bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Model for the Analysis of Fluid-Structure Interaction Problems with Cable Coupling
Authors: Tonin Mateus Guimarães , Braun Alexandre Luis
Published: July 2023

The present work proposes the development of numerical tools for solving fluid-structure interaction (FSI) problems where the structure is coupled with cables. For the numerical treatment of fluids in incompressible flow, the Navier-Stokes and continuity equations are discretized using a semi-implicit version of the characteristic-based split (CBS) method in the context of the finite element method (FEM), where linear tetrahedral elements are used. In the presence of moving structures, the flow equations are described through an arbitrary Lagrangian-Eulerian (ALE) formulation and a numerical scheme of mesh movement is adopted. The structure is treated through a three-dimensional rigid body approach and the cable through an elastic model with geometric nonlinearity and spatial discretization by the nodal position finite element method (NPFEM). The system of equations of motion can be temporally discretized using the implicit Newmark and generalized-α methods and a partitioned coupling scheme is used taking into account fluid-structure and cable-structure couplings. The algorithms proposed here are verified using numerical applications.
Human Granzyme K Is a Feature of Innate T Cells in Blood, Tissues, and Tumors, Responding to Cytokines Rather than TCR Stimulation
Authors: Duquette Danielle , Harmon Cathal , Zaborowski Alexandra , Michelet Xavier , O’Farrelly Cliona , Winter Des , Koay Hui-Fern , Lynch Lydia
Published: July 2023

NK cells and CD8 T cells use cytotoxic molecules to kill virally infected and tumor cell targets. While perforin and granzyme B (GzmB) are the most commonly studied lytic molecules, less is known about granzyme K (GzmK). However, this granzyme has been recently associated with improved prognosis in solid tumors. In this study, we show that, in humans, GzmK is predominantly expressed by innate-like lymphocytes, as well as a newly identified population of GzmK+CD8+ non– mucosal-associated invariant T cells with innate-like characteristics. We found that GzmK+ T cells are KLRG1+EOMES+IL-7R+CD62L−Tcf7int, suggesting that they are central memory T and effector memory T cells. Furthermore, GzmK+ cells are absent/low in cord blood, suggesting that GzmK is upregulated with immune experience. Surprisingly, GzmK+ cells respond to cytokine stimuli alone, whereas TCR stimulation downregulates GzmK expression, coinciding with GzmB upregulation. GzmK+ cells have reduced IFN-γ production compared with GzmB+ cells in each T cell lineage. Collectively, this suggests that GzmK+ cells are not naive, and they may be an intermediate memory-like or preterminally differentiated population. GzmK+ cells are enriched in nonlymphoid tissues such as the liver and adipose. In colorectal cancer, GzmK+ cells are enriched in the tumor and can produce IFN-γ, but GzmK+ expression is mutually exclusive with IL-17a production. Thus, in humans, GzmK+ cells are innate memory-like cells that respond to cytokine stimulation alone and may be important effector cells in the tumor.
In-process Defect Monitoring and Correction in Additive Manufacturing of Aluminum Alloys
Authors:   Sentient Science, Jalalahmadi Behrooz ,   John Hopkins University APL, Slotwinski John , Liu Jingfu , Rios Jason , Peitsch Christopher , Goldberg Arnold , Montalbano Timothy
Published: July 2023

Metal additive manufacturing (AM) has become increasingly popular to fabricate complex, light-weight, and highefficiency components for use in the aerospace industry; however, there are inherent limitations in existing AM processes that have delayed widespread implementation for aviation applications. Porosity is just one example of the key characteristics that can impact the mechanical strength of an AM part. This research focuses on a real-time feedback system to detect and correct defects during the powder bed fusion process of aluminum alloys. In this study, AlSi10Mg coupons were built using various AM parameters. The build process was continuously monitored via a high-frequency in-situ infrared camera which had been integrated into a commercial metal powder bed fusion machine. Porosity information (pore location and size) of the as-built AM coupons were characterized using x-ray computed tomography. The monitoring results were post processed and correlated with porosity location, indicating a strong relationship between abnormal sensing signal and pore formation. This demonstrates that the real-time abnormal sensing signal can be a good indicator for identifying pore formation during the AM process. Additionally, Sentient Science Corporation (Sentient) used its advanced modeling technique to simulate the AM build process regarding the melt pool geometry, porosity, and microstructure. Prediction of porosity level at different AM parameters aligned well with the experimental results. Advanced modeling results showed that careful selection of AM settings is required to correct in-process defects. Repair parameters must be tailored to achieve satisfactory correction of individual defects. Combining the in-situ defect monitoring and advanced simulation capabilities enables the creation of a closed-loop feedback control system that provides automatic defect detection and correction action in powder bed additive manufacturing process.
Army Aviation Additive Repair/Manufacture (AR/M) Qualification
Authors:   US Army CCDC AvMC, Cass Wesley
Published: July 2023

The U.S. Army overhauls aircraft weapon system (AH-64, CH-47, UH-60) and associated components. Significant damage, corrosion, and wear are a main cause of component discrepancies. Typical issues with current fusion weld/thermal spray repair is high distortion and a large heat affected zone (HAZ) to an operational aviation component. These repairs often require large and complex fixtures and processes to stabilize the component during the repair process. The additive repair / manufacture (AR/M) has shown to give a very small HAZ and footprint not requiring the use of complex fixtures. This paper outlines the approach taken to develop and qualify AR/M necessary for airworthiness qualification. Two areas that are researched are laser additive manufacturing (LAM) powder fed systems (or directed energy deposition (DED)) and cold spray additive manufacturing. Establishment of mechanical and metallurgical properties of AR/M are presented. Significant return on investment is being shown using these AR/M repair processes.
VPM-Derived State Space Inflow Model for Multi-Rotor Air Vehicle Modeling and Simulation
Authors:   Advanced Rotorcraft Technology Inc., He Chengjian ,   US Army CCDC AvMC, Tischler Mark , Gladfelter Matthew , Chang Chongseok , Juhasz Ondrej
Published: July 2023

To achieve increased speed, range, and payloads of existing rotorcraft, Future Vertical Lift (FVL) considers compound configurations that have multiple rotors, ducted fans, auxiliary wings, etc. The FVL configurations introduce more aerodynamic lifting devices/surfaces that make aerodynamic interaction a dominant phenomenon to address. Recent development of eVTOL air vehicle for urban commuting also involves multiple rotors in order to provide sufficient lift and controls to meet the VTOL requirement within limited landing/takeoff space. There is astrong need for developing a state space inflow modelthat supports flight dynamicsmodelingandsimulation of Future Vertical Lift (FVL) with multi-rotor systems. This paper discusses a systematic approach that is effectively used to derive a finite state induced inflow model from first-principle based viscous Vortex Particle Method (VPM) using the CIFER Rsystem identification tool. The paper presents an inflow model framework that accommodates both the rotor self-induced and mutual interference between an arbitrary number of rotors in one unified formulation. The off-rotor wake interference on aerodynamic surfaces and fuselage is also addressed by the unified formulation. The first-principle based VPM captures the fundamental interactional rotor wake dynamics and provides the accuracy for the inflow model parameters identified from the VPM simulation. The model formulation and model parameter identification method were verified for both single main rotor and co-axial rotor configurations. The verifications were performed by comparing the inflow response of the identified finite state inflow model with first-principle based VPM simulation at various flight conditions in both frequency and time domains. The approach was also validated using measured helicopter frequency response data and excellent agreement between the predicted and the measured response data was obtained.
Enhancement of an Engineering Simulation Model to Improve the Correlation with Flight Test Data in Climb/Descent and Autorotation
Authors:   Sikorsky a Lockheed Martin Co., Xin Hong , Zhang Chi , Driscoll Joseph
Published: July 2023

A high-fidelity engineering simulation model has been developed in FLIGHTLAB for a Sikorsky production helicopter to support future design modifications. The simulation model consists of major subsystems for main rotor, tail rotor, fuselage, empennage, landing gear, flight control system, and propulsion system. As the manufacturer, Sikorsky was able to provide a complete and validated set of model data and a large database of flight test records to ensure the model quality and fidelity. Although the model correlation with test data is satisfactory in most flight conditions including hover, low-speed flight, level flight, and vertical climb, some model-data discrepancies were seen in the forward climb/descent and autorotation test cases. An additional study was conducted at Sikorsky to investigate these discrepancies. Based on the study, a set of model enhancements were developed to improve the model correlation with test data in forward climb/descent and autorotation. These enhancements allow for adjustment of certain semi-empirical corrections to address model limitations at these challenging conditions such as fuselage characteristics and interference at high angles of attack and rotor inflow and interference at low collective settings and near 90-degree wake skew. These enhancements were carefully designed such that the effects were localized so that the model-data correlation was not adversely impacted in other flight conditions. The model-data correlation in forward climb/descent and autorotation were significantly improved by implementing these model enhancements with little to no impact on the other flight conditions resulting in a high-fidelity engineering simulation model validated in the entire flight envelope.
Tandem Rotor Inflow Modeling and its Effect on Vehicle Dynamics
Authors:   Georgia Institute of Technology, Guner Feyyaz ,   Advanced Rotorcraft Technology Inc., He Chengjian ,   The Boeing Company, Miller David , V. J.
Published: July 2023

Inflow modeling is necessary for accurate predictions of performance, aeromechanics, handling qualities analyses and flight simulation of single and/or multi-rotor configurations. There are complete inflow theories, i.e., finite state dynamic wake theory, for single rotor configurations which were shown to correlate well with the test data. However, inflow models of multi-rotor configurations such as CH-47 Chinook helicopter are still heavily dependent on empirical corrections. The physical effects behind adding correction factors are reasoned to wake interference between front and rear rotors. However, effect of the interference on steady-state conditions and mechanism of how it affects the transient response are left unanswered. This paper aims to answer physical reasoning behind the correction factors. For this goal, an industry standard, empirically correlated inflow model, viz., Boeing Helicopter Simulation CH-47 Chinook Inflow Modeling Method (BHSimIMM), is compared with Pressure Potential Superposition Inflow Model (PPSIM). In addition, a high fidelity Viscous Vortex Particle Method (VVPM) is included in the study for gaining further insight into rotor-to-rotor inflow interference. In this study, it is shown that body pitch rate response is greatly affected by uniform inflow interference in hover and forward flight. The body roll rate response characteristic can be improved by having fore-to-aft inflow coupling and uniform to fore-to-aft inflow interference in hover. It is also shown that interference on the front rotor quickly diminishes as speed increases while rear rotor is always under the influence of front rotor.
Flight Training Simulator Fidelity Requirements to Address 'Rotorcraft Loss of Control In-flight'
Authors:   University of Liverpool, White Mark ,   Liverpool John Moores University, Lu Linghai ,   IDT, Advani Sunjoo , Cameron Neil , Padfield Gareth
Published: July 2023

This paper examines the trends in rotorcraft accident statistics, particularly regarding Loss of Control In-flight accidents (LOC-I), with the aim of stimulating interest in new research relevant to this area. Despite recent safety initiatives, LOC-I rotorcraft accidents have been identified as a significant and growing contribution to accident rates. The fixed-wing commercial airline community faced a similar situation starting in the late 1990s and, through a coordinated international effort, developed a new training program to help reduce accident rates. Lessons learned from the fixed-wing work are presented to highlight the need for improved rotorcraft modeling tools to reduce rotorcraft accidents through higher-quality, simulator-based training programs. The findings from previous and ongoing rotorcraft modeling and simulation research are presented, and areas for further research are identified. A proposal is made in the paper for a workshop to bring together the key rotorcraft stakeholders to develop future steps in tackling rotorcraft LOC-I accidents.
Interplay Between Optic Flow, Pilot Workload and Control Response During Aggressive Approach to Hover Maneuvers for Three Vertical Lift Vehicle Models
Authors:   San Jose State University Research Foundation, Bachelder Dr. ,   NASA Ames Research Center, Aponso Bimal , Godfroy-Cooper Dr.
Published: July 2023

This work proposes a novel relationship between pilot workload and optic flow during visual approach-to-land maneuvers. A simulation experiment was conducted at NASA Ames Vertical Motion Simulator (VMS) to evaluate the workload associated with operating two candidate Army Future Vertical Lift (FVL) vehicles: a compound (coaxialrotor and push-prop) vehicle, and a tilt-rotor vehicle. The UH-60 was included in the evaluation as a baseline reference. Sixteen experienced military pilots flew aggressive visual approaches terminating in a hover while providing Bedford workload ratings in real time. No approach or hover guidance was displayed to the pilot. The out-the-window (OTW) environment (front and chin monitors) was digitally recorded and the optical flow of each video frame computed. Prior work identified a mathematical relationship between pilot workload and the combination of display error rate and stick rate during compensatory tracking tasks. The current work extends this relationship to visual landing approaches, where the pilot is hypothesized to track key optical variables that are available from the OTW scene. Hypothesizing that the visual approach is essentially a compensatory task, optical flow rate was combined with stick rate to compute Bedford workload estimates. Actual and estimated Bedford ratings are compared for the three aircraft models. Innovative contributions of this research include: 1) Optical flow from high resolution, high frame rate flight video is computed and analyzed for workload analysis; 2) A modelling technique is developed that produces workload estimates that closely matches actual pilot ratings; 3) A technique based on visual perceptual requirements allows optical flow to be employed in a tractable, effective manner; 4); Using a novel method, Bedford workload ratings were collected in real time without impinging on the flight task, enabling in-situ workload analysis. Lastly, the authors recently proposed a psychophysical approach which characterizes workload response for a given task in concise terms such as sensitivity to stimulus (Weber fraction), just-noticeable difference (JND), and dynamic range. This new methodology is applied to the workload results obtained for the three aircraft models and discussed, demonstrating how a psychophysical treatment to workload brings a different and relevant toolset for quantitatively examining human-machine performance.
Updating US Army Aviation Critical Item Management for 21st Century
Authors:   US Army CCDC AvMC, Rhee Myung , Gray Christopher
Published: July 2023

U.S. Army Aviation has extensively managed critical aircraft components based on the technical requirements and methods outlined in AMCOM Regulation 702-7 Flight Safety Parts/New Source Testing Program Management. This paper provides an overview of the newly revised AMCOM Regulation 702-7, previously published in October 2000. This update was necessary to keep up with the updated requirements of high tier documents, such Public Law 108-136, DA Pam 95-9, and other related regulations. This effort has produced a new AMCOM Regulation 702-7 Critical Safety Items (CSI), Critical Application Items (CAI), and New Source Testing (NST) Program Management, officially released in June 2017. The revised document addresses the complete quality oversight controls for CSIs and includes newly defined oversight and control requirements for CAIs. Furthermore, the new revision has been clarified by incorporating lessons learned while eliminating confusion and ambiguity from the previous document. The appendices have been revised to better describe technical and quality requirements for manufacturers and overhaul sources for CSIs, and also detail the Army programs in place to provide confidence that items inducted into the Army supply system are safe and conforming. In this paper, various technical aspects of CSI, CAI, and NST that have been established for US Army rotary wing aircrafts are presented and discussed in detail.
Maintenance Engineering Support of U.S. Army Aircraft in Southwest-Asia
Authors:   US Army CCDC AvMC, Mason-Leister Andrew , Steiner Bryan , Brychta Ronald , Schroeder Nicholas
Published: July 2023

U.S. involvement in the conflict in Southwest Asia has required prolonged deployment and field-level maintenance of hundreds of mission-critical Army aircraft. Theater settings present unique challenges for the U.S. Army and its aircraft maintainers, crews, and pilots alike. The U.S. Army Combat Capabilities Development Command Aviation and Missile Center deploys Liaison Engineers (LEs) to Southwest Asia in order to maintain airworthiness by delivering hands-on technical and logistical support to theater air crews and maintenance entities. This paper, with input from several previously deployed LEs, offers a look into the duties, responsibilities, and challenges of the LE in Southwest Asia.
Hearing loss and tinnitus associated with COVID-19 vaccines: An analysis from the national pharmacovigilance database in Malaysia
Authors: Lee Sing Chet , Wo Wee Kee , Yeoh Hee Sheong , Choo Sim Mei , Ramli Azuana
Published: July 2023

Objective:

To compare the reporting pattern of hearing loss and tinnitus across different vaccines brands used in Malaysia (BNT162b2, CoronaVac, ChAdOx1, Ad5.CoV2-S and BBIBP-CorV).

Methods:

This retrospective study included all reports of hearing loss and tinnitus occurring after COVID-19 vaccination that were received in the national pharmacovigilance database, QUEST, from February 24, 2021 through July 31, 2022. Reports given causality consistent or indeterminate were included.

Results:

There were 21 cases of hearing loss, with overall reporting rate of 0.29 cases per million doses. The rate was similar across BNT162b2, CoronaVac and ChAdOx1. For tinnitus, 35 cases were reported, with the overall reporting rate of 0.49 cases per million doses, and the highest rate was reported for ChAdOx1. For both events, most cases aged 30 to 49 years. No gender disparity was observed. Both events were mainly reported to have occurred after the primary doses, with a median time-to-onset of two days. There were no statistically significant differences in the reporting patterns for both events across BNT162b2, CoronaVac and ChAdOx1 by age group, gender, race, and dose number.

Conclusions:

Despite the low reporting rates and insufficient evidence to confirm its relationship, hearing loss and tinnitus following vaccinations should not be ignored due to its disabling potential and impact on one's quality of life. Continual reporting is encouraged for better signal characterization in the future.
Rhinofacial conidiobolomycosis in an immunocompetent 30-year-old male: A case report
Authors: Kundu Sourav , Chakraborty Sambudhya
Published: July 2023

Rationale:

Fungal rhinosinusitis is a rare entity in immunocompetent patients and is a diagnostic challenge. Conidiobolomycosis is a rare cause of fungal rhinosinusitis which happens to affect immunocompetent patients.

Patient concerns:

A 30-year-old male patient complained of painless progressive swelling of nose for 5 years and painless progressive swelling of upper lip for 4 years associated with nasal obstruction for 5 years.

Diagnosis:

Rhinofacial conidiobolomycosis.

Interventions:

Systemic anti-fungals and saturated solution of potassium iodide.

Outcomes:

Swelling initially reduced but again increased eventually as he discontinued treatment.

Lessons:

Proper adherence to drugs and need for facial reconstructive surgery may need to be considered in such cases of conidiobolomycosis.
Cryptotanshinone ameliorates cladribine-induced cognitive impairment in rats
Authors: Aran Khadga Raj , Gupta G. D. , Singh Shamsher
Published: July 2023

Objective:

To evaluate the neuroprotective effect of cryptotanshinone against cladribine-induced cognitive impairment in rats.

Methods:

Rats were administered with cladribine (1 mg/kg, p.o.) and cryptotanshinone (10 and 20 mg/kg, i.p.) for four weeks. Behavioral tests such as Morris water maze and elevated plus maze were conducted to check memory impairment caused by cladribine. On day 29, all rats were sacrificed, and the brains were separated for estimation of neuroinflammatory factors, biochemical parameters, neurotransmitters, Aβ(1-42), blood-brain barrier permeability, nuclear factor erythroid 2-related factor 2 (Nrf2), and brain-derived neurotrophic factor (BDNF).

Results:

Treatment with cryptotanshinone dose-dependently enhanced spatial memory, improved the levels of neurotransmitter and antioxidant enzymes, and suppressed proinflammatory cytokine release. Cryptotanshinone also decreased Aβ(1-42) accumulation and increased the levels of Nrf2 and BDNF in the hippocampus. Additionally, the histopathological results showed that cryptotanshinone reduced cladribine-induced neuronal death in the hippocampus.

Conclusions:

Cryptotanshinone exhibits a promising neuroprotective effect against cladribine-induced cognitive impairment in preclinical studies, and may be a potential phytochemical for the treatment and management of cognitive impairment.
Myricetin alleviates ovalbumin-induced allergic rhinitis in mice by regulating Th1/Th2 balance
Authors: Shi Ya-Nan , Su Jin-Zhu , Wang Juan , Geng Jiang-Qiao
Published: July 2023

Objective:

To evaluate the effect of myricetin on ovalbumin (OVA)-induced allergic rhinitis in mice.

Methods:

Mice were sensitized and challenged using OVA (5%, 500 mL) intraperitoneally and intranasally, respectively, on an alternative day for 14 days, followed by administration of myricetin (50, 100, and 200 mg/kg) till day 21. Nasal symptoms, biochemical parameters, protein expressions, and histopathology were observed.

Results:

OVA-induced increased nasal symptoms including rubbing, sneezing, and discharge were significantly reduced by myricetin (100 and 200 mg/kg) (P<0.05). Myricetin also protected against histamine challenge and attenuated elevated serum immunoglobulin E (IgE; total and OVA-specific), total IgG1, and β-hexosaminidase levels, as well as leukotriene C4 and interleukins levels in nasal lavage fluid (P<0.05). Western blot analysis showed that myricetin significantly upregulated the protein expression of T-box expressed in T cells, while downregulating the protein expression of GATA binding protein 3, NF-κB, and 1κВ-α (P<0.05). Additionally, OVA-induced histopathological abberations in the nasal mucosa was markedly ameliorated by myricetin treatment (P<0.05).

Conclusions:

Myricetin exerts anti-allergic effects against OVA-induced allergic rhinitisviaregulating Th1/Th2 balance.
Comparative evaluation of biological, mechanical, and patient-reported outcomes of angulated screw channel abutments versus multi-unit abutment-retained single-unit implant restorations in the anterior esthetic zone: An-in vivo study
Authors: Varshney Niyati , Kusum Chandan Kumar , Trivedi Anshul , Kaushik Mayur , Dubey Prajesh , Bali Yashika
Published: July 2023

Aims:

The study aimed to evaluate biological, mechanical, and patient reported parameters associated with ASC abutments and MU abutments for the fabrication of screw retained implant crowns in the anterior esthetic zone.

Setting and Design:

For the study, 20 patients were selected and implants were placed within the constraints of prosthetic envelope. Later, the screw retained crown was fabricated.

Materials and Methods:

Biological parameters (including implant survival rate, marginal bone levels using cone beam computed tomography, and soft tissue assessment using periodontal indices) were measured at the time of crown placement and 1 year follow up. Mechanical parameter (screw loosening) was calculated using removal torque loss (RTL) values obtained at the time of crown placement and 1 year follow up. Patient reported parameters were evaluated using a questionnaire at 1 year follow up.

Statistical Analysis Used:

All data were tabulated, statistically analyzed, and compared using SPSS version 23 IBM Corporation, Armonk, NY, USA.

Results:

Implant survival was found 100% in both the groups. The marginal bone level reduced considerably in both the groups from baseline to 1 year follow up. The MU abutment group had slightly less marginal bone loss than the ASC abutment group. Additionally, there was no statistically significant difference between the two groups’ periodontal indices at baseline and 1-year follow-up values. At baseline, the RTL value was substantially lower (P<0.003) in the ASC abutment group than in the MU abutment group, however at the 1-year follow-up, there was no statistically significant difference in RTL or screw loosening between the two groups. Patient-reported data showed no statistically significant difference.

Conclusion:

Within the constraints of this study, it was suggested that both ASC and MU abutments provide equally promising results in terms of biological, mechanical, and patient-reported parameters in the anterior esthetic region for single screw-retained crowns.
An in vivo study to assess and compare the angular, linear, and depth deviation as well as the difference in bone density of implants placed using computer-aided design/computer-aided manufacturing fabricated three-dimensional guides versus the implants placed using bone pen kit in maxillary and mandibular ridges
Authors: Aggarwal Shipra , Aggarwal Sumit , Goswami Roma , Mowar Apoorva , Tomar Nitin , Saxena Deepesh
Published: July 2023

Aim:

The aim is to assess and compare angular, linear, and depth deviation and difference in bone density of dental implants placed using computer aided design/computer aided manufacturing (CAD/CAM) fabricated surgical guides versus implants placed using Bone Pen Kit. Till now, no original research exists in the search engines such as Pubmed, Google Scholar, Science Direct, and Research Gate on this kit.

Settings and Design:

In vivo- Randomised control trial.

Materials and Methods:

Twenty clinical cases were selected and split into two distinct groups. Group 1 involved the placement of 10 implants using CAD/CAM fabricated three dimensional guides and Group 2 involved the placement of 10 implants using Bone Pen Kit. Four deviation parameters were evaluated, which included: (a) Angular deviation, (b) Linear deviation at implant platform, (c) Linear deviation at implant apex, and (d) Depth deviation and difference in bone density before and after implant placement was also evaluated.

Statistical Analysis Used:

SPSS software version 23 was utilized for the analysis of the data. The comparison was made using the Whitney test, and Wilcoxon signed rank test.

Results:

When comparing angular deviation, the results indicated a statistically significant difference with a P < 0.05. The values observed for angular and linear deviation in Group 2 were significantly greater than those in Group 1. No statistically significant difference in depth and linear deviation was found at the implant platform among the two groups. Bone density before and after implant placement was significantly higher in Group 1.

Conclusions:

(1) Angular and linear deviation at the apex in Group 2 exhibited higher values in comparison to Group 1, (2) No difference in depth and linear deviation at the implant platform was found among the two groups, and (3) There was no difference in change in bone density among two groups.
Knowledge and Information Resources about Child Abuse among Government and Private Dental Practitioner in Uttar Pradesh, India
Authors: Singh RK , Singh A , Anand S , Kumar D , Ahmad A , Tanwar AS
Published: July 2023

ABSTRACT

Background and Aim:

To evaluate knowledge, attitude, and information sources about child abuse and neglect (CAN) among dentists in Varanasi district of Uttar Pradesh state, India.

Subjects and Methods:

A cross-sectional online survey was carried out of dentist working in government and private hospitals in the Varanasi district, Uttar Pradesh State, India (n = 674). The structured questionnaire was sent through electronic mail that contained the consent form, instructions for filling, and returning the questionnaire. The data obtained were systematically compiled and the Chi-square test was applied to test the association. The significance level of P ≤ 0.05 was applied.

Results:

A maximum number of dental practitioners from the government (81.97%) and private sector (85.98%) were aware of the child protection law. A significant number of government and private dental practitioners were satisfied with their knowledge (p = 0.0092); however, 83.79% suggested that the continuing education programs/courses were important tool to update their knowledge. The girl child was maximum sufferer (p = 0.0056) of CAN. Only 14.08% of practitioners acted on the suspected cases, and a statistical significant relation was observed between the government and private dental practitioners for not taking any action on child abuse and neglect (p = 0.0010).

Conclusions:

Data from this study may provide a useful contribution to the current limited knowledge about the familiarity of dental practitioners with child maltreatment and their skills to recognize and manage CAN cases in their practice. The majority of dental practitioners knew about the child protection law in India, but they were reluctant to report such cases due to the fear of anger from the parents and family of the child. Continuing education programs/courses were the most preferred method for increasing the knowledge regarding CAN. They should report the CAN cases to local legislators and health authorities so to prevent child abuse and neglect from ever occurring.
Can Affinity of Hemoglobin to Oxygen to be a Prognostic Marker in Critically ill COVID-19 patients?
Authors: Alay GH , Tatlisuluoglu D , Turan G
Published: July 2023

ABSTRACT

Background:

This study’s objective is to determine the slope of the hemoglobin oxygen dissociation curve in critically ill patients who have COVID-19 along with blood gas measurements and how mortality might be impacted by this circumstance.

Aim:

It has been reported that the hemoglobin oxygen dissociation curve is not different from healthy patients in COVID-19. However, there are insufficient data on the behavior of the curve in patients who require intensive care.

Patients and Methods:

This retrospective study was conducted between 01.03.2021 and 01.07.2021 with patients who were followed up due to COVID-19 in adult intensive care unit. P50 and lactate value obtained from in vitro calculated blood gas analysis. The survival status of the patients was recorded.

Results:

The mean P50 value at the admission of nonsurvivors was significantly higher than survivors. In correlation analysis, a significant positive correlation was seen between P50, mortality, and lactate level at admission. SpO2, PaO2/FiO2 ratio, and length of stay in intensive care unit were significantly negatively correlated with P50 levels.

Conclusion:

A right shift in the hemoglobin oxygen dissociation curve is associated with mortality. Lactate levels were also associated with a right shift. Prospective experimental studies are needed to provide a better understanding of this process.
Pancreatic Morphology/Contour Variations should be Recognized and Remembered
Authors: Güler İ , Kavak RP
Published: July 2023

ABSTRACT

Background:

Pancreatic contour variations can be detected incidentally on computed tomography (CT). Recognition and remembering of these variations are important in volumetric measurements and surgery as well as in preventing misdiagnosis.

Aim:

This study aims to evaluate the morphology/contour variations in the pancreas head-neck, body-tail, and uncinate process with multi-detector CT (MDCT) examinations (triple phase CT abdomen).

Material and Method:

Around 1662 adult age (>18 years old) patients were evaluated retrospectively, and after exclusion criteria, 945 patients were included in the study. Aplasia and hypoplasia of the uncinate process were determined, and pancreatic contour variances were categorized according to the Ross et al. and Omeri et al. classifications. Pancreatic head–neck variants were categorized into Type I-anterior, Type II-posterior, and Type III-horizontal variations. Pancreatic body–tail variants were sectioned into Type Ia-anterior protrusion, Type Ib-posterior protrusion, and Types IIa-globular, IIb-lobulated, IIc-tapered, and IId-bifid pancreatic tail.

Results:

Of the 945 patients, 481 (50.9%) were female. The mean age was 43.28 ± 10.49 (min. 20–max. 68). In the evaluations made according to the uncinate process morphology variant, hypoplasia was detected in 66 (7%) patients and aplasia in 12 (1.3%) patients. Pancreatic head-neck and body-tail contour variations were observed in 596 (63.1%) patients. The most common head-neck variation was Type II in 233 (24.6%) patients, followed by type III in 96 (10.2%). There were Type Ia in 83 (8.8%) patients and Type Ib in 14 (1.5%) patients. The pancreatic tail configuration was normal in 792 (83.8%) patients; it was Type IIa in 62 (6.6%) patients and IIb in 50 (5.3%) patients. The most common variation was head and tail in 33 (3.5%) patients.

Discussion:

Pancreatic variations detected in CT examinations for distinct reasons are not rare; these variations should be recognized and remembered.
Effect of Piezoincision on the Rate of Mandibular Molar Mesialization: A Randomised Clinical Trial
Authors: Ogrenim M , Cesur MG , Demetoglu U , Yucel ZP , Avcı B
Published: July 2023

ABSTRACT

Background and Aim:

The aim of this clinic study was to investigate the effect of piezoincision on the rate of mandibular molar mesialization using clinical, radiological, and biochemical methods.

Materials and Methods:

Twenty-one patients requiring mandibular first molar extraction and second molar mesialization were included in the study which was designed as split-mouth study. Piezoincision was performed on the buccal surface of alveolar bone following regional alignment to the randomly selected side. 150 g of force was applied to the second molar teeth using mini-screw-supported anchorage after the piezoincision. Cone beam computed tomography (CBCT), gingival crevicular fluid (GCF) and digital model records of the patients were obtained. Two- and three-dimensional measurements were performed and compared on the CBCT images in a study which lasted 24 weeks.

Results:

According to the model analysis, the canine-second molar distance was consistently reduced and a greater decrease was measured on the experimental group (p < 0.05). Second molar mesial rotations increased in both groups (p < 0.001). Two-dimensional measurements on CBCT images showed increased mesial and buccal tipping of second molars in experimental group (p < 0.001). There was a significant increase in mesialization measurements of experimental group (p < 0.001). Three-dimensional measurements on the CBCT images showed a decrease of root length in both groups (p < 0.001), and a greater decrease was found in the experimental group (p < 0.001). When intra-group changes in GCF results were examined, it was observed that there was no significant change in osteoprotegerin (OPG) values over time in experimental group (p = 0.148).

Conclusion:

The piezoincision technique provided acceleration of mandibular molar mesialization and did not cause further damage to the buccal alveolar bone. Piezoincision can be used as a safe method in the mandibular molar region.
Effects of Oral Steroids Combined with Postauricular Steroid Injection on Patients with Sudden Sensorineural Hearing Loss with Delaying Intervention: A Retrospective Analysis
Authors: Liu ZB , Zhu WY , Fei B , Lv LY
Published: July 2023

ABSTRACT

Background:

In the otology clinic, we often receive some sudden sensorineural hearing loss (SSNHL) patients accompanied by annoying tinnitus, who usually visited over three weeks after the onset. Nevertheless, due to the high treatment cost and relatively low cure rate, there are still great disputes about hospitalization or not for these patients.

Aim:

This study aimed to perform a retrospective analysis for analyzing the efficacy of treatment with oral steroids combined with postauricular steroid injection in patients with delaying effective treatment.

Material/Methods:

A total of 157 eligible SSNHL patients with delaying effective treatment over three weeks were enrolled in this study. According to different treatment methods of oral steroids with or without postauricular steroid injection, these patients were divided into three groups: PO (prednisone oral) group, PSI (prednisone oral and postauricular steroid injection) group, and PII (prednisone oral and postauricular lidocaine injection) group. The changes in level of hearing, mean subjective tinnitus loudness, and side effects were analyzed in the three groups.

Results:

Hearing improvement and tinnitus remission were all observed in three groups after treatment. Compared with PO and PII groups, those patients in PSI groups had more improvement in level of hearing and mean subjective tinnitus. The level of tinnitus loudness was statistically significantly correlated with the level of PTA both before treatment and after treatment.

Conclusion:

Oral steroids combined with postauricular steroid injection should be employed for treatment of SSNHL patients with delaying effective treatment over three weeks.
Predictors of Mortality among Drug-Resistant Tuberculosis Patients in Kaduna State, Nigeria
Authors: Oyefabi AM , Tobin West CI , Ameh S , Jiya EN , Sadiq A , Dauda H , Onoh M
Published: July 2023

ABSTRACT

Background:

Specific death due to DR-TB has significantly contributed to tuberculosis (TB) mortality and overall global deaths.

Aim:

This study examines the predictors of mortality among DR-TB patients in Kaduna State, Nigeria.

Subject and Method:

This was a retrospective longitudinal study of DR-TB mortality carried out among 370 DR-TB patients from the 23 LGAs in Kaduna State. It involves a retrospective review of the MDR-TB records of the patients over a period of 10 years (2012–2021). Demographic and clinical data of all DR-TB patients enrolled in Kaduna State, Nigeria, between April 1, 2012, and March 31, 2021, were used. Survival analysis was performed with SPSS version 25, using Kaplan–Meier and Cox proportional hazard regression modeling, at 5% significance level.

Results:

The majority of the patients, 255 (68.9%), were below the age of 40 years, while 53 (14.3%) of the patients died within the study period. Most deaths 26 (49.1%) were associated with HIV co-infection and the disease severity. Results for the Cox proportional model show that there was a significantly lower risk of death when a patient had MDR-TB compared to pre-XDR-TB (adjusted hazard ratio, AHR = 0.34, 95% CI = 0.16–0.72, P = 0.04). Both models show that age, sex, residence, or year of treatment had no significant association with survival or death.

Conclusion:

HIV co-infection and DRTB with progression to more resistant and difficult-to-treat strains contributed to higher deaths. There is a need for concerted efforts from all DR-TB stakeholders to control the disease.
Incidence of Missed Middle Mesial Canal in Endodontically treated Mandibular Molar Teeth: A Cone-Beam Computed Tomography Study
Authors: Tartuk GA , Kaya S
Published: July 2023

ABSTRACT

Background:

In endodontic treatment, the aim is to completely determine, shape, and fill all root canals in a three-dimensional way. Missed canals lead to treatment failure. In mandibular molars, there may be an extra canal called the middle mesial canal between the mesiobuccal and mesiolingual canals.

Aim:

The aim of this study was to evaluate the prevalence of missed middle mesial canals in root canal-treated mandibular molar teeth.

Materials and Methods:

In this study, cone-beam computed tomography (CBCT) images of 1054 patients were analyzed. We identified 121 endodontically treated mandibular molars and evaluated the prevalence of missed canals.

Results:

Although 33.05% of the root canal-treated teeth did not have a middle mesial canal, this canal was detected in the other 66.94%; 97.53% of teeth with a middle mesial canal could not be detected by clinicians.

Conclusion:

Clinicians performing endodontic treatment of mandibular molar teeth should not ignore the presence of the middle mesial canal. Thus, it is very important for clinicians to have sufficient information about the localization, morphology, and variations of the middle mesial canal.
Diagnostic Contribution of Magnetic Resonance Imaging and Computerized Tomography in Patients with Unidentified Vertigo and Normal Neurologic Examination in Emergency Medicine
Authors: Buyurgan CS , Eray O , Yigit O , Yaprak N , Unal A , Senol U
Published: July 2023

ABSTRACT

Background:

Vertigo and dizziness are common symptoms in patients presenting to emergency medicine (ED) clinics. Vertigo may be caused by peripheral or central origin. Routine imaging is not indicated; however, neuroimaging is increasing, and published studies have revealed a small number of positive findings on imaging modalities.

Aims:

The aim of this study was to investigate whether neurological imaging was necessary in patients classified as “unidentified vertigo,” who were admitted to the emergency department with vertiginous complaints and not revealing typical peripheral vertigo findings and any neurological deficits.

Materials and Methods:

All patients with “dizzy symptoms” were included in the study. For patients who met the definition of “unidentified vertigo,” experimental neurological imaging studies were done. Head computerized tomography (CT), magnetic resonance imaging (MRI) with gradient-echo sequences (GRE), and diffusion weighted images (DWI) were used for imaging. Patients who underwent neuroimaging in the ED were followed up for 6 months in Neurology and ENT clinics.

Results:

A total of 351 patients were included in the study. Experimental imaging was performed on 100 patients. CT detected a significant pathology associated with the vertigo complaint in only one patient. MRI results were similar to the CT results. MRI-GRE sequences showed some additional pathologies in 14 patients and 4 of them were thought to be related to vertiginous symptoms. None of the patients classified as “non-central causes of vertigo” in the neuroimaging group developed TIA or CVD during 6 months of follow-up.

Conclusion:

Head CT can be adequate to exclude life-threatening central pathology in “undifferentiated vertigo patients” and the addition of MRI did not add any diagnostic accuracy in ED management. Using the physical examination findings effectively to make a specific diagnosis may reduce misdiagnosis and improve resource utilization.
Percutaneous Kidney Biopsy and the Histopathologic Patterns of Kidney Diseases in Children: An Observational Descriptive Study at a South-East Nigerian Tertiary Hospital
Authors: Mbanefo NR , Igbokwe OO , Iloh ON , Chikani UN , Bisi-Onyemaechi AI , Muoneke VU , Okafor HU , Uwaezuoke SN , Odetunde OI
Published: July 2023

ABSTRACT

Background:

Kidney biopsy remains the best standard for kidney tissue analysis. Although percutaneous kidney biopsy is an invasive procedure, it is an indispensable part of interventional nephrology for accurate diagnosis, selection of appropriate therapy protocol, and prognostication of kidney diseases in children. With improvement in expertise among pediatric nephrologists, data on procedure outcomes are now being documented.

Aim:

We aimed to describe the outcomes in a 5-year practice of kidney biopsy at the pediatric nephrology unit in a southeast Nigerian tertiary hospital.

Patients and Methods:

An observational descriptive study conducted on the kidney biopsy performed in our facility from 2017 to 2022. The focus was on the patients’ clinical profile, indications for biopsy, the adopted procedure, and the histopathologic findings.

Results:

A total of 69 patients had kidney biopsy, 40 (58.0%) were males, while 29 (42.0%) were females. Sixty-four (92.7%) patients had the procedure at the age of >10 years, while five (7.2%) at the age of <7 years. The patients’ prebiopsy mean systolic and diastolic blood pressures were 111.20 ± 16.93 and 74.64 ± 12.69 mmHg, respectively. Their estimated glomerular filtration rate (eGFR) was 119.27 ± 52.78 ml/min/1.73 m2. The most frequent indication was steroid resistance (39/69, 56.5%). Focal segmental glomerulosclerosis was the commonest histopathologic finding (38/69, 55.0%).

Conclusion:

Outcomes of percutaneous kidney biopsy at a Nigerian tertiary hospital are adjudged successful. The histopathologic patterns highlight FSGS as the major cause of steroid resistance in childhood nephrotic syndrome in this clime.
Management of Accidental Fracture and Embolization of Intravenous Cannula in Peripheral Veins using a Novel J- Flap Technique: A Case Series
Authors: Isiguzo C , Opara C , Uzoho A , Opara K
Published: July 2023

ABSTRACT

The use of intravenous cannulas is a common procedure in healthcare. It’s a common way of accessing the intravenous route for several purposes in patient care. Procedure is fraught with a significant risk of fracture and embolization of cannula that merits immediate intervention. There is paucity of well-defined techniques in literature for retrieval of such fractured cannulas from peripheral veins. A case series highlighting the use of a novel J-flap surgical technique in the management of fractured intravenous cannula in six (6) adult patients by the authors over a 24-month period. The intervention reduces or eliminates the risk of central embolization with its attendant severe consequences and invasive intervention. The learning curve of the technique seems gentle and does not need sophisticated surgical instrumentation.