112 research outputs found
Enhanced energy density with a wide thermal stability in epitaxial Pb0.92La0.08Zr0.52Ti0.48O3 thin films
High-quality epitaxial Pb0.92La0.08Zr0.52Ti0.48O3 (PLZT) films of thickness of 880 nm were fabricated using pulsed laser deposition on (001) Nb doped SrTiO3 (Nb:STO) substrates. Besides a confirmation of the epitaxial relationship [100]PLZT//[100]Nb:STO and (001)PLZT//(001)Nb:STO using X-ray diffraction, a transmission electron microscopy study has revealed a columnar structure across the film thickness. The recoverable energy density (Wrec) of the epitaxial PLZT thin film
capacitors increases linearly with the applied electric field and the best value of 31 J/cm3 observed at 2.27 MV/cm is considerably higher by 41% than that of the polycrystalline PLZT film of a comparable thickness. In addition to the high Wrec value, an excellent thermal stability as illustrated in a negligible temperature dependence of the Wrec in the temperature range from room temperature to 180 C is achieved. The enhanced Wrec and the thermal stability are attributed to the reduced defects and grain boundaries in epitaxial PLZT thin films, making them promising for energy storage applications that require both high energy density, power density, and wide operation temperatures
Centroacinar cells are progenitors that contribute to endocrine pancreas regeneration
Diabetes is associated with a paucity of insulin-producing β-cells. With the goal of finding therapeutic routes to treat diabetes, we aim to find molecular and cellular mechanisms involved in β-cell neogenesis and regeneration. To facilitate discovery of such mechanisms, we use a vertebrate organism where pancreatic cells readily regenerate. The larval zebrafish pancreas contains Notch-responsive progenitors that during development give rise to adult ductal, endocrine, and centroacinar cells (CACs). Adult CACs are also Notch responsive and are morphologically similar to their larval predecessors. To test our hypothesis that adult CACs are also progenitors, we took two complementary approaches: 1) We established the transcriptome for adult CACs. Using gene ontology, transgenic lines, and in situ hybridization, we found that the CAC transcriptome is enriched for progenitor markers. 2) Using lineage tracing, we demonstrated that CACs do form new endocrine cells after β-cell ablation or partial pancreatectomy. We concluded that CACs and their larval predecessors are the same cell type and represent an opportune model to study both β-cell neogenesis and β-cell regeneration. Furthermore, we show that in cftr loss-of-function mutants, there is a deficiency of larval CACs, providing a possible explanation for pancreatic complications associated with cystic fibrosis
Total Cerebral Small Vessel Disease Score and Cerebral Bleeding Risk in Patients With Acute Stroke Treated With Intravenous Thrombolysis
OBJECTIVE:
The aim of this study was to investigate the association of total cerebral small vessel disease (cSVD) score with the risk of intracerebral hemorrhage (ICH) in patients with acute ischemic stroke who received intravenous thrombolysis (IVT) using recombinant tissue-plasminogen activator (rt-PA).
METHODS:
We retrospectively reviewed clinical data from two stroke registries of patients with acute ischemic stroke treated with IVT. We assessed the baseline magnetic resonance (MR) visible cSVD markers and total cSVD score (ranging from 0 to 4) between patients with and without ICH after IVT. Logistic regression analysis was used to determine the association of total cSVD score with the risk of ICH after IVT, adjusted for cofounders selected by least absolute shrinkage and selection operator (LASSO). We additionally performed an E-value analysis to fully explain away a specific exposure-outcome association. Receiver operating characteristic (ROC) curve analysis was used to quantify the predictive potential of the total cSVD score for any ICH after IVT.
RESULTS:
Among 271 eligible patients, 55 (20.3%) patients experienced any ICH, 16 (5.9%) patients experienced a symptomatic ICH (sICH), and 5 (1.85%) patients had remote intracranial parenchymal hemorrhage (rPH). Logistic regression analysis showed that the risk of any ICH increased with increasing cSVD score [per unit increase, adjusted odds ratio (OR) 2.03, 95% CI 1.22â3.41, P = 0.007]. Sensitivity analyses using E-value revealed that it would need moderately robust unobserved confounding to render the exposure-outcome (cSVD-any ICH) association null. ROC analysis showed that compared with the National Institutes of Health Stroke Scale (NIHSS) score alone, a combination of cSVD and NIHSS score had a larger area under the curve for any ICH (0.811, 95% CI 0.756â0.866 vs. 0.784, 95% CI 0.723â0.846, P = 0.0004).
CONCLUSION:
The total cSVD score is associated with an increased risk of any ICH after IVT and improves prediction for any ICH compared with NIHSS alone
Mobile Health (mHealth) technology for improved screening, patient involvement and optimising integrated care in atrial fibrillation: The mAFA (mAF-App) II randomised trial
Whole exome sequencing identifies frequent somatic mutations in cell-cell adhesion genes in chinese patients with lung squamous cell carcinoma
Lung squamous cell carcinoma (SQCC) accounts for about 30% of all lung cancer cases. Understanding of mutational landscape for this subtype of lung cancer in Chinese patients is currently limited. We performed whole exome sequencing in samples from 100 patients with lung SQCCs to search for somatic mutations and the subsequent target capture sequencing in another 98 samples for validation. We identified 20 significantly mutated genes, including TP53, CDH10, NFE2L2 and PTEN. Pathways with frequently mutated genes included those of cell-cell adhesion/Wnt/Hippo in 76%, oxidative stress response in 21%, and phosphatidylinositol-3-OH kinase in 36% of the tested tumor samples. Mutations of Chromatin regulatory factor genes were identified at a lower frequency. In functional assays, we observed that knockdown of CDH10 promoted cell proliferation, soft-agar colony formation, cell migration and cell invasion, and overexpression of CDH10 inhibited cell proliferation. This mutational landscape of lung SQCC in Chinese patients improves our current understanding of lung carcinogenesis, early diagnosis and personalized therapy
Superstition and "lucky" apartments: Evidence from transaction-level
Using a sample of apartment transactions during 2004â2006 in Chengdu, China, we investigate the impact of superstitions in the Chinese real estate market. Numerology forms an important component of Chinese superstitious lore, with the numbers 8 and 6 signifying good luck, and the number 4 bad luck. We find that secondhand apartments located on floors ending with "8" fetch, on average, a 235 RMB higher price (per square meter) than on other floors. For newly constructed apartments, this price premium disappears due to uniform pricing of new housing units, but apartments on floors ending in an "8" are sold, on average, 6.9 days faster than on other floors. Buyers who have a phone number containing more "8"âs are more likely to purchase apartments in a floor ending with "8"; this suggests that at least part of the price premium for âluckyâ apartments arises from the buyersâ superstitious beliefs
A Novel Evaluation Method of Construction Homogeneity for Asphalt Pavement Based on the Characteristic of Component Distribution
To effectively evaluate the construction homogeneity of asphalt pavement, the tomography image of a core sample of asphalt pavement was obtained via industrial computed tomography (CT) equipment. According to the characteristics of CT images, an improved separation algorithm based on annular partition and Nobuyuki Otsu (OTSU) threshold segmentation was proposed. Based on the distribution of aggregates, voids and asphalt mortar, and the area ratio of each part in the CT images inside the pavement, a novel evaluation method for the distribution homogeneity of asphalt pavement components was put forward, and the validity of the evaluation index was also verified. The results show that the aggregates, voids and asphalt mortar in CT images can be effectively segmented by annular partition combined with the OTSU threshold separation algorithm. By superimposing the segmented image on the original image, the segmentation and identification effects of aggregates, voids and asphalt mortar in the CT image are confirmed. Compared with a non-segregated specimen, the average values of the horizontal heterogeneity coefficients of high, medium, light and fine-aggregate-segregated mixtures increased by 72.0%, 48.3%, 34.7% and 16.1%, respectively, where the change range is in accordance with the segregation degrees of several mixtures. The indirect tensile strength of fine-aggregate-, light-, medium- and high-segregated asphalt mixtures decreased by 8.3%, 16.7%, 25.0% and 45.8%, respectively, when compared with the non-segregated asphalt mixture. The index of the vertical heterogeneity coefficient has good correlation with the indirect tensile strength of segregated asphalt mixtures. The construction quality homogeneity of asphalt pavement in different regions can be reliably evaluated by the horizontal heterogeneity coefficient and vertical heterogeneity coefficient
Synthesis of penta-fold twinned Pd-Au-Pd segmental nanorods for in situ monitoring catalytic reaction
Multimetallic nanomaterials have many applications. The controlled synthesis of multimetallic nanomaterials is highly desired. We report a study on using penta-fold twinned (PFT) Au nanorods (NRs) as seeds to synthesize PFT Pd-Au-Pd segmental NRs. The results show that the different crystal structures of seeds, Iâ and cetyltrimethylammonium bromide (CTAB) significantly affect the deposition of Pd on seeds surface. The PFT Pd-Au-Pd segmental NRs showed excellent surface-enhanced Raman scattering (SERS) performance and improved catalytic activity. Our research is of great significance for the synthesis of similar nanostructures, and we also shown that PFT Pd-Au-Pd segmental NRs might have potential applications in studying the process of organic reaction
Plasma-engineered bifunctional cobalt-metal organic framework derivatives for high-performance complete water electrolysis
Metalâorganic framework (MOF) derivatives are among the most promising catalysts for the hydrogen evolution reaction (HER) for clean hydrogen energy production. Herein, we report the in situ synthesized MOF-derived CoPO hollow polyhedron nanostructures by simultaneous high temperature annealing and ArâN2 radio frequency plasma treatment in the presence of a P precursor and subsequent oxygen incorporation from open air at lower temperature. The optimum ArâN2 gas flow rates are used to precisely tune the P/O ratio, cut Co bonds within the MOFs and reconnect Co with P. Consequently, both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance are enhanced. Meanwhile, the filling of P elements can effectively change the electronic structure around the catalyst to ensure the uniform distribution of catalytically active sites. The resultant CoPO hollow nanocages with large specific surface areas show excellent bifunctional electrocatalytic activity towards both HER and OER with a low overpotential of 105 and 275 mV and a small Tafel slope of 48 and 52 mV decâ1, respectively. Our results open a new avenue for precise plasma-assisted engineering of MOF-derived hybrid hetero-structured electrocatalysts with rich oxygen vacancies and P dopants to simultaneously boost both half reactions in water electrolysis.</p
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