Multi-angle laser device improves novice learning of C-arm fluoroscopy for lumbar spine surgery.

PURPOSE: This study aims to evaluate the efficacy and satisfaction of using a multi-angle laser device (MLD) for C-arm fluoroscopy to assist novice learners during lumbar spine surgery. METHODS: Forty novice learners were randomly assigned to Group A using an MLD-equipped C-arm or Group B using a traditional C-arm. Both groups performed X-ray fluoroscopy on a lumbar spine model in supine and rotated positions. Time, number of shots, and deviation from the target were compared. A questionnaire was used to assess the learning experience. RESULTS: Group A required less time (13.66 vs. 25.63 min), and fewer shots (15.05 vs. 32.50), and had a smaller deviation (22.9% vs. 61.5%) than Group B (all p<0.05). The questionnaire revealed higher scores in Group A for comfort, efficiency, and knowledge mastery (all p<0.05). CONCLUSION: The MLD significantly improves novice learning of C-arm fluoroscopy during lumbar spine surgery.

Surface Lattice Modulation Enables Stable Cycling of High-Loading All-solid-state Batteries at High Voltages.

Halide solid electrolytes, known for their high ionic conductivity at room temperature and good oxidative stability, face notable challenges in all-solid-state Li-ion batteries (ASSBs), especially with unstable cathode/solid electrolyte (SE) interface and increasing interfacial resistance during cycling. In this work, we have developed an Al3+-doped, cation-disordered epitaxial nanolayer on the LiCoO2 surface by reacting it with an artificially constructed AlPO4 nanoshell; this lithium-deficient layer featuring a rock-salt-like phase effectively suppresses oxidative decomposition of Li3InCl6 electrolyte and stabilizes the cathode/SE interface at 4.5 V. The ASSBs with the halide electrolyte Li3InCl6 and a high-loading LiCoO2 cathode demonstrated high discharge capacity and long cycling life from 3 to 4.5 V. Our findings emphasize the importance of specialized cathode surface modification in preventing SE degradation and achieving stable cycling of halide-based ASSBs at high voltages.

Integrated Surface Modulation of Ultrahigh Ni Cathode Materials for Improved Battery Performance.

Ni-rich layered cathodes with ultrahigh nickel content (≥90%), for example LiNi0.9 Co0.1 O2 (NC0.9), are promising for next-generation high-energy Li-ion batteries (LIBs), but face stability issues related to structural degradation and side reactions during the electrochemical process. Here, surface modulation is demonstrated by integrating a Li+ -conductive nanocoating and gradient lattice doping to stabilize the active cathode efficiently for extended cycles. Briefly, a wet-chemistry process is developed to deposit uniform ZrO(OH)2 nanoshells around Ni0.905 Co0.095 (OH)2 (NC0.9-OH) hydroxide precursors, followed by high temperature lithiation to create reinforced products featuring Zr doping in the crust lattice decorated with Li2 ZrO3 nanoparticles on the surface. It is identified that the Zr4+ infiltration reconstructed the surface lattice into favorable characters such as Li+ deficiency and Ni3+ reduction, which are effective to combat side reactions and suppress phase degradation and crack formation. This surface control is able to achieve an optimized balance between surface stabilization and charge transfer, resulting in an extraordinary capacity retention of 96.6% after 100 cycles at 1 C and an excellent rate capability of 148.8 mA h g-1 at 10 C. This study highlights the critical importance of integrated surface modulation for high stability of cathode materials in next-generation LIBs.

Surface Lattice Modulation through Chemical Delithiation toward a Stable Nickel-Rich Layered Oxide Cathode.

Nickel-rich layered oxides (NLOs) are considered as one of the most promising cathode materials for next-generation high-energy lithium-ion batteries (LIBs), yet their practical applications are currently challenged by the unsatisfactory cyclability and reliability owing to their inherent interfacial and structural instability. Herein, we demonstrate an approach to reverse the unstable nature of NLOs through surface solid reaction, by which the reconstructed surface lattice turns stable and robust against both side reactions and chemophysical breakdown, resulting in improved cycling performance. Specifically, conformal La(OH)3 nanoshells are built with their thicknesses controlled at nanometer accuracy, which act as a Li+ capturer and induce controlled reaction with the NLO surface lattices, thereby transforming the particle crust into an epitaxial layer with localized Ni/Li disordering, where lithium deficiency and nickel stabilization are both achieved by transforming oxidative Ni3+ into stable Ni2+. An optimized balance between surface stabilization and charge transfer is demonstrated by a representative NLO material, namely, LiNi0.83Co0.07Mn0.1O2, whose surface engineering leads to a highly improved capacity retention and excellent rate capability with a strong capability to inhibit the crack of NLO particles. Our study highlights the importance of surface chemistry in determining chemical and structural behaviors and paves a research avenue in controlling the surface lattice for the stabilization of NLOs toward reliable high-energy LIBs.

Adsorption of 2-hydroxynaphthalene, naphthalene, phenanthrene, and pyrene by polyvinyl chloride microplastics in water and their bioaccessibility under in vitro human gastrointestinal system.

The interaction of microplastics (MPs) and organic pollutants has recently become a focus of investigation. To understand how microplastic residues affect the migration of organic pollutants, it is necessary to examine the adsorption and desorption behavior of organic pollutants on MPs. In this study, integrated adsorption/desorption experiments and theoretical calculations were used to clarify the adsorption mechanism of 2-hydroxynaphthalene (2-OHN), naphthalene (NAP), phenanthrene (PHE), and pyrene (PYR) by polyvinyl chloride microplastics (PVC-MPs). Based on the phenomenological mathematical models, the rate-limiting step for analyte adsorption onto PVC-MPs was adsorption onto active sites (R2 = 0.865-0.995). Except for PHE, analyte adsorption isotherms were well described by the Freundlich model (R2 = 0.992-0.998), and adsorption thermodynamics showed that analyte adsorption on PVC-MPs was a spontaneous exothermic process (ΔH0 < 0; ΔG0 < 0). Based on the order of adsorption efficiency of 2-OHN < NAP < PHE < PYR, which is identical to the competitive adsorption experiment, polycyclic aromatic hydrocarbon (PAH) adsorption on PVC-MPs increased as the aromatic ring number increased and the hydroxyl content decreased. The release of 2-OHN (49 %-52 %) from PVC-MPs into the simulated gastrointestinal environment was greater than that of NAP (5.5 %-5.7 %). Theoretical calculations and adsorption tests indicated that hydrophobic interaction was the primary influence on the adsorption of PAHs and their hydroxylated derivatives by PVC-MPs. These findings improve our understanding of MPs' behavior and dangers as pollutant carriers in the aquatic environment and help us develop recommendations for the pollution control of MPs.

[Meta-analysis of Simotang Oral Liquid in treatment of functional dyspepsia in adults].

This study was conducted to evaluate the efficacy and safety of Simotang Oral Liquid in the treatment of functional dyspepsia in adults. "Simotang Oral Liquid" "Simotang" "Si Mo Tang" "Si Mo Tang Oral Liquid" were used for retrieval of the relevant papers from CNKI, Wanfang, VIP, SinoMed, PubMed, Cochrane Library, Springer Link, and Web of Science from database inception to June 2021. Randomized controlled trial(RCT) of Simotang Oral Liquid in the treatment of functional dyspepsia in adults was screened out for Meta-analysis which was conducted in RevMan 5.3. A total of 16 RCTs were included. Meta-analysis showed that compared with the control group, Simotang Oral Liquid increased the total response rate and lowered the traditional Chinese medicine syndrome scores, serum cholecystokinin(CCK), serum nitric oxide(NO), and incidence of adverse reactions. However, the serum substance P(SP) had no statistical difference between the two groups. Simotang Oral Liquid is effective and safe in the treatment of functional dyspepsia in adults. However, this study has evidence and limitations, so the conclusions need to be further verified by large sample and multicenter clinical studies.

Azole-Induced Color Vision Deficiency Associated with Thyroid Hormone Signaling: An Integrated In Vivo, In Vitro, and In Silico Study.

Azoles that are used in pesticides, pharmaceuticals, and personal care products can have toxic effects on fish. However, there is no information regarding azole-induced visual disorder associated with thyroid disruption. We evaluated changes in retinal morphology, optokinetic response, transcript abundance of the genes involved in color perception and hypothalamic-pituitary-thyroid (HPT) axis, and thyroid hormone (TH) levels in zebrafish larvae exposed to common azoles, such as climbazole (CBZ, 0.1 and 10 µg/L) and triadimefon (TDF, 50 and 500 µg/L), at environmentally relevant and predicted worst-case environmental concentrations. Subsequently, the effect of azoles on TH-dependent GH3 cell proliferation and thyroid receptor (TR)-regulated transcriptional activity, as well as the in silico binding affinity between azoles and TR isoforms, was investigated. Azole exposure decreased cell densities of the ganglion cell layer, inner nuclear layer, and photoreceptor layer. Zebrafish larvae exposed to environmentally relevant concentrations of CBZ and TDF showed a decrease in optokinetic response to green-white and red-white stripes but not blue-white stripes, consistent with disturbance in the corresponding opsin gene expression. Azole exposure also reduced triiodothyronine levels and concomitantly increased HPT-related gene expression. Molecular docking analysis combined with in vitro TR-mediated transactivation and dual-luciferase reporter assays demonstrated that CBZ and TDF exhibited TR antagonism. These results are comparable to those obtained from a known TR antagonist, namely, TR antagonist 1, as a positive control. Therefore, damage to specific color perception by azoles appears to result from lowered TH signaling, indicating the potential threat of environmental TH disruptors to the visual function of fish.

Sinuhirtone A, An Uncommon 17,19-Dinorxeniaphyllanoid, and Nine Related New Terpenoids from the Hainan Soft Coral Sinularia hirta.

Chemical investigation of the Hainan soft coral Sinularia hirta resulted in the isolation and identification of a library of sixteen structurally diverse terpenoids, including a dinorditerpenoid with an uncommon 17,19-dinorxeniaphyllane skeleton, namely sinuhirtone A (7), six new xeniaphyllane-type diterpenoids (1-6), one new norxeniaphyllanoid (8), two new norcaryophyllene-type sesquiterpenoids (9 and 10), together with six known related compounds (11-16). Compounds 1-3 are three new furanone-containing xeniaphyllane-type diterpenoids. The structures of the new compounds, including their absolute configurations, were determined by extensive spectroscopic analysis and a series of quantum chemical calculations, including quantum mechanical-nuclear magnetic resonance (QM-NMR), time-dependent density functional theory-electronic circular dichroism (TDDFT-ECD), and optical rotatory dispersion (ORD) methods. A plausible biosynthetic connection between new compounds 1-9 was also proposed. New compounds 2-4, 7, and 8 were evaluated for in vitro cytotoxicity against four cancer cell lines.

Precise surface control of cathode materials for stable lithium-ion batteries.

The increasing demand for high-energy Li-ion batteries (LIBs) continues to push the development of electrode materials, particularly cathode materials, towards their capacity limits. Despite the enormous success, the stability and reliability of LIBs are becoming a serious concern due to the much-aggravated side reactions between electrode materials and organic electrolytes. How to stabilize the cathode/electrolyte interface is therefore an imperative and urgent task drawing considerable attention from both academia and industry. An active treatment on the surface of cathode materials, usually by introducing an inert protection layer, to diminish their side reaction with electrolytes turns out to be a reasonable and effective strategy. This Feature Article firstly outlines our synthesis efforts for the construction of a uniform surface nanocoating on various cathode materials. Different wet chemical routes have been designed to facilitate the control of growth kinetics of targeted coating species so that a precise surface coating could be achieved with nanometer accuracy. Furthermore, we showed the possibility to transform the outer coating layer into a surface doping effect through surface solid reaction at high temperature. A detailed discussion on the structure-performance relationship of these surface-controlled cathode materials is introduced to probe the stabilization mechanism. Finally, perspectives on the development tendency of high-energy cathodes for stable LIBs are provided.

Role of Astaxanthin as a Stimulator of Ovarian Development in Nile Tilapia (Oreochromis niloticus) and Its Potential Regulatory Mechanism: Ameliorating Oxidative Stress and Apoptosis.

A 60-day feeding experiment was performed to evaluate the effect of dietary astaxanthin on gonad development, the antioxidant system, and its inherent mechanism in female Nile tilapia (Oreochromis niloticus). Fish were fed with diets containing astaxanthin at five levels [0 mg/kg (control), 50 mg/kg, 100 mg/kg, 150 mg/kg, and 200 mg/kg]. At the end of experiment, the group fed with 150 mg/kg astaxanthin showed significantly increased specific growth rate, feed utilization, viscerosomatic index, and hepatosomatic index compared with the control group (P < 0.05). Gonad development was stimulated in the groups fed with 100 mg/kg and 150 mg/kg astaxanthin, and their gonadosomatic index and egg diameter were significantly higher than those of the control group and the group fed with 200 mg/kg astaxanthin. The ovaries of females in the groups fed with 100 mg/kg and 150 mg/kg astaxanthin were fully developed, the eggs were gray-yellow and uniform in size, and a large number of oocytes developed to stages IV and V. The serum levels of 17 ß-estradiol, follicle-stimulating hormone, and luteinizing hormone were significantly higher in the groups fed with 100 mg/kg and 150 mg/kg astaxanthin than in the group fed with 200 mg/kg astaxanthin. Compared with the control and the other groups, the group fed with 150 mg/kg astaxanthin showed significantly higher transcript levels of genes encoding hormone receptors and higher catalase activity in ovarian tissues, lower malondialdehyde content, decreased apoptosis (reduced granulosa cell apoptosis and lower transcript levels of bax and caspase-3), and reduced follicular atresia. Gene ontology analyses revealed that cell division and the cell cycle were enriched with differentially expressed genes in the group fed with 150 mg/kg astaxanthin, compared with the control group. We concluded that dietary astaxanthin at a concentration of 150 mg/kg activates follicle development by inhibiting expression of mapk1 (involved in MAPK signaling) and increasing the expression genes involved in oocyte meiosis (chp2, ppp3ca, map2k1, and smc1a1) and progesterone-mediated oocyte maturation (igf1, plk1, and cdk1). In conclusion, female Nile tilapia fed with 150 mg/kg astaxanthin showed increased growth, reduced oxidative stress in ovarian tissue, lower levels of cell apoptosis, and improved oocyte development.

Effects of hydroxyl group content on adsorption and desorption of anthracene and anthrol by polyvinyl chloride microplastics.

Pollutant-attached microplastics have received increasing attention in recent years. However, information regarding the influence of hydroxyl group content of pollutants on the adsorption and desorption behavior is unclear, which affects their fate and risks in the aquatic environment. In this study, we investigated the adsorption and desorption behavior of anthracene (ANT) and its hydroxy derivatives (OHAs), including 2-hydroxyanthracene (MOHA), 2,6-dihydroxyanthracene (DOHA), and 1,8,9-trihydroxyanthracene (TOHA) on polyvinyl chloride (PVC) microplastics, and their interaction mechanism through the batch, characterization, and computational experiments. The results showed that the adsorption of ANT and OHAs on PVC microplastics conformed to the pseudo-second-order kinetic model and was exothermic spontaneously. The adsorption efficiency on PVC followed the order of ANT > MOHA > DOHA > TOHA, indicating that increase in hydroxyl group substitution degree will inhibit pollutant adsorption on PVC microplastics. Conversely, the release amounts of MOHA from PVC into simulated gastric fluids were higher than those of ANT. Experimental and computational results suggested that the affinity of ANT/OHAs to PVC microplastics was the most likely outcome in hydrophobic effect, electrostatic repulsion, and CH-π interaction forces. These findings help elucidate the mechanisms of pollutant adsorption on microplastics and evaluate the risk of pollutant-attached microplastics in the aquatic environment.

[Meta-analysis of efficacy and safety of Shexiang Tongxin Dripping Pills combined with conventional therapy of coronary heart disease].

The aim of the research was to evaluate the efficacy and safety associated with Shexiang Tongxin Dropping Pills combined with conventional therapy for patients with coronary heart disease(CHD). We searched 8 electronic databases up to November 2020, including PubMed, Cochrane Library, EMbase, Web of Science, CNKI, Wanfang, VIP and SinoMed. Eligible studies were clinical trials of Shexiang Tongxin Dropping Pills combined with conventional therapy used in the treatment of coronary heart disease(CHD). The Meta-analysis was performed using STATA 15 software. A total of 21 RCTs(n=2 186) were shortlisted for the Meta-analysis. The results of efficacy evaluation showed that the total effective rate of Shexiang Tongxin Dropping Pills combined with conventional therapy was higher than that of conventional therapy of coronary heart disease(RR=1.20, 95%CI[1.15, 1.26], Z=8.63, P<0.001). Furthermore, Shexiang Tongxin Dripping Pills combined with conventional therapy had better effect on electrocardiogram efficacy(RR=1.24, 95%CI[1.16, 1.34], Z=5.98, P<0.001) and the number of angina attacks(SMD=-2.30, 95%CI[-3.47,-1.14], Z=3.88, P<0.001), the duration of angina attack(SMD=-2.31, 95%CI[-3.07,-1.55], Z=5.97, P<0.001), with lower levels of LDL-C(SMD=-0.73, 95%CI[-1.32,-0.14], Z=2.42, P=0.016), TC(SMD=-1.16, 95%CI[-1.35,-0.96], Z=11.56, P<0.001) and TG(SMD=-0.87, 95%CI[-1.06,-0.68], Z=8.97, P<0.001), and higher levels of HDL-C(SMD=0.87, 95%CI[0.02, 1.71], Z=2.00, P=0.045). The results of safety evaluation showed that the incidence of adverse reactions of Shexiang Tongxin Dropping Pills combined with conventional therapy was lower than that of conventional therapy of coronary heart disease(RR=0.45, 95%CI[0.22, 0.91], Z=2.23, P=0.026). There were significant differences in the above outcome indexes between the two groups. After the Harbord method test, the total effective rate outcome index has publication bias, but the sensitivity analysis of the cut-and-fill method suggested that the result was stable. In general, limited by the quantity and quality of included literature, more high-quality studies are needed to further verify the conclusions of this study.

[Pharmacoeconomic evaluation of Shexiang Tongxin Dropping Pills combined with conventional Western medicine treatment for coronary heart disease by Markov model].

This research was to evaluate the economics of Shexiang Tongxin Dropping Pills combined with conventional therapy for patients with coronary heart disease(CHD) in Chinese medical environment. From the perspective of medical insurance, a Markov model was established in this study based on the results of Meta-analysis comparing the effectiveness and safety of Shexiang Tongxin Dripping Pills combined with conventional treatment and conventional treatment alone. The experimental group was treated with She-xiang Tongxin Dropping Pills combined with conventional Western medicine treatment, while the control group was treated with conventional Western medicine treatment alone. The cost-utility analysis and sensitivity analysis were performed for the two regimens using Treeage pro. After 30 cycles of model simulation, according to the results of Markov model, the total cost and health output were CNY 237 795.73 and 16.36 QALYs(the quality adjusted life years, QALYs), respectively for Shexiang Tongxin Dropping Pills combined with conventional Western medicine treatment, CNY 247 396.55 and 16.36 QALYs respectively for the conventional Western medicine treatment alone. Compared with the conventional treatment alone, the Shexiang Tongxin Dropping Pills combined with conventional treatment had lower long-term cost and higher health output, with advantages of cost-utility and pharmacoeconomic advantages. The sensitivity analysis results showed that the conclusion was relatively stable. Based on the above results, it is considered that compared with the conventional Western medicine alone, Shexiang Tongxin Dropping Pill combined with conventional Western medicine is a treatment regimen with pharmacoeconomic advantages for the treatment of CHD.

The obesity indices mediate the relationships of blood lipids and bone mineral density in Chinese elders.

OBJECTIVE: It is unclear what role does obesity (OB) index play between blood lipid and bone mineral density (BMD). SUBJECTS: This study recruited a total of 4,558 Chinese elders >65 years. OB indices: waist circumference (WC), body mass index (BMI), waist-hip-ratio (WHR); blood lipid parameters: low density lipoprotein (LDL); total cholesterol (TC), triglyceride (TG), and BMDs at femur neck (FN), total hip (TH), and lumbar spine (LS) were measured. The t-test and multiple linear regression analysis were used to detect the differences of variables. Casual inference test (CIT) were performed to test potential mediators underlying the associations between blood lipid and BMD. RESULTS: The blood lipids were positively associated with BMD (p < 0.05) after adjustment of age and sex (Model 1) both in total subjects and in sex-stratified subjects. The CIT showed that OB indices had significant mediation effects on the associations between blood lipid (TG and LDL) and BMD in total subjects and males. Comparably, the correlations of TG and BMD are most likely mediated by BMI and WC. CONCLUSIONS: This study represented the first effort to report that OB indices, especially BMI and WC, served as significant mediators between blood lipid (TG and LDL) and BMD in Chinese elderly.

Newly developed hip geometry parameters are associated with hip fracture.

BACKGROUND: The conventional and newly developed geometry parameters at the femoral neck have formed a large geometry profile and their relationship with hip fracture was largely unknown. We aimed to evaluate the relationship between the geometry profile and hip fracture in Chinese. METHODS: The hip geometry profile contains seven conventional geometry parameters at femoral neck (FN) and thirty newly developed parameters at three sub-regions (Narrow Neck, NN; Intertrochanter, IT; Femoral shaft, FS) of the total hip. Based on 6294 recruited Chinese (≥65 years), 97 subjects with osteoporotic fracture (OF) history and 388 matched controls were selected. The t test, Chi-square statistic, conditional logistic regression model were used. RESULTS: Three geometric parameters (endocortical diameter, ED; cortical thickness, CT; buckling ratio, BR) have consistent differences at all the sites between the cases and controls (p < 0.01). Conventional geometry parameters (e.g., cross-sectional area, CSA; BR) and the newly developed parameters (e.g., NN_ED, NN_Outer Diameter, IT_ED) were identified as the risk factors of hip fracture independent of BMD. The additional predictive ability of the hip geometric parameters, over BMD alone, (receiver operating characteristic curve (ROC) analysis) was improved. Especially at NN, the area of ROC used single NN_BMD is only 0.596, but increased rapidly at 0.705 when combined with the hip geometric parameters. CONCLUSIONS: This study found that three newly developed hip geometry parameters are associated with hip fracture. The results will increase our understanding of the determinants of fracture and provide potential clue for future prevention of fracture in Chinese Population.

Long-Distance Chirality Transfer from P-Ligand to Prochiral Dihydrosilanes via Pd(II) Aryl Iodide Complex in Pd-Catalyzed Silylation of Aryl Iodide: A DFT Study.

The mechanism of Pd-catalyzed desymmetric monoarylation of dihydrosilanes with aryl iodides in the presence of chiral TADDOL-derived phosphoramidite ligand toward deeper understanding of the stereoselectivity has been investigated using hybrid density functional theory (DFT) methodology. The full catalytic cycle for the favorable reaction pathway, which is initiated by the oxidative addition of aryl iodide to monoligated Pd0 leading to the silylation product, was calculated. The DFT calculation results indicate that the enantio-discriminating transmetalation between Pd-Ar bond of the Pd(II) aryl iodide complex and Si-H bond of the prochiral dihydrosilane was the enantioselectivity-determining step. On the basis of the structure of the transition state, the attractive aryl-aryl interactions between the aryl group of ligand, aryl iodide, and dihydrosilane were found to play an important role for the chiral transference from the chiral ligand to asymmetric cleavage of the Si-H bond of the prochiral dihydrosilane.

A Chiral Thermochromic Ferroelastic with Seven Physical Channel Switches.

Switchable materials play an invaluable role in signal processing and encryption of smart devices. The development of multifunctional materials that exhibit switching characteristics in multiple physical channels has attracted widespread attention. Now, two chiral thermochromic ferroelastic crystals (S-CTA)2 CuCl4 and (R-CTA)2 CuCl4 (CTA=3-chloro-2-hydroxypropyltrimethylammonium) have been prepared with switchable properties in dielectricity, conductivity, second harmonic generation (SHG), piezoelectricity, ferroelasticity, chiral, and thermochromic properties. Compared with traditional phase-transition materials with switching features, thermochromism brings additional spectral encryption possibilities for future information processing. To the best of our knowledge, this is the first chiral thermochromic ferroelastic that exhibits switching properties in seven physical channels. This work is expected to promote further exploration of multifunctional molecular switchable materials.

Stereo- and regio-selective synthesis of silicon-containing diborylalkenes via platinum-catalyzed mono-lateral diboration of dialkynylsilanes.

A highly chemoselective platinum-catalyzed mono-lateral diboration of dialkynylsilanes for the construction of silicon-tethered alkynyl diborylalkenes is described, in which tris(4-methoxyphenyl)phosphine was found to be an effective ligand for the cis-addition of diboron agents to the silicon-tethered alkynes, and the chiral ligand (AFSi-Phos)-mediated diboration of dialkynylsilanes resulted in the desymmetric construction of silicon-stereogenic centers with promising enantioselectivity.

A Three-Dimensional M3 AB-Type Hybrid Organic-Inorganic Antiperovskite Ferroelectric: [C3 H7 FN]3 [SnCl6 ]Cl.

Since the first perovskite CaTiO3 was discovered in 1839, the development of perovskite has a history of 180 years. The emergence of solar cells (CH3 NH3 )PbI3 has set off the trend of hybrid organic-inorganic perovskite (HOIP) materials. Since then, various HOIPs have sprung up and been widely used in various material devices. Among them, HOIP ferroelectrics have gained widespread attention. However, antiperovskite, as a twin brother of perovskite, has been neglected although it has similar structure with perovskite. Here, we successfully found that [C3 H7 FN]3 [SnCl6 ]Cl has a three-dimensional (3D) antiperovskite structure with the formula M3 AB. Importantly, the compound exhibits obvious ferroelectric properties with an Aizu notation of 622F6 at 391 K. To the best of our knowledge, this is the first 3D hybrid organic-inorganic antiperovskite ferroelectric, which will greatly promote the development of antiperovskite families with more superior physical properties.

Two-Dimensional Organic-Inorganic Perovskite Ferroelectric Semiconductors with Fluorinated Aromatic Spacers.

Two-dimensional (2D) organic-inorganic perovskites (OIPs), with improved material stability over their 3D counterparts, are highly desirable for device applications. It is their considerable structural diversity that offers an unprecedented opportunity to engineer materials with fine-tuning functionalities. The isosteric substitution of hydrogen by an electronegative fluorine atom has been proposed as a useful route to improve the photovoltaic performance of 2D OIPs, whereas its valuable role in developing ferroelectricity is still waiting for further exploration. Herein, for the first time we applied fluorinated aromatic cations in extending the family of 2D OIP ferroelectrics, and successfully obtained [2-fluorobenzylammonium]2PbCl4 as a high-performance ferroelectric semiconductor. The failures in the nonferroelectric [4-fluorobenzylammonium]2PbCl4 and [3-fluorobenzylammonium]2PbCl4 demonstrate that the selective introduction of fluorine in correct structural positions is particularly essential. This work represents an unprecedented proof-of-concept in the use of fluorinated aromatic cations for the targeted design of excellent 2D OIP ferroelectrics, and is believed to inspire the future development of low-cost, high-efficiency, and stable device applications.