Facile preparation of environmental benign LED white light active humic acid nanolayer coated titanium dioxide photocatalyst for bisphenol A degradation.

Natural organic matter is a mixture of microbial decomposition products widely found in surface and groundwater. These organic materials have great potential as carbon-based precursors for chemical synthesis. This work demonstrated the development of a green photocatalyst via a facile adsorption process that combined colloidal titanium dioxide (TiO2) with humic acid. The resulting photocatalyst was visible light active and able to completely degrade 5 mg/L of BPA within 6 h under the irradiation of energy-efficient LED white light. The first-order kinetic rate constant of the reaction was determined to be 1.7 × 10-2 min-1. The enhanced photocatalytic activity was attributed to the decreased band gap energy and effective charge separation that limits the photogenerated electron-hole recombination. The outcome of this research opened an opportunity for the development of sustainable functional materials using natural organic matter.

Intelligent De Novo Design of Novel Antimicrobial Peptides against Antibiotic-Resistant Bacteria Strains.

Because of the growing number of clinical antibiotic resistance cases in recent years, novel antimicrobial peptides (AMPs) may be ideal for next-generation antibiotics. This study trained a Wasserstein generative adversarial network with gradient penalty (WGAN-GP) based on known AMPs to generate novel AMP candidates. The quality of the GAN-designed peptides was evaluated in silico, and eight of them, named GAN-pep 1-8, were selected by an AMP Artificial Intelligence (AI) classifier and synthesized for further experiments. Disc diffusion testing and minimum inhibitory concentration (MIC) determinations were used to identify the antibacterial effects of the synthesized GAN-designed peptides. Seven of the eight synthesized GAN-designed peptides displayed antibacterial activity. Additionally, GAN-pep 3 and GAN-pep 8 presented a broad spectrum of antibacterial effects and were effective against antibiotic-resistant bacteria strains, such as methicillin-resistant Staphylococcus aureus and carbapenem-resistant Pseudomonas aeruginosa. GAN-pep 3, the most promising GAN-designed peptide candidate, had low MICs against all the tested bacteria. In brief, our approach shows an efficient way to discover AMPs effective against general and antibiotic-resistant bacteria strains. In addition, such a strategy also allows other novel functional peptides to be quickly designed, identified, and synthesized for validation on the wet bench.

The thermal degradation and soil recovery of thermal treatment of field-weathered decabrominated diphenyl ether-contaminated soil.

A farm at Taoyuan in Taiwan was highly contaminated with decabrominated diphenyl ether (BDE-209), a widely used commercial brominated flame retardant and persistent in the environment, more than 10 years. Since crops are able to absorb and accumulate BDE-209 from soils in our previous research, posing a hazardous risk for humans, it is essential to develop a practical method of soil treatment. Thermal treatment was studied among different approaches. In our previous study (Ko et al., 2022), we found that heating to 450 °C for 30 min achieved a complete removal of BDE-209 in soil. However, the high temperature significantly decreased the original soil organic matter (SOM) from 2.47% to 0.27%, altering the soil texture, damaging microbial biomass, and thus affecting the revegetation after the thermal treatment. Sugarcane bagasse, a common agricultural residue, served as an amendment to restore soil fertility. Current results indicate that 2.5% bagasse can improve the SOM in soil by up to 2.73% and restore its bacterial composition, making the plant growth conditions similar to those of the untreated contaminated soil. In light of the high removal efficiency provided by the 450°C-thermal treatment and the high recovery efficiency of sugarcane bagasse, the strategy presented in this study serves to be a promising method for sustainable remediation.

Improving Patient Safety Culture During the COVID-19 Pandemic in Taiwan.

Background and Aim: Patient safety culture attitude is strongly linked to patient safety outcomes. Since the onset of the COVID-19 pandemic in early 2020, pandemic prevention has become the priority of hospital staff. However, few studies have explored the changes in patient safety culture among hospital staff that have occurred during the pandemic. The present study compared the safety attitudes, emotional exhaustion (EE), and work-life balance (WLB) of hospital staff in the early (2020) and late (2021) stages of the COVID-19 pandemic and explored the effects of EE and WLB on patient safety attitudes in Taiwan. Materials and Methods: In this cross-sectional study, the Joint Commission of Taiwan Patient Safety Culture Survey, including the six-dimension Safety Attitudes Questionnaire (SAQ) and EE and WLB scales, were used for data collection. Results: This study included a total of 706 hospital employees from a district hospital in Taipei City. The respondents' scores in each SAQ sub-dimension (except for stress recognition) increased non-significantly from 2020 to 2021, whereas their EE and WLB scores improved significantly (P < 0.05 and P < 0.01, respectively). The results of hierarchical regression analysis indicated that although a respondent's WLB score could predict their scores in each SAQ sub-dimension (except for stress recognition), EE was the most important factor affecting the respondents' attitudes toward patient safety culture during the later stage of the COVID-19 pandemic. Conclusion: In the post-pandemic, employees' attitudes toward safety climate, job satisfaction, and perception of Management changed from negative to positive. Additionally, both EE and WLB are key factors influencing patient safety culture. The present study can be used as a reference for hospital managers to formulate crisis response strategies.

A metagenomics study of hexabromocyclododecane degradation with a soil microbial community.

Hexabromocyclododecanes (HBCDs) are globally prevalent and persistent organic pollutants (POPs) listed by the Stockholm Convention in 2013. They have been detected in many environmental media from waterbodies to Plantae and even in the human body. Due to their highly bioaccumulative characterization, they pose an urgent public health issue. Here, we demonstrate that the indigenous microbial community in the agricultural soil in Taiwan could decompose HBCDs with no additional carbon source incentive. The degradation kinetics reached 0.173 day-1 after the first treatment and 0.104 day-1 after second exposure. With additional C-sources, the rate constants decreased to 0.054-0.097 day-1. The hydroxylic debromination metabolites and ring cleavage long-chain alkane metabolites were identified to support the potential metabolic pathways utilized by the soil microbial communities. The metagenome established by Nanopore sequencing showed significant compositional alteration in the soil microbial community after the HBCD treatment. After ranking, comparing relative abundances, and performing network analyses, several novel bacterial taxa were identified to contribute to HBCD biotransformation, including Herbaspirillum, Sphingomonas, Brevundimonas, Azospirillum, Caulobacter, and Microvirga, through halogenated / aromatic compound degradation, glutathione-S-transferase, and hydrolase activity. We present a compelling and applicable approach combining metagenomics research, degradation kinetics, and metabolomics strategies, which allowed us to decipher the natural attenuation and remediation mechanisms of HBCDs.

Clinical characteristics and long-term outcome of cerebral cavernous malformations-related epilepsy.

OBJECTIVE: Cerebral cavernous malformations (CCMs) present variably, and epileptic seizures are the most common symptom. The factors contributing to cavernoma-related epilepsy (CRE) and drug resistance remain inconclusive. The outcomes of CRE after different treatment modalities have not yet been fully addressed. This study aimed to characterize the clinical features of patients with CRE and the long-term seizure outcomes of medical and surgical treatment strategies. METHODS: This was a retrospective cohort of 135 patients with CCM who were diagnosed in 2007-2011 and followed up for 93.6 months on average. The patients were divided into drug-resistant epilepsy (DRE; n = 29), non-DRE (n = 45), and no epilepsy (NE; n = 61). RESULTS: Temporal CCM was the factor most strongly associated with the development of both CRE and DRE. The majority of patients with single temporal CCMs had CRE (86.8%, n = 33), and 50% had DRE, whereas only 14.7% (n = 5) with a nontemporal supratentorial CCM had DRE (p < .05). The most common lesion site in the DRE group was the mesiotemporal lobe (50%). Multiple CCMs were more frequently observed in the CRE (29.2%) than the NE (11.5%) group (p < .05). In patients with CRE, multiple lesions were associated with a higher rebleeding rate (odds ratio = 11.1), particularly in those with DRE (odds ratio = 15.4). The majority of patients who underwent resective surgery for DRE (76.5%, n = 13) achieved International League Against Epilepsy Class I and II seizure outcomes even after a long disease course. SIGNIFICANCE: Temporal CCM not only predisposes to CRE but also is a major risk factor for drug resistance. The mesiotemporal lobe is the most epileptogenic zone. Multiple CCMs are another risk factor for CRE and increase the rebleeding risk in these patients. Surgical resection could provide beneficial long-term seizure outcomes in patients with DRE.

Rapid debromination of tetrabromobisphenol A by Cu/Fe bimetallic nanoparticles in water, its mechanisms, and genotoxicity after treatments.

Tetrabromobisphenol A (TBBPA), a widely used brominated flame retardants, has been detected in various environmental matrices and is known to cause various adverse effects on human bodies. This study examined the feasibility and effectiveness of remediating TBBPA using Cu/Fe bimetallic nanoparticles (Cu/Fe BNPs) at various environmental and operational conditions. In general, TBBPA removal rate and debromination efficiency increased with higher Cu doping, higher Cu/Fe BNPs loading, higher temperature, and lower pH. At optimal conditions, TBBPA was completed removed at a rate constant > 0.2 min-1 where over 90% TBBPA was transformed to BPA within 30 min. The activation energy was found to be 35.6 kJ/mol, indicating that TBBPA was predominantly removed via surface-controlled reactions. Under pH 3-7 and ≥ 25 °C, debromination was the dominant removal mechanism compared to adsorption. The complete debromination pathway and the time-evolution of intermediates byproducts at different pHs were also presented. Cu/Fe BNPs can be reused for more than 6 times with performance constancy. Genotoxic tests showed that the treated solution did not find a significant hazardous potential. The byproducts can be further degraded by additional H2O2 through Fenton reaction. These results demonstrated the efficacy of Cu/Fe BNPs for treating TBBPA and its potential for degrading other halogenated organic compounds.

Effective photocatalytic degradation of sulfamethoxazole using tunable CaCu3Ti4O7 perovskite.

Sulfamethoxazole (SMX) is largely prescribed for bacterial infections but raises a major concern over generation of antibiotic-resistant bacteria in the environment. This study employed various perovskite-type photocatalysts, made by two-step synthesis procedures, to remove SMX. The as-synthesized CaCu3Ti4O7 (CCTO) perovskites were characterized by XRD, SEM-EDX, and DLS. Complete degradation (∼99%; kobs = 0.0279 min-1) of SMX was recorded under UV-light irradiation for 90 min in the presence of CCTO. SMX removal rate was investigated under various reaction conditions including pH, catalyst dose, electrolyte (NaCl and NaBr). The astonishing rate of SMX removal (kobs = 0.0614 min-1) was observed with the addition of 50 mM NaBr electrolytes in the reaction, which might imply that the appearance of halogen reactive species. CCTO-MS particles were aggregated in traces when the electrolytes concentration increases, resulting in reduced rate of SMX. The SMX concentration abatement and the formation of possible intermediates during photocatalytic reaction were analyzed. The upshot of this study reveals that the inexpensive and environmentally benign CCTO perovskite photocatalyst could be applied for the treatments of emerging contaminants in the future.

Thermal treatment of decabrominated diphenyl ether in its highly contaminated soil in Taiwan.

Polybrominated diphenyl ethers (PBDEs) were commonly used flame retardants in the world, while some of PBDEs have been listed as persistent organic pollutants (POPs). Decabrominated diphenyl ether (BDE-209) was the most commercially used PBDEs. A farm near the factory located in Northern Taiwan was highly contaminated with BDE-209. Since PBDEs in the contaminated soils can be uptake by crops shown in our previous studies and could be potentially consumed by humans, it is very important to establish a feasible treatment method for PBDE remediation in this contaminated farm. Thermal treatment of PBDEs in soil was studied. The initial concentration of BDE-209 in contaminated soil was 1.472 mg/kg. A series of thermal experiments under different operating conditions including various temperature (105, 150, 200, 250, 300, 350, 400 and 450 °C), holding time (10, 20 and 30 min), heating rate (5, 10, 20 and 40 °C/min), and soil amount (10, 100, 1000 and 2000 g) were investigated. The optimal heating conditions for thermal treatment of contaminated soil were heating at 450 °C for 30 min with a heating rate of 10 °C/min. Under this condition, the removal of BDE-209 in the different weights of contaminated soil was tested. The soils in the contaminated farm were tested to further evaluate the feasibility of remediating the on-site PBDE contaminated soil through thermal treatment, suggesting that the holding time was extended to 2 h for the field-scale contaminated soil. The results showed that BDE-209 had been removed to below the detection limit in on-site soil. This investigation is the first study using thermal treatment to remediate soils really contaminated with PBDEs.

Efficient hexabromocyclododecane-biodegrading microorganisms isolated in Taiwan.

The potential toxicity of hexabromocyclododecane (HBCD), its persistence in the environment, and its high bioaccumulation characteristics pose a need to remediate HBCD in the environment. Bacillus cereus and B. subtilis species complexes we isolated from Taiwan soil are capable of degrading HBCD. B. cereus can degrade HBCD with a half-life only 0.911 days. The highest efficiency of HBCD degradation by B. cereus was achieved at pH 7.0, 35 °C, and 0.10 ppm HBCD. The removal mechanism of HBCD by B. cereus is debromination and its pathway was proposed. The addition of surfactant Tween 60 improved HBCD removal but the addition of CaO2, slow-releasing oxygen, did not. These findings can facilitate the bioremediation of HBCD in the environment.

New insights of metal free 2D graphitic carbon nitride for photocatalytic degradation of bisphenol A.

Polymeric oxygen rich exfoliated graphitic carbon nitride (exfoliated GCN, EGCN) was synthesized by the acid treatment of bulk GCN. The photocatalyst was characterized using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and point of zero charge. EGCN shows high valance band hole transfer under short-time visible light (λ > 420 nm) exposure for photocatalytic mineralization of bisphenol A (BPA). Enhanced BPA removal was achieved by EGCN (99 %) due to formation of OH● radicals (H2O/hVB+ →OH●/H+). Major factors affecting BPA degradation including catalyst dose, wide pH range, and pollutant concentration were optimized. Repeated cycles of BPA degradation were performed with negligible rate decreased from 0.045 to 0.029 min-1. The degradation profile and plausible reaction mechanism of BPA was established and well justified by the byproducts identified by mass analysis HR-ESI-MS. Therefore, the as-synthesized metal free EGCN, active under visible light, offers a new platform for complete mineralization of byproducts of halogenated organic contaminants.

Aerobic degradation and the effect of hexabromocyclododecane by soil microbial communities in Taiwan.

Hexabromocyclododecane (HBCD) is one of the most frequently used brominated flame retardants (BFRs) in the industries nowadays. Despite being listed as persistent organic pollutant (POP), it is still in use until 2025. Because of its bio-accumulative and toxic characteristics, the applicable remediation approach is required. The aim of this study is to identify the microbial community from soil with HBCD degradation ability. The soil suspension and soil samples from Chiang Chun Soil and River Bank Soil showed to degrade HBCD by 60% 4 days after treatment, the debromination ratio was around 60%, and the total HBCD removal ratio reached 70% and 77.9%, respectively. The HBCD debromination metabolites, and oxidation metabolites were identified by GC-MS. The microbial taxonomic diversity was observed with DGGE approach to evaluate the effect of HBCD of microbial community. Bacillus spp. and Clostridium spp. were identified as the dominant microbes in the Chiang Chun Soil, but the amount of Bacillus spp. were showed to be affected by HBCD. In conclusion, HBCD could be removed by the microbial consortium in soil under aerobic culturing condition by various metabolic pathways.

Cingulate gyrus epilepsy: semiology, invasive EEG, and surgical approaches.

OBJECTIVE: The semiology of cingulate gyrus epilepsy is varied and may involve the paracentral area, the adjacent limbic system, and/or the orbitofrontal gyrus. Invasive electroencephalography (iEEG) recording is usually required for patients with deeply located epileptogenic foci. This paper reports on the authors' experiences in the diagnosis and surgical treatment of patients with focal epilepsy originating in the cingulate gyrus. METHODS: Eighteen patients (median age 24 years, range 5-53 years) with a mean seizure history of 23 years (range 2-32 years) were analyzed retrospectively. The results of presurgical evaluation, surgical strategy, and postoperative pathology are reported, as well as follow-up concerning functional morbidity and seizures (median follow-up 7 years, range 2-12 years). RESULTS: Patients with cingulate gyrus epilepsy presented with a variety of semiologies and scalp EEG patterns. Prior to ictal onset, 11 (61%) of the patients presented with aura. Initial ictal symptoms included limb posturing in 12 (67%), vocalization in 5, and hypermotor movement in 4. In most patients (n = 16, 89%), ictal EEG presented as widespread patterns with bilateral hemispheric origin, as well as muscle artifacts obscuring the onset of EEG during the ictal period in 11 patients. Among the 18 patients who underwent resection, the pathology revealed mild malformation of cortical development in 2, focal cortical dysplasia (FCD) Ib in 4, FCD IIa in 4, FCD IIb in 4, astrocytoma in 1, ganglioglioma in 1, and gliosis in 2. The seizure outcome after surgery was satisfactory: Engel class IA in 12 patients, IIB in 3, IIIA in 1, IIIB in 1, and IVB in 1 at the 2-year follow-up. CONCLUSIONS: In this study, the authors exploited the improved access to the cingulate epileptogenic network made possible by the use of 3D electrodes implanted using stereoelectroencephalography methodology. Under iEEG recording and intraoperative neuromonitoring, epilepsy surgery on lesions in the cingulate gyrus can result in good outcomes in terms of seizure recurrence and the incidence of postoperative permanent deficits.

Removal of hexabromocyclododecane by carboxymethyl cellulose stabilized Fe and Ni/Fe bimetallic nanoparticles: The particle stability and reactivity in water.

Aggregation of nanoparticles (NPs) can hinder the degradative reactivity of particles towards organic pollutants as it reduces available surface area for reaction. This limitation may be circumvented by applying dispersant to improve colloidal stability of nanoparticle suspension. This study examined the removal of hexabromocyclododecane (HBCD), a recently listed persistent organic pollutant, by carboxymethylcellulose (CMC) stabilized nanoscale zerovalent iron (CMC-NZVI) and bimetallic Ni/Fe nanoparticles (CMC-Ni/Fe) under the influence of suspension chemistry. The mass-normalized removal rate constants of HBCD by CMC-Ni/Fe NPs increased with lower particle aggregation. However, the coating could introduce diffusion resistance as HBCD diffused through the CMC layer to the Fe surface. The activation energy was estimated to be 26.8 kJ mol-1, indicating the overall reaction process was neither surface-limited nor diffusion-controlled. The reactivity of CMC-Ni/Fe NPs toward HBCD was not affected by aqueous initial pH substantially. Common monoanions (Cl-, NO3-, and HCO3-) generally enhanced HBCD adsorption but diminished its debromination. The removal rate did not differ significantly among the studied monoanions over a concentration of 2.5-10 mM except HCO3-. Overall, CMC coating can stabilize Ni/Fe NPs, increase their adsorption of HBCD, provide buffer pH capacity, and overcome common inhibition effects of anions in water. These findings suggested the high potential of using CMC-Ni/Fe NPs for in-situ remediation.

Neuroprotection in the Acute Stage Enables Functional Recovery Following Repair of Chronic Cervical Root Transection After a 3-Week Delay.

BACKGROUND: Preganglionic cervical root transection (PCRT) is the most severe type of brachial plexus injury. In some cases, surgical procedures must be postponed for ≥3 wk until electromyographic confirmation. However, research works have previously shown that treating PCRT after a 3-wk delay fails to result in functional recovery. OBJECTIVE: To assess whether the immunosuppressive drug sirolimus, by promoting neuroprotection in the acute phase of PCRT, could enable functional recovery in cases of delayed repair. METHODS: First, rats received a left 6th to 8th cervical root transection, after which half were administered sirolimus for 1 wk. Markers of microglia, astrocytes, neurons, and autophagy were assessed at days 7 and 21. Second, animals with the same injury received nerve grafts, along with acidic fibroblast growth factor and fibrin glue, 3 wk postinjury. Sirolimus was administered to half of them for the first week. Mechanical sensation, grasping power, spinal cord morphology, functional neuron survival, nerve fiber regeneration, and somatosensory-evoked potentials (SSEPs) were assessed 1 and 23 wk postinjury. RESULTS: Sirolimus was shown to attenuate microglial and astrocytic proliferation and enhance neuronal autophagy and survival; only rats treated with sirolimus underwent significant sensory and motor function recovery. In addition, rats who achieved functional recovery were shown to have abundant nerve fibers and neurons in the dorsal root entry zone, dorsal root ganglion, and ventral horn, as well as to have SSEPs reappearance. CONCLUSION: Sirolimus-induced neuroprotection in the acute stage of PCRT enables functional recovery, even if surgical repair is performed after a 3-wk delay.

Biodegradation of hexabromocyclododecane by Rhodopseudomonas palustris YSC3 strain: A free-living nitrogen-fixing bacterium isolated in Taiwan.

The persistent organic pollutant, brominated flame retardant, hexabromocyclododecane (HBCD), identified as an emerging contaminant has been detected in various environmental matrix. The increased level of this toxic organic compound in the environment has been associated with serious human health risks. The results obtained from this study revealed that various Rhodopseudomonas palustris strains isolated from paddy soil in Taiwan possessed good HBCD biodegradation capability when they were cultured aerobically. Among these strains, YSC3 was considered as one of the most potential isolates for HBCD degradation. The optimum HBCD biodegradation occurred at neutral pH and at 35 °C in all our pH and temperature tests at an initial HBCD concentration of 1 ppm. HBCD degradation kinetics generally decreased with the increase of initial HBCD concentration. The study also suggested that the cultivation temperature played a vital role on YSC3 for its initiation of cellular HBCD degradation. The relative-molar ratio of the released bromide ions during the biodegradation of HBCD was observed in the range between 1 and 3.5, suggesting that the debromination reactions occurred. Concomitant with the loss of HBCD, there was a concurrent production of two metabolites, pentabromocyclododecanol and pentabromocyclododecene, which were determined by liquid chromatography and mass spectrometry techniques. On the basis of the obtained results, the possible biodegradation pathways were also proposed in this study.

Procedure-Related Temporal Infarct After Retractorless Transsylvian Selective Amygdalohippocampectomy and Impact on 2-Year Epilepsy Outcome.

BACKGROUND: Selective amygdalohippocampectomy (SAH) is designed to treat patients with mesial temporal lobe epilepsy (MTLE). OBJECTIVE: To determine the volume and impact of temporal lobe infarction after retractorless transsylvian SAH (en bloc resection of the hippocampus) that have not been reported. METHODS: A retrospective analysis of patients treated with retractorless transsylvian SAH. Infarctions were detected by magnetic resonance imaging (MRI) within the first week after the operation. Neuropsychological testing was performed preoperatively and 6 mo later. Seizure outcome was evaluated 2 yr after epilepsy surgery. RESULTS: Between 2010 and 2014, a total of 30 patients were included in this study. Analysis of postoperative MRI showed the following: (1) mean removal volume of the hippocampus-parahippocampus was 5.72 cm3, and (2) mean volumes of temporal and insular infarctions were 1.71 and 0.25 cm3, respectively. Twenty-five patients (83.3%) were free of disabling seizures (Engel class I) at 2 yr of outcome. Neuropsychological testing revealed improvement in Perceptual Organization Index (P = .036) and verbal paired associates II (P = .014) after the operation. Neither infarction volume nor removal volume was related to epilepsy outcome in linear regression model. CONCLUSION: Transsylvian SAH has comparable seizure outcomes but bears inherent risks of vasospasm/vascular injury. Immediate postoperative small infarction volume around resection cavity or along surgical corridor was noticed after retractorless transsylvian SAH, which did not cause neuropsychological deteriorations, in contrast to previous study with the use of self-sustaining rigid retraction system. Further study should be performed to compare procedure-related infarctions and their impacts on neuropsychological outcomes in different selective approaches.

Temporal and spatial surveys of polybromodiphenyl ethers (PBDEs) contamination of soil near a factory using PBDEs in northern Taiwan.

Polybrominated diphenyl ethers (PBDEs), previously commonly used as flame retardants, should be monitored in the environment since some are listed as persistent organic pollutants. A contaminated site near a northern Taiwan factory using decabrominated diphenyl ether (deca-BDE) was identified based on a vegetable PBDEs monitoring project in 2013. The subsequent spatial and temporal survey of that contaminated site shows the contamination ingredients in soils were close to ones used by the factory, indicating that contamination was from the factory, possibly through an exhaust vent. The average concentration of deca-BDE in the main contaminated soil was 615 µg/kg d. w. (dry weight) soil in 2015, slightly decreasing to 604 µg/kg d. w. soil in 2016, increasing to 844 µg/kg d. w. soil in 2017, and then slightly decreasing to 670 µg/kg d. w. soil in 2018. The slight change of deca-BDE and the minor change in low brominated congener level indicate a low degradation rate. The contamination of peripheral sites was around 5000 µg/kg d. w. soil for one PBDEs sampling site that was higher than those around or within the main contaminated farm, indicating serious pollution. Concentrations of PBDEs in different soil depths show that depth 2-15 cm accounted for the greatest PBDEs accumulation, indicating that deca-BDE pollution had been present over time and transported into deeper soil. There can be PBDEs uptake by crops consumed by humans, as shown in our previous studies, so continuous monitoring of PBDEs in this site is important and treatments should be established urgently.

Using high-throughput transcriptome sequencing to investigate the biotransformation mechanism of hexabromocyclododecane with Rhodopseudomonas palustris in water.

We discovered one purple photosynthetic bacterium, Rhodopseudomonas palustris YSC3, which has a specific ability to degrade 1, 2, 5, 6, 9, 10-hexabromocyclododecane (HBCD). The whole transcriptome of R. palustris YSC3 was analyzed using the RNA-based sequencing technology in illumina and was compared as well as discussed through Multi-Omics onLine Analysis System (MOLAS, http://molas.iis.sinica.edu.tw/NTUIOBYSC3/) platform we built. By using genome based mapping approach, we can align the trimmed reads on the genome of R. palustris and estimate the expression profiling for each transcript. A total of 341 differentially expressed genes (DEGs) in HBCD-treated R. palustris (RPH) versus control R. palustris (RPC) was identified by 2-fold changes, among which 305 genes were up-regulated and 36 genes were down-regulated. The regulated genes were mapped to the database of Gene Ontology (GO) and Genes and Genomes Encyclopedia of Kyoto (KEGG), resulting in 78 pathways being identified. Among those DEGs which annotated to important functions in several metabolic pathways, including those involved in two-component system (13.6%), ribosome assembly (10.7%), glyoxylate and dicarboxylate metabolism (5.3%), fatty acid degradation (4.7%), drug metabolism-cytochrome P450 (2.3%), and chlorocyclohexane and chlorobenzene degradation (3.0%) were differentially expressed in RPH and RPC samples. We also identified one transcript annotated as dehalogenase and other genes involved in the HBCD biotransformation in R. palustris. Furthermore, the putative HBCD biotransformation mechanism in R. palustris was proposed.

Sorption of organic compounds to two diesel soot black carbons in water evaluated by liquid chromatography and polyparameter linear solvation energy relationship.

Substantial variability in sorption capacity of black carbon (BC) has been a major challenge for accurate fate and risk assessment of organic pollutants in soils and sediments. 16 model organic sorbates (logKOW = 0.38-4.21) encompassing diverse chemical functionalities were used to probe the sorption capacity of two diesel soot samples representative of graphitic BC (BC1, specific surface area (SSA) = 87 m2/g) and amorphous, oxygenated BC (BC2; SSA = 3.6 m2/g). The BC-water sorption coefficients (logKBC) of the model sorbates were determined using reversed-phase liquid chromatography (RP-LC) on soot-filled columns. It was found that mass-based logKBC's of BC1 (1.64-3.66 L/kgBC) exceeded those of BC2 (0.68-3.48 L/kgBC) consistently for all model sorbates. However, area-normalized logKBC's of BC2 were larger than those of BC1, suggesting that the overall sorption was more favored on the oxygenated sorbent per area basis. Linear solvation energy relationships (LSERs) for sorption onto BC1 and BC2 were found to be logKBC = (2.49 ±â€¯0.65)E + (-2.71 ± 0.88)S + (1.17 ± 0.46)A + (2.52 ± 0.34)V and logKBC = (1.12 ±â€¯0.39)E + (-1.68 ± 0.32)S + (-3.70 ± 0.57)B + (4.37 ± 0.38)V + (-1.51 ± 0.22), respectively. The LSERs indicated that sorption onto soot was generally enhanced with increasing non-specific van der Waals and decreasing cavitation cost (i.e., eE, sS, and vV terms). The logKBC difference between BC1 and BC2, ΔlogKBC, appeared to be correlated with the H-bonding capacity of the sorbates but not logKOW. Analysis of literature and experimental logKBC's revealed that logKBC and logSSA across different types of BC (i.e., soot, char, charcoal, activated carbon) were linearly correlated for benzene and toluene (r2 = 0.88-0.91). This work illustrates the utility of RP-LC in determining the sorption coefficients of high-capacity sorbents and suggests the possibility of a unified sorption model for the continuum of black carbon.