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.

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.