Characterising polycyclic aromatic hydrocarbons in road dusts and stormwater in urban environments.

The presence of polycyclic aromatic hydrocarbons (PAHs) pollution on urban road surfaces is one of the major environmental concerns. However, knowledge on the distribution variability of PAHs in road dusts (RDS) and stormwater is limited, which would restrict the further risk evaluation and mitigation implementation of PAHs in road stormwater runoff. This study collected RDS samples and stormwater samples on fourteen urban roads in Shenzhen, China. This study investigated the variation of sixteen PAHs species in RDS and stormwater, and further evaluated the intrinsic and extrinsic factors which influence PAHs accumulation on urban road surfaces. The research outcomes showed significant differences on spatial distribution of PAHs in RDS and in stormwater. The land use types, industrial, commercial and port areas and vehicular volume have a positive relationship with PAHs abundance while dust particle size showed a negative correlation with PAHs abundance. For two phases in stormwater, fluctuation of PAHs with the rainfall duration in total dissolved solid (TDS) was more intensive than in dissolved liquid phase (DLP). This indicated when PAHs attached to RDS enter stormwater, most of PAHs still tend to be on solid particles than in liquid. The study outcomes are expected to contribute to efficient designs of PAHs polluted stormwater mitigation.

Cross-Linked Sodium Alginate as A Multifunctional Binder to Achieve High-Rate and Long-Cycle Stability for Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) hold great promise owing to the naturally abundant sodium resource and high safety. The research focus of SIBs is usually directed toward electrode materials, while the binder as an important component is rarely investigated. Herein, a cross-linked sodium alginate (SA)/graphene oxide (GO) binder is judiciously designed to serve as a robust artificial interphase on the surface of both anode and cathode of SIBs. Benefiting from the cross-linking continuous network structure as well as the highly hydrophilic nature, the SA-GO binder possesses a large tensile strength of 197.7 Mpa and a high ionic conductivity of 0.136 mS cm-1 , superior to pure SA (93.8 Mpa, 0.025 mS cm-1 ). Moreover, the structural design of SA-GO binder exhibits a strong binding ability to guarantee structural integrity during cycling. To demonstrate its effectiveness, polyanion-type phosphates (e.g., Na3 (VO)2 (PO4 )2 F) and chalcogenides (e.g., MoS2 , VS2 ) are adopted as cathode and anode materials of SIBs, respectively. As compared to traditional binders (e.g., PVDF, SA), electrodes with the SA-GO binder exhibits significantly increased rate capability and cycling stability, such as Na3 (VO)2 (PO4 )2 F (40 C fast-charge, 84% capacity retention after 1000 cycles). This work highlights the role of novel aqueous-based binders in developing next-generation sodium-storage devices.

Ultrastable Graphite-Potassium Anode through Binder Chemistry.

Graphite with abundant reserves has attracted enormous research interest as an anode of potassium-ion batteries (PIBs) owing to its high plateau capacity of 279 mAh g-1 at ≈0.2 V in conventional carbonate electrolytes. Unfortunately, it suffers from fast capacity decay during K+ storage. Herein, an ultrastable graphite-potassium anode is developed through binder chemistry. Polyvinyl alcohol (PVA) is utilized as a water-soluble binder to generate a uniform and robust KF-rich SEI film on the graphite surface, which can not only inhibit the electrolyte decomposition, but also withstand large volume expansion during K+ -insertion. Compared to the PVDF as binder, PVA-based graphite anode can operate for over 2000 cycles (running time of 406 days at C/3) with 97% capacity retention in KPF6 -based electrolytes. The initial Coulombic efficiency (ICE) of graphite anode is as high as 81.6% using PVA as the binder, higher than that of PVDF (40.1%). Benefiting from the strong adhesion ability of PVA, a graphite||fluorophosphate K-ion full battery is further built through 3D printing, which achieves a record-high areal energy of 8.9 mWh cm-2 at a total mass loading of 38 mg cm-2 . These results demonstrate the important role of binder in developing high-performance PIBs.

Characterizing polycyclic aromatic hydrocarbons on road dusts in Shenzhen, China: implications for road stormwater reuse safety.

Urban road stormwater reuse is one of the most effective ways to mitigate water resource shortage. However, due to a diversity of human activities such as traffic, various toxic pollutants can be deposited on road surfaces during dry periods and washed off during wet periods, threatening stormwater reuse safety. Among these pollutants, polycyclic aromatic hydrocarbons (PAHs) have been widely found in road stormwater. This study selected twelve road sites in Shenzhen, China, and investigated PAHs deposited on urban roads and their influential factors (traffic characteristics, land use and road surface condition). The research outcomes showed that high-molecular-weight PAH species (5-6 benzene rings) had higher concentrations and variability on spatial distributions than light-molecular-weight ones (2-4 benzene rings). Additionally, more PAHs were attached to dusts with small particle sizes (< 150 µm), and among influential factors, commercial land use showed a stronger correlation with PAHs distributions, regardless of particle sizes. Furthermore, it is noteworthy that traffic volume did not have an important influence on PAH generations on roads, while the source tracking results did indicate that traffic activities were the main contributor of PAHs. This implies that other traffic characteristics such as frequent go-and-stop activities might also contribute PAHs on roads. This means that areas with frequent traffic congestions could be the "hot spot" areas of PAHs, although the traffic volume might be not high. These research outcomes can provide useful insight into effective stormwater management and ensuring their reuse safety.

Bacterial Cytochrome P450 Catalyzed Post-translational Macrocyclization of Ribosomal Peptides.

Ribosomally synthesized and post-translationally modified peptides (RiPPs) are a fascinating group of natural products that exhibit diverse structural features and bioactivities. P450-catalyzed RiPPs stand out as a unique but underexplored family. Herein, we introduce a rule-based genome mining strategy that harnesses the intrinsic biosynthetic principles of RiPPs, including the co-occurrence and co-conservation of precursors and P450s and interactions between them, successfully facilitating the identification of diverse P450-catalyzed RiPPs. Intensive BGC characterization revealed four new P450s, KstB, ScnB, MciB, and SgrB, that can catalyze the formation of Trp-Trp-Tyr (one C-C and two C-N bonds), Tyr-Trp (C-C bond), Trp-Trp (C-N bond), and His-His (ether bond) crosslinks, respectively, within three or four residues. KstB, ScnB, and MciB could accept non-native precursors, suggesting they could be promising starting templates for bioengineering to construct macrocycles. Our study highlights the potential of P450s to expand the chemical diversity of strained macrocyclic peptides and the range of biocatalytic tools available for peptide macrocyclization.

A Mechanically Flexible Necklace-Like Architecture for Achieving Fast Charging and High Capacity in Advanced Lithium-Ion Capacitors.

Integration of fast charging, high capacity, and mechanical flexibility into one electrode is highly desired for portable energy-storage devices. However, a high charging rate is always accompanied by capacity decay and cycling instability. Here, a necklace-structured composite membrane consisting of micron-sized FeSe2 cubes uniformly threaded by carbon nanofibers (CNF) is reported. This unique electrode configuration can not only accommodate the volumetric expansion of FeSe2 during the lithiation/delithiation processes for structural robustness but also guarantee ultrafast kinetics for Li+ entry. At a high mass loading of 6.2 mg cm-2 , the necklace-like FeSe2 @CNF electrode exhibits exceptional rate capability (80.7% capacity retention from 0.1 to 10 A g-1 ) and long-term cycling stability (no capacity decay after 1100 charge-discharge cycles at 2 A g-1 ). The flexible lithium-ion capacitor (LIC) fabricated by coupling a pre-lithiated FeSe2 @CNF anode with a porous carbon cathode delivers impressive volumetric energy//power densities (98.4 Wh L-1 at 157.1 W L-1 , and 58.9 Wh L-1 at 15714.3 W L-1 ). The top performance, long-term cycling stability, low self-discharge rate, and high mechanical flexibility make it among the best LICs ever reported.

Genome-Wide Identification of the NAC Gene Family in Zanthoxylum bungeanum and Their Transcriptional Responses to Drought Stress.

NAC (NAM, ATAF1/2, and CUC2) transcription factors (TFs) are one of the largest plant-specific TF families and play a pivotal role in adaptation to abiotic stresses. The genome-wide analysis of NAC TFs is still absent in Zanthoxylum bungeanum. Here, 109 ZbNAC proteins were identified from the Z. bungeanum genome and were classified into four groups with Arabidopsis NAC proteins. The 109 ZbNAC genes were unevenly distributed on 46 chromosomes and included 4 tandem duplication events and 17 segmental duplication events. Synteny analysis of six species pairs revealed the closely phylogenetic relationship between Z. bungeanum and C. sinensis. Twenty-four types of cis-elements were identified in the ZbNAC promoters and were classified into three types: abiotic stress, plant growth and development, and response to phytohormones. Co-expression network analysis of the ZbNACs revealed 10 hub genes, and their expression levels were validated by real-time quantitative polymerase chain reaction (qRT-PCR). Finally, ZbNAC007, ZbNAC018, ZbNAC047, ZbNAC072, and ZbNAC079 were considered the pivotal NAC genes for drought tolerance in Z. bungeanum. This study represented the first genome-wide analysis of the NAC family in Z. bungeanum, improving our understanding of NAC proteins and providing useful information for molecular breeding of Z. bungeanum.

Expanded Sequence Space of Radical S-Adenosylmethionine-Dependent Enzymes Involved in Post-translational Macrocyclization.

Ribosomally synthesized and post-translationally modified peptides (RiPPs) represent one of the largest but primarily underexplored natural product families in bacteria. The genetically encoded nature of RiPPs simplifies the prediction and prioritization of their biosynthetic gene clusters (BGCs). We report a small peptide and enzyme co-occurrence analysis workflow (SPECO), which allowed us to identify 32 220 prospective rSAM-catalyzed RiPP BGCs from 161 954 bacterial genomes and prioritize 25 families with new biosynthetic architectures or precursor patterns. We characterized three new enzymes that respectively catalyze cysteine-glycine (BlaB), histidine-aliphatic side chain (ScaB), and tyrosine/histidine-arginine (VguB) cross-links. The cyclophane-forming enzyme ScaB exhibits broad substrate selectivity, allowing it to catalyze diverse triceptide formation. These results demonstrate the strength of the SPECO workflow in discovering new enzymes for peptide macrocyclization.

Al2 O3 -Assisted Confinement Synthesis of Oxide/Carbon Hollow Composite Nanofibers and Application in Metal-Ion Capacitors.

Hollow micro-/nanostructures are widely explored for energy applications due to their unique structural advantages. The synthesis of hollow structures generally involves a "top-down" casting process based on hard or soft templates. Herein, a new and generic confinement strategy is developed to fabricate composite hollow fibers. A thin and homogeneous atomic-layer-deposition (ALD) Al2 O3 layer is employed to confine the pyrolysis of precursor fibers, which transform into metal (or metal oxide)-carbon composite hollow fibers after removal of Al2 O3 . Because of the uniform coating by ALD, the resultant composite hollow fibers exhibit a hollow interior from heads to ends even if they are millimeter long. V, Fe, Co, and Ni-based hollow nanofibers, demonstrating the versatility of this synthesis method, are successfully synthesized. Because of the carbon constituent, these composite fibers are particularly useful for energy applications. Herein, the as-obtained hollow V2 O3 -C fiber membrane is employed as a freestanding and flexible electrode for lithium-ion capacitor. The device shows an impressive energy density and a high power density.

Alantolactone suppresses inflammation, apoptosis and oxidative stress in cigarette smoke-induced human bronchial epithelial cells through activation of Nrf2/HO-1 and inhibition of the NF-κB pathways.

BACKGROUND: It is well established that airway remodeling and inflammation are characteristics for chronic obstructive pulmonary disease (COPD). Moreover, cigarette smoke extract (CSE) promots inflammation, apoptosis and oxidative stress in COPD. And, there is evidence suggested that alantolactone (ALT), a sesquiterpene lactone isolated from Inula helenium, plays an adverse role in inflammation, apoptosis and oxidative stress. However, few studies have investigated the function and mechanism of ALT treatment on the COPD pathological process. METHODS: The levels of IL-1 ß, TNF-α, IL-6 and IFN-γ were examined by ELISA. Cells' apoptosis and caspase-3 activity were detected by Cell Death Detection PLUS enzyme-linked immunosorbent assay and caspase-Glo 3/7 Assay, respectively. The content of malondialdehyde (MDA) and superoxide dismutase (SOD) were determined by using MDA and SOD assay kits. Reactive oxygen species (ROS) generation was measured by DCFH-DA assay. Protein expression was assayed by Western blot. RESULTS: In the present study, we aimed to observe the protective effects of ALT against inflammation, apoptosis and oxidative stress in human bronchial epithelial Beas-2B and NHBE cells. Our results showed that different doses of CSE exposure induced Beas-2B and NHBE cell inflammatory cytokines IL-1 ß, TNF-α, IL-6 and IFN-γ expression, cell apoptosis, caspase-3 activity and mediated oxidative stress markers MDA, ROS and SOD levels, while ALT treatment counteracted the effects of CSE. Further studies suggested that ALT attenuated NF-κB pathway activation. ALT also activated the Nrf2/HO-1 signal pathway through promoting Nrf2 nuclear aggregation and downstream HO-1 protein expression. HO-1 inhibitor tin protoporphyrin IX (SnPP IX) reversed the effects of ALT on Beas-2B and NHBE cell inflammation, apoptosis and oxidative stress. CONCLUSIONS: The above results collectively suggested that ALT suppressed CSE-induced inflammation, apoptosis and oxidative stress by modulating the NF-ĸB and Nrf2/ HO-1 axis.

Integrated Ultrafine Co0.85 Se in Carbon Nanofibers: An Efficient and Robust Bifunctional Catalyst for Oxygen Electrocatalysis.

Transition-metal selenides are emerging as alternative bifunctional catalysts for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR); however, their activity and stability are still less than desirable. Herein, ultrafine Co0.85 Se nanoparticles encapsulated into carbon nanofibers (CNFs), Co0.85 Se@CNFs, is reported as an integrated bifunctional catalyst for OER and ORR. This catalyst exhibits a low OER potential of 1.58 V vs. reversible hydrogen electrode (RHE) (EJ=10, OER ) to achieve a current density (J) of 10 mA cm-2 and a high ORR potential of 0.84 V vs. RHE (EJ=-1, ORR ) to reach -1 mA cm-2 . Thus, the potential between EJ=10, OER and EJ=-1, ORR is only 0.74 V, indicating considerable bifunctional activity. The excellent bifunctionality can be attributed to high electronic conduction, abundant electrochemically active sites, and the synergistic effect of Co0.85 Se and CNFs. Furthermore, this Co0.85 Se@CNFs catalyst displays good cycling stability for both OER and ORR. This study paves a new way for the rational design of hybrid catalysts composed of transition-metal selenides and carbon materials for efficiently catalyzing OER and ORR.

[Research Progress and Application Prospect of Nerve Rehabilitation by Transcranial Electrical and Magnetic Stimulation].

Accidents or diseases may cause impairment or even loss of human motor function, among which stroke is a disease which is most likely to cause disability and seriously endangers social health. During recent years, as a new nerve regulation technology, non-invasive brain stimulation technology can achieve the application of nerve stimulation to the brain, induce and promote neuroplasticity and improve the excitability of cerebral cortex. Especially, transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation(TMS) have shown high therapeutic potential in motor rehabilitation. This paper summarizes the mechanism and progress of the research and application of tDCS and TMS in the field of neurorehabilitation. Its technical challenges and future development trends are provided as well.

Large-Area, Uniform, Aligned Arrays of Na3 (VO)2 (PO4 )2 F on Carbon Nanofiber for Quasi-Solid-State Sodium-Ion Hybrid Capacitors.

Sodium-vanadium fluorophosphate (Na3 V2 O2 x (PO4 )2 F3-2 x , NVPF, 0 ≤ x ≤ 1) is considered to be a promising Na-storage cathode material due to its high operation potentials (3.6-4 V) and minor volume variation (1.8%) during Na+ -intercalation. Research about NVPF is mainly focused on powder-type samples, while its ordered array architecture is rarely reported. In this work, large-area and uniform Na3 (VO)2 (PO4 )2 F cuboid arrays are vertically grown on carbon nanofiber (CNF) substrates for the first time. Owing to faster electron/ion transport and larger electrolyte-electrode contact area, the as-prepared NVPF array electrode exhibits much improved Na-storage properties compared to its powder counterpart. Importantly, a quasi-solid-state sodium-ion hybrid capacitor (SIHC) is constructed based on the NVPF array as an intercalative battery cathode and porous CNF as a capacitive supercapacitor anode together with the P(VDF-HFP)-based polymer electrolyte. This novel hybrid system delivers an attractive energy density of ≈227 W h kg-1 (based on total mass of two electrodes), and still remains as high as 107 Wh kg-1 at a high specific power of 4936 W kg-1 , which pushes the energy output of sodium hybrid capacitors toward a new limit. In addition, the growth mechanism of NVPF arrays is investigated in detail.

Mesopore-Induced Ultrafast Na+ -Storage in T-Nb2 O5 /Carbon Nanofiber Films toward Flexible High-Power Na-Ion Capacitors.

Hybrid Na-ion capacitors (NICs) are receiving considerable interest because they combine the merits of both batteries and supercapacitors and because of the low-cost of sodium resources. However, further large-scale deployment of NICs is impeded by the sluggish diffusion of Na+ in the anode. To achieve rapid redox kinetics, herein the controlled fabrication of mesoporous orthorhombic-Nb2 O5 (T-Nb2 O5 )/carbon nanofiber (CNF) networks is demonstrated via in situ SiO2 -etching. The as-obtained mesoporous T-Nb2 O5 (m-Nb2 O5 )/CNF membranes are mechanically flexible without using any additives, binders, or current collectors. The in situ formed mesopores can efficiently increase Na+ -storage performances of the m-Nb2 O5 /CNF electrode, such as excellent rate capability (up to 150 C) and outstanding cyclability (94% retention after 10 000 cycles at 100 C). A flexible NIC device based on the m-Nb2 O5 /CNF anode and the graphene framework (GF)/mesoporous carbon nanofiber (mCNF) cathode, is further constructed, and delivers an ultrahigh power density of 60 kW kg-1 at 55 Wh kg-1 (based on the total weight of m-Nb2 O5 /CNF and GF/mCNF). More importantly, owing to the free-standing flexible electrode configuration, the m-Nb2 O5 /CNF//GF/mCNF NIC exhibits high volumetric energy and power densities (11.2 mWh cm-3 , 5.4 W cm-3 ) based on the full device, which holds great promise in a wide variety of flexible electronics.

A Novel AdpA Homologue Negatively Regulates Morphological Differentiation in Streptomyces xiamenensis 318.

The pleiotropic transcriptional regulator AdpA positively controls morphological differentiation and regulates secondary metabolism in most Streptomyces species. Streptomyces xiamenensis 318 has a linear chromosome 5.96 Mb in size. How AdpA affects secondary metabolism and morphological differentiation in such a naturally minimized genomic background is unknown. Here, we demonstrated that AdpA Sx , an AdpA orthologue in S. xiamenensis, negatively regulates cell growth and sporulation and bidirectionally regulates the biosynthesis of xiamenmycin and polycyclic tetramate macrolactams (PTMs) in S. xiamenensis 318. Overexpression of the adpASx gene in S. xiamenensis 318 had negative effects on morphological differentiation and resulted in reduced transcription of putative ssgA, ftsZ, ftsH, amfC, whiB, wblA1, wblA2, wblE, and a gene encoding sporulation-associated protein (sxim_29740), whereas the transcription of putative bldD and bldA genes was upregulated. Overexpression of adpASx led to significantly enhanced production of xiamenmycin but had detrimental effects on the production of PTMs. As expected, the transcriptional level of the xim gene cluster was upregulated, whereas the PTM gene cluster was downregulated. Moreover, AdpA Sx negatively regulated the transcription of its own gene. Electrophoretic mobility shift assays revealed that AdpA Sx can bind the promoter regions of structural genes of both the xim and PTM gene clusters as well as to the promoter regions of genes potentially involved in the cell growth and differentiation of S. xiamenensis 318. We report that an AdpA homologue has negative effects on morphological differentiation in S. xiamenensis 318, a finding confirmed when AdpA Sx was introduced into the heterologous host Streptomyces lividans TK24.IMPORTANCE AdpA is a key regulator of secondary metabolism and morphological differentiation in Streptomyces species. However, AdpA had not been reported to negatively regulate morphological differentiation. Here, we characterized the regulatory role of AdpA Sx in Streptomyces xiamenensis 318, which has a naturally streamlined genome. In this strain, AdpA Sx negatively regulated cell growth and morphological differentiation by directly controlling genes associated with these functions. AdpA Sx also bidirectionally controlled the biosynthesis of xiamenmycin and PTMs by directly regulating their gene clusters rather than through other regulators. Our findings provide additional evidence for the versatility of AdpA in regulating morphological differentiation and secondary metabolism in Streptomyces.

Co3+ -Rich Na1.95 CoP2 O7 Phosphates as Efficient Bifunctional Catalysts for Oxygen Evolution and Reduction Reactions in Alkaline Solution.

Implementing sustainable energy conversion and storage technologies is highly reliant on crucial oxygen electrocatalysis, such as the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). However, the pursuit of low cost, energetic efficient and robust bifunctional catalysts for OER and ORR remains a great challenge. Herein, the novel Na-ion-deficient Na2-x CoP2 O7 catalysts are proposed to efficiently electrocatalyze OER and ORR in alkaline solution. The engineering of Na-ion deficiency can tune the electronic structure of Co, and thus tailor the intrinsically electrocatalytic performance. Among the sodium cobalt phosphate catalysts, the Na1.95 CoP2 O7 (NCPO5) catalyst exhibits the lowest ΔE (EJ10,OER -EJ-1,ORR ) of only 0.86 V, which favorably outperforms most of the reported non-noble metal catalysts. Moreover, the Na-ion deficiency can stabilize the phase structure and morphology of NCPO5 during the OER and ORR processes. This study highlights the Na-ion deficient Na2-x CoP2 O7 as a promising class of low-cost, highly active and robust bifunctional catalysts for OER and ORR.

Combined supplementation of Lactobacillus fermentum and Pediococcus acidilactici promoted growth performance, alleviated inflammation, and modulated intestinal microbiota in weaned pigs.

BACKGROUND: Probiotics are important for pigs to enhance health and intestinal development, which are potential alternative to antibiotics. Many studies have reported the functions of single bacterial strain as probiotic on the animals. In this study, we evaluated effects of combined probiotics on growth performance, inflammation and intestinal microbiota in weaned pigs. One hundred and eight pigs, weaned at 28 day old (7.12 ± 0.08 kg), were randomly divided into the 3 dietary treatments with 6 pens and 6 pigs per pen (half male and half female). The experimental period lasted for 28 days and treatments were as follows: i. CONTROL: basal diet; ii. Antibiotic: the basal diet plus 75 mg· kg- 1 chlortetracycline; and iii. Probiotics: basal diet plus 4% compound probiotics. RESULTS: Supplementation probiotics improved average daily gain over the entire 28 days (P < 0.01) and feed efficiency in the last 14 days (P < 0.05) compared with the other two groups. Both probiotics and antibiotic supplementation decreased concentrations of serum pro-inflammatory cytokines interleukin-6 (P < 0.05) and interferon-γ (P < 0.01). Probiotics group had greater abundance of Lactobacillus in the caecal digesta and Firmicutes in the colonic digesta, while both probiotics and antibiotic supplementation inhibited Treponema_2 and Anaerovibrio in the caecal digesta. Caecal acetic and propionic acid (P < 0.05) of probiotics group were higher than the other two groups, whereas concentrations of colonic lactic acid and propionic acid (P < 0.05) of antibiotic group were lower than control and probiotics groups. CONCLUSIONS: These findings suggest that combined supplementation of Lactobacillus fermentum and Pediococcus acidilactici regulate the gut health and improve the host ADG and F/G by decreasing serum pro-inflammatory factors (IL-6, IFN-γ), promoting beneficial bacteria (Lactobacillus in the caecal digesta and Firmicutes in the colonic digesta), enhancing production of short chain fatty acids, and inhibiting pathogens (Treponema_2, Anaerovibrio in the caecal digesta).

Antioxidative effect of melatonin on cryopreserved chicken semen.

This is a unique study because is the first time we are adding melatonin into an extender in order to determine its influence on cryopreserved chicken semen. The primary focus of our present study was to evaluate the influence of different concentrations of Melatonin on cryopreserved chicken semen. Semen samples were allocated into four treatments, being one control and three different combinations of antioxidants and after the freeze-thaw operation, the sperm motility, plasma membrane integrity, acrosome integrity, endogenous enzymes (GSH-Px, CAT, SOD), MDA and ROS of chicken spermatozoa were all evaluated. The collection of the semen samples was from 40 Arbor Acre roosters and this procedure was repeated twice a week and then mixed in an extender that contained different MEL treatments as follows: a diluent without MEL (control, M 0), a diluent comprising 0.125 mg/mL (M 0.125) 0.25 mg/mL, (M 0.25) and 0.5 mg/mL (M 0.5). It was revealed that the supplementation of the base extender with an optimal 0.25 mg/mL MEL led to a higher significant difference in the motility of chicken sperm (P < 0.01), higher acrosome integrity (P < 0.05) and a higher plasma membrane integrity (P < 0.01) when compared to the control group at post-thaw. Furthermore, when compared to the control group, 0.25 mg/mL MEL addition into the extender significantly enhanced the activity of endogenous enzymes (GSH-Px, CAT, and SOD) in the chicken spermatozoa at post-thaw (P < 0.05). Moreover, 0.5 mg/mL MEL supplementation into the extender enhanced the GSH-Px activity in the chicken spermatozoa when compared with the control group (P < 0.05) at post-thaw. In contrast, the addition of 0.25 mg/mL MEL into the extender resulted in a significantly lower MDA in comparison to the 0.125 mg/mL, 0.5 mg/mL MEL treatment group and the control group (P < 0.05). Also, compared to the control group, MEL concentration of 0.125 mg/mL and 0.5 mg/mL MEL into the extender resulted in a significantly low ROS concentration (P < 0.05) but the addition of 0.25 mg/mL MEL concentration resulted in a significantly lower ROS level when compared to the control group (P < 0.01). In summary, MEL improved the quality of cryopreserved chicken sperm quality by decreasing oxidative stress level and the most optimal concentration was 0.25 mg/mL.

Determinants of efficiency growth of county-level public hospitals-evidence from Chongqing, China.

BACKGROUND: The reform of county-level public hospitals is a breakthrough in the new era of healthcare reform in China and has attracted considerable attention since 2012. Continuous and efficient operations of hospital are primary concerns of this reform. To ensure the effectiveness of county-based intervention reform measures in Chongqing, it is significant to understand how hospital and county characteristics are associated with county-level public hospital efficiency due to significant development differences between counties. This study identifies the trajectory of hospital efficiency over time and determinants. It will also provide preliminary references for advancing reform. METHODS: This study employs data from the Chongqing Regional Health Information Platform, Chongqing Health and Family Planning Statistical Yearbook, and Chongqing Statistical Yearbook for 2012-2016. A three-level growth model is used to estimate the efficiency growth trajectories within the contexts of hospitals and counties. RESULTS: The intra-hospital level factors that affect the initial efficiency include government financial assistance, daily charge per bed, total assets turnover, number of hospital healthcare technicians, and medical costs per 100-yuan medical income. Inter-hospital variance is explained by hospital type. Inter-county level factors affecting the growth rate include the number of healthcare technicians per 1000 people and population density of the county. The interaction effect of the number of hospital healthcare technicians, hospital type, and number of healthcare technicians per 1000 people on hospital efficiency growth is significant. CONCLUSIONS: This study identifies determinants that contribute to efficiency changes in public county-hospitals over time by using a three-level growth model. The differences in efficiency are associated with intra-hospital, inter-hospital, and inter-county characteristics in Chongqing, which provides useful insight into government decision-making and the progress of reform. The stability and reasonable increase in the number of healthcare technicians in a county are the key factors that improve the efficiency. Further reform should focus on maternal and child healthcare hospitals for increasing investment and implementing government compensation.

Nickel-Based Bicarbonates as Bifunctional Catalysts for Oxygen Evolution and Reduction Reaction in Alkaline Media.

Oxygen electrocatalysis, including the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), is one of the most important electrochemical processes for sustainable energy conversion and storage technologies. Herein, nickel-based bicarbonates are, for the first time, developed as catalysts for oxygen electrocatalysis, and demonstrate superior electrocatalytic performance in alkaline media. Iron doping can significantly tune the real valence of nickel ions, and consequently tailor the electrocatalytic ability of bicarbonates. Among the nickel-based bicarbonates, Ni0.9 Fe0.1 (HCO3 )2 exhibits the highest bifunctional catalytic activity, with a potential difference of 0.86 V between the OER potential at a current density of 10 mA cm-2 and the ORR potential at a current density of -1 mA cm-2 , which outperforms most of the reported precious-metal-free catalysts. The present work provides new insights into exploring efficient catalysts for oxygen electrocatalysis, and it suggests that, in addition to the extensively studied transition metal hydroxides and oxides, bicarbonates and carbonates also show great potential as precious metal-free catalysts.