Systemic Pressure Research Articles

Simultaneous stent implantation for pulmonary artery bifurcation stenosis in infants.

Pulmonary artery (PA) bifurcation stenosis often requires simultaneous stent placement, which may be technically challenging. Limited data exist regarding this practice in infants. We aim to report the procedural outcomes and safety of bifurcation stent placement in infants. We performed a single-center retrospective review of infants younger than 12 months who underwent simultaneous stent placement for PA bifurcation stenosis from January 1, 2001 through December 31, 2019. Seventeen infants underwent simultaneous PA bifurcation stent placement. The median age was 6.4 months (1.1-10.1 months), and weight was 5.8 kg (3-10.6 kg). Nine (52.9%) patients had had prior PA intervention. Most stents were placed in central PAs (28, 82.4%), followed by lobar branches (6, 17.6%). All patients received pre-mounted stents. The peak gradient across each branch decreased from 47.4 ± 16 to 18.7 ± 13 mm Hg (P less than .0001). The right ventricle to systemic systolic pressure ratio decreased from systemic (1.0 ± 0.3) to just over half systemic (0.58 ± 0.2) (P = .0001). The minimum vessel diameter increased from 3.6 ± 1.5 to 6.0 ± 1.9 mm (P less than .0001). There were 4 (23.5%) patients with high severity adverse events. There were no procedure-related deaths. The median follow-up period was 83.8 months (5.3 months-19.4 years). All patients had subsequent PA re-intervention at a median time of 8.1 months (2.9 months-8.8 years), and median time to re-operation was 19.1 months (2.9 months-7.5 years). Simultaneous PA stent placement is an effective strategy for relief of bifurcation stenosis in infants. Future transcatheter interventions are necessary to account for patient growth, but may delay the need for re-operation.

Women's Health Hubs: a rapid mixed-methods evaluation.

Women's sexual and reproductive health needs are complex and vary across the life course. They are met by a range of providers, professionals and venues. Provision is not well integrated, with inequalities in access. In some areas of the United Kingdom Women's Health Hubs have been established to improve provision, experience and outcomes for women, and to address inequalities and reduce costs. These models were established prior to the national implementation of Women's Health Hubs announced in the English 2022 Women's Health Strategy. To explore the 'current state of the art', mapping the United Kingdom landscape, and studying experiences of delivering and using Women's Health Hubs across England, defining key features and early markers of success to inform policy and practice. A mixed-methods evaluation, comprising three work packages: Mapping the Women's Health Hub landscape and context and developing a definition of Women's Health Hubs, informed by an online national survey of Women's Health Hub leaders, and interviews with regional stakeholders. In-depth evaluation in four hub sites, including interviews with staff and women, focus groups in local communities and documentary analysis. Interviews with national stakeholders and consolidation of findings from work packages 1 and 2. Fieldwork was undertaken from May 2022 to March 2023. The evaluation was initiated prior to the national scale-up of Women's Health Hubs announced in the 2022 Women's Health Strategy. Most areas of the United Kingdom did not have a Women's Health Hub. Seventeen active services were identified, established between 2001 and 2022. Women's Health Hubs were diverse, predominantly GP-led, with different perspectives of the role and definition of a hub. Women using hubs reported positive experiences, finding services caring and convenient. Implementation facilitators included committed, collaborative leaders working across boundaries, sufficient workforce capacity and a supportive policy context. Challenges included access to funding, commissioning, workforce issues, facilities and equipment, stakeholder engagement and wider system integration, priorities and pressures. Leaders were committed to addressing inequalities, but evidence of impact was still emerging. It was challenging to locate models; therefore, some may have been missed. Data availability limited assessment of impact, including inequalities. Some population groups were not represented in the data, and the evaluation was more provider-oriented. It was not possible to develop a typology of Women's Health Hubs as planned due to heterogeneity in models. Existing Women's Health Hub models were providing integrated approaches to meet local needs. Many were at an early stage of development. Evidence of system-level impact and costs was still emerging. Women's Health Hubs may widen inequalities if models are more accessible to advantaged groups. The important role of committed leaders in existing 'bottom-up' models may limit scalability and sustainability. Findings suggest that national scale-up will take time and requires funding and that it is necessary to design models according to local needs and resources. In 2023, the Department of Health and Social Care announced funding to establish a Women's Health Hub in every Integrated Care System in England. Future evaluation should consider system-level impact and costs, explore unintended consequences and test assumptions. This award was funded by the National Institute of Health and Care Research (NIHR) Health and Social Care Delivery Research programme (NIHR award ref: NIHR135589) and is published in full in Health and Social Care Delivery Research; Vol. 12, No. 30. See the NIHR Funding and Awards website for further award information.

THE EFFECT OF COMPRESSION STOCKING ON LEGS’ GEOMETRY CHANGES WITHIN DIFFERENT MOVEMENT

In this study, the changes in leg size and shape as well as pressure at different sites of a lower leg were investigated using advanced tools such as the Move4D scan system and Texsens pressure measuring device. The effect of the class of compression stocking, wearing time, and movement type was analyzed for one volunteer. It is the basis for the high-accuracy ready-to-wear compression stocking development based on the concept of personalization.

Infusion of 20% Human Albumin Reduces the Requirement of Intraoperative Intravenous Fluids in Patients Undergoing Open Gastrointestinal Oncosurgeries – A Randomised Controlled Study

Background and Aims: The optimal strategy for intraoperative fluid management in patients undergoing major abdominal oncosurgery remains undecided. The present study was undertaken to determine the effect of 20% intravenous (IV) albumin on the requirement of IV fluids (IVFs) during open gastrointestinal (GI) cancer surgeries. Methods: This randomised, double-blinded, controlled trial was conducted in a tertiary care centre from August to October 2022 after obtaining approval from the institutional ethics committee and informed written consent from the study subjects. Forty patients were randomised to either Group A (n = 20), receiving an IV infusion of 25 mL/h of 20% albumin, or Group C (n = 20), receiving an IV infusion of 25 mL/h of plasmalyte for 4 h (total 100 mL). Fluid and vasopressor administration was guided by systemic and pulse pressure variations. The primary outcome was the intraoperative requirement for IVF in the two study groups. The secondary outcomes included intraoperative IV vasopressor requirement, serum lactate levels, incidence of post-operative complications and length of hospital stay. Results: After the exclusion of three patients due to intraoperative bleeding, 37 patients were included in the final analysis. Patients in Group A (n = 19) required less IVF (3.92 ± 0.54 mL/kg/h) as compared to Group C (n = 18) (5.03 ± 1.20 mL/kg/h) (P < 0.001). Four patients (22%) in Group C required intraoperative noradrenaline IV infusion (P = 0.040). There was no significant difference between the two groups, regarding the mean intraoperative serum lactate values, incidence of post-operative complications and mean length of hospital stay (P > 0.05). Conclusions: A 100 mL of 20% human albumin as an IV infusion over 4 h reduced the requirement of IV fluid and vasopressor intraoperatively in patients undergoing open GI cancer surgery.

The oxide films formed under the low oxygen pressure in a particular system containing competing chromium and aluminium

AbstractIn this paper, pre‐oxidation treatment was carried out at 950 °C under oxygen pressure of 10−16 atm for nickel‐10 % chromium‐x % aluminium‐1 % silicon‐0.5 % yttrium(x=0 wt.–%, 1 wt.–%, 3 wt.–%, 5 wt.–%) alloys. Morphology and structure of oxide layers on the alloys after pre‐oxidation were analyzed by scanning electron microscopy and electron discharge spectroscopy. The results showed that a chromium oxide film was formed on the surface of the alloy without aluminium addition, while the oxide layer on the surface of the alloy with aluminium addition gradually transformed into M2O3 (M=aluminium and chromium) oxide film. The oxidation behavior was analyzed by means of chemical thermodynamics, and it was seen that because the interaction coefficient,εijof aluminium and chromium is a positive value, the increase of aluminium addition will strengthen the interaction and increase the diffusion coefficient,Diof aluminium and chromium. The diffusion of chromium and aluminium in each other therefore promotes their interaction, which is beneficial to the formation of the outer oxide film. Thus, with the increase of aluminium addition, the thickness of the outer oxide film gradually increased, and the aluminium content in M2O3 (M=aluminium and chromium) increased significantly, and with 5 % aluminium added, the aluminium oxide of the outer oxide film became the main body.

Study of the technical parameters dynamics influence on operational performance of hydraulic single-bucket excavators

Introduction. The development of automobile and road construction is a priority in the Russian economy. Timely putting construction projects in commission increases the requirements for planning of execution mechanized works. The operation of transport and technological machines in construction processes for a long time leads to a decrease in their potential capabilities, including operational productivity. The purpose of the proposed article is to improve the method of calculating the performance of a single-bucket hydraulic excavator (EO), taking into account the operating time.Methods and materials. The performance calculation method takes into account the dynamics of the working pressure in the hydraulic system of the working equipment (GRO), the speed of rotation of the crankshaft (PMVC) from the operating time, regression dependencies were used to describe them. The parameters of the law of distribution of the random value of the working pressure in the hydraulic drive and the rate of its fall for the ‘development and recruitment of soil’ operation were also obtained.Results. Processing of the results of production experiments enables to establish the dependence of changes in the working pressure in the hydraulic system during development and gathering soil, as well as for all technological operations of the working cycle, the rotational frequency of the crankshaft of a single-bucket excavator engine on the operating time. The influence of the working pressure in the hydraulic drive, the rotational speed of the crankshaft of the excavator engine on the supply and hydraulic power, the duration of technological operations is studied. The calculation of the operational productivity of a single-bucket excavator is carried out taking into account the dynamics of parameters reflecting its change over operating time.Discussion and conclusions. It has been established that with an increase in operating time, the operating pressure in the hydraulic drive decreases by an average of 12.7-13.0%, and the decrease in the average operating speed of the crankshaft is 4%. The estimated value of the drop in the average hourly operating performance of the EO, taking into account the deterioration of the technical condition, is 55% in the operating time range from 0 to 10,000 operating hours for the Japanese EO ZX 330 model.

Retrograde Flow to Aortic Root Predicts Inferior Cardiopulmonary Performance and Restrictive Lung Physiology in Fontan Circulation

BackgroundCardiac output in Fontan circulation depends on systemic venous pressure, pulmonary vascular resistance, and ventricular function. Because myocardial function is dependent on coronary perfusion, we studied whether retrograde flow to aortic root in the mitral/aortic atresia subgroup of hypoplastic left heart syndrome (HLHS) affects cardiopulmonary performance. MethodsWe studied 26 stable Fontan patients (14.4 ± 2.4 years) with right (RV, n = 17) and left (LV, n = 9) systemic ventricle morphology. All RV patients had HLHS and were subdivided according to postnatal flow to the hypoplastic ascending aorta being antegrade (HLHS-A) or retrograde (HLHS-R) due to valve atresia. Physical activity was assessed by questionnaire (LASERI, a questionnaire for Finnish children regarding physical activity), cardiopulmonary exercise test (1-minute ramp protocol), body composition (Biacorpus RX 4000), and muscle fitness (EUROFIT). These data were correlated with the postnatal aorta size and current branch pulmonary artery size index (McGoon index). ResultsPatients with HLHS-R seldom self-reported engagement in vigorous physical activity and had significantly lower cardiopulmonary performance (peak oxygen uptake [VO2peak]) than patients with LV morphology (P = 0.037), but not compared with patients with HLHS-A. Branch pulmonary artery size did not correlate with VO2peak. Patients with HLHS-R had most severe lung restrictions (forced vital capacity z-score –3 ± 0.9, P = 0.0073; forced expiratory volume in 1 second z-score –3.3 ± 1.1, P = 0.001). ConclusionsYoung Fontan patients with LV had better cardiopulmonary performance than patients with HLHS. Patients with HLHS-R were the least active and had the lowest VO2peak and most restrictive lungs. It is important to recognize postnatally single ventricle patients at high risk for inactivity to promote an active and healthy lifestyle.

Development of Highly Sensitive and Thermostable Microelectromechanical System Pressure Sensor Based on Array-Type Aluminum-Silicon Hybrid Structures.

In order to meet the better performance requirements of pressure detection, a microelectromechanical system (MEMS) piezoresistive pressure sensor utilizing an array-type aluminum-silicon hybrid structure with high sensitivity and low temperature drift is designed, fabricated, and characterized. Each element of the 3 × 3 sensor array has one stress-sensitive aluminum-silicon hybrid structure on the strain membrane for measuring pressure and another temperature-dependent structure outside the strain membrane for measuring temperature and temperature drift compensation. Finite-element numerical simulation has been adopted to verify that the array-type pressure sensor has an enhanced piezoresistive effect and high sensitivity, and then this sensor is fabricated based on the standard MEMS process. In order to further reduce the temperature drift, a thermodynamic control system whose heating feedback temperature is measured by the temperature-dependent structure is adopted to keep the working temperature of the sensor constant by using the PID algorithm. The experiment test results show that the average sensitivity of the proposed sensor after temperature compensation reaches 0.25 mV/ (V kPa) in the range of 0-370 kPa, the average nonlinear error is about 1.7%, and the thermal sensitivity drift coefficient (TCS) is reduced to 0.0152%FS/°C when the ambient temperature ranges from -20 °C to 50 °C. The research results may provide a useful reference for the development of a high-performance MEMS array-type pressure sensor.

The impact of refrigerant leakage on the dynamic operating performance of R600a refrigerator systems

Refrigerant leakage in refrigeration and freezing systems reduces efficiency and even results in reliable risks like insufficient cooling and component damage. This paper establishes a dynamic model of a dual-temperature zone refrigerator that combines physical and control models. It investigates the impact of refrigerant micro-leakage on the system’s dynamic operational performance, studies the effects of different leakage areas and compressor speeds on leakage performance, and identifies the critical leakage area (Ac) and critical compressor speed (Rc) based on the temperature variation patterns within the cabinets. Furthermore, this paper analyzes the coupled influence of the compressor speed and leakage area on the cabinet’s temperature. The findings reveal that after leakage occurs, the first noticeable deviations are in system pressure and the amount of refrigerant in the accumulator. Once the refrigerant in the accumulator fully vaporizes, the temperature in the cabinets is affected. Throughout the leakage process, both the system pressure and the heat exchange capacity of the evaporator decrease. At a compressor speed of 2000 rpm, the critical leakage area is 0.013 mm2, and the maximum refrigerant leakage that allows the refrigerator cabinet to cool to the shutdown temperature is 67.6 %. If the leakage area is larger than Ac, it reduces the time for alternating cooling between the freezer and refrigeration cabinets, resulting in a rapid rise in the comprehensive weighted average temperature deviation (CATD). For smaller leakage areas (<0.015 mm2), Rc exists. Operating the compressor at Rc can significantly reduce CATD. For larger leakage areas (≥0.015 mm2), Rc does not exist, increasing compressor speed has a lesser impact on CATD. The research results provide guidance for establishing a refrigerant leakage detection system and improving its accuracy, enhancing the operational reliability of refrigeration systems.

Experimental investigation on heat transfer enhancement of supercritical pressure aviation kerosene in tubular laminar flow by vibration

In advanced aero-engine thermal management systems, aviation kerosene serving as a coolant unavoidably works in a vibration environment. In this article, the laminar heat transfer performance of Chinese aviation kerosene RP-3 flowing through a horizontal micro-tube under various vibration conditions at supercritical pressures was investigated experimentally. The effects of several impact factors such as system pressure, heat flux, mass flux, inlet temperature, vibration acceleration, and vibration frequency on the heat transfer enhancement were explored in a systematic manner. Experimental results indicate that: (i) the vibration could lead to intense thermal and momentum mixing among different boundary layers of tubular laminar flow and significantly strengthens the heat transfer, and the higher Re can lead to a stronger enhancement effect. The maximum observed HTER across all experimental data is 2.8, occurring at x/d = 224.1 with the inlet temperature of 373 K; (ii) HTER hardly changes with system pressures, exhibiting a maximum relative deviation of 3.9 % at different pressures. Heat transfer enhancement has a strong dependency on heat flux, as the heat flux increases from 36 kW/m2 to 108 kW/m2, the average HTC increased by up to 36.4 %; (iii) the HTC and HTER monotonically rise with increasing vibration acceleration. Peak values in HTC and HTER are observed at vibration frequencies of 625 Hz, 191 Hz, and 242 Hz; (iv) vibration has little impact on the thermal acceleration but noticeably weakens the buoyancy close to the outlet area at high heat flux. Two well-predicted correlations for the Nu in tubular laminar flow, one with vibration and one without, are proposed.

Evaluation of the Predictive Character of the Expiratory Inferior Vena Cava/Abdominal Aorta (eIVC/Ao) Index for Minimum Blood Pressure Following Spinal Anesthesia With 0.5% Hyperbaric Bupivacaine.

Spinal anesthesia has many side effects, one of them being a drop in blood pressure (BP). Identifying predictive factors for this drop is a clear matter of concern. In this regard, the expiratory inferior vena cava/abdominal aorta (eIVC/Ao) index has already been spotted as such for doses of 0.5% hyperbaric bupivacaine greater than 12mg. Departing from the demonstrated correlation between this index and hypotension post-spinal anesthesia, our study aimed to (1) evaluate whether an eIVC/Ao index greater than 0.7, thus defining non-hypovolemic patients, can also predict minimal BP for doses inferior to 12mgand (2) identify other predictive factors for minimal BP post-spinal anesthesia. Lastly, we verified whether preoperative fasting induces hypovolemia. This single-center prospective observational pilot study included 20 patients. The baseline measurements of BP, eIVC/Ao index, and fasting time were recorded at time T0'. Then spinal anesthesia was administered with 0.5% hyperbaric bupivacaine in doses inferior to 12 mg. The patients' systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and metameric levels were each recorded at times T5', T10', T15', and T20'. The results indicated that baseline DBP was predictive of low DBP and minimum MAP, which reflect myocardial perfusion and systemic pressures, respectively. Therefore, it should trigger prophylaxis (spinal-lateralized, continuous, or lower dose) in patients with a low DBP baseline. Additionally, baseline SBP was predictive of minimumSBP, an independent risk factor for post-anesthetic hypotension if its baseline is lessthan 120 mmHg. Although female gender was linked to minimum SBP, other confounding factors (size, dose administered, and type of surgery related to gender) must also be considered. Moreover, a correlation was established between height and MAP in parturients. Hypotension was not recorded at local anesthetic (LA) doses between 8 and 12 mg and the doses administered were sufficient to achieve the metameric levels required for surgery (ether tests). Since 8 mg of 0.5% hyperbaric bupivacaine achieved the same level as 12 mg, lower doses of LA might prevent a significant drop in BP and its deleterious effects. Therefore, in the current cohort, the eIVC/Ao index was not predictive of minimum BP during spinal anesthesia with doses less than 12 mg of 0.5% hyperbaric bupivacaine. However, predictive factors for minimum BP included gender and baseline SBP (for minimum SBP), height and baseline DBP (for minimum MAP), and baseline DBP (for minimum DBP). Lastly, preoperative fasting did not cause hypovolemia.

Au-modified ceria nanozyme prevents and treats hypoxia-induced pulmonary hypertension with greatly improved enzymatic activity and safety

BackgroundDespite recent advances the prognosis of pulmonary hypertension remains poor and warrants novel therapeutic options. Extensive studies, including ours, have revealed that hypoxia-induced pulmonary hypertension is associated with high oxidative stress. Cerium oxide nanozyme or nanoparticles (CeNPs) have displayed catalytic activity mimicking both catalase and superoxide dismutase functions and have been widely used as an anti-oxidative stress approach. However, whether CeNPs can attenuate hypoxia-induced pulmonary vascular oxidative stress and pulmonary hypertension is unknown.ResultsIn this study, we designed a new ceria nanozyme or nanoparticle (AuCeNPs) exhibiting enhanced enzyme activity. The AuCeNPs significantly blunted the increase of reactive oxygen species and intracellular calcium concentration while limiting proliferation of pulmonary artery smooth muscle cells and pulmonary vasoconstriction in a model of hypoxia-induced pulmonary hypertension. In addition, the inhalation of nebulized AuCeNPs, but not CeNPs, not only prevented but also blunted hypoxia-induced pulmonary hypertension in rats. The benefits of AuCeNPs were associated with limited increase of intracellular calcium concentration as well as enhancement of extracellular calcium-sensing receptor (CaSR) activity and expression in rat pulmonary artery smooth muscle cells. Nebulised AuCeNPs showed a favorable safety profile, systemic arterial pressure, liver and kidney function, plasma Ca2+ level, and blood biochemical parameters were not affected.ConclusionWe conclude that AuCeNPs is an improved reactive oxygen species scavenger that effectively prevents and treats hypoxia-induced pulmonary hypertension.Graphical

Large area pulsed laser deposition of memristive Pr0.7Ca0.3MnO3 heterostructures for neuromorphic computing

Heterostructures of the perovskite Pr0.7Ca0.3MnO3 (PCMO) and a tunnel oxide such as AlOx are highly interesting memristive devices for emulating synaptic properties in neuromorphic circuits. Future chip generations with these memristive elements requires PLD systems which enables PCMO growth on a full wafer. To address the issue of plume broadening in this study, a slit system was used to localize the deposition region, thereby eliminating the need for excessive scanning. This study investigates the effect of the slit system and process gas pressure on plume broadening. This investigation has been used to parameterize a simulation software to assess the effectiveness of different movement speeds and to develop strategies for homogeneous deposition, adjustable to a chosen film thickness in the order of twenty nanometers. We used these strategies to fabricate area dependent switching memory cells on a standard 4″ Si wafer using the material combination of Pr0.7Ca0.3MnO3 and AlOx. The influence of the aluminum oxide thickness on the switching shows that the IV loop starts to exhibit a hysteresis for AlOx thicknesses ≥ 3 nm. An increase in AlOx thickness leads to an increase in resistance and capacitive charging. An additional thermal treatment reduces the resistance and the switching voltage and increases the ratio between low resistive and high resistive state. Devices without thermal treatment of the PCMO are compatible for back end of line processing of standard CMOS technology.

Molecular simulation to understand the effect of methane concentration and moisture contents on hydrogen adsorption in kerogens

The adsorption behaviors of methane(CH4), hydrogen(H2), and their mixtures are crucial for estimating the underground hydrogen storage(UHS) capacity in depleted shale gas reservoirs. In this study, we developed four formulated kerogen models, each representing different maturation levels of type II kerogen molecules via utilizing molecular dynamics (MD) methodologies. We investigated the adsorption characteristics of pure H2 and mixed gases(H2 and CH4) on these kerogen models with varying gas components(0.5:0.5 to 0.9:0.1) and moisture content(0–3.0 wt percentage) through grand canonical Monte Carlo(GCMC) simulations. Our findings reveal that pure H2 lacks a pressure point for adsorption equilibrium below 100 MPa at ambient temperature(298K). The competitive adsorption dynamics between H2 and CH4 on kerogen models demonstrate that CH4 exhibits stronger selectivity at lower pressures. Yet, this selectivity diminishes compared to H2 as system pressure increases, indicating turning points in pressure buildup with kerogen maturity. Additionally, the presence of pre-loading H2O molecules reduces the adsorption capacity of mixed gases, particularly affecting CH4 more than H2. This study offers profound insights into the effect of kerogen maturity and moisture content on the interaction between H2/CH4 and kerogen at a microscopic scale.

The Hemodynamic Effects of Bolus Dose Calcium in Patients Undergoing Pulmonary Artery Reconstruction and Unifocalization Surgery: A Pilot Study

Objectives: To determine if bolus administration of calcium increases pulmonary artery pressures after unifocalization procedures or pulmonary artery reconstruction surgery. Design: Retrospective cohort study using Stanford University's data warehouse. Setting: A large pediatric heart center within an academic quaternary care facility. Participants: All patients undergoing pulmonary artery reconstruction or unifocalization procedure identifiable within the data warehouse. Interventions: We collected data from Stanford University's data repository; we formatted it and analyzed it using RStudio (v 2023.06.1+524). Measurements and Main Results: Our primary outcome is the change in pulmonary artery systolic pressure (PASP) after a bolus administration of calcium. Secondary endpoints include changes in pulmonary arterial to systemic arterial pressure ratio, mean arterial pressure, right sided filling pressure, and left atrial pressure. We used the Friedman test to assess differences and the Durbin-Conover rank-sum for pairwise comparisons. We found a difference in PASP after a bolus dose of calcium (Friedman X2 = 13.67, p = 0.003), with a higher PASP five minutes after calcium administration when compared to two minutes before the administration (35 mmHg versus 33 mmHg, p = 0.01), and a higher PASP 10 minutes after calcium administration when compared to two minutes before the administration (35 mmHg versus 33 mmHg, p = 0.008). Conclusions: Calcium bolus administration led to an increase in pulmonary arterial pressure in patients after pulmonary artery reconstruction or unifocalization surgeries. It may be prudent to avoid bolus administration in this patient population immediately after repair or in patients with right ventricular dysfunction.

Pediatric hemoptysis: diagnostic and interventional challenges.

Hemoptysis in the pediatric population, while infrequent, poses significant challenges for both the family and healthcare practitioners. The severity of hemoptysis dictates management decisions. Most cases being mild and self-limiting are treated conservatively. However, "life-threatening hemoptysis" may occur, and is defined as any degree of blood loss that endangers the airway and is arbitrarily considered to be > 8ml/kg in 24h in children. It requires prompt airway management and resuscitation followed by a tailored approach consisting of bronchoscopy, computed tomography (CT), interventional radiology, and/or surgery depending on the patient 's clinical status and cardiopulmonary comorbidities. Bronchial arteries are hypertrophied in myriad conditions and account for 90-95% cases of hemoptysis due to their systemic pressure levels; the rest being contributed by pulmonary artery pathologies. Despite similar pathogenic mechanisms, the etiologies of pediatric hemoptysis differ from those in adults, with acute lower respiratory tract infections being the predominant cause. Imaging plays a crucial role in identifying the source and cause of hemorrhage. Multidetector computed tomography (MDCT) has emerged as a prime modality in the diagnostic evaluation of hemoptysis and provides a roadmap for potential interventional procedures. This article discusses the etiopathogenesis of hemoptysis along with a brief mention of the diagnostic modalities. It provides a structured reporting format and uses it to illustrate the imaging features in hemoptysis, with emphasis on CT angiography. The key findings in the lung parenchyma, airways, bronchial and non-bronchial systemic collaterals, and pulmonary arteries are elaborated upon. It further addresses the nuances of interventional management, particularly emphasizing the applications of bronchial artery embolization and pulmonary artery embolization in the pediatric population. The article also underscores the potential complications and factors influencing recurrence rates.

Physics-data fusion for digital metering of gas-liquid two-phase flow in oil nozzles

Oil well production metering is an important basis for assessing resource reserves and production capacity. Existing metering methods require high investment and involve significant implementation difficulties and high computational costs. A new method of multiphase flow metering method was proposed by combining the fluctuation of pressure drop and temperature difference generated after throttling through the oil nozzle. The throttling equation coupling differential pressure, flow rate and gas fraction was derived. By regulating the gas and liquid superficial velocity, we carried out the experimental test for true nozzle aperture of 10 mm in the loop system, covering various flow patterns. In addition, the deep neural network was constructed for inversion prediction of mass gas fraction. The proposed flow metering equation has an adaptable gas mass fraction range of 0 to 100%, unaffected by the variations in flow patterns, gas-liquid velocities, and system pressure changes. The metering errors of gas mass fraction and mass flow rate is below ±10%. The proposed metering method only relies on the existing temperature and pressure measurement system in the gathering and transportation system, and no additional measuring devices are required. It can be widely used in oil filed production to realize the virtual metering.

“GO AND GET IT CHECKED”: EXPLORING THE DECISION TO ATTEND THE EMERGENCY DEPARTMENT FOR LOW BACK PAIN

Purpose and backgroundLow back pain burdens individuals, society and services, including Emergency Departments (ED), straining services and prolonging wait times. Despite reported personal influences on deciding to attend ED, the role of third-party advice remains underexplored. Sparse guidance for clinicians and service-users highlights the need for effective back pain management strategies, to alleviate system pressure and optimise patient outcomes. This study explored how advice influences the decision to attend the ED for back pain.Methods and ResultsFrom a subtle realist stance, the design was a secondary analysis of qualitative data, where 47 patients (26M:21F, aged 23–79 years) with back pain were purposively sampled from four EDs (2 Northern and 2 Southern) in England between August and December 2021. Eight patients had previously visited ED for this episode of back pain. As this was during the pandemic, semi-structured interviews were conducted online, audio-recorded, transcribed verbatim and analysed using a reflective thematic analysis.Three themes were identified as crucial in making the decision to attend ED: The Healthcare professional; Trusted others; and the Individual. Healthcare professionals often dictated decisions, leaving participants feeling powerless. Trusted others provided varying support levels, often acting as allies. Individuals grappled with anxieties around their condition and treatment expectations.ConclusionThis study highlights the need for clinicians to provide clarity and guidance to individuals and their Trusted others, seeking advice regarding escalation to visit the ED with back pain. There was evidence that worrying about pain was a significant motivator for attending ED, resulting in malalignment with current practice guidelines.No conflicts of interest Sources of fundingFunding for primary data: Health Education England &amp; National Institute of Health and Care Research (ICA-CDRF-2018-04-ST2-040)

Comparison of the Magnesium Sulphate With Paracetamol Combination vs the Fentanyl With Lignocaine Combination in Attenuating the Hemodynamic Response During Laryngoscopy and Intubation: A Prospective, Double-Blinded Randomized Controlled Study.

Background and aims Laryngoscopy and intubation cause an increased sympatho-adrenergic pressor response, which can be detrimental to patients with coronary artery disease, hypertension, etc. Various drugs and manoeuvres have been triedto reduce the pressor response with acceptable results but the quest for the ideal drug still continues. Hence, we planned to compare the effects of magnesium sulfate with paracetamol and fentanyl with lignocaine on attenuating the hemodynamic responses due to direct laryngoscopy and intubation and to note the complications of these drugs. Methods We studied 60 adult patients of the American Society of Anaesthesiologists (ASA) physical status I and II of either sex, scheduled for elective surgery under general anaesthesia. The patients were randomly divided into two groups. Group A received 25 mg/kg magnesium sulphate mixed with paracetamol 1 gram IV (100 ml) given over 10 minutes before induction and Group B received 2 mcg/kg fentanyl and 1.5 mg/kg lignocaine, 3 minutes before intubation. All patients were uniformly pre-medicated, induced, and intubated as per standard protocol. Heart rate (HR) and systemic arterial pressures were recorded at baseline, after study drug infusion, after induction, and 1, 3, 5, 10, and 15 mins after intubation. Hemodynamic parameters were compared using repeated measures analysis of variance (ANOVA). In the post-hoc tests, p value < 0.05 was considered statistically significant. Results We observed the mean pre-op HR (p = 0.161) and mean HR one-minute post-induction (p = 0.144). The percentage change from baseline at one-minute post-induction was 9.7 in Group A and 15.2 in Group B. We observed the mean pre-op mean arterial pressure (MAP) (p = 0.119) and mean MAP one minute post-induction (p = 0.585). The percentage change from baseline at one-minute post-induction was 3.3 in Group A and 2.8 in Group B. The percentage change from baseline was found to be within 15%, for HR in Group A and for systolic blood pressure (SBP), diastolic blood pressure (DBP), and MAP in Group B. However, there was no statistically significant difference (p > 0.05) between the mean HR, SBP, DBP, and MAP between the time points. Conclusion In our study, both the combinations of drugs, magnesium sulphate with paracetamol (Group A drugs) and fentanyl with lignocaine (Group B drugs) were found to be equally effective (i.e. neither group was superior to the other) in attenuating the hemodynamic response to laryngoscopy and intubation.

A Novel Training Model for Superficial Temporal Artery- Middle Cerebral Artery Anastomosis Using Microsurgical Techniques

To create a reusable and inexpensive training model with technological tools that simulates cerebral bypass surgery and a sensor system that provides tactile feedback to the surgeon. Furthermore, we aimed to evaluate the anastomotic stability and contribution to the surgeon's learning curve. We created a superficial temporal artery-middle cerebral artery bypass simulation model using chicken and turkey brachial arteries. A cranium model was printed with a three-dimensional printer for craniotomy and cerebral parenchyma was created by pouring silicone into the cranial mold. A blood flow simulation system was also prepared. Pressure-sensitive sensors were placed on parenchyma and tactile conditioning was performed via audible warning from the sensors. Twenty-four anastomosis were performed with different sutures and hand tools. Anastomosis completion times and durability and the number of touches and pressures applied to the parenchyma were recorded. The stability of the anastomoses was evaluated by increasing the pressure in the blood flow simulation system, so usefulness of the training model was evaluated. The time required for anastomosis completion decreased as the number of practices increased (P<0.05). As the number of practices increased, the number of parenchymal touches decreased (P<0.05). With practice, the time required for anastomosis completion and number of parenchymal touches decreased. Thus, the model is useful, inexpensive, reusable, easily accessible, and contributes to the surgeon's learning curve. Our model with pressure-sensitive sensors can be used for microsurgery practice, enabling the surgeons to gain tactile conditioning and evaluate anastomotic stability and leakage.