Risk Of Failure Research Articles

Analysis and Validation of a Diagnostic Nomogram for Predicting the Risk of Acute Respiratory Failure for Non-HIV Related Pneumocystis Jirovecii Pneumonia Patients.

Pneumocystis Pneumonia (PCP), primarily affecting individuals with weakened immune systems, is a severe respiratory infection caused by pneumocystis jirovecii and can lead to acute respiratory failure (ARF). In this article, we explore the risk factors of ARF and propose a prognostic model of ARF for PCP patients. In this multi-center, retrospective study in 6secondary or tertiary academic hospitals in China, 120 PCP patients were screened from the Dryad database for the development of a predictive model. A total of 49 patients from Peking University People's Hospital were collected for external validation. Crucial clinical features of these patients are selected applying univariate and multivariate logistic regression analysis. We established an intuitive nomogram. Receiver operating characteristic (ROC) curve, calibration curve, decision curve analysis (DCA) and clinical impact curve (CIC) were plotted to evaluate the model's performance. A cohort of 120 patients formed the training cohort for the development of the model, with 49 patients constituting the test cohort. Univariate and multivariate logistic regression analysis identified five risk factors associated with ARF, which are age, fever, dyspnea, high neutrophil count and use of antibiotics. A nomogram was then proposed based on these factors. The area under the ROC curve (AUROC) in the development group has reached 0.8576, while the validation group has an AUROC of 0.7372, indicating commendable ability for predicting ARF. In addition, results for Hosmer-Lemeshow test indicate the effectiveness of our model. Furthermore, DCA and CIC curves demonstrate excellent clinical benefit. We present a nomogram for predicting ARF in non-HIV related PCP patients. The prognostic model may provide references in clinical medicine, promote timely treatment and improve therapeutic outcomes of PCP patients.

Comparative analysis of deep learning models for various nonalcoholic fatty liver disease datasets

Fatty liver disease is caused by increased liver buildup or weight above 5-10%. This disorder is widespread in people with diabetes, overweight persons, and metabolic syndrome patients. Clinical decision support systems can improve liver failure diagnosis and prediction to reduce this situation. Many liver failure models have drawbacks, and liver failure prediction is still a problem. This work uses four large open-access critical care patient datasets to create and verify liver failure risk prediction models. This study aims to construct a clinically applicable diagnostic and predictive model that evaluates the probability or risk of liver failure in intensive care unit (ICU) patients using extreme gradient boosting (XGBoost), artificial neural networks (ANN), multi-layer perceptron (MLP), Modular Neural Network (MNN), and generalized feed forward (GFF). We evaluated performance metrics using these models: accuracy, sensitivity, specificity, and predictive accuracy.

Failure mechanism and risk decision-making process of frozen soil wall for blocking nuclear contaminated water leakage: A laboratory study

Failure mechanism and risk decision-making process of frozen soil wall for blocking nuclear contaminated water leakage: A laboratory study

Evolution of residual stress of SiCf/Ti17 composites at high temperature evaluated by micro-Raman spectroscopy

SiCf/Ti17 composites are considered promising lightweight high-temperature structural materials for the aerospace field due to their excellent mechanical properties. However, during the manufacturing process, differences in the coefficients of thermal expansion between various material components inevitably generate thermal residual stresses at the interfaces. These thermal residual stresses can lead to stress concentration and other failure modes, thereby affecting the mechanical properties of SiCf/Ti17 composites. Therefore, it is crucial to systematically study the residual stresses in the interfacial C coating and the W/SiC interfacial regions, as well as the evolution of these stresses at high temperatures. In this study, samples were first subjected to vacuum heat treatment, followed by systematic micro-Raman experiments conducted radially on the fibers. Subsequently, the Raman spectra were subjected to peak deconvolution to obtain precise target peaks. By combining Raman peak shifts with Hooke's law, the evolution of high temperature residual stresses in the C coating and W/SiC interfacial regions were determined. Additionally, changes in the Raman spectral data at different temperatures were analyzed to investigate the variations in the micro-composition of different regions. The results showed that at 850°C, both the C coating and the W/SiC interfacial region exhibited good mechanical properties and strength retention. However, at 1050°C, the mechanical properties of both regions gradually deteriorated, with the W/SiC interfacial region showing a sharp increase in compressive stress. At this point, the SiCf/Ti17 composite material may face a risk of failure.

Coupling effects of loading rate and temperature on mode I dynamic fracture characteristics of ductile cast iron

Engineering structures made of ductile cast iron (DCI) have a potential risk of failure due to extreme service environments such as high velocity impacts and sub-zero temperatures. Therefore, it is of great importance to investigate the dynamic fracture behavior of DCI under the coupling effect of rate and temperature. In this paper, two sets of impact velocities (5 m/s and 13.5 m/s), and four sets of temperatures (20 °C, −40 °C, −60 °C, and −80 °C) were specially designed to investigate the coupling effect on the mode I dynamic fracture toughness (DFT). The results show that DFT is positively correlated with impact velocity at 20 °C, −40 °C and −60 °C. However, at −80 °C, the rate effect is reversed. Moreover, DFT decreases with decreasing temperature regardless of impact velocity. With microscopic analysis, the phenomenon of ductile–brittle transition (DBT) was observed in the failure of the material, and it’s verified by dynamic tensile tests. The ductile–brittle transition temperature (DBTT) of DCI is determined as −39.7 °C by comparing the DFT with the strain energy density (SED) characterization method.

Cost-effectiveness of viral load testing for transitioning antiretroviral therapy-experienced children to dolutegravir in South Africa: a modelling analysis

For children with HIV on antiretroviral therapy (ART), transitioning to dolutegravir-containing regimens is recommended. The aim of this study was to assess whether introducing viral load testing to inform new nucleoside or nucleotide reverse transcriptase inhibitors (NRTIs) for children with HIV and viraemia alongside dolutegravir-based ART is beneficial and of good economic value. We used the Cost-Effectiveness of Preventing AIDS Complications-Pediatric model to project clinical and cost implications of three strategies among a simulated cohort of South African children aged 8 years with HIV receiving abacavir-lamivudine-efavirenz: (1) continue current ART (no dolutegravir; abacavir-lamivudine-efavirenz); (2) transition all children with HIV to dolutegravir, keeping current NRTIs (dolutegravir; abacavir-lamivudine-dolutegravir); or (3) transition to dolutegravir based on viral load testing (viral load plus dolutegravir), keeping current NRTIs if virologically suppressed (abacavir-lamivudine-dolutegravir, 70% of cohort) or switching abacavir to zidovudine (zidovudine) if viraemic (zidovudine-lamivudine-dolutegravir, 30%). We assumed 50% of children who had viraemia after abacavir-lamivudine exposure had NRTI resistance; with resistance, we assumed zidovudine-lamivudine-dolutegravir was more effective than abacavir-lamivudine-dolutegravir. We designated a strategy as preferred if it was most effective and least costly or had an incremental cost-effectiveness ratio less than half the South African 2020 gross domestic product per capita. Under base-case assumptions, the viral load plus dolutegravir strategy would be the most effective (projected undiscounted life expectancy of 39·72 life-years) and least costly strategy (US$24 600 per person); the no dolutegravir strategy was the least effective (34·49 life-years) and most expensive ($26 480 per person). In sensitivity analyses, the 24-week virological suppression probability and subsequent monthly virological failure risks (ie, late failure) were most influential on cost-effectiveness. Only with a high late-failure risk for zidovudine-lamivudine-dolutegravir (ie, ≥0·3% per month in the base case or >0·5% per month if abacavir also confers low virological suppression probability in the presence of NRTI resistance [65%]) would the dolutegravir strategy become preferred above the viral load plus dolutegravir strategy. For programmes transitioning to dolutegravir-based regimens, our model predicted that doing so would be more effective and less costly than continuing current ART regimens, regardless of NRTI choice. Whether viral load testing for children with HIV is necessary to inform NRTI choice depends substantially on the comparative outcomes of abacavir and zidovudine after switching to dolutegravir-containing ART. The Eunice Kennedy Shriver Institute for Child Health and Human Development, the National Institute of Allergy and Infectious Diseases, the Massachusetts General Hospital Executive Committee on Research, the Massachusetts General Hospital, and the Medical Research Council.

Association of care specialty with anticoagulant prescription and clinical outcomes in newly diagnosed atrial fibrillation: Results from the GARFIELD-AF registry

ObjectiveTo determine whether stroke prevention strategy, comorbidity management, and clinical outcome risks differ across atrial fibrillation (AF) care specialties. MethodsNewly diagnosed non-valvular AF patients enrolled in the international, prospective GARFIELD-AF registry (enrolment: 2010–2016) were analysed. Prescription of oral anticoagulation (OAC) therapy and select comorbidities was assessed by baseline care specialty: cardiology, primary care, or other specialties (internist/neurologist/geriatrician). Associations between care specialty and 2-year clinical outcomes were evaluated using multivariable Cox frailty models to account for within-country homogeneity. ResultsIn 52,011 patients, 34,172 (65.7 %) were diagnosed and initially managed in cardiology care, 7396 (14.2 %) in primary care, and 10,443 (20.1 %) in other specialties. The inter-country care specialty distribution varied considerably. Non-vitamin K OAC (NOAC) therapy among CHA2DS2-VASc ≥2 patients was more common in cardiology care (31.0 %) than primary care (19.8 %) and other specialty care (24.9 %), but comorbidity management was similar across specialties. Compared to cardiology care, primary care was associated with greater non-cardiovascular mortality (1.21 [1.01–1.45]), major bleeding (1.31 [1.05–1.62]), and new/worsening heart failure risk (2.09 [1.69–2.59]). Care in other specialties was associated with greater all-cause (adjusted hazard ratio, 1.19 [95 % CI, 1.09–1.29]), cardiovascular (1.15 [1.01–1.31]), and non-cardiovascular mortality (1.29 [1.13–1.47]), as well as non-haemorrhagic stroke/systemic embolism (1.48 [1.26–1.73]), major bleeding (1.21 [1.02–1.43]), and new/worsening heart failure risk (1.45 [1.21–1.75]) than cardiology care. ConclusionComorbidity management was similar across AF care specialties, but patients outside of cardiology care had fewer NOAC prescriptions and greater risk for most clinical endpoints. Cardiology expertise may have important implications for AF prognosis.Clinical trial registration: URL: http://www.clinicaltrials.gov. Unique identifier for GARFIELD-AF: NCT01090362

Braking failure anti-rollover control and hardware-in-the-loop verification of wire-controlled heavy vehicles

Considering the fault tolerance of EMB (Electro-Mechanical-Brake) braking failure and anti-rollover control at the same time is one of the urgent problems to be solved in the driving safety of X-by-wire vehicles. Accurate rollover index is a key part of anti-rollover control. Aiming at the problem that the traditional rollover index reflects that the unsprung mass of the vehicle is insufficiently affected by road excitation, a tripped vehicle rollover dynamic model is established based on single-wheel braking failure, and a rollover evaluation index NLTR (New Load-Transfer-Rate) suitable for braking failure is proposed. In order to improve the lateral safety of the vehicle when the line control fails, a hierarchical anti-rollover controller based on road adhesion coefficient identification, SM-ABS (Sliding-Mode-ABS) control and DBR (Differential-Braking-Redistribution) control is designed. Taking the rollover index threshold as the controller trigger condition, the controller effects under NLTR, traditional RI2 and standard LTR indicators are compared respectively. Simulation and HIL test show that the traditional index controller has failure risk under extreme conditions. The designed NLTR index controller can accurately evaluate the rollover risk of the vehicle, control the vehicle in time, and improve the vehicle stability by 68.18% under Fish-Hook condition.

Pemodelan Degradasi dan Agradasi Dasar Sungai dengan Beberapa Persamaan di Sungai Winongo Yogyakarta

Calculating riverbed degradation and aggradation is essential in designing riverbank protection structures, particularly for determining foundation depth. Excessive degradation can compromise foundation stability, significantly increasing the risk of structural failure. Numerous predictive models for egradation and aggradation have been developed by researchers, highlighting the importance of selecting an equation that closely aligns with the specific characteristics of the river to achieve optimal design accuracy. This study aims to determine the most suitable predictive model for riverbed degradation and aggradation. A case study was conducted along a 43.75 km of the Winongo River Yogyakarta. The simulation involved riverbed sediment data collected at 500 m intervals from upstream to downstream, and secondary discharge data comprising average daily discharge for both wet and dry months. The selected grainsize parameter follows standards in HEC-RAS 6.3.1, with the Meyer Peter Müller equation applied to d90, Engelund Hansen to d50, and Laursen Copeland to d84. Simulation results of riverbed degradation were then compared against observed conditions of riverbank erosion. Riverbank steepness or protective structure failure indicates excessive riverbed degradation, while stable conditions suggest otherwise. Based on the simulations conducted on the Winongo River, the Engelund Hansen equation provided average degradation estimates more consistent with field conditions than the other two equations.Keywords: degradation and agradation, transport sediment equations, HEC-RAS, river bank

Numerical investigation on failure modes and TDA-based mitigation measure of jointed rigid pipes under ground subsidence

Jointed rigid pipes are vulnerable to permanent ground deformation (PGD). Compressible and lightweight materials, such as tire-derived aggregate (TDA), geofoams and straws, can be placed around buried pipes to reduce the loads from PGD and minimize the risk of pipe failures. In this study, a calibrated three-dimensional finite element model incorporating a modified Mohr-Coulomb model for simulating the strain softening behavior of surrounding soils is employed to analyze the failure modes of jointed rigid pipes under ground subsidence with various crossing scenarios, where the fault plane intersects different positions of the pipeline. Then, the efficiency of TDA mitigation in reducing the risk of pipe failure is evaluated, considering variations in geometry, size and density of TDA zone. It is found that the most detrimental fault-pipe crossing position locates at 3/4L of the pipe barrel, where excessive bending moment can lead to longitudinal cracking. TDA mitigation mainly prevents structural failure of pipelines, while its influence on the kinematics of joints is negligible. The most pronounced loading reduction for pipelines is achieved by employing TDA with a lower degree of compaction, combined with the burial configuration of full-surrounded layout pattern of TDA.

O IMPACTO DE MANIFESTAÇÕES PATOLÓGICAS DO CONCRETO NA DURABILIDADE E SEGURANÇA DAS ESTRUTURAS

This study analyzes the impact of pathological manifestations in reinforced concrete, emphasizing their effects on the durability and safety of structures. Common issues such as cracks, reinforcement corrosion, and spalling were investigated, along with their main causes, including design flaws, improper execution, poor maintenance, and adverse environmental conditions. Through a theoretical approach based on an extensive literature review, this research aimed to understand the origins and consequences of these pathologies and propose solutions to mitigate them. The findings reveal that pathological manifestations not only compromise structural integrity but also increase repair and maintenance costs throughout the service life of buildings. Aggressive environments, such as coastal zones or regions with significant temperature variations, were identified as aggravating factors, accelerating concrete deterioration and raising the risk of structural failures. Preventive measures, such as the use of high-quality materials, regular inspections, and protective coatings, proved essential to minimize the impacts of these pathologies. Furthermore, adopting proper practices during the design and execution stages significantly contributes to extending the service life of structures and ensuring user safety. In conclusion, pathological manifestations in concrete represent a critical challenge for civil engineering, requiring special attention from the initial construction phases to periodic maintenance. This study highlights the importance of combining technical knowledge with the implementation of best practices to preserve the functionality, safety, and aesthetic value of structures. It also underscores the need for future practical studies to further evaluate the effectiveness of various prevention and repair techniques, fostering sustainable development in the construction industry.

Revealing inducible clindamycin resistance in methicillin-resistant S aureus : A vital diagnostic imperative for effective treatment.

The World Health Organization added methicillin-resistant S aureus (MRSA) to the list of "priority pathogens," given its capacity to cause life-threatening infections. Clindamycin is a preferred treatment for non-complicated S aureus-induced skin and soft tissue infections. Its good tissue penetration and oral absorption make it suitable for outpatient therapy. However, the emergence of inducible and constitutive (MLS B ) resistance led to clinical challenges, primarily due to the potential oversight of inducible resistance in routine antimicrobial sensitivity testing. This cross-sectional study was conducted at a tertiary care hospital during 2020-2022. A total of 158 MRSA isolates from various clinical specimens were analyzed. The Kirby-Bauer disk diffusion method using cefoxitin disk and D-test were used to identify MRSA and detect inducible clindamycin resistance (ICR), respectively. Among the 158 MRSA isolates, 34.17% showed constitutive clindamycin resistance (MLS B c), while 22.15% displayed ICR (MLS B i). In addition, 10.13% of isolates demonstrated the MS phenotype, clindamycin, and erythromycin susceptibility, with 53 (33.54%) isolates susceptible to both antibiotics. The relative risk of clindamycin treatment failure was 7.66 times higher if the D-test was not used. To prevent clindamycin treatment failures, the D-test must be implemented to detect ICR in MRSA isolate. Neglecting simple and cost-effective tests may lead to inaccurate susceptibility reporting, jeopardizing treatment success.

Outcomes of bulbar artery sparing during anastomotic urethroplasty for pelvic fracture urethral injury

ObjectiveTo the present long-term outcomes of the vascular-sparing approach during reconstruction of pelvic fracture urethral injuries (PFUI) described by Gomez et al. Material and methodsAnastomotic reconstruction of PFUI is performed without transecting the bulb of the spongiosum, to preserve the antegrade flow of the bulbar arteries. After exposure of the urethra, the bulbar arteries are located using a Doppler stethoscope. The bulb is mobilized dorsally and unilaterally, sacrificing the artery with the weaker Doppler signal to preserve the best contralateral artery. Occasionally, both arteries can be preserved. Removal of all fibrosis and anastomosis is performed as described in the traditional transecting technique. ResultsA total of 60 patients were included, with a mean age of 37 years (IQR 22-48). The median time from trauma to urethral reconstruction was 16 weeks, and the mean stenosis length was 2.5 cm (IQR 2-3). The left bulbar artery was preserved in 27 cases, the right bulbar artery in 8, and both in 24. There were postoperative complications in 14 cases (23%), but only one of them was Clavien ≥ III. With a mean follow-up of 56 months (IQR 12-87), only one patient failed due to stenosis (98% success). ConclusionPreservation of antegrade arterial flow to the corpus spongiosum during PFUI reconstruction is feasible and safe. Although slightly more elaborate, this technique could reduce the risk of ischemic failure of reconstruction.

Early Detection of Students at High Risk of Academic Failure using Artificial Intelligence

Early Detection of Students at High Risk of Academic Failure using Artificial Intelligence

Retreatment predictors after percutaneous balloon gangliolysis for trigeminal neuralgia

Percutaneous balloon ganglyolysis (PBG) for trigeminal neuralgia (TN) is an inexpensive and minimally invasive treatment modality that is effective and safe. While there are reports of its efficacy, there is still a lack of evidence of which patients are at a higher risk of treatment failures and needing retreatment. We performed a retrospective study at a major academic institution from 2012 to 2023, including TN patients who underwent PBG procedures to evaluate predictors of retreatment. Patients without imaging available from the PBG were excluded. Fifty-two patients who underwent 83 procedures in total were included in the analysis. All patients had typical TN and were primarily female (59.6%), with a median age of 61.5 years. Immediately after PBG, 42.3% had pain resolution, and 57.7% had improved but persistent pain. 30.8% underwent retreatment with PBG in a median of 32 months. From multiple factors assessed, TN disease duration ≤ 6 months and trigeminal nerve enhancement on pre-operative MRI were identified as significant retreatment predictors on univariate analysis. However, after performing logistic regression, only TN disease duration ≤ 6 months remained significant OR 3.99 (95% CI 1.59–10.0; p = 0.003). This was further confirmed in a Kaplan-Meier survival analysis, which showed that patients with TN duration ≤ 6 months require retreatment earlier (22 vs. 41 months; p = 0.01). Retreatment after PBG occurs roughly in a third of patients, and TN disease duration of ≤ 6 months is an important predictor in this study. Further studies should be performed to confirm these findings, which may impact treatment considerations in the future.

Nuclear chess on the Korean Peninsula: analysing North Korea’s “second mission” and strategic implications

ABSTRACT This article examines North Korea's evolving nuclear strategy and its implications for regional security. We analyse that North Korea’s first mission, to counter-deter the US nuclear extended deterrence for South Korea by its minimal deterrence strategy, is to be achieved. Then, the article highlights the recent shift in North Korea's nuclear doctrine, as evidenced by Kim Jong-un's statement on the “second mission” beyond deterrence. Focusing on Pyongyang's two nuclear missions, the article first evaluates the current nuclear balance between the US nuclear-extended deterrence to South Korea and North Korea's nuclear forces, shedding light on the risks of deterrence failure. The second mission, framed as reunification through nuclear warfighting, is also examined, including North Korea’s recent strategic manoeuvres, aggressive rhetoric, and large-scale military provocations. We lastly provide potential scenarios of North Korean nuclear attacks and propose policy implications for the US-South Korea Alliance to prevent the escalation of a nuclear conflict.

Occlusion failure analysis and optimization design for steel piston pin hole-pin friction pair

The focus of the present study was on the D25TCIF steel piston, and the underlying causes of pin hole occlusion failure were systematically analyzed. The investigation considered factors such as heat transfer, mechanics, lubrication, material properties, and forging processes. Additionally, an optimization strategy was introduced based on the cause of the failure to reduce the risk of occlusion failure of the pin hole. At the same time, the influence of the structural parameters of the connecting rod small head on the lubrication performance of the pin hole bearing was investigated, providing a theoretical basis for the matching design of the structural parameters of the double friction pair of the piston pin bearing. The findings indicate that the primary cause of pin hole occlusion failure in steel pistons is the concentration of thermo-mechanical coupling stresses and elevated temperatures within the pin hole. This condition results in the rupture of the lubricating oil film in the pin hole bearing, leading to dry friction between the piston pin and the bearing surface. The optimization method designed in the present study enhanced the minimum oil film thickness of the pin hole bearing from 0.354 μm to 0.377 μm, reflecting an increase of 6.50 %. Additionally, the minimum oil film thickness of the small head bearing was improved from 0.599 μm to 0.691 μm, corresponding to a 15.36 % increase compared to the original configuration. Meanwhile, the optimization method predicted a minimum oil film thickness of 0.382 μm for pin hole bearings and 0.693 μm for small-head bearings, with a relative error of less than 5 % from the simulated values. Such findings demonstrate that the optimization method has a good optimization effect and accurate prediction. This approach offers novel insights for the development of future solutions to address the failure of steel pistons in engineering applications.

Benefit of early oseltamivir therapy for adults hospitalized with influenza A: an observational study.

clinical guidelines recommend initiation of antiviral therapy as soon as possible for patients hospitalized with confirmed or suspected influenza. A multicenter US observational sentinel surveillance network prospectively enrolled adults (aged ≥18 years) hospitalized with laboratory-confirmed influenza at 24 hospitals during October 1, 2022-July 21, 2023. A multivariable proportional odds model was used to compare peak pulmonary disease severity (no oxygen support, standard supplemental oxygen, high-flow oxygen/non-invasive ventilation, invasive mechanical ventilation, or death) after the day of hospital admission among patients starting oseltamivir treatment on the day of admission (early) versus those who did not (late or not treated), adjusting for baseline (admission day) severity, age, sex, site, and vaccination status. Multivariable logistic regression models were used to evaluate the odds of intensive care unit (ICU) admission, acute kidney replacement therapy or vasopressor use, and in-hospital death. A total of 840 influenza-positive patients were analyzed, including 415 (49%) who started oseltamivir treatment on the day of admission, and 425 (51%) who did not. Compared with late or not treated patients, those treated early had lower peak pulmonary disease severity (proportional aOR: 0.60, 95% CI: 0.49-0.72), and lower odds of intensive care unit admission (aOR: 0.24, 95% CI: 0.13-0.47), acute kidney replacement therapy or vasopressor use (aOR: 0.40, 95% CI: 0.22-0.67), and in-hospital death (aOR: 0.36, 95% CI: 0.18-0.72). Among adults hospitalized with influenza, treatment with oseltamivir on day of hospital admission was associated reduced risk of disease progression, including pulmonary and extrapulmonary organ failure and death.

Assessment of failure risks during C2 vertebra pedicle screw insertion using three-dimensional computed tomography angiography analysis: the role of high-riding vertebral artery and narrow pedicles.

Cervical fixation is a common treatment for conditions like vertebral fractures, osteosarcoma, osteomyelitis, arthritis, and congenital disorders. The study was designed to assess the occurrence of high-riding vertebral artery (HRVA), narrow C2 pedicles (NC2P) and ponticulus posticus (PP), which pose risks of injuring vertebral artery (VA) during screw placement in cervical fixation procedures. The study examined the prevalence of HRVA, NC2P and PP in 382 pedicle sides of the C2 vertebra using computed tomographic angiography scans. Specific measurements were taken, including the internal height (C2InH), and isthmus height (C2IsH) of C2, as well as NC2P width. HRVA was identified by specific measurements: C2IsH of ≤ 5mm and/or C2InHof ≤ 2mm. NC2P was defined as NC2P width ≤ 4mm. The reliability between observers and within the same observer, along with the consistency across different software, was assessed. At least one HRVA was found in 9.6% of patients and at least one NC2P in 13% of patients. Females demonstrated higher rates of HRVA and NC2Ps on the left side, with right-side figures at 10.5% and 11.7% for HRVA and NC2Ps respectively, and left side figures at 14.1% for both. Males exhibited a reserve pattern, with higher rates on the right side, marked by 10.3% HRVA and 15% NC2Ps, compared to 5.6% and 11.3% on the left. Furthermore, males showed a significantly higher occurrence of NC2Ps over HRVA on both sides. The presence of PP with NC2Ps detected in 44% of cases, and with HRVA in 16% of cases, a difference found to be statistically significant. The digital models incorporating HRVA, NC2P, and PP facilitated a comprehensive analysis of the VA pattern, assessment of the virtual screw trajectory line for VA pedicles, and the designation of specific regions during the procedure, ensuring increased safety planning instrumentation.

Mathematical model of the system performance mode for simultaneous separate well operation

Relevance. The trend of oil production technology development is related to many relevant topics. One of such actual directions is the technology of simultaneous separate well operation, in particular, including two electric centrifugal pumps and double-sided submersible electric motor. The presence of two formations at the bottomhole implies the selection of the optimal layout, technological parameters of pumps pumping oil. Considering production from two independent formations in the well according to the mentioned technology, there is a high need in selection of correct parameters of installations at the design stage. In the absence of correct selection of technological parameters of units at the design stage, further operation of a well with two independent formations can be economically inexpedient, and in some cases unrealizable, which is due to a number of reasons. First, if the necessary underbalance is not provided for each particular formation, counterflow of fluid may occur and one of the pumps will not participate in the production process. Secondly, when operating an arrangement, which capacity significantly exceeds the capacity (fluid flow from the reservoir) of the well, there is a possibility of pumping failure and, as a consequence, there is a risk of potential failure. In this regard, an extremely urgent task at the moment is to ensure correct selection of technological parameters of electric centrifugal pump units used in simultaneous separate operation of wells with two independent formations. Aim. Development of a mathematical model that allows selecting the optimal technological parameters of the arrangement consisting of two electric centrifugal pumps and a double-sided submersible motor, used for simultaneous separate operation of wells with two independent formations. Methods. Numerical simulation methods for analyzing the operation mode of electric centrifugal pumps in conditions of oil production from two independent reservoirs. Results and conclusions. It was obtained that the developed mathematical model of the system operation mode for simultaneous separate operation of wells allows to estimate the potential of each individual selected pump during oil production (in time dynamics) by analyzing the depression on each individual reservoir, as well as modeling the process taking into account the potential backflow of liquid and supply failure.