bluuebunny/crossref_metadata_2025 huggingface dataset:
An enhanced mechanism for detection of Domain Name System‐based distributed reflection denial of service attacks depending on modified metaheuristic algorithms and adaptive thresholding techniques
Authors: Manickam Selvakumar , Rahef Nuiaa Riyadh , Hakem Alsaeedi Ali , Alyasseri Zaid Abdi Alkareem , Mohammed Mazin Abed , Jaber Mustafa Musa
Published: July 2022

The rapid growth of the number of devices connected to the Internet and the increasing demand for electronic services have led to a huge growth in the number of cyberattacks targeting cyberspace and the development of their methodology. Therefore, there must be mechanisms, laws, and rules regulating the work of these applications and protecting them from electronic attacks. The Domain Name System (DNS) has several vulnerabilities that can be exploited by cyber attackers to launch their attacks, and the most important one of these vulnerabilities is that the response size is always greater than the size of the request. According to reports published by numerous security companies, distributed reflection denial of service (DRDoS) attacks against DNS are regarded as one of the most hazardous and rapidly spreading threats in recent years. An enhanced mechanism that is able to detect DNS‐based DRDoS attacks that exploit the DNS responses to launch their attacks is proposed. The proposed mechanism was designed based on modified metaheuristic optimization algorithms and an adaptive threshold. This mechanism consists of two models and four stages. The first model is called ‘Proactive Feature Selection,’ and the second model is called ‘Evolving Dynamic Fuzzy Clustering.’ The four stages of the proposed mechanism are: the preprocessing stage, feature selection stage, detection stage, and enhancement stage. The new mechanism has been implemented on the CICDDoS2019 standard dataset and achieves a detection accuracy of 95.44% with a false‐positive rate of 0.22%. The results show that the new mechanism is better than others depending on the detection accuracy and false positives.
Spray in cross–flow: comparison of experimental and numerical approach
Authors: Cejpek Ondrej , Maly Milan , Bělka Miloslav , Slama Jaroslav , Hajek Ondrej , Prinz Frantisek , Jedelský Jan
Published: July 2022

The spray behaviour and droplet trajectories in realistic conditions are of crucial importance in many industrial, agricultural and chemical applications. Droplet characteristics and spray trajectory in chemical applications (e. g. flue gas scrubbing, CO2 capture in spray column) determine the amount of mass involved in the gas scrubbing process, mass trapped by the flow or attached to the walls. Knowledge of the droplet behaviour can improve a nozzle design and scaling, increase the process efficiency, minimize the process liquid and blow away the fraction. In this study, experiments with pressure swirl nozzle in cross–flow of air were performed at one nozzle injection pressure (0.5 MPa) and several cross–flow velocities (8, 16, 32 m/s). The results on droplet trajectories are compared with numerical results obtained by ANSYS Fluent. Two Lagrange approaches for spray modelling were used. Injection of droplet groups and Linearized Instability Sheet Atomization (LISA) model incorporated within ANSYS Fluent were used to represent the spray. The CFD results of spray penetration and droplet trajectories are compared with experimental data. A simple analytical model is able to well predict trajectories of large droplets, but fails to predict trajectories of small droplets. The LISA model yields a better accuracy for spray in cross-flow prediction.
Pool boiling heat transfer on minichannels with porous structure
Authors: Dadas Norbert , Pastuszko Robert , Kaniowski Robert
Published: July 2022

The work focused on the investigations and comparison of pool boiling heat transfer on the specimens with in 5 mm deep and 1 mm wide parallel mini-channels to the specimens with additional porous material (copper foam or mesh) between the fins. The experiments were carried out with boiling FC-72 at atmospheric pressure. Many works show that enhanced surfaces with open minichannels improve heat transfer performance substantially. The use of additional porous material led to the highest heat transfer coefficients in the range of 100 to 230 kW/m2. The coefficients obtained were 15% higher and the superheat was 15% lower compared to the plain smooth minichannel without porous material.
Pollutant dispersion in a group of courtyard buildings
Authors: Ferrari Simone
Published: July 2022

As stated by the World Health Organization (WHO), the air pollution in the urban environment is the silent cause for around seven million death worldwide. This is due to the indoor and outdoor exposure to various pollutants emitted in the built environment: as the global trend is an increase of the population living in towns, this issue is predicted to become even worser. As a matter of fact, the built environment can cause the trapping of pollutants instead of their dispersion. In this work, the dispersion of a plume of a pollutant (carbon monoxide, CO), emitted from a chimneystack above the roof of courtyard in a group of courtyards, is investigated. This is achieved employing the ENVI-met software, able to model, among the others, the turbulence and pollutant dispersion in the built environment. Results show, among the others, how the pollutant emitted from an upstream building can harm also the downstream buildings.
Ventilation in a group of courtyard buildings
Authors: Ferrari Simone
Published: July 2022

In the contemporary urban planning, the outdoor comfort is more and more relevant. As a matter of fact, in some Nations the microclimate design, and so, among the others, a quantification of the outdoor comfort is already compulsory, while in many others it is recommended. Various methods to quantify the outdoor comfort can be adopted (e.g., among the others, the PMV-Predicted Mean Vote, or the PET-Physiological Equivalent Temperature), but in every formulation the quantification of the wind velocity, otherwise referred to as ventilation, close to the buildings under study is needed. In this paper, the ventilation inside and outside a group of courtyard buildings is studied via numerical simulations with ENVI-met. ENVI-met is a three-dimensional microclimate model able to simulate the ventilation in an urban environment and the interaction of air flows with surfaces of different materials, with plants and with other typical elements of the built environment in a given climate. Results highlight the relevance of the mutual influence of buildings and of their dimensions in modelling the ventilation inside and outside a courtyard.
Experimental investigation of homogeneous nucleation of water in various gases using an expansion chamber
Authors: Lukianova Tetiana , Lukianov Mykola , Hrubý Jan
Published: July 2022

Nucleation is an integral part of phase transitions and plays an important role in technology. The control of nucleation in devices such as turbines, rocket and jet engines, wind tunnels, and combustion processes is key to achieving efficient, ecologically sound operation. Our paper presents information about a modernized experimental setup used for homogeneous water nucleation research. The main goal of the study is an analysis of the influence of carrier gas on homogeneous nucleation. The experimental setup based on an expansion chamber has been used for research of homogeneous nucleation over several decades and has undergone various technical improvements. In the Institute of Thermomechanics, the setup was been completely disassembled and cleaned. Pressure transducers, laser, and the data acquisition system have been replaced with modern parts. After that, the chamber was assembled, and thoroughly tested and calibrated. Our investigations were carried with argon and nitrogen as carrier gases in a range of nucleation temperatures 220 – 260 K, pressure range 80-150 kPa, at several concentrations of water vapour. The results thus obtained are consistent with literature data. The findings suggest that this experimental approach is useful for homogeneous water nucleation research.
CFD analysis of the ultrasonic gas meter channel
Authors: Novosád Jan , Pulec Jaroslav , Dančová Petra , Vít Tomáš
Published: July 2022

This paper describes a process of numerical testing and optimization of the ultrasonic gas meter channel. A conventional ultrasonic flowmeter requires a large installation space due to the quality and stability of the velocity profile. Previously, the shape of the inner gas meter channel was optimized to reach a suitable flow field for ultrasonic measurement. The goal of this work is to find an optimal design of reduced size gas meter to achieve a stable velocity profile with minimum disturbances regardless of the entry conditions in the smallest possible space. Flow characteristics for volume flow rate in the range (1 to 250) m3/h were tested and the parameters of the gas meter were adjusted. Obtained results show good match with the requirements. Future work should aim to the measurement of transit time and the stability of measured values on the optimized design. Finally, it will enable to create the analogy between numerically obtained velocity fields and real transit time measurement.
Advances in simulations of heat exchange in fluid flows by high-order methods
Authors: Pech Jan
Published: July 2022

The article presents high-order simulations of heat transfer in fluid flow. Heat induced changes in material properties (density, viscosity and heat conductivity) substantially influence flow structures. The change of fluid density implies naturally the thermal expansion what results in non-homogeneous divergence of velocity and the model of evolutionary Navier-Stokes-Fourier equations is not strictly incompressible in this case. Proposed algorithm treats the model as a fully coupled system of equations. Applied method of operator splitting is promissing to become a more general concept for numerical modelling of active quantities advected by incompressible fluids. This work follows the 2D results presented during EFM 2019 and extends to 3D together with advances of the code reimplementation to current version of the Nektar++ library (open-source framework for spectral/hp finite elements). Results for various settings for both the forced/mixed and natural convection are shown.
On the stall flutter occurrence in a blade cascade set to turbine and compressor geometry
Authors: Procházka Pavel , Šnábl Pavel , Chindada Sony , Bublík Ondřej , Uruba Václav
Published: July 2022

A blade cascade allowing free pitch movement of five blades was developed in Institute of Thermomechanics. This model is introduced to study the phenomenon of stall flutter existing in rotary bladed wheels of steam turbines and other devices. This article describes how to induce the stall flutter for prescribed boundary conditions (as inlet velocity, various angles of attack, etc.) and gives survey about flow field differences around the cascade set to both the turbine and the compressor geometry. This experimental research utilized time-resolved Particle Image Velocimetry (PIV) to measure and to evaluate statistical quantities of the wake behind the NACA0010 profiles of the cascade. Also dynamical analysis was performed in the form of Fast-Fourier transform and also phase-locked measurement was applied. Gained knowledge will be utilized to design advanced model of the cascade allowing stall flutter examination without the use of ball bearings.
Preliminary measurements of the thermal field in a rectangular channel by the Planar Laser-Induced Fluorescence method
Authors: Pulec Jaroslav , Mony Pavel , Vinš Václav , Dančová Petra
Published: July 2022

This paper describes the preliminary measurements of the temperature field in water channel by the Planar Laser-Induced Fluorescence (pLIF) method in the one-colour mode using commercial LaVision system. The aim of the work is to find suitable parameters of the experiment (concentration of fluorescent dye, laser power, arrangement of the experiment, etc.) for measuring the temperature field in a closed glass channel of rectangular cross-section with a heated bottom-wall and to verify an applicability of this method in general. The intention is to carry out measurements in the transverse plane of the duct such that the specific thermos-convective structures of the Rayleigh-Bénard-Poiseuille convection, i.e. mixed convection, are detected. For simplicity, the initial measurements were performed in the natural convection regime, i.e. the water in the channel was not driven by the circulation pump. In this case, a larger temperature gradient was created near the wall compared to the force convection case when a cold liquid flows continuously into the experimental area. The presented work serves as a methodological guide for future measurements and provides valuable experience for the design of a new channel for investigation of the thermal flow instabilities.
Aerodynamic and dynamic loading in a blade cascade designed for flutter research
Authors: Šidlof Petr , Šimurda David , Lepicovsky Jan , Štěpán Martin
Published: July 2022

Flow-induced vibration of turbine and compressor blades, so called blade flutter, represents a serious problem for designers and operators of large turbomachines. The research of mechanisms leading to this dangerous aeroelastic instability, which can occur especially in modern long and slender blades, is hindered by lack of experimental data. A new experimental setup for controlled flutter testing has been designed in cooperation of the Institute of Thermomechanics of the Czech Academy of Sciences and Faculty of Mechatronics of the Technical University of Liberec. The test section consists of five planar blades placed in a transonic wind tunnel, with high-frequency torsional oscillation of the middle blade driven by an electric motor. The contribution presents the results of first measurements, namely the static pressure distribution for various inlet Mach numbers, aerodynamic moments and deformation of the middle blade due to inertial loads during high-frequency oscillation.
Pressure losses reduction in a steam turbine compact valve
Authors: Slama Vaclav , Simurda David , Tajc Ladislav , Rudas Bartolomej , Hala Jindrich , Luxa Martin , Radnic Tomas
Published: July 2022

Valves are integral parts of modern steam turbines. They provide flexible operations and fast load changes which have become more often due to the increasing share of renewable energy. Along with this, the low pressure loss is required for guaranteed operation conditions. This paper is concerned with investigation of pressure losses in the compact valve, which is used as a valve for the intermediate-pressure turbine part, and its geometry modification to lower overall pressure losses. The investigation is based on results of numerical simulations which were carried out in the Doosan Skoda Power Company using a package of ANSYS software tools. Source of increased pressure losses in the compact valve is identified and a way of its reduction is proposed based on the comparison of the current results with data from a typical control valve model. Data analysis is provided in the paper.
Contribution on the kinematics of the polishing process on a polishing machine with horizontal overarm
Authors: Veselý Lukáš , Matoušek Ondřej , Vít Tomáš , Müller Miloš
Published: July 2022

Understanding and controlling of the polishing process on conventional NC controlled machines is an important step to optimize production, reduce machine time and increase quality of production. The paper deals with the basic analysis of the problem and its comparison with the experiment performed during the real process on the machine and with the numerical MBS simulation of the process.
Effect of Microvascular Decompression of the Vagus Root Entry/Exit Zone on Blood Pressure in Patients with Hemifacial Spasm Associated with Essential Hypertension: A Retrospective Clinical Analysis
Authors: Wei Xuefeng , Wang Jiao , Kong Xuerui , Gao Caibin , Wang Feng
Published: July 2022

Background This study aimed to evaluate blood pressure alterations after microvascular decompression (MVD) surgery in patients with hemifacial spasm (HFS) with coexisting hypertension (HTN).

Methods A total of 56 patients with HFS with concurrent HTN who underwent MVD surgery in our center between 2015 and 2019 were retrospectively analyzed. Patients were divided into control and experimental groups: patients who received MVD treatment for only the facial nerve and those who received MVD for the affected facial nerve, ipsilateral vagus nerve, and adjacent ventrolateral medulla, respectively. Preoperative (3 days) and postoperative (7 days and 6 months) blood pressure measurements were analyzed.

Results No statistically significant differences were observed in gender, age, HFS course, HTN course, HTN grade, and preoperative blood pressure between the two groups. No significant difference was observed between pre- and postoperative blood pressure in the control group. In the experimental group, systolic blood pressure significantly differed between 3 preoperative days and 7 postoperative days (p < 0.05), as did diastolic blood pressure (p < 0.05). Measurement at 6 postoperative months also showed significant differences for both systolic blood pressure and diastolic blood pressure compared with that at 3 preoperative days (p < 0.05). HTN grade according to the World Health Organization classification criteria significantly differed between preoperative and postoperative measurements (p < 0.05).

Conclusion Vascular decompression of the ipsilateral vagus nerve roots may improve blood pressure management in patients with HFS with coexisting HTN who undergo MVD. Laterality of involvement (left vs. right) did not significantly differ.
Gamma Knife Radiosurgery for Large Vestibular Schwannoma More Than 10 cm3: A Single-Center Indian Study
Authors: Yeole Ujwal , Prabhuraj A. R. , Arivazhagan Arimappamagan , Narasingarao K. V. L. , Vazhayil Vikas , Bhat Dhananjaya , Srinivas Dwarakanath , Govindswamy Bhanumathi , Sampath Somanna
Published: July 2022

Introduction Gamma Knife radiosurgery (GKRS) is an effective treatment for benign vestibular schwannomas (VSs). The established cutoffs have recently been challenged, as recent literature expanded the horizon of GKRS to larger tumors. Even though microsurgery remains the primary option for large VS, GKRS can provide reasonable tumor control and is more likely to avoid cranial neuropathies associated with open surgery.

Methods We analyzed patients with VS with volume exceeding 10 cm3 who underwent GKRS at our center from January 2006 to December 2016. Clinicoradiological and radiosurgical data were collected from medical records for statistical analysis. Follow-up was performed every 6 months with a clinical assessment along with magnetic resonance imaging (MRI) of the brain and audiometric evaluation in patients with serviceable hearing.

Results The study included 34 patients (18 males and 16 females) with an average age of 45.5 years. The mean tumor volume was 10.9 cm3 (standard deviation [SD], ± 0.83), with a median tumor dose of 12 Gy (interquartile range, 11.5–12) and a mean follow-up of 34.7 months (SD, ± 23.8). Tumor response was graded as regression in 50%, stable in 44.1%, and increase or GKRS failure in 2 cases (5.8%). Treatment failure was noted in five cases (14.7%), requiring microsurgical excision and a ventriculoperitoneal shunt post-GKRS. The tumor control rate for the cohort is 85.3%, with a facial preservation rate of 96% (24/25) and hearing loss in all (5/5), while three patients developed new-onset hypoesthesia. We noted that gait ataxia and involvement of cranial nerve V or VII at initial presentation were associated with GKRS failure in univariate analysis.

Conclusion Microsurgery should remain the first-choice treatment option for large VSs. GKRS is a viable alternative with good tumor control and improved or stabilized cranial neuropathies with a low complication rate.
The P300 Auditory Evoked Potential in Cochlear Implant Users: A Scoping Review
Authors: Amaral Maria Stella Arantes do , Zamberlan-Amorin Nelma Ellen , Mendes Karina Dal Sasso , Bernal Sarah Carolina , Massuda Eduardo Tanaka , Hyppolito Miguel Angelo , Reis Ana Cláudia Mirândola Barbosa
Published: July 2022

Introduction The P300 auditory evoked potential is a long-latency cortical potential evoked with auditory stimulation, which provides information on neural mechanisms underlying the central auditory processing.

Objectives To identify and gather scientific evidence regarding the P300 in adult cochlear implant (CI) users.

Data Synthesis A total of 87 articles, 20 of which were selected for this study, were identified and exported to the Rayyan search software. Those 20 articles did not propose a homogeneous methodology, which made comparison more difficult. Most articles (60%) in this review compare CI users with typical hearing people, showing prolonged P300 latency in CI users. Among the studies, 35% show that CI users present a smaller P300 amplitude. Another variable is the influence of the kind of stimulus used to elicit P300, which was prolonged in 30% of the studies that used pure tone stimuli, 10% of the studies that used pure tone and speech stimuli, and 60% of the studies that used speech stimuli.

Conclusion This review has contributed with evidence that shows the importance of applying a controlled P300 protocol to diagnose and monitor CI users. Regardless of the stimuli used to elicit P300, we noticed a pattern in the increase in latency and decrease in amplitude in CI users. The user's experience with the CI speech processor over time and the speech test results seem to be related to the P300 latency and amplitude measurements.
Migraine with Brainstem Aura Associated with SCN2A Mutation: A Case Report
Authors: Membrilla Javier A. , Sastre-Real María , Tirado Pilar , Díaz-de-Terán Javier
Published: July 2022

Background Migraine with brainstem aura (MBA) is a rare subtype of migraine with aura that associates headache with paroxysmal episodes of ataxia, dysarthria, and diplopia among other symptoms attributed to brainstem involvement. The manifestation of this disease in the absence of typical aura symptoms (i.e., fully reversible visual, sensory and/or speech/language symptoms) is even more infrequent.

Case Report In this article, we reported a case of a 16-year-old male patient with MBA associated with a sodium voltage-gated channel alpha subunit 2 (SCN2A) de novo mutation. The patient did not have typical aura symptoms. Ataxia was the most prominent clinical feature, leading to initial diagnosis of episodic ataxia. Patient responded partially to treatment with onabotulinum toxin A.

Conclusion MBA needs to be taken into consideration in the differential diagnosis of recurrent ataxia, even in the absence of typical aura symptoms. Finding a de novo SCN2A mutation in our patient helps in further understanding of MBA genetics.
CALA: Cumulative Volume of Calcified Lesions of the Aorta in Cardiac Surgery
Authors: Ioannou Stelios , Braun Christian , Hartrumpf Martin , Kühnel Ralf-Uwe , Vafa Ali , Schröter Filip , Albes Johannes
Published: July 2022

One of the major key questions raised in this retrospective study was to identify any correlation of atherosclerotic plaque volume of the ascending aorta and aortic arch with adverse events such as postoperative stroke, critical illness polyneuropathy and myopathy, as well as delirium and all-cause in-hospital mortality. In a second phase of this study, we investigated the relationship between atherosclerotic plaque volume and adverse events regarding the construction of proximal anastomosis on coronary artery bypass grafting procedures using different clamping techniques such as construction of anastomosis on cross-clamping or cross-clamping plus consecutive partial clamping of the aorta. The key findings of our research were that the size of calcium lesions of the ascending aorta and aortic arch correlates with early mortality, critical illness polyneuropathy/myopathy, and delirium but not with stroke. On the other hand, there were no significant differences between isolated cross-clamping versus cross-clamping plus consecutive partial clamping of the aorta regarding the primary adverse events by means of mean plaque volume.
Technologies and Mental Health in University Students: An Unhealthy Combination
Authors: Silva Mariana Pires Ferreira Novaes da , Cardoso Gabriela Miloch da Silva , Priolo Filho Sidnei Rinaldo , Weber Silke Anna Theresa , Corrêa Camila de Castro
Published: July 2022

Introduction The exposure of medical students to a full-time schedule that includes classes, extracurricular activities, patients' lives responsibility, and great competition between classmates can interfere in emotional issues and in the sleep time.

Objective The aim of the present study was to evaluate the sleep quality, and the incidence of anxiety and depression in medical school undergraduates as well as the relationship of these parameters with the intense use of technologies.

Methods Fifty-five medical school undergraduates in their second year participated in the present study, answering questionnaires to evaluate sleep quality (Pittsburgh sleep quality index - PSQI), night-time use of technology (sleep time-related information and communication technology - STRICT), and signs of anxiety or depression (hospital anxiety and depression scale - HADS).

Results The results showed 31 students (56.4%) with poor sleep quality (PSQI > 5). Based on the STRICT questionnaire, 36 (65.4%) of the participants referred to making use of technology at night-time; and 34 (61.8%) students had compatible anxiety score, while 14 (25.4%) had a compatible score for depression on the HADS questionnaire. There has been a correlation between poor sleep quality, the abuse of technologies before sleep time, and the presence of anxiety or depression.

Conclusion The abuse of technology before sleep time reduced the sleep quality in the studied population, besides increasing the symptoms of anxiety and depression.
The Effect of Prosthesis Type on Intraoperative Soft-Tissue Balance and Clinical Outcomes in Modified Kinematically Aligned Cruciate-Retaining Total Knee Arthroplasty
Authors: Matsumoto Tomoyuki , Nakano Naoki , Ishida Kazunari , Takashima Yoshinori , Maeda Toshihisa , Kuroda Yuichi , Hayashi Shinya , Matsushita Tekehiko , Niikura Takahiro , Muratsu Hirotsugu , Kuroda Ryosuke
Published: July 2022

Introduction Kinematically aligned total knee arthroplasty (KA-TKA) has gained interest for achieving more favorable clinical outcomes than mechanically aligned TKA. One of the advantages of KA-TKA is reported to be an easy acquisition of intraoperative soft-tissue balance without excessive medial release for varus osteoarthritis. However, we hypothesized that the prosthesis type affects intraoperative soft-tissue balance even in the KA-TKA. The present study aimed to compare intraoperative soft-tissue balance and clinical outcomes of KA-TKAs using single-radius (SR) or multiradius (MR) prostheses.

Materials and Methods Consecutive 70 cruciate-retaining modified KA-TKAs (31 SR and 39 MR) were performed in patients with varus-type osteoarthritis using a navigation system. Intraoperative soft-tissue balance including joint component gap and varus/valgus balance was measured with femoral component placement and patellofemoral joint reduction throughout the range of motion using offset-type tensor and compared between the two groups. Two years postoperatively, the range of motion and 2011 Knee Society Scores were compared between the two groups.

Results and Conclusion Joint component gaps showed no significant differences between the two groups from 0 to 30 degrees of flexion. However, during 60 to 120 degrees of flexion, joint component gaps of SR group showed significantly larger values than those of MR group (p < 0.05). There were no significant differences in varus/valgus balance throughout the range of motion between the two groups. The postoperative clinical outcomes showed no significant differences between the two groups.

Interpretation Despite no difference in clinical outcomes, joint component gap showed different patterns due to the prosthesis type in modified KA-TKAs.
The Effect of Vitamin D Levels in Multisystem Inflammatory Syndrome in Children
Authors: Kan Ahmet , Türe Mehmet , Akın Alper , Yılmaz Kamil , Sürücü Mehmet , Ünal Edip , Şen Velat , Üzel Veysiye Hülya
Published: July 2022

Objective Multiple factors being overweight, asthmatic, or being of Asian or black ethnic origins have been reported vis-à-vis the “multisystem inflammatory syndrome in children” (MIS-C). There is an association between these conditions and vitamin D deficiency, which explains why MIS-C is more common in these patients. In the present study, we attempted to retrospective evaluate the 25-hydroxy vitamin D levels of patients with MIS-C, its association with acute phase reactants, its treatment, and clinical status.

Methods Patients aged between 1.5 months to 18 years with MIS-C were included in the study. All of the laboratory parameters, treatment, and response to the treatment were evaluated retrospectively. Two groups were formed. Patients had 25‐hydroxycholecalciferol D vitamin < 20 ng/mL in group 1 and ≥ 20 ng/mL in group 2.

Results A total of 52 patients were included in the study. There was no statistical difference between groups in terms of acceptance of the intensive care unit treatment (p = 0.29) and response to the first-line treatment (p = 0.56). A lower median lymphocyte count (p = 0.01) and a higher median C-reactive protein (p = 0.04) and procalcitonin (p = 0.01) with N-terminal pro-B-type natriuretic peptide (p = 0.025) values were found in group 1.

Conclusion Vitamin D deficiency was associated with an increased inflammatory response in children with MIS-C. More studies are required to determine the potential impact of vitamin D deficiency on the clinical outcome of MIS-C.
Distal Femoral Tracker Pin Placement Prevents Delayed Pin Tract-Induced Fracture in Robotic-Assisted Total Knee Arthroplasty: Results of Minimum 1-Year Follow-Up
Authors: Baek Ji-Hoon , Lee Su Chan , Kim Jin-Hong , Ahn Hye Sun , Nam Chang Hyun
Published: July 2022

The purpose of this study was to determine the outcomes of the placement of a pin tracker in the distal femur in robotic-assisted total knee arthroplasty (TKA) over a minimum follow-up period of 1 year. A consecutive series of 81 TKAs were performed in 59 patients using a robotic-assisted system (Mako) at our hospital. The mean follow-up period was 1.1 years (range, 1–1.2 years). No periprosthetic fracture at a pin tracker site was reported at a minimum of 1 year of follow-up. No patients reported minor or major complications associated with the distal femoral pins. In addition, unicortical pin-site drilling marks in all patients disappeared on one-postoperative-year follow-up radiographs. Our technique, which used unicortical pin placement in the distal femur in robotic-assisted TKA, demonstrated that it was a safe and reliable method at a minimum follow-up period of 1 year. The level of evidence is IV.
Analysis of Health-Related Quality of Life and Clinical Evaluations in Patients with the Triad of Combined Knee Injuries
Authors: Ochiai Satoshi , Hagino Tetsuo , Senga Shinya , Yamashita Takashi , Ando Takashi , Taniguchi Naofumi , Haro Hirotaka
Published: July 2022

Combined knee injuries of the anterior cruciate ligament (ACL), medial collateral ligament (MCL), and medial meniscus were called “the unhappy triad” in the past. With recent advances in diagnostic technology, combined ACL, MCL, and lateral meniscus injuries are now known to be the predominant triad. We examined and verified the treatment outcomes of the triad of combined knee injuries from both patient-based subjective evaluation and objective assessments. We studied 49 knees (49 patients) with combined injuries of the ACL, MCL, and lateral meniscus. These cases were divided into those who underwent simultaneous ACL and MCL reconstruction (group A, 18 cases) and those who underwent ACL reconstruction only because MCL injury could be treated conservatively (group B, 31 cases). Clinical evaluation was conducted preoperative and 24 months or longer after surgery. The methods included patient-reported outcomes using Short Form-36, and conventional assessments using Lysholm's score, visual analogue scale (VAS), and quantitative measurement of knee instability using Telos SE. Compared with presurgical scores, the postsurgical Short Form-36 scores showed improvements in all eight subscales, all reaching the national standard values. Significant improvements were observed in the five subscales in group A and seven subscales in group B. Furthermore, significant improvements in Lysholm's score, VAS pain score, and quantitative knee instability were achieved in both groups. This study demonstrated successful clinical outcomes in patients with a triad of knee injuries who were treated with lateral meniscus repair or partial meniscectomy and either combined MCL/ACL reconstruction or ACL reconstruction alone.
Clinical Response to Adjunctive Pegylated Interferon Alpha-2a Treatment in Disseminated Mycobacterial Infection in Children with Complete IFNGR1 Deficiency: A Case Report
Authors: Atakul Gizem , Atay Özge , Asrak Hatice Karaoğlu , Erbaş İrem Ceren , Asilsoy Suna , Belet Nurşen , Boyacıoğlu Özge Kangallı , Köse Seda Şirin , Al Serdar , Uzuner Nevin , Karaman Özkan
Published: July 2022

Objective Interferon gamma receptor 1 (IFNGR1) deficiency is a primary immunodeficiency that causes systemic infections with weakly virulent nontuberculous mycobacteria, which are very difficult to control with combined antimycobacterial agents.

Methods Disseminated mycobacterial infection that could not be controlled with combined antimycobacterial treatments in a 13-year-old patient with a novel mutation in the IFNGR1 gene. Despite receiving intravenous antibiotic therapy, fever continued, bone involvement gradually increased, and proteinuria and microscopic hematuria occurred. Peg-IFNα-2a was administered as an adjuvant therapy that resulted in good clinical response with no side effects. Fever improved and no new bone lesions occurred with edema of existing lesions regressing after 2 weeks of peg-IFNα-2a therapy.

Conclusion Aggressive treatment with antimycobacterial antibiotics and hematopoietic stem cell transplantation remains the single accepted method for the management of patients with complete IFNGR1 deficiency. Peg-IFNα-2a treatment may be an adjunct treatment in this disorder.
Torsion of a Wandering Spleen Involving the Pancreatic Tail and Splenic Flexure and Isolated Left-Sided Portal Hypertension due to Chronic Splenic Vein Thrombosis
Authors: Kachare Manohar , Jaisinghani Pooja
Published: July 2022

Wandering spleen is a rare entity, wherein the spleen is attached only by an elongated vascular pedicle, predisposing it to complications like hilar torsion, infarction, rupture, etc. Pancreatic volvulus is another very rare anomaly, with isolated case reports described in association with wandering spleen. The presentation varies from asymptomatic lump (stimulating a mass) to acute abdomen (due to torsion). We present a case of 26-year-old female patient who complained of pain in abdomen, and was radiologically diagnosed and surgically confirmed to have a torsion of wandering spleen with involvement of pancreatic tail and splenic flexure. Few cases with associated finding of gastric volvulus and sigmoid volvulus have been described previously. Involvement of descending colon in a 9-year-old child has been reported. However, to the authors' knowledge, this is the first case report describing the combination of wandering spleen with splenic flexure and pancreatic tail involvement in an adult.
Spectrum of Clinical and Radiological Presentation of Midgut Malrotation in Children and Adolescents: Case Series
Authors: Saurya Saurya , Sherwani Poonam , Sharma Garima , Saxena Sudhir
Published: July 2022

Midgut malrotation is usually present in the early neonatal period with intestinal obstruction and bilious vomiting. However, sometimes it may present later in childhood and adolescence with atypical features and then may remain undiagnosed for long, adversely affecting the growth and development of the child. Here we describe three cases of intestinal malrotation with various atypical presentation and imaging findings.
Acute Colonic Variceal Bleeding in a Cirrhotic Patient Treated by Modified Balloon-occluded Retrograde Transvenous Obliteration: A Case Report
Authors: Yasin Ahmad L. F. , Kassamali Rahil Hussein , Khader Mohammad , Almokdad Omran , Barah Ali Raza , Omar Ahmad
Published: July 2022

Colonic varices are an uncommon type of ectopic varices that can occur due to underlying liver cirrhosis and portal hypertension. They form a very rare cause of lower gastrointestinal bleeding that can result in massive hemorrhage. We present a 38-year-old woman with a background of ulcerative colitis complicated by primary sclerosing cholangitis-induced liver cirrhosis presenting with fresh rectal bleeding. The colonoscopy failed to identify the source of bleeding. Then, computed tomography scan showed multiple dilated tortuous venous collaterals around the descending colon that extended into the colonic submucosa and drained via the left ovarian vein representing colonic varices. She underwent balloon-occluded retrograde transvenous obliteration (BRTO), which successfully embolized these varices with no significant complications. Despite there being no established management guidelines for colonic variceal bleeding, BRTO is a minimally invasive procedure that can be considered as good option for the treatment of these varices, especially when other alternatives are not applicable.
Combined Use of Negative Oral Contrast and Ranitidine for Magnetic Resonance Cholangiopancreatography: A Randomized Controlled Trial
Authors: Natarajan Aravintho , Phansalkar Dilip S. , Kurian George , R. Mithun Raj , T. Preeth Pany , Jayabalan Jayaranjeetham
Published: July 2022

Objective Magnetic resonance cholangiopancreatography (MRCP) is a noninvasive imaging modality to study pancreaticobiliary tree. The primary aim of this study was to compare the image quality of MRCP obtained with the use of ferric ammonium chloride (negative oral contrast) with that of combined use of ferric ammonium chloride and ranitidine (administered orally). Secondary aim was to determine the interobserver agreement between the assessing radiologists.

Materials and Methods The study was a single-center randomized-controlled trial. The patients were randomized into two groups. One group received ranitidine orally and ferric ammonium chloride (Dexorange) and the other group received only the ferric ammonium chloride. The images were qualitatively analyzed independently by the two blinded radiologists. Two scoring systems were used for grading the diagnostic quality of the images: the gastrointestinal tract signal intensity score (range: 1–4) and the structure visibility score (range: 0–3). The mean score of contrast effect and image effect of the two groups were compared by using Mann–Whitney U test. A p-value < 0.05 was considered statistically significant. Interobserver agreement was studied using Cohen kappa coefficient.

Results A total of 93 patients were eligible for the study. Forty-one patients were randomly assigned to the group that received only negative oral contrast and 52 group that received both ranitidine and negative oral contrast. The mean score of the images obtained with using both ranitidine and negative oral contrast was significantly higher when compared with the other group (3.02 vs. 2.7) (p-value = 0.018). However, there was no significant difference in mean structure visualization score of various parts of the pancreaticobiliary system. The interobserver agreement between the two readers in our study was acceptable.

Conclusion Combined use of hematinic syrup and ranitidine increases the image quality by improving the suppression of gastrointestinal fluid signal as compared with the use of only hematinic syrup as negative oral contrast.
Intraosseous Dermoid Presenting as an Expansile Lytic Lesion
Authors: O'Shea Grace E. , Watson Victoria L. , Acakpo-Satchivi Leslie
Published: July 2022

Cranial dermoids have the tendency to occur in the midline, especially near fontanelles and sutures early in the life of a patient. Here we present an unusual case of an intraosseous dermoid that presented initially as a lytic lesion, off of the midline and not associated with cranial sutures or fontanelles. The diameter of the lesion grew to approx 15 mm over time, thus the decision was made to take the child to surgery for removal of dermoid with the use of neuronavigation and cranioplasty. A dermoid cyst was confirmed on histopathologic analysis.
A Decade of Pediatric Intensive Care Outreach and the Deteriorating Child—The Relationship between Dose and Outcomes in a Tertiary Children's Hospital
Authors: Kirby Lynette , Chagan Jayshan , Adams Catherine , Duns Natalie , Haddad Michael , Pearson Sarah , Tegg Oliver , Goh Chong Tien
Published: July 2022

The aim of this study is to evaluate the amalgamation and maturation of a Pediatric Intensive Care Outreach Service (PICOS) with a rapid response system (RRS) and associated outcomes over a 10-year period. It is a single-center retrospective study analyzing patient outcomes within the context of significant organizational changes introducing a track and trigger RRS called Between the Flags (BTF) and evolution of this system to electronic observation charting and alerts (eBTF) in a tertiary metropolitan children's hospital. Children on inpatient wards who required urgent activation of the RRS and admission to the pediatric intensive care unit (PICU) between 2009 and 2018 were included. Three cohorts were identified according to the system changes—pre-BTF (2009–2011), BTF (2012–2017), and eBTF (2017–2018). The PICOS dose (number of activations per 1000 hospital admissions) increased with the introduction of BTF and the RRS and this trend continued following eBTF. The number of PICU admissions via the PICOS did not vary across the decade. When comparing the pre-BTF to the BTF group, PICU mortality decreased (p < 0.05), Pediatric Index of Mortality 2 Risk of Death scores improved, and hospital length of stay decreased (p < 0.05) in the BTF group. Introduction of a track and trigger RRS and electronic charting augmenting an existing PICOS is associated with increasing dose and workload, with no significant impact on PICU admission rates or length of stay. PICOS patient mortality has notably decreased with the introduction of an RRS; however, this impact was not sustained with the addition of electronic charting and alerts in the patient medical record.
Venous Thromboembolism in Surgically Treated Esophageal Cancer Patients: A Provincial Population-Based Study
Authors: Akhtar-Danesh Gileh-Gol , Akhtar-Danesh Noori , Shargall Yaron
Published: July 2022

Objective Venous thromboembolism (VTE) is a major cause of morbidity and mortality in surgical patients. Surgery for esophageal cancer carries a high risk of VTE. This study identifies the risk factors and associated mortality of thrombotic complications among patients undergoing esophageal cancer surgery.

Methods All patients in the province of Ontario undergoing esophageal cancer surgery from 2007 to 2017 were identified. Logistic regression identified VTE risk factors at 90 days and 1 year postoperatively. A flexible parametric survival analysis compared mortality and survival up to 5 years after surgery for patients with and without a postoperative VTE.

Results Overall 9,876 patients with esophageal cancer were identified; 2,536 (25.7%) underwent surgery. VTE incidence at 90 days and 1 year postoperatively were 4.1 and 6.3%, respectively. Patient factors including age, sex, performance status, and comorbidities were not associated with VTE risk. VTE risk peaked at 1 month after surgery, with a subsequent decline, plateauing after 6 months. Adenocarcinoma was strongly associated with VTE risk compared with squamous cell carcinoma (SCC) (odds ratio [OR] 2.53, 95% confidence interval [CI] 1.38–4.63, p = 0.003). VTE risk decreased with adjuvant chemotherapy (OR = 0.58, 95% CI 0.36–0.94, p = 0.028). Postoperative VTE was associated with decreased survival at 1 and 5 years (hazard ratio = 1.57, 95% CI 1.23–2.00, p < 0.001).

Conclusion Esophageal cancer patients with postoperative VTE have worse long-term survival compared with those without thrombotic complications. Adenocarcinoma carries a higher VTE risk compared with SCC. Strategies to reduce VTE risk should be considered to reduce the negative impacts on survival conferred by thrombotic events.
Rivaroxaban Plus Aspirin for Extended Thromboprophylaxis in Acutely Ill Medical Patients: Insights from the MARINER Trial
Authors: Spyropoulos Alex C. , Goldin Mark , Ageno Walter , Albers Gregory W. , Elliott C. Gregory , Hiatt William R. , Halperin Jonathan L. , Maynard Gregory , Steg P. Gabriel , Weitz Jeffrey I. , Spiro Theodore E. , Lu Wentao , Marsigliano Jessica , Raskob Gary E. , Barnathan Elliot S.
Published: July 2022

Background The MARINER trial evaluated whether postdischarge thromboprophylaxis with rivaroxaban could reduce the primary outcome of symptomatic venous thromboembolism (VTE) or VTE-related death in acutely ill medical patients at risk for VTE. Although aspirin use was not randomized, approximately half of the enrolled patients were receiving aspirin at baseline. We hypothesized that thromboprophylaxis with once-daily rivaroxaban (10 mg or, if creatinine clearance was 30–49 mL/min, 7.5 mg) plus aspirin (R/A) would be superior to placebo without aspirin (no thromboprophylaxis [no TP]).

Methods We compared the primary and major secondary outcomes in the intention-to-treat population in four subgroups defined at baseline: (1) R/A (N = 3,159); (2) rivaroxaban alone (N = 2,848); (3) aspirin alone (N = 3,046); and (4) no TP (N = 2,966). Major bleeding (MB) and nonmajor clinically relevant (NMCR) bleeding were assessed in the safety population on treatment plus 2 days.

Results Patients on R/A had reduced symptomatic VTE and VTE-related death compared with no TP (0.76 vs 1.28%, p = 0.042), and experienced less symptomatic VTE and all-cause mortality (p = 0.005) and all-cause mortality alone (p = 0.01) compared with no TP. Event incidences for rivaroxaban alone (0.91%) or aspirin alone (0.92%) were similar. MB was low in all groups but lowest in the no TP group. NMCR bleeding was increased with R/A compared with no TP (p = 0.009).

Limitations Aspirin use was not randomized.

Conclusion Extended postdischarge thromboprophylaxis with R/A was associated with less symptomatic VTE and VTE-related death compared with no TP in previously hospitalized medical patients at risk for VTE. NMCR bleeding was increased with R/A compared with no TP. These post hoc findings need confirmation in a prospective trial.