Potential Discharge Research Articles

Drivers of global irrigation expansion: the role of discrete global grid choice

Abstract. Global statistical irrigation modeling relies on geospatial data and traditionally adopts a discrete global grid based on longitude–latitude reference. However, this system introduces area distortion, which may lead to biased results. We propose using the ISEA3H geodesic grid based on hexagonal cells, enabling efficient and distortion-free representation of spherical data. To understand the impact of discrete global grid choice, we employ a non-parametric statistical framework, utilizing random forest methods, to identify the main drivers of historical global irrigation expansion using, among other data, outputs from the global dynamic vegetation model Lund-Potsdam-Jena managed Land (LPJml). Irrigation is critical for food security amidst growing populations, changing consumption patterns, and climate change. It significantly boosts crop yields but also alters the water cycle and global water resources. Understanding past irrigation expansion and its drivers is vital for global change research, resource assessment, and the prediction of future trends. We compare predictive accuracy, simulated irrigation patterns, and identification of irrigation drivers between the two grid systems. Using the ISEA3H geodesic grid system increases the predictive accuracy by up to 28 % compared to the longitude–latitude grid. The model identifies population density, potential productivity increase, evaporation, precipitation, and water discharge as key drivers of historical global irrigation expansion. Gross domestic product (GDP) per capita also shows some influence. We conclude that the geodesic discrete global grid system significantly affects predicted irrigation patterns and identification of drivers and thus has the potential to enhance statistical modeling, which warrants further exploration in future research across related fields. This analysis lays the foundation for comprehending historical global irrigation expansion.

Activation of mouse skin mast cells and cutaneous afferent C-fiber subtypes by bee venom

In mammals, many Hymenopteran stings are characterized by pain, redness, and swelling − three manifestations consistent with nociceptive nerve fiber activation. The effect of a Western honeybee (Apis mellifera) venom on the activation of sensory C-fibers in mouse skin was studied using an innervated isolated mouse skin preparation that allows for intra-arterial delivery of chemicals to the nerve terminals in the skin. Our data show that honeybee venom stimulated mouse cutaneous nociceptive-like C-fibers, with an intensity (action potential discharge frequency) similar to that seen with a maximally-effective concentration of capsaicin. The venom had a stronger effect on chloroquine-sensitive C-fibers compared to chloroquine-insensitive C-fibers, an effect that was recapitulated with a wasp (Vespula spp.) venom. Blocking TRPV1 and TRPA1 channels did not influence the honeybee venom-induced C-fiber activation. The effect of the venoms on chloroquine-sensitive and −insensitive subpopulation of C-fiber terminals was mimicked by melittin but not apamin; two of peptide venom components. Chloroquine-sensitive C-fibers are stimulated as a consequence of mast cell activation. Melittin degranulated mast cells in mouse skin by a non-IgE and non-MrgprB2 mechanism, and this may explain the stronger activation of the chloroquine-sensitive C-fibers.

Desorption of Antibiotics from Granular Activated Carbon during Water Treatment by Adsorption

Although desorption of adsorbed pharmaceuticals from granular activated carbon (GAC) may inadvertently lead to their partial discharge with adverse effects on aquatic environments, there have only been a few reports of this phenomenon. This study has investigated desorption of antibiotics vancomycin and rifampicin from activated carbon in aqueous media regarding contact time and pH regime. Various characterizations of the three types of GAC were investigated. Then, antibiotics were loaded on them via adsorption. Subsequently desorption and re-adsorption of antibiotics were quantified for a range of contact times and ambient pH values. Within the first hour of a reversed concentration gradient at neutral pH, desorption released 2% to 54% of previously adsorbed antibiotics to water, which were subsequently re-adsorbed within 24 hours to four weeks with less than 1% antibiotics remaining in the liquid phase. Lower desorption was positively associated with higher GAC mesopore content and larger specific surface area. Effects of the ambient pH regime varied between studied adsorbents. The results are evidence that mesopore content and pore size in relation to the kinetic diameter of adsorbate molecules are important determinants of the extent of antibiotic desorption from GAC and the rates of subsequent re-adsorption. Physisorption was the dominant mechanism involved in both processes. Observed proportions and rates of antibiotic desorption suggest that selection of GAC properties should also consider their effects on unintended desorption and the re-adsorption during treatment processes in order to minimize potential pollution discharge or promotion of antibiotic resistance during treatment processes.

Simple Model for Discharge of Lithium Battery

Abstract Shell-progressive framework was applied to lithium ion battery to arrive at a simple analytic relationship for the discharge of the battery. The relationship provides the depth of discharge as a function of time with a coefficient involving physical properties and another representing potential discharge capacity, given the discharge rate and the state of charge in the previous charge-discharge cycle. Also derived is a relationship between the discharge time and the current, which can be used as an alternative to Peukert’s law. The results should be useful for assessing the discharge behavior and for designing the electrode.

Analysis of the Physical and Chemical Composition of Sludge from the Water Treatment Plant

The properties and composition of the sludge generated in water treatment systems depend primarily on the type and composition of the water to be treated, the treatment methods, and the type and doses of chemical reactants. The sludge produced in the water treatment plant (WTP) under study follows the technological processes of coagulation, flocculation, sedimentation, and filtration. The analyses aimed to characterize the sludge in terms of its physico-chemical properties and classify it in terms of its potential discharge into the river and management. Four series of sediment tests were conducted over a calendar year (March, June, September and December), analysing selected parameters using various test methods, including the X-ray crystallography (XRF) method. The publication's authors showed that the sediment consists mainly of sand, clay, and silt particles with grain sizes ranging from 0.001 mm to 1 mm. Silica (53.78%), alumina (23.58%), calcium oxide (8.28%), iron (III) oxide (5.61%), and potassium oxide (2.36%) represent the main chemical constituents present in the sediment. The authors characterized the sediment in terms of the content of biogenic compounds: various forms of phosphorus and nitrogen, organic compounds – determined as total organic carbon (TOC), selected metals, and the content of individual elements (carbon, hydrogen, oxygen, nitrogen, sulfur). In addition, the sludge samples were also characterized in terms of calorific value, ash content, water content, and heat of combustion. Discharging WTP sludge into rivers, ponds, and lakes or storing dewatered sludge is an environmentally unfriendly form of disposal for this type of waste. The authors see the possibility of conducting further research on using WTP sludge in wastewater treatment, removing heavy metals from aqueous solutions, producing cement and construction materials, and recovering or recycling.

Human sympathetic neuronal discharge and recruitment patterns regulate neuropeptide Y bioavailability.

What is the purpose of sympathetic neuronal action potential (AP) discharge and recruitment patterns for human vascular regulation? This study tested the hypothesis that sympathetic neuronal discharge and recruitment patterns regulate neuropeptide Y (NPY) bioavailability. We used microneurography to record muscle sympathetic nerve activity (MSNA) and a continuous wavelet transform to detect sympathetic APs during a baseline condition and intravenous dexmedetomidine infusion (α2-adrenergic agonist, 10 min loading infusion of 0.225 µg kg-1; maintenance infusion of 0.1-0.5 µg kg h-1) in six healthy individuals (5 females, 27 ± 6 years). Arterial blood samples provided NPY (enzyme-linked immunosorbent assay) and norepinephrine (Liquid Chromatography Tandem Mass Spectrometry) levels during baseline and the dexmedetomidine maintenance infusion. Linear mixed model regressions assessed the relationships between AP discharge, recruitment, and neurotransmitter levels. Across baseline and the dexmedetomidine condition, NPY levels were positively related to mean arterial pressure (β = 1.63 [0.34], P = 0.002), total AP clusters (β = 0.90 [0.22], P = 0.005), and AP frequency (β = 0.11 [0.03], P = 0.003). Norepinephrine levels were not related to mean arterial pressure (β = 0.03 [0.02], P = 0.133) but were positively related to total AP clusters (β = 19.50 [7.07], P = 0.030) and AP frequency (β = 2.66 [0.81], P = 0.014). These data suggest that sympathetic neuronal discharge and recruitment patterns regulate NPY and norepinephrine bioavailability in healthy adults. As such, sympathetic neuronal firing strategies are important for human vascular regulation.

Analysis of nerve excitability in the dentate gyrus of the hippocampus in cerebral ischaemia-reperfusion mice

Ischemic stroke often leads to cognitive dysfunction, which delays the recovery process of patients. However, its pathogenesis is not yet clear. In this study, the cerebral ischemia-reperfusion model was built as the experimental object, and the hippocampal dentate gyrus (DG) was the target brain area. TTC staining was used to evaluate the degree of cerebral infarction, and nerve cell membrane potentials and local field potentials (LFPs) signals were collected to explore the mechanism of cognitive impairment in ischemia-reperfusion mice. The results showed that the infarcted area on the right side of the brain of the mice in the model group was white. The resting membrane potential, the number of action potential discharges, the post-hyperpolarization potential and the maximum ascending slope of the hippocampal DG nerve cells in the model mice were significantly lower than those in the control group ( P < 0.01); the peak time, half-wave width, threshold and maximum descending slope of the action potential were significantly higher than those in the control group ( P < 0.01). The time-frequency energy values of LFPs signals in the θ and γ bands of mice in the ischemia and reperfusion groups were significantly reduced ( P < 0.01), and the time-frequency energy values in the reperfusion group were increased compared with the ischemia group ( P < 0.01). The signal complexity of LFPs in the ischemia and reperfusion group was significantly reduced ( P < 0.05), and the signal complexity in the reperfusion group was increased compared with the ischemia group ( P < 0.05). In summary, cerebral ischemia-reperfusion reduced the excitability of nerve cells in the DG area of the mouse hippocampus; cerebral ischemia reduced the discharge activity and signal complexity of nerve cells, and the electrophysiological indicators recovered after reperfusion, but it failed to reach the healthy state during the experiment period.

MEASUREMENT OF WATER DISCHARGE OF SAKARTEMEN RIVER TO IDENTIFY POTENTIAL OF MICRO HYDRO POWER PLANT IN FAKFAK REGENCY

Fakfak Regency, West Papua Province is one of the oldest regencies in Papua. However, electricity problems are still a scourge that has not yet been resolved properly. So far, the mainstay of power plants in Fakfak Regency is the Diesel Power Plant (PLTD) which is highly dependent on the supply of Fuel Oil (BBM) and the reliability of the Diesel Engine. In fact, Fuel Oil (BBM) is one of the natural resources that cannot be renewed. For this reason, it is necessary to conduct a study on New Renewable Energy (EBT) that has the potential to be developed in Fakfak Regency. There are several rivers that have the potential to be developed as Micro Hydro Power Plants (PLTMH) in Fakfak Regency. The existence of Micro Hydro Power Plants (PLTMH) in Fakfak Regency is one of the real solutions to the power outages that still often occur in Fakfak Regency. Through this study, it is hoped that there will be a mapping of the energy potential that can be produced by several rivers in Fakfak Regency if used as Micro Hydro Power Plants (PLTMH). In addition, the potential of Micro Hydro Power Plant (PLTMH) will support the transition of power plants in Fakfak Regency. Another objective is to support environmental conservation efforts (nature and culture) and increase community participation in the management of existing natural resources, thus providing economic benefits to the local community. The research was conducted through surveys and direct measurements where the measurement results will be calculated to determine the potential river flow discharge and the potential for power generation. The results of the measurements and calculations obtained an average discharge of the Sakartemen River of 3.1m3/second which based on the measurement of the effective fall height (Heff) of the flow was obtained at 4 m. With these results, it can be estimated that the electrical power generated is 104,260 kW.

Differences in subcortical functional connectivity in patients with epilepsy.

Epilepsy is a disease characterized by abnormal paroxysmal bioelectrical activity in the brain cortex and subcortical structures. Seizures per se change brain metabolism in epileptic focus and in distal parts of the brain. However, interictal phenomena can also affect functional connectivity (FC) and brain metabolism in other parts of the brain. We hypothesised that epilepsy affects functional connectivity not only among cortical, but also between subcortical, structures of the brain in a resting state condition. Investigating functional connectivity in patients with epilepsy could provide insights into the underlying pathophysiological mechanisms. Better understanding may lead to more effective treatment strategies. Functional connectivity was analysed in 35 patients with epilepsy and in 28 healthy volunteers. The group of patients was divided into generalised and focal epilepsy (temporal and extratemporal subgroups). Each patient and healthy volunteer underwent an fMRI resting-state session. During the study, EEG signals were simultaneously recorded with fMRI to facilitate the subsequent detection of potential interictal epileptiform discharges (IEDs). Their potential impact on BOLD signals was mitigated through linear regression. The data was processed and correlation coefficients (FC values) between the BOLD signal from selected structures of the central nervous system were determined and compared between study groups. The results were presented as significant differences in correlation coefficients between brain/subcortical structures in the epilepsy and control groups. Lower FC values for the epilepsy group compared to the control group were shown for connections related to the MPFC, hippocampus, thalamus, amygdala, and the parahippocampal gyrus. Epilepsy alters the functional connectivity of resting state subcortical networks. Patterns of pathological changes of FC differ between epilepsy subtypes, with predominant lower FC between the hippocampus, parahippocampal gyrus, amygdala and thalamus in patients with epilepsy. This study suggests that epilepsy affects subcortical structures. Identifying distinct patterns of altered FC in epilepsy subtypes may help to tailor treatment strategies. Changes in FC detected by fMRI may precede clinical symptoms, aiding in the early diagnosis of cognitive and emotional disorders in focal epilepsy.

Decomposition characteristics and influencing mechanisms of C4F7N/CO2 gas with different metal materials

C4F7N/CO2 gas mixture, as the main new environmentally friendly gas insulation medium, is now being widely used in the ring network switchgear and other gas electrical equipment. In this paper, a test platform was constructed to simulate partial discharge in a gas medium, the decomposition characteristics of the C4F7N/CO2 gas mixture during suspended potential discharge were studied under four different metal electrode materials: stainless steel, purple copper, tungsten copper, and aluminum alloy. The results show that the main decomposition products of the C4F7N/CO2 gas mixture during suspended discharge are CO, CF4, C4F8, C3F8, C3F6, CF3CN, and C2F4 gases, which are independent of the metal material. On the whole, when the metal electrode material is stainless steel, the highest amount of decomposition products are generated from the C4F7N/CO2 gas mixture; when the metal electrode material is aluminum alloy, the amount of decomposition products produced by C4F7N/CO2 gas mixture is the least, and the content difference of some decomposition products between these two metal materials is as high as 70%. The decomposition products of the C4F7N/CO2 gas mixture decreased gradually with the increase in the gas pressure. Finally, the influence mechanism of different metal materials on the decomposition process of the C4F7N/CO2 gas mixture was analyzed from the microscopic perspectives of charge transfer between gas molecules and molecular structural characteristics. In general, the research results can provide technical reference for the design, selection, and optimization of environmental protection gas insulation equipment.

Functional and Structural Investigation of Myenteric Neurons in the Human Colon

Background and aimsThe enteric nervous system independently controls gastrointestinal function including motility, which is primarily mediated by the myenteric plexus, therefore also playing a crucial role in functional intestinal disorders. Live recordings from human myenteric neurons proved to be challenging due to technical difficulties. Using the neuroimaging technique, we are able to record human colonic myenteric neuronal activity and investigate their functional properties in a large cohort of patients. MethodsActivity from myenteric neurons in wholemount preparations of different sampling sites of fresh, human colonic tissue was recorded using neuroimaging with the voltage sensitive dye Di-8-ANEPPS. Neuronal responses were analysed following stimulation with nicotine and serotonin (5-HT) for differences based on the donor’s age, the disorder indicative for surgery and the colonic region. Immunohistochemistry was performed to calculate the total neuronal numbers. ResultsStimulation with nicotine and 5-HT elicited reproducible action potential discharge in a proportion of human myenteric neurons. The responses to 5-HT were significantly greater in tissues from older patients and from those with inflammatory disorders, while neuronal activity to nicotinergic stimulation was comparable in all patients. Neuronal numbers declined with rising patient’s age and was highest in the sigmoid colon. ConclusionNeuroimaging with Di-8-ANEPPS was successfully adapted to record reproducible responses from human colonic myenteric neurons upon pharmacological stimulation. Evidence exists for an impact of age and inflammation on the serotonergic neuronal signalling and for differences in neuronal numbers in the distinct colonic regions as well as a neuronal decrease with age.

Central α2-adrenergic mechanisms regulate human sympathetic neuronal discharge strategies.

The present study investigated the impact of central α2-adrenergic mechanisms on sympathetic action potential (AP) discharge, recruitment and latency strategies. We used the microneurographic technique to record muscle sympathetic nerve activity and a continuous wavelet transform to investigate postganglionic sympathetic AP firing during a baseline condition and an infusion of a α2-adrenergic receptor agonist, dexmedetomidine (10min loading infusion of 0.225µgkg-1; maintenance infusion of 0.1-0.5µgkgh-1) in eight healthy individuals (28±7years, five females). Dexmedetomidine reduced mean pressure (92±7 to 80±8mmHg, P < 0.001) but did not alter heart rate (61±13 to 60±14bpm; P=0.748). Dexmedetomidine reduced sympathetic AP discharge (126±73 to 27±24 AP100 beats-1, P=0.003) most strongly for medium-sized APs (normalized cluster 2: 21±10 to 5±5 AP100 beats-1; P < 0.001). Dexmedetomidine progressively de-recruited sympathetic APs beginning with the largest AP clusters (12±3 to 7±2 clusters, P=0.002). Despite de-recruiting large AP clusters with shorter latencies, dexmedetomidine reduced AP latency across remaining clusters (1.18±0.12 to 1.13±0.13s, P=0.002). A subset of six participants performed a Valsalva manoeuvre (20s, 40mmHg) during baseline and the dexmedetomidine infusion. Compared to baseline, AP discharge (Δ361±292 to Δ113±155 AP100 beats-1, P=0.011) and AP cluster recruitment elicited by the Valsalva manoeuvre were lower during dexmedetomidine (Δ2±1 to Δ0±2 AP clusters, P=0.041). The reduction in sympathetic AP latency elicited by the Valsalva manoeuvre was not affected by dexmedetomidine (Δ-0.09±0.07 to Δ-0.07±0.14s, P=0.606). Dexmedetomidine reduced baroreflex gain, most strongly for medium-sized APs (normalized cluster 2: -6.0±5 to -1.6±2 %mmHg-1; P=0.008). These data suggest that α2-adrenergic mechanisms within the central nervous system modulate sympathetic postganglionic neuronal discharge, recruitment and latency strategies in humans. KEY POINTS: Sympathetic postganglionic neuronal subpopulations innervating the human circulation exhibit complex patterns of discharge, recruitment and latency. However, the central neural mechanisms governing sympathetic postganglionic discharge remain unclear. This microneurographic study investigated the impact of a dexmedetomidine infusion (α2-adrenergic receptor agonist) on muscle sympathetic postganglionic action potential (AP) discharge, recruitment and latency patterns. Dexmedetomidine infusion inhibited the recruitment of large and fast conducting sympathetic APs and attenuated the discharge of medium sized sympathetic APs that fired during resting conditions and the Valsalva manoeuvre. Dexmedetomidine infusion elicited shorter sympathetic AP latencies during resting conditions but did not affect the reductions in latency that occurred during the Valsalva manoeuvre. These data suggest that α2-adrenergic mechanisms within the central nervous system modulate sympathetic postganglionic neuronal discharge, recruitment and latency strategies in humans.

Rethinking hospital postoperative resource use: A national analysis of pediatric appendectomy patients admitted to children’s hospitals

BackgroundThe increased use of remote monitoring and telemedicine support may help alleviate the need for some of the postoperative inpatient hospital care and reduce health care costs, but little is known about current postoperative hospital resource use patterns. We aim to describe hospital resources use patterns in pediatric patients postappendectomy for complicated appendicitis and to evaluate the potential of earlier discharge with remote monitoring. MethodsThis was a retrospective cohort study using the Pediatric Health Information System database for patients who underwent laparoscopic appendectomy for complicated appendicitis between 2016 and 2021. Health care use/costs (antibiotics, intravenous fluids [proxy for diet], analgesics, laboratory studies, and imaging tests) were determined using administrative billing data. Potentially avoidable days were defined as nondischarge days without codes for intravenous opioid pain medication or intravenous fluids. Descriptive statistics and logistic regression were used. ResultsIn total, 24,165 patients were included: 8,300 patients (34.3%) had at least 1 potentially avoidable hospitalization day, totaling 13,970 days or 14.2% of all hospitalization days. Median hospitalization cost was $19,434 [$15,658–$25,157], with accommodation and operating room being the greatest contributors. Public insurance and minority races and ethnicities were associated with greater odds of potentially avoidable days. More than 80% of hospitalized patients had intravenous antibiotics through 10 days postoperatively. More than 20% received opioids daily. ConclusionsMore than one third of the patients who underwent laparoscopic appendectomy for complicated appendicitis could have had at least 1 potentially avoidable hospitalization day. Remote monitoring and telemedicine support should be explored and could help with earlier discharge and lower costs.

Induction of long-term hyperexcitability by memory-related cAMP signaling in isolated nociceptor cell bodies.

Persistent hyperactivity of nociceptors is known to contribute significantly to long-lasting sensitization and ongoing pain in many clinical conditions. It is often assumed that nociceptor hyperactivity is mainly driven by continuing stimulation from inflammatory mediators. We have tested an additional possibility: that persistent increases in excitability promoting hyperactivity can be induced by a prototypical cellular signaling pathway long known to induce late-phase long-term potentiation (LTP) of synapses in brain regions involved in memory formation. This cAMP-PKA-CREB-gene transcription-protein synthesis pathway was tested using whole-cell current clamp methods on small dissociated sensory neurons (primarily nociceptors) from dorsal root ganglia (DRGs) excised from previously uninjured ("naïve") rats. Six-hour treatment with the specific Gαs-coupled 5-HT4 receptor agonist, prucalopride, or with the adenylyl cyclase activator, forskolin, induced long-term hyperexcitability (LTH) in DRG neurons that manifested 12-24 hours later as action potential (AP) discharge (ongoing activity, OA) during artificial depolarization to -45 mV, a membrane potential that is normally subthreshold for AP generation. Prucalopride treatment also induced significant long-lasting depolarization of resting membrane potential (from -69 to -66 mV), enhanced depolarizing spontaneous fluctuations (DSFs) of membrane potential, and indications of reduced AP threshold and rheobase. LTH was prevented by co-treatment of prucalopride with inhibitors of PKA, CREB, gene transcription, and protein synthesis. As in the induction of synaptic memory, many other cellular signals are likely to be involved. However, the discovery that this prototypical memory induction pathway can induce nociceptor LTH, along with reports that cAMP signaling and CREB activity in DRGs can induce hyperalgesic priming, suggest that early, temporary, cAMP-induced transcriptional and translational mechanisms can induce nociceptor LTH that might last for long periods. An interesting possibility is that these mechanisms can also be reactivated by re-exposure to inflammatory mediators such as serotonin during subsequent challenges to bodily integrity, "reconsolidating" the cellular memory and thereby extending the duration of persistent nociceptor hyperexcitability.

Induction of long-term hyperexcitability by memory-related cAMP signaling in isolated nociceptor cell bodies

Persistent hyperactivity of nociceptors is known to contribute significantly to long-lasting sensitization and ongoing pain in many clinical conditions. It is often assumed that nociceptor hyperactivity is mainly driven by continuing stimulation from inflammatory mediators. We have tested an additional possibility: that persistent increases in excitability promoting hyperactivity can be induced by a prototypical cellular signaling pathway long known to induce late-phase long-term potentiation (LTP) of synapses in brain regions involved in memory formation. This cAMP-PKA-CREB-gene transcription-protein synthesis pathway was tested using whole-cell current clamp methods on small dissociated sensory neurons (primarily nociceptors) from dorsal root ganglia (DRGs) excised from previously uninjured (“naïve”) male rats. Six-hour treatment with the specific Gαs-coupled 5-HT4 receptor agonist, prucalopride, or with the adenylyl cyclase activator forskolin induced long-term hyperexcitability (LTH) in DRG neurons that manifested 12–24 h later as action potential (AP) discharge (ongoing activity, OA) during artificial depolarization to −45 mV, a membrane potential that is normally subthreshold for AP generation. Prucalopride treatment also induced significant long-lasting depolarization of resting membrane potential (from −69 to −66 mV), enhanced depolarizing spontaneous fluctuations (DSFs) of membrane potential, and produced trends for reduced AP threshold and rheobase. LTH was prevented by co-treatment of prucalopride with inhibitors of PKA, CREB, gene transcription, or protein synthesis. As in the induction of synaptic memory, many other cellular signals are likely to be involved. However, the discovery that this prototypical memory induction pathway can induce nociceptor LTH, along with reports that cAMP signaling and CREB activity in DRGs can induce hyperalgesic priming, suggest that early, temporary, cAMP-induced transcriptional and translational mechanisms can induce nociceptor LTH that might last for long periods. The present results also raise the question of whether reactivation of primed signaling mechanisms by re-exposure to inflammatory mediators linked to cAMP synthesis during subsequent challenges to bodily integrity can “reconsolidate” nociceptor memory, extending the duration of persistent hyperexcitability.

Expediting Discharges on the Inpatient Medicine Teaching Services

Introduction: Delayed discharges can adversely affect patient flow throughout the hospital. Late afternoon discharges may lead to high hospital occupancy, admission bottlenecks, ER overcrowding, and disrupted ICU transfers. Discharge by noon (DBN) is key to enhancing hospital capacity, bed utilization, and patient satisfaction and outcomes. Last year, DBN for patients returning home with or without home care services (HHC) was chosen as one of three annual priorities for our hospital medicine division. This was implemented in October 2023 but did not gain momentum among the medical resident teaching services (MTS), paving the way for our QI project. Model for Improvement: Baseline data on the percentage of MTS DBN to home and HHC were available from November 2023 to January 2024. We surveyed our residents/faculty and conducted a root-cause analysis. The main barriers to DBN included a lack of planning and motivation, delayed communication with case management, and prolonged rounding. Aims Statement: Our goal was to increase the median percentage of MTS discharge orders placed by noon to home and HHC from 22% to 35% within 3 months. Measures: Our primary outcome measure was the percentage of MTS DBN to home and HHC. Weekly EMR-generated reports were collected. The outcome measure was then calculated and uploaded weekly on a run chart for analysis. Qualitative process measures included assessing if residents were planning discharges and documenting the number of discharges completed before noon. Changes: Our interventions targeted the lack of planning and motivation. These included introducing the expedited initiative and its importance to residents/faculty through conferences. In addition, a process was created where potential next-day discharges were discussed at afternoon sign-out and a tracking chart of DBN orders was designed for each team room. Tests of Change: Our pre-intervention median percentage of MTS DMB to home and HHC was 22% and improved to 40% post-intervention. While we observed a variation in discharge practice based on the rounding attending, we had notably sustained an upward shift in practice from our baseline when data was plotted on a run chart. We are currently continuing data collection to track sustainability and variability among rounding physicians. Conclusion: We attained an upward shift in the percentage of MTS DBN to home and HHC post-intervention. Although an upward shift has been achieved, we are looking to sustain and further improve it. In future PDSA cycles, we will look at individualizing feedback and optimizing interdisciplinary rounds. We plan on further investigating balancing measures such as bed availability, discharge timing for rehabilitation destinations, and patient and staff satisfaction.

Alternative end-of-life options for disposable bioplastic products: Degradation and ecotoxicity assessment in compost and soil

Four different end-of-life options for disposable bioplastic cups were investigated and compared based on their environmental implications. Two products with distinct polymeric composition were tested simulating the following scenarios at laboratory scale: i) industrial composting (180 days at 58 °C); ii) anaerobic digestion followed by industrial composting (45 days at 55 °C and 180 days at 58 °C); iii) anaerobic digestion followed by direct digestate use on soil for agricultural purposes (45 days at 55 °C and 180 days at 25 °C); iv) uncontrolled release into a soil environment (180 days at 25 °C). Ecotoxicity tests were run at the end of each experiment to investigate the effects of the materials on three main groups of terrestrial model organisms: plants, earthworms and nitrifying bacteria. Complete biodegradation of the cups was observed in 180 days in the scenarios involving composting environment. A low degree of biodegradation (22.9 ± 4.5%) of the digestates in soil was observed, warning for a potential micro-bioplastics discharge into the environment. No degradation was observed for the cups in soil during the same testing period. Ecotoxicity tests revealed a negative effect on plants biomass growth across all samples, which was 17–30% lower compared to the blank sample. The experimental campaign highlighted the need for a systematic assessment of controlled treatment of bioplastics, as well as the need for a harmonized legislative framework.

A comparison of wavelet-based action potential detection from the NeuroAmp and the Iowa Bioengineering Nerve Traffic Analysis system.

Microneurographic recordings of muscle sympathetic nerve activity (MSNA) reflect postganglionic sympathetic axonal activity directed toward the skeletal muscle vasculature. Recordings are typically evaluated for spontaneous bursts of MSNA; however, the filtering and integration of raw neurograms to obtain multiunit bursts conceals the underlying c-fiber discharge behavior. The continuous wavelet transform with matched mother wavelet has permitted the assessment of action potential discharge patterns, but this approach uses a mother wavelet optimized for an amplifier that is no longer commercially available (University of Iowa Bioengineering Nerve Traffic Analysis System; Iowa NTA). The aim of this project was to determine the morphology and action potential detection performance of mother wavelets created from the commercially available NeuroAmp (ADinstruments), from distinct laboratories, compared with a mother wavelet generated from the Iowa NTA. Four optimized mother wavelets were generated in a two-phase iterative process from independent datasets, collected by separate laboratories (one Iowa NTA, three NeuroAmp). Action potential extraction performance of each mother wavelet was compared for each of the NeuroAmp-based datasets. The total number of detected action potentials was not significantly different across wavelets. However, the predictive value of action potential detection was reduced when the Iowa NTA wavelet was used to detect action potentials in NeuroAmp data, but not different across NeuroAmp wavelets. To standardize approaches, we recommend a NeuroAmp-optimized mother wavelet be used for the evaluation of sympathetic action potential discharge behavior when microneurographic data are collected with this system.NEW & NOTEWORTHY The morphology of custom mother wavelets produced across laboratories using the NeuroAmp was highly similar, but distinct from the University of Iowa Bioengineering Nerve Traffic Analysis System. Although the number of action potentials detected was similar between collection systems and mother wavelets, the predictive value differed. Our data suggest action potential analysis using the continuous wavelet transform requires a mother wavelet optimized for the collection system.

Chronic intermittent hypoxia (CIH) enhances nTS sensitivity to oxytocin (OT) and corticotropin-releasing hormone (CRH) via effects at the nTS soma and on presynaptic release

OT and CRH neurons from the hypothalamus project to nucleus tractus solitarii (nTS) to influence its activity and response to hypoxia. CIH increases sympathetic nervous system activity, blood pressure, and respiration, and the nTS contributes to these responses. Yet, the influence of these OT or CRH inputs on nTS activity during CIH is unclear. We hypothesized that OT or CRH individually increases nTS activity, and their combined influence would further enhance activity. We also expected these responses to be enhanced by CIH. Male Sprague-Dawley rats (~3 wks) were exposed to 10d normoxia (21% O2) or CIH (~30s of 6% O2, 10x/hr, 8 h/day). Recorded events were examined during exogenous OT and CRH or their receptor block (OTR-x, CRHR2-x). As a time control, aCSF only was examined, which did not alter any events over the 40-min recording period. In nTS slices, extracellular neuronal discharge from multielectrode array recording was increased by OT and its co-application with CRH throughout the nTS after normoxia. Following CIH, OT and CRH alone, and their co-application increased firing rate, and the response to OT+CRH after CIH was greater than in normoxia slices. Fura-2 calcium imaging in dissociated nTS neurons demonstrated enhanced responses to OT+ CRH following CIH vs normoxia. In second-order nTS neurons recorded via patch clamp, OT and CRH induced spontaneous action potential discharge after CIH in quiescent neurons during baseline periods. Excitatory postsynaptic currents (EPSCs) were recorded to examine synaptic transmission. Spontaneous (s)EPSCs were not altered by OT and CRH after normoxia or CIH. Yet, only after CIH OTR-x and/or CRHR2-x reduced sEPSC amplitude, indicating tonic activation of these receptors maintain current amplitude. Afferent (TS)-EPSCs evoked at 0.5 and 20 Hz were not altered by OT and CRH or their receptor blockers in normoxia. However, CIH elevated TS-EPSCs in response to CRH and CRH+OT. Block of OTR and CRHR2 after CIH did not alter TS-EPSC amplitude, indicating their minimal tonic influence on sensory integration. After a 20Hz stimulation, the peak of asynchronous EPSCs increased in presence of CRH and OT+CRH only after CIH. We examined presynaptic Ca2+ in pre-labeled GCaMP6m afferent terminals in response to a 20 Hz stimulation. In normoxia-exposed slices, OT and CRH increased Ca2+ fluorescence. However, after CIH, the application of CRH and the co-application of OT+CRH decreased the terminal Ca2+ response. The expression of OT but not CRH fibers within the nTS decreased (immunohistochemistry) while OTR and CRHR2 mRNA increased (RNA Scope). The CRH and OT neuron populations within PVN were not altered after CIH (immunohistochemistry). Altogether, our data show that following CIH, OT and CRH augment neuronal activity via postsynaptic mechanisms while CRH also increases synaptic transmission through enhancing presynaptic release. Those alterations may contribute to elevated sympathetic response and blood pressure observed after CIH. NIH R01 HL098602 &amp; R01 HL128454 (DDK). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

P058 A service evaluation of rheumatologist-led ultrasound clinics at a tertiary care centre

Abstract Background/Aims Rheumatologist-led ultrasound (USG) clinics were established at UCLH over 10 years ago with an intention to improve speed of diagnosis and/or execution of treatment plan with the benefit of clinical assessment and diagnostic imaging in one appointment. The benefits for patients may include reduced time taken from work and reduced anxiety. This project aimed to evaluate reasons for referral to this clinic, the outcome of a patient review and the impact of this service. Methods Retrospective Health-record data were collected from EPIC using Google forms for patients who had USG of their hands in the specialist clinics for 3 months (Jan - March 2022). Data included patient demographics, clinical data, USG findings, intended change or initiation of treatment, and outcome of the review. Results 54 patients had been reviewed in the three months. More than half (61%) were referred to help answer a treatment-related question and the remaining were to confirm diagnosis (39%). Most patients referred for diagnosis had their diagnosis confirmed (86%). Majority (62%) also had appropriate follow up and two were discharged; a further six had potential to be discharged at this time. Out of the 33 referred for treatment questions, there were 23(70%) patients who needed no change to their treatment; 15(65%) of these would have potentially been initiated on biologics otherwise. This resulted in potential savings of between £76,497-£107,601 per 6-month (trial of DMARD) period due to drug cost. Table 1 lists potential indirect savings. Conclusion This service evaluation found considerable direct and indirect savings that emphasises the need for such specialist service in the cost-strapped NHS. The direct cost savings relate to the drugs that were not required to be initiated, with the majority attributed to the avoidance of biologics. In addition to the indirect cost savings to the NHS , the reduction of risk to the patient of unnecessary immunosuppression remains undefined. As a result of this service evaluation, to enhance potential discharges from this clinic, referring clinicians manage patient expectations at referral and communicatepotential for discharge at referral to the scanning clinician. Disclosure A. Zmuda: None. J. Manson: None. M. Castelino: None.