Instant water toxicity detection based on magnetically-constructed electrochemically active biofilm.

Water toxicity determination with electrochemically active bacteria (EAB) is promising in the early warning of water pollution. However, limited by tedious biofilm formation, natural EAB biofilms are uncapable of the instant detection of water toxicity, resulting in the failure for the emergency monitoring of water pollution. To solve this problem, a novel method for the rapid construction of EAB biofilms using magnetic adsorption was established, and the performance of instant water toxicity detection with magnetically-constructed EAB biofilm was investigated. The results demonstrate that EAB biofilms were magnetically constructed in less than 30 min, and magnetically-constructed EAB biofilm generated stable currents even under continuous flow conditions. Magnetically-constructed EAB biofilms realized instant water toxicity detection, and the sensitivity increased with the decrease of magnetic field intensity. Low magnetic field intensity resulted in a loose biofilm structure, which is conducive to toxic pollutant penetration. The detection limit for Cu2+, phenol, and Cd2+ achieved 0.07 mg/L with optimal magnetic field intensity, and the detection time was less than 30 min. This study broadens the application of water toxicity determination with EAB, and establishes a foundation for the instant and continuous detection of water toxicity with EAB.

Mechanism and applications of bidirectional extracellular electron transfer of Shewanella.

Electrochemically active microorganisms (EAMs) play an important role in the fields of environment and energy. Shewanella is the most common EAM. Research into Shewanella contributes to a deeper comprehension of EAMs and expands practical applications. In this review, the outward and inward extracellular electron transfer (EET) mechanisms of Shewanella are summarized and the roles of riboflavin in outward and inward EET are compared. Then, four methods for the enhancement of EET performance are discussed, focusing on riboflavin, intracellular reducing force, biofilm formation and substrate spectrum, respectively. Finally, the applications of Shewanella in the environment are classified, and the restrictions are discussed. Potential solutions and promising prospects for Shewanella are also provided.

Meta-analysis of microbial source tracking for the identification of fecal contamination in aquatic environments based on data-mining.

Microbial source tracking (MST) technology represents an innovative approach employed to trace fecal contamination in environmental water systems. The performance of primers may be affected by amplification techniques, target primer categories, and regional differences. To investigate the influence of these factors on primer recognition performance, a meta-analysis was conducted on the application of MST in water environments using three databases: Web of Science, Scopus, and PubMed (n = 2291). After data screening, 46 studies were included in the final analysis. The investigation encompassed Polymerase Chain Reaction (PCR)/quantitative PCR (qPCR) methodologies, dye-based (SYBR)/probe-based (TaqMan) techniques, and geographical differences of a human host-specific (HF183) primer and other 21 additional primers. The results indicated that the primers analyzed were capable of differentiating host specificity to a certain degree. Nonetheless, by comparing sensitivity and specificity outcomes, it was observed that virus-based primers exhibited superior specificity and recognition capacity, as well as a stronger correlation with human pathogenicity in water environments compared to bacteria-based primers. This finding highlights an important direction for future advancements. Moreover, within the same category, qPCR did not demonstrate significant benefits over conventional PCR amplification methods. In comparing dye-based and probe-based techniques, it was revealed that the probe-based method's advantage lay primarily in specificity, which may be associated with the increased propensity of dye-based methods to produce false positives. Furthermore, the heterogeneity of the HF183 primer was not detected in China, Canada, and Singapore respectively, indicating a low likelihood of regional differences. The variation among the 21 other primers may be attributable to regional differences, sample sources, detection techniques, or alternative factors. Finally, we identified that economic factors, climatic conditions, and geographical distribution significantly influence primer performance.

Arsenic induced autophagy-dependent apoptosis in hippocampal neurons via AMPK/mTOR signaling pathway.

Arsenic contamination of groundwater remains a serious public health problem worldwide. Arsenic-induced neurotoxicity receives increasing attention, however, the mechanism remains unclear. Hippocampal neuronal death is regarded as the main event of arsenic-induced cognitive dysfunction. Mitochondria lesion is closely related to cell death, however, the effects of arsenic on PGAM5-regulated mitochondrial dynamics has not been documented. Crosstalk between autophagy and apoptosis is complicated and autophagy has a dual role in the apoptosis pathways in neuronal cells. In this study, arsenic exposure resulted in mitochondrial PGAM5 activation and subsequent activation of apoptosis and AMPK-mTOR dependent autophagy. Intervention by autophagy activator Rapamycin or inhibitor 3-MA, both targeting at mTOR, accordingly induced activation or inhibition of apoptosis. Intervention by MK-3903 or dorsomorphin, activator or inhibitor of AMPK, received similar results. Our findings suggested that arsenic-induced PGAM5 activation played a role in AMPK-mTOR dependent autophagy and arsenic induced autophagy-dependent apoptosis in hippocampal neurons via AMPK/mTOR signaling pathway.

The role of ROS/p38 MAPK/NLRP3 inflammasome cascade in arsenic-induced depression-/anxiety-like behaviors of mice.

Arsenic pollution in groundwater remains a serious public health concern around the world. Recent years, arsenic-related neurological and psychiatric disorders have been reported increasingly. However, the exact mechanisms of it remains elusive. In this study, arsenic exposure through drinking water resulted in depression-/anxiety-like behaviors in mice accompanied by oxidative stress and NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome activation in prefrontal cortex (PFC) and hippocampus, two main affected areas found in neurobehavioral disorders. Intervention by NAC, a ROS scavenger, diminished the social behavior impairments in mice as well as ROS generation and NLRP3 inflammasome activation. Further study revealed that it was p38 MAPK signaling pathway that mediated ROS-induced NLRP3 inflammasome activation. Overall, our findings suggested that ROS/p38 MAPK/NLRP3 inflammasome cascade was involved in arsenic-induced depression-/anxiety-disorders. Furthermore, NAC might be a potential therapeutic agent for arsenic-induced depression-/anxiety-disorders by inhibiting both ROS generation and ROS-induced NLRP3 inflammasome activation.

Precision Therapy of Recurrent Breast Cancer through Targeting Different Malignant Tumor Cells with a HER2/CD44-Targeted Hydrogel Nanobot.

Heterogeneity and drug resistance of tumor cells are the leading causes of incurability and poor survival for patients with recurrent breast cancer. In order to accurately deliver the biological anticancer drugs to different subtypes of malignant tumor cells for omnidirectional targeted treatment of recurrent breast cancer, a distinct design is demonstrated by embedding liposome-based nanocomplexes containing pro-apoptotic peptide and survivin siRNA drugs (LPR) into Herceptin/hyaluronic acid cross-linked nanohydrogels (Herceptin-HA) to fabricate a HER2/CD44-targeted hydrogel nanobot (named as ALPR). ALPR delivered cargoes to the cells overexpressing CD44 and HER2, followed by Herceptin-HA biodegradation, subsequently, the exposed lipid component containing DOPE fused with the endosomal membrane and released peptide and siRNA into the cytoplasm. These experiments indicated that ALPR can specifically deliver Herceptin, peptide, and siRNA drugs to HER2-positive SKBR-3, triple-negative MDA-MB-231, and HER2-negative drug-resistant MCF-7 human breast cancer cells. ALPR completely inhibited the growth of heterogeneous breast tumors via multichannel synergistic effects: disrupting mitochondria, downregulating the survivin gene, and blocking HER2 receptors on the surface of HER2-positive cells. The present design overcomes the chemical drug resistance and opens a feasible route for the combinative treatment of recurrent breast cancer, even other solid tumors, utilizing different kinds of biological drugs.

On-site determination of water toxicity based on freeze-dried electrochemically active bacteria.

Our previous studies have reported water toxicity determination with a fresh electrochemically active bacteria (EAB) suspension as the sensing element, which exhibits high sensitivity and has great prospects in providing early warning about water pollution. However, because the preparation of fresh EAB suspensions is time-consuming, these studies are not suitable for the on-site determination of water toxicity. To solve this problem, this study investigated the rapid preparation of an EAB suspension by the rehydration of freeze-dried EABs and established a novel method for the on-site determination of water toxicity based on the freeze-dried EAB model strain Shewanella oneidensis MR-1. The results demonstrate that the optimal cryoprotectant for S. oneidensis MR-1 freeze drying is 7.5 % (w/v) skimmed milk powder. Compared with fresh S. oneidensis MR-1, freeze-dried S. oneidensis MR-1 exhibits similar extracellular electron transfer (EET) performance (74.7 % ± 0.3 %) and slightly lower sensitivity for water toxicity determination (65.8 % ± 2.2 %) with the optimal cryoprotectant. On-site determination of water toxicity was realized by using freeze-dried S. oneidensis MR-1, and the detection limits of five common toxic pollutants (Cd2+, Pb2+, Cu2+, phenol and dichlorophenol) reached 0.5 mg/L. Water toxicity determination is capable of resisting common interferences, e.g., glucose, lactate, nitrate and nitrite, and shows high accuracy in practical applications.

Computational Construction of a Single-Chain Bi-Paratopic Antibody Allosterically Inhibiting TCR-Staphylococcal Enterotoxin B Binding.

Staphylococcal enterotoxin B (SEB) simultaneously crosslinks MHC class II antigen and TCR, promoting proliferation of T cells and releasing a large number of toxic cytokines. In this report, we computationally examined the possibility of using a single-chain biparatopic bispecific antibody to target SEB and prevent TCR binding. The design was inspired by the observation that mixing two anti-SEB antibodies 14G8 and 6D3 can block SEB-TCR activation, and we used 14G8-6D3-SEB tertiary crystal structure as a template. Twelve simulation systems were constructed to systematically examine the effects of the designed bispecific scFV MB102a, including isolated SEB, MB102a with different linkers, MB102a-SEB complex, MB102a-SEB-TCRß complex, MB102a-SEB-TCR-MHC II complex, and MB102a-SEB-MHC II. Our all atom molecular dynamics simulations (total 18,900 ns) confirmed that the designed single-chain bispecific antibody may allosterically prevent SEB-TCRß chain binding and inhibit SEB-TCR-MHC II formation. Subsequent analysis indicated that the binding of scFV to SEB correlates with SEB-TCR binding site motion and weakens SEB-TCR interactions.

Quality of life of rural poor elderly in Anhui, China.

This study is to explore the quality of life (QoL) of the rural poor elderly in central China (Anhui province) and the influencing factors.A multi-stage random sampling method was used to extract 3352 effective samples of the rural elderly in Anhui, including 1206 poor and 2146 non-poor elderly subjects. Euro QoL 5-dimension questionnaire (EQ-5D) was used for the measurement of QoL. Descriptive statistics and χ test were used to compare and analyze the sociodemographic characteristics and QoL scores between poor and non-poor elderly. Multiple linear regression was used to assess the influencing factors of QoL.There were significant differences in gender, age, education levels, professions, chronic diseases, physical discomfort within 2 weeks, hospitalization within 1 year, economic sources, and migrant workers between the rural poor and non-poor elderly groups. The QoL of rural poor elderly scored significantly higher than the non-poor elderly, in all these five dimensions. The average EuroQol Visual Analogue Scale (EQ-VAS) of poor elderly was 65.689, lower than the non-poor elderly (71.039). After controlling the confounding factors, there was a significant statistical difference in the total utility score of EQ-5D between the poor and non-poor elderly groups.The QoL of poor elderly in central China is lower than non-poor elderly, with the worst dimension of pain/discomfort. The QoL of rural poor elderly in this area could be affected by many factors, to which more attention should be paid.

Correlation Between Depressive Symptoms And Quality Of Life, And Associated Factors For Depressive Symptoms Among Rural Elderly In Anhui, China.

PURPOSE: We aimed to assess the current status of depressive symptoms and quality of life (QoL) among rural elderly in central China (Anhui Province) and explore their correlation and associated factors for depressive symptoms. METHODS: A multi-stage random sampling method was used to obtain 3349 participants (aged ≥60): 1206 poor and 2143 non-poor. The 30-item Geriatric Depression Scale (GDS-30) and five-dimensional European quality of health scale (EQ-5D) were employed to evaluate depressive symptoms and QoL, respectively. RESULTS: The prevalence of depressive symptoms was 52.9%, and that in the poor group (62.3%) was significantly higher than the non-poor group (47.6%). The GDS-30 score was 12.40 ± 7.089, and the poor group scored significantly higher (14.045 ± 6.929) than the non-poor group (11.472 ± 7.011). The EQ-5D score was 0.713 ± 0.186, and the poor group (0.668 ± 0.192) scored significantly lower than the non-poor group (0.738 ± 0.178). There was a significant negative correlation between depressive symptoms and QoL (r = -0.400, P-value <0.05). The following factors were associated with depressive symptoms: poverty, low EQ-5D score, female gender, older age, illiteracy, unemployed, chronic diseases, and hospitalization in previous year. CONCLUSION: Rural elderly in central China have a high prevalence of depressive symptoms and low QoL. Poverty was associated with a higher prevalence of depressive symptoms and lower QoL.