Guided Design of Efficient Oxygen Evolution Catalysts Using Patent Analysis.

The facile and rapid design of efficient oxygen evolution reaction (OER) catalysts holds paramount significance for energy conversion devices, such as water electrolyzers and fuel cells. Despite substantial progress in catalyst synthesis and performance exploration, the design and selection processes remain inefficient. In this context, we integrate patent analysis with catalyst design, leveraging the scholarly research functionalities within patent analyses to aid in the design and synthesis of a NiFeRu-carbon catalyst as a high-performance OER catalyst. The results demonstrate that the NiFeRu-Carbon catalyst with low Ru loading (0.3 wt %) exhibits an overpotential of only 219 mV at 10 mA cm-2 under alkaline conditions, and after continuous operation for 200 h, the overpotential only attenuates by 15 mV. The incorporation of high-valence Ru dopants elevated the intrinsic activity of individual catalytic sites within NiFe-layered double hydroxides (LDHs). During the catalytic process, the partial dissolution of Ru might lead to the generation of numerous oxygen vacancies within NiFe- LDH, thereby enhancing the catalyst's activity and stability.

Oncogenic Roles of Laminin Subunit Gamma-2 in Intrahepatic Cholangiocarcinoma via Promoting EGFR Translation.

Intrahepatic cholangiocarcinoma (iCCA) is a highly lethal biliary epithelial cancer in the liver. Here, Laminin subunit gamma-2 (LAMC2) with important oncogenic roles in iCCA is discovered. In a total of 231 cholangiocarcinoma patients (82% of iCCA patients) across four independent cohorts, LAMC2 is significantly more abundant in iCCA tumor tissue compared to normal bile duct and non-tumor liver. Among 26.3% of iCCA patients, LAMC2 gene is amplified, contributing to its over-expression. Functionally, silencing LAMC2 significantly blocks tumor formation in orthotopic iCCA mouse models. Mechanistically, it promotes EGFR protein translation via interacting with nascent unglycosylated EGFR in the endoplasmic reticulum (ER), resulting in activated EGFR signaling. LAMC2-mediated EGFR translation also depends on its interaction with the ER chaperone BiP via their C-terminus. Together LAMC2 and BiP generate a binding "pocket" of nascent EGFR and facilitate EGFR translation. Consistently, LAMC2-high iCCA patients have poor prognosis in two iCCA cohorts. LAMC2-high iCCA cells are highly sensitive to EGFR tyrosine kinase inhibitors (TKIs) treatment both in vitro and in vivo. Together, these data demonstrate LAMC2 as an oncogenic player in iCCA by promoting EGFR translation and an indicator to identify iCCA patients who may benefit from available EGFR-targeted TKIs therapies.

Emotions, COVID-19 related thoughts and satisfaction with life during the critical period from control to relaxation.

Introduction: In the context of declining mortality rates and increasing infectivity, it has become unavoidable for the majority of individuals to experience a COVID-19 infection at some point. This study aimed to investigate the psychological well-being of the general population during China's transition period from strict control measures to relaxed policies in COVID-19 prevention and control, as well as the impact of COVID-19 related thoughts on emotion and life satisfaction during widespread infections. Methods: A cross-sectional study was conducted involving a sample size of 1578 participants. Participants completed self-report questionnaires assessing positive and negative emotions, thoughts about COVID-19, and satisfaction with life. Demographic characteristics such as sex, age, and education level were controlled for in the analysis. Results: The findings revealed that individuals who had been infected with COVID-19 (specifically the Omicron variant BA.5.2 or BF.7) reported lower levels of positive emotions compared to those who were uninfected or had recovered from the infection. There was a significant relationship between COVID-19-related thoughts, emotions, and life satisfaction. Positive COVID-19 related thoughts were found to mediate the relationship between negative emotions and satisfaction with life. Discussion: This study represents a comprehensive examination conducted in China, focusing on assessing the impact of the COVID-19 pandemic on the general population during the critical transition period from control to relaxation. Throughout this period, the number of infections experienced fluctuations, initially rising but eventually declining over a one-month span. In such a momentous historical period, maintaining a positive perspective on COVID-19 and its management becomes paramount in enhancing the emotional well-being, life satisfaction and overall well-being of individuals.

Facet Engineering and Pore Design Boost Dynamic Fe Exchange in Oxygen Evolution Catalysis to Break the Activity-Stability Trade-Off.

The oxygen evolution reaction (OER) plays a vital role in renewable energy technologies, including in fuel cells, metal-air batteries, and water splitting; however, the currently available catalysts still suffer from unsatisfactory performance due to the sluggish OER kinetics. Herein, we developed a new catalyst with high efficiency in which the dynamic exchange mechanism of active Fe sites in the OER was regulated by crystal plane engineering and pore structure design. High-density nanoholes were created on cobalt hydroxide as the catalyst host, and then Fe species were filled inside the nanoholes. During the OER, the dynamic Fe was selectively and strongly adsorbed by the (101̅0) sites on the nanohole walls rather than the (0001) basal plane, and at the same time the space-confining effect of the nanohole slowed down the Fe diffusion from catalyst to electrolyte. As a result, a local high-flux Fe dynamic equilibrium inside the nanoholes for OER was achieved, as demonstrated by the Fe57 isotope labeled mass spectrometry, thereby delivering a high OER activity. The catalyst showed a remarkably low overpotential of 228 mV at a current density of 10 mA cm-2, which is among the best cobalt-based catalysts reported so far. This special protection strategy for Fe also greatly improved the catalytic stability, reducing the Fe leaching amount by 2 orders of magnitude compared with the pure Fe hydroxide catalyst and thus delivering a long-term stability of 130 h. An assembled Zn-air battery was stably cycled for 170 h with a low discharge/charge voltage difference of 0.72 V.

Global Patterns of Agricultural Investment and Food Security: Evidence from the fDi Markets Database.

The number of hungry people is on the rise and more efforts are needed to improve the global food security status. The Food and Agriculture Organization (FAO) proposes more investment in the agricultural sector to boost production and alleviate hunger. However, there are fewer papers that distinguish enterprises investment from public investment. In this case, we take advantage of detailed investment data in the fDi Markets database to explore the global patterns of agricultural investment. In particular, we identify the top destination countries based on aggregate and sub-sectoral agricultural investment data. Then we investigate the relationship between agricultural investment and food security, which is measured by per capita protein intake. Finally, we propose some suggestions from the investment motivation perspective to help food-insecure countries to attract overseas investment. We find that developed countries are the primary sources of global agricultural investment and these sources have been becoming more diverse in the past decade. It implies the trend towards a more inclusive investment environment worldwide. However, the global distribution of agricultural investment is uneven as food-insecure countries only receive 20% of the global agricultural investment. The top three destination countries, USA, China, and Russia, have a relatively high food security level. In contrast, countries suffering from food insecurity receive fewer investment projects, and most of which are on a small scale. Given the limited socio-economic development status in food-insecure countries, it is essential for all levels of society to help them and contribute to ending hunger.

Filler-Integrated Composite Polymer Electrolyte for Solid-State Lithium Batteries.

Composite polymer electrolytes (CPEs) utilizing fillers as the promoting component bridge the gap between solid polymer electrolytes and inorganic solid electrolytes. The integration of fillers into the polymer matrices is demonstrated as a prevailing strategy to enhance Li-ion transport and assist in constructing Li+ -conducting electrode-electrolyte interface layer, which addresses the two key barriers of solid-state lithium batteries (SSLBs): low ionic conductivity of electrolyte and high interfacial impedance. Recent review articles have largely focused on the performance of a broad spectrum of CPEs and the general effects of fillers on SSLBs device. Recognizing this, in this review, after briefly presenting the categories of fillers (traditional and emerged) and the promoted ionic conducting mechanisms in CPEs, the progress in the interfacial structure design principle, with the emphasis on the crucial influence of filler size, concentration, and hybridization strategies on filler-polymer interface that is the most critical to Li-ion transport is assessed. The latest exciting advances on filler-enabled in situ generation of a Li+ -conductive layer at the electrode-electrolyte interface to greatly reduce the interfacial impedance are further elaborated. Finally, this review discusses the challenges to be addressed, outlines research directions, and provides a future vision for developing advanced CPEs for high-performing SSLBs.

S and O Co-Coordinated Mo Single Sites in Hierarchically Porous Tubes from Sulfur-Enamine Copolymerization for Oxygen Reduction and Evolution.

The highly efficient bifunctional catalyst for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) is the key to achieving high-performance rechargeable Zn-air batteries. Non-precious-metal single-atom catalysts (SACs) have attracted intense interest due to their low cost and very high metal atomic utilization; however, high-activity bifunctional non-precious-metal SACs are still rare. Herein, we develop a new nanospace-confined sulfur-enamine copolymerization strategy to prepare a new type of bifunctional Mo SACs with O/S co-coordination (Mo-O2S2-C) supported on the multilayered, hierarchically porous hollow tubes. The as-prepared catalyst can not only expose more active sites and facilitate mass transfer due to their combined micropores, mesopores, and macropores but also have the S/O co-coordination structure for optimizing the adsorption energies of the ORR intermediates. Its ORR activity is among the highest, and it shows a low overpotential of 324 mV for the OER at 10 mA cm-2 in all of the reported Mo-based catalysts. When assembled in a Zn-air battery, it exhibits a high maximal power density of 197.3 mW cm-2 and a long service life of 50 hours, superior to those of Zn-air batteries using commercial Pt/C+IrO2.

Panoramic view of microRNAs in regulating cancer stem cells.

Cancer stem cells (CSCs) are a subgroup of tumor cells, possessing the abilities of self-renewal and generation of heterogeneous tumor cell lineages. They are believed to be responsible for tumor initiation, metastasis, as well as chemoresistance in human malignancies. MicroRNAs (miRNAs) are small noncoding RNAs that play essential roles in various cellular activities including CSC initiation and CSC-related properties. Mature miRNAs with ∼22 nucleotides in length are generated from primary miRNAs via its precursors by miRNA-processing machinery. Extensive studies have demonstrated that mature miRNAs modulate CSC initiation and stemness features by regulating multiple pathways and targeting stemness-related factors. Meanwhile, both miRNA precursors and miRNA-processing machinery can also affect CSC properties, unveiling a new insight into miRNA function. The present review summarizes the roles of mature miRNAs, miRNA precursors, and miRNA-processing machinery in regulating CSC properties with a specific focus on the related molecular mechanisms, and also outlines the potential application of miRNAs in cancer diagnosis, predicting prognosis, as well as clinical therapy.

Mesoporous Single Crystals with Fe-Rich Skin for Ultralow Overpotential in Oxygen Evolution Catalysis.

The oxygen evolution reaction (OER) is a key reaction in water splitting and metal-air batteries, and transition metal hydroxides have demonstrated the most electrocatalytic efficiency. Making the hydroxides thinner for more surface commonly fails to increase the active site number, because the real active sites are the edges. Up to now, the overpotentials of most state-of-the-art OER electrocatalysts at a current density of 10 mA cm-2 (η10 ) are still larger than 200 mV. Herein, a novel design of mesoporous single crystal (MSC) with an Fe-rich skin to boost the OER is shown. The edges around the mesopores provide lots of real active sites and the Fe modification on these sites further improves the intrinsic activity. As a result, an ultralow η10 of 185 mV is achieved, and the turnover frequency based on Fe atoms is as high as 16.9 s-1 at an overpotential of 350 mV. Moreover, the catalyst has an excellent catalytic stability, indicated by a negligible current drop after 10 000 cyclic voltammetry cycles. The catalyst enables Zn-air batteries to run stably over 270 h with a low charge voltage of 1.89 V. This work shows that MSC materials can provide new opportunities for the design of electrocatalysts.

Single-Atom Co Doped in Ultrathin WO3 Arrays for the Enhanced Hydrogen Evolution Reaction in a Wide pH Range.

Owing to the scarcity of Pt, low-cost, stable, and efficient nonprecious metal-based electrocatalysts that can be applied in a wide pH range for the hydrogen evolution reaction (HER) are urgently required. Herein, a highly efficient and robust HER catalyst that is applicable at all pH values is fabricated, containing isolated Co-single atomic sites anchored in the self-supported WO3 arrays grown on Cu foam. At a current density of 10 mA cm-2, the HER overpotentials are 117, 105, and 149 mV at pH values of 0, 7, and 14, respectively, which are significantly lower than those of the undoped WO3, suggesting superior electrocatalytic H2-evolution activity at all pH values. The catalyst also exhibits long-term stability over a wide pH range, particularly in an acidic medium over 24 h, owing to the excellent anticorrosion properties of WO3. Density functional theory calculations prove that the enhanced HER activity is attributed to the isolated Co sites because these optimize the adsorption energy of H* species on WO3. Moreover, the high electrical conductivity of Co-doped WO3 and the three-dimensional array structure supported on the porous metal support afford a catalyst with suitable HER kinetics to enhance the catalytic performance.

Prevalence and Related Factors of Depression, Anxiety, Acute Stress, and Insomnia Symptoms Among Medical Staffs Experiencing the Second Wave of COVID-19 Pandemic in Xinjiang, China.

The prevalence and related factors of mental health impact among medical staffs who experienced the second wave of the COVID-19 pandemic in China is unknown. Therefore, this survey was conducted to investigate the prevalence and related factors of depressive, anxiety, acute stress, and insomnia symptoms in medical staffs in Kashi, Xinjiang, China during the second wave of the COVID-19 pandemic. A cross-sectional online survey was conducted among medical staffs working in First People's Hospital of Kashi, Xinjiang. The questionnaire collected demographic data and self-design questions related to the COVID-19 pandemic. The Impact of Events Scale-6, the Insomnia Severity Index, the Patient Health Questionnaire-9, the Generalized Anxiety Disorder Scale-7, the Perceived Social Support Scale, the Chinese Big Five Personality Inventory-15, and the Trait Coping Style Questionnaire were used to measure psychological symptoms or characteristics. Binary logistic regression was carried out to examine the associations between socio-demographic factors and symptoms of depression, anxiety, stress, and insomnia. In total, data from 123 participants were finally included, among which the prevalence rate of depressive, anxiety, acute stress, and insomnia symptoms is 60.2, 49.6, 43.1, and 41.1%, respectively. The regression model revealed that minority ethnicity, being worried about infection, spending more time on following pandemic information, and neurotic personality were positively associated with the mental health symptoms, while extraversion personality, higher education level, and better social support were negatively associated. In our study, the prevalence of mental health impact was high among medical staffs in Kashi, China who experienced the second wave of the COVID-19 pandemic. Several factors were found to be associated with mental health conditions. These findings could help identify medical staffs at risk for mental health problems and be helpful for making precise mental health intervention policies during the resurgence. Our study may pave way for more research into Xinjiang during the COVID-19 pandemic.

Loss of miR-192-5p initiates a hyperglycolysis and stemness positive feedback in hepatocellular carcinoma.

BACKGROUND: Emerging studies revealed that cancer stem cells (CSCs) possessed peculiar metabolic properties, which however remained largely unknown in hepatocellular carcinoma (HCC). Genetic silencing of liver-abundant miR-192-5p was a key feature for multiple groups of CSC-positive HCCs. We thus aimed to investigate essential metabolic features of hepatic CSCs via using HCCs with miR-192-5p silencing as a model. METHODS: Datasets from two independent HCC cohorts were used. Data integration analyses of miR-192-5p with metabolome and mRNA transcriptome data in HCC Cohort 1 were performed to investigate miR-192-5p related metabolic features, which was further validated in Cohort 2. Cellular and molecular assays were performed to examine whether and how miR-192-5p regulated the identified metabolic features. Co-culture systems consisting of HCC cells and LX2 (human hepatic stellate cell line) or THP1 (human monocyte cell line) were established to explore effects of the identified metabolic properties on stemness features of HCC cells via interacting with co-cultured non-tumor cells. RESULTS: High levels of glycolysis-related metabolites and genes were present in HCCs with low miR-192-5p and CSC-positive HCCs in two independent HCC cohorts. miR-192-5p knockout cells displayed CSC features and miR-192-5p loss led to an enhanced glycolytic phenotype via upregulating three bona fide targets, GLUT1 and PFKFB3 (two glycolytic enzymes) and c-Myc (regulating glycolytic genes' expression). Meanwhile, c-Myc suppressed miR-192-5p transcription, ensuring a low-miR-192-5p/high-c-Myc loop to maintain hyperglycolysis. Moreover, over-produced lactic acid from hyperglycolytic HCC cells stimulated the ERK phosphorylation of co-cultured LX2 and THP1 non-tumor cells partially via NDRG3 and MCT1, which in turn promoted cell malignancy and stemness of HCC cells. Consistently, HCC patients with low level of miR-192-5p in their tumor tissues and high level of NDRG3 or MCT1 in their non-tumor tissues had the shortest overall survival. CONCLUSIONS: In CSC-positive HCCs, miR-192-5p loss enhanced glycolysis and over produced lactate might further increase HCC malignant features via interacting with environmental non-tumor cells.

Comparison of blood lipid profile/thyroid function markers between unipolar and bipolar depressed patients and in depressed patients with anhedonia or suicidal thoughts.

BACKGROUND: This study aimed to investigate the differences in the serum levels of glucose, lipid, and thyroid function markers between unipolar and bipolar depressed patients, as well as the effect of anhedonia and suicidal thoughts on the levels of these biochemical parameters. METHODS: A total of 287 unmedicated depressed patients from January 2016 to December 2017 were included in this study, including 92 bipolar depressions and 195 unipolar depressions. Anhedonia was determined using the item 32 of Symptom Checklist (SCL-90). Suicide ideation was assessed by item 15 of SCL-90. RESULTS: The bipolar group had significantly lower lipid levels (including triglycerides, cholesterol, low-density lipoprotein cholesterol [LDL], very low-density lipoprotein cholesterol [VLDL]) and insulin resistance index but higher levels of prolactin, low triiodothyronine (T3) and free T3 (FT3) as well as higher incidence of anhedonia as compared with the unipolar group. Depressed patients with anhedonia had significantly higher LDL level than those without anhedonia. Depressed patients with suicidal thoughts had cholesterol and high-density lipoprotein cholesterol (HDL) level. The above-mentioned differences were confirmed by logistic regression analysis. Receiver operating characteristic curve (ROC) analysis showed that the area under the ROC curve (AUC) ranged from 0.546 to 0.685. CONCLUSION: Triglycerides, cholesterol, LDL, VLDL T3, FT3 levels were significantly different between unipolar and bipolar depressed patients, which might have the potential to be the markers for differential diagnosis. Patients with anhedonia had lower LDL level, while patients with suicidal thoughts had higher levels of cholesterol and HDL as compared with the corresponding control groups.

Hollow Multihole Carbon Bowls: A Stress-Release Structure Design for High-Stability and High-Volumetric-Capacity Potassium-Ion Batteries.

Potassium-ion batteries are potential alternatives to lithium-ion batteries for large-scale energy storage considering the low cost and high abundance of potassium. However, it is challenging to obtain stable electrode materials capable of undergoing long-term potassiation/depotassiation due to the high accumulated stress associated with the huge volume variation of the electrode. Here, we simulate the von Mises stress distributions of four different carbon three-dimensional models under an isotropic initial stress by the finite element method and reveal the critical role of the structure of a hollow multihole bowl on the strain-relaxation behavior. In this regard, nitrogen/oxygen codoped carbon hollow multihole bowls (CHMBs) are synthesized via hydrothermal carbonization coupled with an emulsion-templating strategy using biomass as the carbon source. Consistent with our simulation results, the CHMB anode remains stable for over 1000 cycles and delivers a high reversible capacity of 304 mAh g-1 at 0.1 A g-1. In addition to the reduced stress accumulation, the good electrochemical performances are also attributed to the surface capacitive mechanism and the shortened electron/ion transport distance in CHMBs. In particular, the CHMB composite electrode has a volumetric specific capacity 56% higher than that of hollow spheres due to the high tapped density of the bowl-shaped particles.

Occurrence, source, and risk assessment of atmospheric parent polycyclic aromatic hydrocarbons in the coastal cities of the Bohai and Yellow Seas, China.

Parent polycyclic aromatic hydrocarbons (PPAHs) in the ambient air of the coastal cities near the Bohai and Yellow Seas were measured over a full year. The range and geometric average of total PPAH29 (29 species) were 5.16-1.22 × 103 and 118 ng/m3, respectively, with 77 ±â€¯14% in a gaseous phase. The 16 priority components accounted for 90 ±â€¯4% of the total mass concentration. The incremental life cancer risk (ILCR) via inhalation exposure to the PPAHs (3.17 × 10-4) was underestimated by 80%, as only the priority PPAHs were considered. The air concentrations of PPAHs in the Bohai Sea area were generally higher (p < 0.01) than those in the Yellow Sea area. A significant increase (p < 0.01) in the levels of PPAHs and large fractions of high molecular weight (HMW) components were observed in winter. Absorption by particulate organic carbon dominated in gas-particle partitioning of the PPAHs, and the seasonal variations in gas-particle partitioning of the low and moderate molecular weight compounds were more noticeable relative to the HMW species. In summer, significantly higher concentrations of PPAHs were found in the daytime than during nighttime, while the opposite case occurred in winter (p < 0.05). The positive matrix factorization (PMF) results indicated greater contributions of coal and biomass combustion to the PPAH emissions in the coastal cities of the Bohai Sea area compared with the Yellow Sea area. The burning of coal and biomass served as the main source of PPAHs in winter, while traffic exhaust was the dominant source in other seasons. The potential source contribution function (PSCF) revealed the important impacts of the external inputs on the local PPAHs via air mass transport. The contributions of the resolved emission sources to the ILCR were clearly different from those of the mass concentrations, indicating the necessity for source-oriented risk assessments.

Characteristics and human inhalation exposure of ionic per- and polyfluoroalkyl substances (PFASs) in PM10 of cities around the Bohai Sea: Diurnal variation and effects of heating activity.

Atmospheric PM10 (particulate matter with aerodynamic diameter <10 µm) samples were collected in the cities along the Bohai Sea Rim during heating and non-heating periods, and ionic per- and polyfluoroalkyl species (PFASs) in the PM10 were measured. The total concentration of ionic PFASs ranged from 21.8 to 87.0 pg/m3, and the mean concentration of ionic PFASs during the day (42.6 pg/m3) was slightly higher than that at night (35.1 pg/m3). Generally, diurnal variations in the levels of ionic PFASs were consistent with those in the PM10 concentrations. Perfluorooctanoic acid (PFOA, 23.5-33.7%), perfluoropentanoic acid (PFPeA, 28.3-39.9%) and perfluorobutyric acid (PFBA, 17.1-20.1%) accounted for the dominant compositional contributions. Significant positive correlations (p < 0.05) between the main components of PFASs and O3 implied that oxidative degradation (O3 served as the main oxidant) in the period of non-heating may affect the short-chain PFASs. The clustering analysis of a 72-h backward trajectory indicated that cross-provincial transport contributed to ionic PFASs at the sampling sites. Compared with ingestion via daily diet, the inhalation of PM10 exhibited an insignificant contribution to the estimated average daily intakes (ADIs) of PFASs by different age groups. In addition, the calculated hazard ratios (HRs) for the non-cancer respiratory risk, based on the air concentrations of PFOA and perfluorooctane sulfonate (PFOS), also manifested lower non-cancer risk through inhalation exposure. CAPSULE: The effects of heating and non-heating activity and diurnal variation on the concentrations of PFASs, dominated by PFOA, PFPeA, and PFBA in PM10, were determined, and atmospheric trans-provincial input served as an important source.

Diffusion of size bidisperse spheres in dense granular shear flow.

Diffusion is an important particle behavior in granular flow. Although granular diffusion has been studied for decades, the diffusion of size bidisperse particles has not been well understood. In this paper, discrete element method simulations with the Lees-Edwards boundary condition are performed to quantify the relation between the diffusion coefficient (D) and flow parameters for size bidisperse spheres in dense granular flow. The influences of the shear rate (γ[over ̇]), the solids fraction (f), and the diameter ratio (D_{LS}) of particles on diffusion are studied. The effects of the friction coefficient (µ) and the restitution coefficient (e) are also investigated. The results indicate that while small particles diffuse faster than large particles in a binary system the volume weighted average diffusion coefficient is proportional to the shear rate and the square of the volume weighted average particle diameter, d^{2}, and it is inversely proportional to the solids fraction. The quantified relation is given as D=k_{d}γ[over ̇]d^{2}, where k_{d}=0.0186/f, and this relation is not sensitive to the diameter ratio for D_{LS}≤3. The diffusion coefficient is not sensitive to the friction coefficient except for the extreme condition where µ<0.1, and it is also not sensitive to the restitution coefficient between 0.3 and 0.9.

A self-standing silver/crosslinked-poly(vinyl alcohol) network with microfibers, nanowires and nanoparticles and its linear aggregation.

Silver/polymer nanocomposites have made inroads into the fields of electronic devices, thermally conductive materials, antimicrobial agents and sensors. Here, we present the hydrothermal synthesis of a novel three-dimensional self-standing silver/crosslinked-poly(vinyl alcohol) (Ag/crosslinked-PVA) hybrid network constructed by linking three different subunits, namely, microfibers, nanowires and nanoparticles. One-dimensional crosslinked-PVA-based microfibers act as the skeleton of the sponge. Ag nanoparticles are uniformly embedded in the interior of the microfibers, and Ag nanowires grow outward from the interior of the microfibers. This Ag/crosslinked-PVA multi-architecture has not be observed or reported in current state-of-the-art studies. We simultaneously carry out two types of reactions, chemical reduction of Ag+ ions and intermolecular crosslinking of PVA chains, in the synthesis under hydrothermal conditions. Ag nanoparticles are formed and dispersed in the crosslinked-PVA microspheres. Then, these Ag/crosslinked-PVA microspheres bridge each other, forming microchains and microfibers. Ultimately, linear aggregation, which has rarely been mentioned in the literature, occurs in some adjacent Ag nanoparticles in the microfibers, and the Ag nanoparticles reorganize into nanowires. The Ag/crosslinked-PVA network is shown to be converted into a Ag/C composite through annealing, which exhibits electrocatalytic activity for glucose oxidation and can be used as a self-supporting electrode in an antibacterial nonenzymatic glucose sensor.

Characteristics of perfluoroalkyl acids in atmospheric PM10 from the coastal cities of the Bohai and Yellow Seas, Northern China.

The concentration distributions, compositional profiles and seasonal variations of 17 perfluoroalkyl acids (PFAAs) in PM10 (particles with aerodynamic diameters < 10 µm) were determined in seven coastal cities of the Bohai and Yellow Seas. The detection rates of perfluorooctanoic acid (PFOA) and short-chain components (perfluoroalkyl carboxylic acids (PFCAs) with ≤7 carbon atoms and perfluoroalkane sulfonic acids (PFSAs) with ≤5 carbon atoms) were much higher than those of other long-chain PFAA species. The annual average concentration of total PFAAs in PM10 ranged from 23.6 pg/m3 to 94.5 pg/m3 for the sampling cities. The monthly mean concentrations of PFAAs in PM10 in some sampling cities reached a peak value in winter, while no significant seasonal differences presented in other cities. High concentrations of PFAAs in the northern cities generally occurred during the local heating period (from November to March). Generally, the dominant components of PFAAs were PFOA and perfluorobutyric acid (PFBA). Some significantly positive correlations (p < 0.01) between the 10 dominant components were revealed in the sampling cities, which implied similar sources and fate behaviors. Based on the simulated 72-hr backward trajectory tracking of air masses, the clustering results demonstrated the sampling cities were affected mainly by the atmospheric transport in sequence from the northwest, the southwest and the open seas, and many transport trajectories of air masses passed by the local fluorine chemical manufacturers in Liaoning, Shandong, Jiangsu, and Hubei Provinces. The estimated average daily intake (ADI) corresponding to the residents in different age groups indicated insignificant contributions to PFOA and perfluorooctane sulfonate (PFOS) exposures by inhalation of PM10 compared to ingestion by daily diet, while the higher ADI of PFOA than the reported levels for adults should be a concern. The calculated hazard ratios (HR) exhibited low noncancer risks by inhalation exposure to PFOA and PFOS in PM10.