Integrated Power Supply for MEMS Sensor

The recent expansion of wireless sensor networks and the rapid development of low-power consumption devices and MEMS devices have been driving research on harvester converting ambient energy into electricity to replace batteries that require costly maintenance. Harvesting energy from ambient environment vibration becomes an ideal power supply mode. The power supply module can be integrated with the MEMS sensor. There are many ways to convert ambient energy into electrical energy, such as photocells, thermocouples, vibration, and wind and so on. Among these energy-converting ways, the ambient vibration energy harvesting is more attractive because the vibration is everywhere in our daily environment. Based on the analysis of the basic theory of the electret electrostatic harvester, the basic equations and equivalent analysis model of electret electrostatic harvester are established. The experimental tests for the output performance of electret electrostatic harvester are completed. For the electret material, the material itself can also provide a constant voltage to avoid the use of additional power, which provides an effective way for electrostatic harvesting. Therefore, the electret electrostatic harvesting structure is a kind of ideal energy harvesting method using ambient vibration and can be easily integrated with the MEMS system

Alcohol-induced severe acute pancreatitis followed by hemolytic uremic syndrome managed with continuous renal replacement therapy

BACKGROUND: Acute kidney injury in patients with acute pancreatitis carries a poor prognosis. Hemolytic uremic syndrome (HUS) is characterized by non-immune hemolytic anemia, thrombocytopenia, and renal failure caused by platelet thrombi in the microcirculation of the kidney, and though rare in adults it is associated with high mortality and a high rate of chronic renal failure. CASE PRESENTATION: Herein, we report a case of alcohol-induced acute pancreatitis in a 38-year-old Chinese female complicated by HUS. Her renal function progressively deteriorated in 2 days, and daily continuous renal replacement therapy (CRRT) was thus performed for a total of 13 treatments. She also received intermittent transfusions of fresh frozen plasma. Her renal failure was successfully managed, with subsequent return of normal renal function. She was discharged 1 month after admission and follow-up at 3 months revealed normal urea and creatinine. CONCLUSION: CRRT was shown to be useful for the treatment of HUS following acute pancreatitis. Prior case reports and our case should remind clinicians that HUS is a possible complication of acute pancreatitis. This study highlights the importance of early diagnosis and prompt initiation of CRRT to prevent mortality and improve outcomes

Dexmedetomidine post-treatment attenuates cardiac ischaemia/reperfusion injury by inhibiting apoptosis through HIF-1α signalling.

Hypoxia-inducible factor 1α (HIF-1α) plays a critical role in the apoptotic process during cardiac ischaemia/reperfusion (I/R) injury. This study aimed to investigate whether post-treatment with dexmedetomidine (DEX) could protect against I/R-induced cardiac apoptosis in vivo and in vitro via regulating HIF-1α signalling pathway. Rat myocardial I/R was induced by occluding the left anterior descending artery for 30 minutes followed by 6-hours reperfusion, and cardiomyocyte hypoxia/reoxygenation (H/R) was induced by oxygen-glucose deprivation for 6 hours followed by 3-hours reoxygenation. Dexmedetomidine administration at the beginning of reperfusion or reoxygenation attenuated I/R-induced myocardial injury or H/R-induced cell death, alleviated mitochondrial dysfunction, reduced the number of apoptotic cardiomyocytes, inhibited the activation of HIF-1α and modulated the expressions of apoptosis-related proteins including BCL-2, BAX, BNIP3, cleaved caspase-3 and cleaved PARP. Conversely, the HIF-1α prolyl hydroxylase-2 inhibitor IOX2 partly blocked DEX-mediated cardioprotection both in vivo and in vitro. Mechanistically, DEX down-regulated HIF-1α expression at the post-transcriptional level and inhibited the transcriptional activation of the target gene BNIP3. Post-treatment with DEX protects against cardiac I/R injury in vivo and H/R injury in vitro. These effects are, at least in part, mediated via the inhibition of cell apoptosis by targeting HIF-1α signalling

catena-Poly[[diaqua­bis­{μ2-3,5-bis­[(pyridin-4-yl)methyl­amino]­benzoato}nickel] monohydrate]

In the title coordination polymer, {[Ni(C19H17N4O2)2(H2O)2]·H2O}n, the Ni2+ cation is located on an inversion center and coordinated by two carboxyl­ate O atoms from two different 3,5-bis­(pyridin-4-yl­methyl­amino)­benzoate anions, two O atoms from two coordinated water mol­ecules and two N atoms from two different 3,5-bis­(pyridin-4-yl­methyl­amino)­benzoate anions, displaying a slightly distorted NiN2O4 octa­hedral geometry. Each 3,5-bis­(pyridin-4-yl­methyl­amino)­benzoate anion acts as a μ2-bridge, linking different nickel ions into a chain along [010]. In the crystal, adjacent chains are further linked through N—H⋯O, O—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds into a three-dimensional network. The coordinated water mol­ecules and a disordered water mol­ecule of hydration with 0.50 site occupancy play an important role in the formation of these hydrogen-bonding inter­actions

Density-driven higher-order topological phase transitions in amorphous solids

Amorphous topological states, which are independent of the specific spatial distribution of microscopic constructions, have gained much attention. Recently, higher-order topological insulators, which are a new class of topological phases of matter, have been proposed in amorphous systems. Here, we propose a density-driven higher-order topological phase transition in a two-dimensional amorphous system. We demonstrate that the amorphous system hosts a topological trivial phase at low density. With an increase in the density of lattice sites, the topological trivial phase converts to a higher-order topological phase characterized by a quantized quadrupole moment and the existence of topological corner states. Furthermore, we confirm that the density-driven higher-order topological phase transition is size dependent. In addition, our results should be general and equally applicable to three-dimensional amorphous systems. Our findings may greatly enrich the study of higher-order topological states in amorphous systems

Fast Determination of 20 Pesticides Residues in Wheat Using QuEChERS-modified and GC-MS/MS

A method for the determination of 20 pesticides residues in wheat by QuEChERS coupled with GC-MS/MS was developed. The effect of sorbent for purification was investigated. The matrix effect was also studied. The results showed that: (1) Compared with pretreatment method in 7.1.2 of GB 23200. 113—2018, this method reduced the amount of anhydrous MgSO4 added from 1200 mg to 400 mg, the amount of PSA added from 400 mg to 100 mg, and the amount of C18 added from 400 mg to 200 mg. Also, the add 100 mg GCB that could effectively remove the pigment in the wheat extract by optimizing the purification adsorbent. (2) The calibration curves of the 20 pesticides showed good linearity in the range of 5–500 ng/mL with the correlation coefficients (R2) greater than 0.99. The LOD ranged from 0.01 to 0.16 μg/kg and LOQ ranged from 0.04 to 0.52 μg/kg for 20 pesticides. The matrix effects of the 20 pesticides varied greatly. (3) At the spiked level of 80.0 μg/kg, 200.0 μg/kg and 400.0 μg/kg the average recoveries were 75.24%-98.29%, 82.01%-105.71% and 94.91%-106.14% respectively, and relative standard deviations (RSDs) were 0.57%-3.13%, 0.67%-3.98% and 1.26%-3.08% respectively. The method met the requirements of pesticide residue analysis

mGluR5 antagonism inhibits cocaine reinforcement and relapse by elevation of extracellular glutamate in the nucleus accumbens via a CB1 receptor mechanism.

Metabotropic glutamate receptor 5 (mGluR5) antagonism inhibits cocaine self-administration and reinstatement of drug-seeking behavior. However, the cellular and molecular mechanisms underlying this action are poorly understood. Here we report a presynaptic glutamate/cannabinoid mechanism that may underlie this action. Systemic or intra-nucleus accumbens (NAc) administration of the mGluR5 antagonist 2-methyl-6-(phenylethynyl)-pyridine (MPEP) dose-dependently reduced cocaine (and sucrose) self-administration and cocaine-induced reinstatement of drug-seeking behavior. The reduction in cocaine-taking and cocaine-seeking was associated with a reduction in cocaine-enhanced extracellular glutamate, but not cocaine-enhanced extracellular dopamine (DA) in the NAc. MPEP alone, when administered systemically or locally into the NAc, elevated extracellular glutamate, but not DA. Similarly, the cannabinoid CB1 receptor antagonist, rimonabant, elevated NAc glutamate, not DA. mGluR5s were found mainly in striatal medium-spiny neurons, not in astrocytes, and MPEP-enhanced extracellular glutamate was blocked by a NAc CB1 receptor antagonist or N-type Ca++ channel blocker, suggesting that a retrograde endocannabinoid-signaling mechanism underlies MPEP-induced glutamate release. This interpretation was further supported by our findings that genetic deletion of CB1 receptors in CB1-knockout mice blocked both MPEP-enhanced extracellular glutamate and MPEP-induced reductions in cocaine self-administration. Together, these results indicate that the therapeutic anti-cocaine effects of mGluR5 antagonists are mediated by elevation of extracellular glutamate in the NAc via an endocannabinoid-CB1 receptor disinhibition mechanism

Molecular Beam Epitaxy Growth of Superconducting LiFeAs Film on SrTiO3(001) Substrate

The stoichiometric "111" iron-based superconductor, LiFeAs, has attacted great research interest in recent years. For the first time, we have successfully grown LiFeAs thin film by molecular beam epitaxy (MBE) on SrTiO3(001) substrate, and studied the interfacial growth behavior by reflection high energy electron diffraction (RHEED) and low-temperature scanning tunneling microscope (LT-STM). The effects of substrate temperature and Li/Fe flux ratio were investigated. Uniform LiFeAs film as thin as 3 quintuple-layer (QL) is formed. Superconducting gap appears in LiFeAs films thicker than 4 QL at 4.7 K. When the film is thicker than 13 QL, the superconducting gap determined by the distance between coherence peaks is about 7 meV, close to the value of bulk material. The ex situ transport measurement of thick LiFeAs film shows a sharp superconducting transition around 16 K. The upper critical field, Hc2(0)=13.0 T, is estimated from the temperature dependent magnetoresistance. The precise thickness and quality control of LiFeAs film paves the road of growing similar ultrathin iron arsenide films.Comment: 7 pages, 6 figure