Thermal-Sensitive Supramolecular Coordination Complex Formed by Orthogonal Metal Coordination and Host-Guest Interactions for an Electrical Thermometer.

Supramolecular coordination complexes (SCCs) are popular for their structural diversity and functional adaptability, which make them suitable for a wide range of applications. Photophysical and mechanical performance of SCCs are the most attractive characteristics, yet their ionically conductive behavior and potential in electrical sensing have been rarely investigated. This study reports a well-designed SCC that integrates orthogonal metal coordination and host-guest interactions to achieve sensitive electrical thermal sensing. Owing to the thermodynamic nature of the host-guest interaction, the SCC encounters thermally induced disassembly, leading to significantly enhanced ion mobility and thus allowing for the precise detection of minor temperature variation. The SCC-based thermometer is then fabricated with the assistance of 3D printing and demonstrates good accuracy and reliability in monitoring human skin temperature and real-time temperature changes of mouse during the whole anesthesia and recovery process. Our findings provide an innovative strategy for developing electrical thermometers and expand the current application scope of SCCs in electrical sensing.

Self-powered biosensing sutures for real-time wound monitoring.

Effective wound management has the potential to reduce both the duration and cost of wound healing. However, traditional methods often rely on direct observation or complex and expensive biological testing to monitor and evaluate the invasive damage caused by wound healing, which can be time-consuming. Biosensors offer the advantage of precise and real-time monitoring, but existing devices are not suitable for integration with sensitive wound tissue due to their external dimensions. Here, we have designed a self-powered biosensing suture (SPBS) based on biofuel cells to accurately monitor glucose concentration at the wound site and promote wound healing. The anode of the SPBS consists of carbon nanotubes-modified carbon fibers, tetrathiafulvalene (TTF), and glucose oxidase (GOx), while the cathode is composed of Ag2O and carbon nanotubes modified nanotubes modified carbon fibers. It was observed that SPBS exhibited excellent physical and chemical stability in vitro. Regardless of different bending degrees or pH values, the maximum power density of SPBS remained above 92%, which is conducive to long-term dynamic evaluation. Furthermore, the voltage generated by SPBS reflects blood glucose concentration, and measurements at wound sites are consistent with those obtained using a commercially available blood glucose meter. SPBS achieves the healing effect of traditional medical sutures after complete healing within 14 days. It offers valuable insights for intelligent devices dedicated to real-time wound monitoring.

Comparative Analysis of Main Agronomic Traits of Different Pleurotus giganteus Germplasm Resources.

Agronomic traits are key components in variety protection, cultivar development, and the formulation of DUS (distinct, uniform, and stable) test guidelines. P. giganteus is an increasingly popular and commercially promising edible macrofungi. In this study, both mycelial performance and fruiting body characters of 15 Pleurotus giganteus strains were investigated. The temperature gradient culture test indicated that, although most of the strains achieved optimal mycelial growth between 24 and 28 °C, a statistical difference in mycelial growth rates and temperature adaptability among strains were found, supporting that this trait has the potential to be adopted as an indicator in distinguishing strains. In the fruiting performance tests, the coefficient of variation (CV) of tested traits ranged from 5.30% (pileus diameter) to 18.70% (individual mushroom weight). The mushroom yields ranged from 103.37 g/bag (strain No. 15) to 275.76 g/bag (strain No. 9). The large divergence observed in individual mushroom weight tested strains, ranging from 40.88 g to 78.39 g (with median between 37.69 and 79.395 g), make it highly selective and a potential indicator in variety development. Strain No. 9 had the advantages of forming larger, heavier fruiting bodies and a more obvious funnel shape, which also exhibited the highest biological efficiency (15.61%). The results suggested some morphological traits showed high variety difference, such as pileus diameter (55.75 mm to 66.48 mm), stipe length (92.59 mm to 177.51 mm), stipe diameter (16.14 mm to 23.52 mm), and pileus thickness (13.38 mm to 19.75 mm). In the cluster analysis, the tested strains were grouped into four clusters based on agronomic traits: cluster Ⅰ comprised six strains (No. 6, No. 11, No. 8, No. 1, No. 14, and No. 9) with high mushroom yield; cluster Ⅱ included four strains (No. 3, No. 10, No. 7, and No. 4) with large pileus diameter and short stipe; cluster ⅡI consisted of four strains (No. 5, No. 12, No. 13, and No. 15) with relatively lower yields; and cluster Ⅳ included only strain No. 2 which was low in yield, individual mushroom weight, and biological efficiency, accompanied by smaller pileus size and shorter stipe. The results of the correlation analysis indicated three traits, including individual mushroom weight, stipe length, and pileus weight, were positively associated with high yield. This study suggested P. giganteus germplasm resources are of high abundance and their agronomic diversity is useful in distinguishing and developing different varieties. The findings of this work provide knowledge on the agronomic traits and cultivation performance of various P. giganteus strains, laying a foundation for the development of its DUS test guidelines and variety protection, as well as providing reference for the breeding and phenotype selection of high-quality cultivars.

Potential of nonporous adaptive crystals for hydrocarbon separation.

Hydrocarbon separation is an important process in the field of petrochemical industry, which provides a variety of raw materials for industrial production and a strong support for the development of national economy. However, traditional separation processes involve huge energy consumption. Adsorptive separation based on nonporous adaptive crystal (NAC) materials is considered as an attractive green alternative to traditional energy-intensive separation technologies due to its advantages of low energy consumption, high chemical and thermal stability, excellent selective adsorption and separation performance, and outstanding recyclability. Considering the exceptional potential of NAC materials for hydrocarbon separation, this review comprehensively summarizes recent advances in various supramolecular host-based NACs. Moreover, the current challenges and future directions are illustrated in detail. It is expected that this review will provide useful and timely references for researchers in this area. Based on a large number of state-of-the-art studies, the review will definitely advance the development of NAC materials for hydrocarbon separation and stimulate more interesting studies in related fields.

Comparative analysis of proteomes and transcriptomes revealed the molecular mechanism of development and nutrition of Pleurotus giganteus at different fruiting body development stages.

Pleurotus giganteus is a commercially cultivated high-temperature mushroom. Investigating the molecular mechanism of fruiting body development will help us to better understand the regulation of substrates and energy in this process. However, little information has been reported on the development and nutrients of the P. giganteus fruiting body. In the present study, P. giganteus is cultivated in a climate chamber, and comparative transcriptome, proteome, and nutritional analysis of P. giganteus fruiting bodies were performed. Our results revealed that Cytochrome P450 monooxygenases and hydrophobin proteins play important roles during the differentiation in the elongation stage. Later, carbon metabolism dominate the fruiting body metabolism and genes related to the carbohydrate metabolic process, glycolytic process, and gluconeogenesis were up-regulated in the mature fruiting bodies. The up-regulation of carbohydrate substrates utilization CAZymes genes and inconsistent protein expression in pileus indicated a reverse transportation of mRNA from the fruiting body to vegetative mycelia. In addition, protein concentration in the pileus is higher than that in the stem, while the stem is the major nitrogen metabolic and amino acid synthetic location. The integrated transcriptomic, proteomic, and nutritional analysis indicated a two-way transportation of substrates and mRNAs in P. giganteus. Stem synthesizes amino acids and transported them to pileus with reducing sugars, while pileus induces the expression of substrate degradation mRNA according to the needs of growth and development and transports them in the other direction.

The mediating role of menstrual irregularity on obesity and sexual function in Chinese women with pelvic floor disorders: a cross-sectional study.

BACKGROUND: Sexual problems are common among women with pelvic floor disorders (PFD). Few studies have explored the relationship between obesity and sexual function in women with PFD. This study aimed to prove that obesity was a risk factor for worse sexual function in women with PFD, and to investigate the mediating role of menstrual irregularity. METHODS: This was a cross-sectional study involving 783 women with PFD from Shandong Province, China between June 2020 and February 2021. Female sexual function was assessed using the Pelvic Organ Prolapse/UI Sexual Questionnaire-12 (PISQ-12). Obesity was defined as BMI ≥ 28.0. Menstrual irregularity was defined as menstrual cycles ≥ 35 or menstrual cycles < 25 days. Logistic regression and multiple linear regression were employed to explore the association among obesity, menstrual irregularity and sexual function. RESULTS: Obesity was associated with worse PISQ-12 scores compared with normal- weight women (mean score 28.14 ± 7.03 versus 32.75 ± 5.66, p < 0.001). After adjusting for controlling variables, women with obesity (ß= -3.74, p < 0.001) and menstrual irregularity (ß= -3.41, p < 0.001) had a worse sexual function. Menstrual irregularity had a mediation effect on the association between obesity and sexual function. CONCLUSIONS: This study provided evidence that obesity was associated with worse sexual function in women with PFDs, and the effect of obesity on sexual function was partially mediated by menstrual irregularity. Weight control may have potential benefits for improving sexual function and preventing female sexual dysfunction. It's also important to pay attention to the menstrual cycle.

Infection of porcine enteroids and 2D differentiated intestinal epithelial cells with rotavirus A to study cell tropism and polarized immune response.

Intestinal epithelial cell interactions with enteric pathogens have been incompletely elucidated owing to the lack of model systems that recapitulate the cellular diversity, architecture and functionality of the intestine. To analyze rotavirus (RV) infection and the subsequent innate immune response, we established cultures of differentiated porcine intestinal epithelial cells in three different variations: basolateral-out enteroids, apical-out enteroids and two-dimensional (2D) filter-grown intestinal epithelial cells. Application of specific antibodies for fluorescent staining indicated that enteroids and enteroid-derived cell cultures contain multiple intestinal epithelial cell types. Infection studies indicated that both apical-out enteroids and 2D intestinal epithelial cells are susceptible to porcine RV infection. However, 2D intestinal epithelial cells are more useful for a detailed characterization and comparison of apical and basolateral infection than apical-out enteroids. Virus-induced apoptosis was observed in apical-out enteroids at 24 h post infection but not at earlier time points after infection. RV infected not only enterocytes but also goblet cells and Paneth cells in apical-out enteroids and 2D intestinal epithelial cells. Interestingly, despite the lack of significant differences in the efficiency of infection after apical and basolateral infection of 2D intestinal epithelial cells, stronger innate immune and inflammatory responses were observed after basolateral infection as compared to infection via the apical route. Therefore, apical-out enteroids and 2D intestinal epithelial cells provide useful primary cell culture models that can be extended to analyze invasion and replication strategies of agents implicated in enteric diseases or to study immune and inflammatory responses of the host induced by enteric pathogens.

Recent Progress of Supramolecular Chemotherapy Based on Host-Guest Interactions.

Chemotherapy is widely recognized as an effective approach for treating cancer due to its ability to eliminate cancer cells using chemotherapeutic drugs. However, traditional chemotherapy suffers from various drawbacks, including limited solubility and stability of drugs, severe side effects, low bioavailability, drug resistance, and challenges in tracking treatment efficacy. These limitations greatly hinder its widespread clinical application. In contrast, supramolecular chemotherapy, which relies on host-guest interactions, presents a promising alternative by offering highly efficient and minimally toxic anticancer drug delivery. In this review, an overview of recent advancements in supramolecular chemotherapy based on host-guest interactions is provided. The significant role it plays in guiding cancer therapy is emphasized. Drawing on a wealth of cutting-edge research, herein, a timely and valuable resource for individuals interested in the field of supramolecular chemotherapy or cancer therapy, is presented. Furthermore, this review contributes to the progression of the field of supramolecular chemotherapy toward clinical application.

Infection Studies with Airway Organoids from Carollia perspicillata Indicate That the Respiratory Epithelium Is Not a Barrier for Interspecies Transmission of Influenza Viruses.

Bats are a natural reservoir for many viruses and are considered to play an important role in the interspecies transmission of viruses. To analyze the susceptibility of bat airway cells to infection by viruses of other mammalian species, we developed an airway organoid culture model derived from airways of Carollia perspicillata. Application of specific antibodies for fluorescent staining indicated that the cell composition of organoids resembled those of bat trachea and lungs as determined by immunohistochemistry. Infection studies indicated that Carollia perspicillata bat airway organoids (AOs) from the trachea or the lung are highly susceptible to infection by two different porcine influenza A viruses. The bat AOs were also used to develop an air-liquid interface (ALI) culture system of filter-grown epithelial cells. Infection of these cells showed the same characteristics, including lower virulence and enhanced replication and release of the H1N1/2006 virus compared to infection with H3N2/2007. These observations agreed with the results obtained by infection of porcine ALI cultures with these two virus strains. Interestingly, lectin staining indicated that bat airway cells only contain a small amount of alpha 2,6-linked sialic acid, the preferred receptor determinant for mammalian influenza A viruses. In contrast, large amounts of alpha 2,3-linked sialic acid, the preferred receptor determinant for avian influenza viruses, are present in bat airway epithelial cells. Therefore, bat airway cells may be susceptible not only to mammalian but also to avian influenza viruses. Our culture models, which can be extended to other parts of the airways and to other species, provide a promising tool to analyze virus infectivity and the transmission of viruses both from bats to other species and from other species to bats. IMPORTANCE We developed an organoid culture system derived from the airways of the bat species Carollia perspicillata. Using this cell system, we showed that the airway epithelium of these bats is highly susceptible to infection by influenza viruses of other mammalian species and thus is not a barrier for interspecies transmission. These organoids provide an almost unlimited supply of airway epithelial cells that can be used to generate well-differentiated epithelial cells and perform infection studies. The establishment of the organoid model required only three animals, and can be extended to other epithelia (nose, intestine) as well as to other species (bat and other animal species). Therefore, organoids promise to be a valuable tool for future zoonosis research on the interspecies transmission of viruses (e.g., bat → intermediate host → human).

Development of KLA-RGD integrated lipopeptide with the effect of penetrating membrane which target the αvß3 receptor and the application of combined antitumor.

Herein, an amphiphilic cationic anticancer lipopeptide P17 with α-helical structure was synthesized based on the integration of KLA and RGD peptide which could bind with the receptor of integrin αvß3. P17 could self assemble into stable spherical aggregates in aqueous solution, and which could encapsulate the anticancer drugs (Such as Dox) to form P17 @ Anticancer drug nanomedicine (P17 @ Dox nanomedicine) which could play the combined therapy of P17 and anticancer drugs (Dox). The encapsulation efficiency of P17 aggregates to Dox was 80.4 ± 3.2 %, and the release behavior of P17 @ Dox nanomedicine in vitro had the characteristics of slow-release and pH responsiveness. The experiments in vitro showed that P17 lipopeptide had low cytotoxicity, high serum stability, low hemolysis and strong penetrating membrane ability. The release of Dox from P17 @ Dox in cells was time-dependment, and the P17 @ Dox nanomedicine had a good anticancer effect. The experiments in vivo showed that P17 and P17 @ Dox nanomedicine both had low hemolysis, and P17 @ Dox nanomedicine could effectively inhibit tumor growth and significantly reduce the toxic and side effects of Dox. Molecular docking experiments showed that P17 could effectively interact with the receptor of integrin αvß3. In conclusion, P17 lipopeptide could be used as an excellent drug carrier and play the combined anticancer effect of P17 and anticancer drugs.

Pillararene-Based Supramolecular Polymers for Cancer Therapy.

Supramolecular polymers have attracted considerable interest due to their intriguing features and functions. The dynamic reversibility of noncovalent interactions endows supramolecular polymers with tunable physicochemical properties, self-healing, and externally stimulated responses. Among them, pillararene-based supramolecular polymers show great potential for biomedical applications due to their fascinating host-guest interactions and easy modification. Herein, we summarize the state of the art of pillararene-based supramolecular polymers for cancer therapy and illustrate its developmental trend and future perspective.

Supramolecular host-guest nanosystems for overcoming cancer drug resistance.

Cancer drug resistance has become one of the main challenges for the failure of chemotherapy, greatly limiting the selection and use of anticancer drugs and dashing the hopes of cancer patients. The emergence of supramolecular host-guest nanosystems has brought the field of supramolecular chemistry into the nanoworld, providing a potential solution to this challenge. Compared with conventional chemotherapeutic platforms, supramolecular host-guest nanosystems can reverse cancer drug resistance by increasing drug uptake, reducing drug efflux, activating drugs, and inhibiting DNA repair. Herein, we summarize the research progress of supramolecular host-guest nanosystems for overcoming cancer drug resistance and discuss the future research direction in this field. It is hoped that this review will provide more positive references for overcoming cancer drug resistance and promoting the development of supramolecular host-guest nanosystems.

Network Pharmacology and Experimental Validation to Reveal Effects and Mechanisms of Icariin Combined with Nobiletin against Chronic Obstructive Pulmonary Diseases.

Background: Chronic obstructive pulmonary disease (COPD) is a long-term respiratory disorder marked by restricted airflow and persistent respiratory symptoms. According to previous studies, icariin combined with nobiletin (I&N) significantly ameliorates COPD, but the therapeutic mechanisms remain unclear. Purpose: The aim of the study is to investigate the therapeutic mechanisms of I&N against COPD using network pharmacology and experimental validation. Methods: The targets of I&N and related genes of COPD were screened and their intersection was selected. Next, the protein-protein interaction (PPI) networks, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed. Further, a COPD rat model was established to validate the effect and mechanisms of I&N. Results: 445 potential targets I&N were obtained from SwissTargetPrediction, STITCH 5.0, and PharmMapper databases. 1831 related genes of COPD were obtained from GeneCards, DrugBank, and DisGeNet databases. 189 related genes were screened via matching COPD targets with I&N. 16 highest score targets among 189 targets were obtained according to PPI networks. GO and KEGG pathway enrichment analyses of 16 highest score targets suggested that these key genes of I&N were mostly enriched in the tumor necrosis factor (TNF) pathway, mitogen-activated protein kinase (MAPK) pathway, and phosphatidyl inositol 3-kinase (PI3K)-protein kinase B (AKT) pathway. Therefore, the treatments of I&N for COPD were connected with inflammation-related pathways. In in vivo experiments, the studies indicated that I&N improved the lung function and alleviated the damage of pulmonary histopathology. Moreover, I&N reduced levels of interleukin (IL)-6, IL-1ß, and TNF-α in lung tissues of COPD rats and inhibited the activation of the MAPK pathway and PI3K-Akt pathway. Conclusions: Icariin combined with nobiletin has therapeutic effects on COPD by inhibiting inflammation. The potential mechanisms of I&N may relate to the MAPK pathway and PI3K-Akt pathway.

Development of Drug Carriers with Biocompatibility Based On Human Serum Albumin and ß-Cyclodextrin Molecules and Study of Anticancer Activity.

Herein, a novel molecule S4, which could form a uniform S4 spherical aggregate in water, was synthesized, and the S4 aggregate was used to load Dox to prepare the S4@Dox nanomedicine. The loading efficiency was 80.0 ± 4.5%. The pH response and slow release of Dox were the typical characteristics of the S4@Dox nanomedicine. In vitro experiments showed that cancer cells could successfully phagocytose S4 aggregates and the S4@Dox nanomedicine. The toxicity of S4 aggregates to MCF-7, HepG2, and H22 cells was low, and the S4@Dox nanomedicine had better antitumor activity and specific targeting, especially to the MCF-7 cells. The antitumor activity in vivo and in the tissue section showed that the S4@Dox nanomedicine could significantly reduce Dox toxicity, effectively induce the apoptosis of cancer cells, and effectively inhibit tumor growth, which showed that the nanomedicine had better antitumor activity.

Simulation of a micron resolution capillary liquid scintillation detector for 14 MeV fusion neutrons.

Aiming to improve the spatial resolution of a neutron imaging system (NIS) for 14 MeV fusion neutrons, an ideal micron resolution capillary detector filled with a high optical index liquid scintillator was simulated. A threshold for each capillary pixel and a threshold for each cluster were applied to suppress the gamma-induced background. In addition, by using a pattern recognition algorithm and an optimized Hough transform, the accuracy of determining the neutron impinging positions and the dynamic range of this detector were enhanced. For an ideal capillary array detector, the spatial resolution is expected as one capillary size of 20µm. The dynamic range of ∼1000 is reachable while the accuracy of neutron impinging position determination keeps better than 85%. The ionization quenching, light sharing and energy resolution of the detector were applied to the simulated data to understand the capillary array detector.

Development of anticancer peptides with low hemolysis, high penetrating membrane activity, certain analgesic activity and the synergistic anticancer effect.

Herein, an amphiphilic cationic α-helical anticancer lipopeptide, P10 with low toxicity and high penetrating membrane activity was developed. This lipopeptide could self-assemble into stable spherical aggregates in aqueous solution and encapsulate Dox with a hydrophobic structure to form the P10@Dox nanomedicine. The Dox encapsulation efficiency was 81.3% ± 3.48% and its release from the P10@Dox nanomedicine had the characteristics of slow release and pH response. The in vitro experiments showed that the P10 lipopeptide had low toxicity, excellent membrane penetrating activity and high serum stability, the release of Dox from P10@Dox in cells was time and concentration dependent, and the P10@Dox nanomedicine played a good anti-cancer role. The animal experiments and tissue sections showed that the P10 lipopeptide and P10@Dox nanomedicine both had low hemolysis, and P10@Dox nanomedicine not only greatly reduced the toxicity and side effects of Dox, but also effectively inhibited the tumor growth. Additionally, it was surprising that P10 exhibited certain analgesic activity, which could reduce the accompanying cancer pain, while playing an effective role in cancer therapy. Thus, the results showed that the P10 lipopeptide can be used as an ideal drug carrier and it has great application potential in the field of clinical cancer therapy.

The mediating effect of the prolonged second stage of labor on delivery mode and urinary incontinence among postpartum women: evidence from Shandong, China.

INTRODUCTION AND HYPOTHESIS: This study was aimed at exploring the mediating role of the prolonged second stage of labor (PSSL) in the association between delivery mode and urinary incontinence (UI) among postpartum women in Shandong, China. METHODS: A cross-sectional study involving postnatal women from the Women's Pelvic Floor Functional Health Center in Shandong, China, was conducted. An electronic questionnaire was used to collect the data between June 2020 and February 2021. UI was assessed using the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form (ICIQ-UI SF). Logistic regression and multiple linear regression were employed to explore the association among delivery mode, PSSL, and UI, and the mediating role of PSSL. RESULTS: Among the total of 5,586 postpartum women included in this study, the prevalence of UI was 13.3%. Among the 742 patients with UI, the prevalence of stress urinary incontinence (78.3%) was greater than urge urinary incontinence (8.6%), mixed urinary incontinence (9.3%), and others (3.8%). After adjusting for controlling variables, delivery mode was found to be significantly associated with PSSL, whereby women with vaginal delivery were more likely to be in PSSL, and women with PSSL had a higher probability of suffering from UI. PSSL played a partial mediating effect in delivery mode and UI. CONCLUSIONS: This study provided evidence that the effect of delivery mode on UI was partially mediated by PSSL among postpartum women in Shandong, China. Strategies to prevent PSSL should be actively adopted to reduce the risk of UI in women.

IFIT5 Negatively Regulates the Type I IFN Pathway by Disrupting TBK1-IKKε-IRF3 Signalosome and Degrading IRF3 and IKKε.

IFN-induced protein with tetratricopeptide repeats (IFITs), known as canonical IFN-stimulated genes (ISGs), play critical roles in regulating immune responses against pathogens and maintaining homeostasis. How the IFIT5 regulates innate immune responses is rarely reported and remains enigmatic. In this study, we discover that human IFIT5 (hIFIT5) functions as a negative regulator of the type I IFN (IFN) pathway in HEK293T cell lines. Our data illustrated that hIFIT5 inhibited the promotor activities of IFN-ß induced by IRF3 and its upstream factors but not by IRF3-5D (activated form of IRF3), suggesting that IRF3 might be a target of hIFIT5. Further investigations revealed that hIFIT5 downregulated the phosphorylation of IRF3 and IKKε and blocked the IRF3 nuclear translocation. Moreover, hIFIT5 impaired the IRF3-TBK1-IKKε complex, accompanied by IRF3 and IKKε degradation. In conclusion, these findings indicate that hIFIT5 is a negative modulator in the type I IFN signaling pathway, opening additional avenues for preventing hyperactivation and maintaining immunity homeostasis.

[Mechanism of Algal Community Dynamics Driven by the Seasonal Water Bacterial Community in a Stratified Drinking Water Reservoir].

Phytoplankton and bacteria are crucial components of aquatic food webs, playing critical roles in the structure and function of freshwater ecosystems. However, there are few studies on how the algal and bacterial communities interact and respond to changing environmental conditions in the water reservoirs. Thus, the ecological interaction relationship between the temporal succession of the phytoplankton community and the bacterial community was investigated using 16S rDNA high-throughput sequencing and a co-occurrence network in the Lijiahe Reservoir. The results showed that Bacillariophyta and Chlorophyta were also dominant taxa in the phytoplankton community. In August, Cyanobacteria replaced Bacillariophyta as the second-most dominant taxa, with an average relative abundance of 30.13%. DNA sequencing showed that Proteobacteria, Actinobacteria, and Bacteroidetes dominated throughout the year. Proteobacteria reached a maximum relative abundance of 71.68% in July. Acidobacteria and Deinococcus-Thermus, which were rare taxa, reached maximum relative abundances of 10.20% and 5.56%, respectively. The co-occurrence network showed that the association between algae and bacteria was mainly positive, indicating that the interaction between them may be dominated by mutualism. As a keystone taxa, Methylotenera was significantly and positively related to Chlorella. Scenedesmus was also a keystone taxa and was significantly and negatively correlated with various bacteria, such as Methylobacter, Solitalea, and Rhodoferax. An RDA analysis showed that the succession of algal and bacterial communities was significantly regulated by water temperature, pH, and conductivity, and the environmental factors explained 93.1% and 90% of the variation in the algal community and bacterial community, respectively. The results will provide a scientific basis for exploring the micro-ecological driving mechanism of the interaction between algae and bacteria in deep drinking water reservoir ecosystems.

Combined effects of seasonality and stagnation on tap water quality: Changes in chemical parameters, metabolic activity and co-existence in bacterial community.

In drinking water distribution pipeline systems, the tap water quality is regulated by several biotic and abiotic factors, which can threaten the health of consumers. Stagnation is inevitable in the water distribution pipeline however, the combined effects of seasonal changes and stagnation on tap water quality are not well understood. Here, we investigated the seasonal variations in the chemical and biological quality of water after overnight stagnation for a period of one year. The results showed that the tap water quality deteriorated after overnight stagnation, with up to a 2.7-fold increase in the total iron concentrations. The total bacterial cell concentrations increased by 59-231% after overnight stagnation. The total cell and cell-bound adenosine triphosphate (ATP) of the stagnant water samples peaked in summer. In addition, Biolog analysis showed that the metabolic activities of microbes were higher in spring. The bacterial community based on Illumina Miseq DNA sequence analysis found that Proteobacteria dominated the drinking water bacterial community. The bacterial community structure varied significantly among different seasons, where the diversity and richness of the community were much higher in spring. Structural equation modeling (SEM) was constructed to determine the correlations between bacterial metabolic functions and the community structure. The redundancy analysis (RDA) indicated that the residual chlorine played a critical role in the construction of the bacterial community. Altogether, the overall findings from the present work provide novel insights into how the quality of tap water quality impacted by the seasonal changes and overnight stagnation.