Characterizing the photodegradation-induced release of volatile organic compounds from bottled water containers

While plastic water bottles are known to potentially release various volatile organic compounds (VOCs) when exposed to light, existing knowledge in this field remains limited. In this study, we systematically examined the composition, yield, and toxicity of VOCs released from six plastic containers obtained from different continents under UV-A and solar irradiation. After light exposure, all containers released VOCs, including alkanes, alkenes, alcohols, aldehydes, carboxylic acids, aromatics, etc. The 1#, 3#, 4#, 5#, and 6# containers exhibited 35, 32, 19, 24 and 37 species of VOCs, respectively. Specifically, the 2# container released 28 and 32 series of VOCs after 1-day (short-term) and 7-day (long-term) UV-A irradiation, respectively, compared to 30 and 32 species under solar irradiation. Over half of the VOCs identified were oxidized compounds alongside various short-chain hydrocarbons. Significant differences in VOC compositions among the containers were observed, potentially originating from light-induced aging and degradation of the polyethylene terephthalate structure in the containers. Toxicological predictions unveiled distinctive toxic characteristics of VOCs from each container. For example, among the various VOCs produced by the 2# container, straight-chain alkanes like n-hexadecane (544-76-3) were identified as the most toxic compounds. After long-term irradiation, the yield of these toxic VOCs from the 2# container ranged from 0.11 ng/g to 0.79 ng/g. Considering the small mass of a single bottle, the volatilization of VOCs from an individual container would be insignificant. Even after prolonged exposure to light, the potential health risks associated with inhaling VOCs when opening and drinking bottled water appear manageable.

Microplastics and volatile organic compounds released from face masks after disinfection: Layers and materials differences

Effective disinfection methods are critical for ensuring the reusability of masks, yet these methods may inadvertently introduce health concerns associated with microplastics (MPs) and volatile organic compounds (VOCs). This study investigated the impact of ultraviolet germicidal irradiation (UVGI) and sodium hypochlorite (NaClO) bleaching on mask filter layers composed of four distinct materials. Our results revealed that UVGI induced more pronounced damage compared to bleaching, leading to the significant release of both MPs and VOCs. After UVGI treatment at conventional disinfection doses, meltblown (MB) fabrics released MPs reaching 864 ± 182 μg/g (92 ± 19 particles/g). For all filter layers, the quantity of released MPs followed the order: MB > HDPE>PU ≈ NW. These MPs were identified as degraded debris from the mask filter layers. The specific VOCs generated varied depending on the material composition. Non-woven (NW) and MB fabrics, both comprised of polypropylene, predominantly produced various branched aliphatic hydrocarbons and their derivative oxides. The cotton-like fabric, composed of high-density polyethylene, primarily emitted different linear aliphatic hydrocarbons and oxygenates. In contrast, the polyurethane filter layer of reusable masks released aromatic compounds, nitrogenous compounds, and their oxidation products. The formation of VOCs was primarily attributed to bond breakage and oxidative damage to the filter structure resulting from the disinfection process. In summary, as UVGI induced higher yields of MPs and VOCs compared to bleaching, the latter would be a safer option for mask disinfection.

Effective green treatment of sewage sludge from Fenton reactions: Utilizing MoS2 for sustainable resource recovery

Effectively managing sewage sludge from Fenton reactions in an eco-friendly way is vital for Fenton technology's viability in pollution treatment. This study focuses on sewage sludge across various treatment stages, including generation, concentration, dehydration, and landfill, and employs chemical composite MoS2 to facilitate green resource utilization of all types of sludge. MoS2, with exposed Mo4+ and low-coordination sulfur, enhances iron cycling and creates an acidic microenvironment on the sludge surface. The MoS2-modified iron sludge exhibits outstanding (>95%) phenol and pollutant degradation in hydrogen peroxide and peroxymonosulfate-based Fenton systems, unlike unmodified sludge. This modified sludge maintains excellent Fenton activity in various water conditions and with multiple anions, allowing extended phenol degradation for over 14 d. Notably, the generated chemical oxygen demand (COD) in sludge modification process can be efficiently eliminated through the Fenton reaction, ensuring effluent COD compliance and enabling eco-friendly sewage sludge resource utilization.

Interfacial quantum chemical characterization of aromatic organic matter adsorption on oxidized microplastic surfaces

Examining the adsorption efficiency of individual contaminants on microplastics (MPs) is resource-intensive and time-consuming. To address this challenge, combined laboratory adsorption experiments with model simulations were performed to investigate the adsorption capacities and mechanisms of MPs before and after aging. Our adsorption experiments revealed that aged polyethylene (PE) and polyvinyl chloride (PVC) MPs exhibited increased adsorption capacity for benzene, phenol, and naphthalene. Additionally, density functional theory (DFT) simulations provided insights into changes in adsorption sites, adsorption energy, and charge density on MPs. The π bond of the benzene ring emerged as a pivotal factor in the adsorption process, with van der Waals forces exerting dominant influence. For instance, the adsorption energy of benzene on pristine PE was -0.01879 eV. When oxidized groups, such as hydroxyl, carbonyl, and carboxyl, on the surface of aged PE became the adsorption sites, the adsorption energy increased to -0.06976, -0.04781, and -0.04903 eV, respectively. Regions with unoxidized functional groups also exhibited higher adsorption energies than pristine PE. These results indicated that aged PE had a stronger affinity for benzene compared to pristine PE, enhancing its adsorption. Charge density difference and energy density of states corroborated this observation, revealing larger π-bond charge accumulation areas for benzene on aged PE, suggesting stronger dipole interactions and enhanced adsorption. Similar trends were observed for phenol and naphthalene. In summary, the DFT calculations aligned with the adsorption experiment findings, confirming the effectiveness of simulation methods in predicting changes in the adsorption performance of aged MPs.

Gaseous products generated from polyethylene and polyethylene terephthalate during ultraviolet irradiation: Mechanism, pathway and toxicological analyses

The generation of various degradation products from microplastics (MPs) has been confirmed under ultraviolet (UV) irradiation. The gaseous products, primarily volatile organic compounds (VOCs), are usually overlooked, leading to potential unknown risks to humans and the environment. In this study, the generation of VOCs from polyethylene (PE) and polyethylene terephthalate (PET) under UV-A (365 nm) and UV-C (254 nm) irradiation in water matrixes were compared. More than 50 different VOCs were identified. For PE, UV-A-derived VOCs mainly included alkenes and alkanes. On this basis, UV-C-derived VOCs included various oxygen-containing organics, such as alcohols, aldehydes, ketones, carboxylic acid and even lactones. For PET, both UV-A and UV-C irradiation induced the generation of alkenes, alkanes, esters, phenols, etc., and the differences between these two reactions were insignificant. Toxicological prioritization prediction revealed that these VOCs have diverse toxicological profiles. The VOCs with the highest potential toxicity were dimethyl phthalate (CAS: 131-11-3) from PE and 4-acetylbenzoate (3609-53-8) from PET. Furthermore, some alkane and alcohol products also presented high potential toxicity. The quantitative results indicated that the yield of these toxic VOCs from PE could reach 10² μg g^-1 under UV-C treatment. The degradation mechanisms of MPs included direct scission by UV irradiation and indirect oxidation induced by diverse activated radicals. The former mechanism was dominant in UV-A degradation, while UV-C included both mechanisms. Both mechanisms contributed to the generation of VOCs. Generally, MPs-derived VOCs can be released from water to the air after UV irradiation, posing a potential risk to ecosystems and human beings, especially for UV-C disinfection indoors in water treatments.

Modifications to microplastics by potassium ferrate(VI): impacts on sorption and sinking capability in water treatment

Pre-treatment (oxidation) may induce potential modifications to microplastics (MPs), further affecting their behaviors and removal efficiency in drinking water treatment plants. Herein, potassium ferrate(VI) oxidation was tested as a pre-treatment for MPs with four polymer types and three sizes each. Surface oxidation occurred with morphology destruction and oxidized bond generation, which were prosperous under low acid conditions (pH 3). As pH increased, the generation and attachment of nascent state ferric oxides (Fe_xO_x) gradually became dominant, making MP-Fe_xO_x complexes. These Fe_xO_x were identified as Fe(III) compounds, including Fe₂O₃ and FeOOH, firmly attaching to the MP surface. Using ciprofloxacin as the targeted organic contaminant, the presence of Fe_xO_x enhanced MP sorption dramatically, e.g., the kinetic constant K_f of ciprofloxacin raised from 0.206 (6.5 μm polystyrene) to 1.062 L g^-1 (polystyrene-Fe_xO_x) after oxidation at pH 6. The sinking performance of MPs was enhanced, especially for small MPs (< 10 μm), which could be attributed to the increasing density and hydrophilicity. For instance, the sinking ratio of 6.5 μm polystyrene increased by 70% after pH 6 oxidation. In general, ferrate pre-oxidation possesses multiple enhanced removals of MPs and organic contaminants through adsorption and sinking, reducing the potential risk of MPs.

Volatile organic compounds generation pathways and mechanisms from microplastics in water: Ultraviolet, chlorine and ultraviolet/chlorine disinfection

Disinfection in water treatments induces microplastics (MPs) to produce various derivative products, among which the volatile organic compounds (VOCs) are still poorly understood. Ultraviolet (UV), chlorine and UV/chlorine disinfections were used to treat polypropylene (PP), polystyrene (PS) and polyvinylchloride (PVC) in this study. Modifications were observed on the MP surfaces, including melting, cracks, folds, and even forming oxygen-containing structures, resulting in the release of a diversity of VOCs. The polymer types of MPs influenced the VOCs characteristics. PP released alkanes, alkenes and aldehydes, while PVC released alkanes, alkenes and halogenated hydrocarbons. VOCs from PS were dominated by unique aromatic alkanes, alkenes and aldehydes. These derived VOCs are generated during different disinfections with distinct mechanisms. UV-C at 254 nm induced direct scission and radical oxidation on MPs. The derived VOCs were mainly bond-breaking fragments. Chlorination relied on HOCl/OCl^- electrophilic reactions, resulting fewer VOCs since C-C skeleton MPs have strong resistance to electrophilic reactions. UV/chlorination promotes the generation of chlorine radicals and hydroxyl radicals, thereby causing oxidative damage. Various oxidized VOCs, such as benzaldehyde and acetophenone, were formed. The disinfection reactions can produce various VOCs from MPs, posing potential risks to the ecological environment and human beings.

Modifications of microplastics in urban environmental management systems: A review

Microplastics (MPs) are a worldwide environmental pollution issue. Besides the natural environmental stresses, various treatments in urban environmental management systems induce modifications on MPs, further affecting their environmental behavior. Investigating these modifications and inherent mechanisms is crucial for assessing the environmental impact and risk of MPs. In this review, up-to-date knowledge regarding the modifications of MPs in urban environmental management systems was summarized. Variations of morphology, chemical composition, hydrophilicity and specific surface area of MPs were generalized. The aging and degradation of MPs during drinking water treatment, wastewater treatment, sewage sludge treatment and solid waste treatment were investigated. A high abundance of MPs occurred in sewage sludge and aging solid waste, while digestion and composting contributed to significant decomposition and reduction of MPs. These treatments have become converters for MPs before entering the environment. Several novel technologies for MPs removal were listed; However, no appropriate methods can be put into actual application by now, except the membrane separation. The corresponding effects of degradation on the behaviors of MPs, including adsorption, sinking and contaminant leakage, were discussed. Finally, three priorities for research were proposed. This critical review provides viewpoints and references for risk evaluation of MPs after treatments in urban environmental management systems.

Modifications of ultraviolet irradiation and chlorination on microplastics: Effect of sterilization pattern

Chlorination and ultraviolet disinfection in drinking water treatment plants (DWTPs) may be highly destructive for microplastics (MPs). Investigating the effect of sterilization patterns on MPs behavior modifications can provide useful information to evaluate their potential risk to drinking water safety. In this study, aged polyethylene (PE), polyethylene terephthalate (PET), polystyrene (PS) and polyvinyl chloride (PVC) were applied, and five well-designed sterilization patterns with low and high doses disinfection were performed. Especially, a combining sterilization pattern including ultraviolet disinfection, low-dose chlorination and high-dose chlorination was designed to simulate the actual disinfection processes in environmental engineering systems. Different sterilization patterns contributed various chlorinated and oxidized modifications on the MPs surface, resulting in distinct effects on their sinking and adsorption performance. After combining sterilization (180 mJ cm^-2 UV-C irradiation +9675 mg min L^-1 chlorination), the adsorption capacities of ciprofloxacin by PET and PVC were slightly improved, and the one by PS was inhibited. Yet, PET, PVC and PS tend to sink (>95%) after this combining sterilization, implying that these MPs would be retained in DWTPs or water supply pipes. For PE, even though it maintained floating on water, its adsorption of ciprofloxacin was inhibited by combining sterilization (K_f reduced from 0.142 L g^-1 to 0.069 L g^-1). In general, multiple sterilization patterns can enhance the sinking and inhibit the adsorption performance of MPs, reducing their potential to become vectors of organic contaminants and risk to drinking water users.

Surface characteristic and sinking behavior modifications of microplastics during potassium permanganate pre-oxidation

Microplastics (MPs) occur in the source water of worldwide drinking water treatment plants (DWTPs). Pre-oxidation treatments become the initial stage for MPs treatment in DWTPs. Investigating the modifications of MPs after pre-oxidations is important to understand their fate in DWTPs. In this study, potassium permanganate oxidation (PPO) was applied to treat four high abundant MPs in DWTPs, including polyethylene (PE), polyethylene terephthalate (PET), polyvinylchloride (PVC) and polystyrene (PS). Influences of polymer types, sizes and pH were considered. After 10 mg L^-1 PPO, only slight corrosions were observed on all MPs. Whereas, the appearances of O-Mn spectrum and the observation of nano-scale particles indicated the generation of nascent state Mn-oxides (MnO₂) on MPs surface. This adhesion of MnO₂ contributed to increasing density and hydrophilicity. As a result, the sinking performance of MPs was enhanced, e.g. the sinking ratio of 6.5 µm MPs increased 30% (PET), 20% (PVC) and 30% (PS) compared with pristine ones upon pH 7 PPO. These results implied that the practical PPO can enhance the sinking behavior of MPs. Of note, PE seems to be persistent and requires special concern.

Enhancement of aqueous stability of NH2-MIL-101(Fe) by hydrophobic grafting post-synthetic modification

The development of water-stable metal-organic frameworks is a critical issue for their photocatalysis applications in water treatment. A phenyl-ethyl side chain with low surface energy was grafted into NH₂-MIL-101(Fe) through a post-synthetic modification (PSM) method. As a result, a novel MIL-101(Fe)-1-(4-(ethyl)phenyl)urea (named MIL-101(Fe)-EPU) was synthesized. Basic morphology, crystal structure, and chemical bond features of MIL-101(Fe)-EPU were retained after PSM. Nitrogen X-ray photoelectron spectroscopy analysis confirmed the successful introduction of the phenyl-ethyl side chain, and this transformation increased its hydrophobicity and water stability. Contact angles of MIL-101(Fe)-EPU to water raised from 59.6 to 140.4°. And its structure maintained intact after 72 h water exposure, indicating higher stability than parent NH₂-MIL-101(Fe). In the photocatalysis reaction with visible light and oxidant donor (H₂O₂), MIL-101(Fe)-EPU demonstrated a degradation efficiency of tetrabromobisphenol A with a reaction rate at 0.0313 min^-1. The predominant reaction mechanism was OH·oxidation. The acid condition was beneficial for this photocatalysis reaction and high stability was observed. Besides, photocatalysis efficiency, crystal structure, and chemical structures were all retained in different actual water mediums, suggesting high adaptability of MIL-101(Fe)-EPU. In general, hydrophobic group grafting using a PSM method endows MIL-101(Fe)-EPU the potentiality as photocatalyst for organic contaminant elimination from water.

Generation of hydroxyl radicals by metal-free bifunctional electrocatalysts for enhanced organics removal

Low yields of H₂O₂ and a narrow range of appropriate pH values have been two major drawbacks for electro-Fenton (EF) process. Herein, metal-free electrochemical advanced oxidation processes (EAOPs) were developed with nitrogen and sulfur co-doped electrochemically exfoliated graphene (N, S-EEGr) electrocatalysts, which was confirmed as an outstanding bifunctional catalyst for synchronous generation and activation of H₂O₂ via (2 + 1) e^- consecutive reduction reactions. Specifically, two elements (N, S) in metal-free N, S-EEGr-CF cathode synergize to promote the formation of H₂O₂ followed by its activation. With N, S-EEGr-CF cathode, phenol of initial 50 mg L^-1 could be effectively removed within pH 3-11 and 6.25 mA cm^-2, and 100% removal efficiency could be achieved within 15-min even at neutral pH. The pseudo-first-order rate constant for phenol removal in metal-free EAOPs with N,S-EEGr-CF at neutral pH was 10 times higher than that with EF process. Detection of active species, coupled with decay kinetics with specific trapping agents, confirmed that OH was the dominant oxidizing species promoting removal efficiencies of organics (phenol, antibiotics and dyes) at pH 3 and pH 7. In the actual wastewater treatment, the synergistic effect of bifunctional catalyst would also be used for improving the degradation efficiency of organics. Thus, the metal-free EAOPs with N,S-EEGr-CF cathode may serve as an alternative in wastewater treatment with a broadened range of solution pH values and avoiding Fe²⁺ (catalyst) addition.

A two-in-one Janus NIR-II AIEgen with balanced absorption and emission for image-guided precision surgery

Fluorescence imaging in the near-infrared II (NIR-II, 1000-1700 nm) region opens up new avenues for biological systems due to suppressed scattering and low autofluorescence at longer-wavelength photons. Nonetheless, the development of organic NIR-II fluorophores is still limited mainly due to the shortage of efficient molecular design strategy. Herein, we propose an approach of designing Janus NIR-II fluorophores by introducing electronic donors with distinct properties into one molecule. As a proof-of-concept, fluorescent dye 2 TT-m, oC6B with both twisted and planar electronic donors displayed balanced absorption and emission which were absent in its parent compound. The key design strategy for Janus molecule is that it combines the merits of intense absorption from planar architecture and high fluorescence quantum yield from twisted motif. The resulting 2 TT-m, oC6B nanoparticles exhibit a high molar absorptivity of 1.12 ⨯104 M-1 cm-1 at 808 nm and a NIR-II quantum yield of 3.7%, displaying a typical aggregation-induced emission (AIE) attribute. The highly bright and stable 2 TT-m, oC6B nanoparticles assured NIR-II image-guided cancer surgery to resect submillimeter tumor nodules. The present study may inspire further development of molecular design philosophy for highly bright NIR-II fluorophores for biomedical applications.

Metabolic network and recovery mechanism of Escherichia coli associated with triclocarban stress

Although the toxicity of triclocarban at molecular level has been investigated, the metabolic networks involved in regulating the stress processes are not clear. Whether the cells would maintain specific phenotypic characteristics after triclocarban stress is also needed to be clarified. In this study, Escherichia coli was selected as a model to elucidate the cellular metabolism response associated with triclocarban stress and the recovery metabolic network of the triclocarban-treated cells using the proteomics and metabolomics approaches. Results showed that triclocarban caused systematic metabolic remodeling. The adaptive pathways, glyoxylate shunt and acetate-switch were activated. These arrangements allowed cells to use more acetyl-CoA and to reduce carbon atom loss. The upregulation of NH₃-dependent NAD⁺ synthetase complemented the NAD⁺ consumption by catabolism, maintaining the redox balance. The synthesis of 1-deoxy-D-xylulose-5-phosphate was suppressed, which would affect the accumulation of end products of its downstream pathway of isoprenoid synthesis. After recovery culture for 12 h, the state of cells returned to stability and the main impacts on metabolic network triggered by triclocarban have disappeared. However, drug resistance caused by long-term exposure to environmentally relevant concentration of triclocarban is still worthy of attention. The present study revealed the molecular events under triclocarban stress and clarified how triclocarban influence the metabolic networks.

Ultraviolet-C and vacuum ultraviolet inducing surface degradation of microplastics

Wastewater treatment plants (WWTPs) are considerable microplastics (MPs) contributors to environmental waters. Knowledge about the MPs degradation process under ultraviolet irradiation was crucial to understanding the fate of MPs during and after water disinfection. In this study, surface alternations of polystyrene (PS), polyethylene (PE), polyvinylchloride (PVC) and polyethylene terephthalate (PET) under 254 nm (UV-C) and 185/254 nm (vacuum ultraviolet, VUV) irradiation were estimated. One-way treatment of MPs by UV or VUV with the recommended dose for WWTPs (USEPA, ~180 mJ cm^-2) had little effect. In contrast, excessive exposure under twenty-times doses irradiation (3600 mJ cm^-2) resulted in significant alternations on surface morphology, chemical feature and hydrophobicity. Noticeably morphology alterations, including cracks, wrinkles and protuberances, were observed for PS, PVC and PET, while PE was relatively resistant. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy revealed that UV irradiation induced cleavage of chemical bonds. Besides, simultaneous radical oxidation was predominant during VUV treatment, which contributed to the increasing generation of oxygen bonds, such as CO and CO, on all MPs surfaces. Drastic decreases of contact angle (> 20°) were observed for PS, PVC and PET even after 180 mJ cm^-2 UV irradiation, indicating the UV disinfection in WWTPs can easily change their surface hydrophobicity. All these alternations weakened the adsorption capacity of non-polar benzene and polar ciprofloxacin on MPs. Generally, regular dose UV and VUV irradiation in water treatment disinfection can only induce slight effects on MPs surface characteristics and adsorption performance, while extreme dose irradiation can induce a potential reducing risk of organic contaminants migration along with MPs.

Molecular response mechanism in Escherichia coli under hexabromocyclododecane stress

The effects of hexabromocyclododecane (HBCD) on the relationship between physiological responses and metabolic networks remains unclear. To this end, cellular growth, apoptosis, reactive oxygen species, exometabolites and the proteome of Escherichia coli were investigated following exposure to 0.1 and 1 μM HBCD. The results showed that although there were no significant changes in the pH value, apoptosis and reactive oxygen species under HBCD stress, cell growth was inhibited. The metabolic network formed by glycolysis, oxidative phosphorylation, amino acids biosynthesis, membrane proteins biosynthesis, ABC transporters, glycogen storage, cell recognition, compound transport and nucleotide excision repair was disrupted. Cell chemotaxis and DNA damage repair were the effective approaches to alleviate HBCD stress. This work improves our understanding of HBCD toxicity and provides insight into the toxicological mechanism of HBCD at the molecular and network levels.

Two-in-one ultraviolet persistent luminescent catalyst suitable for high concentration photodegradation

Heterogeneous photodegradation is limited at high catalyst concentrations because of the scattering and reflection of the particulate catalysts. To further improve the efficiency of photodegradation and the use of space in photoreactors at high catalyst concentrations, Ga³⁺ was doped into Zn₂SiO₄ to introduce positively charged traps to capture photo-generated electrons and, thus, achieve long lifetime charge separation. In this strategy, Zn₂SiO₄:Ga³⁺ was obtained as a two-in-one (persistent luminescence and catalysis) persistent photocatalyst for the efficient photodegradation of a household insecticide, permethrin. Zn₂SiO₄:Ga³⁺ possesses an UV afterglow property. Zn₂SiO₄:Ga³⁺ can store UV irradiation energy as long lifetime separated electron/hole pairs at the solution surface and then deliver this energy deep into the bulk of the solution, thus taking full advantage of the photoreactor. High catalyst concentrations are preferred for improving the persistent photodegradation efficiency. The UV persistent photocatalytic strategy and the persistent Zn₂SiO₄:Ga³⁺ catalyst are significant for designing fast photocatalytic reactors with high catalyst concentrations.

Degradation of 1H-benzotriazole using vacuum ultraviolet: a prospective treatment method for micro-pollutants

Benzotriazoles (BTs) attract increasing concerns because of abundant presence in environmental water bodies. In this study, degradation of 1H-benzotriazole (1H-BT) was performed by a customized vacuum ultraviolet (VUV) device emitting 185 + 254 nm (VUV/UV-C) irradiation. Degradation of 1H-BT presented an apparent rate constant reached 8.17 × 10^-4 s^-1. Degradation mechanisms included 185 + 254 nm photodegradation and radical reaction. The later one may be the predominant one, which presented a k_·OH-1H-BT at (7.3 ± 0.8) × 10⁹ M^-1 s^-1. Effects of anions revealed that VUV interception and radical trapping were the dominant restraining factors. Degradation of 1H-BT can be attributed to VUV induced radical-based oxidation. Radical-induced addition, substitution and fracture generated abundant hydroxylated and open-loop products during 10-45 min. Identification using reactive oxygen species and apoptosis in Escherichia coli was conducted. Variations of these two indicators revealed that the incomplete degradation products presented higher toxicities than 1H-BT, and a further mineralization reduced their toxicities. In the pure water solution with little impurities, VUV can induce efficient degradation of 1H-BT, suggesting its potential for eliminating and detoxifying MPs.

Enhanced photocatalysis using metal-organic framework MIL-101(Fe) for organophosphate degradation in water

Metal-organic frameworks (MOFs) are attractive novel classes of porous materials with diverse potentiality and easily tailored structures. It is desirable to evaluate the performance of MOFs as photocatalysts for organic contaminant removal in aqueous matrixes. In this study, iron-based MIL-101(Fe) was synthesized and a photo-Fenton reaction system (multiple wavelength light + MIL-101(Fe) + H₂O₂) was developed for elimination of tris(2-chloroethyl) phosphate (TCEP). Degradation pattern of TCEP followed an S-shape curve, which included a slow induction period and a rapid radical oxidation process. Transport of reactants into MIL-101(Fe) and the activation of electron transport within Fe-O clusters of MIL-101(Fe) may be the dominant mechanisms in the induction period, while a pseudo-first-order kinetics was observed in the hydroxyl radical oxidation process. Removal efficiencies in these two stages highly depended on the reaction conditions. Irradiation at 420 nm and acid condition were conductive, while high temperature and high [H₂O₂]:[MIL-101(Fe)] mass ratio accelerated the reaction. Before complete mineralization, eleven degradation products were generated, and the dominant degradation pathways included cleavage, hydroxylation, carbonylation, and carboxylation. Under acid condition (pH = 3), only 1% mass loss was observed after 60-min reaction, but the iron leakage was aggravated when pH increased. Furthermore, this MOF-photo-Fenton system demonstrated a robust performance on TCEP degradation in actual wastewater matrixes under acid condition. Generally, the MOF-photo-Fenton system is a potential technology for elimination of organic pollutants in aqueous solution.

Metabolic and proteomic mechanism of bisphenol A degradation by Bacillus thuringiensis

Bisphenol A (BPA) is a worldwide, widespread pollutant with estrogen mimicking and hormone-like properties. To date, some target biomolecules associated with BPA toxicity have been confirmed. The limited information has not clarified the related metabolism at the pathway and network levels. To this end, metabolic and proteomic approaches were performed to reveal the synthesis of phospholipids and proteins and the metabolic network during the BPA degradation process. The results showed that the degradation efficiency of 1 μM of BPA by 1 g L^-1 of Bacillus thuringiensis was up to 85% after 24 h. During this process, BPA significantly changed the membrane permeability; altered sporulation, amino acid and protein expression, and carbon, purine, pyrimidine and fatty acid metabolism; enhanced C14:0, C16:1ω7, C18:2ω6, C18:1ω9t and C18:0 synthesis; and increased the trans/cis ratio of C18:1ω9t/C18:1ω9c. It also depressed the spore DNA stability of B. thuringiensis. Among the 14 upregulated and 7 down-regulated proteins, SasP-1 could be a biomarker to reflect BPA-triggered spore DNA impairment. TpiA, RpoA, GlnA and InfA could be phosphorylated at the active sites of serine and tyrosine. The findings presented novel insights into the interaction among BPA stress, BPA degradation, phospholipid synthesis and protein expression at the network and phylogenetic levels.

Cellular metabolism network of Bacillus thuringiensis related to erythromycin stress and degradation

Erythromycin is one of the most widely used macrolide antibiotics. To present a system-level understanding of erythromycin stress and degradation, proteome, phospholipids and membrane potentials were investigated after the erythromycin degradation. Bacillus thuringiensis could effectively remove 77% and degrade 53% of 1 µM erythromycin within 24 h. The 36 up-regulated and 22 down-regulated proteins were mainly involved in spore germination, chaperone and nucleic acid binding. Up-regulated ribose-phosphate pyrophosphokinase and ribosomal proteins confirmed that the synthesis of protein, DNA and RNA were enhanced after the erythromycin degradation. The reaction network of glycolysis/gluconeogenesis was activated, whereas, the activity of spore germination was decreased. The increased synthesis of phospholipids, especially, palmitoleic acid and oleic acid, altered the membrane permeability for erythromycin transport. Ribose-phosphate pyrophosphokinase and palmitoleic acid could be biomarkers to reflect erythromycin exposure. Lipids, disease, pyruvate metabolism and citrate cycle in human cells could be the target pathways influenced by erythromycin. The findings presented novel insights to the interaction among erythromycin stress, protein interaction and metabolism network, and provided a useful protocol for investigating cellular metabolism responses under pollutant stress.

Efficient Blue to Red Afterglow Tuning in a Binary Nanocomposite Plastic Film

Colorful spectra are important for the diverse applications of persistent phosphors. A color conversion concept is developed to obtain abundant persistent luminescence color by mining capacities of known persistent phosphors with the most efficient persistent properties. Here, SiO₂/Sr₂MgSi₂O₇:Eu,Dy nanoparticles are chosen as a blue persistent luminescence donor nanophosphor, while ultrafine CaAlSiN₃:Eu is utilized as a red conversion phosphor to tune the persistent luminescence spectra from blue to red. The red afterglow emission can persist for more than 5 h. The decay of the red afterglow follows nearly the same kinetics as that of the blue one. Continuous color tuning can be successfully obtained by simply changing the mass ratio of the donor/conversion phosphor pair. This color conversion strategy may be significant in indicating numerous persistent/conversion nanocomposites or nanostructures and advance the development of persistent phosphors in diverse fields which need colorful spectral properties.

Proteome and phospholipid alteration reveal metabolic network of Bacillus thuringiensis under triclosan stress

Triclosan is a common antibacterial agent widely applied in various household and personal care products. The molecule, cell, organ and organism-level understanding of its toxicity pose to some target organisms has been investigated, whereas, the alteration of a single metabolic reaction, gene or protein cannot reflect the impact of triclosan on metabolic network. To clarify the interaction between triclosan stress and metabolism at network and system levels, phospholipid synthesis, and cellular proteome and metabolism of Bacillus thuringiensis under 1μM of triclosan stress were investigated through omics approaches. The results showed that C14:0, C16:1ω7, C16:0 and C18:2ω6 were significantly up-produced, and 19 proteins were differentially expressed. Whereas, energy supply, protein repair and the synthesis of DNA, RNA and protein were down-regulated. PyrH and Eno could be biomarkers to reflect triclosan stress. At network level, the target proteins ACOX1, AHR, CAR, CYP1A, CYP1B1, DNMT1, ENO, HSP60, HSP70, SLC5A5, TPO and UGT expressed in different species shared high sequence homology with the same function proteins found in Homo sapiens not only validated their role as biomarkers but also implied the potential impact of triclosan on the metabolic pathways and network of humans. These findings provided novel insights into the metabolic influence of triclosan at network levels, and developed an omics approach to evaluate the safety of target compound.

UV-driven hydroxyl radical oxidation of tris(2-chloroethyl) phosphate: Intermediate products and residual toxicity

Organophosphorus esters (OPEs) are emerging contaminants widely applied as annexing agents in a variety of industrial products, and they are robust against conventional wastewater treatments. Ultraviolet-driven (UV) radical-based advanced oxidation processes have a potential to become cost-effective treatment technologies for the removal of OPEs in water matrix, but residual and newly generated toxicities of degradation products are a concern. This study is a comprehensive attempt to evaluate UV/H₂O₂ for the degradation of a water dissolved OPE, tris(2-chloroethyl) phosphate (TCEP). In ultrapure water, a pseudo-first order reaction was observed, and the degradation rate constant reached 0.155 min^-1 for 3.5 μM TCEP using 7.0 mW cm^-2 UV irradiation with 44.0 μM H₂O₂. Hydroxyl radicals were involved in the oxidative degradation of TCEP, as demonstrated by the quenching of the degradation reaction in the presences of tertiary butanol or ethanol. High resolution mass spectroscopy data showed a partial transformation of TCEP to a series of hydroxylated and dechlorinated products e.g., C₄H₉Cl₂O₄P, C₆H₁₃Cl₂O₅P and C₂H₆ClO₄P. Based on proteomics data at molecular and metabolic network levels, the toxicity of TCEP products was reduced obviously as the reaction proceeded, which was confirmed by the up-regulated tricarboxylic acid cycle, fatty acid metabolism and amino acid metabolism in Escherichia coli cells exposed to degradation products mixture. In conclusion, incomplete hydroxylation and dechlorination of TCEP likewise are effective for its detoxification, indicating that UV/H₂O₂ can be a promising treatment method for OPEs removal.

[Effects of combination therapy with aspirin, prednisone, and Elevit in patients with unexplained recurrent early pregnancy loss]

Objective: To investigate the effect of triple therapy with aspirin, prednisone and Elevit in patients with unexplained recurrent early pregnancy loss. Methods: From January 1, 2013 to December 31, 2016, a total of 353 women of childbearing age were enrolled in Peking Union Medical College Hospital, including blood, urine and vaginal swabs. One hundred and fifty-five patients were observed normal results of blood test, urine test and vaginal swabs. According to the treatment regimen, 155 patients were divided into two groups, 89 patients (57.42%) treated with (aspirin, prednisone, and Elevit) as experimental group, and the other 66 cases (42.58%) taking folic acid as control group. The fetal bud, fetal heart and neck hyaline layer thickness were examined by ultrasonography at 12 weeks. Visible fetal bud, fetal heart, and nuchal translucency thickness <0.3 cm were used as indicators of successful treatment. t test and χ(2) test were used to analyze and compare the statistical significance of the differences between the two groups of patients, and the Logistic method was used to analyze the data and observe the effect of medication. Results: There were 67 patients successfully treated in the experimental group, the successful rate was 83.75% (67/80), and 33 patients in the control group were successfully treated, the successful rate was 54.10% (33/61). There were significant statistical differences in two groups (P<0.05). Conclusion: The effect of triple therapy with aspirin, prednisone and Elevit in patients with unexplained recurrent early pregnancy loss is significant.

Heterogeneous photocatalysis of tris(2-chloroethyl) phosphate by UV/TiO2: Degradation products and impacts on bacterial proteome

The widespread, persistent and toxic organophosphorus esters (OPEs) have become one category of emerging environmental contaminants. Thus, it is in urgent need to develop a cost-effective and safe treatment technology for OPEs control. The current study is a comprehensive attempt to use UV/TiO₂ heterogeneous photocatalysis for the degradation of a water dissolved OPEs, tris(2-chloroethyl) phosphate (TCEP). A pseudo-first order degradation reaction with a k_obs of 0.3167 min^-1 was observed, while hydroxyl radical may be the dominating reactive oxidative species. As the reaction proceeded, TCEP was transformed to a series of hydroxylated and dechlorinated products. The degradation efficiency was significantly affected by pH value, natural organic matters and anions, implying that the complete mineralization of TCEP would be difficult to achieve in actual water treatment process. Based on the proteomics analysis regarding the metabolism reactions, pathways and networks, the significant activation of transmembrane transport and energy generation in Escherichia coli exposed to preliminary degrading products suggested that they can be transported and utilized through cellular metabolism. Furthermore, the descending trend of stress resistance exhibited that the toxicity of products was obviously weakened as the treatment proceeded. In conclusion, hydroxylation and dechlorination of TCEP with incomplete mineralization were likewise effective for its detoxification, indicating that UV/TiO₂ will be an alternative treatment method for OPEs control.

Ultrathin metal-organic framework membrane production by gel-vapour deposition

Ultrathin, molecular sieving membranes composed of microporous materials offer great potential to realize high permeances and selectivities in separation applications, but strategies for their production have remained a challenge. Here we show a route for the scalable production of nanometre-thick metal–organic framework (MOF) molecular sieving membranes, specifically via gel–vapour deposition, which combines sol–gel coating with vapour deposition for solvent-/modification-free and precursor-/time-saving synthesis. The uniform MOF membranes thus prepared have controllable thicknesses, down to ~17 nm, and show one to three orders of magnitude higher gas permeances than those of conventional membranes, up to 215.4 × 10⁻⁷ mol m⁻² s⁻¹ Pa⁻¹ for H₂, and H₂/C₃H₈, CO₂/C₃H₈ and C₃H₆/C₃H₈ selectivities of as high as 3,400, 1,030 and 70, respectively. We further demonstrate the in situ scale-up processing of a MOF membrane module (30 polymeric hollow fibres with membrane area of 340 cm²) without deterioration in selectivity.

MOF-based membranes have shown great promise in separation applications, but producing thin membranes that allow for high fluxes remains challenging. Here, the authors use a gel–vapour deposition strategy to fabricate composite membranes with less than 20 nm thicknesses and high gas permeances and selectivities.

[Analysis of the influence of iron overload in glucose metabolism in thalassemia major patients]

Objective: This study aimed at determining the characteristics of the glucose homeostasis and its relationship with iron overload of the patients with β-thalassemia major (β-TM). Method: From Sun Yat-sen Memorial Hospital between January 2014 and December 2015, a total of 57 transfusion-dependent β-TM patients with 5-18 years old were enrolled in this study and fasting blood glucose(FBG) and insulin level, serum ferritin (SF), serum iron, transferrin, total iron binding capacity, unsaturated iron binding capacity were determined.Insulin resistance index (IRI), insulin sensitivity index and β-cell function index (BFI) were also estimated. Besides, in 36 patients cardiac T2* and liver T2* were estimated. Result: (1) Four patients(7%) with β-TM were diagnosed diabetes mellitus, and 14(24%) had impaired fasting glucose. (2) The incidence of abnormal glucose metabolism was significantly different according to levels of SF and degrees of the cardiac iron overload(χ(2)=9.737, P<0.05; χ(2)=17.027, P<0.05). It rose while the level of SF increased and the degree of cardiac iron overload aggravated. (3) The incidence of abnormal glucose level was not significantly different in cases with different degree of liver iron overload.The severe group of liver iron overload had significantly higher levels of INS, HOMA-βFI, HOMA-ISI, HOMA-βFI than the non-severe group (Z=-2.434, -2.515, F=8.658, all P<0.05), while no differences were found in the level of FBG, HOMA-βFI between two groups. (4) The result of logistic regression analysis indicated that the cardiac T2* was a significant predictor for the incidence of abnormal glucose metabolism in TM patients (P=0.035, OR=1.182%, 95%CI=1.048 to 1.332). Conclusion: The high prevalence of abnormal glucose metabolism in β-TM patients was mainly closely related with the internal iron overload, especially in organs.The cardiac T2* was an independent risk factor for the incidence of abnormal glucose metabolism in TM patients.

Triphenyltin degradation and proteomic response by an engineered Escherichia coli expressing cytochrome P450 enzyme

Although triphenyltin (TPT) degradation pathway has been determined, information about the enzyme and protein networks involved was severely limited. To this end, a cytochrome P450 hydroxylase (CYP450) gene from Bacillus thuringiensis was cloned and expressed in Escherichia coli BL21 (DE3), namely E. coli pET32a-CYP450, whose dosage at 1gL^-1 could degrade 54.6% TPT at 1mgL^-1 within 6 d through attacking the carbon-tin bonds of TPT by CYP450. Sequence analysis verified that the CYP450 gene had a 1214bp open reading frame, encoding a protein with 404 amino acids. Proteomic analysis determined that 60 proteins were significantly differentially regulated expression in E. coli pET32a-CYP450 after TPT degradation. The up-regulated proteins enriched in a network related to transport, cell division, biosynthesis of amino acids and secondary metabolites, and microbial metabolism in diverse environments. The current findings demonstrated for the first time that P450 received electrons transferring from NADH could effectively cleave carbon-metal bonds.

Spectroscopic characterization of dissolved organic matter in coking wastewater during bio-treatment: full-scale plant study

This paper taking a full-scale coking wastewater (CWW) treatment plant as a case study aimed to characterize removal behaviors of dissolved organic matter (DOM) by UV spectra and fluorescence excitation-emission matrix-parallel factor analysis (PARAFAC), and investigate the correlations between spectroscopic indices and water quality parameters. Efficient removal rates of chemical oxygen demand (COD), dissolved organic carbon (DOC) and total nitrogen (TN) after the bio-treatment were 91.3%, 87.3% and 69.1%, respectively. UV270 was proven to be a stable UV absorption peak of CWW that could reflect the mixture of phenols, heterocyclics, polynuclear aromatic hydrocarbons and their derivatives. Molecular weight and aromaticity were increased, and also the content of polar functional groups was greatly reduced after bio-treatment. Three fluorescent components were identified by PARAFAC: C1 (tyrosine-like), C2 (tryptophan-like) and C3 (humic-like). The removal rate of protein-like was higher than that of humic-like and C1 was identified as biodegradable substance. Correlation analysis showed UV270 had an excellent correlation with COD (r=0.921, n=60, P<0.01) and DOC (r=0.959, n=60, P<0.01) and significant correlation (r=0.875, n=60, P<0.01) was also found between C2 and TN. Therefore, spectroscopic characterization could provide novel insights into removal behaviors of DOM and potential to monitor water quality real-time during CWW bio-treatment.

Effects of different algaecides on the photosynthetic capacity, cell integrity and microcystin-LR release of Microcystis aeruginosa

Bench scale tests were conducted to study the effects of four common algaecides, including copper sulfate, hydrogen peroxide, diuron and ethyl 2-methylacetoacetate (EMA) on the photosynthetic capacity, cell integrity and microcystin-LR (MC-LR) release of Microcystis aeruginosa. The release of potassium (K(+)) from cell membrane during algaecide exposure was also analyzed. The three typical photosynthetic parameters, including the effective quantum yield (Фe), photosynthetic efficiency (α) and maximal electron transport rate (rETRmax), were measured by a pulse amplitude modulated (PAM) fluorometry. Results showed that the photosynthetic capacity was all inhibited by the four algaecides, to different degrees, by limiting the energy capture in photosynthesis, and blocking the electron transfer chain in primary reaction. For example, at high diuron concentration (7.5 mg L(-1)), Фe, α and rETRmax decreased from 0.46 to 0.19 (p<0.01), from 0.20 to 0.01 (p<0.01) μmol electrons m(-2) s(-1)/μmol photons m(-2) s(-1), and from 160.7 to 0.1 (p<0.001) μmol m(-2) s(-1) compared with the control group after 96 h of exposure, respectively. Furthermore, the increase of algaecide dose could lead to the cell lysis, as well as release of intracellular MC-LR that enhanced the accumulation of extracellular MC-LR. The order of MC-LR release potential for the four algaecides was CuSO4>H2O2>diuron>EMA.

Immediate and long-term impacts of potassium permanganate on photosynthetic activity, survival and microcystin-LR release risk of Microcystis aeruginosa

The immediate and long-term impacts of potassium permanganate (KMnO(4)) as pre-oxidant on Microcystis aeruginosa and microcystin-LR (MC-LR) release risk were investigated. The cell density and the integrity of M. aeruginosa were determined by a flow cytometry, and typical photosynthetic parameters were measured by a pulse amplitude modulated fluorometer. The photosynthetic parameters were reduced to different degrees, accompanied with slight cytoclasis and complete degradation of extracellular MC-LR immediately after various dosages KMnO(4) oxidation (2-20 mg L(-1)). In a 6-d cultivation following 5 mg L(-1) KMnO(4) oxidation, the cell density decreased from 3.9×10(6) to 0.6×10(6) cells mL(-1), and then increased to 0.9×10(6) cells mL(-1), while the extracellular MC-LR increased from 0 to 51.2 μg L(-1). In the cultivation after 10 mg L(-1) KMnO(4) treatment, the intracellular MC-LR and cell activity significantly declined, while significant cytoclasis (cell density from 3.8×10(6) to 0 cells mL(-1)) and MC-LR release (increase from 0 to 15.2 μg L(-1)) were observed. The photosynthetic parameters were found to be useful tools to predict the recovery tendency of M. aeruginosa cells, and the MC-LR release risk should be considered during KMnO(4) pre-oxidation in water-treatment plants.

Immediate and long-term impacts of UV-C irradiation on photosynthetic capacity, survival and microcystin-LR release risk of Microcystis aeruginosa

In this study, the immediate and long-term impacts of shortwave ultraviolet (UV-C) irradiation on photosynthetic capacity, survival, and recovery of Microcystis aeruginosa were investigated. The risk of microcystin-LR (MC-LR) release during irradiation was also estimated. The cell density was determined by a flow cytometry, and typical chlorophyll fluorescence parameters, including the effective quantum yield, photosynthetic efficiency and maximal electron transport rate, were measured by a pulse amplitude modulated (PAM) fluorometer. Under various UV-C dosages (140-4200 mJ cm(-2)), photosynthetic capacities were reduced, to different degrees, accompanied by slight cytoclasis and complete degradation of extracellular MC-LR immediately after irradiation. In a 6-d cultivation following UV-C irradiation, cell density and extracellular MC-LR in the samples treated by 140 mJ cm(-2) UV-C irradiation increased from 4.0×10(6) cells mL(-1) and 8 μg L(-1) to 5.1×10(6) cells mL(-1) and 20 μg L(-1), respectively. Significant M. aeruginosa cytoclasis (cell density from 4.0×10(6) to 1.0×10(6) cells mL(-1)) and MC-LR release (2-25 μg L(-1)) occurred when the UV-C dosage reached 350 mJ cm(-2). Cell cytoclasis and MC-LR release were enhanced in the cultivated samples under higher UV-C dosages. Results revealed that photosynthetic parameters were useful tools to predict the recovery profiles of M. aeruginosa cells, and the MC-LR release risk should be considered after UV-C inactivation.

Inactivation and degradation of Microcystis aeruginosa by UV-C irradiation

In this study, the mechanisms and factors affecting the inactivation and degradation efficiency during UV-C irradiation of Microcystis aeruginosa, a harmful cyanobacteria strain, were investigated. Under different experimental conditions, the concentrations of three bioactivity materials, including protein, phycocyanin and chl-a, were measured, and fluorescence regional integration (FRI) was used to quantify the results of excitation emission matrix fluorescence spectroscopy. Furthermore, any alternation occurring in cell ultrastructure was determined using transmission electron microscopy. Results showed that UV-C could effectively damage the M.aeruginosa cells, most likely via a 3-step procedure, including impairment of photosynthesis system, decomposition of cytoplasmic inclusions, and cell cytoclasis. Comparison of FRI values and biochemical parameters in the presence of H(2)O(2) and HCO(3)(-) under the UV-C irradiation revealed the importance of photolysis and reactive oxygen species (ROS)-induced oxidation. UV-C/H(2)O(2) treatment was more efficient due to enhanced ROS generation, while adding HCO(3)(-) inhibited the ROS-induced oxidation, resulting in suppression on reaction. Humic acid and NO(3)(-), two common water solutes, somewhat inhibited the inactivation and degradation processes, due to the ROS scavenging and "inner filter" effect.

Retinoic acid-induced tissue transglutaminase and apoptosis in vascular smooth muscle cells

Retinoids exert antiproliferative and prodifferentiating effects in vascular smooth muscle cells (SMCs) and reduce neointimal mass in balloon-injured blood vessels. The mechanisms through which retinoids carry out these effects are unknown but likely involve retinoid receptor-mediated changes in gene expression. Here we report the cloning, chromosomal mapping, and biological activity of the retinoid-response gene rat tissue transglutaminase (tTG). Northern blotting studies showed that tTG is rapidly and dose-dependently induced in a protein synthesis-independent manner after stimulation with the natural retinoid all-trans retinoic acid (atRA). The induction of tTG was selective for atRA and its stereoisomers 9-cis and 13-cis RA, because little or no elevation in mRNA expression was observed with a panel of growth factors. Western blotting and immunofluorescence confocal microscopy showed an accumulation of cytosolic tTG protein after atRA stimulation. Radiolabeled cross-linking studies revealed a corresponding elevation in in vitro tTG activity. The increase in tTG activity was reduced in the presence of 2 distinct inhibitors of tTG (monodansylcadaverine and cystamine). atRA-induced tTG mRNA and protein expression were followed by a significant elevation in SMC apoptosis. Such retinoid-induced programmed cell death could be partially inhibited with each tTG inhibitor and was completely blocked when both inhibitors were used simultaneously. These results establish a role for atRA in the sequential stimulation of tTG and apoptosis in cultured SMCs. atRA-mediated apoptosis in SMCs seems to require the participation of active tTG, suggesting a potential mechanistic link between this retinoid-inducible gene and programmed cell death.

Nitric oxide synthase/nitric oxide pathway mediates intussusception pathogenesis in rats

OBJECTIVE

To study the role of nitric oxide synthase/nitric oxide pathway in the pathophysiological process of intussusception (IN).

METHODS

The IN model of rat was induced by lipopolysaccharide (LPS). The content of NOx in plasma and the NOS activity in colic smooth muscle tissues were measured. The content of cGMP was determined by radioimmunoassay.

RESULTS

LPS (10 mg/kg, i.p.) induced IN in up to 40% of the rats 6 hours after treatment with LPS. The incidence of IN was significantly increased by 58.3% (P < 0.05) and by 66.8% (P < 0.01) in L-arginine (L-Arg)-treated rats (2% in drinking water) and in sodium nitroprusside (NSP)-treated rats (1 mg/kg, i.p.), respectively, but it is significantly decreased by 66.8% (P < 0.01) after administration of M-omega-nitro-L-arginine methyl ester (L-NAME, 15 mg/kg, i.p.), an inhibitor of nitric oxide synthase (NOS) activity. Furthermore, LPS increased total NOS activity, NOx production and cGMP levels in plasma or in colic smooth muscle tissues. These parameters in LPS-IN rats were significantly elevated by 38.8%, 50.7%, and 48.7% respectively (P < 0.01) compared with LPS-non-IN rats.

CONCLUSION

NOS/NO pathway plays an important role in the process of IN, and inhibition of NO production may serve as a possible approach to prevent IN.

Laparoscopic-assisted mini laparatomy with colectomy

PURPOSE

Laparoscopic colectomy, as many claim, is technically feasible. However, none can definitely attest to its superiority over or even equivalence to traditional open laparotomy. The goal of this study is to assess results of laparoscopic colectomy via a new approach compared with traditional colectomy.

METHODS

The study involves 12 cases of laparoscopic mini laparotomy with colectomy and another 12 cases of traditional colectomy. Laparoscopic mini laparotomy is performed with the same equipment used in laparoscopic cholecystectomy. Through a small 5-cm to 6-cm incision, the surgeon's left hand inserts into the peritoneal cavity and participates in the laparoscopic mobilization of the bowel along with other laparoscopic instruments. Mesenteric division and bowel anastomosis are performed through the same incision extracorporeally.

RESULTS

The preliminary result of the study shows that, compared with traditional surgery, laparoscopic mini laparotomy with colectomy offers reduction in the frequency of usage of intramuscular analgesics, better cosmetic results, earlier food intake, and shorter hospital stay. The only disadvantage of laparoscopic mini laparotomy with colectomy is that it takes longer operative time, which may decrease with more experience.

CONCLUSION

Laparoscopic mini laparotomy with colectomy is an alternative method of laparoscopic colectomy. It seems to offer a similar morbidity and better results compared with colectomy in open laparotomy.

Concomitant renal cell carcinoma and metastatic epithelioid angiosarcoma with microangiopathy

Epithelioid angiosarcoma is an extremely rare clinical entity. Recognized only in recent years, epithelioid angiosarcoma mimicks epithelial tumors, both morphologically and immunohistochemically. It is very aggressive, assuming a rapid, metastatic and fatal course. This is a report of a case with an unequivocal diagnosis of epithelioid angiosarcoma and concomitant renal cell carcinoma. Reports of cancer with double origins of this combination, in patients without inherited von Hippel-Lindau disease, are extremely rare in the English literature. A review of the literature encompassing all cases of epithelioid angiosarcoma since 1983 is included.

A new dissecting technique of the gallbladder in laparoscopic cholecystectomy

Laparoscopic cholecystectomy is still a challenge to most general surgeons because of the complexity and length of the procedure. We have developed a timesaving technique of dissecting the gallbladder by using a dissection forceps. This new method reduces the operative time by half.