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In recent years, additive manufacturing has increased in prominence as a primary method of manufacturing around the globe. Modern metal additive manufacturing presents an innovative approach to manufacturing complex structures for the aerospace, energy, and construction sectors, due to technological advancements. In the present study, the austenitic stainless steel 309L (SS-309L) thick wall component was manufactured employing pulsed current gas tungsten arc welding (PC-GTAW) WAAM technology. The metallurgical characteristics of the as-deposited SS-309L thick wall part were evaluated. The investigation of material characteristics in the manufactured areas encompasses a study of cross-sectional (CS) and transverse-sectional (TS) regional portions, specifically the upper, middle, and lower regions. The microstructures of the CS and TS planes showed austenite, columnar, and delta ferrite dendrites in the upper, middle, and lower regions, respectively. The CS sample reveals the greatest grain size at 159.4 μm, following the EBSD investigation. The average size of the grains across the TS is 127.09 μm. The thermal cycles in multi-layer production result in changes in grain size. The microhardness in the transverse sectional regions is higher than in the CS regions, measuring average values of 257 HV, 253 HV, and 251 HV for the upper, middle, and lower sections, respectively. The ultimate tensile strengths (UTS) in the cross-sectional parts are 656 MPa, whereas in the transverse regions it was 661 MPa for the topmost regions. This study investigates the correlation among the mechanical and metallurgical properties of wire arc additively fabricated SS-309L austenite steel material.

In this work, an investigation was made to analyze the surface residual stresses on additive manufactured stainless steel AISI 316L in as-built and post-treated conditions. Direct metal laser sintering was used to fabricate the metal blocks. X-ray residual stress analysis on the as-fabricated surface revealed the presence of an inhomogeneous and irregular distribution of residual stresses in the as-built condition ranging from - 30 MPa to 111 MPa. It was mainly due to the localized laser heat source that caused variations in stresses at a lattice level. Heat treatment was performed for providing relief to the residual stress from the as-built condition showed significant relief of residual stress, which was lesser than 50% compared to as-built condition. Beneficial compressive residual stress induced by shot peening and lapping resulted in high magnitude compressive stresses on the surface. Also, homogeneous distribution of residual stress was found on the peened and lapped surface layer with an average of - 531 MPa and - 554 MPa, respectively.

Introduction: Alpha blockers are widely used in the treatment of primary bladder neck obstruction; however, evidence for objective urodynamic efficacy is scarce. We studied the effect of the uroselective α1-blocker tamsulosin on urodynamic parameters in male patients with type I primary bladder neck obstruction. Methods: A single center prospective observational study was carried out from July 2013 to February 2015. Male patients (18–50 years) with type 1 primary bladder neck obstruction were recruited. Selected patients were started on tablet tamsulosin 0.4 mg once daily for 3 months. International prostate symptom score (IPSS), uroflow and urodynamic studies were done pre- and post-treatment. Primary outcome was decreased in minimum detrusor pressure at maximum flow rate by 15%. Wilcoxon-matched pair signed-rank test was used. Results: Of 39 patients recruited, 21 patients completed the follow-up as per protocol and were analyzed. Mean age was 41 years. 57% patients achieved the primary outcome (median detrusor pressure pre- and post-treatment were 71 and 56 cm of water, P < 0.001). Similarly, median values for bladder outlet obstruction index (BOOI) and IPSS decreased from 59 to 38 (P < 0.001) and 22 to 12 (P < 0.001), respectively. Median maximum flow rate increased from 8 to 10 ml (P = 0.05). Pretreatment BOOI of >60 was associated with poor outcomes. Conclusions: Tamsulosin 0.4 mg once a day is effective in reducing bladder outlet obstruction on pressure flow studies in patients with primary bladder neck obstruction type 1.

Temperature rise in multi-junction solar cells reduces their efficiency and shortens their lifetime. We report the results of the feasibility study of passive thermal management of concentrated multi-junction solar cells with the non-curing graphene-enhanced thermal interface materials. Using an inexpensive, scalable technique, graphene and few-layer graphene fillers were incorporated in the non-curing mineral oil matrix, with the filler concentration of up to 40 wt% and applied as the thermal interface material between the solar cell and the heat sink. The performance parameters of the solar cells were tested using an industry-standard solar simulator with concentrated light illumination at 70× and 200× suns. It was found that the non-curing graphene-enhanced thermal interface material substantially reduces the temperature rise in the solar cell and improves its open-circuit voltage. The decrease in the maximum temperature rise enhances the solar cell performance compared to that with the commercial non-cured thermal interface material. The obtained results are important for the development of the thermal management technologies for the next generation of photovoltaic solar cells.

Competing Interests: Declaration of competing interest The authors have no conflicts of interest to disclose.

Background: Severe coronavirus disease 2019 (COVID-19) may require veno-venous extracorporeal membrane oxygenation (V-V ECMO). While V-V ECMO is offered in severe lung injury to COVID-19, long-term respiratory follow-up in these patients is missing. Therefore, we aimed at providing comprehensive data on the long-term respiratory effects of COVID-19 requiring V-V ECMO support during the acute phase of infection., Methods: In prospective observational cohort study design, patients with severe COVID-19 receiving invasive mechanical ventilation and V-V ECMO (COVID group, n = 9) and healthy matched controls ( n = 9) were evaluated 6 months after hospital discharge. Respiratory system resistance at 5 and 19 Hz (R 5 , R 19 ), and the area under the reactance curve (AX 5 ) was evaluated using oscillometry characterizing total and central airway resistances, and tissue elasticity, respectively. R 5 and R 19 difference (R 5 -R 19 ) reflecting small airway function was also calculated. Forced expired volume in seconds (FEV 1 ), forced expiratory vital capacity (FVC), functional residual capacity (FRC), carbon monoxide diffusion capacity (DLCO) and transfer coefficient (KCO) were measured., Results: The COVID group had a higher AX 5 and R 5 -R 19 than the healthy matched control group. However, there was no significant difference in terms of R 5 or R 19 . The COVID group had a lower FEV 1 and FVC on spirometry than the healthy matched control group. Further, the COVID group had a lower FRC on plethysmography than the healthy matched control group. Meanwhile, the COVID group had a lower DLCO than healthy matched control group. Nevertheless, its KCO was within the normal range., Conclusion: Severe acute COVID-19 requiring V-V ECMO persistently impairs small airway function and reduces respiratory tissue elasticity, primarily attributed to lung restriction. These findings also suggest that even severe pulmonary pathologies of acute COVID-19 can manifest in a moderate but still persistent lung function impairment 6 months after hospital discharge., Trial Registration: NCT05812196., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Pálfi, Balogh, Polónyi, Schulcz, Zöllei, Bari, Fodor, Baráth, Somfay, Peták and Babik.)

Background: Video-oculography (VOG) is used to quantify functional deficits in internuclear ophthalmoplegia (INO), whereas MRI can detect the corresponding structural lesions in the medial longitudinal fasciculus (MLF). This study investigates the diagnostic agreement of MRI compared to VOG measurements., Methods: We prospectively compared structural MRI findings and functional VOG measures of 63 MS patients to assess their diagnostic agreement for INO., Results: MRI detected 12 true-positive and 92 true-negative MLF lesions for INO compared to VOG (12 true-positive and 38 true-negative patients) but identified one-third of the MLF lesions on the wrong side. MRI ratings were specific (92.0%) to detect MLF lesions but not sensitive (46.2%) for diagnosing INO (86.4% and 63.2% by patient). Accordingly, MRI has a high positive likelihood ratio of 5.77 but a modest negative likelihood ratio of 0.59 for the probability of INO (4.63 and 0.43) with an accuracy of 82.5% (79.4%)., Conclusion: MRI assessments are highly specific but not sensitive for detecting INO compared to VOG. While MRI identifies MLF lesions in INO, VOG quantifies the deficit. As a simple, quick, and non-invasive test for diagnosing and tracking functional INO deficits, it will hopefully find its place in the diagnostic and therapeutic pathways of MS., (© 2022. The Author(s).)

Objectives: Cardiopulmonary exercise test (CPET) is a widely used examination to predict the prognosis of many chronic pulmonary diseases, and it has also been tested in systemic sclerosis (SSc) with a focus on the development of pulmonary hypertension. CPET is a highly informative non-invasive tool that provides a more complex information than conventional lung function tests to predict the course of cardiopulmonary diseases, as it provides a general overview of the aerobic metabolism, influenced by pulmonary, cardiovascular and peripheral muscle function. The purpose of this investigation was to assess if the progression and the development of poor overall disease outcome in SSc can be predicted by this method., Methods: Twenty-nine SSc patients were investigated prospectively with standard follow-up plus CPET for a mean of 3.7 years to match the results of conventional evaluation modalities and CPET. A composite end-point of several serious outcomes reflecting SSc-related vascular and cardiopulmonary damage was set up, and the predictive value of and correlations between the CPET parameters and resting lung function and echocardiography variables were assessed., Results: None of the clinical parameters, resting lung function or echocardiographic test results proved to be predictive of the development of the endpoint of poor prognosis in this cohort. In contrast, several CPET parameters were found to discriminate between SSc patients with or without adverse outcome. The detection of desaturation (at any CPET test) was associated with a higher risk of poor prognosis (OR:5.265). VO2 and VE/VCO2 at baseline correlated with the annual decrease in FVC, anaerobic threshold with the development of digital ulcers, and VE/VO2 with the increase in pulmonary arterial pressure., Conclusions: Several CPET parameters obtained at the beginning of follow-up are informative of the appearance of various adverse end-points. CPET is a feasible examination in the care of SSc patients and provides excess information to current standard follow-up examinations.

Introduction:: The aim of this study was to analyze the sensitivity and specificity of non-echoplanar (non-EPI) diffusion-weighted (DW) magnetic resonance imaging (MRI) for the detection of cholesteatoma, with a focus on its value as an adjunct to clinical examination., Methods:: In a prospective cohort study, 92 cases were divided into 2 groups: "clinically cholesteatoma" ( n = 79) and "clinically no cholesteatoma" ( n = 13). Non-EPI DW MRI was performed preoperatively in all cases. The presence of a cholesteatoma was assessed by clinicians otoscopically, by neuroradiologists on non-EPI DW MRI, by the surgeon intraoperatively, and finally by the pathologist postoperatively. Data analysis was performed for specificity, sensitivity, positive predictive value, negative predictive value, and interrater variability., Results:: The sensitivity and specificity were 89.3% and 75%, respectively, in the "clinically cholesteatoma" group and 0% and 100% in the "clinically no cholesteatoma" group. Non-EPI DW MRI had a positive predictive value of 98.5% when cholesteatoma was suspected clinically and a negative predictive value of 84.6% when cholesteatoma was not suspected clinically., Conclusion:: If cholesteatoma is suspected clinically, non-EPI DW MRI is not necessary. If there is no clinical suspicion of cholesteatoma in second-look situations, sensitivity is low and serial follow-up MRI with long intervals is advised.

Background. Funicular myelosis is a known consequence of exposure to nitrous oxide. Nevertheless, there are only a few clinical trials assessing its long-term effects and there is no literature about the role of nutritional vitamin B12 supplementation in the context of nitrous oxide abuse. Case Descriptions. We diagnosed funicular myelosis in a young butcher, who consumed high amounts of meat regularly. Since the diagnostic process did not reveal any metabolic causes, reinterrogation of the patient uncovered recreational abuse of nitrous oxide out of whipped cream can gas cartridges. After stopping abuse and supplementation of vitamin B12, the patient recovered almost completely. Conclusions. In our case, even high nutritional vitamin B12 uptake could not compensate the noxious effects of nitrous oxide. Since there are emerging reports of increasing misuse, this should be considered in the diagnostic and therapeutic care of patients with nitrous oxide abuse. Furthermore, our case emphasizes that patients with vitamin B12 deficiency should be assessed for nitrous oxide abuse.

Background and Purpose: Endolymphatic hydrops has been recognized as the underlying pathophysiology of Menière disease. We used 3T MR imaging to detect and grade endolymphatic hydrops in patients with Menière disease and to correlate MR imaging findings with the clinical severity., Materials and Methods: MR images of the inner ear acquired by a 3D inversion recovery sequence 4 hours after intravenous contrast administration were retrospectively analyzed by 2 neuroradiologists blinded to the clinical presentation. Endolymphatic hydrops was classified as none, grade I, or grade II. Interobserver agreement was analyzed, and the presence of endolymphatic hydrops was correlated with the clinical diagnosis and the clinical Menière disease score., Results: Of 53 patients, we identified endolymphatic hydrops in 90% on the clinically affected and in 22% on the clinically silent side. Interobserver agreement on detection and grading of endolymphatic hydrops was 0.97 for cochlear and 0.94 for vestibular hydrops. The average MR imaging grade of endolymphatic hydrops was 1.27 ± 0.66 for 55 clinically affected and 0.65 ± 0.58 for 10 clinically normal ears. The correlation between the presence of endolymphatic hydrops and Menière disease was 0.67. Endolymphatic hydrops was detected in 73% of ears with the clinical diagnosis of possible, 100% of probable, and 95% of definite Menière disease., Conclusions: MR imaging supports endolymphatic hydrops as a pathophysiologic hallmark of Menière disease. High interobserver agreement on the detection and grading of endolymphatic hydrops and the correlation of MR imaging findings with the clinical score recommend MR imaging as a reliable in vivo technique in patients with Menière disease. The significance of MR imaging detection of endolymphatic hydrops in an additional 22% of asymptomatic ears requires further study., (© 2014 by American Journal of Neuroradiology.)

The diagnosis, work-up, and treatment of sudden sensorineural hearing loss and sudden vestibular loss vary widely between units. With the increasing access to both magnetic resonance imaging and objective vestibular testing, our understanding of the various aetiologies at hand is increasing. Despite this, the therapeutic options are limited and without a particularly strong evidence base. We present a rare, yet increasingly diagnosed, case of intralabyrinthine haemorrhage (ILH) together with radiological, audiological, and vestibular test results. Of note, this occurred spontaneously and has shown partial recovery in all the mentioned modalities.

The relevant aspects of cholesteatomas are reviewed with the emphasis on their diagnosis by using cross-sectional imaging. The indications and limitations of CT and MR imaging and the use of novel MR imaging techniques in the diagnosis of cholesteatomas are described. HRCT of the temporal bone has an excellent spatial resolution, thus even small soft-tissue lesions can be accurately delineated (high sensitivity). However, CT has poor specificity (ie, soft-tissue structures cannot be differentiated). MR imaging with the conventional sequences (T1WI, T2WI, postcontrast T1WI) provides additional information for distinguishing different pathologic entities and for accurately diagnosing primary (nonsurgical) and residual/recurrent (surgical) cholesteatomas. Higher diagnostic specificity is achieved by introducing DW-EPI, delayed postcontrast imaging, DW-non-EPI, and DWI-PROPELLER techniques. Studies using DW-non-EPI and DWI-PROPELLER sequences show promising results related to improved diagnostic sensitivity and specificity for even small (<5 mm) cholesteatomas, thus allowing avoidance of second-look surgery in the future.

Objectives: Stent implantation across the neck of cerebral aneurysms may induce intra-aneurysmal flow reduction, and consequently saccular thrombosis and vessel wall repair. To analyse the influence of different stent parameters on such flow reduction, we studied the flow changes in vascular models, induced by a series of stents., Methods: Two different neck-sized elastic sidewall aneurysm models were connected to a circulatory loop. Twenty different stents were introduced in both models to analyse the effect of their parameters, such as porosity, filament diameter and permeability. Flow patterns were visualized by using glass particles and laser sheet translumination. The digitally recorded data were transferred for computer analysis. The changes of the vortex velocity for each stent model combination were investigated and statistically evaluated., Results: Intra-aneurysmal flow analysis showed dispersion of the vortices of a variable degree, and velocity reduction of 30% mean in model 1 and 49% mean in model 2. By statistical analysis three groups of stents ('best', 'medium', 'worst') were identified, according to their haemodynamic efficacy. No correlations were observed between the haemodynamic performance of the stents and the porosity, filament diameter and permeability values separately. The stent effects were on average more important in the large-necked than in the small-necked aneurysm model., Discussion: Stent implantation induces intra-aneurysmal loss of vortex coherence and flow reduction. The analysed stent parameters show complex interrelationship, including also stent 'design'. The difference in the haemodynamic efficacy of the individual stents between the two models raises the question of 'stent positioning effects'.

Background and Purpose: Stent implantation alone might not be sufficient to produce definitive treatment of cerebral aneurysms. Therefore, extended experimental work is needed to improve results. We show the feasibility of using an in vitro anatomically shaped elastic model for flow evaluation before and after stent implantation., Methods: Based on human vascular casting, an anatomic elastic internal carotid artery model, including an aneurysm on the supraclinoid portion, was manufactured. The model was connected to a circulatory loop to simulate physiological flow. After visualization of the flow by using glass particles and laser sheet translumination, the digitally recorded data were transferred for computer analysis. Intra-saccular flow pattern changes and the vortex velocity reduction induced by the stent were investigated qualitatively and quantitatively., Results: The distal neck of the aneurysm behaved as a flow divider. Therefore, it was directly exposed to the hemodynamic stress. Inside the sac, a well-defined vortex formed and progressed along the wall toward the proximal neck. After stent implantation this pattern changed significantly; the vortex appeared more dispersed and its residence time increased. The velocity reduction was 32%. Velocity peak was observed close to the distal neck in both cases., Conclusion: In vitro anatomic elastic models are feasible for flow evaluation with laser sheet translumination. In our model, stent implantation resulted in hemodynamic changes that might favor the exclusion of the aneurysm from the circulation and can prevent regrowth of the aneurysmal sac.

Percutaneous vertebroplasty (PVP) is a radiologically guided therapeutic procedure, which consists of percutaneous injection of a liquid polymer (bone cement) into a destroyed vertebral body. PVP was invented in 1984, in France, first for treating vertebral body haemangioma. Since its introduction the indications have been expanded progressively and today PVP is indicated mainly for treatment of vertebral haemangioma, malignant vertebral tumor and osteoporotic vertebral compression fracture. The unique advantage of this technique is that besides the stabilization of the vertebral body--and partly in connection with this--it affords prompt and lasting pain relief. Based on published data the success rate of the procedure is 80-100% with a complication rate of 1-10%. Thus, PVP is a valuable minimally invasive tool, providing immediate pain relief and early mobility in carefully selected patients. However, further work is needed to define the benefits of PVP compared to the standard treatment. The purpose of this paper is to demonstrate the technique by analyzing scientific reports published to date and summarizing the first author's own experience gained at the University Hospital of Geneva, Department of Neuroradiology, Switzerland.