Self-Biased Bidomain LiNbO3/Ni/Metglas Magnetoelectric Current Sensor.

The article is devoted to the theoretical and experimental study of a magnetoelectric (ME) current sensor based on a gradient structure. It is known that the use of gradient structures in magnetostrictive-piezoelectric composites makes it possible to create a self-biased structure by replacing an external magnetic field with an internal one, which significantly reduces the weight, power consumption and dimensions of the device. Current sensors based on a gradient bidomain structure LiNbO3 (LN)/Ni/Metglas with the following layer thicknesses: lithium niobate-500 µm, nickel-10 µm, Metglas-29 µm, operate on a linear section of the working characteristic and do not require the bias magnetic field. The main characteristics of a contactless ME current sensor: its current range measures up to 10 A, it has a sensitivity of 0.9 V/A, its current consumption is not more than 2.5 mA, and its linearity is maintained to an accuracy of 99.8%. Some additional advantages of a bidomain lithium niobate-based current sensor are the increased sensitivity of the device due to the use of the bending mode in the electromechanical resonance region and the absence of a lead component in the device.

Mechanism of large optical nonlinearity in gold nanoparticle films.

The Z-scan technique, using femtosecond (fs) laser pulses at 1480 nm laser pulses, was used to measure the nonlinear optical properties of gold (Au) nanoparticle (NP) films made by both nanosecond (ns) and fs pulsed laser deposition (PLD) in vacuum. At irradiance levels of 1×1012 Wm-2, the ns-PLD films displayed induced absorption with ß=4×10-5 mW-1, and a negative lensing effect with n2=-4.7×10-11 m2 W-1 with somewhat smaller values for the fs-PLD films. These values of n2 imply an unphysically large change in the real part of the refractive index, demonstrating the need to take account of nonlinear changes of the Fresnel coefficients and multiple beam interference in Z-scan measurements on nanoscale films. Following this approach, the Z-scan observations were analyzed to determine the effective complex refractive index of the NP film at high irradiance. It appears that at high irradiance the NP film behaves as a metal, while at low irradiance it behaves as a low-loss dielectric. Thus, it is conjectured that, for high irradiance near the waist of the Z-scan laser beam, laser driven electron tunneling between NPs gives rise to metal-like optical behavior.

Frequency and reasons of donor deferral prior to blood donation process: a single centre experience.

OBJECTIVE: The aim of the study was to determine the frequency and reasons for donor deferral prior to the blood donation process in our population. BACKGROUND: Transfusion is an irreversible event that carries potential risks as well as benefits to the recipient. Therefore, donor selection prior to blood donation is one of the most important steps in ensuring the safety of blood and blood products. METHODS: A cross-sectional study was carried out at the blood bank department in our hospital from January 2012 to December 2014. All the blood donors who visited our department in the study period were included in this study. RESULTS: A total of 25 901 potential donations were recorded during the study period, comprising 24 309 (93·8%) replacement and 1592 (6·2%) voluntary donations. Females accounted for only 222 (0·9%) of potential donations. Deferral occurred in 3156 (12·2%) of attempts; 280 (1·1%) were permanently deferred, while 2876 (11·1%) were temporarily deferred. The most common reason for permanent deferral was a history of hepatitis B infection (n = 147, 4·7% of all deferrals). Major reasons for temporary donor deferral were low levels of haemoglobin (n = 971, 30·76%), low levels of platelets (n = 611, 19·35%) and previous history of jaundice (n = 192, 6·1%). CONCLUSIONS: This study reported a fairly similar pattern of donor deferrals as in other regional studies. Low haemoglobin levels and a history of hepatitis B infection were the most common factors for temporary and permanent donor deferrals, respectively.

Blockade of the dorsomedial hypothalamus and the perifornical area inhibits respiratory responses to arousing and stressful stimuli.

The dorsomedial hypothalamus (DMH) and the perifornical area (DMH/PeF) is one of the key regions of central autonomic processing. Previous studies have established that this region contains neurons that may be involved in respiratory processing; however, this has never been tested in conscious animals. The aim of our study was to investigate the involvement of the DMH/PeF area in mediating respiratory responses to stressors of various intensities and duration. Adult male Wistar rats (n = 8) received microinjections of GABAA agonist muscimol or saline into the DMH/PeF bilaterally and were subjected to a respiratory recording using whole body plethysmography. Presentation of acoustic stimuli (500-ms white noise) evoked transient responses in respiratory rate, proportional to the stimulus intensity, ranging from +44 ± 27 to +329 ± 31 cycles/min (cpm). Blockade of the DMH/PeF almost completely abolished respiratory rate and tidal volume responses to the 40- to 70-dB stimuli and also significantly attenuated responses to the 80- to 90-dB stimuli. Also, it significantly attenuated respiratory rate during the acclimatization period (novel environment stress). The light stimulus (30-s 2,000 lux) as well as 15-min restraint stress significantly elevated respiratory rate from 95 ± 4.0 to 236 ± 29 cpm and from 117 ± 5.2 to 189 ± 13 cpm, respectively; this response was abolished after the DMH/PeF blockade. We conclude that integrity of the DMH/PeF area is essential for generation of respiratory responses to both stressful and alerting stimuli.

Both Ox1R and Ox2R orexin receptors contribute to the cardiorespiratory response evoked from the perifornical hypothalamus.

Orexin/hypocretin neurons are located in and around the perifornical hypothalamus. Disinhibition of this area in the anaesthetized preparation evokes cardiorespiratory changes that can be reduced to nearly half or more by systemic Almorexant, a dual receptor antagonist of the two known orexin receptors, Ox1R and Ox2R. It is not clear if these reductions result from the blockade of one receptor or both. To determine the contribution of the two receptors, we compared the effects of Almorexant to those of the selective Ox1R antagonist ACT335827 and the selective Ox2R antagonists EMPA and TCS-OX2-29. Bicuculline (20 pmol) was injected in the perifornical hypothalamus of urethane-anaesthetized rats before and after administration of the drugs (all 15 mg/kg, intravenously). The pressor, tachycardic and tachypneic responses to bicuculline were attenuated/reduced by ACT335827 (by 19%, ns; 10%, ns and 24%, P < 0.01, respectively), EMPA (by 35% P < 0.01; 6%, ns; and 26% P < 0.05) and TCS-OX2-29 (by 13%, ns; 10%, ns and 42%, P < 0.001). These reductions represented only a fraction of the reduction after Almorexant (by 43%, P < 0.001; 42%, P < 0.001 and 65% P < 0.001). However, when the selective Ox1R and Ox2R antagonists were given in combination, the reductions were greater and closer to those of Almorexant (ACT335827 + EMPA, by 26%, P < 0.05; 24%, P < 0.05 and 47%, P < 0.001; ACT335827 + TCS-OX2-29, by 40%, P < 0.01; 26%, P < 0.001 and 59%, P < 0.0001). This was particularly clear with the tachypneic response. These results suggest that both orexin receptors contribute to the cardiorespiratory response evoked from the hypothalamus under anaesthesia. They are consistent with our previous study in the conscious animal.

Comparison of nanosecond and femtosecond pulsed laser deposition of silver nanoparticle films.

Nanoparticle (NP) films of silver were prepared using nanosecond (ns) and femtosecond (fs) pulsed laser deposition (PLD) in vacuum. The flux and energy distribution of the ions in the plasma part of the ablation plume were measured using a Langmuir ion probe. The deposition energy efficiencies of ns and fs silver PLD were also compared. For equivalent thickness up to ∼3 nm the NPs made by ns-PLD are well separated and roughly circular, but for higher thicknesses the NPs begin to coalesce. For equivalent thickness up to 7 nm the fs films are comprised of well separated NPs, though the mean NP size and the surface coverage increase with equivalent thickness. The mean Feret diameter for both ns- and fs-PLD films increases with increasing equivalent solid-density thickness. The surface plasmon resonance peak was observed to red shift for both ns- and fs-PLD films as the equivalent solid-density thickness was increased from 1 nm to 7 nm.

Reality Construction of Disaster Discourses on Twitter: Analysis of Corpus-Assisted Discourse Study on Forest Fires in Indonesia From 2014-2019.

This paper takes the form of a case study of forest fires that occurred in Indonesia from 2014 to 2019 and were reported on the social media of Twitter. The study was a corpus-assisted discourse study (CADS) using data scraping or text mining on Twitter based on the keyword "kebakaran hutan" [forest fire] and discourse analysis. The actor-network theory was used to map the actors involved. This study concludes that five discourses show a consistently large pattern of Twitter users responding to the problem of forest fires in Indonesia. Regarding the actors, the government takes an essential role of leadership and information arbitrage on Twitter. Seeing as it is the state's responsibility to ensure the safety of all people, the government must appear to be the main holder of control in managing disaster information traffic to avoid irresponsible information or hoaxes disseminated by parties or actors. These results indicate that the availability of information obtained from every conversation of Twitter users can be used as a study or input in the formulation of evidence-based policy about forest fires. It should be given more attention as an alternative means of solving the issue of forest fires, which has become an annual problem in Indonesia.

Nous rapportons ici l'étude des feux de forêts survenus en Indonésie entre 2014 et 2019, tels que rapportés sur Twitter. Nous réalisé une analyse lexicographique des tweets repérés par les mots clés « feux de forêts ¼, à partir des captures d'écran. Les acteurs impliqués ont été cartographiés selon la théorie sociologique de l'acteur-réseau. On peut alors répartir la grande majorité des utilisateurs de Twitter dans 5 catégories. Le gouvernement a des rôles d'information et de modération majeurs dans ce contexte. Ayant pour responsabilité d'assurer la sécurité de la population, il doit apparaître comme le régulateur principal du corpus de l'information, en évitant la dissémination de canulars et autres infoxes. L'ensemble des informations relayées par Twitter peut être utilisé pour construire un discours objectif qui pourrait être utilisé dans la gestion du problème des feux de forêts, qui se reproduisent chaque année en indonésie.

Voluntary exercise does not affect stress-induced tachycardia, but improves resistance to cardiac arrhythmias in rats.

1. It is currently unknown whether long-term voluntary exercise has enduring cardioprotective effects in animal models. 2. The present study was conducted in three groups of rats: (i) sedentary controls (n = 6); (ii) 24 h runners (n = 8; unlimited access to running wheels); and (iii) 2 h runners (n = 8; access to running wheels limited to 2 h daily). After termination of the 6 week exercise protocol, all rats were implanted with the telemetric electrocardiogram transmitters and were studied 1 week later. 3. Resting heart rate (HR) values in the control rats, 24 h runners and 2 h runners were 372 ± 7, 361 ± 9 and 298 ± 5 b.p.m., respectively (P < 0.05 for 2 h runners vs controls). The high-frequency spectral power in the control rats, 24 h runners and 2 h runners was 3.9 ± 0.2, 4.3 ± 0.3 and 5.3 ± 0.3 s², respectively (P < 0.05 for 2 h runners vs controls), whereas intrinsic HR was 383 ± 3, 377 ± 2 and 346 ± 3 b.p.m., respectively (P < 0.001 for 2 h runners vs controls). Restraint stress provoked tachycardia of similar magnitude in all groups. 4. After completion of telemetric studies, haemodynamic indices and susceptibility to cardiac arrhythmias were assessed in anaesthetized animals, there were no major between-group differences in HR, arterial pressure, contractility indices or sensitivity to ß-adrenoceptor stimulation (dobutamine) or blockade (atenolol). The effective refractory period in the control rats, 24 h runners and 2 h runners was 49 ± 2, 55 ± 2 and 60 ± 4 ms, respectively (P = 0.054 for 2 h runners vs controls). A significantly higher dose of aconitine was required to provoke ventricular arrhythmias in the 24 h and 2 h running groups compared with controls (489 ± 76, 505 ± 88 and 173 ± 33 µg, respectively; P < 0.05). 5. We conclude that, in rats, long-term voluntary exercise has enduring cardioprotective effects mediated at the level of both the central nervous system and the heart.

Using an Automated Algorithm to Identify Potential Drug-Induced Liver Injury Cases in a Pharmacovigilance Database.

INTRODUCTION: Drug-induced liver injury (DILI) is the most frequent cause of acute liver failure in North America and Europe, but it is often missed because of unstandardized diagnostic methods and criteria. This study aimed to develop and validate an automated algorithm to identify potential DILI cases in routine pharmacovigilance (PV) activities. METHODS: Post-marketing hepatic adverse events reported for a potentially hepatotoxic drug in a global PV database from 19 March 2017 to 18 June 2018 were assessed manually and with the automated algorithm. The algorithm provided case assessments by applying pre-specified criteria to all case data and narratives simultaneously. RESULTS: A total of 1456 cases were included for analysis and assessed manually. Sufficient data for algorithm assessment were available for 476 cases (32.7%). Of these cases, manual assessment identified 312 (65.5%) potential DILI cases while algorithm assessment identified 305 (64.1%) potential DILI cases. Comparison of manual and algorithm assessments demonstrated a sensitivity of 97.8% and a specificity of 79.3% for the algorithm. Given the prevalence of potential DILI cases in the population studied, the algorithm was calculated to have positive predictive value 56.3% and negative predictive value 99.2%. The time required for manual review compared to algorithm review suggested that application of the algorithm prior to manual screening would have resulted in a time savings of 42.2%. CONCLUSION: An automated algorithm to identify potential DILI cases was developed and successfully implemented. The algorithm demonstrated a high sensitivity, a high negative predictive value, along with significant efficiency and utility in a real-time PV database.

Crystal structures of cyclohexanone monooxygenase reveal complex domain movements and a sliding cofactor.

Cyclohexanone monooxygenase (CHMO) is a flavoprotein that carries out the archetypical Baeyer-Villiger oxidation of a variety of cyclic ketones into lactones. Using NADPH and O(2) as cosubstrates, the enzyme inserts one atom of oxygen into the substrate in a complex catalytic mechanism that involves the formation of a flavin-peroxide and Criegee intermediate. We present here the atomic structures of CHMO from an environmental Rhodococcus strain bound with FAD and NADP(+) in two distinct states, to resolutions of 2.3 and 2.2 A. The two conformations reveal domain shifts around multiple linkers and loop movements, involving conserved arginine 329 and tryptophan 492, which effect a translation of the nicotinamide resulting in a sliding cofactor. Consequently, the cofactor is ideally situated and subsequently repositioned during the catalytic cycle to first reduce the flavin and later stabilize formation of the Criegee intermediate. Concurrent movements of a loop adjacent to the active site demonstrate how this protein can effect large changes in the size and shape of the substrate binding pocket to accommodate a diverse range of substrates. Finally, the previously identified BVMO signature sequence is highlighted for its role in coordinating domain movements. Taken together, these structures provide mechanistic insights into CHMO-catalyzed Baeyer-Villiger oxidation.