Controlling organic carbon increase in oxygenated marine sediment by using decarburization slag.

The chemical oxygen demand (COD) in the Seto Inland Sea, Japan has increased in the recent decades due to the increase of bottom dissolved oxygen (DO) concentration which stimulated several autotrophic microorganisms, specially sulfur oxidizing bacteria (SOB). This increased SOB activity due to the oxygenation of the bottom sediment synthesized new organic matter (OM) which contributed dissolved organic carbon to the overlying seawater. This phenomenon further led to hypoxia in some subareas in the Seto Inland Sea. Higher pH or alkaline environment has been found to be an unfavorable condition for SOB. In this research, we used decarburization slag to elevate the pH of sediment to control the SOB activity and consequently reduce OM production in the sediment. Ignition loss of the surface sediment increased from 5.14% 6.38% after 21 days of incubation with aeration; whereas the sediment showed the less ignition loss of 5.71% after 21 days when the slag was incubated in the same experimental setup. Microbial community analysis showed less SOB activity in the slag added aerated sediment which accounts for the controlled increase of OM in the sediment. An additional experiment was conducted with magnesium oxide to confirm whether elevated pH can control the OM increase in sediment due to rising DO. All these results showed that decarburization slag can elevate the pH of the sediment to a certain level which can control the SOB activity followed by controlled increase of OM in the sediment. The findings may be beneficial to control accumulation of sedimentary OM which can act as a source of organic carbon in the overlying seawater.

Impact of eelgrass bed recovery and expansion on phytoplankton growth through nutrient competition.

Eelgrass beds are highly productive and support diverse faunal assemblages; they also take in nutrients from the water and prevent excessive phytoplankton growth in eutrophic coastal waters through the reduction of available nutrients. Despite its importance, the global distribution of eelgrass has declined worldwide. In eutrophic areas with high chlorophyll a (Chl.a) concentrations, natural recovery of eelgrass beds after eutrophication is possible. To facilitate this, sufficient water clarity can be reached after a large enough decrease in phytoplankton concentration. In this study, we proposed a novel indicator for the maximum possible Secchi depth (MPSD), defined as the Secchi depth when the Chl.a concentration is equal to a reference Chl.a concentration. We applied the MPSD to evaluate water clarity improvements through the reduction of terrigenous anthropogenic nutrient loading. We found that phytoplankton did not control water clarity in the study area, which was instead controlled by background factors. Therefore, improvements in water clarity would not be expected after reducing terrigenous anthropogenic nutrient loading. The habitat of Zostera marina is determined by light availability, so we investigated a potential area with ≥20% surface irradiance and Z. marina existed in 27% of it (100 of 373 ha). The maximum further recovery of eelgrass by Secchi depth improvements to the MPSD was estimated at 36 ha. The impact of eelgrass recovery and expansion on phytoplankton growth from May to September was evaluated by a mathematical model under two scenarios: the current eelgrass distribution (100 ha) and potential maximum eelgrass distribution (373 ha). A Chl.a decrease of 1.0-3.0 µg l-1 from 4.0 to 7.0 µg l-1 was achieved in an area from May to July, and the improvement decreased with time. These evaluation methods and findings could help us gain a better understanding of the nutrient management in seagrass-vegetated semi-enclosed seas subjected to anthropogenic nutrient input.

Deterioration Mechanism of a Tertiary Polyamide Reverse Osmosis Membrane by Hypochlorite.

A tertiary polyamide membrane was synthesized using N,N'-dimethyl-m-phenylenediamine. The durability of this membrane to chlorination by hypochlorite treatment followed by sodium hydroxide treatment was examined, and then deterioration mechanisms were proposed. The tertiary polyamide membrane demonstrated better durability to free chlorine than a conventional secondary polyamide one; however, the former was deteriorated by hypochlorite for 24 h at 2000 ppm of free chlorine below pH 7.5. The salt rejection and permeation performance of the membrane were almost unchanged, and the least chlorination of the active layer occurred during hypochlorite treatment at pH 10. These results indicated that hypochlorous acid rather than hypochlorite ion was the free chlorine species that induced membrane deterioration. The deterioration became severe as chlorination progressed, resulting in collapse of the active layer below pH 7.5. Chlorination and hydrolysis of the model tertiary amide N-methylbenzanilide and Fourier transfer infrared spectroscopy of a deteriorated membrane showed that chlorination of the tertiary polyamide occurred via direct chlorination of the benzene bound to the amidic nitrogen. Silver ion probing of the deteriorated membrane revealed that amide bond scission occurred in the active layer, which might be related to the electron deficiency of the amidic nitrogen caused by chlorination of its benzene ring.

Rapid novel test for the determination of biofouling potential on reverse osmosis membranes.

A novel method was proposed to determine biofouling potential by direct analysis of a reverse osmosis (RO) membrane through fluorescence intensity analysis of biofilm formed on the membrane surface, thereby incorporating fouling tendencies of both feedwater and membrane. Evaluation of the biofouling potential on the RO membrane was done by accelerated biofilm formation through soaking of membranes in high biofouling potential waters obtained by adding microorganisms and glucose in test waters. The biofilm formed on the soaked membrane was quantified by fluorescence intensity microplate analysis. The soaking method's capability in detecting biofilm formation was confirmed when percentage coverage obtained through fluorescence microscopy and intensity values exhibited a linear correlation (R(2) = 0.96). Continuous cross-flow experiments confirmed the ability and reliability of the soaking method in giving biofouling potential on RO membranes when a good correlation (R(2) = 0.87) between intensity values of biofilms formed on the membrane during soaking and filtration conditions was obtained. Applicability of the test developed was shown when three commercially available polyamide (PA) RO membranes were assessed for biofouling potential. This new method can also be applied for the determination of biofouling potential in water with more than 3.6 mg L(-1) easily degradable organic carbon.

AMP kinase-related kinase NUAK2 affects tumor growth, migration, and clinical outcome of human melanoma.

The identification of genes that participate in melanomagenesis should suggest strategies for developing therapeutic modalities. We used a public array comparative genomic hybridization (CGH) database and real-time quantitative PCR (qPCR) analyses to identify the AMP kinase (AMPK)-related kinase NUAK2 as a candidate gene for melanomagenesis, and we analyzed its functions in melanoma cells. Our analyses had identified a locus at 1q32 where genomic gain is strongly associated with tumor thickness, and we used real-time qPCR analyses and regression analyses to identify NUAK2 as a candidate gene at that locus. Associations of relapse-free survival and overall survival of 92 primary melanoma patients with NUAK2 expression measured using immunohistochemistry were investigated using Kaplan-Meier curves, log rank tests, and Cox regression models. Knockdown of NUAK2 induces senescence and reduces S-phase, decreases migration, and down-regulates expression of mammalian target of rapamycin (mTOR). In vivo analysis demonstrated that knockdown of NUAK2 suppresses melanoma tumor growth in mice. Survival analysis showed that the risk of relapse is greater in acral melanoma patients with high levels of NUAK2 expression than in acral melanoma patients with low levels of NUAK2 expression (hazard ratio = 3.88; 95% confidence interval = 1.44-10.50; P = 0.0075). These data demonstrate that NUAK2 expression is significantly associated with the oncogenic features of melanoma cells and with the survival of acral melanoma patients. NUAK2 may provide a drug target to suppress melanoma progression. This study further supports the importance of NUAK2 in cancer development and tumor progression, while AMPK has antioncogenic properties.

Chlorophyll and suspended sediment mapping to the Caribbean Sea from rivers in the capital city of the Dominican Republic using ALOS AVNIR-2 data.

This study aims to study the distribution of contaminants in rivers that flow into the Caribbean Sea using chlorophyll-a (Chl-a) and suspended sediment (SS) as markers and ALOS AVNIR-2 satellite sensor data. The Haina River (HN) and Ozama and Isabela Rivers (OZ-IS) that flow through the city of Santo Domingo, the capital of the Dominican Republic, were chosen. First, in situ spectral reflectance/Chl-a and SS datasets obtained from these rivers were acquired in March 2011 (case A: with no rain influence) and June 2011 (case B: with rain influence), and the estimation algorithm of Chl-a and SS using AVNIR-2 data was developed from the datasets. Moreover, the developed algorithm was applied to AVNIR-2 data in November 2010 for case A and August 2010 for case B. Results revealed that for Chl-a and SS estimations under cases A and B conditions, the reflectance ratio of AVNIR-2 band 4 and band 3 (AV4/AV3) and the reflectance of AVNIR-2 band 4 (AV4) were effective. The Chl-a and SS mapping results obtained using AVNIR-2 data corresponded with the field survey results. Finally, an outline of the distribution of contaminants at the mouth of the river that flows into the Caribbean Sea was obtained for both rivers in cases A and B.

Responses of the benthic environment to reduction in anthropogenic nutrient loading in the Seto Inland Sea (Japan), based on M-AMBI assessment.

Deterioration of the sediment environment and benthic ecosystem is an undesirable effect of eutrophication, but little is known about the response of macrobenthic communities to eutrophication and their long-term recovery. In the present study, temporal changes in benthic ecological status, associated with reductions in anthropogenic impacts on a largest semi-enclosed sea in Japan, were determined using long-term monitoring data from water and sediment quality based on the multivariate AZTI Marine Biotic Index (M-AMBI), focusing on spatial differences in anthropogenic impacts. Several sub-areas were classified based on Chlorophyll a (Chl.a) concentrations in surface water during the 1980s. Chl.a concentrations decreased in all sub-areas except the sub-area with <2 µg Chl.a L-1 from the 1990s-2010s. On the other hand, total organic carbon contents in sediment decreased and M-AMBI values increased in all sub-areas during this period may be due to reduced lateral organic matter advection from surrounding areas.

Effect of fine bubbles for washing of monolith type porous ceramic membranes treating oil-in-water emulsions.

Produced water generated in the recovery of crude oil contains oil and high concentrations of salts, organic matter, and suspended solids and must therefore be treated appropriately prior to disposal. Monolithic ceramic membranes have high oil removal rates and have the advantage of being compact, having a long life, and withstanding chemicals, heat, and high cleaning pressures. Membrane fouling, however, is a significant drawback to membrane filtration. Scrubbing using air bubbles generated by a diffuser is generally used to physically clean membranes. However, monolithic ceramic membranes cannot be scrubbed using air bubbles because their fluid channels are only a few millimeters wide. Membrane washing efficiency was therefore evaluated using fine bubbles smaller than the diameter of the channels. In dead-end filtration, flushing the membrane surface with air-microbubble water or air-ultra-fine bubble (UFB) water after backwashing and air-blowing (conventional cleaning) of the channels was more efficient than conventional cleaning. Flushing with UFB water was not influenced by changes in pH that changed the zeta potential of the UFB. Membrane fouling was suppressed in crossflow filtration by mixing UFB water with feed water. There was no significant change in the diameter of the oil droplets in the feed water before and after UFB mixing. The ZP of the oil droplets peaked at around -20 mV before UFB mixing. However, the peak shifted to around -25 to -29 mV after UFB mixing.

Utility of Concurrent Surgical Treatment Strategy with Thoracoscopic Esophagectomy for Patients with Synchronous Esophageal and Head and Neck Cancer.

Background: Patients with esophageal squamous cell cancer (ESCC) have a high frequency to coincide with head and neck cancer (HNC). This study aims to analyze the treatment results and prognosis of patients with synchronous ESCC and HNC. Methods: From January 2016 to December 2019, 5 patients underwent concurrent surgical resection of synchronous ESCC and HNC in our institution. We retrospectively reviewed the surgical outcomes and prognosis of these patients with synchronous ESCC and HNC (HNEC group) and compared the results with those of 20 patients who underwent esophagectomy with three regional lymph node dissections for ESCC during the same period (EC group). Results: The locations of HNCs were pharynx/tongue (4/1) and the clinical stages were Stage IV in all patients. Meanwhile, the clinical stages of ESCCs were Stages 0/I/II/III (1/1/2/1). All patients underwent thoracoscopic esophagectomy. The surgical procedures concurrently performed for HNC were pharyngolaryngectomy with free jejunum transfer in 3 patients, wide tongue and mandibular segment resection with mandibular reconstruction in 1 patient, and mandibular transection with radial forearm flap reconstruction in 1 patient. There was no significant difference in the frequency of postoperative complication between these two groups. The HNEC group had a significantly shorter recurrence-free survival than the EC group (P = .046). Conclusion: Head and neck surgery with thoracoscopic esophagectomy can be safely performed concurrently with local control. The risk of recurrence is higher in ESCC patients with HNC; therefore, it is important to move on to adjuvant therapy without delay.

A quantitative analysis method to determine the amount of cellulose fibre in waste sludge.

A novel quantitative analysis method for cellulose fibre was developed to understand its behaviour in biological wastewater treatment and waste sludge processes. The method developed in this study was designed using Pseudomonas aeruginosa to remove it by dissolving all the organic components except cellulose from the sludge due to needing the solubilisation of bacteria occupied almost of sludge matrix and quantifying the amount of remaining cellulose. The results of this study indicated that a combined treatment process that employed 2,000 U/L protease, 2 M hydrogen peroxide, and 2 mM potassium hydroxide after pre-treatment for floc dispersion with an ultrasonic treatment at 26 W for 1 min resulted in a solubilisation of 96% of P. aeruginosa without losing the cellulose fibre. When it was applied to the cellulose fibre added in the sludge from a municipal wastewater treatment facility, 99.5% of the cellulose fibre was recovered by using the high-speed centrifuge.

Reduction of ozone dosage by using ozone in ultrafine bubbles to reduce sludge volume.

Sludge ozonation, which promotes sludge disintegration and solubilization, is a promising technology for reducing waste sludge volume from biological wastewater treatment process. However, if this technology is to be widely adopted, reducing the energy consumption associated with ozone generation will be necessary. We used ultra-fine bubbles (UFBs) as ozone carriers to determine if their use could improve the efficiency of ozone treatment and reduce the ozone dose required. We used a spiral, liquid-type UFB generator, which can introduce UFBs directly into a sludge suspension. The death ratio of bacteria in sludge was used as an indicator of sludge reduction. The ozone requirement was reduced by UFBs. The ozone consumption required to achieve a death ratio of 80% was 15 mg-O3/g-MLSS in the sludge treated with ozone supplied by UFBs versus 25 and 45 mg-O3/g-MLSS in sludges treated with ozone supplied as a spiral, liquid-type microbubbles and by a diffuser, respectively. When mixing water ozonated with UFBs with sludge, the depth of the dead cell layer from the surface to the interior of the sludge floc was larger than that of ozonated water lacking UFBs at the same rate of ozone consumption. Ozone in UFBs kills bacteria inside the flocs. However, the fragmentation of sludge flocs by shear forces in the UFB generator made a larger contribution to the acceleration of bacterial death in sludge treated with ozone supplied by UFBs.

Increase in sedimentary organic carbon with a change from hypoxic to oxic conditions.

In the Seto Inland Sea, Japan, chemical oxygen demand has increased over recent decades, while average dissolved oxygen concentrations in the bottom water have increased. In this study, we investigated responses of organic carbon (OC) in hypoxic sediment to changes of redox conditions using experimental columns containing sediment and overlying water. Surface sediment showed an increase in OC along with the change to an aerobic condition. Microbial community analysis showed a predominance of sulfur-oxidizing bacteria (SOB) such as Sulfurovum sp. in the sediment. This dominance could account for the increased OC. Additionally, the dissolved organic carbon (DOC) concentration in the overlying water increased. Further experiments using sandy sediment showed that biodegradation of Sulfurimonas denitrificans was associated with DOC release. These results show that a change in the sedimentary environment (increase in dissolved oxygen) increased the sedimentary OC and DOC of overlying water by stimulating certain autotrophic bacteria, especially the SOB.

Phase I/II study of s-1 plus cisplatin combination chemotherapy in patients with advanced/recurrent head and neck cancer.

OBJECTIVE: The objectives of this study were to determine the maximum tolerated dose (MTD) and recommended dose (RD) of S-1 plus cisplatin (CDDP) and to evaluate safety and efficacy using the defined RD in advanced/recurrent head and neck cancer (HNC). METHODS: S-1 was administered orally at 40 mg/m(2) twice daily for 14 consecutive days, and CDDP was infused on day 8 at a dose of 60 and 70 mg/m(2). Each course was repeated every 4 weeks. RESULTS: A total of 38 patients were registered, 10 patients for the Phase I study and an additional 28 patients for the Phase II study. Although no dose-limiting toxicity (DLT) was observed in the CDDP 60 mg/m(2) (Level 1) group, two of six patients in the CDDP 70 mg/m(2) (Level 2) group exhibited DLT (fatigue/diarrhea). The MTD was not achieved in the Phase I study. Level 2 was therefore determined as the RD. In the Phase II study, 34 patients, including 6 patients from the Phase I study, were evaluated. At the termination of treatment, the confirmed response rate was 44.1% (15/34, 95% CI: 27.4-60.8). The best response rate without an adequate duration time was 67.6% (95% CI: 51.9-83.4). The median survival period was 16.7 months, and the 1-year survival rate was 60.1%. The main toxicities of Grade 3 or above were anorexia (26.5%), nausea (14.7%), neutropenia/thrombocytopenia (11.8%) and anemia/fatigue (8.8%). CONCLUSIONS: This is considered to be an effective regimen with acceptable toxicities for HNC.

Application of Aurantiochytrium sp. L3W for food-processing wastewater treatment in combination with polyunsaturated fatty acids production for fish aquaculture.

Thraustochytrids such as Aurantiochytrium are heterotrophic microorganisms that are known to produce valuable polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). In this study, Aurantiochytrium sp. strain L3W was used to remove dissolved organic carbon (DOC) and dissolved nitrogen (DN) from bean-boiling (BB) and miso-processing (MP) wastewater and to simultaneously produce PUFAs. Strain L3W removed 52% of the DOC and 37% of the DN from sterilized BB wastewater and produced biomass that contained 137 mg/g of fatty acids (FAs), including 96.2 mg/g of DHA. Growth of strain L3W in sterilized MP wastewater resulted in the production of biomass containing 147.6 mg/g of FAs, including 97.8 mg/g of DHA, and removal of 47% of the DOC and 55% of the DN from the wastewater. The biomass of strain L3W was digestible by the enzymes extracted from the stomachs of rainbow trout. These results confirmed the potential for use of strain L3W to remove DOC and DN from food processing wastewater and to produce PUFAs. This study also provided the first evidence that the raw biomass of Aurantiochytrium sp. can be used as a fish feed additive.

Benthic quality assessment using M-AMBI in the Seto Inland Sea, Japan.

Benthic invertebrates that inhabit the seafloor respond to anthropogenic and natural stresses, and are good indicators for assessing the benthic ecological status. We evaluated the ecosystem health of the Seto Inland Sea based on the multivariate AZTI Marine Biotic Index (M-AMBI), being its first application in a Japanese coastal sea with numerous endemic species. From the 415 locations studied, we were able to use M-AMBI in 384 sites (92.5% in all sites). The result revealed a statistically significant correlation among biotic indices including AMBI, M-AMBI, Richness, and H' (p < 0.01). Most of the physico-chemical parameters of the sediment (water content, total organic carbon (TOC) content, sulfide content, mud content, and oxidation-reduction potential (ORP)) were significantly correlated with each other excluding sediment temperature. The M-AMBI was significantly correlated with physico-chemical variables including water content, TOC content, sulfide content, and ORP. We found that the sites classified into the organically enriched cluster, and having high contents of TOC, mud, and sulfide and negative ORP, corresponded with sites that had significantly low M-AMBI values (bad-poor ecological status). Conversely, sites in the unpolluted sandy cluster were assigned high M-AMBI values (high-good ecological status). Therefore, M-AMBI would be a useful biotic index in Japanese coasts due to the representation of the comprehensive sediment quality.

Ozonation of trichloroethylene in acetic acid solution with soluble and solid humic acid.

The combined flushing and oxidation process using acetic acid and ozone has been used successfully to remove trichloroethylene (TCE) completely from contaminated soil. In this study, the effects of humic acid, a fraction of the organic matter in soil, over the performance of TCE decomposition was evaluated. TCE decomposition by ozone was enhanced by the presence of humic acid at concentrations lower than 8mgCL(-1) and then inhibited at higher concentrations. It is possible that the presence of the soluble humic acid fraction during the ozonation of TCE in acetic acid solutions produces hydroxyl radicals during the TCE ozonation which appears to be the reason for the enhanced TCE decomposition rate. Solid humic acid reduced TCE decomposition rate by acting as an ozone scavenger. Similarly, sorbed TCE reduced the amount of TCE available for decomposition by ozone in solution.

Benthic ecosystem development in an artificial tidal flat constructed from dredged spoil.

Dredged spoil (DS) was used as a silt and clay additive in the construction of artificial tidal flats from mountain sand (MS). As the ratio of DS in the sediment media increased, the number of emerging macrobenthos increased. The composition of the macrobenthic community was also affected by the addition of DS, and the changes might be dependent on the ratio of DS to MS. In addition, the macrobenthos in the artificial tidal flats was more abundant than that in the control tidal flat, which was constructed with natural tidal flat sediment. With a silt and clay content of 25%, polychaetes Ceratonereis erythraeensis and Capitella sp. and the gastropod Batillaria cumingii were dominant, whereas no bivalves were present. With less silt and clay (5% and 10%), the bivalves Ruditapes philippinarum and Musculista senhousia were observed in the artificial flats, while their numbers in the control tidal flat were lower.

Effect of ozonated water on the surface roughness of dental stone casts.

Infection control of dental stone cast is an important issue. Ozone is effective for disinfection against microorganisms and inactivation of viruses. However, there is little information regarding the use of ozone. We prepared 4 types of gypsum specimens and 3 types of disinfectants (4-5 ppm Ozonated water [OZW], 2% glutaraldehyde [GL], and 1% sodium hypochlorite [SH]). Gypsum specimens were immersed in each disinfectant for 5 and 10 min, and surface roughness was then examined using laser scanning microscopy. Surface microstructure was investigated using scanning electron microscopy. Immersion of gypsum specimens in SH, GL, and OZW increased the surface roughness to a maximum of 1.04, 0.37, and 0.30 µm, respectively, based on the difference between the average values of surface roughness before and after the disinfection procedure. The effects of OZW and GL were comparable. OZW is useful as a candidate for relatively safe disinfection of material for dental stone casts.

Spatial distribution of hydrogen sulfide and sulfur species in coastal marine sediments Hiroshima Bay, Japan.

This study aims to reveal spatial distribution of hydrogen sulfide and sulfur species in marine sediments in Hiroshima Bay, Japan, by direct analyses using a combination of detection tubes and X-ray absorption fine structure spectroscopy. In summer and autumn, the hydrogen sulfide concentration ranged from <0.1 to 4 mg-S L-1. In this study, only hydrogen sulfide was observed in autumn and at two stations in summer. In contrast, some earlier studies reported in all seasons in Hiroshima Bay the presence of acid volatile sulfide, which is used as a proxy of sulfide content. The sulfur species in sediments were mainly identified as sulfate, thiosulfate, elemental sulfur, and pyrite. Thiosulfate was a minor component compared to the other sulfur species. The formation of pyrite and sulfur derived from hydrogen sulfide oxidation played an important role in the scavenging of hydrogen sulfide.

Enhancement of biodegradation of oil adsorbed on fine soils in a bioslurry reactor.

Techniques for enhancing the biodegradation of oil-contaminated fine soils in a slurry-phase bioreactor were investigated. Using a model system consisting of kaolin particles containing adsorbed n-dodecane as a diesel fuel surrogate, we investigated how increasing the temperature and adding a surfactant and various hydrophobic support media affected the biodegradation rate of n-dodecane. Increasing the temperature from 25 to 35 degrees C decreased the time required for complete degradation of n-dodecane by 30%, from 110h to 80h. Addition of the surfactant polyethylene glycol p-1,1,3,3-tetramethylbutylphenyl ether decreased the degradation time to less than 48h at 35 degrees C, although a high concentration of the surfactant (3000mgl(-1)) was required. We suspect that the surfactant increased the degradation rate by solubilizing the n-dodecane into the solution phase in which the microorganisms were suspended. We tested five types of organic polymers as support media for the microorganisms and found that the biodegradation time could be reduced by approximately 50% with a support medium made from polyurethane; in the presence of this medium, only 36h was required for complete decomposition at 35 degrees C. The reduction in the degradation time was probably due to transfer of the n-dodecane from the soil to the support medium, which improved contact between the n-dodecane and the microorganisms. The polyurethane support medium bearing the microorganisms was stable and could be reused.