Design and Analyses of a MEMS Based Resonant Magnetometer

A novel design of a MEMS torsional resonant magnetometer based on Lorentz force is presented and fabricated. The magnetometer consists of a silicon resonator, torsional beam, excitation coil, capacitance plates and glass substrate. Working in a resonant condition, the sensor’s vibration amplitude is converted into the sensing capacitance change, which reflects the outside magnetic flux-density. Based on the simulation, the key structure parameters are optimized and the air damping effect is estimated. The test results of the prototype are in accordance with the simulation results of the designed model. The resolution of the magnetometer can reach 30 nT. The test results indicate its sensitivity of more than 400 mV/μT when operating in a 10 Pa vacuum environment

Origin of negative differential thermal resistance in a chain of two weakly coupled nonlinear lattices

Negative differential resistance in electronic conduction has been extensively studied, but it is not the case for its thermal counterpart, namely, negative differential thermal resistance (NDTR). We present a classical Landauer formula in which the nonlinearity is incorporated by the self-consistent phonon theory in order to study the heat flux across a chain consisting of two weakly coupled lattices. Two typical nonlinear models of hard and soft on-site potentials are discussed, respectively. It is shown that the nonlinearity has strong impacts on the occurring of NDTR. As a result, a transition from the absence to the presence of NDTR is observed. The origin of NDTR consists in the competition between the temperature difference, which acts as an external field, and the temperature-dependent thermal boundary conductance. Finally, the onset of the transition is clearly illustrated for this model. Our analytical calculation agrees reasonably well with numerical simulations.Comment: 6 pages, 8 figue

Therapeutic Effects of Coccomyxagloeobotrydiformis on the Metabolic Syndrome in Rats

Background/Aims: The metabolic syndrome (MS) is a cluster of metabolic changes that carry a high risk of cardiovascular disease (CVD). A newly discovered microalga, coccomyxagloeobotrydiformis (CGD), has been reported to improve ischemic stroke and metabolism-related indicators. We observed the therapeutic effects of CGD on MS and postulated the underlying mechanism. Methods: A diet-induced MS model in rats was used to observe the therapeutic effects of CGD on MS. Blood-glucose and lipid indices were measured using enzymatic colorimetric kits. A biologic data acquisition and analysis system (BL-420F) was used to evaluate cardiac function. Expression of mitochondrial respiratory chain (MRC) enzymes was measured by immunofluorescence staining. The proteins associated with oxidative stress, apoptosis and inflammation were detected by western blotting. Results: Body weight, abdominal circumference, fasting blood glucose , blood pressure as well as serum levels of total cholesterol, triglycerides and low-density lipoprotein-cholesterol were decreased whereas serum levels of high-density lipoprotein-cholesterol was increased in CGD-treated MS rats. CGD increased left-ventricular systolic pressure, left-ventricular end-diastolic pressure, left-ventricular systolic pressure maximum rate of increase and left-ventricular diastolic pressure maximum rate of decrease in MS rats with cardiovascular complications. CGD up-regulated expression of adenosine monophosphate-activated protein kinase and peroxisome proliferator activated receptor gamma coactivator 1-alpha in the heart, adipose tissue and skeletal muscle. Expression of the MRC subunits of ATPase 6, cytochrome b and succinate dehydrogenase complex, subunit-A was increased whereas that of uncoupling protein-2 decreased in different tissues. CGD showed anti-oxidation effects by increasing expression of superoxide dismutase and decreasing that of malondialdehyde. High expression of Bcl-2 and low expression of Bax and caspase-3 supported the anti-apoptotic effect of CGD on the cardiovascular complications of MS. Conclusion: CGD has a therapeutic effect on MS and associated cardiovascular complications by eliciting mitochondrial protection and having anti-oxidation and anti-apoptosis effects. CGD could be used for MS treatment

Notch1 Pathway Protects against Burn-Induced Myocardial Injury by Repressing Reactive Oxygen Species Production through JAK2/STAT3 Signaling

Oxidative stress plays an important role in burn-induced myocardial injury, but the cellular mechanisms that control reactive oxygen species (ROS) production and scavenging are not fully understood. This study demonstrated that blockade of Notch signaling via knockout of the transcription factor RBP-J or a pharmacological inhibitor aggravated postburn myocardial injury, which manifested as deteriorated serum CK, CK-MB, and LDH levels and increased apoptosis in vitro and in vivo. Interruption of Notch signaling increased intracellular ROS production, and a ROS scavenger reversed the exacerbated myocardial injury after Notch signaling blockade. These results suggest that Notch signaling deficiency aggravated postburn myocardial injury through increased ROS levels. Notch signaling blockade also decreased MnSOD expression in vitro and in vivo. Notably, Notch signaling blockade downregulated p-JAK2 and p-STAT3 expression. Inhibition of JAK2/STAT3 signaling with AG490 markedly decreased MnSOD expression, increased ROS production, and aggravated myocardial injury. AG490 plus GSI exerted no additional effects. These results demonstrate that Notch signaling protects against burn-induced myocardial injury through JAK2/STAT3 signaling, which activates the expression of MnSOD and leads to decreased ROS levels

The Large High Altitude Air Shower Observatory (LHAASO) Science White Paper

The Large High Altitude Air Shower Observatory (LHAASO) project is a new generation multi-component instrument, to be built at 4410 meters of altitude in the Sichuan province of China, with the aim to study with unprecedented sensitivity the spec trum, the composition and the anisotropy of cosmic rays in the energy range between 10$^{12}$ and 10$^{18}$ eV, as well as to act simultaneously as a wide aperture (one stereoradiant), continuously-operated gamma ray telescope in the energy range between 10$^{11}$ and $10^{15}$ eV. The experiment will be able of continuously surveying the TeV sky for steady and transient sources from 100 GeV to 1 PeV, t hus opening for the first time the 100-1000 TeV range to the direct observations of the high energy cosmic ray sources. In addition, the different observables (electronic, muonic and Cherenkov/fluorescence components) that will be measured in LHAASO will allow to investigate origin, acceleration and propagation of the radiation through a measurement of energy spec trum, elemental composition and anisotropy with unprecedented resolution. The remarkable sensitivity of LHAASO in cosmic rays physics and gamma astronomy would play a key-role in the comprehensive general program to explore the High Energy Universe. LHAASO will allow important studies of fundamental physics (such as indirect dark matter search, Lorentz invariance violation, quantum gravity) and solar and heliospheric physics. In this document we introduce the concept of LHAASO and the main science goals, providing an overview of the project.Comment: This document is a collaborative effort, 185 pages, 110 figure

AI is a viable alternative to high throughput screening: a 318-target study

: High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNet® model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery