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.

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.

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.

A Novel Model to Prevent Venous Thromboembolism in Patients with Lung Cancer.

Objective: To observe the effect of nurse-patient co-management mode on preventing venous thromboembolism (VTE) in lung cancer patients with carboplatin and gemcitabine chemotherapy after peripheral venipuncture central venous catheterization (PICC). Methods: 100 patients with lung cancer admitted to the 2nd Affiliated Hospital of Hainan Medical University from April 2020 to April 2022 were selected. All patients received a combination chemotherapy of carboplatin and gemcitabine and PICC catheterization. The patients were divided into an observation group and a control group by 1:1 simple random method, with 50 cases in each group. Patients in the control group were given routine nursing for lung cancer, and patients in the observation group were treated with nurse-patient co-management mode, and nursing intervention lasted for 2 months. General Comfort Questionnaire, self-management ability, quality of life, Self-care ability Scale, self-rating Anxiety Scale (SAS), and self-rating depression Scale were compared before and after intervention between the two groups. The recovery of immune ability indices (CD3+, CD3+CD4+, CD3+CD8+, CD3+CD4+/CD3+CD8+) in 2 groups were detected. Complications after PICC catheterization were recorded in the two groups. Results: After nursing, self-rating depression Scale and self-rating Anxiety Scale scores in both groups were significantly decreased, which were lower in the observation group than the control group (P < .001). After nursing, scores of self-concept, self-responsibility, self-care skills, and health knowledge level were significantly increased in both groups, which were higher in the observation group than control group (P < .001). After nursing, scores on the General Comfort Questionnaire, self-management scale, and quality of life were increased in both groups, which were higher in the observation group than control group (P < .0501). After nursing care, the immune competence indices of both patients increased significantly, and the immune indexes of CD3+, CD3+CD4+, and CD3+ CD4+/CD3+CD8+ in the observation group were significantly higher than those in the control group (P < .05). The total incidence of complications in the observation group was significantly lower than that in the control group (8.00% vs. 26.00%, P < .001), and the incidence of venous thromboembolism was significantly lower than that in the control group (2.00% vs. 14.00%, P < .001). Conclusion: The nurse-patient co-management model has shown to be effective in reducing the incidence of venous thromboembolism in patients who have undergone PICC catheterization while receiving carboplatin and gemcitabine chemotherapy. This model also helps patients improve their self-care and self-management abilities, alleviates adverse psychological effects, and contributes to the recovery of their immune system.

Mechanisms involved in the sequestration and resistance of cadmium for a plant-associated Pseudomonas strain.

Understanding Cd-resistant bacterial cadmium (Cd) resistance systems is crucial for improving microremediation in Cd-contaminated environments. However, these mechanisms are not fully understood in plant-associated bacteria. In the present study, we investigated the mechanisms underlying Cd sequestration and resistance in the strain AN-B15. These results showed that extracellular Cd sequestration by complexation in strain AN-B15 was primarily responsible for the removal of Cd from the solution. Transcriptome analyses have shown that the mechanisms of Cd resistance at the transcriptional level involve collaborative processes involving multiple metabolic pathways. The AN-B15 strain upregulated the expression of genes related to exopolymeric substance synthesis, metal transport, Fe-S cluster biogenesis, iron recruitment, reactive oxygen species oxidative stress defense, and DNA and protein repair to resist Cd-induced stress. Furthermore, inoculation with AN-B15 alleviated Cd-induced toxicity and reduced Cd uptake in the shoots of wheat seedlings, indicating its potential for remediation. Overall, the results improve our understanding of the mechanisms involved in Cd resistance in bacteria and thus have important implications for improving microremediation.

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 (FexOx) gradually became dominant, making MP-FexOx complexes. These FexOx 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 FexOx enhanced MP sorption dramatically, e.g., the kinetic constant Kf of ciprofloxacin raised from 0.206 (6.5 µm polystyrene) to 1.062 L g-1 (polystyrene-FexOx) 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.

Platelet-to-lymphocyte ratio associated with the clinicopathological features and prognostic value of breast cancer: A meta-analysis.

The association of platelet-to-lymphocyte ratio (PLR) with the clinicopathological features and prognosis in patients with breast cancer was evaluated. Related studies were searched from PubMed, Embase, Cochrane Library, and Web of Science up to July 1, 2021. Then, basic characteristic and prognostic data were extracted from the included studies. We synthesized and compared primary outcomes such as overall survival. Subgroups analyses in pathology, geographical area, follow-up time, and sample size were conducted. The pooled hazard ratio (HR), odds ratio (OR), and 95% confidence interval (CI) served as measures to assess the relationship of PLR with prognosis and clinicopathological features of breast cancer patients. After literature retrieval and selection, 20 studies with 7484 patients were included in this meta-analysis. High PLR was significantly related to poor overall survival (HR = 1.88; 95% CI 1.61, 2.19; P < 0.001) in breast cancer patients. Also, high PLR was associated with lymph node metastasis (LNM) (OR = 1.82; 95% CI 1.32, 2.52; P < 0.001), advanced tumor-node-metastasis (TNM) stage (OR = 1.89; 95% CI 1.25, 2.87; P = 0.003), and distant metastasis (OR = 1.76; 95% CI 1.14, 2.72; P = 0.01) in breast cancer. The stability and reliability of results in this meta-analysis were confirmed by sensitivity analysis. Elevated PLR is related to a poor prognosis and a higher risk of LNM, advanced TNM stage, and distant metastasis in breast cancer patients. Therefore, PLR can be identified as a biomarker with potential prognostic value in breast cancer.

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.

Clinical and Microbiological Characteristics of Bacteremic Pneumonia Caused by Klebsiella pneumoniae.

Klebsiella pneumoniae is a common pathogen of nosocomial pneumonia worldwide and community-acquired pneumonia (CAP) in Asia. Previous studies have shown that K. pneumoniae bacteremic CAP is associated with high mortality. We aimed to revisit K. pneumoniae bacteremic pneumonia in the current era and determine the risk factors associated with 28-day mortality. Between January 2014 and August 2020, adult patients with K. pneumoniae bacteremic pneumonia in a medical center in Taiwan were identified. Clinical and microbiological characteristics were compared between CAP and nosocomial pneumonia. Risk factors for 28-day mortality were analyzed using multivariate logistic regression. Among 150 patients with K. pneumoniae bacteremic pneumonia, 52 had CAP and 98 had nosocomial pneumonia. The 28-day mortality was 52% for all patients, 36.5% for CAP, and 60.2% for nosocomial pneumonia. Hypervirulent K. pneumoniae was more prevalent in CAP (61.5%) than in nosocomial pneumonia (16.3%). Carbapenem-resistant K. pneumoniae was more prevalent in nosocomial pneumonia (58.2%) than in CAP (5.8%). Nosocomial pneumonia, a higher Severe Organ Failure Assessment score, and not receiving appropriate definitive therapy were independent risk factors for 28-day mortality. In conclusion, revisiting K. pneumoniae bacteremic pneumonia in the current era showed a high mortality rate. Host factors, disease severity, and timely effective therapy affect the treatment outcomes of these patients.

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 (Kf 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.

Mechanisms controlling the transformation of and resistance to mercury(II) for a plant-associated Pseudomonas sp. strain, AN-B15.

Bioremediation using mercury (Hg)-volatilizing and immobilizing bacteria is an eco-friendly and cost-effective strategy for Hg-polluted farmland. However, the mechanisms controlling the transformation of and resistance to Hg(II) by these bacteria remain unknown. In this study, a plant-associated Pseudomonas sp. strain, AN-B15 was isolated and determined to effectively remove Hg(II) under both nutrient-poor and nutrient-rich conditions via volatilization by transforming Hg(II) to Hg(0) and immobilization by transforming Hg(II) to mercury sulfide and Hg-sulfhydryl. Genome and transcriptome analyses revealed that the molecular mechanisms involved in Hg(II) resistance in AN-B15 were a collaborative process involving multiple metabolic systems at the transcriptional level. Under Hg(II) stress, AN-B15 upregulated genes involved in the mer operon and producing the reducing power to rapidly volatilize Hg(II), thereby decreasing its toxicity. Hydroponic culture experiments also revealed that inoculation with strain AN-B15 alleviated Hg-induced toxicity and reduced the uptake of Hg(II) in the roots of wheat seedlings, as explained by the volatilization and immobilization of Hg(II) and plant growth-promoting traits of AN-B15. Overall, the results from the in vitro assays provided vital information that are essential for understanding the mechanism of Hg(II) resistance in plant-associated bacteria, which can also be applied for the bioremediation of Hg-contamination in future.

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.

Joint pollution and source apportionment of PM2.5 among three different urban environments in Sichuan Basin, China.

The PM2.5 were sampled in three different urban environments: (city of) Chengdu, Leshan, and Dazhou, which are located in Sichuan Basin. 8 types of water-soluble ion and 25 types of metal element were measured in each PM2.5 sample across the seasons of 2017. The study results suggest that the joint PM2.5 pollution among the three cities mainly occurred in autumn and winter, and the air quality of Chengdu and Leshan was largely affected by Dazhou. Overall, the mass concentrations of PM2.5 of these three cities exhibited no statistically significant differences. However, Leshan had the highest level of ionic pollution, and the dominant form of inorganic compound in ambient PM2.5 was NH4NO3, and a competitive relationship between form of NH4NO3 and (NH4)2SO4 (NH4HSO4) was found as well. High homology between SO42- and NO3- has been observed in all the three cities, and the ratio between [SO42-] and [NO3-] indicated that the stationary source contributed the most to ambient PM2.5 in Dazhou. The mass concentrations of the total metal elements from the three cities exhibited similar levels, nevertheless, Dazhou had the highest mass fraction of total metal elements in PM2.5. The enrichment factor of each element indicated that the natural source was highly contributory to the crustal elements in PM2.5 of all the three cities, whereas Cr, Cu, Se, Mo, Cd, Tl and Bi were primarily originated from anthropogenic source. In addition, the source apportionment of PM2.5 suggest that Dazhou had the different factors and factor-contributions comparing with Chengdu and Leshan.