Solving a new R2lox protein structure by microcrystal electron diffraction

Microcrystal electron diffraction (MicroED) has recently shown potential for structural biology. It enables the study of biomolecules from micrometer-sized 3D crystals that are too small to be studied by conventional x-ray crystallography. However, to date, MicroED has only been applied to redetermine protein structures that had already been solved previously by x-ray diffraction. Here, we present the first new protein structure-an R2lox enzyme-solved using MicroED. The structure was phased by molecular replacement using a search model of 35% sequence identity. The resulting electrostatic scattering potential map at 3.0-Å resolution was of sufficient quality to allow accurate model building and refinement. The dinuclear metal cofactor could be located in the map and was modeled as a heterodinuclear Mn/Fe center based on previous studies. Our results demonstrate that MicroED has the potential to become a widely applicable tool for revealing novel insights into protein structure and function.

Phase Transformation Behavior of a Two-Dimensional Zeolite

Understanding the molecular-level mechanisms of phase transformation in solids is of fundamental interest for functional materials such as zeolites. Two-dimensional (2D) zeolites, when used as shape-selective catalysts, can offer improved access to the catalytically active sites and a shortened diffusion length in comparison with their 3D analogues. However, few materials are known to maintain both their intralayer microporosity and structure during calcination for organic structure-directing agent (SDA) removal. Herein we report that PST-9, a new 2D zeolite which has been synthesized via the multiple inorganic cation approach and fulfills the requirements for true layered zeolites, can be transformed into the small-pore zeolite EU-12 under its crystallization conditions through the single-layer folding process, but not through the traditional dissolution/recrystallization route. We also show that zeolite crystal growth pathway can differ according to the type of organic SDAs employed.

A metal-organic framework for efficient water-based ultra-low-temperature-driven cooling

Efficient use of energy for cooling applications is a very important and challenging field in science. Ultra-low temperature actuated (T_driving < 80 °C) adsorption-driven chillers (ADCs) with water as the cooling agent are one environmentally benign option. The nanoscale metal-organic framework [Al(OH)(C₆H₂O₄S)] denoted CAU-23 was discovered that possess favorable properties, including water adsorption capacity of 0.37 g_H2O/g_sorbent around p/p₀ = 0.3 and cycling stability of at least 5000 cycles. Most importantly the material has a driving temperature down to 60 °C, which allows for the exploitation of yet mostly unused temperature sources and a more efficient use of energy. These exceptional properties are due to its unique crystal structure, which was unequivocally elucidated by single crystal electron diffraction. Monte Carlo simulations were performed to reveal the water adsorption mechanism at the atomic level. With its green synthesis, CAU-23 is an ideal material to realize ultra-low temperature driven ADC devices.

Towards implementing hierarchical porous zeolitic imidazolate frameworks in dye-sensitized solar cells

A one-pot method for encapsulation of dye, which can be applied for dye-sensitized solar cells (DSSCs), and synthesis of hierarchical porous zeolitic imidazolate frameworks (ZIF-8), is reported. The size of the encapsulated dye tunes the mesoporosity and surface area of ZIF-8. The mesopore size, Langmuir surface area and pore volume are 15 nm, 960-1500 m² · g^-1 and 0.36-0.61 cm³ · g^-1, respectively. After encapsulation into ZIF-8, the dyes show longer emission lifetimes (greater than 4-8-fold) as compared to the corresponding non-encapsulated dyes, due to suppression of aggregation, and torsional motions.

Insights into the Exfoliation Process of V2O5·nH2O Nanosheet Formation Using Real-Time 51V NMR

Nanostructured hydrated vanadium oxides (V₂O₅·nH₂O) are actively being researched for applications in energy storage, catalysis, and gas sensors. Recently, a one-step exfoliation technique for fabricating V₂O₅·nH₂O nanosheets in aqueous media was reported; however, the underlying mechanism of exfoliation has been challenging to study. Herein, we followed the synthesis of V₂O₅·nH₂O nanosheets from the V₂O₅ and VO₂ precursors in real time using solution- and solid-state ⁵¹V NMR. Solution-state ⁵¹V NMR showed that the aqueous solution contained mostly the decavanadate anion [H₂V₁₀O₂₈]^4- and the hydrated dioxovanadate cation [VO₂·4H₂O]⁺, and during the exfoliation process, decavanadate was formed, while the amount of [VO₂·4H₂O]⁺ remained constant. The conversion of the solid precursor V₂O₅, which was monitored with solid-state ⁵¹V NMR, was initiated when VO₂ was in its monoclinic forms. The dried V₂O₅·nH₂O nanosheets were weakly paramagnetic because of a minor content of isolated V⁴⁺. Its solid-state ⁵¹V signal was less than 20% of V₂O₅ and arose from diamagnetic V⁴⁺ or V⁵⁺.This study demonstrates the use of real-time NMR techniques as a powerful analysis tool for the exfoliation of bulk materials into nanosheets. A deeper understanding of this process will pave the way to tailor these important materials.

[Clinical research progress of cell immunity in gastric cancer]

Gastric cancer is the most common gastrointestinal cancer in China. The morbidity and mortality are extremely high and there are significant challenges in the treatment of gastric cancer. Recent studies have shown that the expressions of T lymphocyte subsets vary in the immune microenvironment of gastric cancer patients. T lymphocytes are not only the main effector cells of human cellular immunity, but also the important immunoregulatory cells. T lymphocytes not only reflect the state of the tumor microenvironment, but also closely relate with the prognosis of patients. T lymphocytes play a crucial guiding role in the clinical treatment. Currently, clinical trials related to immunological checkpoint inhibitors are still underway, among which PD-1/PD-L1 monoclonal antibody has been approved for the treatment of gastric cancer. The applications of tumor vaccines and adoptive cell therapies in gastric cancer are also being explored. How to screen patients suitable to immunotherapy, develop the best combination therapy and evaluate the effectiveness of immunotherapy need to be studied and solved.

Phenotypic analysis of atopic dermatitis in children aged 1-12 months: elaboration of novel diagnostic criteria for infants in China and estimation of prevalence

BACKGROUND

Atopic dermatitis (AD) is the most common skin disorder in infancy. However, the diagnosis and definite significance of infantile AD remains a debated issue.

OBJECTIVE

To analyse the phenotypes of AD in infancy, to establish diagnostic criteria and to estimate the prevalence of this condition in China.

METHODS

This is a multicentric study, in which 12 locations were chosen from different metropolitan areas of China. Following careful and complete history-taking and skin examination, the definite diagnosis of AD was made and the severity based on the SCORAD index was determined by local experienced dermatologists. Based on the detailed phenotyping, the major and representative clinical features of infantile AD were selected to establish the diagnostic criteria and evaluate their diagnostic efficacy.

RESULTS

A total of 5967 infants were included in this study. The overall point prevalence of AD was 30.48%. The infantile AD developed as early as at the second month of life, and its incidence peaked in the third month of life at 40.81%. The proportion of mild, moderate and severe AD was 67.40%, 30.57% and 2.03%, respectively. The most commonly seen manifestations in the infantile AD were facial dermatitis (72.07%), xerosis (42.72%) and scalp dermatitis (27.93%). We established the novel diagnostic criteria of infants, which included: (i) onset after 2 weeks of birth; (ii) pruritus and/or irritability and sleeplessness comparable with lesions; and (iii) all two items above with one of the following items can reach a diagnosis of AD: (i) eczematous lesions distributed on cheeks and/or scalp and/or extensor limbs, and (ii) eczematous lesions on any other parts of body accompanied by xerosis.

CONCLUSIONS

In China, the prevalence of AD in infancy is 30.48% according to clinical diagnosis of dermatologists. The novel Chinese diagnostic criteria for AD in infants show a higher sensitivity and comparable specificity.

Analysis of Causes of Death and Related Factors of 102 Perinatal Infants in Chongqing

OBJECTIVES

To analyze the causes of perinatal death and related factors from the perspective of forensic medicine, and to provide references for reducing perinatal mortality and guidance for forensic identification.

METHODS

A retrospective analysis was performed on 102 cases of perinatal autopsy with clinical data from the Department of Forensic Medicine of Chongqing Medical University in 2004-2016.

RESULTS

Of the 102 cases of perinatal deaths, 66 （64.71%） were neonatal deaths, 24 （23.53%） were stillborn foetuses, and 12 （11.76%） were stillbirths. Among the 66 neonatal death cases, 39 （59.09%） died within 1 d, 19 （28.79%） died within 1-3 d, and 8 （12.12%） died within >3-7 d of birth. The top 3 causes of neonatal death were pulmonary diseases, congenital malformation, umbilical cord and placental abnormalities. The causes of stillborn foetus and stillbirth were mainly umbilical cord and placental abnormalities, and intrauterine asphyxia.

CONCLUSIONS

Pulmonary diseases, umbilical cord and placental abnormalities, and congenital malformations are the main causes of perinatal death. In order to reduce the perinatal mortality, pre-pregnancy examination and prenatal care should be strengthened, and the knowledge of pregnancy care should be popularized.

In situ XAS study of the local structure and oxidation state evolution of palladium in a reduced graphene oxide supported Pd(ii) carbene complex during an undirected C–H acetoxylation reaction

In situ XAS is used to reveal the evolution of palladium species during an undirected C–H acetoxylation reaction.

Insights into Functionalization of Metal-Organic Frameworks Using In Situ NMR Spectroscopy

Postsynthetic reactions of metal-organic frameworks (MOFs) are versatile tools for producing functional materials, but the methods of evaluating these reactions are cumbersome and destructive. Here we demonstrate and validate the use of in situ NMR spectroscopy of species in the liquid state to examine solvent-assisted ligand exchange (SALE) and postsynthetic modification (PSM) reactions of metal-organic frameworks. This technique allows functionalization to be monitored over time without decomposing the product for analysis, which simplifies reaction screening. In the case of SALE, both the added ligand and the ligand leaving the framework can be observed. We demonstrate this in situ method by examining SALE and PSM reactions of the robust zirconium MOF UiO-67 as well as SALE with the aluminum MOF DUT-5. In situ NMR spectroscopy provided insights into the reactions studied, and we expect that future studies using this method will permit the examination of a variety of MOF–solute reactions.

High-throughput continuous rotation electron diffraction data acquisition via software automation

Single-crystal electron diffraction (SCED) is emerging as an effective technique to determine and refine the structures of unknown nano-sized crystals. In this work, the implementation of the continuous rotation electron diffraction (cRED) method for high-throughput data collection is described. This is achieved through dedicated software that controls the transmission electron microscope and the camera. Crystal tracking can be performed by defocusing every nth diffraction pattern while the crystal rotates, which addresses the problem of the crystal moving out of view of the selected area aperture during rotation. This has greatly increased the number of successful experiments with larger rotation ranges and turned cRED data collection into a high-throughput method. The experimental parameters are logged, and input files for data processing software are written automatically. This reduces the risk of human error, and makes data collection more reproducible and accessible for novice and irregular users. In addition, it is demonstrated how data from the recently developed serial electron diffraction technique can be used to supplement the cRED data collection by automatic screening for suitable crystals using a deep convolutional neural network that can identify promising crystals through the corresponding diffraction data. The screening routine and cRED data collection are demonstrated using a sample of the zeolite mordenite, and the quality of the cRED data is assessed on the basis of the refined crystal structure.

miRNA-185 regulates retained fetal membranes of cattle by targeting STIM1

Retained fetal membranes (RFM) of cows is an important reproductive disturbance, and is related to miRNA-185. Stromal interaction molecule 1 (STIM1), a potential target gene of miRNA-185, could influence placenta release via regulating Ca²⁺ concentration intracellular. The aim of this study was to explore the mechanism of RFM by investigating the regulatory relationship between miRNA-185 and STIM1 in primary uterine caruncel epithelial (UCE) cells. Serum samples of healthy Holstein dairy cows (n = 20) and RFM cows (n = 12), with a similar age, parity, weight, and milk yield, were collected to detect Ca²⁺ concentration at prepartum 1-5 d and postpartum 6, 12 and 24 h. Caruncle tissues were collected from healthy (n = 6) and RFM cows (n = 6) at 12 h after calving. Quantitative polymerase chain reaction (Q-PCR) and western blotting (WB) were performed to detect the mRNA and protein levels of STIM1, respectively. UCE cells were cultured by the explant culture method, further purified, and subsequently treated with PmirGLO-STIM1-Mut + miRNA-185 mimics and mirGLO-STIM1-Mut + miRNA-185 NC. Q-PCR and WB were performed to detect mRNA and protein levels of STIM1 with treated miRNA-185 mimics. Serum levels of Ca²⁺ from RFM cows were abnormally decreased at prepartum 1 d and postpartum 6, 12 and 24 h. Expression level of STIM1 was down-regulated in the caruncle tissue of RFM cows. The luciferase activity was decresed about 30.9% by miRNA-185 mimics (p < 0.01), and the mRNA and protein levels of STIM1 were downregulated miRNA-185-mimics. It was suggesting that miRNA-185 might play an important role in RFM through regulating the expression of STIM1.

Cohort Profile: The Chongqing Cancer Cohort Study (CCCS) of the Urban Population in Southwest China

Purpose: Urbanization is causing an increasingly negative effect on public health in China. This study was established to examine the associations between socio-economic and environmental exposures and the potential impact of gene-environment interactions and cancer risk of urban population in Chongqing, China. Participants: The cohort was established in Beibei District of Chongqing in southwest China. Between March 2016 and December 2016, we enrolled 57,332 adults who were 40-69 years of age, and collected baseline data on demographic information, socio-economic status, lifestyle, family and personal disease histories through face-to-face interviews using a standardized questionnaire. Regular follow-up including face-to-face interviews will take place every 5 years. Findings to date: Ninety-nine percent (56658/57332) of the participants completed the baseline assessment. The eligible participants had a mean age of 54.8 years, and 51.42% were females. Nearly three-fifths of participants having a normal BMI (18.5 to 23.9 kg/m2) and one-third being overweight (24.0 to 27.9 kg/m2). Among males, 29.58% were smokers and 21.08% were alcohol users. Among females, 1.49% were smokers and 1.66% were alcohol users. Among all participants, 7.03% of males and 9.08% of females reported their family history of cancer. Future plans: The relationships of modifiable risk factors with the cancer risk will be analyzed. Meanwhile, participants will be closely tracked to minimize loss to follow-up. We plan to construct a risk prediction model on cancer and verify the prediction model by genome-wide association studies (GWAS). The successful completion of this cohort study will allow for better targeting of cancer screening to those at highest risk in urban population of China and provide clinicians and policymakers with a practical predication rule.

Tobacco Smoking and Trends in Histological Subtypes of Female Lung Cancer at The Cancer Hospital of The Chinese Academy of Medical Sciences Over 13 Years

Background: Smoking among Chinese women accounts for a small proportion, but the incidence and mortality rates of female lung cancer is increasing in recent years. Studies found that there were changes in histologic subtypes of lung cancer patients in China. Aim: This study investigated the tobacco smoking and trends in histologic subtypes of female lung cancer in a cancer hospital in China. Methods: Demographic, smoking history and histologic information about female lung cancer patients diagnosed or treated from 2000 to 2012 was collected from Cancer Hospital, Chinese Academy of Medical Science (CHCAMS). Trends of histologic subtypes calculated with annual percentage change (APC). The distribution differences of adenocarcinoma (ADC), squamous cell carcinoma (SCC), small cell lung cancer (SCLC) and the other subtypes between smokers and nonsmokers were calculated by 7th AJCC cancer staging. Results: Totally of 5,870 female cases of lung cancer, including 630 with history of smoking and 5,240 without, were analyzed. The number of female lung cancer patients increased from 509 (2000-2002) to 1744 (2012-2013). The main histologic type of lung cancer was adenocarcinoma (ADC) (72.93%), followed by small cell lung cancer (SCLC) (11.06%), squamous cell carcinoma (SCC) (8.38%) and the other (7.63%). Among smokers, the proportion of SCC decreased from 40.5% to 23.7% (APC = -11.68%, P = 0.005), however, the ADC increased from 35.7% to 50.7% (APC = 8.63%, P = 0.009). In nonsmokers, the ADC was 76.1%, and SCC was 5.9%. ADC increased from 63.1% to 80.6% (APC = -21.33%, P = 0.006), SCC decreased from 13.6% to 4.5% (APC = 3.86%, P = 0.016). Among squamous cell carcinoma, the cases with history of smoking were more likely diagnosed at early stages (I/II: 47.1%) than those at late stages (III, 34.3%; IV, 18.6%). Conclusion: The number of female lung cancer patients was increased in CHCAMS by year of diagnosis. In both smoking and nonsmoking cases, the proportion of adenocarcinoma was increasing. Among the squamous cell carcinoma, smokers seem to find in early stages.

Serial electron crystallography for structure determination and phase analysis of nanocrystalline materials

Serial electron crystallography has been developed as a fully automated method to collect diffraction data on polycrystalline materials using a transmission electron microscope. This enables useful data to be collected on materials that are sensitive to the electron beam and thus difficult to measure using the conventional methods that require long exposure of the same crystal. The data collection strategy combines goniometer translation with electron beam shift, which allows the entire sample stage to be probed. At each position of the goniometer, the locations of the crystals are identified using image recognition techniques. Diffraction data are then collected on each crystal using a quasi-parallel focused beam with a predefined size (usually 300-500 nm). It is shown that with a fast and sensitive Timepix hybrid pixel area detector it is possible to collect diffraction data of up to 3500 crystals per hour. These data can be indexed using a brute-force forward-projection algorithm. Results from several test samples show that 100-200 frames are enough for structure determination using direct methods or dual-space methods. The large number of crystals examined enables quantitative phase analysis and automatic screening of materials for known and unknown phases.

Ultrasonicated graphene oxide enhances bone and skin wound regeneration

In the present study, we investigated the applications of ultrasonicated graphene oxide (UGO) for bone regeneration and skin wound healing. Ultrasonication of a GO suspension increased the dispersion and stability (by increasing the zeta potential) of the GO suspension. UGO has fewer oxygen-containing groups but still displays excellent water dispersion. The UGO supension showed high biocompatibility for human fetal osteoblast (hFOB cells), human endothelial cells (EA.hy 926 cells), and mouse embryonic fibroblasts. Importantly, UGO could support cell attachment and proliferation, in addition to promoting the osteogenesis of seeded cells and the promotion of new bone formation. In addition, a 1% UGO supension enhanced cell migration in an in vitro skin scratch assay and promoted wound closure in an in vivo rat excisional skin defect model. These results showed that UGO offers a good environment for cells involved in bone and skin healing, suggesting its potential application in tissue regeneration.

Coordination Modulation Method To Prepare New Metal-Organic Framework-Based CO-Releasing Materials

Aluminum-based metal-organic frameworks (MOFs), [Al(OH)(SDC)] _n, (H₂SDC: 4,4'-stilbenedicarboxylic acid), also known as CYCU-3, were prepared by means of the coordination modulation method to produce materials with different crystal size and morphology. In particular, we screened several reagent concentrations (20-60 mM) and modulator/ligand ratios (0-50), leading to 20 CYCU x_ y materials ( x: reagent concentration, y = modulator/ligand ratio) with different particle size and morphology. Noteworthy, the use of high modulator/ligand ratio gives rise to a new phase of CYCU-3 (CYCU-3' x_50 series), which was structurally analyzed. Afterward, to test the potential of these materials as CO-prodrug carriers, we selected three of them to adsorb the photo- and bioactive CO-releasing molecule (CORM) ALF794 [Mo(CNCMe₂CO₂H)₃(CO)₃] (CNCMe₂CO₂H = 2-isocyano-2-methyl propionic acid): (i) CYCU-3 20_0, particles in the nanometric range; (ii) CYCU-3 50_5, bar-type particles with heterogeneous size, and (iii) CYCU-3' 50_50, a new phase analogous to pristine CYCU-3. The corresponding hybrid materials were fully characterized, revealing that CYCU-3 20_0 with the smallest particle size was not stable under the drug loading conditions. Regarding the other two materials, similar ALF794 loadings were found (0.20 and 0.19 CORM/MOF molar ratios for ALF794@CYCU-3 50_5 and ALF794@CYCU-3' 50_50, respectively). In addition, these hybrid systems behave as CO-releasing materials (CORMAs), retaining the photoactive properties of the pristine CORM in both phosphate saline solution and solid state. Finally, the metal leaching studies in solution confirmed that ALF794@CYCU-3' 50_50 shows a good retention capacity toward the potentially toxic molybdenum fragments (75% of retention after 72 h), which is the lowest value reported for a MOF-based CORMA to date.

Synthesis and Structure of a Layered Fluoroaluminophosphate and Its Transformation to a Three-Dimensional Zeotype Framework

Two-dimensional zeolitic materials have drawn increasing attention because of their structural diversity, high accessible surface areas, and potential as precursors to form novel three-dimensional (3D) structures. Here we report a new layered fluoroaluminophosphate, denoted as EMM-9 (ExxonMobil Material #9), synthesized in the same synthesis system as that for a previously reported 3D framework structure EMM-8 (framework-type code: SFO) using an F^- medium and 4-(dimethylamino)pyridine (DMAP) as the organic structure-directing agent. The structure of EMM-9 was solved from rotation electron diffraction data and refined against synchrotron powder X-ray diffraction data. The fluoroaluminophosphate layer of EMM-9 is composed of sti composite building units. The DMAP cations are located between the layers. π-π interactions between the DMAP cations and hydrogen bonding between the DMAP cations and layers were identified. The layered EMM-9 structure is closely related to the 3D framework structure of EMM-8 and can be transformed to EMM-8 by calcination.

Nuclear factor erythroid-derived 2-related factor 2 activates glutathione S-transferase expression in the midgut of Spodoptera litura (Lepidoptera: Noctuidae) in response to phytochemicals and insecticides

Detoxication enzymes play an important role in insect resistance to xenobiotics such as insecticides and phytochemicals. We studied the pathway for activating the expression of glutathione S-transferases (GSTs) in response to selected xenobiotics. An assay of the promoter activity of GST epsilon 1 (Slgste1) of Spodoptera litura led to the discovery of a cis-regulating element. An antioxidant response element was activated in response to indole-3-carbinol (I3C) and chlorpyrifos (CPF) and was able to bind with the xenobiotic sensor protein nuclear factor erythroid-derived 2-related factor 2 (SlNrf2). SlNrf2 and Slgste1 were responsive to reactive oxygen species induced by I3C and CPF in a S. litura cell line, as well as in S. litura midguts. SlNrf2 RNA interference (RNAi) reduced the message RNA levels of Slgste1 and the peroxidase activity of GSTs in response to I3C, xanthotoxin, CPF and deltamethrin. SlNrf2 RNAi and inhibitor treatment of GST activity decreased the viability of I3C-treated cells. These results indicate that SlNrf2 activates the expression of GSTs in response to oxidative stresses caused by exposure to xenobiotics.

On the quality of the continuous rotation electron diffraction data for accurate atomic structure determination of inorganic compounds

The continuous rotation electron diffraction (cRED) method has the capability of providing fast three-dimensional electron diffraction data collection on existing and future transmission electron microscopes; unknown structures could be potentially solved and refined using cRED data collected from nano- and submicrometre-sized crystals. However, structure refinements of cRED data using SHELXL often lead to relatively high R1 values when compared with those refined against single-crystal X-ray diffraction data. It is therefore necessary to analyse the quality of the structural models refined against cRED data. In this work, multiple cRED data sets collected from different crystals of an oxofluoride (FeSeO3F) and a zeolite (ZSM-5) with known structures are used to assess the data consistency and quality and, more importantly, the accuracy of the structural models refined against these data sets. An evaluation of the precision and consistency of the cRED data by examination of the statistics obtained from the data processing software DIALS is presented. It is shown that, despite the high R1 values caused by dynamical scattering and other factors, the refined atomic positions obtained from the cRED data collected for different crystals are consistent with those of the reference models refined against single-crystal X-ray diffraction data. The results serve as a reference for the quality of the cRED data and the achievable accuracy of the structural parameters.

Probing the Evolution of Palladium Species in Pd@MOF Catalysts during the Heck Coupling Reaction: An Operando X-ray Absorption Spectroscopy Study

The mechanism of the Heck C-C coupling reaction catalyzed by Pd@MOFs has been investigated using operando X-ray absorption spectroscopy (XAS) and powder X-ray diffraction (PXRD) combined with transmission electron microscopy (TEM) analysis and nuclear magnetic resonance (¹H NMR) kinetic studies. A custom-made reaction cell was used, allowing operando PXRD and XAS data collection using high-energy synchrotron radiation. By analyzing the XAS data in combination with ex situ studies, the evolution of the palladium species is followed from the as-synthesized to its deactivated form. An adaptive reaction mechanism is proposed. Mononuclear Pd(II) complexes are found to be the dominant active species at the beginning of the reaction, which then gradually transform into Pd nanoclusters with 13-20 Pd atoms on average in later catalytic turnovers. Consumption of available reagent and substrate leads to coordination of Cl^- ions to their surfaces, which causes the poisoning of the active sites. By understanding the deactivation process, it was possible to tune the reaction conditions and prolong the lifetime of the catalyst.

An Extra-Large-Pore Zeolite with 24×8×8-Ring Channels Using a Structure-Directing Agent Derived from Traditional Chinese Medicine

Extra-large-pore zeolites have attracted much interest because of their important applications for processing larger molecules. Although great progress has been made in academic science and industry, it is challenging to synthesize these materials. A new extra-large-pore zeolite SYSU-3 (Sun Yat-sen University no. 3) has been synthesized by using a novel sophoridine derivative as an organic structure-directing agent (OSDA). The framework structure was solved and refined using continuous rotation electron diffraction (cRED) data from nanosized crystals. SYSU-3 exhibits a new zeolite framework topology, which has the first 24×8×8-ring extra-large-pore system and a framework density (FD) as low as 11.4 T/1000 ų . The unique skeleton of the OSDA plays an essential role in the formation of the distinctive zeolite structure. This work provides a new perspective for developing new zeolitic materials by using alkaloids as cost-effective OSDAs.

Facile Water-Based Strategy for Synthesizing MoO3-x Nanosheets: Efficient Visible Light Photocatalysts for Dye Degradation

Nanostructured molybdenum oxides are promising materials for energy storage, catalysis, and electronic-based applications. Herein, we report the synthesis of MoO_3-x nanosheets (x stands for oxygen vacancy) via an environmentally friendly liquid exfoliation approach. The process involves the reflux of the bulk α-MoO₃ precursor in water at 80 °C for 7 days. Electron microscopy and atomic force microscopy show that the MoO_3-x nanosheets are a few nanometer thick. MoO_3-x nanosheets exhibit near infrared plasmonic property that can be enhanced by visible light irradiation for a short time (10 min). Photocatalytic activity of MoO_3-x nanosheets for organic dye decolorization is examined using two different dyes (rhodamine B and methylene blue). Under visible light irradiation, MoO_3-x nanosheets make a rapid decolorization for the dye molecules in less than 10 min. The simple synthesis procedure of MoO_3-x nanosheets combined with their remarkable photochemical properties reflect the high potential for using the nanosheets in a variety of applications.

[Ti8Zr2O12(COO)16] Cluster: An Ideal Inorganic Building Unit for Photoactive Metal-Organic Frameworks

Metal-organic frameworks (MOFs) based on Ti-oxo clusters (Ti-MOFs) represent a naturally self-assembled superlattice of TiO₂ nanoparticles separated by designable organic linkers as antenna chromophores, epitomizing a promising platform for solar energy conversion. However, despite the vast, diverse, and well-developed Ti-cluster chemistry, only a scarce number of Ti-MOFs have been documented. The synthetic conditions of most Ti-based clusters are incompatible with those required for MOF crystallization, which has severely limited the development of Ti-MOFs. This challenge has been met herein by the discovery of the [Ti₈Zr₂O₁₂(COO)₁₆] cluster as a nearly ideal building unit for photoactive MOFs. A family of isoreticular photoactive MOFs were assembled, and their orbital alignments were fine-tuned by rational functionalization of organic linkers under computational guidance. These MOFs demonstrate high porosity, excellent chemical stability, tunable photoresponse, and good activity toward photocatalytic hydrogen evolution reactions. The discovery of the [Ti₈Zr₂O₁₂(COO)₁₆] cluster and the facile construction of photoactive MOFs from this cluster shall pave the way for the development of future Ti-MOF-based photocatalysts.

Dextran sulphate sodium (DSS) causes intestinal histopathology and inflammatory changes consistent with increased gut leakiness in chickens

1. The clinical severity, histological changes, indicators of gut leakiness and inflammatory cytokine profiles were studied in chickens with dextran sulphate sodium (DSS)-induced intestinal inflammation. 2. The experimental groups (1.25%, 1.5% and 2.5% DSS) showed clinical signs, such as loose stools and weight loss, which increased with additional treatment days and, as expected, the effects of DSS-induced intestinal inflammation were time and dose-dependent. 3. After 10 d, histological manifestations were evident, including goblet cell depletion, mucus layer loss, significantly shorter villi and a thinner total ileal mucosa. 4. The d(-)-lactate value, which was used as a gut leakiness indicator, was significantly increased in the 2.5% DSS group. 5. Expression of the inflammatory cytokines interleukin-1Beta, tumour necrosis factor alpha and interleukin-10 in the serum significantly increased with DSS treatment. 6. This study indicates that the experimental intestinal inflammation induced by DSS is an ideal model to study the pathogenic mechanisms of intestinal inflammation in chickens and to test the efficacy of therapies.