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In this study, we developed a polystyrene-platinum/nitrogen-doped titanium dioxide/strontium titanate composite-polyvinylpyrrolidone (PS-PNS-PVP) photocatalyst film, which is applied in the process of photocatalytic hydrolysis under simulated sunlight to produce hydrogen, is developed. PS, which is cheap, non-toxic, with high UV resistance, and chemical inertness, is used as a carrier, and a highly effective hydrogen production of Pt/N–TiO2/SrTiO3 as a photocatalyst. The influence of the PS concentration on the stability, optical, and electrical properties of the photocatalyst film is discussed. In addition, the influence of the photocatalyst dispersion in the film on the activity under various photocatalyst concentrations was investigated. A polyvinylpyrrolidone pore-forming agent was then used to examine the effect on the photocatalyst film structure and optical properties, and the subsequent influence on photocatalytic hydrogen energy activity. Adjusting the PS concentration to 20 wt% produced good film-forming stability, and the photocatalyst dispersibility in the film under different photocatalyst concentrations. A photocatalyst concentration of 2.5 wt% resulted in good film dispersibility and the realization of added pore-forming agent. The modified photocatalyst film changed the film from a blind pore structure to a connecting void structure, increasing the film's porosity and hydrophilicity. This increased the number of photocatalytic sites, and the optimal hydrogen production of the photocatalyst film reached 21,333 μmol h−1 g−1.

Proving the device performance and process feasibility is imperative for the realization of two-dimensional (2D) semiconductor electronics. In this work, we have successfully adopted Tin (Sn) as the Ohmic contact metal to monolayer molybdenum disulfide (MoS2) grown by chemical vapor deposition (CVD) and demonstrated superior short channel n-type field effect transistor (nFET) performance reaching an ON-current of $480~\mu \text{A}/\mu \text{m}$ and keeping the OFF-current below 0.1 nA/ $\mu \text{m}$ at $\text{V}_{DS} = 1$ V. These efforts are close to the low power specification of Si transistors in the metrics of International Roadmap for Devices and Systems (IRDS). The performance improvement could be attributed to the re-melting behavior of Sn metal. We suggest that the Sn deposited at lower temperatures could reduce the formation of interfacial defects caused by heat, and high-melting-point capping metal also could assist the re-melting phenomenon of underlying Sn contact layer. These process modifications are helpful to form smooth Sn coverage on MoS2, thereby reducing the contact resistance to 0.84 $\text{k}\Omega \cdot \mu \text{m}$ . This work provides a practical pathway to form low-resistance metal contact on 2D semiconductors for performance improvement.

We study the characteristics of graphene grown through low power capacitive coupled radio frequency plasma enhanced chemical vapor deposition (PECVD) and explore its application. Fully-covered, mostly single-layered, and highly defective graphene films were grown on Cu substrates through plasma composed of various argon/methane/hydrogen gas ratio with low RF power within a minute under a moderate substrate temperature at 850 °C . The structural, chemical, and electrical properties of the graphene films were measured through Raman spectroscopy, X-ray photoelectron spectroscopy, and Hall measurement, respectively. The Raman signatures were strongly affected by the argon/hydrogen flow rates and the subsequent thermal annealing, and is strongly correlated to carrier mobility of the film. Through analysis of the defect related Raman bands within the theoretical framework of activated defect model, it is concluded that the defects found in the graphene films are originated from ion bombardment during the growth processes. The vacancy defects on the graphene film provides adsorption sites for gaseous molecules and induces changes of charge transfer in the graphene film. The response of the graphene-based sensor fabricated with the PECVD grown graphene is 6% under 100 ppb of N O 2 , which can be a candidate of potential N O 2 gas sensing material in the future.

In this study, a farmland contaminated by heavy metals (Cu, Zn, Ni, and Cr) was selected to evaluate the performance of poly-γ-glutamic acid (γ-PGA) on the removal of heavy metals in soil washing. The highest heavy metal concentrations at the contaminated site were Cu: 1180 mg/kg, Zn: 1450 mg/kg, Ni: 287 mg/kg, and Cr: 316 mg/kg. Batch experiments designed by Taguchi Method were conducted first to assess the effect of different washing conditions on the removal of heavy metals in laboratory. The results of batch experiments show that factors that affected the removal efficiency of heavy metals was of the order γ-PGA concentration > washing time > liquid/soil ratio > rotational speed. The optimal operating parameters for heavy metal removal were γ-PGA 3.5%, liquid/soil ratio 15/1, washing time 60 min, and rotational speed 100 rpm. Under the optimal conditions, up to 50.7% of the major target metal, Cu, was removed. Heavy metals in the soil were mainly Fe-Mn oxide bound and organically bound. On-site treatment using the optimal operating parameters caused 54.3% of Cu removal. When the soil was washed 3 times by γ-PGA, the removal efficiency of Cu was improved to 74.3%. After the treatment, the change in soil bacterial number was insignificant, indicating that γ-PGA is an environmentally friendly washing reagent.

We present the study on graphene growth on Cu substrate through low power capacitive coupled radio frequency (RF) plasma enhanced chemical vapor deposition. Fully-covered graphene was grown on Cu substrate through a plasma composed of various argon/methane/hydrogen gas ratio with a 50 W RF power source within a minute under a relatively low substrate temperature at 850 ∘C. The nucleation and growth dynamics is further investigated through processing and analysis of the images acquired through scanning electron microscopy, and interpreted with a modified Johnson-Mehl-Avrami-Kolmogorov model. The roles of hydrogen in limiting the nucleation density and stabilization of the graphene grain edges are discussed in light of the analysis, and a time dependent grain expansion rate in which the graphene grains grow fast at the early stage and saturated at later stage is implemented into the model to achieve good fitting of the coverage evolution.

Adsorbent made by carbonization of biomass under oxygen-limited conditions has become a promising material for wastewater treatment owing to its cost-effective, simple, and eco-friendly processing method. Ultrasound is considered a green technique to modify carbon materials because it uses water as the solvent. In this study, a comparison of Reactive Black 5 (RB5) adsorption capacity between biochar (BC) generated by pyrolysis of water bamboo (Zizania latifolia) husks at 600 °C and ultrasound-assisted biochar (UBC) produced by pyrolysis at 600 °C assisted by ultrasonic irradiation was performed. UBC showed a greater reaction rate and reached about 80% removal efficiency after 4 h, while it took 24 h for BC to reach that level. Scanning electron microscope (SEM) images indicated that the UBC morphology surface was more porous, with the structure of the combination of denser mesopores enhancing physiochemical properties of UBC. By Brunauer, Emmett, and Teller (BET), the specific surface areas of adsorbent materials were analyzed, and the surface areas of BC and UBC were 56.296 m2/g and 141.213 m2/g, respectively. Moreover, the pore volume of UBC was 0.039 cm3/g, which was higher than that of BC at 0.013 cm3/g. The adsorption isotherms and kinetics revealed the better fits of reactions to Langmuir isotherm and pseudo-second-order kinetic model, indicating the inclination towards monolayer adsorption and chemisorption of RB5 on water bamboo husk-based UBC.

The fission and fusion processes determine mitochondrial morphology and function, in which signaling lipids play pivotal roles. Phosphatidic acid (PA) generated by PLD6, a mitochondrial phospholipase D, is essential for mitochondrial fusion; however, the underlying mechanism is still unclear. We previously discovered that a nucleoside diphosphate kinase, NME3, is critical for mitochondrial fusion yet through a kinase-independent activity. Here we demonstrate that NME3 functions as a mitochondrial tethering factor through binding to PA with its N-terminal amphipathic helix, enriching at the tip of mitochondria, and clustering membranes via its oligomeric structure. Optogenetic induction of PLD activity enhances NME3 recruitment to mitochondria in a catalytic-dependent manner, and NME3 is required for PLD6-mediated mitochondrial fusion. Together, PLD6-generated PA on mitochondria promotes NME3 binding, thereby increasing mitochondrial tethering to facilitate membrane fusion.

Background. Type 1 diabetes mellitus (T1DM) causes the irreversible destruction of pancreatic beta cells. The Bacillus Calmette–Guerin (BCG) vaccine can modulate the immune response and decelerate disease progression. The aim of this study is to investigate the efficacy of the BCG vaccine for the treatment of T1DM. Objective. Six databases were systematically searched from inception to the end of August 2019. The randomized controlled trials (RCTs) that evaluated glycemic control in response to the BCG vaccine for T1DM were enrolled. The primary outcome was glycated hemoglobin (HbA1c) level, and secondary outcomes included fasting and stimulated C-peptide level, daily insulin dosage, and clinical remission. The revised Cochrane risk of bias tool was used for quality assessment, and meta-analyses were conducted to evaluate the efficacy of the BCG vaccine. Results. Four studies with a total of 198 subjects were included. The results of HbA1c and fasting C-peptide levels were extracted for further quantitative assessment. The pooled meta-analysis demonstrated no significant difference in HbA1c levels (mean difference [MD], −0.12; 95% confidence interval [CI], −0.53 to 0.30; I2=56%) or fasting C-peptide levels (MD, −0.15; 95% CI, −0.35 to 0.06; I2=0%) in the BCG intervention group as compared with that in the placebo group. Conclusions. There is no robust evidence to support the use of the BCG vaccine for the treatment of T1DM although the HbA1c levels tended to improve. Additional RCTs to assess the long-term effects of the BCG vaccine on glycemic control are warranted.

In this study, a 3.5-GHz solidly mounted resonator (SMR) was developed by doping scandium in aluminum nitride to form AlScN as the piezoelectric thin film. Molybdenum (Mo) of 449 nm thickness and silicon dioxide (SiO2) of 371 nm thickness were used as the high and low acoustic impedance films, respectively, which were alternately stacked on a silicon substrate to form a Bragg reflector. Then, an alloy target with atomic ratio of 15% Sc was adopted to deposit the piezoelectric AlScN thin film on the Bragg reflector, using a radio frequency magnetron sputtering system. The characteristics of the c-axis orientation of the AlScN thin films were optimized by adjusting sputtering parameters as sputtering power of 250 W, sputtering pressure of 20 mTorr, nitrogen gas ratio of 20%, and substrate temperature of 300 °C. Finally, a metal top electrode was coated to form a resonator. The X-ray diffraction (XRD) analysis showed that the diffraction peak angles of the AlScN film shifted towards lower angles in each crystal phase, compared to those of AlN film. The energy dispersive X-ray spectrometer (EDX) analysis showed that the percentage of scandium atom in the film is about 4.5%, regardless of the sputtering conditions. The fabricated resonator exhibited a resonance frequency of 3.46 GHz, which was a small deviation from the preset resonance frequency of 3.5 GHz. The insertion loss of −10.92 dB and the electromechanical coupling coefficient of 2.24% were obtained. As compared to the AlN-based device, the AlScN-based resonator exhibited an improved electromechanical coupling coefficient by about two times.

We designed and fabricated bi-polar type photoconductive antenna (PCA) for efficient generation of broadband terahertz (THz) radiation. The falling time of overlayingly generated photocurrent from bi-polar PCA can achieve 200 fs via superimposing two primarily opposite polarity photocurrent pulses having falling time of 100 ps with time delay of 200 fs. The simulation results disclosed a possibility to shift the central frequency from 0.1 to 1.3 THz and enhance the THz power by twice in the range 1.5-3.3 THz by using low cost substrate with long carrier life time such as semi-insulating gallium arsenide (SI-GaAs).

Internalization of macromolecules and membrane into cells through endocytosis is critical for cellular growth, signaling and plasma membrane (PM) tension homeostasis. Although endocytosis is responsive to both biochemical and physical stimuli, how physical cues modulate endocytic pathways is less understood. Contrary to the accumulating discoveries on the effects of increased PM tension on endocytosis, less is known about how a decrease of PM tension impacts on membrane trafficking. Here, we reveal that an acute decrease of PM tension results in phosphatidic acid (PA) production, F-actin and phosphatidylinositol (4,5)-bisphosphate [PI(4,5)P2]-enriched dorsal membrane ruffling and subsequent macropinocytosis in myoblasts. The PA production induced by decreased PM tension depends on phospholipase D2 (PLD2) activation via PLD2 nanodomain disintegration. Furthermore, the ‘decreased PM tension–PLD2–macropinocytosis’ pathway is prominent in myotubes, reflecting a potential mechanism of PM tension homeostasis upon intensive muscle stretching and relaxation. Together, we identify a new mechanotransduction pathway that converts an acute decrease in PM tension into PA production and then initiates macropinocytosis via actin and PI(4,5)P2-mediated processes.

Internalization of macromolecules and membrane into cells through endocytosis is critical for cellular growth, signaling, and membrane tension homeostasis. Although endocytosis is responsive to both biochemical and physical stimuli, how physical cues modulate endocytic pathways is less understood. In contrary to the accumulating discoveries on effects of increased membrane tension on endocytosis, little is known about how a drop of tension impacts membrane trafficking. Here we reveal that acute reduction of plasma membrane tension results in phosphatidic acid, F-actin and dynamin 2-enriched dorsal membrane ruffling and subsequent macropinocytosis in myoblast. The membrane flaccidity-induced local phosphatidic acid production depends on phospholipase D2 (PLD2) that is activated via lipid raft disruption. Furthermore, the “membrane flaccidity-PLD2-macropinocytosis” pathway is dominant in myotube, reflecting a potential mechanism of membrane tension homeostasis upon intensive muscle stretching and relaxation. Together, we identify a new mechanotransduction pathway which converts acute tension drop into PA production and subsequently initiates macropinocytosis via actin and dynamin activities. Summary We reveal a mechanical induction of macropinocytosis that is elicited by acute decrease of plasma membrane tension, followed by lipid raft destabilization, PLD2 activation and PA production.

Introduction: Cerebral vasoconstriction is often encountered in the post-CPR phase, which inevitably worsens neurological prognosis. Nitric oxide (NO) confers vasodilatation and anti-apoptotic protective effect, but may cause systemic hypotension. We designed an Au-polymersomes/S-nitrosoglutathione (Au-PLGA/GSNO) nanoparticle that can be selectively triggered by shockwave (SW) to release NO, and investigated its role in mitigating post-CPR cerebral vasoconstriction and apoptotic neuronal injury. Methods: Using an established rat model of asphyxia cardiac arrest and CPR, Au-PLGA/GSNO (7500 PPM, 3.33 mg/kg Au and 42 ug/kg GSNO) was infused into carotid artery together with the same volume of SonoVue 10 min after CPR, with simultaneous stimulation by SW (PiezoWave, 134 mJ/mm 2 ) distal to the infusion site. The blood pressure (BP) was continuously monitored and brain tissue perfusion recorded by OxyFLO probe. Cerebral vasculature was video-taped by CytoCam. The blood was sampled 2 h post-CPR for measurement of nitrate/nitrite. The brain was harvested for measurement of casepase-3, endothelial NO synthase (eNOS) and protein kinase B (Akt). In a subgroup the brain was harvested at 24 h for TUNEL stain. Results: Marked cerebral vasoconstriction was noted after CPR with brain perfusion reduced to about half that of baseline. With infusion of Au-PLGA/GSNO + SonoVue and SW stimulation, the cerebral vasoconstriction was ameliorated and brain perfusion improved to baseline level ( P < 0.05 vs. CPR control), while BP showed no significant difference. The plasma nitrate/nitrite 2 h post-CPR was significantly increased ( P < 0.05). The cleaved caspase-3 of the brain was reduced ( P < 0.001) and TUNEL stain of the CA1 and CA3 regions of hippocampus significantly abrogated. Interestingly, the phosphorylated (P)-eNOS and P-Akt were also increased (both P < 0.001), suggesting reciprocating activation of the upstream Akt-eNOS signaling. Conclusion: Nano Au-PLGA/GSNO with SW-induced release of NO selectively mitigates post-CPR cerebral vasoconstriction and apoptotic neuronal death without systemic hypotension. Being effective and safe, such therapeutic strategy can be applied not only in post-CPR care but in other diseases such as subarachnoid hemorrhage.

A simple but effective electrochemical route to functionalize graphene is demonstrated. Cyclic voltammetric sweeps are performed in 0.5 M H2SO4 aqueous solution on electrodes containing carbon cloth, graphene, and Nafion ionomer. With supply of ambient oxygen, the formation of hydroxyl radicals from the oxygen reduction reaction during CV cycles initiates the decomposition of Nafion ionomer that engenders oxygenated functional groups on the graphene surface. Raman analysis suggests a minor change for the graphene structure. Exploring various amounts of Nafion ionomer, we determine the optimized conditions for graphene functionalization. Contact angle is used to evaluate the effect of Nafion ionomer decomposition. X-ray photoelectron spectroscopy is employed to study relevant functional groups. Afterwards, nanoparticles of Pd9Ru are synthesized and impregnated on those functionalized graphene (FGN) via a wet chemical reflux process. X-ray diffraction patterns of the as-synthesized samples suggest successful formation of alloy without presence of individual Pd and Ru nanoparticles. Images from transmission electron microscope confirm the average size of 3-4 nm. Subsequently, the Pd9Ru/FGN undergoes Cu under potential deposition, followed by a galvanic displacement reaction to deposit a Pt monolayer on the Pd9Ru surface (Pd9Ru@Pt). Intensive experimental work is ongoing to investigate the electrochemical active surface area (ECSA) and electrocatalytic activities of Pd9Ru@Pt/FGN.

In this study, alkaline-activated persulfate is used to treat groundwater that is contaminated with 1,2-dichloroethane (1,2-DCA)- and methyl tert-butyl ether (MTBE). The results show that alkaline-activated persulfate accelerates the degradation of 1,2-DCA. Vinyl chloride is produced because there is dehydrochlorination of 1,2-DCA at high pH. Although the rate of degradation of MTBE in alkaline-activated persulfate systems is decreased, there is a significant reduction in the accumulation of MTBE-degrading byproducts, tert-butyl alcohol and tert-butyl formate. Alkaline-activated persulfate degrades 1,2-DCA via the mechanisms of oxidation and dehydrochlorination, but oxidation alone contributes to the removal of MTBE. The use of low-cost basic oxygen furnace (BOF) slag increases the pH of the solution (>12) and allows the alkaline-activated persulfate reaction to proceed. No detectable heavy metals are released from the BOF slag in the persulfate system that is activated by BOF slag. The degradation of 1,2-DCA and MTBE follows the pseudo-first-order kinetics for all persulfate systems. Alkaline-activated persulfate causes a decrease in ORP because there is a high pH, which adversely affects the removal of contaminants if the contaminants do not undergo base-mediated degradation. Therefore, the performance in terms of contaminant removal must be evaluated before alkaline-activated persulfate is used for different compounds. This novel, slag-activated persulfate system is an environmentally friendly and cost-effective alternative to the remediation of groundwater.

Dispersants including Tween 20, Tween 40, Tween 60, and polyacrylic acid (PAA) were used to modify nanoscale zero-valent iron (nZVI). All dispersants dispersed nZVI effectively. PAA-modified nZVI was more stable than nZVI that was modified with Tween surfactant. Iron nanoparticles that were prepared using 0.5–5.0% (vol%) of PAA remained in suspension for more than 2 h. nZVI that was modified using Tween surfactant remained in suspension for 30–60 min, and there was complete sedimentation of bare iron in 10 min. When 2.0–5.0% (vol%) of Tween surfactant was used, the stability of the nZVI that was modified using Tween 20 was much better than that for nZVI that was modified using Tween 40 or Tween 60. The results for the transportation test show that nZVI that was prepared using 2% (vol%) of Tween 20 exhibited the best mobility in porous media. Approximately 83–90% of TCE was degraded by bare, PAA-modified, and Tween 20-modified nZVI, and about 63–67% of TCE was removed by nZVI that was modified using Tween 40 and Tween 60 during 20 days of reaction. The production of cis-dichloroethene (DCE) and 1,1-DCE demonstrates that TCE is removed via reductive dechlorination. The results of this study show that PAA- and Tween 20-modified nZVI are more practical for in situ remediation because they exhibit good mobility and degrade TCE effectively.

BACKGROUND In this study, batch experiments were conducted using diesel-contaminated soil collected from a former gas station to evaluate the efficiency of diesel removal by in situ chemical oxidation (ISCO) and the effects of different oxidants on the indigenous microbial community. RESULTS Diesel removal efficiencies by persulfate, permanganate, and hydrogen peroxide under different concentrations (1, 3, 5, and 10%) ranged from 48 to 93% during a 120-day reaction. The performance of diesel removal in the oxidant-alone systems was persulfate > permanganate > hydrogen peroxide. Oxidant persistence was positively correlated with diesel removal performance. Higher diesel removal efficiencies were observed in the chemical oxidation systems with the presence of microbes. The adverse effects of the oxidants on intrinsic microbes followed the sequence persulfate > permanganate ≈ hydrogen peroxide. The addition of hydrogen peroxide and permanganate caused increased microbial diversity while more serious destruction to the microbial community was observed in the persulfate solution due to low pH (

Nonylphenol (NP) is a non-ionic surfactant that is used widely as an industrial detergent. We have found that NP impairs male reproductive functions in vitro. However, the in vivo effects of NP on testosterone release at environmentally relevant doses remain unclear. Male rats were exposed to a low-dose of NP by oral gavage at 10 and 100 μg/kg body weight daily for 3-7 days. After 7 days of NP exposure, plasma testosterone level was significantly higher in higher NP exposure group than in the vehicle group. Higher basal testosterone release was found in the Leydig cells obtained from the rats treated with NP for 7 days. Additionally, evoked testosterone release was also higher after treating Leydig cells with human chorionicgonadotropin, 8-bromo-adenosine cyclic monophosphate, or forskolin. The expression of steroidogenic acute regulatory protein (StAR) was also increased by 40% in oral NP group. In contrast, the stimulatory effects were absent in Leydig cells treated with various steroid precursors. The stimulatory effects of NP were abolished after administration with intracellular calcium, EGFR and ERK blockers, which were well known to stimulate StAR activation. These results suggest that NP at an environmentally relevant dose could stimulate plasma testosterone level.

In this study, we investigated self-organized TiO 2 nanotubes that were grown using anodization of commercially pure titanium at 5 V or 10 V in NH 4 F/NaCl electrolyte. The nanotube arrays were annealed at 450 °C for 3 h to convert the amorphous nanotubes to anatase and then they were immersed in simulated body fluid at 37 °C for 0.5, 1, and 14 days. The purpose of this experiment was to evaluate the apatite-formation abilities of anodized Ti nanotubes with different tube diameters and lengths. The nanotubes that formed on the surfaces of Ti were examined using a field emission scanning electron microscope, X-ray diffraction, and X-ray photoelectron spectroscope. When the anodizing potential was increased from 5 V to 10 V, the pore diameter of the nanotube increased from approximately 24–30 nm to 35–53 nm, and the tube length increased from approximately 590 nm to 730 nm. In vitro testing of the heat-treated nanotube arrays indicated that Ca-P formation occurred after only 1 day of immersion in simulated body fluid. This result was particularly apparent in the samples that were anodized at 10 V. It was also found that the thickness of the Ca-P layer increases as the applied potential for anodized c.p. Ti increases. The average thickness of the Ca-P layer on Ti that was anodized at 5 V and 10 V was approximately 170 nm and 190 nm, respectively, after immersion in simulated body fluid for 14 days.

This study uses a trichloroethene (TCE)-contaminated site to determine the efficacy of persulfate oxidation for the treatment of TCE-contaminated groundwater. The main objectives of this study are: (1) to evaluate the efficacy of TCE treatment using persulfate with different injection strategies; (2) to determine the persistence of persulfate in the aquifer; (3) to determine the radius of influence (ROI) and transport distance of persulfate and (4) to determine the impact of persulfate on indigenous microorganisms during remediation. TCE concentrations are 0.26 mg L−1 in P143 and 0.361 mg L−1 in P146 and the microbial numbers are 6.1 × 103 CFU mL−1 in P143 and 4.4 × 104 CFU mL−1 in P146, before persulfate is injected. The results of the pilot study show that persulfate eliminates TCE. 100% of TCE is removed in P146 and 95% in P143. Single injection of a total amount of 275 kg of 5% persulfate produces better TCE removal than two half persulfate injections in sequence. The transport distance of persulfate ranges from 3.6 to 4.5 m. Persulfate also persists for 14 days in the aquifer. After persulfate is injected, the total bacterial counts decrease slightly to 2.4 × 103 CFU mL−1 in P143 and 1.8 × 103 CFU mL−1 in P146. When persulfate is consumed, the total bacterial counts increase but there is no recovery of the microbial community. The results show that sequential injections of a large amount of persulfate are suggested to maintain good long-term performance for TCE treatment.

Bidirectional dc-dc converter is an important part of battery energy storage to efficiently control the power flow in or out of the battery. Due to the limited stored energy, it is very important to maximize the amount of deliverable energy to the load by minimizing the losses in the power conversion. In this paper, the proposed high efficiency bidirectional DC-DC converter is based on series resonant converter (SRC) topology. The circuit is realized by using full bridge on primary and secondary side. Silicon carbide (SiC) MOSFET is utilized on the primary side to significantly reduce the losses on the primary side switches. A 1.5 kW 750V/ 15V prototype converter was implemented and tested to verify the design. From the experimental results, a 96.22% of peak efficiency for both buck and boost modes was achieved.

A microfluidic immunoassay system was developed for the study of the enhancement of protein binding reaction. The system mainly consisted of a thermopneumatic actuator and a reaction chamber. Reagent was pre-installed in the on-chip reservoir and manipulated by the actuator. Such design could eliminate the external tubing connections in order to reduce the waste of reagent and improve the portability. The on-chip actuator could manipulate the reagent bi-directionally to induce vortexes in the chamber. Enhancement of protein binding reaction was demonstrated by the protein model pair, i.e., mouse IgG and anti-mouse IgG. By such bi-directional fluid motion, more binding opportunities between suspended protein and its surface-immobilized counterpart were generated to improve the performance of immunoassay. It showed that an 83.74 % enhancement of the binding reaction was achieved, compared with the static situation. As a whole, the proposed microfluidic system is highly integrated and can enhance the protein binding efficiency using such novel design. The developed system can be easily extended to multi-reagents immunoassay protocols and provides a useful platform for point-of-care applications.

A series of anthracene and 2-tert-butyl–substituted anthracene derivatives featuring 9-ethyl-9H-carbazol-3-yl or 4-(9-ethyl-9H-carbazol-3-yl)phenyl groups were synthesized for use as light-emitting layer in sky-blue organic light emitting devices (OLEDs). Efficient conjugation between the carbazole and anthracene unit resulted in strong blue emissions and high quantum efficiencies of anthracene derivatives in solution. Electroluminescence (EL) properties of non-doped OLEDs incorporated with these anthracene derivatives, along with an electron-transporting layer (ETL), tri-(8-hydroxyquinoline)aluminum (Alq3) or 1,3,5-tris(N-phenyl benzimidizol-2-yl)benzene (TPBI) were investigated. The OLEDs incorporated with TPBI provided superior EL performance than did those incorporated with Alq3. A hole-blocking layer 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) was inserted at the interface of light emitting layer and ETL to enhance the EL performance for the OLED with Alq3 as ETL. High brightness (37423 cd/m2), and great current efficiency (5.89 cd/A) were observed for the 4-(9-ethyl-9H-carbazol-3-yl)phenyl-substituted anthracene derivatives based OLEDs.

In this study, a gasoline-contaminated site was selected to evaluate the biodegrading potential of methyl tert-butyl ether (MTBE) and benzene (B), toluene (T), ethylbenzene (E) and xylenes (X), collectively known as BTEX under aerobic, nitrate reducing, and methanogenic conditions at the site. Results show that in situ microorganisms had capabilities of degrading MTBE and BTEX using MTBE and BTEX as major carbon sources under aerobic condition. Under conditions of nitrate reduction and methanogenesis, BETX could be decomposed by in situ microorganism; but MTBE was not decomposed. The decomposition of BTEX under anaerobic condition was much slower than aerobic condition. Benzene had the slowest degrading rate. In addition, BTEX was decomposed faster and more completely under methanogenic condition than nitrate reducing condition. The on-site activated sludge system is effective in decomposing BTEX but not effective in decomposing MTBE. Results of this study reveal that the enhanced aerobic bioreme...

Size-tunable hollow carbon spheres containing encapsulated Ag microparticles (HCSA) were fabricated using a one-pot method for the coupled synthesis and encapsulation. These spheres were formed by the catalyzed dehydration of glucose under hydrothermal conditions, using the anionic surfactant sodium dodecyl sulfate (SDS) as a sacrificial template to tune the cavity size of the hollow carbon spheres. In this one-pot synthesis, glucose was used as the carbonaceous source and served as the reducing agent that reacted with Ag ions. The HCSA exhibited tunable cavity sizes (1.2–2.4 μm), dimensions (0.2–2.7 μm), and morphologies (hollow spherical, bowl-like, ruptured, or solid spherical). The obtained products were characterized using X-ray diffraction (XRD) analysis, field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform-infrared spectroscopy (FTIR), Raman spectroscopy, and nitrogen adsorption/desorption analysis. On the basis of the results obtained in this study, we suggest that the SDS concentration is the crucial factor in the fabrication of size-tunable HCSA. In addition, we propose a possible mechanism for the formation of the HCSA.

This research investigated the fouling effect of humic acid and humic acid/calcium ions on the rejection of three target compounds, i.e., acetaminophen, sulfamethoxazole, and triclosan, by two nanofiltration (NF) membranes. A modified Hermia fouling model was used to describe the fouling process. The effects of solute and membrane characteristics on the rejection and flux decline at various pH levels and with various foulants were also investigated. Results show that fouling mechanisms include complete blocking and gel layer formation. The presence of humic acid and humic acid/calcium ions may positively influence the rejection of hydrophilic compounds and neutral compounds rejected only by size exclusion. The experimental rejections of solute by the NF270 membrane correlate well with the theoretical rejection model in which only size exclusion was considered. For NF membranes with pore sizes larger than the solutes (e.g., the NTR7450 membrane), the rejection could be determined from the model combining both size exclusion and electrostatic exclusion.

In this study, we synthesized three anthracene derivatives featuring carbazole moieties as side groups – 2-tert-butyl-9,10-bis[4-(9-carbazolyl)phenyl]anthracene (Cz9PhAnt), 2-tert-butyl-9,10-bis{4-[3,6-di-tert-butyl-(9-carbazolyl)]phenyl}anthracene (tCz9PhAnt), and 2-tert-butyl-9,10-bis{4′-[3,6-di-tert-butyl-(9-carbazolyl)]biphenyl-4-yl}anthracene (tCz9Ph2Ant) – for use in blue organic light emitting devices (OLEDs). The anthracene derivatives presenting rigid and bulky tert-butyl-substituted carbazole units possessed high glass-transition temperatures (220 °C). Moreover, the three anthracene derivatives exhibited strong blue emissions in solution, with high quantum efficiencies (91%). We studied the electroluminescence (EL) properties of non-doped OLEDs incorporating these anthracene derivatives, with and without a hole-transporting layer (HTL). OLEDs incorporating an HTL provided superior EL performance than did those lacking the HTL. The highest brightness (6821 cd/m2) was that for the tCz9PhAnt-based device; the greatest current efficiency (2.1 cd/A) was that for the tCz9Ph2Ant-based device. The devices based on these carbazole-substituted anthracene derivatives also exhibited high color purity.

It has been speculated that maternal phthalate exposure may affect reproductive development in human newborns. However, the mechanism awaits further investigation. The aim is to evaluate the association between maternal phthalate exposure and cord sex steroid hormones in pregnant women and their newborns from the general population. A total of 155 maternal and infant pair were recruited and analyzed. Levels of urinary phthalate metabolites and sex steroid hormones were determined using liquid chromatography/electrospray tandem mass spectrometry (LC-ESI-MS/MS) and radioimmunoassay (RIA), respectively. No significant correlation was found between each steroid hormones and phthalate metabolites for male newborns, except MMP was marginally significantly correlated with E(2). After adjusting for maternal age, estradiol (E(2)) levels in cord serum from male newborns were not correlated with maternal urinary phthalate metabolites. In female newborns, the maternal urinary levels of mono-(2-ethylhexyl) phthalate (MEHP) and mono-(2-ethyl-5-hydroxyhexyl) phthalate (5OH-MEHP) were negatively correlated with the free testosterone (fT) and fT/E(2) levels in cord serum with Pearson correlation coefficients ranging between -0.24 and -0.29 (p0.05). Additionally, after gestational age was adjusted, the maternal urinary level of DEHP was negatively correlated with the free testosterone (fT) and fT/E(2) levels in cord serum. We suggest that maternal exposure to phthalates may affect sex steroid hormones status in fetal and newborn stage.

A hollow fiber bioreactor (HFB) culture system coupled with a tangential flow filtration (TFF) device was used for HepG2 cell secretome analysis. In order to reduce the loss of low-molecular-weight proteins, two new features, the hollow fiber with 0.1 μm pore size and a TFF device with a membrane of 1kDa molecular weight cutoff, were added to the system described previously. The HFB culture system and the conventional dish culture method for secretome collection were compared side by side. It was observed that only a small fraction of cells (

A congener profile of polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs) could provide valuable information for identifying possible sources of exposure to these compounds. The purpose of this study is to identify factors associated with PCDD/F congener profiles in the general population of Taiwan. Serum samples from 251 subjects of the general population in Taiwan were collected, and the levels of 17 2,3,7,8-chlorinated substituted PCDD/Fs were measured. The relationships between PCDD/F congener profiles and demographic parameters were evaluated using a multivariate analysis of variance method (MANOVA). Of the five demographic factors investigated, age was found to have the greatest impact on PCDD/F congener profiles. The PCDD/F congener pattern for the group I subjects (aged 18-29) was significantly different from those for the other three older age groups (p0.001), and 12 congeners contributed to the effects (difference index: 71%). In addition, the group I subjects did not exhibit trends parallel to those of the other groups in the relationship between age and PCDD/F levels. Age was associated with PCDD/F levels and congener profiles in the general population of Taiwan and the young subjects (aged 18-29) was quite different from the other older subjects that could be influenced by the individual differences in pharmacokinetics and/or background exposure from dietary sources. We conclude that investigators must consider subjects' age and other underlying factors that could influence PCDD/F congener profiles in humans when identifying exposure sources.

Polyaniline (PANI)/maghemite (γ-Fe 2 O 3 ) nanocomposites were prepared by using the reverse micelle polymerization, where aniline, ferrous and ferric salts and sodium dodecyl sulfate (SDS) act as monomer, precursor of γ-Fe 2 O 3 and surfactant, respectively. The effect of the molar ratio of [SDS]/[H 2 O] on the electromagnetic properties of PANI/γ-Fe 2 O 3 nanocomposites was investigated by Fourier transform spectroscopy (FTIR), UV–visible spectroscopy (UV–vis), X-ray photoelectron spectroscopy (XPS), wide angle X-ray diffraction diffractometer (WAXD), impedance analysis analyzer, micro-ohmetry and superconductor quantum interference device (SQUID). The nanostructure of the PANI/γ-Fe 2 O 3 nanocomposites was characterized by micrographs of transmission electron microscopy (TEM). Results showed that both the γ-Fe 2 O 3 content and particle size in the nanocomposites decreased with molar ratio of [SDS]/[H 2 O]. The γ-Fe 2 O 3 phase is non-uniformly distributed in the PANI matrix, and exhibits a broader size distribution at higher [SDS]/[H 2 O] molar ratio due to the reduced strength of PANI–γ-Fe 2 O 3 interactions. In the presence of γ-Fe 2 O 3 , the growth rate of quinoid ring is markedly retarded. The retard effect is significantly reduced by increasing the [SDS]/[H 2 O] molar ratio, leading to the improvement of crystallinity, conductivity and dielectric properties (i.e., permittivity and loss factor) of nanocomposites. Simultaneously, the ionic polarization relaxation time is shortened from 2.61 × 10 −9 to 1.04 × 10 −9 s. For SQUID analysis at room temperature, the typical superparamagnetic behavior is found with the saturation magnetization decreased with the [SDS]/[H 2 O] molar ratio, resulting from the reduced γ-Fe 2 O 3 content, smaller γ-Fe 2 O 3 particle size, and the wider particle size distribution.

The cure kinetics of epoxy–novolac compounds were studied by means of differential scanning calorimetry with a dynamic approach. On the basis of a modified version of our previously reported kinetic model, a procedure aiming at the phenomenological description of the cure kinetics was developed. The reactions were found to be autocatalytic in nature for both commercial epoxy–novolac molding compounds and silica-free imidazole-cured epoxy–novolac systems. The weak extent of autocatalysis in the epoxy–novolac molding compounds was likely due to their high content of silica fillers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Poly(vinylidene chloride-co-vinylchloride)/organically modified hectorite (VDC-VC/SPN) nanocomposites were prepared by melt blending VDC-VC copolymer with SPN in the presence of dioctyl phthalate, which acted as a plasticizer. As a result, the exfoliated structure was found in the VDC-VC/SPN nanocomposites. In nitrogen atmosphere, VDC-VC/SPN nanocomposites exhibited a single-step thermal degradation. The thermal stability of VDC-VC/SPN nanocomposites is significantly influenced by the SPN, which was modified with long alkyl ternary ammonium salt. In air atmosphere, VDC-VC/SPN nanocomposites revealed a two-step thermo-oxidative degradation behavior. At the first degradation stage, the weight loss pattern is similar to that of VDC-VC composites in nitrogen, in which the thermo-oxidative stability of VDC-VC/SPN nanocomposites is affected by the ternary ammonium salt and oxygen rather than its morphology. At the second degradation stage, both the enhanced thermo-oxidative stability and the flame-retardation ability of VDC-VC composites are strongly and closely related to the morphology of nanocomposites. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci ,2009

Polyaniline coated silica/maghemite nanoparticles (PANI/SiO2/γ-Fe2O3 composites) were synthesized by the combination of a sol–gel process and an in-situ polymerization method, in which ferrous and ferric salts as well as tetraethyl orthosilica (TEOS) acted as the precursor for γ-Fe2O3 and silica, respectively. As a result, the SiO2/γ-Fe2O3 particle showed a core-shell structure, with γ-Fe2O3 as the magnetic core and silica as the shell of the particle. The shell thickness can be controlled by changing the TEOS concentration. The PANI/SiO2/γ-Fe2O3 composites revealed a multilayer core-shell structure, where PANI is the outer shell of the composite. The doping level and the conductivity of PANI/SiO2/γ-Fe2O3 composites decreased with increasing the TEOS content due to the presence of the less coated PANI on the SiO2/γ-Fe2O3 core at higher TEOS content. For a SQUID analysis at room temperature, all γ-Fe2O3 containing composites showed a typical superparamagnetic behavior. The saturation magnetization of SiO2/γ-Fe2O3 nanoparticles decreased with increasing the TEOS content due to the increase in silica shell thickness, while the saturation magnetization of PANI/SiO2/γ-Fe2O3 composites also decreased with increasing the TEOS content, which is attributed to the lower conductivity of PANI in the composites at higher TEOS content.

The levels of estrogens and/or their metabolites play important roles in carcinogenesis, reproductive function, and sexual development during perinatal and adolescence periods. The main purpose of this report was to investigate the applicability of high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) with electrospray ionization (ESI) and/or atmospheric pressure chemical ionization (APCI) for simultaneous detection of estrone (E1) and its six metabolites. Both positive and negative ionization modes in ESI and APCI were used to evaluate the signal responses of seven target analytes. Among the seven target analytes, five analytes, E1, 16alpha-hydroxyestrone, 2-methoxyestrone, 4-methoxyestrone, and 2-hydroxyestrone-3-methyl, produced signals with the best signal-to-noise (S/N) ratios in positive APCI-MS/MS mode, while the other two analytes, 2-hydroxyestrone and 4-hydroxyestrone, yielded the best S/N ratios in negative ESI-MS/MS mode. Based on the results of the evaluation, HPLC-APCI-MS/MS with switching between positive and negative modes was recommended for simultaneous detection of E1 and its six metabolites. The proposed analytical scheme was successfully applied in the analysis of cell culture medium of Human liver carcinoma cells treated with varying amounts of 2,3,7,8-tetrachlorodibenzo-p-dioxin.

The formation of incense smoke generated from four different types of incense sticks, three manufactured in Taiwan and one in Japan, was investigated in a small controlled chamber. The scanning mobility particle sizer and the quartz crystal microbalance were used for particle size analyses. The count median diameter (CMD) was found to rise swiftly along the path of the incense smoke. Consequently, a representative sampling location was selected for all measurements performed thereafter. All four types of incense smoke were shown to exhibit characteristic size distributions, CMDs, and mass median aerodynamic diameters (MMADs). Electron microscopy depicted liquid and solid nature of Taiwan and Japan incense smoke, respectively. The different physical states of the particles were suspected to be a result of different smoke-generating ingredients used by different cultures. Finally, the formation mechanisms of both liquid and solid incense smoke were discussed.

The object of this research was to investigate the effects of various precursors and different fabricating procedures of Pd/Al 2 O 3 –CeO 2 catalysts by the sol–gel method. The physicochemical properties and structures of catalyst were characterized with BET surface area, X-ray powder diffraction (XRPD), and scanning electron microscopy (SEM). The performance of the Pd/Al 2 O 3 –CeO 2 catalyst was also evaluated by CO oxidation tests with a continuous quartz reactor. The results indicated that the catalyst prepared with inorganometallic precursors showed a high dispersion of Pd, large surface area and pore volume, and a high activity in CO oxidation. The higher redox interaction between Pd and Ce of the support starting with inorganometallic precursors, as determined from X-ray powder diffraction, is suggested as being responsible for such a catalytic behavior.

A commercial sample of LiCoO2 was coated with ZrO2 by sol‐gel and mechano‐thermal processes. The effects of the coating method and the precursor used in the sol‐gel coating process were studied. Electron microscopic images of the coated particles revealed the presence of a compact coating over the cathode particles. XRD and ESCA results suggested the formation of substitutional compounds of the composition Li x Zr y Co1‐yO2 + 0.5y on the surface of the cathode. Coating levels of 0.3 and 1.0 wt.% were found to be optimal in terms of cyclability for the materials coated by the sol‐gel and mechano‐thermal methods, respectively. At these coating levels, the R‐factor values, determined from XRD data, were the lowest. The maximum improvements in cyclability registered at a 0.2 C rate were about eight‐fold with the sol‐gel and mechano‐thermal coating methods. Cyclic voltammetric studies showed that the coating led to a suppression of the cycle‐limiting phase transitions accompanying the charge‐discharge...

The cycling properties of LiCoO2 coated with TiO2 by a sol–gel process from an alkoxide precursor and a mechano-thermal process from pre-formed nanoparticles are compared. Electron microscopic images of 1.0 wt.% TiO2-coated particles revealed that the oxide formed a compact coating over the cathode particles. XRD studies showed a general decrease in the value of the lattice parameter c upon coating, indicating that substitutional compounds might have formed on the surface during calcination. R-factor values from XRD studies and galvanostatic charge–discharge studies suggested that a coating level of 1.0 wt.% was optimal for materials with good cycling characteristics. While the sol–gel coating process enhanced cyclability 5-fold, the mechano-thermal process yielded materials that exhibited a 12-fold improvement. The enhanced cyclability is attributed to a suppression of the cycle-limiting hexagonal/monoclinic/hexagonal phase transitions accompanying the charge–discharge processes. Materials with better electrochemical characteristics could be obtained by the mechano-thermally coating process than sol–gel. Furthermore, the mechano-thermal coating process is a simple, inexpensive, environmentally benign and commercially viable one for the production of high-cycling LiCoO2 cathode materials.

The composite membranes were prepared by impregnation of porous poly(tetrafluoroethylene) membranes with a 5 wt% Nafion solution. Scanning electron microscope micrographs of composite membranes show the surface and cross section of poly(tetrafluoroethylene) membranes were covered and filled with Nafion resin. Comparison of physical properties and fuel cell performance of composite membranes with those of Nafion membranes (DuPont Co) is presented. The composite membrane has better thermal stability and gas barrier property but worse ionic conductivity than Nafion membrane. Though the composite membrane has a lower conductivity than Nafion membrane, however, owing to the thinner thickness of composite membrane (in thickness of 20±5 µm) than Nafion-115 (in thickness of 125 µm) and Nafion-117 (in thickness of 175 µm) membranes, the composite membrane has a shorter H+ ion transporting pathway and thus a higher conductance (conductance = conductivity/membrane thickness) than Nafion-115 and Nafion-117 membranes. Thus the composite membrane has a better fuel cell performance than Nafion-117 and Nafion-115 membranes. In this report, we show that our composite membrane has a fuel cell performance similar to Nafion-112 membrane (in thickness of 50 µm).

An isotope-dilution electrospray ionization tandem mass spectrometry (ESI-MS/MS) method with an on-line sample clean-up device, for the quantitative analysis of human urine for the benzene exposure biomarker S-phenylmercapturic acid (SPMA), was developed and validated. The sample clean-up system was constructed from an autosampler, a reversed-phase C18 trap cartridge, a two-position switching valve, and controlling computer software and hardware. The sample clean-up system was interfaced via 1/20 splitting to the ESI source of a triple-quadrupole mass spectrometer using negative ion mode and multiple reaction monitoring for SPMA and the isotope-labeled internal standard. A strategy was adopted to acquire pooled blank urine matrix and quality control samples spiked with standards. Validated procedures and data on method specificity, detection limits, standard curves, precision and recovery, sample storage stability, and inter-laboratory comparison are presented. The analytical system was fully automated. No tedious manual sample clean-up procedures are required. With the selectivity and the sensitivity provided by ESI-MS/MS detection, the analytical system can be used for high-throughput and accurate determination of SPMA levels in human urine samples, as a biomarker for environmental as well as occupational benzene exposure. Copyright © 2004 John Wiley & Sons, Ltd.

The antioxidant activity of 3-dehydroshikimic acid (DHS), an intermediate in the biosynthesis of aromatic amino acids, was evaluated in three assay systems: bulk oil (lard), liposomes, and a 10% corn oil-in-water emulsion. Upon initiation of peroxidation in the liposome or emulsion systems, DHS exhibited weak antioxidant activity. In contrast, DHS displayed strong antioxidant activity in lard, suppressing peroxidation with activity comparable to that of tert-butylhydroquinone, propyl gallate, and gallic acid and superior to that of alpha-tocopherol. Two major DHS oxidation products, gallic acid and protocatechuic acid, were identified by gas chromatography/mass spectral analysis of lard extracts; both compounds are effective antioxidants in the bulk oil system. In the liposome system, DHS remained intact throughout the assay period. A small amount of gallic acid was observed in extracts of the emulsion; however, protocatechuic acid was not detected. A mechanism to explain the different activities of DHS in the three lipid systems is proposed.

A specific and sensitive method using high-performance liquid chromatography-tandem mass spectrometry (LC-MS-MS) equipped with automatic on-line solid-phase extraction device for the quantitative measurement of anabolic hormone residues, 4-androstene-3,17-dione, testosterone and dihydrotestosterone in cell culture medium was developed. Steroid content in cell culture medium was determined directly without an additional sample preparation step. Separation of analytes from polar endogenous compounds was carried out on an automatic column-switching device coupled with a C4-alkyl-diol silica restricted-access solid-phase extraction column. The lipophilic fraction containing anabolic hormone residues were back-flushed on to a conventional C-18 reversed-phase column for the final chromatography. The analyte was ionized in an ElectroSpray interface under positive ion mode before entering a quadrupole mass analyzer. The lowest points of calibration curves were 0.05 ng ml−1 for 4-androstene-3,17-dione and testosterone, and 1 ng ml−1 dihydrotestosterone, respectively. A comparison with results from radioimmunoassay (RIA) is also presented.

The photooxidation of diphenylamine (DPA) and triphenylphosphine (P(C6H5)3) sensitized by 9,10-dicyanoanthracene (DCA) and 9-cyanoanthracene (CA) was investigated in this work. Theoretically and ev...

The reaction between three different Ca-based sorbents and SO2 were studied in a medium temperature range (473-773 K). The largest SO2 capture was found with Ca(OH)2 at 773 K, 126.31 mg SO2 x g Ca(OH)2(-1), and the influence of SO2 concentration on the sorbent utilization was observed. Investigations of the internal porous structure of Ca-based sorbents showed that the initial reaction rate was controlled by the surface area, and once the sulfated products were produced, pore structure dominated. To increase the surface area of Ca-based sorbents available to interact with and retain SO2, one kind of CaO/ activated carbon (AC) sorbent/catalyst was prepared to study the effect of AC on the dispersion of Ca-based materials. The results indicated that the Ca-based material dispersed on high-surface-area AC had more capacities for SO2 than unsupported Ca-based sorbents. The initial reaction rates of the reaction between SO2 and Ca-based sorbents and the prepared CaO/AC sorbents/catalysts were measured. Results showed that the reaction rate apparently increased with the presence of AC. It was concluded that CaO/AC was the active material in the desulfurization reaction. AC acting as the support can play a role to supply O2 to increase the affinity to SO2. Moreover, when AC is acting as a support, the surface oxygen functional group formed on the surface of AC can serve as a new site for SO2 adsorption.

In this study, the biodegradability of nanoscale zero-valent iron (nZVI) dispersants and their effects on the intrinsic biodegradation of trichloroethylene (TCE) were evaluated. Results of a microcosm study show that the biodegradability of three dispersants followed the sequence of: polyvinyl alcohol-co-vinyl acetate-co-itaconic acid (PV3A) > polyoxyethylene (20) sorbitan monolaurate (Tween 20) > polyacrylic acid (PAA) under aerobic conditions, and PV3A > Tween 20 > PAA under anaerobic conditions. Natural biodegradation of TCE was observed under both aerobic and anaerobic conditions. No significant effects were observed on the intrinsic biodegradation of TCE under aerobic conditions with the presence of the dispersants. The addition of PAA seemed to have a slightly adverse impact on anaerobic TCE biodegradation. Higher accumulation of the byproducts of anaerobic TCE biodegradation was detected with the addition of PV3A and Tween 20. The diversity of the microbial community was enhanced under aerobic conditions with the presence of more biodegradable PV3A and Tween 20. The results of this study indicate that it is necessary to select an appropriate dispersant for nZVI to prevent a residual of the dispersant in the subsurface. Additionally, the effects of the dispersant on TCE biodegradation and the accumulation of TCE biodegrading byproducts should also be considered.

Indole-3-carbinol (I3C), a component of Brassica vegetables, is under study as a preventive agent of cancers of the breast and other organs. Following ingestion, I3C is converted to a series of oligomeric products that presumably are responsible for the in vivo effects of I3C. We report the effects of the major trimeric product, 5,6,11,12,17,18-hexahydrocyclonona[1,2-b:4,5-b':7,8-b' ']triindole (CTr), on the estrogen receptor (ER) signaling pathways. Tumor-promoting effects of high doses of I3C may be due to activation of aryl hydrocarbon receptor (AhR)-mediated pathways; therefore, we also examined the effects of CTr on AhR activated processes. We observed that CTr is a strong agonist of ER function. CTr stimulated the proliferation of estrogen-responsive MCF-7 cells to a level similar to that produced by estradiol (E(2)) but did not affect the growth of the estrogen-independent cell line, MDA-MD-231. CTr displaced E(2) in competitive-binding studies and activated ER-binding to an estrogen responsive DNA element in gel mobility shift assays with EC(50)s of about 0.1 microM. CTr activated transcription of an E(2)-responsive endogenous gene and exogenous reporter genes in transfected MCF-7 cells, also with high potency. CTr failed to activate AhR-mediated pathways, consistent with the low-binding affinity of CTr for the AhR reported previously. Comparisons of the conformational characteristics of CTr with other ER ligands indicated a remarkable similarity with tamoxifen, a selective ER antagonist used as a breast cancer therapeutic agent and suggest an excellent fit of CTr into the ligand-binding site of the ER.