Dynamic covalent polymer engineering for stable and self-healing perovskite solar cells.

Perovskite films are susceptible to degradation during their service period due to their weak mechanical properties. Acylhydrazone-bonded waterborne polyurethane (Ab-WPU) was employed as dynamic covalent polymer engineering to develop self-healing perovskite solar cells (SHPSCs). Ab-WPU enhances the crystallinity of the perovskite film, passivates the defects of the perovskite film through functional groups, and demonstrates promising flexibility and mild temperature self-healing properties of SHPSCs. The champion efficiency of SHPSCs on rigid and flexible substrates reaches 24.2% and 21.27% respectively. The moisture and heat stability of devices were improved. After 1000 bending cycles, the Ab-WPU-modified flexible device can be restored to an efficiency of over 95% of its original efficiency by heating to 60 °C. This is because the dynamic acylhydrazone bond can be activated to repair perovskite film defects at a mild temperature of 60 °C as evidenced by in situ AFM studies. This strategy provides an effective pathway for dynamic self-healing materials in PSCs under operational conditions.

Structure and oxygen vacancy engineered CuCo-layered double oxide nanotube arrays as advanced bifunctional electrocatalysts for overall water splitting.

In recent years, as a green renewable energy production technology, electrochemical water splitting has demonstrated high development potential. Many materials have been reported as successful catalysts in the water-splitting field. However, it is still a huge challenge to produce bifunctional electrocatalysts for the efficient and sustainable generation of hydrogen and oxygen simultaneously. Herein, we successfully developed oxygen vacancies abundant CuCo layered double oxide (Ov-CuCo-LDO) hollow nanotube arrays (HNTAs) loaded on nickel foam as advanced electrocatalysts for total water splitting. When the current density was 10 mA cm-2, the Ov-CuCo-LDO HNTAs exhibited outstanding onset overpotentials of 53.9 and 72.5 mV for the hydrogen evolution and oxygen evolution reactions (HER and OER) in alkaline medium, respectively, because of the bimetallic synergistic effect between the cobalt and copper and the unique hollow porous structure. In addition, an as-assembled Ov-CuCo-LDO||Ov-CuCo-LDO electrolytic cell showed a small potential of 1.55 V to deliver a current density of 10 mA cm-2. Moreover, it also showed remarkable durability after long-term overall water splitting for more than 20 h. The research results in this paper are of great interest to practical applications of the water decomposition process, providing clear and in-depth insights into preliminary robust and efficient multifunctional electrocatalysts for overall water splitting.

Highly efficient OER catalyst enabled by in situ generated manganese spinel on polyaniline with strong coordination.

The oxygen evolution reaction (OER), as the rate-determining step of electrochemical water splitting, is extremely crucial, and thus it is a requisite to engineer feasible and effective electrocatalysts to shrink the reaction energy barrier and accelerate the reaction. Herein, monodisperse Mn3O4 nanoparticles on a PANI substrate were synthesized by polymerization and in situ oxidation. Combining Mn3O4 nanoparticles and PANI fibers can not only maximize the strong coupling effect and synergistic effect but also construct a well-defined three-dimensional structure with extensive exposed active sites, where the permeation and adherence of the electrolyte are made exceedingly feasible, thus displaying excellent OER activity. Benefiting from the outstanding structural stability, the resulting Mn3O4/PANI/NF is able to deliver a low overpotential of 262 mV at a current density of 10 mA cm-2, which outperforms the commercial RuO2 catalyst (275 mV) as well as presently reported representative Mn-based and PANI-based electrocatalysts and state-of-the-art OER electrocatalysts. The synthetic method for Mn3O4/PANI not only provides a brand-new avenue for the rational design of inorganic material/conductive polymer composites but also broadens the understanding of the mechanism of Mn-based catalysts for highly enhanced OER.

The factors affecting the physical development of neonates in pregnant women with or without gestational diabetes mellitus.

OBJECTIVES: To explore the factors affecting neonatal physical development in pregnant women with or without gestational diabetes mellitus (GDM). METHODS: The subjects were selected from the pregnant woman giving birth in 2nd Affiliated Hospital of Zhengzhou University, from November 2015 to May 2016. The age, occupation, education level, gestational age, body weight before pregnancy, body weight at delivery, body height, delivery pattern, GDM status of pregnant women and neonatal gender, birth weight (BW), chest circumference (CC), head circumference (HC) and birth length (BL) were collected through medical records and questionnaires. The clinical data were retrospectively analyzed and studied. RESULTS: The significant differences were found between women with GDM and without GDM in following neonatal variables (P<0.05): BW, CC, and HC. GDM status increased the incidence of macrosomia (OR = 2.241, 95% CI: 1.406-3.573), large CC (OR = 2.470, 95% CI: 1.687-3.6153). Gestational weight gain (GWG) above IOM guideline was risk factor for macrosomia (OR = 1.763, 95% CI:1.098-2.833), large HC (OR = 1,584, 95% CI: 1.093-2.296) and large CC (OR = 1.707, 95% CI:1.163-2.506). Underweight was risk factor for short BL (OR = 2.543, 95% CI:1.161-5.571) and small CC (OR = 1.901, 95% CI:1.064-3.394). Female neonate was prone to appear short BL(OR = 2.831, 95% CI: 1.478-5.422) and small HC (OR = 2.750, 95% CI: 1.413-5.350), and not likely to macrosomia (OR = 0.538, 95% CI: 0.343-0.843), longer BL (OR = 0.584, 95% CI: 0.401-0.850), large HC (OR = 0.501, 95% CI: 0.352-0.713), and (OR = 0.640, 95% CI: 0.446-0.917). For women with GDM, gestational age was an risk factor of neonatal BW (low BW: OR = 0.207, 95% CI: 0.085-0.503; macrosomia: OR = 1.637, 95% CI: 1.177-2.276), BL (short BL: OR = 0.376, 95% CI: 0.241-0.585; long BL: OR = 1.422, 95% CI: 1.054-1.919), HC (small HC: OR = 0.343, 95% CI: 0.202-0.583; large HC: OR = 1.399, 95% CI: 1.063-1.842) and CC (small CC: OR = 0.524, 95% CI: 0.374-0.733; large CC: OR = 1.485, 95% CI: 1.138-1.936). CONCLUSIONS: In our study, gestational age, GDM status, neonatal gender, GWG and pre-pregnancy body mass index (BMI) are associated the abnormal physical development of neonates. In women with GDM, gestational age was correlate with neonatal abnormal physical developments.

In-Situ Generated Trimetallic Molybdate Nanoflowers on Ni Foam Assisted with Microwave for Highly Enhanced Oxygen Evolution Reaction.

Oxygen evolution reaction (OER) is considered as a critical half-cell reaction of water splitting, the kinetics of which is sluggish even not favored, thus requiring highly active electrocatalysts to shrink the reaction energy barrier and improve the energy conversion efficiency. In this study, In-situ generated trimetallic molybdate nanoflowers on Ni foam by a straightforward and time-saving solvothermal method assisted with microwave, not only bring synergistic effect into full play between multiple metals, but also construct a well-defined nanoflower-like structure accompanied by larger specific area (273.3 m2 g-1 ) and smaller size than the pristine NiMoO4 . The resulting Ni0.9 Al0.1 MoO4 -NF requires a relatively low overpotential of 266 mV for OER at 10 mA cm-2 , which outperforms commercial RuO2 catalysts (274 mV). Such excellent performance compares favorably to most previously reported NiMoO4 -based electrocatalysts for OER. This work not only supplies a facile method to construct a well-defined nanoflower-like structure on foam, but also broadens our horizons into the mechanism of OER in alkaline conditions.

Ultrastable PtCo/Co3O4-SiO2 Nanocomposite with Active Lattice Oxygen for Superior Catalytic Activity toward CO Oxidation.

A nanostructural catalyst with long-term durability under harsh conditions is very important for an outstanding catalytic performance. Herein, a new ultrastable PtCo/Co3O4-SiO2 nanocatalyst was explored to improve the catalytic performance of carbon monoxide (CO) oxidation by virtue of the surface active lattice oxygen derived from strong metal-support interactions. Such a structure can overcome the issues of Co3O4-SiO2 inactivation by water vapor and the Pt inferior activity at low temperature. Further, Co3O4-SiO2 nanosheets endow superior structure stability under high temperatures of up to 800 °C, which gives long-term catalytic cyclability of PtCo/Co3O4-SiO2 nanocomposites for CO oxidation. Moreover, the large specific surface areas (294 m2 g-1) of the nanosheet structure can expose abundant surface active lattice oxygen, which significantly enhanced the catalytic activity of CO oxidation at 50 °C over 30 days without apparent aggregation of PtCo nanoparticles after 20 cycles from 50 to 400 °C. It can be expected to be a promising candidate as an ultrastable efficient catalyst.

Effect of Lactobacillus paracasei N1115 and fructooligosaccharides in nonalcoholic fatty liver disease.

INTRODUCTION: Nonalcoholic fatty liver disease (NAFLD) is a growing health concern worldwide. Administration of probiotics and prebiotics has been proposed as a convenient and effective treatment. Our study aims to evaluate the therapeutic benefits of Lactobacillus paracasei N1115 (N1115) and fructooligosaccharides (FOS) by examining the histopathogenesis and underlying molecular events of NAFLD. MATERIAL AND METHODS: An NAFLD mouse model was established by feeding C57BL/6 mice with a high-fat diet (HFD). N1115, FOS and synbiotics were administered for 16 weeks. RESULTS: N1115, FOS and synbiotics alleviated HFD-induced hepatic steato-sis and release of tumor necrosis factor-α, and slowed the progression of cirrhosis. Compared to the HFD group, these dietary supplements reduced serum total triglyceride and cholesterol, and appeared to decrease the fasting blood glucose and insulin. Intraperitoneal glucose tolerance tests, homeostatic model assessment of insulin resistance and real-time PCR showed that the regimens could overcome insulin resistance. These findings were associated with the transcriptional repression of inflammatory factors such as lipopolysaccharides, Toll-like receptor 4 and nuclear factor-κB. Lastly, N1115, FOS, and synbiotics improved the intestinal barrier functions and histologic integrity. This was accompanied by the restoration of the p38 MAPK pathway and in-creased expression of the tight junction components occludin-1 and claudin-1. CONCLUSIONS: N1115, FOS and synbiotics are effective in the prevention and treatment of NAFLD. Our data support the translation of these agents into clinical evaluation in human subjects with NAFLD and/or associated risk factors.

Morphologies Tuning of Polypyrrole and Thermoelectric Properties of Polypyrrole Nanowire/Graphene Composites.

Polypyrrole (PPy) with different morphologies (e.g., particles, nanotubes, and nanowires) were successfully prepared by adding or without adding different kinds of surfactants through a chemical oxidative polymerization method, respectively. The results show that the morphologies of PPy can be effectively controlled and have a significantly effects on their thermoelectric properties. The PPy nanowires exhibit the highest electrical conductivity and Seebeck coefficient among the various PPy morphologies, such as particles, nanotubes, and nanowires, so PPy nanowires were chosen to prepare PPy nanowire/graphene thermoelectric composites via a soft template polymerization method using cetyltrimethyl ammonium bromide as the template. Both electrical conductivity and Seebeck coefficient of the PPy nanowire/graphene composites increased as the content of graphene increases from 0 to 20 wt %, and as the measured temperature increases from 300 K to 380 K, which leds to the same trend for the power factor. A highest power factor of 1.01 µWm-1K-2 at ~380 K was obtained for the PPy nanowire/graphene composites with 20 wt % PPy nanowire, which is about 3.3 times higher than that of the pure PPy nanowire.

Thermoelectric Properties of Flexible PEDOT:PSS/Polypyrrole/Paper Nanocomposite Films.

Flexible poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/polypyrrole/paper (PEDOT:PSS/PPy/paper) thermoelectric (TE) nanocomposite films were prepared by a two-step method: first, PPy/paper nanocomposite films were prepared by an in situ chemical polymerization process, and second, PEDOT:PSS/PPy/paper TE composite films were fabricated by coating the as-prepared PPy/paper nanocomposite films using a dimethyl sulfoxide-doped PEDOT:PSS solution. Both the electrical conductivity and the Seebeck coefficient of the PEDOT:PSS/PPy/paper TE nanocomposite films were greatly enhanced from 0.06 S/cm to ~0.365 S/cm, and from 5.44 µV/K to ~16.0 µV/K at ~300 K, respectively, when compared to the PPy/paper TE nanocomposite films. The thermal conductivity of the PEDOT:PSS/PPy/paper composite film (0.1522 Wm-1K-1 at ~300 K) was, however, only slightly higher than that of the PPy/paper composite film (0.1142 Wm-1K-1 at ~300 K). As a result, the ZT value of the PEDOT:PSS/PPy/paper composite film (~1.85 × 10-5 at ~300 K) was significantly enhanced when compared to that of the PPy/paper composite film (~4.73 × 10-7 at ~300 K). The as-prepared nanocomposite films have great potential for application in flexible TE devices.

Cu(II)-Catalyzed ortho-Selective Aminomethylation of Phenols.

A Cu(II)-catalyzed ortho-selective functionalization of free phenols with trifluoroborates to afford Csp2-Csp3 coupling products under mild conditions has been developed. A variety of functional groups on the phenol and the potassium aminomethyltrifluoroborate substrates were found compatible, furnishing the corresponding products in moderate to excellent yields. A single-electron transfer radical coupling mechanism involving a six-membered transition state is proposed to rationalize the high levels of ortho-selectivity in the reaction. This protocol provides straightforward access to ortho-aminomethyl-substituted phenols, unnatural amino acids and other bioactive small molecules.

Interaction of DNA with aromatic hydrocarbons fraction in atmospheric particulates of Xigu District of Lanzhou, China.

Voluminously epidemiological studies show that the relationships exist between the air pollution and human health and cancer. Aromatic hydrocarbons (AHs) in air form a large class of organic pollutants, which are widely in environment and many of them are known to be carcinogenic and/or mutagenic and contribute to ambient air pollution. In the past decades, bioassays mainly have been used to evaluate the toxicity of chemical mixtures in atmospheric particulates or aqueous environment. However, it is well known that the covalent complexes formed by carcinogens with DNA may be exert negative results in bioassay. So the main aim of this paper is to develop an evaluation method of toxicity effects of chemical mixtures in atmospheric particulates from chemical standpoint. In this study, the in vitro interaction of the AHs with DNA was investigated by absorption, fluorescence and resonance light scattering (RLS) spectroscopic techniques. The results showed that the AHs in the atmospheric particulates could combine with calf thymus DNA (ctDNA) and herring sperm DNA (hsDNA) without being activated or metabolized by organism, respectively. Intercalation may be present in the mechanism of interaction. The binding constants of the AHs with ctDNA and hsDNA were 2.5 x 10(2) and 2.0 x 10(3), respectively, which indicated that the interaction of the AHs with hsDNA is stronger than that with ctDNA. In addition, the relationships of dose-effect between the total mole concentration of chemical components and the ability of binding ctDNA and hsDNA were confirmed. This research made it possible to study the toxicity effects of chemical mixtures in atmospheric particulates by chemical method. It is believed that the composition and contents of unknown AHs and the interaction of DNA with AHs in atmospheric particulates of Xigu District of Lanzhou City, China are first reported in the past twenty years.

Enhanced photoluminescence of morin-bovine serum albumin on porous anodized aluminum oxide.

In this paper, the photoluminescence (PL) of porous anodized aluminum oxide (AAO) impregnated with essentially nonfluorescent morin and morin-bovine serum albumin (BSA) was investigated for the first time, respectively. The evident PL bands similar to that of morin-Al3+ complex in solution were observed and the intensity of the latter with morin-BSA was much greater than that of the former with only morin. Moreover, the enhancement increased with the larger pore diameter of the AAO membranes. The appearance of PL bands might be ascribed to the formation of morin-Al complexes in the AAO pores with its inner wall involved. A likely orderly luminescent model was proposed to be responsible for the observed enhancing phenomena of PL due to the coexistence of morin and BSA in the AAO pores.

Development of a quantitative structure-property relationship model for predicting the electrophoretic mobilities.

Electrophoretic mobility (mu0) is the most important parameter governing the separation of solutes in capillary zone electrophoresis. In this paper, a new model was constructed by means of a multilayer neural network using extended delta-bar-delta (EDBD) algorithm to estimate complex property of electrophoretic mobilities of aliphatic carboxylates and amines from simpler experimental properties. The molecular weight (W), molecular volume (V), the code (+1 or -1) of acid and base and pK value were used as input parameters to predict electrophoretic mobility. The networks' architecture and the learning times were optimized. The optimum artificial neural networks (ANNs) could give excellent prediction results.

A highly sensitive assay for protein with dibromochloro-arsenazo-Al(3+) using resonance light scattering technique and its application.

A simple, sensitive and selective method has been developed for the determination of protein using resonance light scattering (RLS) technique. The method is based on the interaction of protein and arsenazo-DBC-Al(3+) in the pH range of 5.0-7.0, which causes a substantial enhancement of the resonance scattering signal of arsenazo-DBC-Al(3+) in the wavelength range of 300-550 nm with the maximum RLS platform at 405-420 nm. With this method, 2.50-50.00 mug ml(-1) of bovine serum albumin (BSA) and 2.50-60.00 mug ml(-1) of human serum albumin (HSA) can be determined, and the detection limits, calculated three times the standard deviation (S.D.) of six blank measurements, for BSA and HSA were 123.4 and 89.6 ng ml(-1), respectively. Moreover, the method is free from interference from many amino acids and metal ions. The method, with high sensitivity, selectivity and reproducibility, was satisfactorily applied to the determination of total protein in human serum samples. Mechanism studies indicated that arsenazo-DBC-Al(3+) could bind to BSA depending mainly on electrostatic forces, which results in enhanced RLS in the arsenazo-DBC-Al(3+)-protein system.