2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD)-induced down-regulation of glucose transporting activities in mouse 3T3-L1 preadipocyte

The possibility that 3T3-L1 preadipocytes, while the level of its glucose uptake activity is relatively low, may offer a useful tool for studying the cause for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced "lipolytic response" was studied. It was established first, that TCDD causes reduction of glucose uptake, one of the hallmark events of the lipolytic process. Then the function of c-Src was investigated. The antisense c-src oligonucleotide decreased the inhibitory action of TCDD on glucose uptake activity in a sequence specific manner. Since antisense oligonucleotides are known to own their blocking effects to their ability to reduce translation of proteins, Western blotting analysis was performed to verify their effectiveness. As expected, the treatment of pre-adipocytes with antisense c-src oligonucleotide reduced c-Src in a sequence specific manner. The treatment of antisense c-src oligonucleotide alone was sufficient to diminish the inhibitory action of TCDD on glucose uptake activity in 3T3-L1 cells, indicating that c-Src is somehow involved in the action of TCDD. In a similar manner, the contribution of c-Fos was investigated using antisense c-fos oligonucleotide, since c-Fos is known to be one of the most affected proteins by c-Src activation among AP-1 members. The treatment of antisense c-fos oligonucleotide did not block the effect of TCDD on glucose uptake activity in 3T3-L1 cells. Therefore, it is unlikely that c-Fos is very important in the lipolytic signal transduction of TCDD mediated through c-Src. In order to determine the relationship between c-Src and c-Myc in the mitotic signal transduction pathway, the effect of antisense c-myc oligonucleotide was investigated. Basically the same result as antisense c-src oligonucleotide experiment was obtained thereby, suggesting the importance of c-Myc as well as c-Src in the signal transduction of TCDD. To show the effect of antisense c-myc oligonucleotide treatment, the level of c-Myc protein by Western blotting and electrophoretic gel-mobility shift assay was assessed. However, antisense c-myc oligonucleotide treatment increased the activity of c-Myc in a sequence specific manner. This may be the result of cellular compensatory response to the initial suppression of c-Myc by antisense treatment. The observation that antisense c-fos oligonucleotide could not block the effect of TCDD indicates that this preadipocyte model is different from the adipocyte differentiation model.     

Relation between mechanochemical dechlorination rate of polyvinyl chloride and mill power consumption

A sample of polyvinyl chloride (PVC) powder was milled with CaO powder in a planetary mill for various mill operational parameters. The milled product consisted of dechlorinated hydrocarbon and water-soluble CaOHCl. The dechlorination rate of PVC was determined by the concentration of Cl⁻ ions measured in solution after dispersing the milled product in water. To evaluate the power consumption during PVC dechlorination, the mill power consumption was measured during each experimental run. In addition, media motion during planetary milling was simulated using the discrete element method (DEM), enabling calculation of the mill power consumption. The power consumption calculated by the DEM simulation compared well with the power consumption measured experimentally. The dechlorination rate correlated well with the specific mill power consumption, regardless of the sample weight. The dechlorination rate of PVC when milled with oyster shells (CaCO₃) was observed to be faster than that of the PVC/CaO system, and oyster shells could be used as a reactant for the treatment of PVC wastes. This work should be useful for the design of a reactor for the dechlorination of PVC. Chemical Feedstock Recycling & Other Innovative Recycling Techniques 6     

Deplasticization and dechlorination of flexible polyvinyl chloride in NaOH solution by microwave heating

This study investigated the deplasticization and dechlorination of flexible polyvinyl chloride (PVC) containing 59.2% PVC, 29.7% dioctyl phthalate (DOP), and approximately 12% stabilizers. Flexible PVC was treated with NaOH solutions at concentrations in the range 2–16 mol/l and heated by microwaves to temperatures between 100° and 250°C for 0–120 min. DOP was extracted from flexible PVC into the NaOH solution as a phthalic acid salt; the remaining PVC was subsequently dechlorinated by increasing the temperature. On internal heating using microwaves, the plasticizer was 100% extracted during processing at 150°C for 30 min, whereas the chlorides were 100% removed during processing at 235°C for 30 min; the residue was converted into hydrocarbon compounds. The maximum weight loss ratio was 71% compared to the pretreatment state. It was also found that 100% deplasticization and dechlorination was possible using 8 mol/l NaOH solution, which is almost half the concentration employed when using conventional external heating systems.     

Di(2-ethylhexyl)phthalate and mono(2-ethylhexyl)phthalate in media for in vitro fertilization

In vitro fertilization (IVF) is one of the most important treatments of infertility to provide a chance of conceiving. In IVF treatment, sperm are washed and motile sperm are isolated with sperm washing media (SWM) for the purpose of fertilization; fertilized ova are then incubated for a maximum of 5 or 6 d in media for IVF (IVFM). The exposure of fertilized ova to chemicals via such media has not been studied. We determined the concentrations of two contaminants; di(2-ethylhexyl)phthalate (DEHP) and its hydrolyzed product mono(2-ethylhexyl)phthalate (MEHP) in IVFM, SWM, and protein sources (PS: human serum albumin or serum substitute) for IVFM and SWM. The DEHP and MEHP in these media were extracted by a liquid-liquid extraction method and their concentrations determined by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Fifteen IVFM, nine SWM, and six PS obtained in Japan were examined. The concentrations of DEHP and MEHP in IVFM and SWM were <10-114 and <2.0-263 ng mL⁻¹, respectively. The concentrations of both DEHP and MEHP were higher in the media containing PS than in those without PS. Either MEHP alone or both DEHP and MEHP were detected in PS. The concentrations of DEHP and MEHP in PS were <10-982 and 47.0-1840 ng mL⁻¹, respectively. The DEHP and MEHP detected in these media were derived from PS. This is the first study on the chemical contamination of IVFM, SWM, and PS.     

Developments in an industry-led R&D program for recycling PVC products in Japan

To facilitate recycling, not only R&D but also the creation of efficient recycling systems—collection and processing of recyclates as well as finding appropriate end-uses—is essentially important. PVC has a particular advantage in regards to mechanical recycling when compared to other major plastics. However, there is no one-size-fits-all approach to a solution. Specific situations of used or off-cut products and their applications need to be well studied. Vinyl industry in Japan has devoted itself for many years to the promotion of recycling of vinyl products. It started an R&D support program in 2007 and seven projects have been completed since then. Some of the new developments include mechanical recycling for products like wall covering and tarpaulin which were considered difficult to recycle in the past. Progress in chemical recycling has been made with a technology for the removal of chlorine from shredder dusts. Recovery of chlorine is a challenge for the future. Collaboration among the various players involved in the recycling of a specific product is essential for obtaining a successful result.     

Evaluation of aquatic environmental fate of 2,4,6-trichlorophenol with a mathematical model

A mathematical model, Simplified Approach for Fate Evaluation of Chemicals in Aquatic Systems (SAFECAS), was applied to evaluate fate of 2,4,6-trichlorophenol(TCP) in three types of aquatic environments; a river, an oligotrophic lake, and an eutrophic lake.Since phenols are dissociative substances, equilibrium constants and rate constants for transfer and transformation processes were measured or estimated as a function of pH.Results suggest that most of TCP is distributed to the water phase in aquatic environments, and is almost removed by the advective outflow in the river and by the photodegradation in lakes.     

Carbon Sequestration by Carbonization of Biomass and Forestation: Three Case Studies

We proposed the carbon sink project called “Carbon Sequestration by Forestation and Carbonization (CFC),” which involves biomass utilization and land conservation by incorporating the products of biomass carbonization into the agents for soil improvement, water purification, etc. Our purpose was to demonstrate the potential of the CFC scheme for carbon sequestration, particularly carbon storage in soil. Case studies were conducted in both developing and developed countries. 1. In southern Sumatra, Indonesia, 88,369 Mg-C year⁻¹ of wood residue from a plantation forest and excess bark from a pulp mill would be converted into 15,571 Mg-C year⁻¹ of the net carbon sink by biochar for soil improvement. The fixed carbon recovery of the system is 21.0%. 2. In a semiarid region in western Australia, the carbonization of wood residue was incorporated with multipurpose projects of a mallee eucalyptus plantation that involved the function of salinity prevention. During the project period of 35 years, the total carbon sink would reach 1,035,450 Mg-C with 14.0% by aboveground biomass, 33.1% by belowground biomass and 52.8% by biochar in soil. 3. In southern Kyushu, Japan, the study was focused on the effective use of surplus heat from a garbage incinerator for carbonizing woody materials. Sawdust of 936.0 Mg-C year⁻¹ would be converted into the net carbon sink of 298.5 Mg-C year⁻¹ by carbonization, with the fixed carbon recovery of the system being 31.9%. Consequently, the CFC project could encourage the creation of a carbon sink in soil. However, we recognize that the quality standard of biochar, the stability of biochar in soil, and the methods for monitoring biochar utilization must be clarified before incorporating biochar carbon into the carbon credit system. Throughout this article (except for diagrams and in citation details) carbonized biomass is, with the authors'agreement, called ‘biochar’ in lieu of the commonly used but misleading word ‘charcoal’ (Editor).     

Effect of additives on dechlorination of PVC by mechanochemical treatment

Polyvinyl chloride (–CH₂–CHCl–) _n (PVC) was ground with a powdered inorganic material (CaO, CaCO₃, SiO₂, Al₂O₃, or slag) in a planetary ball mill under atmospheric conditions to investigate the effect of additions on its dechlorination. The grinding causes a dehydrochlorinating reaction, forming a mixture of partially dechlorinated PVC and inorganic chloride, depending on the grinding time. The dechlorination increases as the grinding progresses, and is improved with increasing amounts of additives. The most effective additive is a mixture of CaO, SiO₂, and Al₂O₃, which has the same constituent components as blast furnace slag. CaO, a mixture of CaO, SiO₂, and blast furnace slag, are also effective, but CaCO₃ is the least effective additive tired. Received: August 3, 2000 / Accepted: September 21, 2000     

Multi‐phase non‐steady state equilibrium model for evaluation of environmental fate of organic chemicals

A simple mathematical fate model, Multi‐Phase Non‐Steady State Equilibrium Model (MNSEM) is proposed to evaluate distribution, persistence, and concentrations of chemicals in a model environment consisting of air, water, soil and sediment phases. The model is applied to evaluation of environmental fate and concentration of trichloroethylene and 1,4‐dichlorobenzene under generic conditions representative of Japan.

Evaluated chemical concentrations in air are within a factor of 3 of average values in Japanese atmosphere, and evaluated concentrations in water, sediment, or fish are greater than an order of magnitude below detection limits in real environments, so that evaluated concentrations are in reasonable agreement with environmental measurement data in Japan.

Although MNSEM is not a model for site‐specific evaluation of environmental fate, results suggested that this model is an adequate method to aid in evaluation of fate of chemicals under generic environment conditions. Evaluated concentration‐profiles may be used to estimate average chemical exposure concentrations for humans and the environment.     

Heat and carbon dioxide generated by honeybees jointly act to kill hornets

We have found that giant hornets (Vespa mandarinia japonica) are killed in less than 10 min when they are trapped in a bee ball created by the Japanese honeybees Apis cerana japonica, but their death cannot be solely accounted for by the elevated temperature in the bee ball. In controlled experiments, hornets can survive for 10 min at the temperature up to 47°C, whereas the temperature inside the bee balls does not rise higher than 45.9°C. We have found here that the CO₂ concentration inside the bee ball also reaches a maximum (3.6 ± 0.2%) in the initial 0–5 min phase after bee ball formation. The lethal temperature of the hornet (45–46°C) under conditions of CO₂ concentration (3.7 ± 0.44%) produced using human expiratory air is almost the same as that in the bee ball. The lethal temperature of the honeybee is 50–51°C under the same air conditions. We concluded that CO₂ produced inside the bee ball by honeybees is a major factor together with the temperature involved in defense against giant hornets.