A constitutive model is developed to capture the complex rheological behavior of dense granular flows (solid volume fraction ranging from 0.45 to 0.62) in the quasi-static, intermediate, and inertial ...regimes. The principal contribution of this work is the development of a contact stress model (CSM) that is a statistical closure for the average contact stress experienced by particles, which is derived from a micromechanical model for the stress. This modeling approach naturally gives rise to the dependence of average contact stress on the average contact force and relevant descriptors of microstructure, which are the average coordination number and the fabric tensor. An expression for the average contact force is obtained from the contact force probability density function that has the same form in many granular flows. Appropriate closures for the coordination number and the fabric tensor are obtained by solving their respective modeled evolution equations proposed by Sun and Sundaresan J. Fluid Mech. 2011, 682, 590–616. CSM’s predictive capability is tested in homogeneous shear flow using discrete element model (DEM) simulation data corresponding to the quasi-static, intermediate, and inertial regimes. It is found that CSM’s predictions match DEM data very closely in all three regimes.
Cellular and tissue defects associated with insulin resistance are coincident with transcriptional abnormalities and are improved after insulin sensitization with thiazolidinedione (TZD) PPARγ ...ligands. We characterized 72 human subjects by relating their clinical phenotypes with functional pathway alterations. We transcriptionally profiled 364 biopsies harvested before and after hyperinsulinemic-euglycemic clamp studies, at baseline and after 3-month TZD treatment. We have identified molecular and functional characteristics of insulin resistant subjects and distinctions between TZD treatment responder and nonresponder subjects. Insulin resistant subjects exhibited alterations in skeletal muscle (e.g., glycolytic flux and intramuscular adipocytes) and adipose tissue (e.g., mitochondrial metabolism and inflammation) that improved relative to TZD-induced insulin sensitization. Pre-TZD treatment expression of MLXIP in muscle and HLA-DRB1 in adipose tissue from insulin resistant subjects was linearly predictive of post-TZD insulin sensitization. We have uniquely characterized coordinated cellular and tissue functional pathways that are characteristic of insulin resistance, TZD-induced insulin sensitization, and potential TZD responsiveness.
The metabolic stress placed on skeletal muscle by aerobic exercise promotes acute and long-term health benefits in part through changes in gene expression. However, the transducers that mediate ...altered gene expression signatures have not been completely elucidated. Regulated in development and DNA damage 1 (REDD1) is a stress-induced protein whose expression is transiently increased in skeletal muscle following acute aerobic exercise. However, the role of this induction remains unclear. Because REDD1 altered gene expression in other model systems, we sought to determine whether REDD1 induction following acute exercise altered the gene expression signature in muscle. To do this, wild-type and REDD1-null mice were randomized to remain sedentary or undergo a bout of acute treadmill exercise. Exercised mice recovered for 1, 3, or 6 h before euthanization. Acute exercise induced a transient increase in REDD1 protein expression within the plantaris only at 1 h postexercise, and the induction occurred in both cytosolic and nuclear fractions. At this time point, global changes in gene expression were surveyed using microarray. REDD1 induction was required for the exercise-induced change in expression of 24 genes. Validation by RT-PCR confirmed that the exercise-mediated changes in genes related to exercise capacity, muscle protein metabolism, neuromuscular junction remodeling, and Metformin action were negated in REDD1-null mice. Finally, the exercise-mediated induction of REDD1 was partially dependent upon glucocorticoid receptor activation. In all, these data show that REDD1 induction regulates the exercise-mediated change in a distinct set of genes within skeletal muscle.
Compared to legacy wavelength division multiplexing networks, elastic optical networks (EONs) have added flexibility to network deployment and management. EONs can include previously available ...functionality, such as signal regeneration and wavelength conversion, as well as new features such as finer-granularity spectrum assignment and modulation conversion. Yet each added feature adds to the cost of the network. In order to quantify the potential benefit of each functionality, we present a link-based mixed-integer linear programming (MILP) formulation to solve the optimal resource allocation problem. We then propose a recursive model in order to either augment existing network deployments (spectrum and regenerators) or speed up the resource allocation computation time for larger networks with higher traffic demand requirements than can be solved using an MILP. We show through simulation that systems equipped with signal regenerators or wavelength converters require a notably smaller total bandwidth, depending on the topology of the network. We also show that the suboptimal recursive solution speeds up the calculation and makes the running time more predictable, compared to the optimal MILP.
Epithelial–myoepithelial carcinoma (EMC) is a rare salivary gland malignancy. Controversy exists in the literature regarding the effectiveness of treatment modalities employed in the management of ...EMC. This systematic review was undertaken to understand the presenting characteristics of EMC and identify the most common treatment modalities and their associated outcomes, in order to help guide an evidenced-based approach to the algorithm of care. The MEDLINE (PubMed) and Embase databases were searched (up to February 23, 2022), and the review was performed in accordance with the PRISMA statement. Fifty-seven studies (51 case reports and six case series) describing 91 cases of EMC were included in this review. In the included studies, a slow-growing painless mass was the most common presenting clinical feature. EMC was most frequently treated with surgery alone (65%). Local disease recurrence occurred in 24% of the cases and metastatic disease in 11%. A positive surgical margin was found to be associated with a higher risk of recurrence (P < 0.001), while adjuvant radiotherapy was associated with a decreased risk of local disease recurrence (P = 0.034). Metastatic disease and multimodal therapy were found to be associated with decreased disease-free and overall survival (all P < 0.05). The current literature supports surgery with clear margins as the mainstay of treatment for EMC of the salivary and seromucous glands of the head and neck. In certain situations, radiotherapy may improve disease-free survival.
The understanding of genetic alterations that drive non-small cell lung cancer (NSCLC) is evolving. As many of these molecularly-defined subtypes are potentially actionable, new strategies in ...molecular diagnostics and targeted therapies in NSCLC to detect and treat them are being explored. At the International Association for Study of Lung Cancer 19th World Conference, several abstracts and oral presentations related to this topic. In this report, we discuss some of these updates.
Abstract
Concentrated solar power (CSP) with thermal storage (TES) can generate continuous power output. It can be used for various applications by overcoming the intermittent solar radiation. As ...heat losses occur in absorber because of heat flux, tracking, optical errors. Hence, improving efficiency arises. Reducing heat loss is vital. The absorbers are volumetric, cavity, tubular liquid, solid particle-type. The occurrence of heat flux on absorbers from heliostats. Performance affects because of clouds in transient conditions. The review focuses on advances in solar absorber designs. It concentrates on meeting sustainable development’s energy and power requirements.
Abstract
The deliberate introduction of vegetation in urban environments, referred to as urban greening, is known to improve outdoor thermal comfort and mitigate the effects of Urban Heat Island in ...cities. Urban greening can be applied on ground level or elevated parks, roof tops, and building facades. The main parameters that affect plant growth are space, light, water, humidity, oxygen, carbon dioxide, mineral elements, and temperature. Of these parameters, light and temperature are the ones more unlikely to be supplemented in a non-controlled urban setting. This research presents the development of an automated workflow that facilitates design decisions on vegetation growth potential and vegetation species selection within their climatic and geometrical context. This novel scripting-based prototype uses hourly radiation results to extract location specifications, such as photoperiod, hardiness zone, and hourly annual Daily Light Integral values on a user-defined grid. It then seamlessly compares the data against seasonal light and soil temperature requirements of listed cultivars to evaluate their suitability within the constraints of the analysis area. A basic plant dataset is created that is open to expansion based on plants growth data availability. This automated workflow can be employed by agriculturalists, urban planners, and landscape designers to perform vegetation selection for applications such as urban greening in dense contexts or vertical farms.
Deoxyribonucleic acid (DNA), being the main biomolecule of life, has been studied extensively in terms of its electronic properties, charge transport mechanisms and potential use in nano-electronic ...devices. The ability of DNA to self-replicate, self-assemble and mediate charge transfer has made it an interesting molecule to multidisciplinary researchers. However, not much attention has been given to ribonucleic acid (RNA), which is an equally important biomolecule that shares some common features with DNA. Elucidation of RNA’s electronic behavior could provide more information regarding its electronic properties, potentially offering a new biomolecule for application in bioelectronics. In this work, RNA samples integrated within two metal electrodes were subjected to positive and negative bias potentials and their resulting current profiles were investigated. Interestingly, current rectification similar to electric field-induced semi-conductive behavior of conventional Schottky junctions was observed for all RNA samples tested, indicating highly characteristic RNA-specific Schottky profiles. A non-linear profile was observed from the current–voltage (
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) characteristics of gold (Au)-RNA-Au structures showing resemblance to metal-DNA structures investigated previously. Various solid-state parameters such as turn-on voltage, shunt resistance, series resistance and ideality factor were also calculated to further understand the biomaterial’s solid-state behavior. These results successfully demonstrated the exciting observation of the semi-conductive-like behavior of RNA which could be utilized as a tool in molecular electronics.
•Pseudo-turbulence heat flux closure was modified and implemented in the two-fluid model.•Pseudo-turbulence heat flux is a significant contributor to the evolution of the fluid ...temperature.•Pseudo-turbulence heat flux cannot be neglected for high Reynolds number dilute cases.
The Eulerian–Eulerian two-fluid model is widely used for computational fluid dynamics simulations of gas–solid flows. For non-isothermal flows, the averaged conservation equations solved in the two-fluid model require closures for drag, gas–solid heat transfer, pseudo-turbulent velocity fluctuations and the pseudo-turbulent heat flux (PTHF). However, the pseudo-turbulence terms are usually neglected in two-fluid simulations due to the lack of accurate correlations. With the increase in computational power, closures for these terms are now available from particle-resolved direct-numerical simulation (PR-DNS). Here, the PTHF closure as well as the heat-transfer closure (i.e.,the Nusselt number) extracted from PR-DNS are implemented in the two-fluid thermal energy equation in OpenFOAM. The implementation is validated by comparing the simulation results with the PR-DNS data for the temperature profiles. Based on the analysis of the thermal energy budget, the PTHF can have a significant contribution and neglecting it can lead to large errors.
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