Chemical Synergic Stabilization of High Br-Content Mixed-Halide Wide-Bandgap Perovskites for Durable Multi-Terminal Tandem Solar Cells with Minimized Pb Leakage.

High Br-content mixed-halide perovskites with wide-bandgap (WBG) of 1.6-2.0 eV have showcased vast potential to be used in tandem solar cells. However, they often suffer from severe halide segregation, phase separation and ion migration issues, which would accelerate the decomposition of perovskites films, deteriorate the photovoltaic performance and even aggravate the lead leakage from damaged devices. Here, we report a novel chemical synergic interaction strategy to mitigate the abovementioned issues. A small amount of cationic ß-cyclodextrin, composed of multiple ammonium cations, chlorine ions and abundant hydroxyl functional groups, was introduced into WBG perovskites, which effectively stabilized the halide ions and homogenized the phase distribution, comprehensively passivated the defects,and efficiently immobilized the Pb2+ ions. Encouragingly, the cationic ß-cyclodextrin was universal and useful for different WBG perovskites, which favorably boosted the efficiencies by 10%-36% and extended the device operational stability to 2680 h. The integrated four-terminal or six-terminal all-perovskite tandem solar cells exhibited efficiencies up to 24.39% and 22.42%, respectively. We demonstrated the cationic ß-cyclodextrin-assisted internal chemical encapsulation effectively prevented the Pb leakage from severely damaged devices with only 5.63 ppb Pb leaching out. The target tandem solar cells with cationic ß-cyclodextrin modification also realized a Pb sequestration efficiency of 93.4%.

Diabetes prediction model based on GA-XGBoost and stacking ensemble algorithm.

Diabetes, as an incurable lifelong chronic disease, has profound and far-reaching effects on patients. Given this, early intervention is particularly crucial, as it can not only significantly improve the prognosis of patients but also provide valuable reference information for clinical treatment. This study selected the BRFSS (Behavioral Risk Factor Surveillance System) dataset, which is publicly available on the Kaggle platform, as the research object, aiming to provide a scientific basis for the early diagnosis and treatment of diabetes through advanced machine learning techniques. Firstly, the dataset was balanced using various sampling methods; secondly, a Stacking model based on GA-XGBoost (XGBoost model optimized by genetic algorithm) was constructed for the risk prediction of diabetes; finally, the interpretability of the model was deeply analyzed using Shapley values. The results show: (1) Random oversampling, ADASYN, SMOTE, and SMOTEENN were used for data balance processing, among which SMOTEENN showed better efficiency and effect in dealing with data imbalance. (2) The GA-XGBoost model optimized the hyperparameters of the XGBoost model through a genetic algorithm to improve the model's predictive accuracy. Combined with the better-performing LightGBM model and random forest model, a two-layer Stacking model was constructed. This model not only outperforms single machine learning models in predictive effect but also provides a new idea and method in the field of model integration. (3) Shapley value analysis identified features that have a significant impact on the prediction of diabetes, such as age and body mass index. This analysis not only enhances the transparency of the model but also provides more precise treatment decision support for doctors and patients. In summary, this study has not only improved the accuracy of predicting the risk of diabetes by adopting advanced machine learning techniques and model integration strategies but also provided a powerful tool for the early diagnosis and personalized treatment of diabetes.

Conjugated diamine cation based halide perovskitoid enables robust stability and high photodetector performance.

Low-dimensional lead halide materials have proved to be intrinsically stable semiconductor materials. However, the development of one-dimensional (1D) perovskites or perovskitoids with both robust water stability and high optoelectronic performance still faces significant challenges. Here, we report a new class of 1D (TzBIPY)Pb2X6 (X = Cl, Br, I) perovskitoids featuring a π-conjugated diamine cation (TzBIPY = 2,5-di(pyridin-4-yl)thiazolo[5,4-d]thiazole). The TzBIPY2+ cation with delocalized electrons directly contributes to the electronic structure and hence reduces the band gap. Especially, the Br-based material exhibits enhanced carrier separation and transport capacity, benefiting from the improved electronic conjugation together with a type II intramolecular heterojunction between conjugated organic cations and Pb-X octahedra. The (TzBIPY)Pb2Br6 photodetector exhibits an impressive photocurrent on/off ratio of 8.1 × 105, which is much superior to the previous three-dimensional (3D) perovskite benchmark. Additionally, the π-conjugated cations serve as dense protective shields for vulnerable Pb-X inorganic lattice against being attacked by water, thus demonstrating exceptional stability even immersed in water for over 3000 h.

Electrochemically chalcogenative annulation enabled construction of functionalized saturated N-heterocycles.

An efficient chalcogenative annulation strategy for constructing functionalized saturated N-heterocycles from unactivated alkenes with dichalcogenides under electrochemical conditions has been presented. This protocol is applicable to mono-, di- or tri-substituted alkenes, providing a straightforward pathway to aziridines, azetidines, pyrrolidines, and piperidines with high regioselectivity. Moreover, the strategy is qualified to realize the oxychalcogenation of alkenes as well.

CuBr2-mediated dehydrogenative [4+2] annulation of 1-naphthyl-1,3-indandiones and alkenes.

Intermolecular annulation reactions of 1-naphthyl-1,3-indandiones with alkenes proceed efficiently in the presence of a copper catalyst to generate spirocarbocycle compounds. Various spirocyclic molecules bearing an all-carbon quaternary center could be obtained by this novel method with good yields, excellent regioselectivity, and good functional group tolerance. A radical mechanism is proposed based on the HRMS analysis results of control experiments.

Dehydrogenative [4 + 2] Annulation of 1-Indanones with Alkynes Enabled by In-Situ-Generated Nickel Hydride.

A practical and effective nickel-catalyzed dehydrogenative [4 + 2] annulation of 1-indanones with alkynes was reported. In this protocol, nickel-catalyzed desaturation of 1-indanones and nickel hydride catalyzed coupling with alkynes were first incorporated. A cyclopentadiene-type nickel hydride species was generated in situ via ß-H elimination, and they subsequently reacted with a wide variety of alkynes to afford various benzo[a]fluorenone derivatives in good yields and regioselectivity.

First-principles calculation of structural, electronic, optical, and mechanical properties of SrVO3.

CONTEXT AND RESULTS : In this paper, the crystal structure, electronic, optical, and mechanical properties of SrVO3 have been systematically studied by first-principles calculation. The results show that the calculated lattice parameters are in good agreement with the experimental values of X-ray diffraction. The density of states is described in detail in this paper. By analyzing the crystal structure and electronic properties of SrVO3, the magnetic properties of SrVO3 are obtained from the one unpaired electrons of V and the exchange interaction between two V ions. At the same time, a detailed analysis of the optical properties of SrVO3 was conducted, and it was found that it is transparent in the visible light range. Finally, the mechanical properties of SrVO3 are calculated, which can provide some references for future research. COMPUTATIONAL METHOD: In this paper, a first-principles method based on density functional theory (DFT) is reported for PBE-GGA analysis using the plane wave-pseudo potential method in a quantum concentrate packet, U value of 7 eV to V-d and a U value of 2 eV to O-p, Grimme correction by DFT-D method. The k points in the Brillouin region are set to 4 × 4 × 4. The energy convergence criterion for self-consistent field calculation is set at 5.0 × 10-6 eV/atom, and the cutoff energy is 1170 eV. In this paper, the force acting on each atom is not more than 0.01 eV/Å, the maximum stress is not more than 0.02GPa, and the maximum atomic displacement is 5 × 10-4 Å.

Deficiency of CAMSAP2 impairs olfaction and the morphogenesis of mitral cells.

In developing olfactory bulb (OB), mitral cells (MCs) remodel their dendrites to establish the precise olfactory circuit, and these circuits are critical for individuals to sense odors and elicit behaviors for survival. However, how microtubules (MTs) participate in the process of dendritic remodeling remains elusive. Here, we reveal that calmodulin-regulated spectrin-associated proteins (CAMSAPs), a family of proteins that bind to the minus-end of the noncentrosomal MTs, play a crucial part in the development of MC dendrites. We observed that Camsap2 knockout (KO) males are infertile while the reproductive tract is normal. Further study showed that the infertility was due to the severe defects of mating behavior in male mice. Besides, mice with loss-of-function displayed defects in the sense of smell. Furthermore, we found that the deficiency of CAMSAP2 impairs the classical morphology of MCs, and the CAMSAP2-dependent dendritic remodeling process is responsible for this defect. Thus, our findings demonstrate that CAMSAP2 plays a vital role in regulating the development of MCs.

Palladium(II)-Catalyzed Norbornene-Mediated Selective meta-C-H Silylation for the Synthesis of Arylsilanes from Primary Benzamides.

A palladium(II)-catalyzed norbornene-mediated remote selective meta-C-H silylation of primary benzamides was developed for the synthesis of arylsilanes. Such a conversion provides access to a range of arylsilanes with exclusive selectivity using norbornene (NBE) as the meta-C-H activator. The amide directing group can be detached simultaneously through C-C bond cleavage or undergo a dehydration reaction pathway to form nitriles.

A Method for Predicting the Melting Temperature of Ionic Compounds.

Predicting the melting temperature of materials has always been a topic of great concern. This article proposes an alternative model for determining the melting temperature of materials based on the main idea of the Lindemann melting criterion combined with the first-principles calculations of density functional theory. To verify the accuracy of the melting model, this article selected typical ionic crystals of MgO and 10 alkali metal halides as the validation objects. The calculation results indicate that the melting temperature of the MgO crystals and I-VII compounds is in good agreement with the experimental results.

Hydrogen sulfide mitigates memory impairments via the restoration of glutamatergic neurons in a mouse model of hemorrhage shock and resuscitation.

Impaired long-term memory, a complication of traumatic stress including hemorrhage shock and resuscitation (HSR), has been reported to be associated with multiple neurodegenerations. The ventral tegmental area (VTA) participates in both learned appetitive and aversive behaviors. In addition to being prospective targets for the therapy of addiction, depression, and other stress-related diseases, VTA glutamatergic neurons are becoming more widely acknowledged as powerful regulators of reward and aversion. This study revealed that HSR exposure induces memory impairments and decreases the activation in glutamatergic neurons, and decreased ß power in the VTA. We also found that optogenetic activation of glutamatergic neurons in the VTA mitigated HSR-induced memory impairments, and restored ß power. Moreover, hydrogen sulfide (H2S), a gasotransmitter with pleiotropic roles, has neuroprotective functions at physiological concentrations. In vivo, H2S administration improved HSR-induced memory deficits, elevated c-fos-positive vesicular glutamate transporters (Vglut2) neurons, increased ß power, and restored the balance of γ-aminobutyric acid (GABA) and glutamate in the VTA. This work suggests that glutamatergic neuron stimulation via optogenetic assay and exogenous H2S may be useful therapeutic approaches for improving memory deficits following HSR.

Palladium/NBE-Catalyzed Regioselective C-H Silylation: Access to Divergent Silicon-Containing Indoles.

A palladium/norbornene (NBE)-catalyzed regioselective C-H silylation of free NH-indoles is reported. This protocol uses Pd(OAc)2 as the catalyst and Cu(OAc)2 as the oxidant, and the reaction relies on the control of NBE as a switch. The reaction tolerates various functional groups, and a series of silicon-containing indoles were directly synthesized in 30%-94% yields.

Synthesis of Fluoren-9-ones via Pd-Catalyzed Annulation of 2-Iodobiphenyls with Vinylene Carbonate.

A palladium-catalyzed reaction for intermolecular selective C-H cyclocarbonylation of 2-iodobiphenyls is described. Intriguingly, the vinylene carbonate acts as a carbon monoxide transfer agent to enable the annulation reaction. Moreover, as a versatile synthon, fluoren-9-one can be transformed into a variety of functionalized organic molecules, such as [1,1'-biphenyl]-2-carboxylic acid, 1'H,3'H-spiro[fluorene-9,2'-perimidine] and N-tosylhydrazones.

Band Structure Optimized by Electron-Acceptor Cations for Sensitive Perovskite Single Crystal Self-Powered Photodetectors.

Low-dimensional perovskites afford improved stability against moisture, heat, and ionic migration. However, the low dimensionality typically results in a wide bandgap and strong electron-phonon coupling, which is undesirable for optoelectronic applications. Herein, semiconducting A-site organic cation engineering by electron-acceptor bipyridine (bpy) cations (2,2'-bpy2+ and 4,4'-bpy2+) is employed to optimize band structure in low-dimensional perovskites. Benefiting from the merits of lower lowest unoccupied molecular orbital (LUMO) energy for 4,4'-bpy2+ cation, the corresponding (4,4'-bpy)PbI4 is endowed with a smaller bandgap (1.44 eV) than the (CH3NH3)PbI3 (1.57 eV) benchmark. Encouragingly, an intramolecular type II band alignment formation between inorganic Pb-I octahedron anions and bpy2+ cations favors photogenerated electron-hole pairs separation. In addition, a shortening distance between inorganic Pb-I octahedral chains in (4,4'-bpy)PbI4 single crystal (SC) can effectively promote carrier transfer. As a result, a self-powered photodetector based on (4,4'-bpy)PbI4 SC exhibits 131 folds higher on/off ratio (3807) than the counterpart of (2,2'-bpy)2Pb3I10 SC (29). The presented result provides an effective strategy for exporting novel organic cation-based low-dimensional perovskite SC for high-performance optoelectronic devices.

Pd(II)-Catalyzed tandem selective dehydrogenative [4+2] annulation of 2-methyl-1,3-cycloalkanediones with olefins.

A practical and effective palladium-catalyzed selective dehydrogenative [4+2] annulation of 2-methyl-1,3-cycloalkanediones with olefins was reported. The active 2-methylene-1,3-cycloalkanedione was in situ generated via Pd-catalyzed enolate oxidation processes, and it subsequently reacted with a wide variety of olefins to afford various polysubstituted dihydropyran derivatives in good to excellent yields.

Research on customer churn prediction and model interpretability analysis.

In recent years, with the continuous improvement of the financial system and the rapid development of the banking industry, the competition of the banking industry itself has intensified. At the same time, with the rapid development of information technology and Internet technology, customers' choice of financial products is becoming more and more diversified, and customers' dependence and loyalty to banking institutions is becoming less and less, and the problem of customer churn in commercial banks is becoming more and more prominent. How to predict customer behavior and retain existing customers has become a major challenge for banks to solve. Therefore, this study takes a bank's business data on Kaggle platform as the research object, uses multiple sampling methods to compare the data for balancing, constructs a bank customer churn prediction model for churn identification by GA-XGBoost, and conducts interpretability analysis on the GA-XGBoost model to provide decision support and suggestions for the banking industry to prevent customer churn. The results show that: (1) The applied SMOTEENN is more effective than SMOTE and ADASYN in dealing with the imbalance of banking data. (2) The F1 and AUC values of the model improved and optimized by XGBoost using genetic algorithm can reach 90% and 99%, respectively, which are optimal compared to other six machine learning models. The GA-XGBoost classifier was identified as the best solution for the customer churn problem. (3) Using Shapley values, we explain how each feature affects the model results, and analyze the features that have a high impact on the model prediction, such as the total number of transactions in the past year, the amount of transactions in the past year, the number of products owned by customers, and the total sales balance. The contribution of this paper is mainly in two aspects: (1) this study can provide useful information from the black box model based on the accurate identification of churned customers, which can provide reference for commercial banks to improve their service quality and retain customers; (2) it can provide reference for customer churn early warning models of other related industries, which can help the banking industry to maintain customer stability, maintain market position and reduce corporate losses.

Hemorrhagic Shock and Resuscitation Causes Excessive Dopaminergic Signaling in the mPFC and Cognitive Dysfunction.

Peri-operative hemorrhagic shock and resuscitation (HSR), a severe traumatic stress, is closely associated with post-operative anxiety, depression, and cognitive dysfunction, subsequently causing a serious burden on families and society. Following the co-release of corticotropin-releasing factor and catecholamine, traumatic stress activates dopaminergic neurons, increasing the addictive behavior and neurocognitive impairment risks. This study investigates the association between cognitive dysfunction and dopaminergic neurons in the mPFC under HSR conditions. This study established an HSR model by bleeding and re-transfusion in the mice. After HSR exposure, a dopamine D1 receptor antagonist, SKF-83566, was administered intraperitoneally for three consecutive days. Novel object recognition (NOR), conditioned fearing (FC), and conditioned place preference (CPP) were used to assess cognitive changes 16 days after HSR exposure. Local field potential (LFP) in the mPFC was also investigated during the novel object exploration. Compared with the mice exposed to sham, there was a significant decrease in the object recognition index, a reduction in context- and tone-related freezing time, an increase in CPP values, a downregulation of ß-power but upregulation of γ-power in the mPFC in the mice exposed to HSR. Moreover, the mice exposed to HSR showed significantly upregulated TH-positive cell number, cleaved caspase-1- and TH-positive cells, and interleukin (IL)-1ß/18 expression in the mPFC compared with sham; SKF-83566 could partially reverse these alternations. The HSR caused excessive dopaminergic signaling and cognitive dysfunction in the mPFC, a condition that might be ameliorated using a dopamine D1 receptor inhibitor.

NBE-Controlled Palladium-Catalyzed Intermolecular Selective C-H Silylation of Boronic Acids.

An efficient palladium-catalyzed intermolecular selective C-H silylation of boronic acids is described. The combination of palladium catalyst with copper oxidant enables ortho-selective C-H silylation by employing hexamethyldisilane as the trimethylsilyl source, which relies on the control of NBE derivatives as a switch, thus providing straightforward access to divergent organosilicon compounds.

NAD+ rescues aging-induced blood-brain barrier damage via the CX43-PARP1 axis.

Blood-brain barrier (BBB) function deteriorates during aging, contributing to cognitive impairment and neurodegeneration. It is unclear what drives BBB leakage in aging and how it can be prevented. Using single-nucleus transcriptomics, we identified decreased connexin 43 (CX43) expression in cadherin-5+ (Cdh5+) cerebral vascular cells in naturally aging mice and confirmed it in human brain samples. Global or Cdh5+ cell-specific CX43 deletion in mice exacerbated BBB dysfunction during aging. The CX43-dependent effect was not due to its canonical gap junction function but was associated with reduced NAD+ levels and mitochondrial dysfunction through NAD+-dependent sirtuin 3 (SIRT3). CX43 interacts with and negatively regulates poly(ADP-ribose) polymerase 1 (PARP1). Pharmacologic inhibition of PARP1 by olaparib or nicotinamide mononucleotide (NMN) supplementation rescued NAD+ levels and alleviated aging-associated BBB leakage. These findings establish the endothelial CX43-PARP1-NAD+ pathway's role in vascular aging and identify a potential therapeutic strategy to combat aging-associated BBB leakage with neuroprotective implications.

Response of peanut plant and soil N-fixing bacterial communities to conventional and biodegradable microplastics.

Microplastics (MPs) occur and distribute widely in agroecosystems, posing a potential threat to soil-plant systems. However, little is known about their effects on legumes and N-fixing microbes. Here, we explored the effects of high-density polyethylene (HDPE), polystyrene (PS), and polylactic acid (PLA) on the growth of peanuts and soil N-fixing bacterial communities. All MPs treatments showed no phytotoxic effects on plant biomass, and PS and PLA even increased plant height, especially at the high dose. All MPs changed soil NO3--N and NH4+-N contents and the activities of urease and FDAse. Particularly, high-dose PLA decreased soil NO3--N content by 97% and increased soil urease activity by 104%. In most cases, MPs negatively affected plant N content, and high-dose PLA had the most pronounced effects. All MPs especially PLA changed soil N-fixing bacterial community structure. Symbiotic N-fixer Rhizoboales were greatly enriched by high-dose PLA, accompanied by the emergence of root nodulation, which may represent an adaptive strategy for peanuts to overcome N deficiency caused by PLA MPs pollution. Our findings indicate that MPs can change peanut-N fixing bacteria systems in a type- and dose-dependent manner, and biodegradable MPs may have more profound consequences for N biogeochemical cycling than traditional MPs.