Reduction In Head Research Articles

Influences of sedimentation on overflow properties of sharp-crested weir

A sharp-crested weir is the simplest type of weir and is mainly used for discharge measurement in open channels. The surface profile of an ogee weir also is designed based on the lower nappe profile of the free jet passing over a sharp-crested weir. In the current study, influences of sedimentation on the discharge coefficient and lower nappe profile of a sharp-crested weir were experimentally investigated. The results indicated that for a specific discharge value, an increase in upstream sedimentation depth results in the reduction in the water level of the approach flow to the sharp-crested weir, and, consequently, a reduction in the weir water head. As the discharge coefficient is inversely influenced by the weir water head, increases in the sedimentation depth resulted in raising the discharge coefficient of the sharp-crested weir up to 42%. Furthermore, the results indicated that with increases in upstream sedimentation depth, the lower nappe profile of the free jet passing over the sharp-crested weir tends toward that of a vertical drop. Under upstream sedimentation, the discharge coefficient of the sharp-crested weir is mainly influenced by the weir's effective height (difference between weir height and sedimentation depth) and it is minimally influenced by sediment grain sizes. Using the experimental results supported by dimensional analysis, the discharge coefficient of the sharp-crested weir was accurately derived as an increasing function of the ratio of weir water head to weir effective height.

Head, face and neck injury patterns for electric scooter accidents identified on computed tomography scanning: Does legislative change enforcing safer riding practices have an impact on morbidity for significant head, face and neck trauma?

The purpose of this study is to review whether legislative change enforcing safer riding conditions for Electric Scooters (E-Scooter), regardless of other factors, had an impact on reducing significant head, facial and neck trauma. Additionally, to identify the radiological injury patterns for head, face and neck injuries identified on CT imaging for a patient's initial presentation to the emergency department (ED) resulting from an E-Scooter accident. A retrospective single-centre observational study at a metropolitan tertiary ED of patients presenting after an E-Scooter accident comparing 6 months before and after legislative change. Four hundred and forty-three patients presented following an E-Scooter accident: 191 patients 6 months before and 252 patients 6 months after legislative change. One hundred and sixty-two patients pre- and 217 patients post-legislative change had negative CT studies. Twenty-nine patients pre- and 35 patients post-legislative change had CT studies demonstrating significant head, face or neck trauma. The most common type of intracranial bleeding was subarachnoid haemorrhage followed by subdural haemorrhage with a significant proportion (41%) presenting with multi-factorial intracranial bleeding. There was no specific injury pattern involving the cranial vault or cervical spine. Of the patients presenting with a significant injury, facial bones were the most common injury site (84% (n = 54)). The most common site of facial fractures was the nasal bones followed by dental trauma and maxillary fractures. This single-centre, retrospective observational study has shown no reduction in serious head, neck and facial injuries. Large-scale, multicentre studies will need to be undertaken to understand the true impact of legislative change.

Evolution of large-scale flow structures in an axial-flow pump during performance breakdown

This paper presents a very large eddy simulation analysis of the unsteady flow in the pre-stall to stall transition process of an axial-flow pump, with the aim to elucidate the spatiotemporal evolution of large-scale flow structures during the performance breakdown of the pump. The transient flow is investigated utilizing a time-dependent flow rate computation scheme. The results demonstrate that, as the flow rate is dynamically reduced, the reduction in pump head is found lags behind the reduction in flow rate by approximately 15 impeller revolutions. The leading edge separation on the blade suction side (SS) evolves into a leading edge separation vortex (LSV) in conjunction with the dynamic reduction in flow rate. The attached flow on the SS in the vicinity of the hub and blade trailing edge squeezes the mainstream outwards, resulting in the formation of a cross passage vortex (CPV) on the tip side of the passage. The combined effect of the LSV, CPV, and tip-clearance flow induces a penetrating upstream flow in the tip region of the impeller, which gives rise to a swirling backflow within the inlet pipe. At stall, the CPV is stably attached to the SS and extends upstream of the leading edge of the neighboring blade. Furthermore, a trailing edge backflow is observed near the junction of the blade trailing edge and the hub, and it collides with the inflow near the hub, resulting in the formation of a hub-attached vortex.

The Influence of Lobe Top Clearance on the Performance of High-Speed Centrifugal Pumps

High-speed centrifugal pumps are widely used in several industries due to their high efficiency and small footprint. In actual applications, there are issues such as low operational efficiency and a small high-efficiency flow interval; particularly, the leakage occurring in the impeller channel gap presents a significant barrier to the pump’s performance and stability. This study takes the fully open impeller miniature high-speed centrifugal pump as the object and uses a numerical simulation calculation method. The objective of this research endeavor is to analyze the effects of different flow conditions on a high-speed centrifugal pump’s external characteristics, flow field characteristics, and energy loss. The findings indicate that lobe top clearance exerts a substantial impact on the efficiency of high-speed centrifugal pumps. Increasing the lobe top clearance will result in a reduction in pump head and efficiency, particularly under high flow conditions. The lobe top clearance has a significant impact on the complexity of the flow in the impeller, particularly the flow close to the suction surface of the impeller, according to an analysis of the flow field characteristics. The energy loss analysis further confirms the importance of reducing lobe top clearance for improving pump performance and reducing energy loss. These results provide valuable guidance for optimizing centrifugal pump designs with lobe top clearance.

Immunological Signatures for Early Detection of Human Head and Neck Squamous Cell Carcinoma through RNA Transcriptome Analysis of Blood Platelets.

Although there has been a reduction in head and neck squamous cell carcinoma occurrence, it continues to be a serious global health concern. The lack of precise early diagnostic biomarkers and postponed diagnosis in the later stages are notable constraints that contribute to poor survival rates and emphasize the need for innovative diagnostic methods. In this study, we employed machine learning alongside weighted gene co-expression network analysis (WGCNA) and network biology to investigate the gene expression patterns of blood platelets, identifying transcriptomic markers for HNSCC diagnosis. Our comprehensive examination of publicly available gene expression datasets revealed nine genes with significantly elevated expression in samples from individuals diagnosed with HNSCC. These potential diagnostic markers were further assessed using TCGA and GTEx datasets, demonstrating high accuracy in distinguishing between HNSCC and non-cancerous samples. The findings indicate that these gene signatures could revolutionize early HNSCC identification. Additionally, the study highlights the significance of tumor-educated platelets (TEPs), which carry RNA signatures indicative of tumor-derived material, offering a non-invasive source for early-detection biomarkers. Despite using platelet and tumor samples from different individuals, our results suggest that TEPs reflect the transcriptomic and epigenetic landscape of tumors. Future research should aim to directly correlate tumor and platelet samples from the same patients to further elucidate this relationship. This study underscores the potential of these biomarkers in transforming early diagnosis and personalized treatment strategies for HNSCC, advocating for further research to validate their predictive and therapeutic potential.

3593: Target volume standardisation and reduction in head and neck tumours: Chances and risks

3593: Target volume standardisation and reduction in head and neck tumours: Chances and risks

Metabolomics Analysis of Variation in Grain Quality of High-Quality Japonica Rice

In recent years, the semi-glutinous japonica rice variety has been extensively utilized in Jiangsu Province to greatly increase rice quality. Nevertheless, the increasing occurrence of seed variation presented a major threat to rice quality. Enhancing the quality of rice grains has emerged as a critical factor in guaranteeing consumer acceptance. Throughout this investigation, five lines (VJ1, VJ2, VJ3, VJ4, and VJ5) selected from the Nanjing9108 population in Liyang were used as research materials, and original cultivars of Nanjing9108 (CKJ1) provided by the original breeder were utilized as control materials to compare rice quality and differential metabolites. VJ4 and VJ3 demonstrated a significant reduction in milled rice rate and head milled rice rate when contrasted to CKJ1. Compared with CKJ1, the amylose content of the five strains was significantly increased. Only VJ3 amplified the 106 bp target band, and its 2-AP content was 0 ng/g. Most metabolites are mainly enriched in cutin, suberine, wax biosynthesis, histidine, and tryptophan metabolism. The primary metabolites throughout the metabolic pathway involve lipids and lipid-like molecules (mono palmitin, alpha-eleostearic, and palmitic acid) and amino acid metabolites (L-glutamate, L-tryptophan, and L-serine). The identification of these key metabolites helps in the discovery of prospective biomarkers for screening seed variation throughout seed production.

Effectiveness of FIFA 11+ Injury Prevention Programs in Reducing Head and Neck Injuries, Including Concussion, Among Soccer Players: A Systematic Review and Meta-Analysis.

To evaluate the effectiveness of FIFA 11+ and 11+ Kids injury prevention programs in reducing the incidence of head and neck injuries among soccer players. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, 2 investigators independently conducted searches in databases (Cochrane Library, PubMed, Web of Science, and PEDro) using keywords like "FIFA 11+," "football," "soccer," and "injury prevention." Only randomized controlled trials assessing FIFA 11+ programs in soccer players were included. Data analysis used the random effects model with RevMan Meta-Analysis software (version 5). Among 397 studies, 4 met inclusion criteria. Pooled results from 7109 players and 532,341 exposure hours indicated a significant 40% reduction in head and neck injuries per 1000hours of exposure in the intervention group compared to the control group (injury risk ratio 0.60, 95% CI, 0.41-0.88). Implementing FIFA 11+ injury prevention programs significantly reduces the risk of head and neck injuries in soccer players, offering a compelling alternative to traditional warm-ups. This study contributes valuable evidence for optimizing injury prevention strategies in soccer training regimens.

The Effect of Corrective Exercises on Ground Reaction Forces in Male Students With Upper Crossed Syndrome During Throwing.

Poor posture has a negative impact on physical capability and is associated with changes in biomechanics and motor control. The purpose of this study was to assess the effect of corrective exercises on ground reaction forces (GRFs) in male student handball players with upper crossed syndrome (UCS) during throwing. Thirty male handball students with UCS participated in this single-blind randomized controlled trial (IRCT20200622047888N2; IR.HUMS.REC.1402.135). Fifteen received an 8-week corrective exercise intervention (exercise-intervention group [EG]), consisting of exercise targeting muscles involved in the UCS, and 15 served as the control group (CG). During handball throwing, GRF was measured by force plate. The forward head and rounded shoulder angles were measured with a photogrammetric method. All measurements were repeated 8weeks later. Significant interactions for virtually all parameters indicated that changes over 8weeks differed between the CG and EG.A reduction in GRFs and a delayed occurrence of peak GRFs were observed in the EG,but not in the CG (P < .05). This was accompanied by a significant reduction in forward head (P < .03; effect size: 0.87; 95% confidence interval, -2.34 to 0.13), rounded shoulder (P < .05; effect size: 0.68; 95% confidence interval, 0.32 to 1.22) and thoracic kyphosis (P < .02; effect size: 0.64; 95% confidence interval, 0.54 to 1.25) angles in the EG (P < .05) with no significant change over 8weeks in the CG. Corrective exercises targeting muscles directly involved in UCS induces functional and postural improvements in male student handball players with UCS.

Quantifying groundwater recharge in the Venetian high plain between the Brenta and Piave Rivers through integrated surface–subsurface hydrological modeling

Study regionVenetian high plain between the Brenta and Piave Rivers, Northeast Italy. Study focusGroundwater recharge is the process by which aquifers, i.e., the groundwater reservoirs, are replenished. In many regions, recharge fluxes are currently declining due to more frequent hydroclimatic extreme events and unsustainable land use management. In this study, CATHY (CATchment Hydrology), an integrated surface–subsurface hydrological model (ISSHM), is used to estimate current and future recharge fluxes in a study area that represents an important source of drinking water supply for the Treviso province (Veneto Region, Northeast Italy). In particular, we aim to evaluate the impacts on recharge of a scenario with changed irrigation management, planned in compliance with European directive indications, to decrease water withdrawals from the Piave River and preserve its ecological flow. The model was first calibrated through a combination of FePEST and the Shuffled Complex Evolution algorithm, whereby both the bottom of the unconfined aquifer and the hydraulic conductivity field were tuned. After a validation step, the resulting model was used to simulate a scenario in which the flood irrigation method, currently the most widespread in the study area, is fully replaced by sprinkler irrigation. New hydrological insights for the regionOur results show that, in response to a 50 % decrease in water withdrawn from the Piave River, the total recharge decreases by about 10 %, with a local reduction in groundwater head, mainly limited in wells located in the area directly affected by the conversion of the irrigation technique. The model suggests that most of the recharge fluxes occur in irrigated areas where the hydraulic conductivity is higher. Overall, this work resulted in the development of an ISSHM capable to reproduce groundwater dynamics and its drivers at high resolution and large scale. Although it can still be improved, the model represents a useful tool to investigate possible responses of the considered hydrosystem to future land use and climate change.

Comparison of selected photon shield and organ-based tube current modulation for radiation dose reduction in head computed tomography: A phantom study.

The aim of this study is to investigate the radiation dose and image quality of head CT using SPS and OBTCM techniques. Three anthropomorphic head phantoms (1-yr-old, 5-yr-old, and adult) were used. Images were acquired using four modes (Default protocol, OBTCM, SPS, and SPS+OBTCM). Absorbed dose to the lens, anterior brain (brain_A), and posterior brain (brain_P) was measured and compared. Image noise and CNR were assessed in the selected regions of interest (ROIs). Compared with that in the Default protocol, the absorbed dose to the lens reduced by up to 28.33%,71.38%, and 71.12% in OBTCM, SPS, and SPS+OBTCM, respectively. The noise level in OBTCM slightly (≤1.45HU) increased than that in Default protocol, and the SPS or SPS+OBTCM mode resulted in a quantitatively small increase (≤2.58HU) in three phantoms. There was no significant difference in CNR of different phantoms under varies scanning modes (p > 0.05). During head CT examinations, the SPS mode can reduce the radiation dose while maintaining image quality. SPS+OBTCM couldn't further effectively reduce the absorbed dose to the lens for 1-yr and 5-yr-old phantoms. Thus, SPS mode in pediatric and SPS+OBTCM mode in adult are better than other modes, and should be used in clinical practice.

Design Analysis of Amended PIFA with Ferrite Sheet Attachment for SAR Reduction in Human Head

Design Analysis of Amended PIFA with Ferrite Sheet Attachment for SAR Reduction in Human Head

Iterative Metal Artifact Reduction in Head and Neck CT Facilitates Tumor Visualization of Oral and Oropharyngeal Cancer Obscured by Artifacts From Dental Hardware

The purpose of this study was to evaluate the diagnostic utility of iterative metal artifact reduction (iMAR) in computed tomography (CT)-imaging of oral and oropharyngeal cancers when obscured by dental hardware artifacts and to determine the most appropriate iMAR settings for this purpose. The study retrospectively enrolled 27 patients (8 female, 19 male; mean age 64±12.7years) with histologically confirmed oral or oropharyngeal cancer obscured by dental artifacts in contrast-enhanced CT. Raw CT data were reconstructed with ascending iMAR strengths (levels 1/2/3/4/5) and one reconstruction without iMAR (level 0). For subjective analysis, two blinded radiologists rated tumor visualization and artifact severity on a five-point Likert scale. For objective analysis, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and artifact index (AI) were determined. iMAR reconstructions improved the subjective image quality of tumor edge and contrast, and the objective parameters of tumor SNR and CNR, reaching their optimum at iMAR levels 4 and 5 (P<.001). AI decreased with iMAR reconstructions reaching its minimum at iMAR level 5 (P<.001). Tumor detection rates increased 2.4-fold with iMAR 5, 2.1-fold with iMAR 4, and 1.9-fold with iMAR 3 compared to reconstructions without iMAR. Disadvantages such as algorithm-induced artifacts increased significantly with higher iMAR strengths (P<.05), reaching a maximum with iMAR 5. iMAR significantly improves CT imaging of oral and oropharyngeal cancers, as confirmed by both subjective and objective measures, with best results at highest iMAR strengths.

Numerical modeling constrained by environmental isotopes for sustainable development of partially renewable aquifers in desert area

Sustainable groundwater resources are a critical issue for national development in developing countries like Egypt, which is characterized by a semi-arid to arid climate and low per capita share of fresh water as a result of progressive population increase and especially after the construction of the Great Ethiopian Renaissance Dam. It is mandatory to adopt and modify methods suitable for preserving and efficient use of available water resources. The Eocene carbonate aquifer in the desert area under study (West El-Minia, Mid-Upper Egypt) is partially renewable; its sustainable development in irrigation is explored in this work. The (recharge–withdraw–exploit) regimes have been optimized by keeping the well abstraction below the fraction of renewable recharge and maximizing the exploit by selecting low water -consuming crops of high economic value. A novel approach is introduced in this work by integrating isotope hydrology techniques with numerical modeling; environmental isotopes (18O and D) contents of 62 groundwater samples have been used to determine and map the contribution of recent recharge in the study area (from 10 to 95%) and to constrain the acceptable reduction in hydraulic head allowed under an optimized withdraw and usage regime. Different scenarios were proposed by changing (rate of pumping, number of wells, wells distribution and irrigated crops) and simulating aquifer behavior to achieve the sustainable yield goals and the best plan for groundwater management in the study area.Graphical abstract

Surgical Training for a Disaster: Preparation of Surgical Trainees for Victims of Conflict.

With increasing global unrest and military physician shortages potentially leading to a surgeon draft, we sought to evaluate the readiness of graduating general surgery residents to care for casualties of war. We evaluated the National Data Reports of Surgery Case Logs for general surgery residents from 2009 to 2018 to quantify experience with key procedures that provide critical skills required for wartime surgery. Reported cases from the Accreditation Council for Graduate Medical Education for graduating residents from civilian and military residency programs were analyzed for 28 individual procedures determined to be critical for the care of combat casualties. These included central and peripheral vascular procedures, as well as neck, thoracic, abdominal, and peripheral interventions. From 2009 to 2018, there has been a significant decrease in wartime-relevant cases by graduating residents. Notably, these include aorto-iliac/femoral bypasses (50% reduction; 7.1%/year; P < .001), femoral-popliteal bypasses (60% reduction; 6.9%/year; P < .001), femoral-femoral bypasses (30% reduction; 2.6%/year; P < .001), upper extremity amputations (50% reduction; 6.4%/year; P = .016), fasciotomies for trauma (50% reduction; 4.5%/year; P = .013), open repair of ruptured infrarenal aorto-iliac aneurysms (70% reduction; 5.8%/year; P < .001), repair of traumatic aorta or vena cava injuries (70% reduction; 7%/year; P = .007), carotid endarterectomies (40% reduction; 4%/year; P < .001), lung resections (40% reduction; 3.7%/year; P = .001), trauma splenectomies/splenorrhaphy (30% reduction; 2.9%/year; P < .001), and repair of traumatic liver lacerations (30% reduction; 2.5%/year; P = .036). Graduating general surgery residents has limited exposure to wartime critical skills due to a significant reduction in open vascular, head and neck, thoracic, and operative trauma cases. As the threat of global war persists and new graduates continue to deploy worldwide, residency training must be augmented to ensure adequate preparation in case a surgeon draft is required to fulfill demand for military surgeons.

Study on Inflow Distortion Mechanism and Energy Characteristics in Bidirectional Axial Flow Pumping Station

In the present work, unsteady flow solved by the Reynolds time-averaged Navier–Stokes equation was investigated to determine the inflow distortion mechanism and the spatial distribution of hydraulic loss in a bidirectional axial flow pumping station (Case 1) based on the entropy production theory. A laboratory-scale performance experiment was also employed for the accuracy verification of the simulation approach, and an axial flow pump with pipe passages (Case 2) accompanying uniform inflow was utilized for analysis comparison. The results show that the non-uniform inflow causes a noticeable reduction in head and efficiency, as high as 27% and 21%, respectively, and the best efficiency point with uniform inflow shifts to the point with a larger flow rate. The axial velocity of the impeller inlet in Case 2 changes more smoothly along the Span compared with that in Case 1, which further indicates a more uniform inflow at the impeller inlet. The total entropy production (TEP) of each domain in Case 1 is always higher than that in Case 2, and the TEP of the whole domain in Case 1 increased by 18.68%, 30.50%, and 29.67% with flow rates of 0.8Qdes, 1.0Qdes, and 1.2Qdes, respectively, compared with that in Case 2. In the inlet passage, the larger TEPR regions in Case 1 are mainly located in the horn passage, which is far away from the inlet side, and are also distributed in the suction side of impeller blades and guide vanes. Therefore, this work may provide an optimal design reference for pumping stations in practical application.

Dehydration Reduction in Head and Neck Cancer (DRIHNC) Trial: Daily Oral Fluid and Electrolyte Maintenance to Prevent Acute Care Clinic and Emergency Department Visits for Patients Receiving Radiation for Head and Neck and Esophageal Cancer

PurposePatients with head and neck (H&N) and esophageal cancer are at high risk for treatment-related symptomatic dehydration, often leading to interventions and hospital admissions. We tested the hypothesis that preemptive daily oral hydration during curative-intent radiation therapy would decrease dehydration as measured by intravenous fluid (IVF) delivery, acute care clinic (ACC) visits, and emergency department (ED) presentations. Methods and MaterialsPatients with H&N or esophageal cancer undergoing definitive radiation therapy were enrolled in this prospective pilot study. Beyond standard nutritional counseling, patients were given one 20-oz bottle of an electrolyte-infused solution (EIS) daily throughout treatment. Compliance, presentations to the hospital ACC and/or ED for dehydration-related indications, and IVF infusions were documented and compared with a matched contemporary control cohort. The incidence and frequency of outcomes were compared with the Fisher exact test and Wilcoxon rank-sum test, respectively. ResultsThirty-one patients were compared during a 6-month period. Mean and median compliance rates were 87.4% and 100%, respectively. There were 0 unplanned dehydration-related ED presentations in the study group versus 3 (9.7%) among controls (P = .08). Of patients in the intervention cohort, 32.3% required presentation to the ACC, versus 64.5% in the control cohort (P = .02), with a total of 26 versus 117 visits, respectively (P = .002). On multivariable analysis, receipt of the EIS in the intervention cohort was the only significantly associated factor (P = .02). Among patients in the intervention cohort, 35.5% required IVF during treatment, versus 64.5% among controls (P = .004). The difference in ACC visits (P = .003) and IVF received (P = .008) was especially notable among patients with esophageal cancer. Patients with ≥60% EIS compliance had slightly fewer ACC visits versus those with <60% compliance (P = .067). ConclusionsRegimented oral hydration during radiation for H&N and esophageal cancer was associated with a significant decrease in ACC visits and IVF delivery during definitive radiation therapy. This noninvasive and inexpensive preventative program in a high-risk cohort warrants further study.

The effect of a moderately reclined seat-back angle on the kinematics of the Large-Omnidirectional Child Anthropomorphic Test Device with and without a belt-positioning booster in frontal crashes

Objective The effect of reclined seatbacks during frontal crashes in children seated on a belt-positioning booster (BPB) is not understood. Therefore, the aim of this study is to examine submarining in reclined child occupants with and without a BPB and with and without a simulated pre-pretensioner (PPT). We used the Large Omnidirectional Child (LODC) Anthropomorphic Test Device (ATD) seated on a production vehicle seat with and without a moderately reclined seatback angle during sled-simulated frontal vehicle crashes. Methods Ten sled-simulated frontal impact tests were performed (24 g peak, 80 ms duration, 56 km/h delta-V). An adjustable D-ring anchor simulated a seat integrated belt. A fixed load-limited 3-point seatbelt webbing system was used to secure the LODC to a vehicle seat and booster seat. We compared the following conditions: a) BPB vs no-BPB and b) 25° versus 45° seatback angles, c) PPT, vs no-PPT in 45° seatback condition, each test was repeated. Abdominal forces (left and right), seatbelt loads, Anterior-Superior-Illiac-Spine forces (ASIS, upper and lower, left and right), and pelvis rotation were analyzed. Results Average peak abdominal pressures were smaller in both nominal and moderate recline positions in the BPB (25°: 73.7 kPa, 45°: 82.5 kPa) compared to the no-BPB conditions (25°: 168.4 kPa, 45°: 339.1 kPa). In the 45° recline no-BPB conditions, both the peaks of the lap belt force and ASIS forces occurred early and a rapid reduction in those forces followed. This change in the lap belt and ASIS forces accompanied a rearward rotation of the pelvis. During the reduction of ASIS and lap belt forces, there was an increase in abdominal pressure suggesting that the lap belt moved upward, off the ASIS, and into the abdominal pressure sensor. There was a slight reduction in head and knee excursion with the PPT. These results suggest the presence of submarining in the 45° recline no-BPB conditions but not in the 45° recline with the BPB. Conclusions The BPB could be beneficial when the seatback is moderately reclined. The differences during the moderate recline between the BPB and no-BPB conditions also indicate that the BPB could prevent submarining in moderately reclined seats.

Radiation Dose Reduction in Head and Neck Computed Tomography Angiography.

The study aims to investigate the feasibility of further radiation dose reduction via the application of a high iodine delivery rate combined with automatic current modulation technology (high noise index) in head and neck computed tomography angiography. Sixty-four patients who underwent routine head and neck computed tomographic angiography were randomly divided into two groups: a low-dose group of 32 cases and an ultra-low-dose group of 32 cases. The same image reconstruction technique was applied in both groups using the 50% adaptive statistical iterative reconstruction method. Quantitative and qualitative image quality assessment of the carotid artery, computed tomographic dose index volume, dose length product, and effective dose of the two groups were analyzed. The two groups were not significantly (P>0.05) different in age, gender, and body mass index. Significant (P<0.001) reduction of radiation dose was observed in all the parameters of computed tomographic dose index volume (18.12%), dose length product (19.91%), and effective dose (19.84%) in the ultra-low-dose group. Quantitative and qualitative image assessment produced similar results between the two groups, except for the higher mean vascular computed tomographic values found in the ultra-low dose group. Application of a higher iodine delivery rate combined with automatic current modulation technology (high noise index) in an existing low tube voltage protocol can further decrease the radiation dose and the total volume of contrast agent while maintaining similar image quality for patients undergoing computed tomography angiography of the head and neck, which can be recommended as the conventional scanning method.

Numerical Simulation of Mechanical Coupling for Low-Back Booster with a 6-Year-Old Child during a Crash Test

This research assessed a mechanical coupling for the ISOFIX Child Restraint System using the Finite Element Method (FEM) in a critical condition (simultaneous frontal and lateral collision). The mechanism was designed according to the R129 standard, and it consists of a set of springs and dampers that allows displacements in the three Cartesian axes (x, y, z) to dissipate a portion of the energy produced by a traffic accident. Two case studies are presented. The first one evaluates the behavior of the mechanism by applying the equivalent weight of a child and the LBB during a frontal and lateral impact according to the FMVSS 213 standard. The second evaluates the injuries generated in the head, neck, and thorax with a six-year Hybrid III model during a frontal impact when implementing the coupling system. The outcomes show that both axes reach a maximum deceleration of 23 G, and it remains from 17 G to 21 G in 30 ms. After 65 ms, it decreases from 17 G to 0 G. Overall, the injury rates are compared when using mechanical coupling with LBB and only LBB to analyze the system’s efficiency, showing a significant reduction in head and neck injuries, obtaining a 24% variation in the HIC36, and reducing the neck range motion by 19.3°.