Rapid Discharge Research Articles

Use of WeChat applet in the management of ambulatory surgery.

Dear Editor, Ambulatory surgery has several advantages, such as diminishing the patients’ burden, shortening the hospital stay, improving the bed turnover rate, and reducing the rate of nosocomial infection1,2. However, the accompanying issues are inevitably highlighted in the implementation of ambulatory surgery. First, the lack of effective preoperative education and preparation of patients must be seriously taken into account, as both play a pivotal role in the surgical process and contribute to a higher rate of surgery cancellations3. Moreover, proper management of discharged patients following ambulatory surgery increases the bed turnover rate4. The WeChat applet is a revolutionary yet simple application that does not require download or installation. It improves interpersonal communication between medical surgeons and patients and makes remote management more flexible and convenient. Here, we describe the development of the WeChat applet by the Ambulatory Surgery Center of the First Affiliated Hospital of Anhui Medical University (Fig. 1).Figure 1: Overview of WeChat applet. (A) The users and characteristic functions of the WeChat applet. (B) The procedure of using the WeChat applet before and after surgery.Medical counseling Patients undergoing ambulatory surgery can communicate with their attending physician before and after surgery by using one of three medical counseling methods provided by the applet. In contrast to conventional medical consultation, patients can gain access to their data, communicate with their physician, and send texts or pictures in a timely manner through the applet. Voice calls can be conveniently made through the applet, especially in cases of emergency. In addition to the above methods, the applet allows video calls for consultation on personal and complex issues. Perioperative follow-up By evaluating the patient’s general condition, the anesthesia regimen can be optimized to reduce the risks of adverse events and mortality. Although patients are unable to meet the anaesthesiologist in person, a preliminary assessment via video call through the applet can help the anaesthesiologist to understand the patient’s physical condition better and preliminarily estimate whether the patient meets the requirements of ambulatory surgery. In addition, the rapid discharge of patients following ambulatory surgery increases the difficulty of postoperative follow-up. Through the applet, patients can report their postoperative physical condition on the official follow-up form, which allows surgeons to understand better the patient’s postoperative recovery. Surgery appointment date query The applet allows the patients who meet the operation indications after the surgeon’s evaluation to schedule their ambulatory surgery at their discretion and at any time. Additionally, patients only need to enter their hospitalization number to query the surgery date, which is convenient and fast. The applet uses the cloud server to send automatic reminder notifications to the patients reminding them of their surgery date and preoperative preparation appointment. Another key function of the applet is to allow surgeons to access, display, and manage scheduled ambulatory operation information to optimize their workflow. Perioperative medical science popularization The applet allows regular posts of popular science articles related to ambulatory surgery in order to educate patients on preoperative preparation for and postoperative management following ambulatory surgery. The aim of the function is to improve patient compliance and reduce the nursing workload in the postoperative setting. Because relevant content is easily accessible via the applet, it can be reviewed repeatedly for personal reasons, thus reducing the need for repeated consultations with the surgeon. Remote ward rounds Ward rounds can be challenging because patients must be discharged within 24 h after ambulatory surgery. The applet allows surgeons to conduct ward rounds via video calls with recently discharged patients at a regular time every day, which supports better problem-solving for relevant clinical problems and ensures the safety of patients after discharge. In summary, the WeChat-based applet helps cultivate an interactive relationship between patients, surgeons, and ambulatory surgery center managers. It is a convenient method of communication that is equipped with a variety of practical yet advanced functions that can encourage the use of Connected Health in the future. Thus, we cautiously suggest that it is an advanced and practical application that can be used to benefit more patients. Ethical approval Not applicable. Sources of funding None. Author contribution H.L.: WeChat applet development, visualization, and writing – original draft, review, and editing; X.L.: writing – original draft preparation, reviewing, and editing; Y.L.: conceptualization, visualization, and writing – original draft preparation, reviewing, and editing. Conflicts of interest disclosure The authors declare that they have no conflicts of interest. Research registration unique identifying number (UIN) Name of the registry: not applicable. Unique identifying number or registration ID: not applicable. Hyperlink to your specific registration (must be publicly accessible and will be checked): not applicable. Guarantor Yao Lu. Data availability This communication article does not contain research data, so this item is not applicable.

Can a community hospital successfully transition to outpatient total knee arthroplasty in unselected patients?

BackgroundThe removal of total knee arthroplasty (TKA) from the Inpatient-Only list in 2018 created pressure on community hospitals to develop rapid discharge protocols (RAP) to increase outpatient discharge. The purpose of this study, therefore, was to compare the efficacy, safety and barriers in achieving outpatient discharge between the standard discharge protocol and newly developed RAP in unselected, unilateral TKA patients. MethodsThis retrospective chart review included 288 standard protocol patients and the first 289 RAP patients following unilateral TKA in a community hospital. The RAP focused on patient discharge expectations and post-operative patient management, with no change in post-operative nausea or pain management. Non-parametric tests were performed to compare demographics, perioperative variables and 90-readmission/complication rates between standard and RAP groups, as well as between inpatient and outpatient discharged RAP patients. Multivariate, stepwise logistic regression was performed to evaluate patient demographics and discharge status, presented as odds ratios (OR) and 95% confidence intervals (CI). ResultsDemographics were similar between groups, however, outpatient discharge significantly increased from 22.2% to 85.8% for standard discharge and RAP, respectively (p < 0.001), with no significant difference in post-operative complications. For RAP patients, age (OR:1.062, CI:1.014–1.111; p = 0.011) and female gender (OR:2.224, CI:1.042–4.832; p = 0.039) increased the risk of inpatient and 85.1% of RAP outpatients were discharged home. ConclusionsWhile RAP was successful, 15% of patients required inpatient care and 15% of patients achieving outpatient discharged were not discharged to their home environment, emphasizing the difficulties of achieving true outpatient status in 100% of patients from a community hospital.

High-Resolution Estimation of Suspended Solids and Particulate Phosphorus Using Acoustic Devices in a Hydrologically Managed Canal in South Florida, USA.

Conventional methods of measuring total suspended sediments (TSS) and total particulate phosphorus (TPP) are typically low-resolution and miss critical processes that impact their exports in aquatic environments. To create high-resolution TSS and TPP estimates, echo intensity (EI), a biproduct of velocity measurements from acoustic devices, was utilized. An acoustic Doppler velocimeter (ADV) and an acoustic Doppler current profiler (ADCP) were deployed in three locations in the L-29 Canal in South Florida, USA, to obtain estimates near the canal bed and in the water column, respectively. Corrections for transmission losses from the ADCP proved unnecessary due to the low vertical variability in the measured EI. EI calibrations were performed using artificially created TSS obtained from bed sediments (ADV) and gravimetrically measured TSS from water samples that matched the depths and times of the ADCP deployments. The measured TSS values were then analyzed for total phosphorus and converted to TPP estimates. The results showed that high TSS and TPP were caused by the rapid discharge releases typical of managed canals. This work demonstrates that high-resolution estimates are imperative for assessing the effects of such swift hydrologic changes on the potential export of sediments and nutrients to delicate ecosystems downstream.

High-Voltage Layered Manganese-Based Oxide Cathode with Excellent Rate Capability Enabled by K/F Co-doping

P-type layered manganese-based materials are prone to undergo lattice oxygen oxidation accompanied by oxygen layer slipping and even unfavorable phase transitions at around 4.2 V, giving rise to rapid discharge capacity decline and inferior structural stability, which restricts their operating voltage and energy density. Here we propose a modification strategy for layered Na0.67MnO2 material with K/F co-doping so as to reach the optimization of lattice oxygen oxidation behavior and structural stability at a high cut-off voltage of 4.4 V. Combining X-ray powder diffraction refinement results, ex situ X-ray photoelectron spectrometry analysis, high-resolution transmission electron microscopy, and electrochemical characterization, our work demonstrates that an appropriate amount of K/F co-doping has a favorable effect on the formation of well-reversible lattice oxygen oxidation behavior and the improvement of Na layer spacing. Owing to the synergetic effect of potassium and fluorine atoms, the initial discharge capacity is up to 210.2 mA h g–1 at 0.1 C and 140.2 mA h g–1 at 1 C with 73% capacity retention after 100 cycles and high discharge capacity of 115.0 mA h g–1 at 5 C, with 68.1 mA h g–1 retained after 200 cycles. The kinetic analysis shows that the optimal K0.05Na0.62MnO1.95F0.05 sample exhibits the largest sodium ion diffusion coefficient and the smallest electrochemical polarization, which paves a novel path for the application of layered manganese-based oxides in high-voltage cathode materials for sodium-ion batteries.

True "outpatient discharge" following single-stage bilateral unicompartmental knee arthroplasty may be unrealistic for most.

Single-stage bilateral unicompartmental knee arthroplasty (BUKA) has shown post-operative function and cost benefits over staged bilateral procedures, without increased complications. A rapid discharge protocol at the current study site has reported outpatient discharge for the unilateral procedure exceeding 97%. However, the feasibility of outpatient discharge following BUKA remains unclear. Therefore, the purpose of this study was to determine the success of achieving outpatient (< 24h) discharge following BUKA, and identify patient variables associated with failure. A retrospective chart review was completed for 104 BUKA patients. All patients with bilateral, symptomatic unicompartmental knee arthritis were offered the single-stage procedure. Data collection included patient demographics, discharge status, and disposition location. Independent t tests (continuous) and Chi-squared tests (categorical) determined differences between discharge (outpatient/inpatient) and disposition (home/other) groups. Variables associated with discharge status and location were assessed with multivariable regression. While 96 (92.3%) patients discharged within 24h, only 63.5% were able to discharge directly home. Patients requiring a longer hospital stay (> 24h) were more likely to require a pre-operative assistive device (62.5% and 25.0%, p = 0.037) and live alone (37.5 vs 8.3%, p = 0.033). For those discharged within 24h, living alone significantly increased the risk (odds ratio: 5.800, p = 0.038) of requiring an acute inpatient facility prior to transition home. Achieving "true" outpatient discharge is only modestly successful for most BUKA patients, as many required an acute inpatient or short-term rehabilitation facility prior to returning home. BUKA should be differentiated from the unilateral procedure regarding outpatient discharge expectations. III, Case-control study; Retrospective comparative study.

Early Naso-Gastric Feeding and Outcomes of Anorexia Nervosa Patients.

Nutritional rehabilitation with weight restoration is an important step in patients hospitalised for anorexia nervosa (AN). Naso-gastric feeding (NGF) should be considered when oral nutrition (OF) and oral nutritional supplementation (ONS) are insufficient. We evaluated the role of NGF on short- and long-term outcomes, considering weight gain, the length of hospitalisation (LOS) and the time to relapse. We report on the characteristics of patients under 18 years of age with AN admitted to the Department of Emergency and Acceptance of the Bambino Gesù Children's Hospital, IRCCS, Rome, between March 2019 and August 2022. Three hundred and fifteen patients were enrolled. We compared patients treated with NGF (group A) and patients without NGF (group B). Group A was characterised by a significantly lower BMI on admission and discharge, more frequent use of inpatient psychotropic therapy (IPDT) and longer hospital stay. The time to relapse was significantly longer in group A compared to group B. An early NGF setting correlates with a longer time to relapse and may be associated with a shorter LOS. A high caloric intake with a balanced nutritional formula provided by NGF allows an earlier recovery. The main advantages of this approach could be the rapid discharge of patients and a more effective psychological and social recovery.

Constructing graphene conductive networks in manganese vanadate as high-performance cathode for aqueous zinc-ion batteries

Aqueous zinc-ion batteries (AZIBs) have been widely studied for their cheapness, safety, as well as high energy and power density. Electrode material plays a dominant role in the electrochemical properties of zinc-ion batteries. Reduced graphene oxide (rGO) can easily interact with compounds via π-π stacking for high-speed electron transport. In this study, The Mn-modified V6O13 material cathode was uniformly loaded onto the rGO conductive network. rGO can release the electron conduction process that limits the performance of the electrode material, and improves the rapid charge and discharge performance of the material. The results show that MnVO@rGO exhibits excellent energy storage properties with a high capacity of 360.3 mAh g−1 at a current density of 0.2 A g−1 in being used as the cathode material for AZIBs. More significantly, even with a current density expansion of a factor of 100, the MnVO@rGO//Zn battery still has a capacity of 88.9 mAh g−1 and a capacity retention rate of over 100% after 10,000 cycles. In addition, it has the maximal energy density of 260.0 Wh kg−1 and power density of 9113.7 W kg−1. This study provides an interesting idea for the development of electrode materials for zinc-ion batteries.

On the concentration polarisation in molten Li salts and borate-based Li ionic liquids.

Electrolytes that transport only Li ions play a crucial role in improving rapid charge and discharge properties in Li secondary batteries. Single Li-ion conduction can be achieved via liquid materials such as Li ionic liquids containing Li+ as the only cations because solvent-free fused Li salts do not polarise in electrochemical cells, owing to the absence of neutral solvents that allow polarisation in the salt concentration and the inevitably homogeneous density in the cells under anion-blocking conditions. However, we found that borate-based Li ionic liquids induce concentration polarisation in a Li/Li symmetric cell, which results in their transference (transport) numbers under anion-blocking conditions (tabcLi) being well below unity. The electrochemical polarisation of the borate-based Li ionic liquids was attributed to an equilibrium shift caused by exchangeable B-O coordination bonds in the anions to generate Li salts and borate-ester solvents at the electrode/electrolyte interface. By comparing borate-based Li ionic liquids containing different ligands, the B-O bond strength and extent of ligand exchange were found to be directly linked to the tabcLi values. This study confirms that the presence of dynamic exchangeable bonds causes electrochemical polarisation and provides a reference for the rational molecular design of Li ionic liquids aimed at achieving single-ion conducting liquid electrolytes.

Cosa fare nella diarrea ematica? Tutto e niente?

We present the case of a 7-year-old boy with 2 days’ fever and diarrhea, who starts to present hemorrhagic diarrhea. He was evaluated in the Emergency Department and hospitalized. Campylobacter and Norovirus have been isolated on stool. During hospitalization, the patient was treated with intravenous rehydration and antipyretics, with rapid clinical improvement and discharge on the third day of hospitalization. A review of the literature shows that hemorrhagic enteritis is a frequent condition in children, with different etiologies depending on age. In children older than one year of age, the first cause is infective, of viral or bacterial origin. Generally, supportive care is sufficient in consideration of good prognosis of the infections. The use of antibiotics generally does not change outcomes; in some cases, it can even be harmful. The regional protocol for the management of hemorrhagic diarrhea in the Puglia region will be presented, with the aim of early identification of STEC infections, given their clinical relevance in the evolutionary risk of haemolytic uremic syndrome.

Interfacial effects on lithium-ion diffusion in two-dimensional lateral black phosphorus-graphene heterostructures.

Lateral heterostructures constructed from different two-dimensional (2D) materials can be potentially used in lithium-ion batteries (LIBs). The interface between two different components strongly affects LIB charge and discharge processes. Herein, the atomic structures, electronic properties, and Li-ion diffusion characteristics of lateral black phosphorus-graphene (BP-G) heterostructures are studied via first-principles calculations. The obtained results reveal that BP-G heterostructures with either zigzag (ZZ) or misoriented interfaces constructed according to Clar's rule possess a small number of interfacial states and are electronically stable. Furthermore, compared with the perfect ZZ interface of BP-G, Clar's interfaces provide a larger number of diffusion paths with much lower energy barriers. The findings of this study suggest that lateral BP-G heterostructures can provide insights for rapid charge and discharge processes in LIBs.

A theoretical study of the NbS2 monolayer as a promising anchoring material for lithium-sulfur batteries.

Developing efficient cathode materials with good conductivity to restrain the shuttle effect and promote the reaction kinetics has been a key scientific issue for the development of lithium-sulfur (Li-S) batteries. Here, by means of first-principles computations, we demonstrate that the NbS2 monolayer is a promising cathode anchoring material for Li-S batteries. It has a metallic feature that improves the conductivity of sulfur and lithium polysulfides (LiPSs) and promotes the electron transfer ability. The discharge products LiPSs are strongly anchored on the NbS2 monolayer without structural distortion, which effectively alleviates the shuttle effect. Remarkably, the reductions of sulfur to soluble LiPSs are spontaneous exothermic reactions while the subsequent reductions to insoluble LiPSs are endothermic reactions with low Gibbs free energy barriers (0.09-0.18 eV) and reaction activation barriers (0.83-0.93 eV), ensuring the rapid discharge process. In addition, the barriers of Li2S decomposition and Li atom diffusion are only 0.64 and 0.18 eV, respectively, which improve the reaction kinetics in the charging process and the cycling life of batteries. These results suggest that the NbS2 monolayer can be utilized as a promising anchoring material for Li-S batteries to achieve high reversible capacity and conversion efficiency.

Features of starting motor vehicles diesel engines with the use of molecular energy storages

Problem. With the experience of special purpose vehicles operating in the field, there is a problem of electrical start-up of diesel engines at low temperatures. It is caused by an increase in the motor oil viscosity, as well as a decrease in the starter batteries capacity. Goal. The goal of the work is to investigate the possibilities of using molecular energy storage for the reliable diesel engines start-up, including in low temperatures, aimed at improving the efficiency of the electrical start-up systems of special purpose vehicles diesel engines, which are operated in the field. Methodology. Methods of mathematical statistics were used in the study of the characteristics of molecular energy storage. When justifying the characteristics of the diesel engines electrical start-up system with molecular energy storage, mathematical methods of operations research were applied. Methods of mathematical analysis were used in the development of a diesel start-up system scheme. Results. The functional scheme of the electrical start-up system of diesel with a molecular energy storages is proposed. Originality. There are the known ways to facilitate the launch of diesel engines in low temperatures, such as the engine pre-growing or the heating of the air entering the engine combustion chambers, but they lead to a rapid discharge of starter batteries. This may make it impossible to start the diesel engine. The use of molecular energy storage will ensure a reliable start-up of a cold diesel engine. Practical meaning. The use of a combined electricity source, consisting of batteries and molecular energy storage, provides a reliable start-up of the engine in extreme temperature conditions, reducing the batteries capacity, increasing their service life, and cutting down operating costs.

Exploring the Feasibility of Mitigating Flood Hazards by an Existing Pond System in Taoyuan, Taiwan

Changes in the global climate have induced densified rainfall and caused natural hazards across the world in recent years. Formed by a central mountain range and a corridor of alluvial plains to the west, Taiwan is at risk of flood hazards owing to its low-lying lands as well as the distinct seasonality of rainfall patterns. The rapid discharge of surface runoff and a growing number of impervious surfaces have also increased flood hazards during recent typhoon landfalls. A century ago, ancestors in Taoyuan City constructed a system of water channels composed of thousands of ponds to fulfill the needs of agriculture and aquaculture. During the expansion of urban areas, land reformation replaced a majority of earlier ponds with residential and industrial zones. However, the remaining ponds could potentially serve as on-site water detention facilities under the increasing risk of floods. In this research, we first renewed an outdated pond database by deploying a novel unmanned aerial vehicle (UAV) system with a micro-sonar to map the bathymetry of 80 ponds. Next, a simplified inundation model (SPM) was used to simulate the flood extent caused by different scenarios of rainfall in Bade District of Taoyuan City. Assuming that extremely that heavy rainfalls at 25, 50, 75, and 100 mm occurred in a very short period, the flood area would decrease by 96%, 75%, 52%, and 37%, respectively, when the ponds were preparatorily emptied.

Numerical analysis of local flow heat transfer of supercritical LNG across the pseudophase transition in different airfoil channels

As the core equipment of floating storage and regasification unit (FRSU), the function of liquefied natural gas(LNG)vaporizer is to heat the LNG from -162 °C to normal temperature under supercritical pressure, which is a pseudophase transition process. This paper numerically investigates the local flow and heat transfer of supercritical LNG during the pseudophase transition process of three airfoil channels with different structures and shapes under transcritical temperature condition. The secondary flow generated by the shape and structure of the airfoil has an important influence on the local flow heat transfer performance. Especially in the liquid-like region, the three airfoil fins not only generate mixed disturbance of the velocity vector in the y-direction, but also generate secondary vortices in the z-direction, which can more effectively interfere with the boundary layer and enhance the heat transfer performance. As the temperature increases, the density and the viscosity of the supercritical LNG in the pseudo-critical and gas-like regions decrease, the vortexes formed in the three airfoil fins appear above or below the tail of the airfoil. The research shows that under the selected conditions, Fin-2 has the best hydraulic performance, especially in the gas-like region, and its f-factor can be lower than 0.02. Because Fin-2 changes the curvature of the leading edge and minimizes the impact surface, it is conducive to the rapid discharge of local fluid, thus reducing the flow resistance and generating secondary flow at the tail of the airfoil. Fin-3 has the best heat transfer performance, and its j-factor is 5–10% higher than that of other airfoil fins. This is the tail shape of the airfoil is concave, and the secondary vortices are located in the concave area, which disturbance the boundary layer and improve the heat transfer process.

Hydrodynamics of karst aquifers in metamorphic carbonate rocks: results from spring monitoring in the Apuan Alps (Tuscany, Italy)

During the last 40 years, extensive research has characterized the hydrogeology of many karst aquifers, as they are important water resources. Despite that, a systematic investigation on metamorphic karst aquifers is still lacking. The present study investigates the functioning of marble karst aquifers by means of spring hydrological monitoring, coupled with storm-hydrograph, thermograph, and chemograph (HTC) analysis and lag time analysis. Renara and Equi springs (Apuan Alps, Italy) were selected for this investigation. These springs drain catchments that have different degrees of structural complexity. Piston flow is the common hydrodynamic response of Renara spring to infiltration. Strong dilution effects were observed only during the heaviest rainfall events. Prolonged dry conditions after a sustained recharge phase showed the delayed arrival of infiltration water about a month later. Equi spring has a more complex behaviour due to its wider and more hydrologically heterogeneous catchment but the comparison of HTC graphs during the winter dry phase helped to recognize the differential contributions of proximal and distal sectors. Both springs show a rapid discharge increase in response to impulse infiltrative events. Conversely, water temperature and specific electrical conductivity increase only slightly during floods, indicating limited chemical and thermal exchanges between the rock and the water stored in these aquifers. The hydrodynamic behaviour of these karst springs suggests that the Apuan metamorphic aquifers are characterized by the predominance of conduit porosity over fissure and matrix porosities. This is explained by a reduced interstitial porosity and fracturing of the metamorphic carbonate rocks.

Contactless superconducting field exciter with active current control using hybrid magnet for high-temperature superconducting rotating machine

Rotary-type high-temperature superconducting (HTS) flux pumps using permanent magnets (PMs) are effective contactless superconducting excitation devices used for generating excitation in the field winding of HTS rotating machines. Although contactless superconducting excitation devices overcome the disadvantages of conventional contact-type excitation systems, those based on PMs are not the ideal solution because current supply to the field winding is allowed only when the HTS rotating machine is rotating in the same direction: a rapid discharge occurs when the rotation direction is reversed. They do not meet the practical operational requirements of rotating machines, viz., initial start, load fluctuation, and direction change, and alternatives to actively control excitation of field winding are essential. In this study, novel functions to improve the application feasibility in various HTS rotating machine operation modes have been proposed. Based on a numerical analysis, a prototype contactless superconducting active excitation device (CSAED) comprising PMs, alternating current (AC) and direct current (DC) electromagnets was developed using the hybrid magnet concept. The operational characteristics of active control functions in the CSAED were experimentally analysed for stationary, forward, reverse, and compensation operations of the HTS rotating machine and the qualitative effectiveness for active control of the charged current was verified. The first novel function CSAED using AC electromagnet was successfully demonstrated in initial current excitation by generating the alternating magnetic field without physical rotation for a small-scale HTS magnet. However, upgrading of the AC electromagnet is required to apply for large-scale load magnet due to small value in saturation current of the CSAED. The second novel function of CSAED using DC electromagnet worked well in current-adjustment and current-conservation modes by controlling the magnetic field density using the hybrid magnet. By controlling the current of DC electromagnets without any change in the rotation speed, the saturation current was adjusted within the ranges from 61.4 A to 1.7 A, which are 86.6 and 2.4 % of critical current for load HTS magnet, respectively. In the reverse rotation, the current discharging time of CSAED using activation of DC electromagnet increased by 2474 % compared to without energizing the DC electromagnet.

Coronary Computed Tomography Angiography for Evaluation of Chest Pain in the Emergency Department.

Coronary computed tomography angiography has emerged as an important diagnostic modality for evaluation of acute chest pain in the emergency department for patients at low to intermediate risk for acute coronary syndromes. Several clinical trials have shown excellent negative predictive value of coronary computed tomography angiography to detect obstructive coronary artery disease. Cardiac biomarkers such as troponins and creatine kinase MB, along with history, electrocardiogram, age, risk factors, troponin score, and Thrombolysis in Myocardial Infarction score should be used in conjunction with coronary computed tomography angiography for safe and rapid discharge of patients from the emergency department. Coronary computed tomography angiography along with high-sensitivity troponin assays could be effective for rapid evaluation of acute chest pain in the emergency department, but high-sensitivity troponins are not always available. Emergency department physicians are not quite comfortable making clinical decisions, especially if the coronary stenosis is in the range of 50% to 70%. In these cases, further evaluation with functional testing, such as nuclear stress testing or stress echocardiogram, is a common approach in many centers; however, newer methods such as fractional flow reserve computed tomography could be safely incorporated in coronary computed tomography angiography to help with clinical decision-making in these scenarios.

Fluorine-containing ferroelectric polymers: applications in engineering and biomedicine

Highly polar fluorine-containing ferroelectric polymers based on vinylidene fluoride refer to the class of electroactive polymers suitable for various engineering applications. Under usual crystallization conditions, polycrystalline texture is formed, while after high-voltage polarization, it is transformed into a non-centrosymmetric structure, which gives rise to high piezoelectric and pyroelectric responses. Such materials can be used for pyroelectric energy conversion. Owing to high impact strength, ferroelectric polymers can serve as materials for alternative energy sources that convert dynamic impact energy into electricity. The non-linearity of electric response (owing to ferroelectricity) and high breakdown fields offer opportunity of using them in capacitive charge storage devices. The intense dynamics of the amorphous phase provides a rapid discharge of the stored energy into an external circuit. In view of the considerable fraction of the amorphous phase ( 50%) in fluorine-containing ferroelectric polymers and high dielectric permittivity of the amorphous phase, it is possible to change the system entropy by applying an electric field. In the case of pulsed field, this provides a temperature drop; therefore, these materials (especially as composites) are promising for the design of solid-state refrigerators. The high thermoplasticity of these polymers is useful for the design of sensors &lt;i&gt;e.g.&lt;/i&gt;, microphones) with a patterned active membrane surface and enhanced characteristics. Biocompatibility and low acoustic impedance (close to the impedance of biological tissues) accounts for the possibility of using these polymers as biosensors. When domains are present in a ferroelectric film, strong local electric fields appear, which can affect the activity of living cells. Using the direct and reverse piezoelectric effect, it is possible to stimulate and control the functions of various tissues, including the nervous tissue. &lt;br&gt; The bibliography includes 463 references.

Terrestrial evidence for ocean forcing of Heinrich events and subglacial hydrologic connectivity of the Laurentide Ice Sheet.

During the last glacial period, the Laurentide Ice Sheet (LIS) underwent episodes of rapid iceberg discharge, recorded in ocean sediments as “Heinrich events” (HEs). Two competing models attempt to describe the stimulus for HEs via either internal ice sheet oscillations or external ocean-climate system forcing. We present a terrestrial record of HEs from the northeastern LIS that strongly supports ocean-climate forcing. Subglacial carbonate precipitates from Baffin Island record episodes of subglacial melting coincident with the three most recent HEs, resulting from acceleration of nearby marine-terminating ice streams. Synchronized ice stream acceleration over Baffin Island and Hudson Strait is inconsistent with internal ice sheet oscillations alone and indicates a shared ocean-climate stimulus to coordinate these different glaciological systems. Isotopic compositions of these precipitates record widespread subglacial groundwater connectivity beneath the LIS. Extensive basal melting and flushing of these aquifers during the last HE may have been a harbinger for terminal deglaciation.

Thermodynamic Interpretation of the Meyer-Neldel Rule Explains Temperature Dependence of Ion Diffusion in Silicate Glass.

We study the temperature-dependent diffusion of many types of metal and semimetal ions in soda-lime glass using thermal relaxation ion spectroscopy, a technique that provides an electrical readout of thermally activated diffusion of charge carriers driven by built-in concentration gradients and electric fields. We measure the temperature of the onset of the motion, relevant to the long term storage of radioactive elements. We demonstrate the unique behavior of silver in soda-lime glass, enabling a thermal battery with rapid discharge of stored energy above a threshold temperature. We show that the Meyer-Neldel rule applies when comparisons of temperature-dependent diffusion rates are made between related measurements on one sample or between the same measurements on related samples. The results support a thermodynamic interpretation of the Meyer-Neldel rule as an enthalpy-entropy correlation where the Meyer-Neldel temperature (T_{MN}) is the temperature that enables liquidlike, barrier-free motion of the ions, with an upper limit set by the melting point of the host medium. This interpretation explains the observed reduction in T_{MN} by built-in electric fields in depletion layers and why the upper limit for T_{MN} for all ions is set by the glass transition temperature.