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ABSTRACT The bioaccumulation and excretion of enantiomers of myclobutanil in Tenebrio molitor larvae through dietary exposure under laboratory conditions were investigated using high-performance tandem (HPLC-MS/MS) based on a ChiralcelOD-3R [cellulosetris- tris-(3, 5-dichlorophenyl-carbamate)] column. The wheat bran fed to Tenebrio molitor larvae was spiked with racemic myclobutanil at two dose levels of 20 mg/kg and 2 mg/kg (dry weight). The results showed that there was a significant trend of bioaccumulation in the larvae with a preferential accumulation of (−)-myclobutanil in 20 mg/kg dose exposure, but it was not obviously observed in the 2 mg/kg dose group. A kinetic model considering enantiomerization between the two enantiomers based on first-order reactions was built and the rate constants were estimated to discuss the kinetic reason for the different concentrations of individual enantiomers in the larvae. The approximations implied an between the two enantiomers with a relatively higher rate of the from (−)-myclobutanil to (+)-myclobutanil. Meanwhile, analysis of data of excretion samples suggested the active excretion is probably an important pathway for the insect to eliminate myclobutanil rapidly with nonenantioselectivity as a passive transport process, which was consistent with the low accumulation efficiency of myclobutanil measured by BAF (bioaccumulation factor). Chirality 25:890-896, 2013. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Highlights: [•] Surface fluorinated TiO2 (F–TiO2) had the remarkable activity for PCO of NH3. [•] Surface fluorination formed the surface Ti–F group. [•] Surface fluorination increased the reactive (001) facets percentage to about 50%. [•] Both Ti–F group and reactive (001) facets led to the high activity of F–TiO2. [•] Surface Ti–F group plays the dominant role in enhancing the PCO of NH3 activity. [Copyright &y& Elsevier]

Crystal facet engineering is an effective strategy for designing efficient catalysts to improve the ability to oxidize formaldehyde (HCHO). In this article, anatase TiO2 samples with different main exposed crystal facets ((001), (010) and (101)) were prepared and utilized as supports to load Pd, leading to the synthesis of Pd/TiO2 (001), Pd/TiO2 (010) and Pd/TiO2 (101) catalysts, respectively. For HCHO oxidation, Pd/TiO2 (001) displayed the best activity, and could convert 100% HCHO at 35 °C. However, the removal rates for Pd/TiO2 (010) and Pd/TiO2 (101) catalysts were only 46% and 35% even at 55 °C. After carefully comparing the property differences of these three supports, it was found that more surface defects were formed on the (001) facet than on (010) and (101). With more surface defects of support, Pd/TiO2 (001) catalyst possessed more oxygen vacancies, Pd metal sites and interface sites, which could effectively activate oxygen and water. This further improved the ability to oxidize HCHO. The findings from this study are anticipated to contribute valuable insights for the design of highly efficient supported noble metal catalysts.Graphical Abstract: Crystal facet engineering is an effective strategy for designing efficient catalysts to improve the ability to oxidize formaldehyde (HCHO). In this article, anatase TiO2 samples with different main exposed crystal facets ((001), (010) and (101)) were prepared and utilized as supports to load Pd, leading to the synthesis of Pd/TiO2 (001), Pd/TiO2 (010) and Pd/TiO2 (101) catalysts, respectively. For HCHO oxidation, Pd/TiO2 (001) displayed the best activity, and could convert 100% HCHO at 35 °C. However, the removal rates for Pd/TiO2 (010) and Pd/TiO2 (101) catalysts were only 46% and 35% even at 55 °C. After carefully comparing the property differences of these three supports, it was found that more surface defects were formed on the (001) facet than on (010) and (101). With more surface defects of support, Pd/TiO2 (001) catalyst possessed more oxygen vacancies, Pd metal sites and interface sites, which could effectively activate oxygen and water. This further improved the ability to oxidize HCHO. The findings from this study are anticipated to contribute valuable insights for the design of highly efficient supported noble metal catalysts. [ABSTRACT FROM AUTHOR]

Organic–inorganic hybrid materials, which exhibit structural diversity and rich physical properties, have shown great potential as basic device elements in the optoelectronic field. Herein, we report a new lead-free organic–inorganic hybrid compound, [C3H8N]2SbBr5 (1, where C3H8N+ is the cyclopropylammonium cation), which demonstrates tunable dielectric responses near room temperature, derived from its two successive structural phase transitions at the vicinity of T1 = 290 K and T2 = 315 K, respectively. That is, its dielectric constants change from high-dielectric (above T2), moderate-dielectric (between T2 and T1) and low-dielectric states (below T1). Such dielectric behaviors coincide well with a series of reversible thermal peaks in the DSC curve. Further structural analyses reveal that the order–disorder of organic cationic moieties accounts for the phase transition at T2, while the change of the molecular configuration provides the driving force to the phase transition at T1. Such phase transition behaviours differ from those of the majority of previously reported dielectric phase transition materials. Moreover, theoretical calculation of the electronic band structure of 1 reveals the direct feature with a band-gap value of ∼2.36 eV. This work affords broader design flexibility for the future exploration of electrically-ordered materials in the organic–inorganic hybrid family. [ABSTRACT FROM AUTHOR]

As our previous works found, alkali metals have a common promotion effect on supported noble metals catalysts for formaldehyde (HCHO) oxidation. As second-group elements, alkaline earth metals (AEMs) are neighbors to the first-group elements and share some properties in common. However, detailed investigations into the specific mechanisms underlying AEMs' effects on HCHO oxidation remain limited. In this study, we found that Ba addition showed a similar promotion effect on HCHO oxidation for Pd/TiO 2 . Ba species stabilized Pd groups, improved the dispersion, and even caused a large number of monatomic-like Pd sites to appear, which may be attributed to the electronic interaction between promoter and metal (EIPM) between Ba and Pd. Besides, AEM loading had the important effect of increasing the electron density of metallic Pd nanoparticles, which further improved the ability for O 2 activation and so enhanced the mobility of chemisorbed oxygen on the catalyst surface. For Pd/TiO 2 , the HCHO oxidation path is mainly HCHO→HCOOH→HCOO→H 2 O+CO 2 . By contrast, for Pd-Ba/TiO 2 , with more surface-active species, the formate intermediate was more likely to be directly oxidized into H 2 O and CO 2 , which is a more effective reaction pathway. The details of the EIPM between Pd and Ba were investigated by GPAW (DFT calculation module) in ASE (Atomic Simulation Environment). The AEM Ba acted as an electron donor and could interact with Pd d orbital electrons through BaO sp orbital electrons. Ba species were highly dispersed on the carrier due to the Ba-Ti interaction. Ba species dispersed over large areas stabilized the Pd particles and donated electrons to Pd. Therefore, adding an AEM is an efficacious strategy to improve the performance of the catalytic oxidation of HCHO., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Polarized-light photodetectors are the indispensable elements for practical optical and optoelectronic device applications. Two-dimensional (2D) hybrid perovskite ferroelectrics, in which the coupling of spontaneous polarization (P s ) and light favors the dissociation of photo-induced carriers, have taken a booming position within this portfolio. However, polarized-light photodetectors with a low detection-limit remain unexplored in this 2D ferroelectric family. In this work, the high-quality individual crystals of a 2D perovskite ferroelectric, BA 2 CsPb 2 Br 7 (1, where BA + is n-butylammonium), were used to fabricate ultrasensitive polarized-light detectors. Its unique bilayered structural motif results in quite strong electric and optical anisotropy with a large absorption ratio of α c /α a ≈ 3.2 (λ = 405 nm). Besides, the presence of ferroelectric P s also endows high built-in electric field along the polar c-axis that favors photoelectric activities. Under an extremely low detectable limit of 40 nW/cm 2 , the detector of 1 exhibits a notable dichroism ratio (I ph c /I ph a ≈ 1.5), a large responsivity of ~39.5 mA/W and a specific detectivity of ~1.2 × 10 12 Jones. Moreover, crystal-based devices of 1 also exhibit a fast response speed (~300 μs) and excellent anti-fatigue merits. This work highlights great potentials of hybrid perovskite ferroelectrics toward polarized-light photodetection., Competing Interests: Conflict of interest The authors declare that they have no conflict of interest., (Copyright © 2020 Science China Press. Published by Elsevier B.V. All rights reserved.)

Perovskite hybrids of lead organometal halides, (e. g., CH 3 NH 3 PbX 3 , X=Cl, Br, I) have gained wide attention since their spectacular progress on optoelectronic technologies in recent years. However, it still remains the fundamental problem, namely, the existence of the toxic, bioaccumulative, polluting element Pb and the instability of humidity. In particular, the use of toxic Pb severely limits the broad applications and commercialization of lead-containing optoelectronic devices, and finding an alternative that preserves the unique optoelectronic properties of the lead halide perovskite is highly urgent. Bi 3+ exhibits isoelectronic behavior similar to that of Pb 2+ in terms of ion radius and electronegativity, which is expected as an environmentally friendly alternative for lead. However, 1D Bi-based hybrid organic-inorganic light-absorbing materials with pyridinium are not numerous. Although great progress has been made, the research on photoresponse behavior are still rarely reported. Here, we present a lead-free organic-inorganic hybrid absorber with photoconductive response, (C 5 H 7 N 2 )BiI 4 (1, C 5 H 7 N 2 + is 2-aminopyridinium), which displays a narrow optical bandgap of ∼1.8 eV. Equally importantly, 1 not only features highly applicable properties, but is also able to absorb across most of the UV/Vis region of the solar spectrum. Furthermore, high-quality single crystal with sizes up to 7×6×4 mm 3 was successfully grown. In addition, 1 exhibited extremely low dark current (2×10 -11  A) at the bias of 10 V, which indicates that the indicator of 1 is an order of magnitude lower than other reported perovskite photodetectors. Moreover, photocurrent on/off switches is faster (∼670 ms), indicating that 1 can be a promising photosensitive switch. These intriguing properties, namely the lead-free composition, a small band gap, and the fast photoconductive response, suggest promising applications in the field of optoelectronics., (© 2020 Wiley-VCH GmbH.)

Study Design: Retrospective observational cohort study., Objectives: To compare the benefits of long and short fusion treatments, and to identify factors potentially aiding surgeons' decision making about the surgical management of degenerative lumbar scoliosis associated with spinal stenosis (DLSS)., Summary of Background Data: The comparative effectiveness of long and short segment fusion for the treatment of DLSS remains controversial., Methods: Fifty-three patients with symptomatic DLSS managed by posterior-only fusion surgery were enrolled in this study. Twenty patients underwent short fusion (fewer than two segments), and 33 patients had more than three segments fused. The radiological outcomes were assessed by radiography. Health-related quality of life data, including visual analog scale (VAS) and Oswestry Disability Index (ODI) scores, were collected at all preoperative and follow-up visits., Results: The short and long fusion groups showed significant differences in the change in the Cobb angle (4.2° vs. 11.2°), lumbar lordosis (3.9° vs. 11.5°), and pelvic incidence minus the lumbar lordosis angle (PI - LL; 3.2° vs. 11.2°). Both the short and long fusion achieved significant changes in low back pain and leg pain. Patients with PI -LLs > 10° had more relief of low back pain after long fusion (VAS 4.0 ± 2.0) than after short fusion (VAS 2.6 ± 1.7). Patients with PI - LLs > 10° showed significantly improved walking ability after long fusion (ODI 1.0 ± 0.8). The improvement in standing ability after short fusion was greater when PI - LL ≤ 10°(ODI 0.9 ± 0.6)., Conclusion: Long segment fusion can relieve low back pain better and improve walking ability when PI-LL is mismatched, whereas short segment fusion is more advantageous in improving standing ability in cases of more balanced sagittal spinopelvic alignment., Level of Evidence: 3.

Objective: To analyze the risks of the distal adding-on phenomenon and identify the ideal lowest instrumented vertebra (LIV) for Lenke IA and IIA., Methods: A total of 84 patients with Lenke IA or Lenke IIA treated with posterior all-pedicle-screw instrumentation were enrolled in this cohort study. Radiographs that were obtained before, immediately after, and 2 years after the operation were measured. Patients were grouped based on the occurrence of the adding-on phenomenon. Independent risk factors were evaluated between these 2 groups via univariate analysis and logistic regression analysis., Results: All patients obtained optimal correction of the main thoracic curve and lumbar curve after selective thoracic fusion. Eighteen patients among a total of 84 patients suffered from the distal adding-on phenomenon during the 2-year follow-up. Multivariable analysis revealed that the primary factors were preoperative thoracolumbar or lumbar curve size in supine side-bending films (odds ratio 0.75, P = 0.008), preoperative thoracic kyphosis (T5-T12) (odds ratio 0.743, P = 0.022), and the difference between the LIV and the LSTV (lowest substantial touched vertebra). All 7 (100%) patients whose LIVs were proximal to the LSTV suffered from distal adding-on phenomenon, whereas 7 of 40 (17.5%) suffered from distal adding-on phenomenon when the LIV was distal to the LSTV. Patients whose LIV was distal to the LSTV had the lowest incidence of the distal adding-on phenomenon (10.8%)., Conclusions: An LIV located proximal to the LSTV should be avoided during selective thoracic fusion for Lenke IA and IIA to prevent the distal adding-on phenomenon. For patients who have a small thoracolumbar or lumbar curve size in bending films or a small T5-T12 angle before surgery, the next vertebra distal to the LSTV may be an optimal choice., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Lead (Pb) is a widespread environmental heavy metal toxicant and chronic Pb exposure can have irreversible effects on memory and cognitive function, which is closely related to dendritic spines. Studies have shown that SNX6 and Homer1 can regulate the growth of dendritic spines. We aimed to investigate the effect of Pb exposure on the dendritic spines in hippocampus, the expression of SNX6 and Homer1 in rats and PC12 cells. The animals were randomly divided to three groups: control group, low lead group and high lead group. PC12 cells were divided into 3 groups: 0 μM, 1 μM and 100 μM Pb acetate. The results showed that the Pb levels in blood and hippocampus of all exposure groups were significantly higher than that of the control group. The morphology of dendritic spines in hippocampus after Pb treatment was changed and the density of dendritic spines was reduced. The expression of SNX6 and Homer1 was decreased in Pb exposed groups compared with the control group. Furthermore, up-regulation of SNX6 expression could reverse the down-regulation of Pb exposure on Homer1. These results indicate that Pb exposure can reduce the expression of SNX6 and lead to a decrease in Homer1 expression, which affects the changes in dendritic spines causing learning and memory impairment., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Lead (Pb) is an environmental neurotoxic metal. Chronic exposure to Pb causes deficits of learning and memory in children and spatial learning deficits in developing rats. In this study we investigated the effects of Pb exposure on the expression of HMGB1 and HO-1 in rats and PC12 cells. The animals were randomly divided to three groups: control group; low lead exposure group; high lead exposure group; PC12 cells were divided into 3 groups: 0 μM (control group), 1 μM and 100 μM Pb acetate. The results showed that Pb levels in blood and brain of Pb exposed groups were significantly higher than that of the control group (p < 0.05). The expression of HMGB1 and HO-1 were increased in Pb exposed groups than that of the control group (p < 0.05). Moreover, we found that the up-regulation of HO-1 in Pb exposure environment inhibited the expression of HMGB1., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Lead (Pb) exposure has been shown to affect presynaptic neurotransmitter release in the animal and cell models. The mechanism by which Pb exposure impairs neurotransmitter release remains unknown. In this study, we aimed to investigate the effect of Pb exposure on synaptic vesicle protein 2C (SV2C) and its molecular mechanism. SV2C promoter region contains a neuron-restrictive silencer element (NRSE) binding motif. Neuron-restrictive silencer factor (NRSF) is a transcription repressor that regulates gene expression by binding to NRSE. We also observed whether Pb exposure regulates the transcriptional level of SV2C by influencing the expression of NRSF. Pregnant female rats were exposed to 0, 0.5 and 2.0 g/L lead acetate (PbAc) via drinking water from the first day of gestation until postnatal week 3. Neuro-2a (N2a) cells were divided into 3 groups: 0 μM (control group), 1 μM and 100 μM PbAc. Our data revealed that the ability of learning and memory in Pb-exposed rats were decreased, Pb exposure decreased SV2C expression and increased NRSF expression in the rat hippocampus and N2a cell. Silencing NRSF can reverse the down-regulation of Pb exposure on SV2C. These results indicate that Pb exposure can inhibit the transcription level of SV2C by up regulating the expression of NRSF. Decreased expression of SV2C can affect neurotransmitter release and synaptic transmission, which affect synaptic plasticity and then result in impairment of learning and memory., (Copyright © 2018 Elsevier B.V. All rights reserved.)