Pressure Discrepancy Research Articles

Calibration of Cosmic Watch Desktop Muon Detector: Evaluating the Effects of Atmospheric Pressure and Material Interaction on Detection Accuracy

This study focuses on the analysis of data obtained from Cosmic Watch (CW) muon detectors. The objective is to establish a standardised procedures for the enhancement of accuracy of muon detection in varying environments. By applying correlation analysis, the linear regression line is used to addresses the impact of atmospheric pressure on muon detection rates, which is clarified in the dissertation. A significant aspect of the research involves the rectification of systematic errors, which includes inconsistencies in pressure and temporal discrepancies across groups of Cosmic Watch (CW) detectors. Furthermore, the study investigates the influence of diverse materials on muon penetration, with the detectors being covered with lead, iron, and no material, respectively. The corrected data provide more reliable detection of double- and triple-coincident events and insights into the interactions between certain material and muons. Although there are limitations, the developed calibration model provides a robust framework for future experiments involving muon detection, with potential applications in studying the properties of cosmic-ray muons, and angular distribution.

Investigating the pathophysiology and evolution of internal carotid dissection: a fluid-structure interaction simulation study.

Arterial dissection, a condition marked by the tearing of the carotid artery's inner layers, can result in varied clinical outcomes, including progression, stability, or spontaneous regression. Understanding these outcomes' underlying mechanisms is crucial for enhancing patient care, particularly with the increasing use of computer simulations in medical diagnostics and treatment planning. The aim of this study is to utilize computational analysis of blood flow and vascular wall to: (1) understand the pathophysiology of stroke-like episodes in patients with carotid artery dissection; and (2) assess the effectiveness of this method in predicting the evolution of carotid dissection. Utilizing contrast-enhanced magnetic resonance angiography (MRA), we segmented images of the patient's right internal carotid artery. These images were transformed into 3D solids for simulation in Ansys multifisic software, employing a two-way fluid structure interaction (FSI) analysis. Simulations were conducted across two wall conditions (atherosclerotic and normal) and three pressure states (hypotension, normotension, hypertension). The simulations indicated a significant pressure discrepancy between the true and false lumens of the artery. This suggests that flap motion and functional occlusion under hypertensive conditions could be the cause of the clinical episodes. Thrombotic risk and potential for dissection extension were not found to be critical concerns. However, a non-negligible risk of vessel dilation was assessed, aligning with the patient's clinical follow-up data. This study highlights specific hemodynamic parameters that could elucidate carotid artery dissection's mechanisms, offering a potential predictive tool for assessing dissection progression and informing personalized patient care strategies.

Experimental study on plunging breaking waves impacting a vertical cylinder with three different model scales

Scale effects, which can influence the reliability and effectiveness of experimental results, are often unavoidable but seldom explored, particularly in the context of plunging waves. To investigate the scale effects of plunging wave impacts on a vertical cylinder, experiments were conducted in a wave flume at model scales of 1:20, 1:30 and 1:40. The wavemaker movements were scaled based on the Froude-similarity law and the pressures on the front surface of the cylinder were analyzed. The results indicated that plunging waves were generated across these three scales, with fine agreement in overall wave elevations and a local waveform similarity of 80–90%. The analysis of pressures showed that the distribution of peak pressures on the cylinders remained consistent across different scales; however, scale effects were closely related to the intensity of wave impacts. Specifically, in cases of relatively weak impact, such as when the wavefront struck the cylinder before breaking or even after an intense wave breaking with intense gas-liquid mixtures, the pressure discrepancies were less than 20% among these different scales. This discrepancy can exceed 50% near the wave peaks during the vertical wave front or early jet formation stages with strong impacts.

Takayasu Arteritis with Congestive Heart Failure in a 16-year-old Indian Male Child

Abstract Takayasu arteritis (TA) is a rare inflammatory disease affecting medium- to large-sized vessels, notably the aorta and its branches, posing significant challenges due to arterial obstruction. We present the case of a 16-year-old Indian male with recurrent hospitalizations for congestive heart failure, eventually diagnosed with TA. Clinical examination revealed discrepancies in blood pressure, absent pulse in the left leg, and cardiovascular abnormalities. Laboratory findings indicated inflammation, and imaging confirmed arterial involvement. Treatment involved immunosuppressive therapy and symptomatic management. Despite diagnostic and therapeutic challenges, the patient showed improvement after 3 months. This case shows diverse clinical manifestations, diagnostic complexities, and the importance of a multidisciplinary approach to management. Further research is crucial in understanding mechanisms and optimizing therapeutic strategies for this rare vasculitis.

Aerodynamic discrepancies of high-speed trains meeting within two types noise barriers: considering modeling scale ratio

PurposeSustainable urban rail transit requires noise barriers. However, these barriers’ durability varies due to the differing aerodynamic impacts they experience. The purpose of this paper is to investigate the aerodynamic discrepancies of trains when they meet within two types of rectangular noise barriers: fully enclosed (FERNB) and semi-enclosed with vertical plates (SERNBVB). The research also considers the sensitivity of the scale ratio in these scenarios.Design/methodology/approachA 1:16 scaled moving model test analyzed spatiotemporal patterns and discrepancies in aerodynamic pressures during train meetings. Three-dimensional computational fluid dynamics models, with scale ratios of 1:1, 1:8 and 1:16, used the improved delayed detached eddy simulation turbulence model and slip grid technique. Comparing scale ratios on aerodynamic pressure discrepancies between the two types of noise barriers and revealing the flow field mechanism were done. The goal is to establish the relationship between aerodynamic pressure at scale and in full scale.FindingsThe aerodynamic pressure on SERNBVB is influenced by the train’s head and tail waves, whereas for FERNB, it is affected by pressure wave and head-tail waves. Notably, SERNBVB's aerodynamic pressure is more sensitive to changes in scale ratio. As the scale ratio decreases, the aerodynamic pressure on the noise barrier gradually increases.Originality/valueA train-meeting moving model test is conducted within the noise barrier. Comparison of aerodynamic discrepancies during train meets between two types of rectangular noise barriers and the relationship between the scale and the full scale are established considering the modeling scale ratio.

The effect of light massage and Spiritual Emotional Freedom Technique interventions on blood pressure among hypertension patients in Indonesia

Hypertension remains a significant global public health concern. Non-pharmacological interventions such as light massage and the Spiritual Emotional Freedom Technique (SEFT) offer potential avenues to mitigate sustained increases in blood pressure among patients with hypertension. However, research exploring these methods as alternative therapies, particularly in Indonesia, is limited. This study aimed to investigate the effects of light massage and SEFT on the blood pressure of hypertensive individuals. Employing a quasi-experimental design with a time series approach, the study utilized purposive sampling to select 27 participants. Light massage and SEFT were considered independent variables, while blood pressure served as the dependent variable. Data analysis involved repeated measures ANOVA and one-way ANOVA tests. The results revealed significant differences in mean blood pressure before and after the light massage intervention (p-values: 0.002, <0.001, <0.001). The intervention sessions yielded the most significant results (p-values: <0.001, 0.002, <0.001), whereas no differences were observed in the control group (systolic and Mean Arterial Pressure, MAP, p-values: 0.012 and 0.017, respectively). Notably, there were discrepancies in mean blood pressure before and after interventions in both the light massage and SEFT groups, indicating a potential benefit of these interventions. Conversely, no such differences were noted in the control group. These results highlight the potential benefits of integrating light massage and SEFT into holistic approaches for managing hypertension, potentially improving outcomes and quality of life for affected individuals.

Approach to Renovascular Hypertension

ABSTRACT The article describes the case of a 68-year-old man with poorly controlled hypertension, diabetes, and coronary artery disease, highlighting potential underlying causes of his condition, particularly secondary hypertension due to renal artery stenosis. His clinical evaluation reveals risk factors such as prolonged smoking, obesity, and peripheral vascular disease. Clinical examinations indicate significant blood pressure discrepancies between limbs and the presence of renal bruits, leading to the suspicion of renovascular hypertension. Resistant hypertension can often stem from renal causes, specifically atherosclerotic renal artery disease. Diagnostic approaches are detailed, including various imaging techniques and criteria for assessing renal artery stenosis. Management options are discussed, exploring both medical and interventional therapies. Although recent trials like ASTRAL, CORAL, and STAR showed limited benefits of revascularisation over medical management, selected patients may still benefit from intervention. The case underscores the importance of individualised patient evaluation for managing secondary hypertension and renovascular disease, considering both clinical presentation and renal parenchymal viability.

The relation of lactate level and carbon dioxide pressure discrepancies between transcutaneous and arterial measurements.

Partial carbondioxide pressure of the arterial blood (PaCO2) is used to evaluate alveolar ventilation. Transcutaneous carbon dioxide pressure (TcCO2) monitoring has been developed as a non-invasive (NIV) alternative to arterial blood gas analysis (ABG). Studies have shown that decreased tissue perfusion leads to increased carbondioxide (CO2). The use of transcutaneous capnometry may be unreliable in patients with perfusion abnormalities. In this study, we aimed to evaluate the relation between TcCO2-PaCO2 and lactate level which is recognized as a marker of hypoperfusion. In this prospective cohort study in critical care patients with hypercapnic respiratory failure (PaCO2 ≥45 mmHg) who received NIV between April 2019 and January 2020 in the intensive care unit were enrolled in the study. Patients' simultaneously measured TcCO2 and PaCO2 values of hypercapnic patients were recorded. Each paired measurement was categorized into two groups; normal lactate (<2 mmol/L) and increased lactate (≥2 mmol/L). A total of 116 paired TcCO2 and PaCO2 measurements of 29 patients were recorded. Bland-Altman analysis showed the mean bias between the TcCO2 and PaCO2 and 95% limits of agreement (LOA) in all measurements (1.75 mmHg 95% LOA -3.67 to 7.17); in the normal lactate group (0.66 mmHg 95% LOA -1.71 to 3.03); and in the increased lactate group (5.17 mmHg 95% LOA -1.63 to 11.97). The analysis showed a correlation between lactate level and the difference between TcCO2 and PaCO2 (r= 0.79, p< 0.001) and a negative correlation between mean blood pressure and the difference between TcCO2 and PaCO2 (r= -0.54, p= 0.001). Multiple regression analysis results showed that lactate level was independently associated with increased differences between TcCO2 and PaCO2 (Beta= 0.875, p< 0.001). TcCO2 monitoring may not be reliable in patients with increased lactate levels. TcCO2 levels should be checked by ABG analysis in these patients.

Assessment on oxidation behaviors of high chromium white iron matrix composite in high temperature air environment

Oxidation behaviors of in situ formed TiCx/high chromium white iron (TiCx/HCWI) composite containing trace alloying elements with super hardness were investigated in air at 650 °C and 700 °C for 96 h, respectively. Rich types of oxides appeared on the oxidized surfaces of the TiCx/HCWI composite both at 650 °C and 700 °C. While, MoO3 appeared on the surface only at 650 °C, FeV2O4 turned up only at 700 °C. The various oxides were enriched in diverse regions inside and outside the oxide layer at 700 °C due to the discrepancy of oxidation thermodynamics and oxidation partial pressure. Oxidation thermodynamics, kinetics, and oxidation mechanisms of the TiCx/HCWI composite were discussed. The present work provides enlightenment for the application of the super hard TiCx/HCWI.

Investigating the Bubble Point Pressure Discrepancy by History Matching for Mishrif Reservoir, Southern Iraqi Oil Field

Carbonate reservoirs have been a primary focus for academics and oil and gas companies for many years. However, the complex nature of these rocks has always posed challenges. This is particularly true in the study area, which is located in the unstable Mesopotamian Basin, where multiple oil fields produce hydrocarbons from NW-SE-trending anticlines along the Zagros Fold-Thrust Belt. The primary goal of reservoir simulation is to forecast reservoir performance and apply different techniques to improve hydrocarbon recovery under different conditions. The study area faces a problem of discrepancy in the bubble pressure at the same reservoir unit, which is attributed to the faults in the Mishrif reservoir. A study was conducted to investigate the causes of this phenomenon. The proposed method for verification involves simulating history matching using the Petrel platform after building two geological models on the probability of the fault and the reef; as a result of seismic survey interpretation. Field data for gas production of the reservoir and Pressure-Volume-Temperature analyses, especially the wells (well pad F), were used to determine the causes of the discrepancy. The current study found that the calculated and observed data match more consistently in the case of the fault rather than in the case of the reef, indicating the presence of fault in the area near the well pad F. This caused compartmentalization, leading to the discrepancy in the bubble pressure. This study could significantly improve regional exploration, especially in Iraq.

IoT-Enabled predictive maintenance for sustainable transportation fleets

This study explores the use of Internet of Things (IoT) based predictive maintenance techniques for sustainable transportation fleets. It utilizes various datasets to enhance operational efficiency and reduce environmental consequences. An examination of the fleet data uncovers interesting findings: the average mileage of the fleet is about 28,400 miles, indicating that different vehicles have been used to different extents. Notably, vehicle 002 stands out with the greatest mileage of 32,000 miles. Varying sensor measurements reveal discrepancies in tire pressure, brake pad thickness, and oil levels, suggesting different patterns of wear across the fleet. The historical maintenance data highlight the differences in maintenance intervals among automobiles. Based on predictive maintenance analysis, it is projected that vehicle 001 will need its next oil change after covering 27,000 miles, which is an increase of 2,000 miles compared to its last service. Percentage change study demonstrates the ever-changing nature of maintenance needs, highlighting the need of customized maintenance interventions that are specifically designed for each vehicle's unique characteristics. The combination of these discoveries clarifies the potential of IoT-enabled predictive maintenance in customizing tailored maintenance plans, increasing fleet efficiency, and reducing environmental impact. This research offers practical insights for adopting proactive maintenance techniques, promoting sustainability, and improving operational efficiency in transportation fleets.

Acute Obstructive Hydrocephalus and Acute Cerebellar Ischemic Stroke as a Complication of Takayasu Arteritis in a Young Male Patient: A Rare Case Report

Introduction: Takayasu arteritis is a rare type of vasculitis associated with various neurological manifestations. Multiple components, including thrombosis, embolism, stenosis, and vascular inflammation, are involved in the underlying pathophysiology. Case Presentation: A 21-year-old male patient presented with vomiting, difficulty speaking, disorientation, and seizures. On examination, pinpoint pupils and blood pressure discrepancies among four limbs were noted. Imaging findings supported the diagnosis of acute obstructive hydrocephalus, acute cerebellar infarction, and Takayasu arteritis. The patient was treated with IV antibiotics and steroids and underwent a ventriculoperitoneal shunt. Case discussion: Takayasu arteritis with cerebellar ischemia and obstructive hydrocephalus is quite a rare case. It presents with headache, dizziness, disorientation, and rarely with stroke. The diagnostic process includes computed tomography angiography (CTA) and imaging of the brain. It is mostly treated with pharmacological therapy; however, in some cases, surgery is required. Conclusion: This case highlights the rare but serious neurological adverse effects of Takayasu arteritis in young male patients, as well as the importance of interdisciplinary care. To prevent neurological degeneration, Takayasu arteritis patients must be identified and treated as soon as possible.

A case of Takayasu arteritis with normal coronary arteries presenting as stable angina

Takayasu arteritis (TAK) is a type of large vessel vasculitis characterized by granulomatous inflammation involving the aorta and its main branches. Clinical presentation may vary from non specific symptoms such as fever, malaise, weight loss to manifestations of organ hypo perfusion. Cardiac involvement may take forms of valvular insufficiency, angina or heart failure. In this case, we report a 39-year-old woman with hypertension presenting with angina, who was found to have multiple arterial bruits, with blood pressure and pulse volume discrepancies, aortic regurgitation and renovascular hypertension. She was diagnosed with Takayasu arteritis with clinical and imaging criteria; managed with glucocorticoid and DMARDS, achieving good clinical response and planned for surgical intervention for valvular insufficiency.

Carotid to subclavian bypass, rare but rewarding surgery: A case report

Different treatment options are available for subclavian stenosis (SS). Carotid to subclavian bypass surgery (CSBS) is an increasingly used effective treatment strategy when stenting is impossible. However, in Nepal, little is known about SS and its management. A 58-year-old man with a history of aortic valve replacement surgery complained of progressive left arm weakness for the past 6 months associated with pain on exertion and blood pressure discrepancies in both arms. A computed tomographic scan confirmed near-complete subclavian artery stenosis and a Doppler ultrasound showed decreased blood flow and systolic velocity. CSBS was selected as stenting was not feasible. Post-CSBS, all hemodynamic parameters returned to normal, lasting even after 2 years. CSBS appears to be a viable, safe, and promising treatment for symptomatic SS. However, additional studies need to be conducted to analyze the benefits of CSBS relative to other interventions.

Clinic furniture arrangements leading to patient self-reported blood pressure discrepancy: a rare case of total occlusion of left subclavian artery

Subclavian artery occlusion is an uncommon condition affecting approximately 2% of the general population. Only 8.7% of patients with total occlusion of subclavian artery are asymptomatic. It has the potential to cause significant morbidity as it could contribute to the ischemic complications affecting the upper extremities, brain, and heart. We present a case of asymptomatic total occlusion of left subclavian artery which was found following investigations for discrepancy in blood pressure readings from the patient’s right and left arm. The difference was noted due to the clinic’s furniture arrangement. The patient was treated with stent insertion via percutaneous transluminal angioplasty. After three years of follow ups, she remains asymptomatic and free of cardiovascular-related complications.

Discrepancy between invasive and echocardiographic transvalvular gradient after TAVI: Insights from the LAPLACE-TAVI registry

BackgroundEchocardiography-based transvalvular mean pressure gradient (ECHO-mPG) used to assess the forward valve function and structural valve deterioration could overestimate the true pressure gradient. This study evaluated the discrepancy between invasive and ECHO-mPG after transcatheter aortic valve implantation (TAVI) with respective valve type and size, its impact on a device success criterion, and predictors of a pressure discrepancy. MethodsWe analyzed 645 patients registered in a multicenter TAVI registry (balloon-expandable valve [BEV]: 500; self-expandable valve [SEV]: 145). The invasive transvalvular mPG was measured after valve implantation using two Pigtail catheters (CATH-mPG), while the ECHO-mPG was measured within 48 h after TAVI. Pressure recovery (PR) was calculated using the following formula: ECHO-mPG × effective orifice area (EOA)/ascending aortic area (AoA) × (1 − EOA/AoA). ResultsECHO-mPG was weakly correlated with (r = 0.29, p < 0.0001), and consistently overestimated CATH-mPG in both BEV and SEV, and respective valve sizes. The magnitude of the discrepancy was larger for BEV than SEV (p < 0.001) and smaller valves (p < 0.001). After the correction of PR using the above formula, the pressure discrepancy remained for BEV (p < 0.001) but not SEV (p = 0.10). The proportion of patients with an ECHO-mPG > 20 mmHg decreased from 7.0% to 1.6% after correction (p < 0.0001). Among the baseline and procedural variables, post-procedural ejection fraction, BEV versus SEV, and smaller valves were associated with a larger discrepancy in mPG. ConclusionsECHO-mPG could be overestimated after TAVI, especially in patients with a smaller BEV. A higher ejection fraction, BEV, and smaller valves were predictors of a pressure discrepancy between CATH- and ECHO-mPG.

OA35 Early identification of large vessel vasculitis: a specific benefit of a non-specific symptom pathway?

Abstract Background/Aims Since December 2020 in Cornwall there has been a Non-Specific Symptom Pathway (NSSP): a 2-week-wait pathway by which GPs can access a CT thorax, abdomen &amp; pelvis (CT-TAP) to assess non-specific symptoms where there is a suspicion of malignancy, but conventional 2-week-wait referral criteria are not met. An unexpected consequence of this pathway was the finding of cases of suspected large vessel vasculitis (LVV) being referred to rheumatology outpatients. Methods Cases with a new diagnosis of LVV or cancer were identified using the NSSP database over the period of December 2021- May 2022. Clinical and laboratory features were analysed and compared. During this time period a Logiq E10 US machine was acquired by the department, enabling axillary US to be performed for some of the suspected LVV cases that were referred to rheumatology. Results Of the 241 accepted referrals, 14 patients (5.81%) had a subsequent definite cancer diagnosis, 6 (2.49%) had LVV diagnosed as a direct consequence of the NSSP. 5 (83%) cases of LVV had CRP &amp;gt;60 versus 4 (33%) of the cancer patients where measured. Mean CRP was 38.9 in cancer patients and 82.3 in LVV (normal 0-5mg/L). Mean platelet count was 401 in cancer patients, 510 in LVV patients (normal 150-400x109). 3 LVV patients had immunoglobulins and serum protein electrophoresis tested, of which 2 had significantly raised IgG and 1 was confirmed as polyclonal. In one case, significant thoracic aneurysmal dilatation was identified; a 59-year-old previously healthy woman presented to primary care with fatigue, night sweats and arm pain. Investigations showed anaemia, thrombocytosis, polyclonal high immunoglobulins, CRP 74. CT-TAP via NSSP revealed thoracic aorta wall thickening with aneurysmal dilatation, diameter being 4.5cm at the aortic arch. Subsequently the patient was referred to vascular surgeons and rheumatology. Rheumatology clinic review noted no symptoms of cranial giant cell arteritis or polymyalgia rheumatica. Examination revealed significant blood pressure discrepancy between right and left arms (diastolic difference of 62mmHg) and bilateral axillary bruits. Bilateral axillary artery ultrasound revealed significant intima-media thickening: right distal 1.19mm, left distal 1.37mm (normal less than 0.9mm) consistent with LVV. 10mg Prednisolone and subsequently leflunomide 10mg were initiated with resolution of inflammatory markers and symptoms. Surgical intervention was not felt to be required but regular surveillance continues. Conclusion Polyclonal raised IgG, unexplained raised CRP and thrombocytosis, arm blood pressure discrepancy and axillary bruits may be useful indicator tests for referral to the NSSP. LVV diagnosis normally requires extensive inpatient investigations in patients with pyrexia-of-unknown-origin and can be challenging in the absence of PMR or cranial GCA symptoms. As well as early identification of cancer, NSSP has the additional benefit of detecting cases of LVV that may have otherwise gone unnoticed, including the cases with secondary aneurysmal change. Disclosure R. Machin: None. M. Hughes: None.

Experimental study on dynamic pressure under the crest of unidirectional nonlinear waves

The dynamic pressure under wave crests is experimentally studied in three different scenarios, and the influence of nonlinearity as well as the dispersive effect is revealed by comparing with the corresponding linear theoretical predictions. For regular waves, the nonlinear effect plays different roles in modifying the upper and lower sections of the dynamic pressure under the wave crests with the boundary determined by the strength of nonlinearity. Regarding irregular waves, the dynamic pressure under wave crests is mainly affected by the surrounding individual waves within the same wave group, and in most cases its variation is dominated by the dispersive effect, exhibiting a greater magnitude than its counterpart in regular waves. As to focused waves, the same large crests can be realized in the time domain with different methods, but the discrepancy of dynamic pressure is very noticeable due to the fundamentally different nonlinearities involved in the focusing process. Therefore, to accurately evaluate the dynamic pressure under wave crests in the ocean, the dominant nonlinearity at the current evolutionary stage, as well as the dispersive effect, must be considered.

Gas separation simulation based on ab initio and variable soft sphere model in ratchet-shaped microchannels

A technique for the separation of rarefied gas mixtures based on microelectromechanical systems (MEMS) has recently attracted the attention of researchers. The mechanism of gas separation is the thermally induced flow caused by inhomogeneous temperature gradients within the microchannel, which distinguishes the velocity of different gas species. In this paper, the effects of Knudsen number Kn and equilibrium temperature T0 on the flow properties of each gas species within the gas mixture, such as velocity, molar fraction, streamlines, temperature, and pressure, are investigated by the Direct simulation Monte Carlo (DSMC) method. The flow of the gas mixture is numerically simulated using a quantum scattering-based ab initio (AI) potential and compared with the results of numerical simulations based on the variable soft sphere (VSS) model. The results show that the gas velocity accelerates with increasing temperature, but decreases with increasing Knudsen number. The streamlines are very sensitive to the Knudsen number, yet they are only affected by the temperature in the transitional flow. When the conditions are the same, He flows faster than Ne and the streamlines are smoother. The gas separation factor increases with equilibrium temperature at T0<100K and decreases slightly with equilibrium temperature at T0≥100K. The gas separation efficiency is best in the transitional flow. The temperature discrepancy for the different gas species is less affected by the equilibrium temperature and Knudsen number, with the maximum discrepancy rate being only 2.727% for He and Ne. The pressure discrepancy is more affected by the equilibrium temperature and Knudsen number, with the maximum rate of discrepancy reaching 39.228% for He and Ne. At T0=10K and Kn=1, the discrepancy rates of the gas separation factor, temperature, and pressure obtained based on the AI potential and the VSS model reach maximum values of 44.802%, 4.675%, and 52.716%, respectively. Compared to the VSS model, the AI potential based on quantum scattering is applicable to a wider range of temperatures and is more accurate for both low and high temperatures. Furthermore, the AI potential is more accurate than the VSS model in the transitional flow. The results obtained from the AI potential based on quantum scattering will be more desirable when performing gas separation studies based on thermally induced flows in rarefied gases.

Anesthetic implications for transurethral resection of prostate in a COVID-19 survivor with Stanford-A aortic dissection with acute urinary retention due to metastatic carcinoma prostate: a case report

BackgroundAortic dissection is a new addition to the long COVID-19 complication catalog. We report this rare and novel complication, which can be missed without a high index of suspicion in the ever-burgeoning population of COVID-survivors presenting for un-related surgery. We emphasize the importance of recording blood pressure in both the upper limbs in COVID-survivors during pre-anesthetic checkup, especially in patients with a dilated aorta on the chest radiograph to identify any interarm blood pressure discrepancy characteristic of aortic dissection. Discontinuation of antihypertensive based on low/normal blood pressure in left upper limb can precipitate concealed and catastrophic rise in blood pressure in the right upper-limb propagating the dissection of aorta to a fatal conclusion. The cardinal anesthetic consideration is to mitigate the effect of hemodynamic perturbations on the dissected aorta.Case presentationWe report the successful management of the case of a 76-year-old male prostatic cancer patient with COVID-induced aortic-dissection and acute urinary retention, posted for transurethral resection of prostate. CT angiography revealed an intimal flap in the ascending aortic lumen and aortic arch till the origin of left subclavian artery resulting in a double-barreled aorta. An arterial line was secured in right radial artery and non-invasive blood pressure recorded in left arm simultaneously (202/60 mmHg in right upper-limb and 92/70 mmHg in the left upper-limb on wheeling into the operation theatre). He underwent transurethral prostatic resection and bilateral orchidectomy under low-dose subarachnoid block with prophylactic use of labetalol infusion.ConclusionsThe importance of recording blood pressure in both the upper limbs in COVID survivors maintaining a high index of suspicion for aortic dissection cannot be overemphasized. Transurethral prostatic resection surgery under low-dose subarachnoid block is possible under the umbrella of judicious selection and optimal use of cardiac medication with an interventional cardiologist as standby in patients with aortic dissection.