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Pure metal nanowires (NWs) are one-dimensional nanomaterials with distinctive properties for various applications. Nevertheless, mass-growth forests have not been developed because of vapor pressure limitations, chemical reduction problems, or both. We succeeded in the mass growth of aluminum (Al) NW forests at desired locations by controlling atomic diffusion within the solid film. Whereas prior attention has focused only on how to increase the driving force, we show that focused ion beam irradiation created localized regions of high stress, which provided pathways for atomic diffusion as well as nuclei and driving forces for vertical NW growth. The underlying growth process could in principle be extended to other metals. [ABSTRACT FROM AUTHOR]

Agro-based small and medium enterprises (SMEs) are currently receiving top priority among policymakers of the South Asian Association for Regional Cooperation (SAARC) nations due to their great contribution to employment and GDP growth. This study examines the impact of financial literacy on the sustainable competitive performance of agro-based SMEs, with a focus on the mediating role of access to digital finance and the moderating role of business experience. Using Partial Least Squares Structural Equation Modelling (PLS-SEM), we analysed data from 345 SME owner-managers. The results indicate that financial literacy positively affects sustainable competitive performance, with access to digital finance serving as a significant mediator. However, business experience does not moderate the relationship between financial literacy and access to digital finance. These findings suggest that improving financial literacy and enhancing digital finance access are critical for the sustainable development of agro-based SMEs in the SAARC region. [ABSTRACT FROM AUTHOR]

In 2023, in an effort to revive the sluggish economy after the COVID-19 pandemic, the Chinese government implemented a variety of stimulus measures, such as interest rate cuts, tax cuts for small and medium-sized enterprises, and the issuance of local government bonds. But recovery has been challenging owing to export controls by the United States, lackluster domestic demand, high youth unemployment, and a real estate bubble. Externally, to respond to stronger cooperation between the United States and its allies in Western Europe and Asia, China actively pursued diplomatic activities with its traditional allies, such as Russia, and developing countries. [ABSTRACT FROM AUTHOR]

We expand the concept of epitaxy to a regime of “twisted epitaxy” with the epilayer crystal orientation between two substrates influenced by their relative orientation. We annealed nanometer-thick gold (Au) nanoparticles between two substrates of exfoliated hexagonal molybdenum disulfide (MoS2) with varying orientation of their basal planes with a mutual twist angle ranging from 0° to 60°. Transmission electron microscopy studies show that Au aligns midway between the top and bottom MoS2 when the twist angle of the bilayer is small (>~7°). For larger twist angles, Au has only a small misorientation with the bottom MoS2 that varies approximately sinusoidally with twist angle of the bilayer MoS2. Four-dimensional scanning transmission electron microscopy analysis further reveals a periodic strain variation (>|±0.5%|) in the Au nanodisks associated with the twisted epitaxy, consistent with the Moiré registry of the two MoS2 twisted layers. [ABSTRACT FROM AUTHOR]

The deconfined quantum critical point (DQCP) represents a paradigm shift in quantum matter studies, presenting a “beyond Landau” scenario for order-order transitions. Its experimental realization, however, has remained elusive. Using high-pressure 11B nuclear magnetic resonance measurements on the quantum magnet SrCu2(BO3)2, we here demonstrate a magnetic field– induced plaquette singlet to antiferromagnetic transition above 1.8 gigapascals at a notably low temperature, Tc ≃ 0.07 kelvin. First-order signatures of the transition weaken with increasing pressure, and we observe quantum critical scaling at the highest pressure, 2.4 gigapascals. Supported by model calculations, we suggest that these observations can be explained by a proximate DQCP inducing critical quantum fluctuations and emergent O(3) symmetry of the order parameters. Our findings offer a concrete experimental platform for investigation of the DQCP. [ABSTRACT FROM AUTHOR]

The mechanical performance of porous metal with assembly of pores mimicking typical crystalline structures is studied via atomistic simulation and finite element method. The pore lattices are made with the same orientation as the face-centered cubic (FCC) copper lattice. The compression is applied in the [001] direction. Under the same initial porosity and identical pore size, pores assembled in diamond array result in a superior stress response under compression. The sample with pores assembled in body-centered cubic array, whose surface-to-volume ratio is close to that of either FCC or hexagonally close-packed (HCP) array, has a yet much higher yield stress. However, the FCC- and HCP-structured nanoporous samples exhibit a greater hardening effect. The Lubarda model for critical stress to trigger dislocation emission is extended to the nanoporous geometry numerically. The magnitude and distribution of shear stress on the slip plane are found crucial to dislocation activities. No strong correlation between dislocation formation and early densification of nanoporous geometry is found. Through comparing the yielding and hardening behavior among differently structured nanoporous samples, new understanding could be established on their mechanical performance. Enhanced structural integrity could better support their diverse applications by design. [ABSTRACT FROM AUTHOR]

The growth of a nanovoid in single-crystal copper has been studied via molecular dynamics (MD) method. The objective is to build the correlation between material transport pattern and dislocation structures. MD results are examined by characterizing the material transport via the "relative displacement" of atoms, where the homogenous elastic deformation has been excluded. Through this novel approach, we are able to illustrate the feasibility of void growth induced by shear loops/curves. At a smaller scale, the formation and emission of shear loops/curves contribute to the local mass transport. At a larger scale, a new mechanism of void growth via frustum-like dislocation structure is revealed. A phenomenological description of void growth via frustum-like dislocation structure is also proposed. [ABSTRACT FROM AUTHOR]

Aiming at the thermal load problem of the four-stroke high-speed Diesel engine piston, a piston thermal fluid-solid coupling model based on the combustion thermal boundary and the two-phase flow oscillation cooling thermal boundary is established. The model considers the problem that the piston cannot fill the cooling cavity due to the reciprocating motion. The effects of different engine speeds and the injection speed on the filling rate are studied. The variation curves of the filling rate of the oil in the cooling cavity are simulated, and the transient heat transfer coefficient and temperature of each crank angle are obtained. The average value is then analyzed by thermal flow-solid coupling method, and the influence of the filling rate of the piston cavity on the temperature field of the piston is obtained. Through the comparison of the experimental results of the hardness plug measurement method, the calculation of the model is accurate and can be well used for the simulation of the piston temperature field and the evaluation of the thermal load at the critical position. Based on this model, the regularity analysis of the influencing factors of the piston thermal load is carried out. The influencing factors include the filling rate of the cavity, the air-fuel ratio, the injection timing, etc., and finally the engine operating range that meets the heat load requirements is obtained. [ABSTRACT FROM AUTHOR]

CAF-1 is an evolutionarily conserved H3/H4 histone chaperone that plays a key role in replication-coupled chromatin assembly and is targeted to the replication fork via interactions with PCNA, which, if disrupted, leads to epigenetic defects. In Saccharomyces cerevisiae, when the silent mating-type locus HMR contains point mutations within the E silencer, Sir protein association and silencing is lost. However, mutation of CDC7, encoding an S-phase-specific kinase, or subunits of the H4 K16-specific acetyltransferase complex SAS-I, restore silencing to this crippled HMR, HMRae**. Here, we observed that loss of Cac1p, the largest subunit of CAF-1, also restores silencing at HMRae**, and silencing in both cac1Δ and cdc7 mutants is suppressed by overexpression of SAS2. We demonstrate Cdc7p and Cac1p interact in vivo in S phase, but not in G1, consistent with observed cell cycle-dependent phosphorylation of Cac1p, and hypoacetylation of chromatin at H4 K16 in both cdc7 and cac1Δ mutants. Moreover, silencing at HMRae** is restored in cells expressing cac1p mutants lacking Cdc7p phosphorylation sites. We also discovered that cac1Δ and cdc7- 90 synthetically interact negatively in the presence of DNA damage, but that Cdc7p phosphorylation sites on Cac1p are not required for responses to DNA damage. Combined, our results support a model in which Cdc7p regulates replication-coupled histone modification via a CAC1-dependent mechanism involving H4 K16ac deposition, and thereby silencing, while CAF-1-dependent replicationand repair-coupled chromatin assembly per se are functional in the absence of phosphorylation of Cdc7p consensus sites on CAF-1. [ABSTRACT FROM AUTHOR]

Retromer is a peripheral membrane protein complex that coordinates multiple vesicular trafficking events within the endolysosomal system. Here, we demonstrate that retromer is required for the maintenance of normal lysosomal morphology and function. The knockout of retromer subunit Vps35 causes an ultrastructural alteration in lysosomal structure and aberrant lysosome function, leading to impaired autophagy. At the whole-cell level, knockout of retromer Vps35 subunit reduces lysosomal proteolytic capacity as a consequence of the improper processing of lysosomal hydrolases, which is dependent on the trafficking of the cation-independent mannose 6-phosphate receptor (CI-M6PR). Incorporation of CI-M6PR into endosome transport carriers via a retromer-dependent process is restricted to those tethered by GCC88 but not golgin-97 or golgin-245. Finally, we show that this retromer-dependent retrograde cargo trafficking pathway requires SNX3, but not other retromer-associated cargo binding proteins, such as SNX27 or SNX-BAR proteins. Therefore, retromer does contribute to the retrograde trafficking of CI-M6PR required for maturation of lysosomal hydrolases and lysosomal function. [ABSTRACT FROM AUTHOR]

To quantitatively evaluate and diagnose the carrying capacity of regional water resources under uncertain conditions, an index system and corresponding grade criteria were constructed from the perspective of carrying subsystem. Meanwhile, an improved entropy weight method was used to determine the objective weight of the index. Then, an evaluation model was built by applying set pair analysis, and a set pair potential based on subtraction was proposed to identify the carrying vulnerability factors. Finally, an empirical study was carried out in Anhui Province. The results showed that the consistency among objective weights of each index was considered, and the uncertainty between the index and grade criterion was reasonably dealt with. Furthermore, although the carrying situation in Anhui was severe, the development tended to be improved. The status in Southern Anhui was superior to that in the middle area, and that in the northern part was relatively grim. In addition, for Northern Anhui, the fewer water resources chiefly caused its long-term overloaded status. The improvement of capacity in the middle area was mainly hindered by its deficient ecological water consumption and limited water-saving irrigation area. Moreover, the long-term loadable condition in the southern part was due largely to its relatively abundant water resources and small population size. This evaluation and diagnosis method can be widely applied to carrying issues in other resources and environment fields. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the feasibility of using folate‑targeted superparamagnetic iron oxide nanoparticles (SPIO) as a magnetic resonance (MR) contrast agent that targets human tongue cancer cells. Folate‑targeted and folate‑free bilayer micelles composed of a diblock copolymer of polyethylene glycol (PEG) and poly‑caprolactone (PCL) that encapsulated SPIO in their hydrophobic core (SPIO‑PEG‑PCL micelles) were synthesized. The cytotoxicity of each set of micelles towards Tca‑8113 cells was examined using methyl thiazolyl tetrazolium (MTT) assays. Tca‑8113 cells were incubated with folate‑free SPIO‑PEG‑PCL micelles and folate‑targeted SPIO‑PEG‑PCL micelles at an Fe concentration of 80 μg/ml for 0.5, 1 and 2 h. MR imaging was subsequently performed and relative T2 relaxation time was recorded. Endocytosis of each micelle type was observed using Prussian blue staining. The MTT assays demonstrated that varying concentrations of folate‑targeted SPIO‑PEG‑PCL micelles did not result in statistically significant differences in Tca‑8113 cell viability when compared with folate‑free SPIO‑PEG‑PCL micelles (F=0.698; P=0.676). In the MR images obtained, decreased T2‑weighted signal intensity was observed for the folate‑targeted SPIO‑PEG‑PCL and folate‑free SPIO‑PEG‑PCL micelle treatments, particularly after the 2‑h incubation period. However, the folate‑targeted micelles exhibited a significantly greater decrease in signal intensity and a higher relative T2 relaxation time at each time point (P=0.002). In addition, blue intracellular particles were observed in the cells that were incubated with each type of micelle and stained with Prussian blue. However, a greater number of blue particles underwent endocytosis in the folate‑targeted group. Thus, folate‑targeted SPIO‑PEG‑PCL micelles exhibited preferential targeting of Tca‑8113 cells when compared with folate‑free SPIO‑PEG‑PCL micelles, and these results support the potential for these micelles to be used for the early diagnosis of tongue cancer. [ABSTRACT FROM AUTHOR]

PurposeAsignificant hurdle in developing reliable gene expression-based prognostic models has been the limited sample size, which can cause overfitting and false discovery. Combining data from multiple studies can enhance statistical power and reduce spurious findings, but how to address the biologic heterogeneity across different datasets remains a major challenge. Better meta-survival analysis approaches are needed. Material and Methods We presented a decentralized learning framework for meta-survival analysis without the need for data aggregation. Our method consisted of a series of proposals that together alleviated the influence of data heterogeneity and improved the performance of survival prediction. First, we transformed the gene expression profile of every sample into normalized percentile ranks to obtain platform-agnostic features. Second, we used Stouffer's meta-z approach in combination with Harrell's concordance index to prioritize and select genes to be included in the model. Third, we used survival discordance as a scale-independent model loss function. Instead of generating a merged dataset and training themodel therein, we avoided comparing patients across datasets and individually evaluated the loss function on each dataset. Finally, we optimized themodel by minimizing the joint loss function. Results Through comprehensive evaluation on 31 public microarray datasets containing 6,724 samples of several cancer types, we demonstrated that the proposed method has outperformed (1) single prognostic genes identified using conventional meta-analysis, (2) multigene signatures trained on single datasets, (3) multigene signatures trained on merged datasets as well as by other existing meta-analysis methods, and (4) clinically applicable, established multigene signatures. Conclusion The decentralized learning approach can be used to effectively perform meta-analysis of gene expression data and to develop robust multigene prognostic signatures. [ABSTRACT FROM AUTHOR]

Background: Conventional differential gene expression analysis by methods such as student's t-test, SAM, and Empirical Bayes often searches for statistically significant genes without considering the interactions among them. Network-based approaches provide a natural way to study these interactions and to investigate the rewiring interactions in disease versus control groups. In this paper, we apply weighted graphical LASSO (wgLASSO) algorithm to integrate a data-driven network model with prior biological knowledge (i.e., protein-protein interactions) for biological network inference. We propose a novel differentially weighted graphical LASSO (dwgLASSO) algorithm that builds group-specific networks and perform network-based differential gene expression analysis to select biomarker candidates by considering their topological differences between the groups. Results: Through simulation, we showed that wgLASSO can achieve better performance in building biologically relevant networks than purely data-driven models (e.g., neighbor selection, graphical LASSO), even when only a moderate level of information is available as prior biological knowledge. We evaluated the performance of dwgLASSO for survival time prediction using two microarray breast cancer datasets previously reported by Bild et al. and van de Vijver et al. Compared with the top 10 significant genes selected by conventional differential gene expression analysis method, the top 10 significant genes selected by dwgLASSO in the dataset from Bild et al. led to a significantly improved survival time prediction in the independent dataset from van de Vijver et al. Among the 10 genes selected by dwgLASSO, UBE2S, SALL2, XBP1 and KIAA0922 have been confirmed by literature survey to be highly relevant in breast cancer biomarker discovery study. Additionally, we tested dwgLASSO on TCGA RNA-seq data acquired from patients with hepatocellular carcinoma (HCC) on tumors samples and their corresponding non-tumorous liver tissues. Improved sensitivity, specificity and area under curve (AUC) were observed when comparing dwgLASSO with conventional differential gene expression analysis method. Conclusions: The proposed network-based differential gene expression analysis algorithm dwgLASSO can achieve better performance than conventional differential gene expression analysis methods by integrating information at both gene expression and network topology levels. The incorporation of prior biological knowledge can lead to the identification of biologically meaningful genes in cancer biomarker studies. [ABSTRACT FROM AUTHOR]

This study addresses overload and chaos in MOOC discussion forums by developing a model to categorize threads based on whether or not they are substantially related to course content. A linguistic model was built based on manually coded starting posts in threads from a statistics MOOC, and tested on the second offering of the course, another statistics MOOC, a psychology MOOC, a physiology MOOC, and a test set of reply posts. Results showed that content-related starting posts had distinct linguistic features that appeared unrelated to the domain. The model demonstrated good reliability for all starting posts in statistics and psychology as well as for reply posts (accuracy ranged from 0.80 to 0.85). Reliability for starting posts in physiology was lower but still provided reasonably good predictive ability (accuracy was 0.73). The classification modelwas useful across all time segments of the courses; the number of views and votes threads received were not helpful. [ABSTRACT FROM AUTHOR]

An accurate estimation of moisture in oil-impregnated cellulose of a transformer is difficult due to the complex moisture dynamics inside the transformer, which is highly influenced by the temperature and dimension of the transformer. In this study, a novel particle tracing method is proposed for estimating the moisture in transformers. Different from the conventional approaches using Fick's diffusion law, the proposed method formulates moisture diffusion from a microscopic view of water particles' motion. Especially, the transmission probability of water particles is employed to correlate the microscopic particles' motion with the macroscopic moisture distribution. The proposed particle tracing method is applied to model moisture dynamics in both pressboard specimens and a prototype transformer. Extensive moisture diffusion and ageing experiments are carried out to verify the proposed method. [ABSTRACT FROM AUTHOR]

Background: Multi-slice computed tomography enterography (MSCTE) is now widely used to diagnose and monitor intestinal disease. Preliminary studies suggest that MSCTE may be useful in detecting intestinal tuberculosis (ITB). We sought to assess the use of MSCTE for the diagnosis of ITB in our medical center.Methods: In this retrospective study, 15 patients (11 males and 4 females, 6 to 65 years old) were enrolled and diagnosed with ITB by MSCTE. Diagnosis were confirmed by pathology or clinical criteria. Two experienced abdominal radiologists evaluated the images and defined the location, number, shape, edge, surrounding tissue alterations of ITB and other associated changes in the peritoneum, mesentery and solid abdominal organs.Results: The interval between the onset of symptoms and diagnosis varied from 20 days to 10 years. The most common symptom was abdominal pain (80 %). The ileocecum was the most common site affected by ITB (87 %). Morphological MSCTE findings were variable and included multi-segmental symmetric intestinal mural thickening found in 6 patients (40 %), solid masses found in 9 patients (60 %), and enlarged lymph nodes (LNs) found in 13 (87 %) patients. Non-enhancing central necrosis and rim enhancement were noted in 10 patients (67 %).Conclusions: Characteristic MSCTE findings of ITB include solid mass or multi-segmental symmetric mural thickening involving the ileocecal area and rim enhanced LNs. Knowledge of these features in combination with a high index of suspicion can be useful in early diagnosis of ITB. [ABSTRACT FROM AUTHOR]

Zinc amide catalyzed, regioselective allenylation and propargylation of ketones with allenyl boronate is reported. Tertiary allenyl and homopropargyl alcohols were obtained, respectively, in high selectivities, from the same starting materials, simply by changing the reaction conditions. The substrate scope was wide. Mechanistic studies suggest that the reactions are controlled under kinetic and thermodynamic conditions. [ABSTRACT FROM AUTHOR]

Background: Subtelomeric regions dynamically change their epigenetic pattern during development and progression of several malignancies and degenerative disorders. However, DNA methylation of human subtelomeres and their correlation to telomere length (TL) remain undetermined in glioma. Results: Herein, we report on the selective changes in subtelomeric DNA methylation at the end of five chromosomes (Chr.) (7q, 8q. 18p, 21q, and XpYp) and ascertain their correlation with TL in patients with glioma. Subtelomeric methylation level was invariably higher in glioma patients compared to the control group, irrespective of their age and tumor grade. In particular, a significant increase in methylation was observed at the subtelomeric CpG sites of Chr. 8q, 21q, and XpYp in tissues, obtained from the brain tumor of glioma patients. In contrast, no significant change in methylation was observed at the subtelomere of Chr. 7q and 18p. Selective changes in the subtelomeric methylation level, however, did not show any significant correlation to the global TL. This observed phenomenon was validated in vitro by inducing demethylation in a glioblastoma cell line (SF-767) using 5-azacytidine (AZA) treatment. AZA treatment caused significant changes in the subtelomeric methylation pattern but did not alter the TL, which supports our hypothesis. Conclusions: DNA methylation level dramatically increased at the subtelomere of Chr.8q, 21q, and XpYp in malignant glioma, which could be used as an early epigenetic diagnostic biomarker of the disease. Alterations in subtelomeric methylation, however, have no effects on the TL. [ABSTRACT FROM AUTHOR]

Electron transfer into metal nanoparticles on oxide supports is associated with unusual morphological, electronic, and chemical properties of the charged system. Two fundamental charging routes have been identified so far, which are electron tunneling through ultrathin oxide films supported by a bulk metal and charge donation from single-ion impurities embedded in the oxide matrix. In this study, we have investigated whether both routes lead to the formation of metal deposits with identical properties. For this purpose, Au islands have been prepared on 1-2 ML thin MgO/Ag(001) layers and on 25-ML-thick CaO films doped with Mo impurities. The morphological and electronic properties of the islands were analyzed with low-temperature scanning tunneling microscopy (STM) and spectroscopy. In both systems, pronounced electron confinement effects are observed in the nanostructures, arising from the quantization of one and the same Au electronic band. Moreover, clear experimental signatures for a charge transfer into the islands are found, such as a layer-by-layer growth of the ad-metal and a negative contrast of the oxide region around the deposits in STM images. Our data provide evidence that the charged nanostructures exhibit comparable properties independent of the origin of the extra electrons. This agreement suggests that ultrathin oxide films may be used as model systems for doped bulk oxides, as used in heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

Background: This study aims to analyze the computed tomography (CT) and magnetic resonance imaging(MRI) characteristics of hepatic epithelioid hemangioendothelioma (HEHE). Methods: Eleven patients with histopathologically confirmed HEHE via surgical excision or biopsy were included. Imaging findings of these 11 patients were retrospectively analyzed (CT images obtained from all patients and MR images from five patients). Patterns of growth, characteristics of distribution, density/signal features, patterns of contrast enhancement, and changes of adjacent tissues were evaluated. Results: HEHE is characterized by multiple lesions in the liver. HEHE could be further categorized as three types when considering patterns of growth: nodular type(5 cases), coalescent type(1 case) and mixed type(5 cases). In this study, a total of 312 lesions were detected, 214(74.3 %) of which were subcapsular. All lesions appeared as hypodense while round lower density were found within 10 lesions(<2 cm) on unenhanced CT images. On MRI, all lesions demonstrated low signal intensity on T1 weighted images and high heterogeneous signal intensity on T2 weighted images when compared to the normal liver parenchyma. Other imaging features included "lollipop sign" (6 cases) and capsular retraction(6 cases). On contrast-enhanced CT and MRI, lesions smaller than 2.0 cm mostly showed mild homogeneous enhancement (214/227, 94.3 %); lesions measuring 2.0-3.0 cm in diameter showed ring-like enhancement (16/53,30.2 %) and heterogeneous delayed enhancement (29/53,54.7 %); lesions larger than 3.0 cm demonstrated heterogeneous delayed enhancement (26/32, 81.3 %). Conclusion: The imaging findings of HEHE showed some typical imaging features and size-dependent patterns with contrast enhancement on both CT and MR images, these features can be used for accurate imaging diagnosis of HEHE. [ABSTRACT FROM AUTHOR]

In this paper, we address the theoretical aspects of coherence region modeling and its inversion methods for polarimetric interferometric synthetic aperture radar (PolInSAR). Instead of only considering the geometrical shape of the coherence region, we focus on directly modeling the whitened interferometric cross-correlation matrix of the PolInSAR data. In particular, we consider three classes of generic scattering models that respectively contain single, double, and triple phase centers within one resolution cell. We then demonstrate, for each class, that the modeled whitened interferometric cross-correlation matrix is normal. Based on this property, we propose, for each case, efficient algorithms to obtain the best normal matrix approximation solution for model inversion from the observed whitened interferometric cross-correlation matrix. In addition, we show how a simple and effective criterion can be designed from the derived solutions for model validation. Finally, we verify the solutions with both simulated and real data. The results prove the proposed method to be a very promising tool for PolInSAR applications. [ABSTRACT FROM PUBLISHER]

The electronic structure of CaO films of 10-60 monolayer thickness grown on Mo(001) has been investigated with synchrotron-mediated x-ray photoelectron spectroscopy (XPS) and scanning tunneling microscopy (STM). Upon annealing or reducing the thickness of the film, a rigid shift of the CaO bands to lower energy is revealed. This evolution is explained with a temperature-induced diffusion of Mo ions from the metal substrate to the oxide and their accumulation in the interface region of the film. The Mo substitutes divalent Ca species in the rocksalt lattice and is able to release electrons to the system. The subsequent changes in the Mo oxidation state have been followed with high-resolution XPS measurements. While near-interface Mo transfers extra electrons back to the substrate, generating an interface dipole that gives rise to the observed band shift, near-surface species are able to exchange electrons with adsorbates bound to the oxide surface. For example, exposure of O2 results in the formation of superoxo species on the oxide surface, as revealed from STM measurements. Mo interdiffusion is therefore responsible for the pronounced donor character of the initially inert oxide, and largely modifies its adsorption and reactivity behavior. [ABSTRACT FROM AUTHOR]

Scanning tunneling microscopy has developed into a powerful tool for the characterization of conductive surfaces, for which the overlap of tip and sample wave functions determines the image contrast. On insulating layers, as the CaO thin film grown on Mo(001) investigated here, direct overlap between initial and final states is not enabled anymore and electrons are transported via hopping through the conductionband states of the oxide. Carrier transport is accompanied by strong phonon excitations in this case, imprinting an oscillatory signature on the differential conductance spectra of the system. The phonons show a characteristic spatial dependence and become softer around lathee irregularities in the oxide film, such as dislocation lines. [ABSTRACT FROM AUTHOR]

A novel fluorescence method for the determination of guanine was developed based on the fluorescence enhancement of Cu2+-nuclear fast red complex in the presence of guanine in Tris-HCl buffer. The complex of Cu2+ with nuclear fast red resulted in a dramatic quenching of the fluorescence intensity. Nuclear fast red were dissociated from the complex with the addition of guanine due to the strong interaction between guanine and Cu2+, which caused the fluorescence enhancement. The enhanced fluorescence intensity was well proportional to the concentration of guanine in the range of 4.96 x 10-8-1.09 x 10-6 mol/L with the limit of detection 1.9 x 10-8 mol/L. The method has been applied successfully to the determination of guanine in serum and DNA samples, and the recoveries were from 96.0% to 104.8%. [ABSTRACT FROM AUTHOR]

The 8-week-old SPF class C57BL/6 male mice were used as experimental object, the compound diphenoxylate was adopted to establish the constipation model. At the same time, three groups were established maren pills positive control group, blank control group and rice isomalto-oligosaccharide low, medium, and high dose groups. The body weight change of experimental mice gavage before and after, the mice first defecation time, 8 h defecation number, 8 h defecation quality, 8 h defecation moisture content and small intestine propulsion rate were analyzed through single factor experiment. The results showed that there were significant differences between the constipation model group and positive control group, blank control group. Constipation model group was established successfully; rice isomalto-oligosaccharide could shorten the mice first defecation time, improve 8 h defecation quality, 8 h defecation moisture content and small intestine propulsion rate, and the aperient bowel effect of medium dose group was better. [ABSTRACT FROM AUTHOR]

To maintain body temperature, sweat glands develop from embryonic ectoderm by a poorly defined mechanism.We demonstrate a temporal cascade of regulation during mouse sweat gland formation. Sweat gland induction failed completely when canonical Wnt signaling was blocked in skin epithelium, and was accompanied by sharp downregulation of downstreamWnt, Eda and Shh pathway genes. The Wnt antagonist Dkk4 appeared to inhibit this induction: Dkk4 was sharply downregulated in β-catenin-ablated mice, indicating that it is induced by Wnt/β-catenin; however, its overexpression repressed Wnt target genes and significantly reduced gland numbers. Eda signaling succeededWnt.Wnt signalingwas still active and nascent sweat gland pre-germs were still seen in Eda-null mice, but the pre-germs failed to develop further and the downstream Shh pathway was not activated. When Wnt and Eda were intact but Shh was ablated, germ induction and subsequent duct formation occurred normally, but the final stage of secretory coil formation failed. Thus, sweat gland development shows a relay of regulatory steps initiated by Wnt/β-catenin- itself modulated by Dkk4-with subsequent participation of Eda and Shh pathways. [ABSTRACT FROM AUTHOR]

House dust samples containing 25-738 mg of Pb kg-1 from 15 cities in China were assessed for in vitro Pb bio-accessibility and in vivo Pb relative bioavailability. On the basis of stable Pb isotope ratios, the Pb in dust samples mainly originated from coal combustion. Lead bio-accessibility was determined using gastric (GP) and intestinal phase (IP) of solubility bioaccessibility research consortium (SBRC), in vitro gastrointestinal (IVG), Deutsches Institut für Normunge.V. (DIN), and physiologically based extraction test methods (PBET), while Pb relative bioavailability (RBA) was determined using a mouse blood model. Lead bioaccessibility in 24 house dust samples varied significantly (23-99%) depending on the methods. Values from the IP were considerably lower than those from the GP because of the co-precipitation of Pb with iron and readsorption onto the dust matrix. The SBRC assay with lower GP pH produced higher Pb bioaccessibility because of enhanced Pb dissolution. When compared to mouse blood data using 12 dust samples (29-60%), SBRC- GP and DIN-GP data were correlated with Pb RBA with r2 values of 0.68 and 0.85 and intercepts 3.15 and 17.4, respectively. Overall, SBRC-GP had potential to predict Pb RBA in dust samples. However, our data suggested that more research is needed to develop a valid in vitro method for predicting Pb RBA in house dust. [ABSTRACT FROM AUTHOR]

High-performance photovoltaic cells use semiconductors to convert sunlight into clean electrical power, and transparent dielectrics or conductive oxides as antireflection coatings. A common feature of these materials is their high refractive index. Whereas high-index materials in a planar form tend to produce a strong, undesired reflection of sunlight, high-index nanostructures afford new ways to manipulate light at a subwavelength scale. For example, nanoscale wires, particles and voids support strong optical resonances that can enhance and effectively control light absorption and scattering processes. As such, they provide ideal building blocks for novel, broadband antireflection coatings, light-trapping layers and super-absorbing films. This Review discusses some of the recent developments in the design and implementation of such photonic elements in thin- film photovoltaic cells. [ABSTRACT FROM AUTHOR]

In this paper, a general scheme for complete model-based decomposition of the polarimetric synthetic aperture radar (POLSAR) coherency matrix data is presented. We show that the POLSAR coherency matrix can be completely decomposed into three components contributed by volume scattering and two single scatterers (characterized by rank-1 matrices). Under this scheme, solving for the volume scattering power amounts to a generalized eigendecomposition problem, and the nonnegative power constraint uniquely determines the minimum eigenvalue as the volume scattering power. Furthermore, in order to discriminate the remaining components, we propose two approaches. One is based on eigendecomposition, and the other is based on model fitting, both of which are shown to properly resolve the surface and double-bounce scattering ambiguity. As a result, this paper in particular contributes to two pending needs for model-based POLSAR decomposition. First, it overcomes negative power problems, i.e., all the decomposed powers are strictly guaranteed to be nonnegative; and second, the three-component decomposition exactly accounts for every element of the observed coherency matrix, leading to a complete utilization of the fully polarimetric information. [ABSTRACT FROM PUBLISHER]

Purpose: To study the prevalence of non-detectable chromosomal abnormalities by quantitative fluorescent polymerase chain reaction (QF-PCR) in a Chinese population referred for amniocentesis. Methods: The karyotype results were reviewed in 8,466 amniotic fluid cultures performed for positive fetal Down syndrome screening or advanced maternal age between January 2002 and June 2012. The karyotype results were classified as detectable or not detectable by QF-PCR, using the assumption that all tests were conducted by this rapid molecular method. Results: Of the 8,466 karyotypes obtained, 211 abnormal karyotypes were found (2.5 %). Out of these, 168 cases of common aneuploidies were identified by QF-PCR, and 43 cases of chromosomal abnormalities were missed. The 43 cases missed by QF-PCR included 31 cases predicted to confer no increased risk and 12 with a potential clinical significance. When QF-PCR shows a normal result, the overall residual risk is 0.1 % for any clinically significant chromosomal abnormality. Conclusions: A normal QF-PCR result predicts a very low residual risk for patients who are referred solely for an increased risk of a common trisomy. [ABSTRACT FROM AUTHOR]

Recent experiments have demonstrated that tiny amounts of Mo impurities give rise to drastic changes in the adsorption characteristic of a wide-gap CaO(001) film. In this scanning tunneling microscopy (STM) and density functional theory paper, we elucidate the underlying mechanism by analyzing the energy levels of the Mo dopants as a function of their oxidation state and depth below the surface. We show that Mo2+ ions in CaO subsurface layers can be reversibly charged and discharged by inducing local band-bending effects with the STM tip. A similar charge switching is not possible for Mo species in a higher oxidation state, as their highest-occupied molecular orbitals are located well below the onset of the CaO conduction band. The easiness of charge switching in Mo2+ ions explains the remarkable chemical properties of doped CaO films, as it renders the material a strong electron donor to adsorbates bound to the oxide surface. [ABSTRACT FROM AUTHOR]

Silicon is viewed as an excellent electrode material for lithium batteries due to its high lithium storage capacity. Various Si nanostructures, such as Si nanowires, have performed well as lithium battery anodes and have opened up exciting opportunities for the use of Si in energy storage devices. The mechanism of lithium insertion and the interaction between Li and the Si electrode must be understood at the atomic level; this understanding can be achieved by first-principles simulation. Here, first-principles computations of lithiation in silicon electrodes are reviewed. The review focuses on three aspects: the various properties of bulk Li-Si compounds with different Li concentrations, the electronic structure of Si nanowires and Li insertion behavior in Si nanowires, and the dynamic lithiation process at the Li/Si interface. Potential study directions in this research field and difficulties that the field still faces are discussed at the end. [ABSTRACT FROM AUTHOR]

The increasingly stringent NOx emission regulations of the International Marine Organization (IMO) have demanded new design concepts and architectures for diesel engines. The Miller cycle, which reduces the in-cylinder combustion temperature by reducing the effective compression ratio, is the principal measure used for reducing NOx specific emissions; however, this is at the cost of volumetric efficiency and engine power. Therefore, it is essential to combine the Miller cycle with a highly boosted turbocharging system, two-stage turbocharging for example, to recover the power. While much work has been done in the development of Miller-cycle regulatable two stage turbocharging system for marine diesel engines, there are nonetheless few, if any, thorough discussions on system optimization and performance comparison. This study presents a theoretical optimization design process for a Miller-cycle regulatable, two-stage turbocharging system for marine diesel engines. First, the different scenarios and regulation methods of two-stage turbocharging systems are compared according to the system efficiency and equivalent turbine flow characteristics. Then, a multizone combustion model based on a one-dimensional cycle simulation model is established and used for the optimization of valve timings according to the IMO NOx emission limits and fuel efficiencies. The high- and low-stage turbochargers are selected by an iterative matching method. Then, the control strategies for the boost air and high-stage turbine bypass valves are also studied. As an example, a Miller-cycle regulatable, two-stage turbocharging system is designed for a highly boosted high-speed marine diesel engine. The results show that NOx emissions can be reduced by 30% and brake specific fuel consumption (BSFC) can also be improved by a moderate Miller cycle combined with regulatable two-stage turbocharging. [ABSTRACT FROM AUTHOR]

Background: The emerging concept is that microRNAs (miRNAs) play a central role in controlling stem cell self-renewal and fate determination by regulating the expression of stem cell regulators. miR-125b, one of neuronal miRNAs, recently was found to be necessary for neural differentiation of neural stem/progenitor cells (NS/PCs). However, the other specific biological role of miR-125b in NS/PCs is little known. We used rat NS/PCs as a model system to study the role of miR-125b in governing the behavior of NS/PCs. Results: We report here the transfection of exogenous miR-125b inhibited proliferation of NS/PCs but promoted differentiation and migration. Whereas anti-miR-125b had the opposite effect. Similar results were observed when Nestin was knocked down by siRNA. Subsequently, we demonstrated that Nestin was a direct functional target of miR-125b. MiR-125b downregulates the expression of luciferase through Nestin 3'untranslated region (3'-UTR), and the regulation was abolished by mutations in the miR-125b binding site. MiR-125b targeted the 3'-UTR of Nestin and reduced the abundance of Nestin at both mRNA and protein levels. Conclusion: The results provided new insight into the function by which miR-125b modulates NS/PCs proliferation, differentiation and migration. The data also indicated the regulatory role of miR-125b in NS/PCs might through the suppression of Nestin expression. [ABSTRACT FROM AUTHOR]

Background: Primary duodenal cancer (PDC) is rare and few studies have addressed it adequately, especially in China. The present study is to evaluate the clinicopathological features and prognosis of PDC in Chinese patients. Patients and methods: All the consecutive cases confirmed as PDC by histopathological analysis in The First Affiliated Hospital of Sun Yat-sen University between 1995 and 2008 were included. Clinicopathological details were retrospectively analysed and prognostic factors influencing survival were evaluated. Results: The patient cohort included 53 men and 38 women, accounting for only 0.02% of all in-patients during this period. Esophagogastroduodenoscopy and gastrointestinal barium radiography were mainstay diagnostic tests for PDC; they detected 88.6% and 83.3% of the tumours, respectively. Tumours mainly occurred in the descending portion of the duodenum (67.0%). Abdominal pain was the most frequent symptom (56.0%). Histologically, adenocarcinoma was the most common type (74.7%). The overall 1-, 3- and 5-year survival rates were 62.6%, 43.7% and 33.1%, respectively. Patients survived longer in the curative surgery group (median survival time of 45 months) than those in the palliative group (6 months) ( P < 0.001). Nodal metastasis and positive resection margin had a significant negative impact on survival in patients undergoing potentially curative surgery in a univariate and multivariate model ( P < 0.05). Conclusion: Patients with PDC are rare and lack specific presentations. Esophagogastroduodenoscopy and gastrointestinal barium radiography are effective in screening this rare tumour. Nodal metastasis and positive resection margins are associated with a poor prognosis. A curative surgery that achieves complete resection with negative margin should be pursued. [ABSTRACT FROM AUTHOR]

An improved three-component decomposition for polarimetric synthetic aperture radar (SAR) data is proposed in this paper. The reasons for the emergence of negative powers in the Freeman decomposition have been analyzed, and three corresponding improvements are included in the proposed method. First, the deorientation process is applied to the coherency matrix before it is decomposed into three scattering components. Then, the coherency matrix with the maximal polarimetric entropy, i.e., the unitmatrix, is used as the new volume-scattering model instead of the original one adopted in the Freeman decomposition. A power constraint is also added to the proposed three-component decomposition. The E-SAR polarimetric data acquired over the Oberpfaffenhofen area in Germany are applied in the experiment. The results show that the pixels with negative powers are totally eliminated by the proposed decomposition, demonstrating the effectiveness of the new model. [ABSTRACT FROM AUTHOR]

Objectives: Ingestion of a foreign body (FB) is a common occurrence; however, few studies have reported its characteristics and endoscopic management in South China. The aim of this study is to investigate the clinical features of FB ingestion in South China and report its management through endoscopy.Methods: Data were collected from all consecutive patients with suspected FB ingestion accepting endoscopic management in our endoscopy center during the past 10 years. The demographic data, clinical presentations, and endoscopic management were reviewed and analyzed retrospectively.Results: A total of 561 patients with suspected FB ingestion underwent endoscopic management. Among them, 447 FBs were found in 439 (78.3%) patients. Fish bone ingestion was most common (60.4%). Most of the FBs were located in the esophagus (84.5%). The majority of patients (96.1%) were successfully treated with flexible endoscopy with the addition of suitable devices without any serious procedure-related complications. There was a significant difference in the types of FBs between the former and latter 5 years (P < 0.05), and fish bone ingestion became more prevalent with time. Compared with the conventional methods, a new technique with a reworked transparent cap was successful in dealing with small sharp FBs impacted at the entrance of esophagus. The new technique had a shorter operation time (11.7 versus 17.9 min, P = 0.02) and an increased success rate (by 8%).Conclusions: In South China, fish bone is the most common FB found in the upper gastrointestinal tract. Endoscopic management is a safe and effective approach in managing FBs. A new technique with reworked transparent cap is useful and promising, but further study is needed for confirmation. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To investigate the prevalence of Barrett's esophagus (BE) and its risk factors in patients undergoing endoscopy for upper gastrointestinal symptoms in a Chinese tertiary referral medical center. METHODS: All consecutive patients receiving an endoscopy for upper gastrointestinal symptoms in our medical center from September to December 2007 were recruited. BE was explored for at endoscopy when a suspected columnar-lined esophagus was found. Patients with specialized intestinal metaplasia in the distal esophagus were defined as having BE. RESULTS: A total of 2022 patients (1053 male and 969 female) were recruited. The patients were aged 18 to 88 years and with a mean age of 46.97 ± 14.84 years. BE was found in 21 patients (15 male and 6 female), a prevalence of 1.0% of all patients receiving endoscopy for upper gastrointestinal symptoms in our medical center. One of the 21 patients had low-grade dysplasia. By logistic multivariate analysis, age ( OR 1.03; 95% CI, 1.00, 1.07) and reflux esophagitis ( OR 4.44; 95% CI, 1.22, 16.17) were factors associated significantly with BE. CONCLUSION: The prevalence of BE in our study was lower than that reported in other studies, especially in studies from developed countries. Older age and reflux esophagitis may be the risk factors for developing BE. [ABSTRACT FROM AUTHOR]

The mouse hair coat comprises protective ''primary'' and thermo-regulatory ''secondary'' hairs. Primary hair formation is ectodysplasin (Eda) dependent, but it has been puzzling that Tabby (Eda-/y) mice still make secondary hair. We report that Dickkopf 4 (Dkk4), a Wnt antagonist, affects an auxiliary pathway for Eda-independent development of secondary hair. A Dkk4 transgene in wild-type mice had no effect on primary hair, but secondary hairs were severely malformed. Dkk4 action on secondary hair was further demonstrated when the transgene was introduced into Tabby mice: the usual secondary follicle induction was completely blocked. The Dkk4-regulated secondary hair pathway, like the Eda-dependent primary hair pathway, is further mediated by selective activation of Shh. The results thus reveal two complex molecular pathways that distinctly regulate subtype-based morphogenesis of hair follicles, and provide a resolution for the longstanding puzzle of hair formation in Tabby mice lacking Eda. [ABSTRACT FROM AUTHOR]

In order to improve fuel efficiency and power density, the boost pressure of diesel engine is increasing continuously. The increase in boost level leads to some problems, such as lack of air under part load operating conditions, response delay during transient processes, and high mechanical and thermal load. In order to meet the high boost level demand, a new type of turbocharging system-mixed pulse converter (MIXPC) turbo-charging system for multicylinder diesel engines (from 4 to 20 cylinders) has been invented. A turbocharged diesel engine simulation model, based on one-dimensional finite volume method (FVM) and total variation diminishing (TVD) scheme, has been developed and used to design and analyze the MIXPC turbocharging system. The applications of MIXPC system in in-line 8- and 4-cylinder and V-type 16-cylinder medium-speed marine diesel engines have been studied by calculation and experiments. The results show that the invented MIXPC system has superior engine fuel efficiency and thermal load compared with original turbocharging systems. [ABSTRACT FROM AUTHOR]

A well-defined fluorescent conjugated polyfluorene with pendant lactopyranosyl ligands was easily prepared through Cu(I)-catalyzed azide/alkyne “click” ligation and Suzuki coupling polymerization. As a fluorescent multivalent model system of glycoconjugates, the polymer was first used for studies of metal ion-mediated carbohydrate−carbohydrate interaction based on fluorescence spectroscopy. A significant fluorescence quenching of the lactosyl-bearing polyfluorene was observed upon addition of calcium ion, which is attributed to the polymer aggregation derived from Ca2+-mediated complex formation. Dynamic light scattering can also prove Ca2+-induced aggregation of the polymer based on determination of the corresponding hydrodynamic diameters. The calcium-mediated lactose−lactose interaction was reversible when treated with EDTA. In control studies, Ca2+-induced fluorescence quenching can not be observed for cellobiosyl- or galactosyl-functionalized polymer analogues, which show that specific sugar structures are critical for carbohydrate−metal complex formation. [ABSTRACT FROM AUTHOR]

A concise and modular approach to synthesize a new type of cyclopentene-based diaminocyclitol library from d-serine and l-serine has been developed, and key steps in this synthesis are an aza-Claisen rearrangement, a ring-closing metathesis, and a Baylis−Hillman reaction. The developed chemistry may offer a unique way to investigate the neuraminidase (NA) mutation by systematically mapping the changes within its binding sites. [ABSTRACT FROM AUTHOR]

The unusual regioselectivity in the Diels−Alder reactions of pyranoquinone 1with (4,4-dimethoxybuta-1,3-dien-2-yloxy)trimethylsilane 2are explored by both computations and experiments. The regioselectivity is controlled by the electrostatic interaction of the lactone ring-oxygen and the vicinal quinone oxygen on the transition structure, which can be tuned by the terminal methyl group of the butadienes. [ABSTRACT FROM AUTHOR]

Some changes on the disease pattern of colorectal cancer (CRC) have occurred in some Asian countries recently. However, nothing is known about it in China lately. The present study is to determine whether there are any changes on the disease pattern of CRC in Southern China. Data were collected from all consecutive patients accepting colonoscopy in our endoscopy center during the last 20 years. The sociodemographic data, clinical presentations, endoscopic descriptions, and histological subtypes of patients confirmed as CRC by pathology were analyzed retrospectively. A total of 37,578 patients accepted colonoscopy from 1987 to 2006, in which 2,876 patients were diagnosed as CRC. The median age of patients in the 2nd decade (1997–2006; 62 years) was getting older than the 1st decade (1987–1996; 58 years; P = 0.043). Hematochezia was the most frequent symptom (55.8%), while rectum was the most common site distribution of CRC (51.0%). The incidence of right-sided colonic cancers in the 2nd decade (21.0%) was higher than the 1st decade (17.3%; P = 0.0314). Histologically, adenocarcinoma was the most common (92.4%), of which moderately differentiated tumors were more frequent (67.7%). CRCs with high-grade malignancy were more likely to occur in the 1st decade ( P < 0.0001). Rectum remains the most common site of CRC in southern China. But a rightward shift in the site distribution has occurred and patients are getting older. Tumors with high-grade malignancy have the tendency to decrease. [ABSTRACT FROM AUTHOR]

EDA signaling is important in skin appendage initiation. Its possible involvement in appendage subtype determination and postinduction stage appendage development, however, has not been studied systematically. To address these issues we manipulated Eda-A1 transgene expression in a tetracycline-regulated conditional mouse model, where the transgene is the only source of active ectodysplasin (Eda). We find that Eda-A1 restores sweat glands and all hair subtypes in Tabby, but each requires its action at an idiosyncratic time of development: by E17 for guard, by E19 for awl, and starting at E18 for zigzag/auchen hair. Guard and awl hairs were indistinguishable from their wild-type counterparts; but restored zigzag and auchen hairs, although recognizable, were somewhat smaller and lacked characteristic bends. Notably, secondary hair follicle formation of awl, auchen, and zigzag hairs required higher Eda-A1 expression level than did guard hair or sweat glands. Furthermore, Eda-A1 expression is required until the early dermal papilla stage for guard hair germs to make follicles, but is dispensable for their maturation. Similarly, sweat gland pegs require Eda-A1 at an early stage to form mature glands. Thus we infer that EDA signaling is needed for the determination and development of various skin appendages at spatiotemporally restricted intervals.Journal of Investigative Dermatology (2009) 129, 984–993; doi:10.1038/jid.2008.318; published online 16 October 2008 [ABSTRACT FROM AUTHOR]