measurements of neutron-rich calcium isotopes beyond neutron number 34 at the RIKEN Radioactive Isotope Beam Factory by using the time-of-flight magnetic-rigidity technique. The atomic mass excesses of ^{55-57}Ca are determined for the first time to be -18650(160), -13510(250), and -7370(990)  keV, respectively. We examine the emergence of neutron magicity at N=34 based on the new atomic masses. The new masses provide experimental evidence for the appearance of a sizable energy gap between the neutron 2p_{1/2} and 1f_{5/2} orbitals in ^{54}Ca, comparable to the gap between the neutron 2p_{3/2} and 2p_{1/2} orbitals in ^{52}Ca. For the ^{56}Ca nucleus, an open-shell property in neutrons is suggested.

Depigmentation efficacy of galacturonic acid through tyrosinase regulation in B16 murine melanoma cells and a three-dimensional human skin equivalent

Sugar is a well-known cosmetic ingredient for moisturizing skin with minimal side-effects. Several reports have demonstrated an antimelanogenic effect of sugar in melanocytes. We evaluated the whitening efficacy of galacturonic acid (GA), the main component of pectin, as an anti-melanogenic agent. GA significantly suppressed melanin synthesis and secretion in a concentration-dependent manner in α-melanocyte stimulating hormone-treated B16 melanoma cells, and inhibited tyrosinase activity and expression at a dose of 10 mmol/L. In a three-dimensional human skin equivalent (MelanoDerm), GA clearly brightened tissue colour. Haematoxylin and eosin and Fontana-Masson (F&M) staining of tissue sections revealed decreased melanin production without skin tissue collapse in the presence of GA. Interestingly, GA dramatically suppressed gene expression of the melanogenic proteins tyrosinase, tyrosinase-related protein (TYRP)-1 and microphthalmia-associated transcription factor, but not TYRP-2. The results support the utility of GA as an effective candidate antimelanogenic agent.

A graphene mesh as a hybrid electrode for foldable devices

A graphene mesh with arrays of micro-holes was fabricated on a polymer substrate using photolithography for use as an electrode in flexible devices. The optimal mesh structure with high optical transmittance and electrical conductivity was designed using a finite element method, in which the conductivity of the mesh was simulated as a function of structure, size, and periodicity of the hole array. The sheet resistance of the graphene mesh was lowered to that of a graphene monolayer by chemical doping and found to be 330 Ω Sq^-1 at 98.5% transparency. The figure of merit of the doped graphene mesh was calculated to be 106 at 98% transmittance, a value that has not yet been reported for any conventional transparent electrode material. Due to strong bonding between the polymer and substrate, the hybrid electrode composed of a silver nanowire (AgNW)/graphene mesh coated with an over-coating layer exhibited more stable electrical characteristics during mechanical fatigue deformation compared to a hybrid film composed of a AgNW/graphene sheet. The AgNW/graphene sheet underwent breakdown at less than 20 000 cycles in cyclic bending tests with 6.5% strain, but the AgNW/graphene mesh showed a 38% increase in resistance at 20 000 cycles and no breakdown even at 100 000 cycles. Therefore, in this study, we propose a hybrid structure composed of a AgNW/graphene mesh, which is optically and mechanically superior to AgNW/graphene sheets, and therefore suitable for application as a transparent electrode in foldable devices with long-term stability.

Bioaccumulation of methylmercury in a marine diatom and the influence of dissolved organic matter

The largest bioconcentration step of most metals, including methylmercury (MeHg), in aquatic biota is from water to phytoplankton, but the extent to which dissolved organic matter (DOM) affects this process for MeHg largely remains unexplored in marine systems. This study investigated the influence of specific sulfur-containing organic compounds and naturally occurring DOM on the accumulation of MeHg in a marine diatom Thalassiosira pseudonana. Initial uptake rate constants and volume concentration factors (VCFs) of MeHg were calculated to evaluate MeHg enrichment in algal cells in the presence of a range of organic compound concentrations. At environmentally realistic and higher concentrations, the addition of glycine and methionine had no effect on algal MeHg uptake, but thiol-containing compounds such as cysteine and thioglycolic acid reduced MeHg accumulation in algal cells at high added concentrations (> 100 times higher than naturally occurring concentrations). However, environmentally realistic concentrations of glutathione, another thiol-containing compound as low as 10 nM, resulted in a decline of ~ 30% in VCFs, suggesting its possible importance in natural waters. Humic acid additions of 0.1 and 0.5 mg C/L also reduced MeHg VCFs by ~ 15% and ~ 25%, respectively. The bioaccumulation of MeHg for T. pseudonana in coastal waters with varying levels of dissolved organic carbon (DOC) was inversely correlated with bulk DOC concentrations. Generally, naturally occurring DOM, particularly certain thiol-containing compounds, can reduce MeHg uptake by phytoplankton.

Telephone Reminders to Reduce Non-Attendance Rate for Endoscopy

Non-attendance at clinics and endoscopy units wastes resources and lengthens waiting lists. In a previous study elsewhere, a substantial proportion of patients claimed to have forgotten their appointment. We therefore assessed the value of telephoning patients a week before their booked day-case endoscopy. An observation period of two months was followed by an intervention period of two months in which patients were contacted by phone and asked if they wished to come for their investigation. A maximum of three separate attempts were made to contact each patient. Patients cancelling the appointment were replaced by others on the reserve list. The non-attendance rate was expressed as the percentage of unused beds. During the observation period 56 patients were admitted and 18 beds were unused. During the intervention period it was possible to contact 73 of 88 patients and 8 of these cancelled. 87 beds were available and 83 patients were admitted. When clerical error, overbooking and failure to replace patients were taken into account, the non-attendance rate declined from 23.3% during the observation period to 5.7% during the intervention period (P<0.05). The intervention seemed more effective in reducing non-attendance in outpatients referrals (0/48) than in general practitioner referrals (5/40).

Bioaccumulation of methylmercury in a marine copepod

Methylmercury (MeHg) is known to biomagnify in marine food chains, resulting in higher concentrations in upper trophic level animals than their prey. To better understand how marine copepods, an important intermediate between phytoplankton and forage fish at the bottom of the food chain, assimilate and release MeHg, the authors performed a series of laboratory experiments using the gamma-emitting radiotracer ²⁰³ Hg²⁺ and Me²⁰³ Hg with the calanoid copepod Acartia tonsa. Assimilation efficiencies of Hg²⁺ and MeHg ranged from 25% to 31% and 58% to 79%, respectively, depending on algal diets. Assimilation efficiencies were positively related to the fraction of Hg in the cytoplasm of the algal cells that comprised their diet. Efflux rates of Hg²⁺ (0.29/d) and MeHg (0.21/d) following aqueous uptake were similar, but efflux rates following dietary uptake were significantly lower for MeHg (0.11-0.22/d) than Hg²⁺ (0.47-0.66/d). The calculated trophic transfer factors in copepods were >1 for MeHg and consistently low (≤0.2) for Hg²⁺ . The authors used the parameters measured to quantitatively model the relative importance of MeHg sources (water or diet) for copepods and to predict the overall MeHg concentrations in copepods in different marine environments. In general, MeHg uptake from the diet accounted for most of the body burden in copepods (>50%). For an algal diet with a MeHg dry weight bioconcentration factor ≥10⁶ , >90% of a copepod's MeHg body burden can be shown to derive from the diet. The model-predicted MeHg concentrations in the copepods were comparable to independent measurements for copepods in coastal and open-ocean regions, implying that the measured parameters and model are applicable to natural waters. Environ Toxicol Chem 2017;36:1287-1293. © 2016 SETAC.

Optimisation of Reactive Black 5 dye removal by electrocoagulation process using response surface methodology

In this work, a regression model obtained from response surface methodology (RSM) was proposed for the electrocoagulation (EC) treatment of textile wastewater. The Reactive Black 5 dye (RB5) was used as a model dye to evaluate the performance of the model design. The effect of initial solution pH, applied current and treatment time on RB5 removal was investigated. The total number of experiments designed by RSM amounted to 27 runs, including three repeated experimental runs at the central point. The accuracy of the model was evaluated by the F-test, coefficient of determination (R²), adjusted R² and standard deviation. The optimum conditions for RB5 removal were as follows: initial pH of 6.63, current of 0.075 A, electrolyte dose of 0.11 g/L and EC time of 50.3 min. The predicted RB5 removal was 83.3% and the percentage error between experimental and predicted results was only 3-5%. The obtained data confirm that the proposed model can be used for accurate prediction of RB5 removal. The value of the zeta potential increased with treatment time, and the X-ray diffraction pattern shows that iron complexes were found in the sludge.

Declining Mercury Concentrations in Bluefin Tuna Reflect Reduced Emissions to the North Atlantic Ocean

Tunas are apex predators in marine food webs that can accumulate mercury (Hg) to high concentrations and provide more Hg (∼40%) to the U.S population than any other source. We measured Hg concentrations in 1292 Atlantic bluefin tuna (ABFT, Thunnus thynnus) captured in the Northwest Atlantic from 2004 to 2012. ABFT Hg concentrations and variability increased nonlinearly with length, weight, and age, ranging from 0.25 to 3.15 mg kg^-1, and declined significantly at a rate of 0.018 ± 0.003 mg kg^-1 per year or 19% over an 8-year period from the 1990s to the early 2000s. Notably, this decrease parallels comparably reduced anthropogenic Hg emission rates in North America and North Atlantic atmospheric Hg⁰ concentrations during this period, suggesting that recent efforts to decrease atmospheric Hg loading have rapidly propagated up marine food webs to a commercially important species. This is the first evidence to suggest that emission reduction efforts have resulted in lower Hg concentrations in large, long-lived fish.

Methylmercury uptake by diverse marine phytoplankton

Phytoplankton may serve as a key entry for methylmercury (MeHg) into aquatic food webs however very few studies have quantified the bioconcentration of MeHg in marine phytoplankton from seawater, particularly for non-diatoms. Experiments using ²⁰³Hg to measure MeHg uptake rates and concentration factors in six marine phytoplankton species belonging to different algal classes were conducted and the influence of light, temperature, and nutrient conditions on MeHg bioaccumulation were determined. All algal species greatly concentrated MeHg out of seawater, with volume concentration factors (VCFs) ranging from 0.2 × 10⁵ to 6.4 × 10⁶. VCFs were directly related to cellular surface area-to-volume ratios. Most of the cellular MeHg was found in the cytoplasm. Temperature, light, and nutrient additions did not directly affect MeHg uptake in most species, with the exception that the dinoflagellate Prorocentrum minimum displayed significantly greater uptake per cell at 18°C than at 4°C, suggesting an active uptake for this species. Passive transport seemed to be the major pathway for most phytoplankton to acquire MeHg and was related to the surface area-to-volume ratio of algal cells. Environmental conditions that promoted cell growth resulted in more total MeHg associated with cells, but with lower concentrations per unit biomass due to biodilution. The very high bioconcentration of MeHg in marine phytoplankton is by far the largest bioconcentration step in marine food chains and variations in algal uptake may account for differences in the amount of MeHg that ultimately builds up in different marine ecosystems.

Candidate Resonant Tetraneutron State Populated by the ^{4}He(^{8}He,^{8}Be) Reaction

A candidate resonant tetraneutron state is found in the missing-mass spectrum obtained in the double-charge-exchange reaction ^{4}He(^{8}He,^{8}Be) at 186  MeV/u. The energy of the state is 0.83±0.65(stat)±1.25(syst)  MeV above the threshold of four-neutron decay with a significance level of 4.9σ. Utilizing the large positive Q value of the (^{8}He,^{8}Be) reaction, an almost recoilless condition of the four-neutron system was achieved so as to obtain a weakly interacting four-neutron system efficiently.

CNS active target (CAT) for missing mass spectroscopy with intense beams

A new gaseous active target based on a time projection chamber, named CAT, is introduced. The remarkable feature is a dual gain THGEM to decrease the effective gain for the beam particles while keeping a high enough effective gain for the recoil particles. The measured effective gain of low gain region was a factor of one hundred smaller than that of high gain region. This technique provides a wide dynamic range in order to detect both the beam and recoil particles at the same time even with a very high intensity beam of more than 10⁵ Hz.

Gene of the month: PIK3CA

PIK3CA encodes the p110α catalytic subunit of phosphatidylinositol 3-kinase (PI3K) which through its role in the PI3K/Akt pathway is important for the regulation of important cellular functions such as proliferation, metabolism and protein synthesis, angiogenesis and apoptosis. Mutations in PIK3CA are known to be involved in a wide range of human cancers and mutant PIK3CA is thought to act as an oncogene. The specific PIK3CA inhibitor, NVP-BYL719, has displayed promising results in cancer therapy and is currently under clinical trials. Furthermore, PI3K regulates autophagy, a cellular process that recycles proteins and organelles through lysosomal degradation and has recently been recognised as an attractive therapeutic target due to its pro- and anti-cancer properties. Several studies have attempted to investigate the effects of combining the inhibition of both PI3K and autophagy in cancer therapy, and an in vivo model has demonstrated that the combined use of a concomitant PI3K and autophagy inhibitor induced apoptosis in glioma cells.

Enhanced performances in inverted small molecule solar cells by Ag nanoparticles

We demonstrate a highly efficient inverted small molecular solar cell with integration of Ag nanoparticles (NPs) into the devices. The optimized device based on thermal evaporated Ag NPs provides a power conversion efficiency (PCE) of 4.87%, which offers 33% improvement than that of the reference device without Ag NPs. Such a high efficiency is mainly attributed to the improved electrical properties by virtue of the modification of the surface of ITO with Ag NPs and the enhanced light harvesting due to localized surface plasmon resonance (LSPR). The more detail enhanced mechanism of the PCE by introduction of Ag NPs is also discussed.