Search

Abstract Background The growing concern for player safety in rugby has led to an increased focus on head impacts. Previous laboratory studies have shown that rugby headgear significantly reduces peak linear and rotational accelerations compared to no headgear. However, these metrics may have limited relevance in assessing the effectiveness of headgear in preventing strain-based brain injuries like concussions. This study used an instantaneous deep-learning brain injury model to quantify regional brain strain mitigation of rugby headgear during drop tests. Tests were conducted on flat and angled impact surfaces across different heights, using a Hybrid III headform and neck. Results Headgear presence generally reduced the peak rotational velocities, with some headgear outperforming others. However, the effect on peak regional brain strains was less consistent. Of the 5 headgear tested, only the newer models that use open cell foams at densities above 45 kg/m3 consistently reduced the peak strain in the cerebrum, corpus callosum, and brainstem. The 3 conventional headgear that use closed cell foams at or below 45 kg/m3 showed no consistent reduction in the peak strain in the cerebrum, corpus callosum, and brainstem. Conclusions The presence of rugby headgear may be able to reduce the severity of head impact exposure during rugby. However, to understand how these findings relate to brain strain mitigation in the field, further investigation into the relationship between the impact conditions in this study and those encountered during actual gameplay is necessary.

Background: The growing concern for player safety in rugby has led to an increased focus on head impacts. Previous laboratory studies have shown that rugby headgear significantly reduces peak linear and rotational accelerations compared to no headgear. However, these metrics may have limited relevance in assessing the effectiveness of headgear in preventing strain-based brain injuries like concussions. This study used an instantaneous deep-learning brain injury model to quantify regional brain strain mitigation of rugby headgear during drop tests. Tests were conducted on flat and angled impact surfaces across different heights, using a Hybrid III headform and neck. Results: Headgear presence generally reduced the peak rotational velocities, with some headgear outperforming others. However, the effect on peak regional brain strains was less consistent. Of the 5 headgear tested, only the newer models that use open cell foams at densities above 45 kg/m3 consistently reduced the peak strain in the cerebrum, corpus callosum, and brainstem. The 3 conventional headgear that use closed cell foams at or below 45 kg/m3 showed no consistent reduction in the peak strain in the cerebrum, corpus callosum, and brainstem. Conclusions: The presence of rugby headgear may be able to reduce the severity of head impact exposure during rugby. However, to understand how these findings relate to brain strain mitigation in the field, further investigation into the relationship between the impact conditions in this study and those encountered during actual gameplay is necessary. [ABSTRACT FROM AUTHOR]

Background: Hyperthyroidism in humans is associated with a hypercoagulable state and an increased risk of thromboembolism. Objective: To evaluate hemostatic variables in hyperthyroid and euthyroid cats with the hypothesis that hyperthyroid cats will have evidence of altered hemostasis consistent with a potential hypercoagulable state. Animals: Client‐owned hyperthyroid (n = 16) and euthyroid (n = 15) cats over 8 years of age. Methods: Prospective observational study. Hyperthyroid and euthyroid cats were enrolled. Rotational thromboelastometry (ROTEM), whole‐blood platelet impedance aggregometry (WBPIA) and a point‐of‐care viscoelastic coagulation monitor (VCM‐Vet) were performed immediately after minimally traumatic venipuncture under sedation. Results: Hyperthyroid cats had significantly higher values for variables as assessed by VCM‐Vet: A10 (34 [17‐47] vs 25 [17‐38], P =.003); A20 (39.5 [23‐55] vs 31 [21‐45], P =.003); and MCF (41 [24‐58] vs 35 [22‐49], P =.03). Hyperthyroid cats had significantly different values versus the euthyroid cohort as assessed by different ROTEM channels: increased A10, INTEM (61.5 [39‐75] vs 54 [23‐66], P =.007) and FIBTEM (18 [10‐35] vs 13 [2‐27], P =.01); increased A20, INTEM (68 [45‐78] vs 61 [30‐70], P =.006) and FIBTEM (17 [10‐34] vs 11 [2‐25], P =.002); increased MCF, EXTEM (72 [65‐81] vs 69 [34‐78], P =.04), INTEM (70 [45‐85] vs 62 [35‐71], P =.01) and FIBTEM (18 [13‐37] vs 14 [3‐27], P =.02); increased alpha angle, EXTEM (80 [68‐85] vs 76 [41‐84], P =.01); shortened CT, EXTEM (52.5 [29‐73] vs 60 [52‐92], P =.003) and FIBTEM (52.5 [16‐75] vs 65 [53‐165], P =.001); and decreased ML, FIBTEM (20 [1‐36] vs 33 [19‐59], P <.001). No significant differences were found with WBPIA. Conclusions and Clinical Importance: The hyperthyroid cats in this study had evidence of altered hemostasis as assessed by 2 viscoelastic methodologies, and characterized by increased clot amplitude, firmness, and faster coagulation times vs euthyroid controls. [ABSTRACT FROM AUTHOR]

Wood is a preferred material for constructing staircases due to its appealing aesthetic features. The use of wood, especially hardwoods such as red oak (Quercus rubra), white oak (Quercus alba), yellow poplar (Liriodendron tulipifera), and hard maple (Acer saccharum), has been the main construction material for staircases over the years. Staircase designs have evolved because of the flexibility of wood and working with specialized manufacturing machinery. A stair guard system connection must be designed to resist rotational and translational movements whenever a force is applied to the handrail. The demand for structural design values in wooden stair guards has been steadily increasing, driven by the needs of engineers, designers, builders, and end-users alike. This paper presents experimental data for four stair guard connections (post-to-rail, infill-to-footing, infill-to-rail, and rail-to-rail) encountered in a hardwood stairway handrail guard system. The data generated from this research could be useful for modeling the structural behavior of the connections.

Wood is a preferred material for constructing staircases due to its appealing aesthetic features. The use of wood, especially hardwoods such as red oak (Quercus rubra), white oak (Quercus alba), yellow poplar (Liriodendron tulipifera), and hard maple (Acer saccharum), has been the main construction material for staircases over the years. Staircase designs have evolved because of the flexibility of wood and working with specialized manufacturing machinery. A stair guard system connection must be designed to resist rotational and translational movements whenever a force is applied to the handrail. The demand for structural design values in wooden stair guards has been steadily increasing, driven by the needs of engineers, designers, builders, and end-users alike. This paper presents experimental data for four stair guard connections (post-to-rail, infill-to-footing, infill-to-rail, and rail-to-rail) encountered in a hardwood stairway handrail guard system. The data generated from this research could be useful for modeling the structural behavior of the connections. [ABSTRACT FROM AUTHOR]

Endovascular treatment of the common femoral artery (CFA) and its branches is often challenging. Sometimes, stent placement cannot be avoided. Furthermore, stent placement in this area carries several risks for complications. We present a challenging case in which we used a rotational atherectomy device percutaneously in cross-over-technique to recanalize the external iliac artery in combination with the femoral bifurcation, all in one session - and - without the need for a femoral stent in a multimorbid patient. We also tried to gain more insights in the patient's perspective and we took a validated health status evaluation into account. The patient was presented due to chronic open wounds on the left foot for months (Stadium Fontaine IV). Duplex sonography and CT angiography showed a complete occlusion of the left external iliac artery with involvement of the left common femoral artery. Due to the pre-existing chronic diseases and the high risk of prolonged anesthesia, the patient was not suitable for open reconstruction of the common femoral artery. We aimed for endovascular therapy using a crossover maneuver to minimize anesthesia time as much as possible. The percutaneous treatment was performed with a rotational atherectomy device and drug-coated balloon angioplasty with satisfying angiographic results and complete blood-flow restoration. No peri-procedural complications occurred. We gained experience with this endovascular-treatment-device in our teaching hospital and more difficult cases can now be treated. The patient's perspective and health status were assessed during follow-up visit. The endovascular treatment of severe calcifications in peripheral arterial occlusive disease (PAOD) seems to be a good solution for selected patients, significantly minimizing surgical trauma. The newly combined rotational atherectomy and thrombectomy devices have demonstrated positive outcomes in areas where conventional treatment has traditionally been the standard. The groin types of peripheral arterial occlusive disease (PAOD) are quite often challenging to operate. Open treatment of the common femoral artery has been the standard procedure until modern endovascular possibilities provide a new concept in this treatment, emphasizing a minimal invasive approach in multi morbid patients. The case description results in an illustrated follow up period of 6 months and is presented in line with the recommendations of the consensus-based surgical case reporting guideline development. Managing peripheral arterial occlusive disease in the groin region poses a continual challenge. Traditionally, open treatment of the common femoral artery has been - and is - the established procedure. However, contemporary endovascular options now introduce a new paradigm in this treatment, highlighting minimally invasive approaches in multi morbid patients and its patient satisfaction. • In this case we describe a complete percutaneous crossover revascularisation. • Fontaine IV wound, without any healing trend was treated in a multimorbid vascular patient. • The importance of this endovascular technique may contribute to the armamentarium of every (endo)vascular surgeon. [ABSTRACT FROM AUTHOR]

Herein, we report a spectroscopic study of N-acetyl-L-cysteine, an important antioxidant drug, using Fourier-transform microwave techniques and in isolated conditions. Two conformers are observed, where most stable structure adopts a cis disposition, and the second conformer has a lower abundance and adopts a trans disposition. The rotational constants and the barriers to methyl internal rotation are determined for each conformer, allowing a precise conformation identification. The results show that the cis form adopts an identical structure in the crystal, solution, and gas phases. Additionally, the structures are contrasted against those of cysteine., (© 2024 Wiley-VCH GmbH.)

This study systematically reviews 62 papers on the use of rotational rheometry to assess the fresh state behavior of Portland cement-based materials. The research highlights the wide variation in test methods and aims to provide a comprehensive overview. Findings reveal that 50.0% of studies employed vane geometry, despite its limitations in providing transformation equations. Regarding dynamic shearing tests, 67.0% followed a consensus using a pre-shearing step and a step-wise routine with stabilization times ≥ 10 s. While the Bingham model is commonly used, the study emphasizes the importance of considering shear-thinning behavior in cementitious materials. Models like Herschel-Bulkley and modified Bingham may be more appropriate. This review offers insights into testing conditions for rotational rheometry of cementitious materials, serving as a foundation for future research in the field. • The 62 papers that conducted rotational rheometry trials were systematically reviewed. • The Vane rotor type is the most employed geometry in studies. • There was a trend of step test protocols with stabilization times of at least 10 seconds. [ABSTRACT FROM AUTHOR]