Search

Purpose. The available nomograms used to predict acute pancreatitis (AP) are not comprehensive. We sought to investigate the effect of red blood cell distribution width (RDW)-albumin ratio (RA) on prognosis of patients with AP and develop a new nomogram to identify AP patients at high risk for mortality. Methods. We used data from the Medical Information Mart for Intensive Care IV version 2.0 (MIMIC-IV v2.0). A total of 487 patients with acute pancreatitis were included. Patients enrolled in the study were randomly assigned to the training set and validation set at a 7 : 3 ratio. According to the 30-day mortality rate, the data were divided into a survival group and a death group. Multivariate logistic regression was used to establish a prognostic nomogram for predicting the 30-day mortality in AP patients. The area under the receiver operating characteristic curve (AUC), calibration curve, the net reclassification improvement (NRI), the integrated discrimination improvement (IDI), and a decision curve analysis (DCA) are used to verify the overall performance of the model. Results. Among 487 patients, 54 patients died (11.1%). 338 patients were assigned to the training cohort and 149 were assigned to the validation cohort. The multivariate analysis results showed that RA, age, heart rate, temperature, AST/ALT, BUN, hemoglobin, potassium, and bilirubin were independent risk factors. The prediction performance of the newly established nomogram was better than those of other common scoring systems (including SOFA, OASIS, and APSIII). The nomogram suggests that RA (OR = 1.706, 95% CI: 1.367–2.185) is the most significant laboratory test indicator influencing prognosis. Conclusion. The new nomogram incorporating RA performed well in predicting AP short-term mortality. A prospective study with a larger sample is needed to validate our findings. [ABSTRACT FROM AUTHOR]

The most distal portion of the ventricular conduction system (VCS) contains cardiac Purkinje cells (PCs), which are essential for synchronous activation of the ventricular myocardium. Contactin-2 (CNTN2), a member of the immunoglobulin superfamily of cell adhesion molecules (IgSF-CAMs), was previously identified as a marker of the VCS. Through differential transcriptional profiling, we discovered two additional highly enriched IgSF-CAMs in the VCS: NCAM-1 and ALCAM. Immunofluorescence staining showed dynamic expression patterns for each IgSF-CAM during embryonic and early postnatal stages, but ultimately all three proteins became highly enriched in mature PCs. Mice deficient in NCAM-1, but not CNTN2 or ALCAM, exhibited defects in PC gene expression and VCS patterning, as well as cardiac conduction disease. Moreover, using ST8sia2 and ST8sia4 knockout mice, we show that inhibition of post-translational modification of NCAM-1 by polysialic acid leads to disrupted trafficking of sarcolemmal intercalated disc proteins to junctional membranes and abnormal expansion of the extracellular space between apposing PCs. Taken together, our data provide insights into the complex developmental biology of the ventricular conduction system. [ABSTRACT FROM AUTHOR]

Combined with the spatial data processing capability of geographic information systems (GIS), a three-dimensional (3D) landslide surge height calculation method is proposed based on grid column units. First, the data related to the landslide are rasterized to form grid columns, and a force analysis model of 3D landslides is established. Combining the vertical strip method with Newton's laws of motion, dynamic equilibrium equations are established to solve for the surge height. Moreover, a 3D landslide surge height calculation expansion module is developed in the GIS environment, and the results are compared with those of the two-dimensional Pan Jiazheng method. Comparisons show that the maximum surge height obtained by the proposed method is 24.6 % larger than that based on the Pan Jiazheng method. Compared with the traditional two-dimensional method, the 3D method proposed in this paper better represents the actual spatial state of the landslide and is more suitable for risk assessment. [ABSTRACT FROM AUTHOR]

Background: Atrial standstill is an arrhythmogenic condition characterized by the absence of spontaneous electrical and mechanical atrial activity or in response to stimulation. There are few reported familial cases which have been associated with SCN5A mutations cosegregating with GJA5 or RYR2; however, isolated SCN5Amutations are rare.Objective: The purpose of this study was to determine the clinical and biophysical consequence of a novel SCN5A mutation identified in a family with progressive atrial standstill and sudden death.Methods: The family of a sporadic case of congenital atrial standstill underwent genetic screening. Human Embryonic Kidney 293 cells were transfected with wild-type (WT) or mutant SCN5A cDNAs. Biophysical properties were studied using whole-cell using patch clamp methods.Results: A novel homozygous SCN5A mutation, p.V1340L, was identified in the proband and her sister. The proband had complete atrial standstill whereas the sister had partial atrial standstill. Heterozygous mutations were identified in the mother, father, and brother. All three had normalsinus rhythm and were asymptomatic. The mutant Nav1.5(V1340L) reduced Nav1.5 current density as well as showed a depolarizing shift in the voltage-dependent steady-state activation(WT:-35.3±1.62mV;V1340L:-22.4±2.59mV;P=0.001).Conclusions: A homozygous loss-of-function SCN5A mutation likely results in atrial standstill and sudden death due to suppression of initiation of action potential. [ABSTRACT FROM AUTHOR]

This study aims to analyze and visualize the traffic performance condition of the highway network in the Mississippi Gulf Coast area using the traffic flow models to identify the congested links in a Geographic Information System (GIS). The traffic performance condition of the highway network was estimated based on each link's average daily traffic, design hourly volume, link capacity, and volume-to-capacity ratio (v/c), which were calculated using the traffic flow models in Highway Capacity Manual 2010. County polygons with geographical information were obtained from the Mississippi Automated Resource Information System (MARIS), and ArcMap GIS was used to symbolically present as geographic information the volume to capacity ratio of each link of the study area. The risk traffic area was also presented considering flood inundation in hurricane. The statistical analysis results indicated that among the total of 4,274 links in the study area, 4,231 links have v/c ratio values under 1.0 and 16 links have v/c ratio values above 1.0, and the links with high v/c ratios may indicate the highly congested locations. [ABSTRACT FROM AUTHOR]

Compared with traditional conductive fillers, carbon nanotubes (CNTs) have unique advantages, i.e., excellent mechanical properties, high electrical conductivity and thermal stability. Nanocomposites as piezoresistive films provide an interesting approach for the realization of large area strain sensors with high sensitivity and low manufacturing costs. A polymer-based nanocomposite with carbon nanomaterials as conductive filler can be deposited on a flexible substrate of choice and this leads to mechanically flexible layers. Such sensors allow the strain measurement for both integral measurement on a certain surface and local measurement at a certain position depending on the sensor geometry. Strain sensors based on carbon nanostructures can overcome several limitations of conventional strain sensors, e.g., sensitivity, adjustable measurement range and integral measurement on big surfaces. The novel technology allows realizing strain sensors which can be easily integrated even as buried layers in material systems. In this review paper, we discuss the dependence of strain sensitivity on different experimental parameters such as composition of the carbon nanomaterial/polymer layer, type of polymer, fabrication process and processing parameters. The insights about the relationship between film parameters and electromechanical properties can be used to improve the design and fabrication of CNT strain sensors. [ABSTRACT FROM AUTHOR]

Dealing with crosscutting concerns has been a critical problem in software development processes. To facilitate handling crosscutting concerns at design phases, we proposed an as-pect-oriented modeling and integration approach with UML activity diagrams. The primary concerns are depicted with UML activity diagrams as primary models, whereas crosscutting concerns are described with aspectual extended activity diagrams as aspect models. Aspect models can be integrated into primary models automatically. The AOM approach can reduce the complexity of design models. However, potential faults that violate desired properties of the software system might still be introduced during the modeling or integration processes. The verification technique is well-known for its ability to assure the correctness of models and uncover design problems before implementation. We propose a framework to verify aspect-oriented UML activity diagrams based on Petri net verification techniques. For verification purpose, we transform the integrated activity diagrams into Petri nets and prove the con-sistency of the transformation. Then, crosscutting concerns in system requirements are refined to properties in the form of CTL formulas. Finally, the Petri nets are verified against the formalized properties to report whether the aspect-oriented design models satisfies the requirements. Furthermore, we implement a tool named Jasmine-AOV to support the veri-fication process. Case studies are conducted to evaluate the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

The existing techniques for reachability analysis of linear hybrid systems do not scale well to the problem size of practical interest. The performance of existing techniques is even worse for reachability analysis of a composition of several linear hybrid automata. In this paper, we present an efficient path-oriented approach to bounded reachability analysis of composed systems modeled by linear hybrid automata with synchronization events. It is suitable for analyzing systems with many components by selecting critical paths, while this task was quite insurmountable before because of the state explosion problem. This group of paths will be transformed to a group of linear constraints, which can be solved by a linear programming solver efficiently. This approach of symbolic execution of paths allows design engineers to check important paths, and accordingly increase the faith in the correctness of the system. This approach is implemented into a prototype tool Bounded reAchability CHecker (BACH). The experimental data show that both the path length and the number of participant automata in a system checked using BACH can scale up greatly to satisfy practical requirements. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented related to the targeted conditional gene knockout in human embryonic stem cells.

The generation and expansion of diverse cardiovascular cell lineages is a critical step during human cardiogenesis, with major implications for congenital heart disease. Unravelling the mechanisms for the diversification of human heart cell lineages has been hampered by the lack of genetic tools to purify early cardiac progenitors and define their developmental potential. Recent studies in the mouse embryo have identified a multipotent cardiac progenitor that contributes to all of the major cell types in the murine heart. In contrast to murine development, human cardiogenesis has a much longer onset of heart cell lineage diversification and expansion, suggesting divergent pathways. Here we identify a diverse set of human fetal ISL1+ cardiovascular progenitors that give rise to the cardiomyocyte, smooth muscle and endothelial cell lineages. Using two independent transgenic and gene-targeting approaches in human embryonic stem cell lines, we show that purified ISL1+ primordial progenitors are capable of self-renewal and expansion before differentiation into the three major cell types in the heart. These results lay the foundation for the generation of human model systems for cardiovascular disease and novel approaches for human regenerative cardiovascular medicine. [ABSTRACT FROM AUTHOR]

Recent studies have demonstrated that the LIM homeodomain transcription factor Islet1 (Isl1) marks pluripotent cardiovascular progenitor cells and is required for proliferation, survival, and migration of recently defined second heart field progenitors. Factors that are upstream of Isl1 in cardiovascular progenitors have not yet been defined. Here we demonstrate that β-catenin is required for Isl1 expression in cardiac progenitors, directly regulating the Isl1 promoter. Ablation of β-catenin in Isl1-expressing progenitors disrupts multiple aspects of cardiogenesis, resulting in embryonic lethality at E13. β-Catenin is also required upstream of a number of genes required for pharyngeal arch, outflow tract, and/or atrial septal morphogenesis, including Tbx2, Tbx3, Wnt11, Shh, and Pitx2. Our findings demonstrate that β-catenin signaling regulates proliferation and survival of cardiac progenitors. [ABSTRACT FROM AUTHOR]

Mutations in T-box genes are the cause of several congenital diseases and are implicated in cancer. Tbx20-null mice exhibit severely hypoplastic hearts and express Tbx2, which is normally restricted to outflow tract and atrioventricular canal, throughout the heart. Tbx20 mutant hearts closely resemble those seen in mice overexpressing Tbx2 in myocardium, suggesting that upregulation of Tbx2 can largely account for the cardiac phenotype in Tbx20-null mice. We provide evidence that Tbx2 is a direct target for repression by Tbx20 in developing heart. We have also found that Tbx2 directly binds to the Nmyc1 promoter in developing heart, and can repress expression of the Nmyc1 promoter in transient transfection studies. Repression of Nmyc1 (N-myc) by aberrantly regulated Tbx2 can account in part for the observed cardiac hypoplasia in Tbx20 mutants. Nmyc1 is required for growth and development of multiple organs, including the heart, and overexpression of Nmyc1 is associated with childhood tumors. Despite its clinical relevance, the factors that regulate Nmyc1 expression during development are unknown. Our data present a paradigm by which T-box proteins regulate regional differences in Nmyc1 expression and proliferation to effect organ morphogenesis. We present a model whereby Tbx2 directly represses Nmyc1 in outflow tract and atrioventricular canal of the developing heart, resulting in relatively low proliferation. In chamber myocardium, Tbx20 represses Tbx2, preventing repression of Nmyc1 and resulting in relatively high proliferation. In addition to its role in regulating regional proliferation, we have found that Tbx20 regulates expression of a number of genes that specify regional identity within the heart, thereby coordinating these two important aspects of organ development. [ABSTRACT FROM AUTHOR]

OBJECTIVE -- To investigate the association between neck circumference and central obesity, overweight, and metabolic syndrome in Chinese individuals with type 2 diabetes. RESEARCH DESIGN AND METHODS-- k total of 3,182 diabetic subjects (aged 20-80 years) were recruited from 15 community health centers in Beijing using a multistage random sampling approach. RESULTS-- Receiver operating characteristic analysis showed that the area under the curve for neck circumference and central obesity was 0.77 for men and 0.75 for women (P < 0.001). Furthermore, a neck circumference of ≥38 cm for men and ≥35 cm for women was the best cutoff point for determining overweight subjects. A neck circumference of ≥39 cm for men and ≥35 cm for women was the best cutoff point to determine subjects with metabolic syndrome. CONCLUSIONS -- In the present study, neck circumference is positively related with BMI, waist circumference, and metabolic syndrome in Chinese individuals with type 2 diabetes. [ABSTRACT FROM AUTHOR]