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H2O2 production by photocatalysis has received considerable attention, while using MOF‐based materials as photocatalysts is still less explored. Ligand functionalization of MOFs is a decoration way at the molecular level, which provides the basis for the further modification of MOFs. In this concept, ligand functionalization of MOFs for photocatalytic H2O2 production has been systematically and extensively discussed. The strategies of ligand functionalization include grafting of functional groups (e. g. amino, methoxyl, boron and alkyl) and multiple ligand decoration. Correspondingly, some specific effects are achieved, e. g. improved charge carrier separation, enhanced O2 adsorption and hydrophobicity, which can realize efficient H2O2 production by photocatalysis. Meanwhile, reaction conditions and activities of photocatalytic H2O2 production have also been explicitly introduced in these studies. At last, the future perspectives are proposed. This concept sheds fresh light on the great potential of ligand functionalization of MOFs for photocatalytic H2O2 production. [ABSTRACT FROM AUTHOR]

Ulcerative colitis (UC), a chronic and refractory nonspecific inflammatory bowel disease, affects millions of patients worldwide and increases the risk of colorectal cancer. Teprenone is an acylic polyisoprenoid that exerts anti-inflammatory properties in rat models of peptic ulcer disease. This in vitro and in vivo study was designed to investigate the effects of teprenone on UC and to explore the underlying mechanisms. Human intestinal epithelial cells (Caco-2 cells) serve as the in vitro experimental model. Lipopolysaccharide (LPS, 1 μg/mL) was employed to stimulate the production of pro-inflammatory cytokines (interleukin [IL]-6, IL-1β, and tumor necrosis factor [TNF]-α), Toll-like receptor-4 (TLR4), MyD88 expression, and NF-κB activation. A trinitrobenzene sulfonic acid (TNBS)-induced chronic UC rat model was employed for the in vivo assay. Pro-inflammatory cytokine stimulation by LPS in Caco-2 cells was inhibited by teprenone at 40 μg/mL through the TLR4/NF-κB signaling pathway. Teprenone attenuated TNBS-induced UC, decreased myeloperoxidase and malondialdehyde, induced TLR4 expression and NF-κB activation, and increased glutathione and zonula occludens-1 level in the rat colonic tissue. Moreover, Fusobacterium, Escherichia coli, Porphyromonas gingivalis elevation, and Mogibacterium timidum decline in UC rats were inhibited by teprenone. Based on our results, the protective effects of teprenone for UC may be related to its ability to modulate the gut microbiota and reduce the inflammatory response. [ABSTRACT FROM AUTHOR]

Drill feed speed significantly affects the measurement accuracy and efficiency of the micro drill resistance instrument. Generally, different speeds are set according to the density of the wood to be drilled. It is necessary to convert the resistance data measured at different drill feed speeds into resistance data at a uniform speed to properly analyze resistance data. In this study, drill resistance data for a Paulownia wood block was measured with a self-made micro drill resistance instrument at different drill feed speeds. We found that the drill resistance is positively correlated with changes in its feed speed and the natural logarithm of change times for feed speed. We developed a conversion algorithm for the micro drill resistance instrument measurements at different feed speeds. The accuracy of the conversion algorithm is up to 95%. The algorithm can be used to convert the drill resistance of Paulownia wood measured at different drill feed speeds; it has reference value for the mutual conversion of other tree species' drill resistance data measured at different feed speeds. This work may provide a feasible solution to improving micro drill resistance instrument accuracy when drill feed speed error is high. [ABSTRACT FROM AUTHOR]

The actions exerted by yawed wind on the crossarm substantially differ from those on the tower body due to the presence of the angle between the crossarm's cross-section and the incoming flow, and this phenomenon deserves a better understanding. Focusing on the tubular crossarms with round-section members, this paper aims to determine insights into wind actions, as affected by various factors, such as the tower type, the mean width to mean height ratio, the solidity ratio, and the wind incidence angle, and thereby derive the wind loads for design. Accordingly, a succession of wind tunnel tests was conducted by using quadrilateral and triangular crossarm models with various solidity ratios and mean width to mean height ratios. The method of direct force measurement (DFM) is employed for the high frequency force balance (HFFB) test to attain the transverse and longitudinal forces on the crossarm simultaneously. It was found that the wind load coefficients increase with increases of the mean width to mean height ratio and decreases of the solidity ratio. Moreover, in the case of the incoming flow perpendicular to the crossarm face, it is concluded that compared to the quadrilateral crossarm, the triangular crossarm possesses a relatively smaller drag coefficient, provided a moderate mean width to mean height ratio of 1.19. Furthermore, an analysis of the experimental results shows that the skewed wind load factor specified in the relevant codes would overestimate the effects of the wind incidence angle and the variations in mean width to mean height ratio, which is evident in the tests but not considered in the codes. It is worth noting that the experimental results show that the crosswind force is pronounced, which is usually ignored in the skewed wind load factor-based approach. Comparatively, using wind load distribution factors seems to be more rational. Thus, the corresponding estimating equations are proposed for the wind load-distribution factors of the crossarms, which agree well with the experimental results. The developed equations would greatly facilitate the determination of wind loads on tubular crossarms. [ABSTRACT FROM AUTHOR]

This study aims to investigate refined wind load parameters on main rods and the influence of wind-loading mode on wind-induced responses of the angle-steel transmission tower. The wind load parameters discussed in this study include drag coefficients, wind load distribution factors and skewed wind load factors. To achieve the aim, wind tunnel tests were conducted to explore aerodynamic loads for integrated frame, single frame, and main rod models of cross-arm and tower body. The wind load parameters of the different models were investigated. In addition, a series of wind-induced vibration simulation was applied to examine the wind-induced responses of an ultra-high voltage (UHV) transmission tower with a long cross-arm under concentrated and distributed wind loads. The simulated results under the two types of wind loads were compared. The results show that the longitudinal drag coefficients of the main rods are smaller than the values of the integrated frame, and equivalent on average to the values of the single frame. The experimental shielding factor of the cross-arm is larger than those in different standards due to the joint drag effects of leeward, upper, and lower faces of the cross-arm in the wind tunnel test. The experimented shielding factor of the tower body is in line with those referring to the Chinese and AS/NZS standards, and slightly larger than those based on the British and JEC standards. The skewed wind load factors of the main rod models are quite different from other models for cross-arm and tower body. The wind-induced vibration simulation suggests that, the wind-loading mode has limited impact on the displacements, accelerations, and gust factors of the transmission tower, but significantly influences the maximum normal stresses (MNSs) of the rods' cross-sections. The MNSs caused by the distributed wind loads are obviously greater than those caused by concentrated wind loads, especially for the rods at the two ends of the cross-arm. [ABSTRACT FROM AUTHOR]

The ovarian reserve determines the success of in vitro fertilization (IVF) and embryo transfer treatment. It predicts the ovarian response in controlled ovarian hyperstimulation cycles. Apoptosis in granulosa cells surrounding oocytes is important for ovarian function and has been closely associated with follicular atresia. PTEN (encoding phosphatase and tensin homolog) is a well-known tumor suppressor gene that functions as a mediator of apoptosis and is crucial for mammal reproduction. In the present study, we analyzed the expression level of PTEN in human granulosa cells and aimed to investigate its association with the ovarian response and clinical outcomes in IVF. Apoptosis in granulosa cells were analyzed using Annexin V-Allophycocyanin staining after PTEN short hairpin RNA lentivirus transfection. Real-time fluorescent quantitative PCR analysis showed that the PTEN transcript level was significantly higher in poor responders and significantly lower in high responders, compared with that in normal responders. However, PTEN expression in the pregnancy group decreased slightly, but not significantly, compared with that in the non-pregnancy group. The apoptosis rate of granulosa cells declined significantly after 24-h transfection of the PTEN-shRNA lentivirus. These results suggest a fundamental role of PTEN in the regulation of follicular development, and that it might be involved in the pathogenesis of follicular dysplasia and ovarian dysfunction. [ABSTRACT FROM AUTHOR]

Modelling and forecasting covariance matrices of asset returns play a crucial role in many financial fields, such as portfolio allocation and asset pricing. The availability of high-frequency intraday data enables the modelling of the realized covariance matrix directly. However, most models in the literature suffer from the curse of dimensionality, i.e. the number of parameters needed increases at the rate of the square of the number of assets. To solve the problem, we propose a factor model with a diagonal Conditional Autoregressive Wishart model for the factor realized covariance matrices. Consequently, the positive definiteness of the estimated covariance matrix is ensured with the proposed model. Asymptotic theory is derived for the estimated parameters. In the extensive empirical analysis, we find that the number of parameters can be reduced significantly; to only about one-tenth of the benchmark model. Furthermore, the proposed model maintains a comparable performance with a benchmark vector autoregressive model for different forecast horizons. [ABSTRACT FROM AUTHOR]

For dendrite graphs from biological experiments on mouse's retinal ganglion cells, a paper by Nakatsukasa, Saito and Woei reveals a mysterious phase transition phenomenon in the spectra of the corresponding graph Laplacian matrices. While the bulk of the spectrum can be well understood by structures resembling starlike trees, mysteries about the spikes, that is, isolated eigenvalues outside the bulk spectrum, remain unexplained. In this paper, we bring new insights on these mysteries by considering a class of uniform trees. Exact relationships between the number of such spikes and the number of T-junctions are analyzed in function of the number of vertices separating the T-junctions. Using these theoretical results, predictions are proposed for the number of spikes observed in real-life dendrite graphs. Interestingly enough, these predictions match well the observed numbers of spikes, thus confirm the practical meaningness of our theoretical results. [ABSTRACT FROM AUTHOR]

Ghrelin is a gastric acyl-peptide that plays an important role in cell proliferation. In the present study, we explored the role of ghrelin in A549 cell proliferation and the possible molecular mechanisms. We found that ghrelin promotes A549 cell proliferation, knockdown of the growth hormone secretagogue receptor (GHSR) attenuated A549 cell proliferation caused by ghrelin. Ghrelin induced the rapid phosphorylation of phosphatidylinositol 3-kinase (PI3K), Akt, ERK, mammalian target of rapamycin (mTOR) and P70S6K. PI3K inhibitor (LY 294002), ERK inhibitor (PD98059) and mTOR inhibitor (Rapamycin) inhibited ghrelin-induced A549 cell proliferation. Moreover, GHSR siRNA inhibited phosphorylation of PI3K, Akt, ERK, mTOR and P70S6K induced by ghrelin. Akt and mTOR/P70S6K phosphorylation was inhibited by LY 294002 but not by PD98059. These results indicate that ghrelin promotes A549 cell proliferation via GHSR-dependent PI3K/Akt/mTOR/P70S6K and ERK signaling pathways. [ABSTRACT FROM AUTHOR]

Abstract: Selectivity of cascade redox reactions: the reduction of nitrobenzene to azoxybenzene and then to azobenzene and the oxidation of benzyl alcohol to benzaldehyde and then to benzoic acid, is discovered to be tuneable via light irradiation over plasmonic gold photocatalysts. The representative photocatalyst of Au/CeO2 was characterized by TEM, EDX, UV-Vis and XPS to determine its morphology, elemental composition, photo absorptivity and oxidation state of gold. The catalytic test results demonstrate that the net contribution of light irradiation correlates with the ability of incident light to excite electrons and light absorption of catalysts. These findings may inspire peer researchers in developing new photocatalytic processes or in designing new photocatalysts for clean chemicals synthesis.Graphical Abstract: [ABSTRACT FROM AUTHOR]

Introduction Certain procaspase-8 mutations are reported to be associated with the progression and prognosis of multiple tumors. However, it remains unclear whether the poor chemotherapy response and frequent relapse after complete remission of patients with acute myeloid leukemia (AML) is also related to procaspase-8 abnormalities. Methods Polymerase chain reaction (PCR) amplification and Sanger sequencing of the procaspase-8 gene ( CASP8 ) were performed. Apoptotic rates were analyzed with Annexin V-FITC staining in cells expressing wild-type (WT) procaspase-8, the Q482H or C360S mutant, or control vector after treatment with or without tumor necrosis factor–related apoptosis-inducing ligand (TRAIL). Western blot analysis was performed to detect activation of procaspase-8 and downstream apoptotic signaling pathway components in those cells. The Co-immunoprecipitation (Co-IP) assays were performed to detect interaction between WT and mutant procaspase-8 proteins. Results AML patients carrying the Q482H mutation were likely to develop chemotherapy resistance. Similar to C360S, The Q482H mutation abolished caspase-8-mediated apoptotic signaling and inhibited TRAIL-induced apoptosis. The Q482H mutation impaired procaspase-8 dimerization, thus preventing the self-activation of procaspase-8. Conclusion The procaspase-8 Q482H mutation in AML patients abolishes caspase-8-mediated apoptosis by impairing procaspase-8 dimerization. [ABSTRACT FROM AUTHOR]

microRNAs (miRNAs) have been reported to play crucial roles in malignant tumor progression, including cell development, proliferation, and progression. Increasing evidence suggests that miR-495 functions as either an oncogene or tumor suppressor in several tumor types. However, its biological role in the development of colorectal cancer (CRC) still remains unclear. In this study, we found that miR-495 expression level was remarkably down-regulated in CRC tissues samples and cell lines when compared to adjacent normal tissues and cell line by using qRT-PCR detection. Ectopic expression of miR-495 by mimic transfection significantly suppressed CRC cell proliferation and colony formation, inhibited migration and invasion, and induced apoptosis according to CCK-8, colony formation, transwell, and flow cytometry assays. Furthermore, bioinformatics and luciferase reporter assays verified that family with sequence similarity 83, member D (FAM83D) was a direct target of miR-495 in CRC cells, and FAM83D was confirmed to be upregulated in human CRC tissues and reversely correlated with miR-495 expression. In addition, rescue experiments revealed that restoration of FAM84D could partially abrogate the inhibitory effect of miR-495 overexpression on CRC cell proliferation and metastasis. Further mechanic investigations also verified that the PTEN/P13K/AKT/mTOR pathway was involved in the miR-495/FAM83D-mediated CRC cell progression. Our findings identified that miR-495 acted as a critical tumor suppressor by directly targeting FAM83D during CRC development and therefore represented as a potential biomarker for CRC therapy. [ABSTRACT FROM AUTHOR]

Background: Pathogenic PAK1 variants were described to be causative of neurodevelopmental disorder with macrocephaly, seizures, and speech delay. Herein, we present a de novo PAK1 variant combine with a de novo terminal 1q microdeletion in a Chinese pediatric patient, aiming to provide more insights into the underlying genotype–phenotype relationship. Methods: Enrolled in this study was a 6-year-old girl with clinical features of global developmental delay, severe intellectual disability, speech delay, and seizures from Quanzhou region of China. Karyotype and chromosomal microarray analysis (CMA) were performed to detect chromosome abnormalities in this family. Whole exome sequencing (WES) was performed to investigate additional genetic variants in this family. Results: No chromosomal abnormalities were elicited from the entire family by karyotype analysis. Further familial CMA results revealed that the patient had a de novo 2.7-Mb microdeletion (arr[GRCh37] 1q44(246,454,321_249,224,684) × 1]) in 1q44 region, which contains 14 OMIM genes, but did not overlap the reported smallest region of overlap (SRO) responsible for the clinical features in 1q43q44 deletion syndrome. In addition, WES result demonstrated a de novo NM_002576: c.251C > G (p.T84R) variant in PAK1 gene in the patient, which was interpreted as a likely pathogenic variant. Conclusion: In this study, we identify a novel PAK1 variant associated with a terminal 1q microdeletion in a patient with neurodevelopmental disorder. In addition, we believe that the main clinical features may ascribe to the pathogenic variant in PAK1 gene in the patient. [ABSTRACT FROM AUTHOR]

In this study, isomerization of styrene oxide to phenyl acetaldehyde was investigated over a series of TS-1 catalysts with different crystal sizes and post-treatment methods under a gas-phase atmosphere free of solvents. The physicochemical properties of the samples were characterized by a combination of N 2 adsorption, XRD, NH 3 -TPD, UV–vis, FT-IR and SEM. By the characterization of catalysts and investigation of their catalytic performances, results indicated that nano size TS-1 exhibited better anti-coking ability and phenyl acetaldehyde selectivity than micro size TS-1. Additionally, TPAOH treatment led to the development of considerable mesoporosity without significant destruction of its intrinsic zeolite properties. The results highlighted that the existence of well-developed hierarchical pore systems in TS-1-O could reduce diffusion path length and enhance transport of phenyl acetaldehyde out of the zeolite crystals, thus markedly improving catalytic stability and selectivity. However, upon NaOH treatment, the micropore structures were irreversibly destroyed accompaning with the amorphization of the zeolite crystals. [ABSTRACT FROM AUTHOR]

The catalytic performance of the isomerization of styrene oxide to phenyl acetaldehyde was investigated over different modified beta catalysts under gas-phase atmosphere free of solvents. The physicochemical properties were characterized by a combination of X-ray diffraction (XRD), N adsorption, Fourier transform infrared spectroscopy (FT-IR), Magic Angle Spinning Nuclear Magnetic Resonance (MAS-NMR), NH-Temperature programmed desorption (NH-TPD) and thermo gravimetric analysis (TGA), etc. Acid sites with stronger strength are responsible for the formation of condensation products and fast deactivation of catalysts. The obtained results also demonstrate that the introduction of boron atoms can create suitable acid strength and acid distribution without significantly destroying its microporous structures. Therefore, BAl-BEA sample is highly active and selective for the rearrangement of styrene oxide as well as very stable to deactivation. Graphical Abstract: [ABSTRACT FROM AUTHOR]

Both autologous and allogeneic stem cell transplantation (auto- and allo-SCT) are treatment choice for adults with acute myeloid leukemia (AML) after complete remission (CR). However, the decision-making remains controversial in some situations. To figure out the treatment choice, we retrospectively investigated 172 consecutive patients with primary AML who received auto- ( n = 46) or allo-SCT ( n = 126) from a single transplant center. Auto- and allo-SCT group demonstrated comparable overall survival (OS) and disease-free survival (DFS) ( P = 0.616, P = 0.559, respectively). Cytogenetic classification and minimal residual disease (MRD) after one course of consolidation were identified as independent risk factors for DFS (hazard ratio (HR), 1.800; 95% CI, 1.172–2.763; P = 0.007; HR, 2.042; 95%CI, 1.003–4.154; P = 0.049; respectively). We subsequently found that auto- and allo-SCT offered comparable DFS to patients with favorable or intermediate risk and were tested MRD neg after one course of consolidation ( P = 0.270) otherwise auto-SCT were inferior due to increased risk of leukemia relapse. Our study indicated that the combination of cytogenetic classification and MRD monitoring correlated with outcome of auto- versus allo-SCT and might help the choice between the two types of SCT for adults with primary AML, which is of significance for patients with expected intermediate prognosis in the current scenario. [ABSTRACT FROM AUTHOR]

• Strategies and purposes of chemical etching on MOFs are summarized. • Key parameters and mechanism of each etching strategy are discussed. • Applications and perspectives of etched MOFs are presented. Rational structure and function modification of metal organic frameworks (MOFs) would enable them with desirable properties. In this regard, MOF modification by chemical etching has been extensively studied, aiming to regulate the pore structure, reshape MOF surface, construct complex structure, manipulate defects, introduce heteroatoms and realize the self-templated conversion to layered metal hydroxides (LDHs). Distinctively, the resultant etched MOFs and etched MOF-based materials have displayed distinctive properties associated with better performance in diverse applications as compared to pristine MOFs. Given the advantages of etching over other technologies, a review focusing on the topic of "etching MOFs" is highly required. Here, the strategies to modify MOFs by chemical etching are broadly classified into four categories including pore engineering, surface/facet modification, defect modification and self-templated conversion to LDHs. In particular, the mechanism and key parameters of each etching strategy on various MOFs are fully discussed, followed by the utilization of etched MOFs and etched MOF-derived materials in diverse applications. Finally, current challenges and research directions for the further development of etching MOFs are proposed. [ABSTRACT FROM AUTHOR]

Inference of population structure from genetic data plays an important role in population and medical genetics studies. With the advancement and decreasing cost of sequencing technology, the increasingly available whole genome sequencing data provide much richer information about the underlying population structure. The traditional method originally developed for array‐based genotype data for computing and selecting top principal components (PCs) that capture population structure may not perform well on sequencing data for two reasons. First, the number of genetic variants p is much larger than the sample size n in sequencing data such that the sample‐to‐marker ratio n/p$n/p$ is nearly zero, violating the assumption of the Tracy‐Widom test used in their method. Second, their method might not be able to handle the linkage disequilibrium well in sequencing data. To resolve those two practical issues, we propose a new method called ERStruct to determine the number of top informative PCs based on sequencing data. More specifically, we propose to use the ratio of consecutive eigenvalues as a more robust test statistic, and then we approximate its null distribution using modern random matrix theory. Both simulation studies and applications to two public data sets from the HapMap 3 and the 1000 Genomes Projects demonstrate the empirical performance of our ERStruct method. [ABSTRACT FROM AUTHOR]

Zeolitic imidazolate frameworks (ZIFs) have attracted considerable attention for many potential applications because they have a unique porous structure and excellent thermal and chemical stabilities. In recent years, significant efforts have been made to develop different methods for the controllable synthesis of ZIFs with desirable crystal structure and morphologies, and for decreasing the excessive amounts of organic ligands and solvents used in the synthesis process to reduce the costs and environmental impacts. This paper highlights the strategies recently reported, including the controllable synthesis of ZIFs with desirable morphologies and pore structure using a surfactant and a template in aqueous solution, the synthesis of ZIF particles and nanocrystals in base solution, and the dry gel and mechanochemical syntheses of ZIFs with minimal solvent usage. [ABSTRACT FROM AUTHOR]

Objective: A number of studies have reported an association of GDF5 with osteoarthritis (OA) but have produced some divergent findings and their interpretation may not be straightforward. Methods: We investigated the association between GDF5 and OA using meta-analytic techniques, combining all published data up to Nov 2014. 16 independent samples from 11 research teams contributed data on SNP rs143383 (located in the 5'-UTR of GDF5) and knee, hip, and hand OA. The total number of cases and controls for this marker was 7,965 and 12,747 for knee OA, 6,363 and 9,727 for hip OA, and 4,335 and 5,991 for hand OA, respectively. The ORs for each OA phenotype were synthesized using random-effects models or fixed-effects models depending on the test of between-study heterogeneity. Results: Using a random-effect model, a significant difference was identified between patients with knee OA and controls for the T-allele of rs143383 (Subtotal OR = 1.18, 95 % CI=1.10-1.27, P=1.84 × 10). For hand OA, a moderate association was also observed (Subtotal OR = 1.09, 95 % CI = 1.02-1.16, P = 0.01) for SNP rs143383 in the combined population. However, non-statistically significant summary OR of hip OA was found in both combined studies (Subtotal OR = 1.22, 95 % CI = 0.97-1.53, P = 0.09) and European studies (Subtotal OR = 1.16, 95 % CI = 0.91-1.48, P = 0.23). Conclusions: Our results demonstrate that SNP rs143383 of GDF5 is a compelling risk factor for both knee and hand OA, and provide further support for GDF5 in the etiology of OA. Further efforts to identify functional variants of GDF5 in in vitro and in vivo will be required. [ABSTRACT FROM AUTHOR]

This paper discusses the problem of estimating the population spectral distribution from high-dimensional data. We present a general estimation procedure that covers situations where the moments of this distribution fail to identify the model parameters. The main idea is to use generalized functional expectations as a substitute for the moments. Beyond the consistency, we also prove a central limit theorem for the proposed estimator. Simulation experiments illustrate the implementation of the estimation procedure. An application to the analysis of the eigenvalues of the sample correlation matrix of S&P 500 daily stock returns is proposed. [ABSTRACT FROM AUTHOR]

Since the introduction of Dyson's Brownian motion in early 1960s, there have been a lot of developments in the investigation of stochastic processes on the space of Hermitian matrices. Their properties, especially, the properties of their eigenvalues have been studied in great detail. In particular, the limiting behaviours of the eigenvalues are found when the dimension of the matrix space tends to infinity, which connects with random matrix theory. This survey reviews a selection of results on the eigenvalues of stochastic processes from the literature of the past three decades. For most recent variations of such processes, such as matrix-valued processes driven by fractional Brownian motion or Brownian sheet, the eigenvalues of them are also discussed in this survey. In the end, some open problems in the area are also proposed. [ABSTRACT FROM AUTHOR]

Highlights: [•] Mesoporous TiO2 was prepared using an evaporation-induced self-assembly method. [•] The obtained TiO2 had hexagonal mesostructure with highly crystalline anatase phase. [•] Mesoporous TiO2 exhibited high sunlight-driven photocatalytic activity in dye degradation. [•] The charge-dependent photocatalytic behaviour of the mesoporous TiO2 was investigated. [Copyright &y& Elsevier]

The carbonization of a newly reported two-dimensional zeolitic imidazolate framework (ZIF-L) with leaf-like morphology was investigated by TG, SEM, XRD and XPS. ZIF-L flakes were thermally stable at up to 200°C, and completely transformed into an amorphous carbonaceous material after heat treatment in nitrogen at 550°C. A carbon composite membrane was then prepared by deposition of ZIF-L flakes on a porous alumina support and then direct carbonization of ZIF-L film. During the carbonization, the ZIF-L membrane reorganized into a nanoporous carbon composite membrane composed of ZnO nanoparticles and leaf-like carbon flakes. The resulting nanoporous carbon composite membrane exhibited a narrow micropore size distribution, and it had higher BET surface area than the ZIF-L flakes. Gas separation permeation experiments showed that the carbon composite membrane had a high H2 permeance of 3.5×10−6 molm−2 s−1 Pa−1, and moderate H2/N2 and H2/CO2 ideal selectivities of 6.2 and 4.9, respectively. This work presents a simple and effective method for preparing functional nanoporous carbon composite membranes from ZIFs (or MOFs) for many potential applications. [ABSTRACT FROM AUTHOR]

Abstract: Estimating the number of spikes in a spiked model is an important problem in many areas such as signal processing. Most of the classical approaches assume a large sample size whereas the dimension of the observations is kept small. In this paper, we consider the case of high dimension, where is large compared to . The approach is based on recent results of random matrix theory. We extend our previous results to a more difficult situation where some spikes are equal, and compare our algorithm to an existing benchmark method. [Copyright &y& Elsevier]

Highlights: [•] ZIF-8 prepared from stoichiometric metal and ligand aqueous solutions. [•] The role of ammonium hydroxide for ZIF-8 preparation was discussed. [•] Concentrated precursor solution was used to prepare ZIF-8. [•] Highly thermally stable ZIF-8 crystals with uniform shapes and high surface areas. [Copyright &y& Elsevier]

Toluene was discovered as the structure template for the synthesis of large-cage RHO-type zeolitic imidazolate frameworks (ZIF-11 and ZIF-12) in an alcohol-based solution where benzimidazole–toluene interactions play a decisive structure-directing role; otherwise it leads to small-cage SOD-type ZIF-7 and ZIF-9 without toluene. The specific π–π interactions make toluene molecules adopt a specific and oriented arrangement in the unit cell. XRD intensity of the (100) plane is strongly dependent on the amount of toluene: apparent intensity degradation is observed after removing toluene by solvent exchange or thermal treatment, and the peak intensity is recoverable by filling of the pores with toluene vapor. More-polar methanol as compared to ethanol is favorable for the formation of RHO-type ZIFs due to the enhanced interactions between toluene and imidazolate linkers. [ABSTRACT FROM AUTHOR]

This paper reports a phase inversion method for the preparation of macroporous polysulfone (PS) composite spheres through a single orifice spinneret. Surfactant F127 was pre-added in the polymer solution as a surface pore-forming agent, and different amount of zeolitic imidazolate framework-8 (ZIF-8) particles were incorporated to form the ZIF-8/polysulfone (ZIF-8/PS)-composite spheres. ZIF-8 and polymer acted as the adsorbent and binder in the final composite spheres, respectively. The fabrication conditions, such as the types of the surfactant, the amount of the surfactant, and ZIF-8 added in the polymer solution, were investigated. Nitrogen and carbon dioxide sorption analysis indicated the ZIF-8/PS composite spheres had similar properties as the pure ZIF-8 particles, and the active sites of ZIF-8 in the polymer composites were well exposed. The composite spheres exhibited advantages of easy handling and recycling over ZIF-8 particles, and this phase inversion method can be extended to prepare other polymer composite spheres. [ABSTRACT FROM AUTHOR]

Room to breathe: An efficient method for the synthesis of zeolitic imidazolate framework‐7 (ZIF‐7) in ethanol/water at room temperature is reported. The ZIF‐7 undergoes a reverse‐phase transition from large pore (lp)‐phase to narrow pore (np)‐phase under heat treatment and from np‐phase back to lp‐phase in ethanol solution. [ABSTRACT FROM AUTHOR]

Abstract: Alumina hollow fiber supported ZIF-8 membranes and crystals have been prepared in diluted aqueous solutions. The concentration of the aqueous solution, synthesis temperature and time were examined in detail. The particle sizes of ZIF-8 crystals increased from about 90 nm to 5.0 μm with the increase of the dilution of the aqueous synthesis solution. Continuous ZIF-8 membranes were obtained by using the diluted synthesis solution with a Zn2+:2-methylimidazolate:H2O molar ratio of 1:70:4952 at 50–70 °C for 24 h, and their thicknesses were about 0.8–1.4 μm. Gas permeation tests indicated the ZIF-8 membranes are continuous and compact. The schematic formation of ZIF-8 membranes and crystals were proposed, and only in the diluted aqueous solution, ZIF-8 membranes and crystals could be prepared at the same time. [Copyright &y& Elsevier]

Abstract: A new synthesis method was developed to synthesize ZIF-8 membrane by infiltrating precursors into a porous alumina support as a seed-and-nutrient layer, and subsequent solvothermal synthesis. A precursor layer with a thickness of about 10μm was formed inside the porous alumina support and the ZIF-8 membrane grew from both the seeds embedded in the precursor layer and the synthesis solution under solvothermal synthesis conditions. The effects of the solvothermal synthesis temperature and time were investigated, and a continuous and stable ZIF-8 membrane was prepared at 120°C for 8h. Gas permeation tests indicated the membrane synthesized at 120°C for 8h was continuous and compact, and had H2/N2 ideal selectivity of 5.7 with a H2 permeance of 1.7×10−7 molm−2 s−1 Pa−1. [Copyright &y& Elsevier]

This paper provides a central limit theorem for a consistent estimator of population eigenvalues with large multiplicities based on sample covariance matrices. The focus is on limited sample size situations, whereby the number of available observations is comparable in magnitude to the observation dimension. An exact expression as well as an empirical, asymptotically accurate, approximation of the limiting variance is derived. Simulations are performed that corroborate the theoretical claims. [ABSTRACT FROM AUTHOR]

Abstract: Zeolitic imidazolate framework-8 (ZIF-8)/chitosan composites were prepared in the chitosan hydrogels. The concentrations of the chitosan and the alkaline solution were varied to the synthesis of the ZIF-8/chitosan composites. In the chitosan hydrogels with the addition of ammonium hydroxide solution, the resulting ZIF-8 crystals exhibited an unusual XRD structure that the XRD peak at about 18o (222) became the strongest. The XRD peak intensity ratio of (222)/(011) increased from 0.68 to 1.5–5.2 in the presence of chitosan hydrogels. ZIF-8/chitosan composites (FC2) were composed of aggregated nanosized particles, and exhibited a higher CO2 adsorption than normal ZIF-8 crystals. After removing chitosan from FC2, XRD pattern of the resulting ZIF-8 crystals returned to the normal state and the morphology kept the same as the composite. [Copyright &y& Elsevier]

Abstract: The imprinted gene Grb10 influences fetal growth, adult behavior and tumor formation. Investigating this gene often involves consecutive passaging of cells in vitro. We analyzed changes in Grb10 DNA methylation and histone modifications in serially passaged adult mouse tail-tip fibroblast cells with bisulfite genomic sequencing method and chromatin immunoprecipitation (ChIP) respectively. There was a significant reduction in global DNA methylation, but no changes in methylation at CpG island 1 (CGI1) of Grb10. There were no changes in methylation at histone H3K4me2, but less methylated histone H3K27me3 was detected, along with more of the acetylated histones H3Ac and H4Ac. The major-type transcript level of Grb10 in fibroblasts increased mildly after extended cultivation. These results suggest consecutive passaging may affect epigenetic modifications of Grb10 in adult fibroblast cells. [Copyright &y& Elsevier]

Abstract: This paper reports on the effect of precursor gel preparation on the microstructural formation of aluminophosphate-5 (AlPO4-5) molecular sieves in the hydrothermal synthesis. The morphology of AlPO4-5 crystal changed from sphere to ellipse with two symmetrical craters when the aluminophosphate precursor gel was prepared via dropwise addition of acid and TEA under strong stirring, and continuous stirring overnight during the gel aging process. The results also showed that both of well-crystallized spherical and elliptical AlPO4-5 crystals covered by the fibrous crystals could be hydrothermally synthesized at 150 oC for 4h or longer. The average particle size of spherical AlPO4-5 samples was about 35–45μm in diameter, whereas the elliptical AlPO4-5 exhibited approximately 13μm in width and 15μm in length. [Copyright &y& Elsevier]

Abstract: This paper reports a new phase inversion spinning method for the preparation of ultrafine hollow fiber membranes through a single orifice spinneret. An oily additive is pre-added in the polymer dope solution as a bore-forming agent. During the rapid solvent extraction and phase separation processes, the oil is pushed by the external solution (coagulant) to the center of the fiber, and thus the hollow fiber membranes can be obtained by washing away the oil. To demonstrate this new method, ultrafine polysulfone and yttria stabilized zirconia hollow fiber membranes were fabricated using a stainless steel syringe tip as a simple orifice spinneret. The fabrication conditions, including the sizes of syringe tips, contents and types of the oily additives were investigated. Gas permeation test indicates the polysulfone hollow fiber membrane had no large defects. The potential benefits of concave surfaces arising from oil droplets in terms of mechanical properties were also discussed. [Copyright &y& Elsevier]

This article deals with the problem of estimating the covariance matrix of a series of independent multivariate observations, in the case where the dimension of each observation is of the same order as the number of observations. Although such a regime is of interest for many current statistical signal processing and wireless communication issues, traditional methods fail to produce consistent estimators and only recently results relying on large random matrix theory have been unveiled. In this paper, we develop the parametric framework proposed by Mestre, and consider a model where the covariance matrix to be estimated has a (known) finite number of eigenvalues, each of it with an unknown multiplicity. The main contributions of this work are essentially threefold with respect to existing results, and in particular to Mestre's work: To relax the (restrictive) separability assumption, to provide joint consistent estimates for the eigenvalues and their multiplicities, and to study the variance error by means of a Central Limit Theorem. [ABSTRACT FROM PUBLISHER]

Background: Pathogenic PAK1 variants were described to be causative of neurodevelopmental disorder with macrocephaly, seizures, and speech delay. Herein, we present a de novo PAK1 variant combine with a de novo terminal 1q microdeletion in a Chinese pediatric patient, aiming to provide more insights into the underlying genotype–phenotype relationship. Methods: Enrolled in this study was a 6-year-old girl with clinical features of global developmental delay, severe intellectual disability, speech delay, and seizures from Quanzhou region of China. Karyotype and chromosomal microarray analysis (CMA) were performed to detect chromosome abnormalities in this family. Whole exome sequencing (WES) was performed to investigate additional genetic variants in this family. Results: No chromosomal abnormalities were elicited from the entire family by karyotype analysis. Further familial CMA results revealed that the patient had a de novo 2.7-Mb microdeletion (arr[GRCh37] 1q44(246,454,321_249,224,684) × 1]) in 1q44 region, which contains 14 OMIM genes, but did not overlap the reported smallest region of overlap (SRO) responsible for the clinical features in 1q43q44 deletion syndrome. In addition, WES result demonstrated a de novo NM_002576: c.251C > G (p.T84R) variant in PAK1 gene in the patient, which was interpreted as a likely pathogenic variant. Conclusion: In this study, we identify a novel PAK1 variant associated with a terminal 1q microdeletion in a patient with neurodevelopmental disorder. In addition, we believe that the main clinical features may ascribe to the pathogenic variant in PAK1 gene in the patient. [ABSTRACT FROM AUTHOR]

Abstract: A pyrolysis synthesis method was developed to prepare ceramic nanoparticles for the fabrication of solid oxide fuel cells. Furfuryl alcohol was used as a polymerizable solvent to dissolve metal nitrates and then polymerized into poly(furfuryl alcohol) (PFA). During the pyrolysis at 600°C, a mixture of nitrates/PFA was converted into ceramic nanoparticles/carbon networks nanocomposite, and the carbon networks act as a barrier to prevent the aggregation of newly formed nanoparticles during particle crystallization. Dispersible nanoparticles with particle sizes ranging from 40nm to 200nm were obtained after burning off carbon networks in air. As an example, Ce0.8Sm0.2O1.9 nanoparticles were synthesized to prepare solid oxide fuel cells, and the fuel cells achieved maximum power densities of 444.5, 625.5 and 684mWcm−2 at 500°C, 550°C and 600°C, respectively. Our study shows that the pyrolysis synthesis method described here is promising for the effective synthesis of high quality ceramic nanoparticles. [Copyright &y& Elsevier]

Abstract: In the spiked population model introduced by Johnstone (2001) , the population covariance matrix has all its eigenvalues equal to unit except for a few fixed eigenvalues (spikes). The question is to quantify the effect of the perturbation caused by the spike eigenvalues. Baik and Silverstein (2006) establishes the almost sure limits of the extreme sample eigenvalues associated to the spike eigenvalues when the population and the sample sizes become large. In a recent work Bai and Yao (2008) , we have provided the limiting distributions for these extreme sample eigenvalues. In this paper, we extend this theory to a generalized spiked population model where the base population covariance matrix is arbitrary, instead of the identity matrix as in Johnstone’s case. As the limiting spectral distribution is arbitrary here, new mathematical tools, different from those in Baik and Silverstein (2006) , are introduced for establishing the almost sure convergence of the sample eigenvalues generated by the spikes. [Copyright &y& Elsevier]

Abstract: This paper presents the synthesis of zeolitic imidazolate framework (ZIF)-8 membranes on the outer surface of alumina hollow fibers using a concentrated synthesis gel. The resulting membranes were characterized by X-ray diffraction, scanning electron microscopy, focused ion beam/scanning electron microscopy and high-resolution transmission electron microscopy. The results showed that the crystalline ZIF-8 membranes were compact and continuous, and contained micro-cavities. Single gas permeances of H2, N2, CH4 and CO2 were determined as a function of permeation time at 25°C. H2, N2 and CH4 permeances almost did not change with the permeation time. However, CO2 permeance decreased from 9.8×10−8 to 1.7×10−8 mol/sm2 Pa within 12h, and CO2 permeation led to an unrecoverable reduction in gas permeation rates in the further permeation experiments. After the first round tests, H2, N2, CH4 and CO2 permeances in the second round permeation tests dropped by 40%, 24%, 11%, and 6%, and remained constant in the further repeated measurements; the equilibrium ideal selectivities of H2/CO2, N2/CO2 and CH4/CO2 were 32.2, 12.9, and 11.9, respectively; the H2/CO2 separation factor was 7.1 for a H2/CO2 binary mixture (45% H2). The small CO2 permeance should arise from the strong CO2 adsorption in ZIF-8 membranes with micro-cavities, and the adsorbed CO2 partially blocked the gas permeation. [Copyright &y& Elsevier]

Abstract: A three-dimensional (3D) fibrous cathode of solid oxide fuel cell was fabricated by using eggshell membranes (ESMs) as the template. This cathode possesses high porosity and interconnectivity, and low polarization resistance. A single fuel cell with the 3D fibrous Sm0.5Sr0.5CoO3/Ce0.8Sm0.2O1.9 cathode shows significantly improved performances at low operating temperatures (500–600°C) as compared with the cell prepared with the ESM-templated cluster cathode in our previous study. [Copyright &y& Elsevier]

Crystallization of sodalite was studied in an ethanol–Na2O–Al2O3–SiO2–H2O system. The addition of ethanol was observed to significantly affect the crystallization process and final crystal sizes and morphologies. Micron-sized sodalite particles with disc and thread-ball-like shapes were produced at low ethanol contents whereas sodalite particles with core-shell nanostructures were dominant at high ethanol contents. Prolongation of the reaction time led to hollow architectures with polycrystalline shells. This study showed that the formation of core-shell and hollow sodalite structures followed a surface crystallization process, including the following steps: the formation of amorphous spherical aggregates, multiple nucleation on the surface, growth of shell nanocrystals, and amorphous core digestion. The present work provides new insights into a better understanding of the role of ethanol in zeolite crystallization, and controllable synthesis of sodalite crystals with different morphologies. [ABSTRACT FROM AUTHOR]

Abstract: The effect of addition of trace amount of KOH as co-catalyst on low boiling point organic amine-catalyzed transesterification for biodiesel production was investigated. Three different organic amines, tri-ethylamine, di-ethylamine and tert-butylamine, were used as catalysts, and the maximum amount of KOH that could be added to these organic amine-catalyzed systems was 367.1mg/kg oil. Under such circumstance, KOH could be left in the resultant biodiesel and no washing was needed to remove it as the concentration of K+ in the biodiesel met EN 14214 standards. Addition of trace amount of co-catalyst KOH with an amount of 367.1mg/kg oil resulted in the organic amine-catalyzed transesterification under milder reaction conditions than those without addition of KOH to achieve >90% yield of methyl ester. Furthermore, side reactions that occurred in the pure organic amine-catalyzed systems could not be detected after addition of trace amount of KOH, as evidenced by the NMR results. [Copyright &y& Elsevier]

Abstract: Mesoporous carbons with specific surface areas in the range of 409–937m2 g−1, mesopore volumes in the range of 0.55–2.26cm3 g−1 and mesopore volume fraction higher than 86% are prepared by using crude attapulgite, calcined attapulgite and HCl-treated attapulgite as inorganic templates and furfuryl alcohol as the carbon source through a vapor deposition polymerization (VDP) method at 130°C. The influences of VDP time, the calcination temperature and HCl concentration on the pore structure of the resultant carbons are investigated. The results indicate that the optimized VDP time, the calcination temperature and the HCl concentration are 6h, 800°C and 5M, respectively, and the corresponding carbons have the maximum surface areas and mesopore volumes. Adsorption of tannic acid on the mesoporous carbons in tannic acid aqueous solution with an initial concentration of 200mgl−1 at 20°C reveals that the equilibrium adsorption capacities (q e) are in the range of 111–464mgg−1. The mesoporous carbon prepared from attapulgite calcined at 800°C (C–T 800-6) exhibits the highest specific surface area (937m2 g−1), the largest mesopore volume (2.26cm3 g−1) and the highest q e (464mgg−1) among all the resultant carbons. [Copyright &y& Elsevier]

Abstract: MnAPO-5 was prepared by a microwave-assisted vapor-phase transport method at 180°C in short times. The products were characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectra, UV–vis spectroscopic measurement, NH3-temperature-programmed desorption and esterification reaction. It was found that dry gels prepared with aluminum isopropoxide, phosphoric acid and manganese acetate could be transferred to MnAPO-5 in the vapors of triethylamine and water by the microwave-assisted vapor-phase transport method at 180°C for less than 30min. The crystallization time was greatly reduced by the microwave heating compared with the conventional heating. The resulting MnAPO-5 exhibited much smaller particle sizes, higher surface areas and slightly higher catalytic activity in the esterification of acetic acid and butyl alcohol than those prepared by the conventional vapor-phase transport method and hydrothermal synthesis. [Copyright &y& Elsevier]

Abstract: SAPO-34 films coated on cordierite honeycombs were synthesized by a vapor phase transport (VPT) technique. X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetry (TG) and differential scanning calorimeter (DSC) were used to characterize the films. It was found that SAPO-34 films could be prepared on the cordierite honeycombs only when triethylamine (TEA) was presented in both the liquid phase and the SAPO-34 synthesis sol. The loading of SAPO-34 could be adjusted by changing the reaction conditions, such as the impregnation time and the molar ratio of SiO2/Al2O3 in the synthesis sol. Continuous SAPO-34 films, with a thickness of ca. 20–60μm, were composed of microsized crystals and the adhesion between SAPO-34 films and cordierites was strong. [Copyright &y& Elsevier]

Abstract: A sizeable proportion of adult pedestrians involved in vehicle-versus-pedestrian accidents suffer head injuries, some of which can lead to lifelong disability or even death. To understand head injury mechanisms, in-depth accident analyses and accident reconstructions were conducted. A total of 120 adult pedestrian accident cases from the GIDAS (German in-depth accident study) database were analyzed, from which 10 were selected for reconstruction. Accident reconstructions initially were performed using multi-body system (MBS) pedestrian and car models, so as to calculate head impact conditions, like head impact velocity, head position and head orientation. These impact conditions then were used to set the initial conditions in a simulation of a head striking a windshield, using finite element (FE) head and windshield models. The intracranial pressure and stress distributions of the FE head model were calculated and correlated with injury outcomes. Accident analysis revealed that the windshield and its surrounding frames were the main sources of head injury for adult pedestrians. Reconstruction results indicated that coup/contrecoup pressure, Von Mises and shear stress were important physical parameters to estimate brain injury risks. [Copyright &y& Elsevier]

Abstract: This paper presents a method for the preparation of magnetic hollow ZSM-5/Ni composite spheres. ZSM-5/Ni/PS spheres were firstly synthesized by assembling ZSM-5 nanoparticles on the surfaces of Ni/PS spheres, followed by hydrothermal treatment to form a compact ZSM-5 layer. Magnetic hollow ZSM-5/Ni spheres were subsequently obtained by calcination and reduction of the ZSM-5/Ni/PS spheres. The samples were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), thermogravimetry (TG), energy dispersive X-ray spectroscopy (EDX), temperature-programmed reduction (TPR) and a vibrating sample magnetometer (VSM). A continuous ZSM-5 layer with a thickness of 400nm was formed on the surface of Ni/PS spheres after one cycle of adsorption of ZSM-5 nanoparticles and hydrothermal treatment at 80°C for 36h. By changing the hydrothermal treatment time, the thickness of zeolite layer can be controlled. The hollow ZSM-5/Ni spheres inherited magnetic property from the nickel layer and their magnetization value could be adjusted by varying the thickness of the nickel layers. [Copyright &y& Elsevier]