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Additive manufacturing (AM) is treated as a significant contributor to sustainability due to lower energy consumption, less material usage and reduced number of wastes generated when comparing with traditional manufacturing technologies. Currently there is a lot of commercial applications of such new technology in number of industry segments. However, such sector as high voltage engineering still struggles with number of challenges when considering additive manufacturing. In products working in high voltage environment, very often, in addition to mechanical loads there are demanding conditions, as elevated temperature and presence of insulation oil or gas. This requires a special approach to printing quality of the printed structures without internal voids and in case of metals, with improved electrical conductivity. In the paper, few examples of additive manufacturing applications in area of power products have been presented, including printed transformer insulation, printed copper, and application of AM for spare parts. For each case, the main challenges have been discussed.

Plastics are widely used materials, and their application increases considerably every year. Therefore, appropriate waste management policy should be used in relation to utilization/recycling of scrap plastic components. Currently, there are no clear utilization options for such scrap thermosetting materials, and landfill is the most commonly used method of their removal. However, it should be underlined that, in various products, especially from the electrotechnics industry, different metals are embedded in cured thermosets, and their recovery could be a very valuable recycling operation. Also, new environmental regulations are developing in this direction in that landfilling of organic wastes will be essentially limited. In this article, the results of the preliminary studies on pyrolytical degradation of thermosetting scrap have been presented, proving that this kind of waste treatment results in valuable pyrolysis products, and, as an additional benefit, recycling of the internal metallic parts can be successfully achieved. [ABSTRACT FROM AUTHOR]

The paper presents application of newly developed three-dimensional (3-D) computer tool used for simulation of the automated pressure gelation process. The tool that is based on commercial CFD software-Fluent-enables the simulation of filling and curing stages and gives useful information helping to understand the phenomena occurring inside the mold. To simulate the complex rheology of the material, Macosko's model for viscosity and Kamal's model for curing kinetics were used and successfully applied in the software. First simulations were applied for arbitrary set parameters and formulated recommendations were later applied to approve the existing process. The simulation was performed for voltage transformer used in medium voltage applications and resulted in the optimization of the process parameters what allowed reduction of manufacturing time of the transformer considerably. Additionally the results of experimental verification of the simulation were presented in the paper showing very good agreement between simulation results and measured data. [ABSTRACT FROM PUBLISHER]

Abstract Background Chiari I malformation (CMI) is diagnosed by rigid radiographic criteria along with appropriate clinical symptomatology. The aim of this study was to investigate the dimensions of the posterior cranial fossa in patients without significant tonsillar descent but with symptoms comparable to CMI. Methods Twenty-two patients with signs and symptoms comparable to CMI but without accepted radiographic criteria of tonsillar descent > 3–5 mm were referred to our clinic for evaluation. A history and physical examination were performed on all patients. In reviewing their MRI scans, nine morphometric measurements were recorded. The measurements were compared to measurements from a cohort of twenty-five individuals with cranial neuralgias from our practice. Results For patients with Chiari-like symptomatology, the following statistically significant abnormalities were identified: reduced length of the clivus, reduced length of basisphenoid, reduced length of basiocciput, and increased angle of the tentorium. Multiple morphometric studies have demonstrated similar findings in CMI. Conclusion The current classification of CMI is likely too restrictive. Preliminary morphologic data suggests that a subgroup of patients exists with tonsillar descent less than 3 mm below the foramen magnum but with congenitally hypoplastic posterior fossa causing symptomatology consistent with CMI.

Three-dimensional printing technology is constantly developing and has a wide range of applications; one application is electrical insulation, where the standard technology uses polymer-based filaments. Thermosetting materials (epoxy resins, liquid silicone rubbers) are broadly used as electrical insulation in high-voltage products. In power transformers, however, the main solid insulation is based on cellulosic materials (pressboard, crepe paper, wood laminates). There are a vast variety of transformer insulation components that are produced using the wet pulp molding process. This is a labor-intensive, multi-stage process that requires long drying times. In this paper, a new material, microcellulose-doped polymer, and manufacturing concept for transformer insulation components are described. Our research focuses on bio-based polymeric materials with 3D printability functionalities. A number of material formulations were tested and benchmark products were printed. Extensive electrical measurements were performed to compare transformer components manufactured using the traditional process and 3D printed samples. The results are promising but indicate that further research is still required to improve printing quality.

Background and Purpose: Classic trigeminal neuralgia is a clinical syndrome of facial pain, most often attributable to vascular compression of the proximal cisternal segment of the trigeminal nerve and treatable with microvascular decompression of the nerve. Some patients, however, meet all clinical criteria for classic trigeminal neuralgia yet do not respond to microvascular decompression. Because the reasons for surgical failure are not well understood, the aim of this study was to determine if a subset of patients with classic trigeminal neuralgia could be distinguished by measuring the angle of the trigeminal nerve in the sagittal plane as the nerve traverses the porus trigeminus., Materials and Methods: We retrospectively identified patients with either classic trigeminal neuralgia ( n = 300) or hemifacial spasm ( n = 300) who had undergone MR imaging, including 3-plane steady-state free precession imaging. Patients with hemifacial spasm served as controls. On sagittal steady-state free precession images, we measured the angle of each trigeminal nerve as it crosses through the porus trigeminus into the Meckel cave (SATNaPT). In patients with classic trigeminal neuralgia, we separated the nerves into symptomatic and asymptomatic sides. We compared these 3 groups using the Student t test., Results: Control patients had a mean SATNaPT of 170° (SD, 11°) with a normal distribution. The contralateral asymptomatic nerve in patients with classic trigeminal neuralgia had the same distribution of angles. The symptomatic nerves in patients with classic trigeminal neuralgia had a bimodal distribution; 83% of patients fell into the same distribution as the asymptomatic nerves, but the other 15% had an average angle of 143° (SD, 7°). This difference was statistically significant ( P < .0001)., Conclusions: Patients with the clinical syndrome of classic trigeminal neuralgia fell into 2 categories based on the radiologic measurement of the SATNaPT. Most patients had an anatomically normal nerve that was affected by vascular compression, but 17% of these patients had aberrant anatomy that may cause or contribute to their clinical presentation. Further study is needed to determine whether this subset of patients should receive a different surgery to better address their underlying anatomic abnormality. The SATNaPT measurement should be included in every MR imaging interpretation performed on patients with classic trigeminal neuralgia., (© 2022 by American Journal of Neuroradiology.)

Machine learning for hospital operations is under-studied. We present a prediction pipeline that uses live electronic health-records for patients in a UK teaching hospital's emergency department (ED) to generate short-term, probabilistic forecasts of emergency admissions. A set of XGBoost classifiers applied to 109,465 ED visits yielded AUROCs from 0.82 to 0.90 depending on elapsed visit-time at the point of prediction. Patient-level probabilities of admission were aggregated to forecast the number of admissions among current ED patients and, incorporating patients yet to arrive, total emergency admissions within specified time-windows. The pipeline gave a mean absolute error (MAE) of 4.0 admissions (mean percentage error of 17%) versus 6.5 (32%) for a benchmark metric. Models developed with 104,504 later visits during the Covid-19 pandemic gave AUROCs of 0.68-0.90 and MAE of 4.2 (30%) versus a 4.9 (33%) benchmark. We discuss how we surmounted challenges of designing and implementing models for real-time use, including temporal framing, data preparation, and changing operational conditions., (© 2022. The Author(s).)

Background: Predicting bed occupancy for hospitalised patients with COVID-19 requires understanding of length of stay (LoS) in particular bed types. LoS can vary depending on the patient's "bed pathway" - the sequence of transfers of individual patients between bed types during a hospital stay. In this study, we characterise these pathways, and their impact on predicted hospital bed occupancy., Methods: We obtained data from University College Hospital (UCH) and the ISARIC4C COVID-19 Clinical Information Network (CO-CIN) on hospitalised patients with COVID-19 who required care in general ward or critical care (CC) beds to determine possible bed pathways and LoS. We developed a discrete-time model to examine the implications of using either bed pathways or only average LoS by bed type to forecast bed occupancy. We compared model-predicted bed occupancy to publicly available bed occupancy data on COVID-19 in England between March and August 2020., Results: In both the UCH and CO-CIN datasets, 82% of hospitalised patients with COVID-19 only received care in general ward beds. We identified four other bed pathways, present in both datasets: "Ward, CC, Ward", "Ward, CC", "CC" and "CC, Ward". Mean LoS varied by bed type, pathway, and dataset, between 1.78 and 13.53 days. For UCH, we found that using bed pathways improved the accuracy of bed occupancy predictions, while only using an average LoS for each bed type underestimated true bed occupancy. However, using the CO-CIN LoS dataset we were not able to replicate past data on bed occupancy in England, suggesting regional LoS heterogeneities., Conclusions: We identified five bed pathways, with substantial variation in LoS by bed type, pathway, and geography. This might be caused by local differences in patient characteristics, clinical care strategies, or resource availability, and suggests that national LoS averages may not be appropriate for local forecasts of bed occupancy for COVID-19., Trial Registration: The ISARIC WHO CCP-UK study ISRCTN66726260 was retrospectively registered on 21/04/2020 and designated an Urgent Public Health Research Study by NIHR.

An effective model to calculate thermal conductivity of polymer composites using core-shell fillers is presented, wherein a core material of filler grains is covered by a layer of a high-thermal-conductivity (HTC) material. Such fillers can provide a significant increase of the composite thermal conductivity by an addition of a small amount of the HTC material. The model employs the Lewis-Nielsen formula describing filled systems. The effective thermal conductivity of the core-shell filler grains is calculated using the Russel model for porous materials. Modelling results are compared with recent measurements made on composites filled with cellulose microbeads coated with hexagonal boron nitride (h-BN) platelets and good agreement is demonstrated. Comparison with measurements made on epoxy composites, using silver-coated glass spheres as a filler, is also provided. It is demonstrated how the modelling procedure can improve understanding of properties of materials and structures used and mechanisms of thermal conduction within the composite.

Type I AV fistulas of the spinal cord are exceedingly rare. The average age at diagnosis is 50. Clinical presentation is often very non-specific, and sensory deficits and sphincter dysfunction may also occur. Neurological deterioration is generally gradual. Thus, failure to diagnosis frequently results in permanent disability. A 22-year-old female complained of a "muscle spasm" in the midline thoracic area with no history of trauma or prior occurrence. She also experienced bilateral lower extremity weakness/numbness and perianal anesthesia. She is a healthy female with no medical problems. Exam revealed lower extremity motor function of 1/5 as well as diminished sensation. A foley catheter was placed for urinary retention. The remainder of the neurological exam was normal. MRI demonstrated a lesion at the fourth thoracic level with significant cord compression. The patient was taken emergently to the operating room by neurosurgery. This case demonstrates a rare disorder occurring in a 22-year old female, far younger than the typical 50-year old patient. Moreover, the lesion was located in the thoracic rather than the typical lumbar cord. Symptoms may be misinterpreted as a peripheral nerve lesion and delay time to diagnosis. Early diagnosis remains critical to prevent permanent neurologic sequelae. AV fistula should remain high on the differential of patients presenting with back pain and focal neurologic complaints., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Suboccipital cough-induced headaches are considered a hallmark symptom of Chiari malformation type I (CMI). However, non--Valsalva-related suboccipital headaches and headaches in other locations are also common in CMI. The diagnostic significance and the underlying factors associated with these different headaches types are not well understood., Objective: To compare cranial morphology and hydrodynamics in 3 types of headaches in CMI to better understand the pathophysiological basis for the different headache characteristics., Methods: Twenty-two cranial physiological and morphological measures were obtained with specialized magnetic resonance imaging scans from 63 symptomatic pretreated CMI patients, 40 with suboccipital headaches induced by Valsalva maneuvers (34 women; age, 36 ± 10 years), 15 with non--Valsalva-related suboccipital headaches (10 women; age, 33 ± 9 years), 8 with nonsuboccipital non--Valsalva-induced headaches (8 women; age, 39 ± 13 years), and 37 control subjects (24 women; age, 36 ± 12 years). Group differences were identified with the use of the 2-tailed Student t test., Results: Posterior cranial fossa markers of CMI were similar among the 3 headache subtypes. However, the Valsalva-related suboccipital headaches cohort demonstrated a significantly lower intracranial compliance index than the non--Valsalva-related suboccipital headaches cohort (7.5 ± 3.4 vs 10.9 ± 4.9), lower intracranial volume change during the cardiac cycle (0.48 ± 0.19 vs 0.61 ± 0.16 mL), and higher magnetic resonance imaging--derived intracranial pressure (11.1 ± 4.3 vs 7.7 ± 2.8 mm Hg; P = .02). The Valsalva-related suboccipital headaches cohort had smaller intracranial and lateral ventricular volumes compared with the healthy cohort. The non--Valsalva-related suboccipital headaches cohort had reduced venous drainage through the jugular veins., Conclusion: Valsalva-induced worsening of occipital headaches appears to be related to a small intracranial volume rather than the smaller posterior cranial fossa. This explains the reduced intracranial compliance and corresponding higher pressure measured in CMI patients with headaches affected by Valsalva maneuvers.

Background and Purpose: A minority of patients who undergo microvascular decompression for hemifacial spasm do not improve after the first operation. We sought to determine the most common locations of unaddressed neurovascular contact in patients with persistent or recurrent hemifacial spasm despite prior microvascular decompression., Materials and Methods: Eighteen patients with a history of a microvascular decompression presented with persistent hemifacial spasm. All patients underwent thin-section steady-state free precession MR imaging. Fourteen patients underwent repeat microvascular decompression at our institution. Images were evaluated for the following: the presence of persistent vascular compression of the facial nerve, type of culprit vessel (artery or vein), name of the culprit artery, segment of the nerve in contact with the vessel, and location of the point of contact relative to the existing surgical pledget. The imaging findings were compared with the operative findings., Results: In 12 of the 18 patients (67%), persistent vascular compression was identified by imaging. In 11 of these 12 patients, the culprit vessel was an artery. Compression of the attached segment (along the ventral surface of the pons) was identified in most patients (58%, 7/12). The point of contact was proximal to the surgical pledget in most patients (83%, 10/12). The imaging interpretation was concordant with the surgical results regarding artery versus vein in 86% of cases and regarding the segment of the nerve contacted in 92%., Conclusions: In patients with persistent hemifacial spasm despite microvascular decompression, the unaddressed vascular compression is typically proximal to the previously placed pledget, usually along the attached segment of the nerve. Re-imaging with high-resolution T2-weighted MR imaging will usually identify the culprit vessel., (© 2015 by American Journal of Neuroradiology.)

Objective: Residual lateral spread response (LSR) after seemingly adequate decompression for hemifacial spasms (HFSs) can provide prognostic information about the outcome of microvascular decompression (MVD). In the present study, the main objective was to evaluate the clinical and prognostic impact of residual LSR after adequate MVD for HFS., Methods: An observational study was conducted in patients who underwent MVD for HFS at the University of Pittsburgh Medical Center between January 2000 and December 2007. Clinical and neurophysiological outcomes after pre- and post-MVD, including spasm relief, amplitude and latency of LSR, and postoperative complications were collected from groups with and without residual LSR after adequate decompression. Data analysis was performed to see the impact of residual LSR on HFS outcomes., Results: There was no significant difference in preoperative clinical characteristics as well as postoperative complications between the two groups. The patient had significantly higher spasm relief in immediate postoperative period (p = 0.01) and at discharge (p = 0.002) when LSR disappeared during the procedure. There is no difference in spasm relief at follow-up period between the two groups (p = 0.69)., Conclusion: Lateral spread is an invaluable tool in MVD for HFSs. Adequate decompression in patients with residual LSR improved long-term spasm relief. Constant communication between neurophysiologists and the surgeon might be vital to achieve adequate decompression. The amplitude of residual LSR after adequate decompression does not significantly affect the long-term spasm relief.

Background: It has been well documented that, along with tonsillar herniation, Chiari Malformation Type I (CMI) is associated with smaller posterior cranial fossa (PCF) and altered cerebrospinal fluid (CSF) flow and tissue motion in the craniocervical junction., Objective: This study assesses the relationship between PCF volumetry and CSF and tissue dynamics toward a combined imaging-based morphological-physiological characterization of CMI. Multivariate analysis is used to identify the subset of parameters that best discriminates CMI from a healthy cohort., Methods: Eleven length and volumetric measures of PCF, including crowdedness and 4th ventricle volume, 4 measures of CSF and cord motion in the craniocervical junction, and 5 global intracranial measures, including intracranial compliance and pressure, were measured by magnetic resonance imaging (MRI) in 36 symptomatic CMI subjects (28 female, 37 ± 11 years) and 37 control subjects (24 female, 36 ± 12 years). The CMI group was further divided based on symptomatology into "typical" and "atypical" subgroups., Results: Ten of the 20 morphologic and physiologic measures were significantly different between the CMI and the control cohorts. These parameters also had less variability and stronger significance in the typical CMI compared with the atypical. The measures with the most significance were clival and supraocciput lengths, PCF crowdedness, normalized PCF volume, 4th ventricle volume, maximal cord displacement (P < .001), and MR measure of intracranial pressure (P = .007). Multivariate testing identified cord displacement, PCF crowdedness, and normalized PCF as the strongest discriminator subset between CMI and controls. MR measure of intracranial pressure was higher in the typical CMI cohort compared with the atypical., Conclusion: The identified 10 complementing morphological and physiological measures provide a more complete and symptomatology-relevant characterization of CMI than tonsillar herniation alone.

Background: In an attempt to contain Medicaid pharmacy costs, nearly all states impose dispensing limits on medication days' supply. Although longer days' supply appears to increase the potential for medication wastage, previous studies suggest that it may also decrease pharmacy expenditures by reducing dispensing fees and drug ingredient costs. This study was conducted to determine whether 90-day refills at community pharmacies could improve adherence, minimize wastage, and control costs., Methods: This retrospective observational study used California Medicaid claims, from the Walgreens pharmacy chain dated January 2010, to identify 52,898 patients prescribed statin, antihypertensive, selective serotonin reuptake inhibitor (SSRI), or oral hypoglycemic medications. Adherence was measured by medication possession ratio (MPR) and persistency with a 30-day gap. Medication wastage was defined as a switch of drug or drug strength within the same therapeutic class that occurred before the expected refill date., Results: Adherence was 20% higher and persistency was 23% higher for the 90-day group than the 30-day group. This amounted to an average increase of 0.14 MPR and 44 days of continuous therapy. The two groups had comparable proportions of patients with wastage. After subtracting an average wastage cost of $7.34 per person per year (PPPY), all therapeutic classes had PPPY savings: statins ($7.70), antihypertensives ($10.80), SSRIs ($18.52), and oral hypoglycemics ($26.86)., Conclusion: Across four drug categories and compared to 30-day refills, patients with 90-day refills had greater medication adherence, greater persistency, nominal wastage, and greater savings.

Background: Supra orbital frontal minicraniotomy is one of the most commonly used minimally invasive approaches for anterior cranial fossa lesions., Objective: To describe our experience with the transpalpebral "eyelid" incision to obtain access to the anterior cranial fossa., Methods: We describe the approach and technique of the transpalpebral eyelid incision in a step-by-step fashion and discuss the results of 40 cases for which the eyelid incision was used. We retrospectively reviewed the charts of these patients to analyze outcomes with regard to opening and closing time, length of hospital stay, residual aneurysm or Simpson grade for resection, complications, and cosmetic result., Results: We treated 31 anterior circulation aneurysms (28 unruptured and 3 ruptured), 7 anterior skull base meningiomas, 1 frontal low-grade glioma, and 1 frontal cavernoma using the transpalpebral incision. Opening time was about 45 to 60 minutes, and closure time from dura to skin was about 45 to 60 minutes. The hospital length of stay was similar to that in our open craniotomy cases. No residual aneurysm was demonstrated in the follow-up studies of all 31 aneurysms. Simpson grade I resection was achieved in 6 meningiomas. Complications included 1 postoperative eyelid hematoma, 2 postoperative infections, and a subclinical stroke discovered on postoperative imaging. Excellent cosmetic outcome was accomplished in 39 of 40 patients., Conclusion: The transpalpebral approach provides dissection in natural anatomical planes, affords preservation of the frontalis muscle, avoids injury to nerve VII branches, and results in an excellent cosmetic outcome.

In this report, we present a 65-year-old man who presented with signs and symptoms consistent with impending brain herniation. Emergent imaging revealed a hyperdense mass in the suprasellar region. Urgent surgery was performed and final pathology eventuated a pilocytic astrocytoma. Although rare cases of suprasellar pilocytic astrocytoma in children and adults have been reported, we report an interesting case of a hemorrhagic suprasellar pilocytic astrocytoma in an elderly adult (without prior anticoagulant use) causing impending brain herniation secondary to obstructive hydrocephalus.

Electric arc furnace dust (EAFD) is a major issue for processing technologies: Several million tons per year are generated, it contains both valuable and hazardous metals and yet no available treatment process has proven to be superior to all others. Processes currently applied or being developed are either of hydro- or pyrometallurgical type, which are very costly. In the paper testing of some physical separation methods of electric arc furnace dust from Polish steel industry were investigated. SEM, EDX analyses as well as grain size observations of dust particles were additionally performed. All investigations confirmed a possibility of effective magnetic and mechanical separation of EAFD particles.

Object: The indications, operative findings, and outcomes of vestibular schwannoma microsurgery are controversial when it is performed after stereotactic radiosurgery. To address these issues, the authors reviewed the experience at two academic medical centers., Methods: During a 10-year interval, 452 patients with unilateral vestibular schwannomas underwent gamma knife radiosurgery. Thirteen patients (2.9%) underwent delayed microsurgery at a median of 27 months (range 7-72 months) after they had undergone radiosurgery. Six of the 13 patients had undergone one or more microsurgical procedures before they underwent radiosurgery. The indications for surgery were tumor enlargement with stable symptoms in five patients, tumor enlargement with new or increased symptoms in five patients, and increased symptoms without evidence of tumor growth in three patients. Gross-total resection was achieved in seven patients and near-gross-total resection in four patients. The surgery was described as more difficult than that typically performed for schwannoma in eight patients, no different in four patients, and easier in one patient. At the last follow-up evaluation, three patients had normal or near-normal facial function, three patients had moderate facial dysfunction, and seven had facial palsies. Three patients were incapable of caring for themselves, and one patient died of progression of a malignant triton tumor., Conclusions: Failed radiosurgery in cases of vestibular schwannoma was rare. No clear relationship was demonstrated between the use of radiosurgery and the subsequent ease or difficulty of delayed microsurgery. Because some patients have temporary enlargement of their tumor after radiosurgery, the need for surgical resection after radiosurgery should be reviewed with the neurosurgeon who performed the radiosurgery and should be delayed until sustained tumor growth is confirmed. A subtotal tumor resection should be considered for patients who require surgical resection of their tumor after vestibular schwannoma radiosurgery.