Enhanced Efficiency and Stability of Inverted Perovskite Solar Cells via Primary Amine Molecular Reaction.

The inverted perovskite solar cells have drawn considerable attention owing to their low cost, good compatibility, and easy production processes. However, the device performance is still limited by some important factors, such as surface imperfections and interfacial nonradiative recombination losses. Here, N-acetylethylenediamine (N-AE) is introduced to bind to the surface of the perovskite film via an ammonia condensation reaction. This process creates a stable interfacial layer with n-type doping to enhance the open-circuit voltage (VOC). Moreover, during post-treatment, N-AE dissolves a portion of the perovskite on the surface, leading to perovskite recrystallization. This process enhances the surface quality of the perovskite film and reduces nonradiative recombination. As a result, the inverted perovskite solar cell exhibits a power conversion efficiency approaching 20%, with a rise in VOC from 0.96 to 1.05 V. More impressively, the unencapsulated devices display excellent stability at 85 °C annealing and retained 88% of the initial PCE for 816 h.

Ammonia-assisted Ni particle preferential deposition in Ni-Fe pyrophosphates on iron foam to improve the catalytic performance for overall water splitting.

Designing efficient and cost-effective electrocatalysts for overall water splitting remains a major challenge in hydrogen production. Herein, ammonia was introduced to pyrophosphate chelating solution assisted Ni particles preferential plating on porous Fe substrate to form coral-like Ni/NiFe-Pyro electrode. The pyrophosphate with multiple complex sites can couple with nickel and iron ions to form an integrated network structure, which also consists of metallic nickel due to the introduction of ammonia. The large network structure in Ni/NiFe-Pyro significantly enhances the synergistic effect between nickel and iron and then improves the electrocatalytic performance. As a result, the coral-like Ni/NiFe-Pyro@IF exhibits good electrocatalytic activity and stability for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). The electrolyzer assembled with Ni/NiFe-Pyro@IF as cathode and anode just needs a low water-splitting voltage of 1.54 V to obtain the current density of 10 mA cm-2. Meanwhile, the stability test of Ni/NiFe-Pyro@IF is performed at the current densities ranging from 10 to 400 mA cm-2 for 50 h without any significant decay, indicating robust catalytic stability for overall water splitting. This strategy for synthesizing metal/metal pyrophosphate composites may provide a new avenue for future studies of efficient bifunctional electrocatalysts.

Enhanced Resonance for Facilitated Modulation of Large-Area Perovskite Films with Stable Photovoltaics.

Upscaling efficient and stable perovskite films is a challenging task in the industrialization of perovskite solar cells partly due to the lack of high-performance hole transport materials (HTMs), which can simultaneously promote hole transport and regulate the quality of perovskite films especially in inverted solar cells. Here, a novel HTM based on N-C = O resonance structure is designed for facilitating the modulation of the crystallization and bottom-surface defects of perovskite films. Benefiting from the resonance interconversion (N-C = O and N+ = C-O- ) in donor-resonance-donor (D-r-D) architecture and interactions with uncoordinated Pb2+ in perovskite, the resulting D-r-D HTM with two donor units exhibits not only excellent hole extraction and transport capacities, but also efficient crystallization modulation of perovskite for high-quality photovoltaic films in large area. The D-r-D HTM-based large-area (1.02 cm2 ) devices exhibit high power conversion efficiencies (PCEs) up to 21.0%. Moreover, the large-area devices have excellent photo-thermal stability, showing only a 2.6% reduction in PCE under continuous AM 1.5G light illumination at elevated temperature (≈65 °C) for over 1320 h without encapsulation.

Polyaniline-modified halloysite nanotubes as high-efficiency adsorbents for removing of naproxen in the presence of different heavy metals.

In this work, novel adsorbent polyaniline-modified halloysite nanotubes (HNT@PA-2) were synthesized successfully by in situ polymerization to increase active adsorption sites. With the increase of the amount of aniline, the adsorption capacity of naproxen becomes higher. The optimal ratio of halloysite nanotubes to aniline was 1 : 2. The effects of adsorption conditions such as pH, mass of HNT@PA-2, time and initial concentration of naproxen were systematically researched. The optimum adsorption for naproxen was pH 9, mass 10 mg and contact time 4 h. The adsorption of naproxen conformed to the pseudo-first-order kinetic model, and the maximum adsorption capacity was 242.58 mg g-1 at 318 K. In addition, the effects of ionic strength and different heavy metals also were studied. Higher ionic strength of the system could influence the adsorption of naproxen. The effects of Al3+, Pb2+, Zn2+ and Co2+ ions on the adsorption of naproxen could be ignored, while Cu2+ and Fe3+ ions inhibited the process. The mechanisms for naproxen adsorbed by the HNT@PA-2 were π-π interaction, hydrogen bonding and hydrophobic reaction. Therefore, the HNT@PA-2 could be used for the treatment of medical wastewater for removing naproxen.

Sedative and adverse effect comparison between oral midazolam and nitrous oxide inhalation in tooth extraction: a meta-analysis.

OBJECTIVE: Oral midazolam and nitrous oxide inhalation were commonly used sedative and analgesic techniques during tooth extraction. It is still controversial whether oral midazolam can replace the nitrous oxide inhalation for sedative and analgesic treatment of tooth extraction. Therefore, we conducted this study in order to provide a reference for doctors to choose effective sedative and analgesic treatment in tooth extraction. METHODS: We searched the Chinese and English databases including PubMed, Embase, the Cochrane Library, China National Knowledge Infrastructure, Wanfang and VIP information databases. RESULTS: Through this meta-analysis, we found that the success rate of sedation and analgesia treatment with oral midazolam during tooth extraction was 75.67% and the incidence of adverse reactions was 21.74%. The success rate of sedation and analgesia treatment using nitrous oxide inhalation during tooth extraction was 93.6% and the incidence of adverse reactions was 3.95%. CONCLUSION: The use of nitrous oxide inhalation for sedation and analgesia during tooth extraction is very effective, and oral midazolam can be used as an alternative to nitrous oxide inhalation.

Synthesis and characterization of a julolidine-based electro-optic molecular glass.

AIM: Organic electro-optic (EO) materials have recently gained considerable attention owing to their advantages compared to inorganic EO materials. Among different kinds of organic EO materials, organic EO molecular glass exhibits desired prospect because of its high chromophore loading density and large macroscopic EO activity. INTRODUCTION: The objective of this study is to design and synthesize a novel organic EO molecular glass JMG utilizing julolidine moiety as the electron donor, thiophene moiety as the conjugated bridge, trifluoromethyl substituted tricyanofuran derivate (Ph-CF3-TCF) as the electron acceptor. METHOD: The JMG's structure was characterized through NMR and HRMS. The photophysical property, glass transition temperature, first hyperpolarizability (ß) and dipole moment (µ) of JMG were determined through UV-vis spectra, DSC test and DFT calculation. RESULTS: JMG's Tg reached to 79 °C and it can form high-quality optical film. The theoretical calculation shows that the first hyperpolarizability (ß) and dipole moment (µ) of JMG were calculated to 730×10-30 esu and 21.898 D. After connecting poling with the poling voltage of 49 V/µm at 90 ℃for 10 min, the highest EO coefficient (r33) of the poled JMG films reached to 147 pm/V. CONCLUSION: A novel julolidine-based NLO chromophore with two tert-butyldiphenylsilyl (TBDPS) groups was successfully prepared and characterized. TBDPS group is introduced as the film-forming group, and it also plays the role of isolation group, which can suppress the electrostatic interaction between chromophores, improve the poling efficiency and further enhance the EO activity. The excellent performances endow JMG with potential applications in device fabrication.

The potential thermoelectric material Tl3XSe4 (X = V, Ta, Nb): a first-principles study.

Searching for materials with a high thermoelectric figure of merit (ZT) has always been the goal of scientific researchers in the energy field. Here, we combine first-principles calculations to obtain the thermoelectric characteristics of Tl3XSe4 (X = V, Nb, or Ta). First, we compared the phonon thermal transport characteristics of Tl3XSe4 by solving the Boltzmann transport equation and calculated the thermal conductivity. After that, we obtained the thermoelectric properties of Tl3XSe4 through the relaxation time approximation theory. The results show that Tl3XSe4 has a high Seebeck coefficient, high electrical conductivity, high power factor (PF) and low thermal conductivity contributed by both phonons and electrons. At the same time, the ZT value of Tl3XSe4 shows that it is a potential thermoelectric material with excellent performance. This work demonstrates the thermoelectric transport characteristics of Tl3XSe4 to explore its potential applications in many other fields of thermoelectricity and energy.

Tobacco and oral squamous cell carcinoma: A review of carcinogenic pathways.

INTRODUCTION: Tobacco is one of the most important risk factors for premature death globally. More than 60 toxic chemicals in tobacco can invade the body's various systems. Oral squamous cell carcinoma (OSCC) is a pathological type of oral cancer, accounting for over 90% of oral cancers. A vast quantity of scientific, clinical and epidemiological data shows that tobacco is associated with the development of oral squamous cell carcinoma, and its carcinogenic pathways may be complicated. METHODS: We conducted a thorough electronic search by Cochrane, EMBASE and PubMed to identify relevant studies. Studies published up to the end of October 2018 were included. After assessing and selecting articles based on eligibility criteria, studies were classified and elaborated according to the pathogenesis. RESULTS: Tobacco as an important risk factor can cause epigenetic alteration of oral epithelial cells, inhibit multiple systemic immune functions of the host, and its toxic metabolites can cause oxidative stress on tissues and induce OSCC. In addition, some specific viruses such as EBV and HPV are thought to play a role in the development of OSCC. CONCLUSIONS: Oral cancer ranks eighth among the most common causes of cancer-related deaths worldwide, and tobacco is one the most important carcinogenic factors of OSCC. This review of the literature attempts to provide directions and ideas for future related research, and emphasizes the need for efforts to reduce tobacco consumption.

Machine Learning Models Combined with Virtual Screening and Molecular Docking to Predict Human Topoisomerase I Inhibitors.

In this work, random forest (RF), support vector machine, k-nearest neighbor and C4.5 decision tree, were used to establish classification models for predicting whether an unknown molecule is an inhibitor of human topoisomerase I (Top1) protein. All these models have achieved satisfactory results, with total prediction accuracies from 89.70% to 97.12%. Through comparative analysis, it can be found that the RF model has the best forecasting effect. The parameters were further optimized to generate the best-performing RF model. At the same time, features selection was implemented to choose properties most relevant to the inhibition of Top1 from 189 molecular descriptors through a special RF procedure. Subsequently, a ligand-based virtual screening was performed from the Maybridge database by the optimal RF model and 596 hits were picked out. Then, 67 molecules with relative probability scores over 0.7 were selected based on the screening results. Next, the 67 molecules above were docked to Top1 using AutoDock Vina. Finally, six top-ranked molecules with binding energies less than -10.0 kcal/mol were screened out and a common backbone, which is entirely different from that of existing Top1 inhibitors reported in the literature, was found.

[Triterpenoid saponins from roots of Phytolacca acinosa].

A new triterpenoid saponin named esculentoside U(1), along with the five known compounds, was isolated and characterized from the roots of Phytolacca acinosa, a commonly used traditional Chinese medicine with anti-inflammatory and anti-rheumatoid activities. The structure of the new saponin was elucidated as 3-O-[ß-D-glucopyranosyl-(1→4)]-ß-D-xylopyranosyl]-2, 23-dihydroxyolean-11, 13(18)-diene-28, 29-dioic acid 29-methyl ester(1). The assignment of all NMR signals of 1 was performed by means of 2D-NMR experiments.