Empirical model for quasi direct current interruption with a convoluted arc

This contribution considers various aspects of a quasi direct current, convoluted arc produced by a magnetic field (B-field) connected in parallel with an RLC circuit that have not been considered in combination. These aspects are the arc current limitation due to the arc convolution, changes in arc resistance due to the B-field and material ablation, and the relative significance of the RLC circuit in producing an artificial current zero. As a result, it has been possible to produce an empirical equation for predicting the current interruption capability in terms of the B-field magnitude and RLC components

Single left coronary artery with origin of right coronary artery from left circumflex: a case report

which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background: A 40-years-old female presented with intermittent chest pain and dyspnea on exertion. Case Presentation: Electrocardiography showed sinus rhythm with ST-depression in inferior and lateral leads. Subsequent exercise treadmill testing revealed significant ST-depression in V4–V5 and V6 leads. Coronary angiography later showed a single left coronary artery with right coronary artery arising from left circumflex artery, a rare anomaly of coronary arteries. No atheromatous lesion was seen during angiography. Conclusion: The dignosis of this anomaly is importsnt because the symptoms cannot be differentiated from atherosclerotic coronary artery disease. Case presentation A 40-years-old female was admitted to the hospital with intermittent substernal chest pain and dyspnea. She visited our outpatient clinic because of exacerbation o

Severe Primary Hyperparathyroidism Caused by Parathyroid Carcinoma in a 13‐Year‐Old Child; Novel Findings From HRpQCT

Primary hyperparathyroidism is a condition that occurs infrequently in children. Parathyroid carcinoma, as the underlying cause of hyperparathyroidism in this age group, is extraordinarily rare, with only a few cases reported in the literature. We present a 13-year-old boy with musculoskeletal pain who was found to have brown tumors from primary hyperparathyroidism caused by parafibromin-immunodeficient parathyroid carcinoma. Our patient had no clinical, biochemical, or radiographic evidence of pituitary adenomas, pancreatic tumors, thyroid tumors, pheochromocytoma, jaw tumors, renal abnormalities, or testicular lesions. Germline testing for AP2S1, CASR, CDC73/HRPT2, CDKN1B, GNA11, MEN1, PTH1R, RET, and the GCM2 gene showed no pathological variants, and a microarray of CDC73/HRPT2 did not reveal deletion or duplication. He was managed with i.v. fluids, calcitonin, pamidronate, and denosumab prior to surgery to stabilize hypercalcemia. After removal of a single parathyroid tumor, he developed severe hungry bone syndrome and required 3 weeks of continuous i.v. calcium infusion, in addition to oral calcium and activated vitamin D. Histopathological examination identified an angioinvasive parathyroid carcinoma with global loss of parafibromin (protein encoded by CDC73/HRPT2).HRpQCT and DXA studies were obtained prior to surgery and 18-months postsurgery. HRpQCT showed a resolution of osteolytic lesions combined with structural improvement of cortical porosity and an increase in both cortical thickness and density compared with levels prior to treatment. These findings highlight the added value of HRpQCT in primary hyperparathyroidism. In addition to our case, we have provided a review of the published cases of parathyroid cancer in children

Characterisation of the treatment provided for children with unilateral hearing loss

Background: Children with permanent unilateral hearing loss (UHL) are an understudied population, with limited data to inform the guidelines on clinical management. There is a funding gap in healthcare provision for the children with UHL in the United Kingdom, where genetic screening, support services, and devices are not consistently provided or fully funded in all areas. They are a disparate population with regard to aetiology and their degree of hearing loss, and hence their device choice and use. Despite having one “good ear”, some children with UHL can have similar outcomes, socially, behaviourally, and academically, to children with bilateral hearing loss, highlighting the importance of understanding this population. In this longitudinal cohort study, we aimed to characterise the management of the children with UHL and the gaps in the support services that are provided for the children in Nottingham, United Kingdom. Methods: A cohort study was conducted collecting longitudinal data over 17 years (2002–2019) for 63 children with permanent congenital confirmed UHL in a large tertiary regional referral centre for hearing loss in Nottingham, United Kingdom. The cases of UHL include permanent congenital, conductive, mixed, or sensorineural hearing loss, and the degree of hearing loss ranges from mild to profound. The data were taken from their diagnostic auditory brainstem responses and their two most recent hearing assessments. Descriptors were recorded of the devices trialled and used and the diagnoses including aetiology of UHL, age of first fit, degree of hearing loss, when and which type of device was used, why a device was not used, the support services provided, concerns raised, and who raised them. Results: Most children (45/63; 71%) trialled a device, and the remaining 18 children had no device trial on record. Most children (20/45; 44%) trialled a bone-conduction device, followed by contralateral routing of signal aid (15/45; 33%) and conventional hearing aids (9/45; 20%). Most children (36/45; 80%) who had a device indicated that they wore their device “all day” or every day in school. Few children (8/45; 18%) reported that they wore their device rarely, and the reasons for this included bullying (3/8), feedback from the device (2/8), and discomfort from the device (2/8). Only one child reported that the device was not helping with their hearing. The age that the children were first fitted with their hearing device varied a median of 2.5 years for hearing aids and bone-conduction devices and 7 years for a contralateral routing of signal aid. The length of time that the children had the device also varied widely (median of 26 months, range 3–135 months); the children had their bone-conduction hearing aid for the longest period of time (median of 32.5 months). There was a significant trend where more recent device fittings were happening for children at a younger age. Fifty-one children were referred by the paediatric audiologist to a support service, 72.5% (37/51) were subsequently followed up by the referred service with no issue, whilst the remaining 27.5% (14/51) encountered an issue leading to an unsuccessful provision of support. Overall, most children (65%, 41/63) had no reported concerns, and 28.5% (18/63) of the children went on to have a documented concern at some point during their audiological care: five with hearing aid difficulties, five with speech issues, four with no improvement in hearing, three facing self-image or bullying issues, and one case of a child struggling to interact socially with friends. Three of these children had not trialled a device. We documented every concern reported from the parents, clinicians, teachers of the deaf, and from the children themselves. Where concerns were raised, more than half (58.6%, 10/18) were by schools and teachers, the remaining four concerns were raised by the family, and further four concerns were raised by the children themselves. Conclusion: To discover what management will most benefit which children with permanent UHL, we first must characterise their treatment, their concerns, and the support services available for them. Despite the children with UHL being a highly disparate population—in terms of their aetiology, their device use, the degree of hearing loss, and the age at which they trial a device—the majority report they use their device mostly in school. In lieu of available data and in consideration of the devices that are available to them, it could be useful to support families and clinicians in understanding the devices which are most used and where they are used. Considering the reasons for cessation of regular device use counselling and support services would be vital to support the children with UHL

Increased RPA1 gene dosage affects genomic stability potentially contributing to 17p13.3 duplication syndrome

A novel microduplication syndrome involving various-sized contiguous duplications in 17p13.3 has recently been described, suggesting that increased copy number of genes in 17p13.3, particularly PAFAH1B1, is associated with clinical features including facial dysmorphism, developmental delay, and autism spectrum disorder. We have previously shown that patient-derived cell lines from individuals with haploinsufficiency of RPA1, a gene within 17p13.3, exhibit an impaired ATR-dependent DNA damage response (DDR). Here, we show that cell lines from patients with duplications specifically incorporating RPA1 exhibit a different although characteristic spectrum of DDR defects including abnormal S phase distribution, attenuated DNA double strand break (DSB)-induced RAD51 chromatin retention, elevated genomic instability, and increased sensitivity to DNA damaging agents. Using controlled conditional over-expression of RPA1 in a human model cell system, we also see attenuated DSB-induced RAD51 chromatin retention. Furthermore, we find that transient over-expression of RPA1 can impact on homologous recombination (HR) pathways following DSB formation, favouring engagement in aberrant forms of recombination and repair. Our data identifies unanticipated defects in the DDR associated with duplications in 17p13.3 in humans involving modest RPA1 over-expression

Efeitos de dietas com dois níveis de leucaena leucocephala (lam.) de Wit com e sem adição de Saccharomyces cerevisiae sobre a emissão do gás metano em bovinos.

O trabalho teve como objetivo avaliar o uso de leucena e seu efeito sobre a emissão de metano ruminal em dietas controladas contendo dois níveis dietéticos na presença ou ausência de levedura (Saccharomyces cerevisiae). Foram utilizados quatro bovinos mestiços com fístulas de rúmen, mantidos em baias individuais, submetidos aos seguintes tratamentos em Quadrado Latino 4x4: 20S = 80% de feno de gramínea + 20% de feno de leucena + zero de levedura; 50S = 50% de feno de gramínea + 50% de feno de leucena sem levedura; 20L = 80% feno de gramínea + 20% de feno de leucena + 10 g de levedura adicionada no rúmen; 50L = 50% feno de graminea + 50% de feno de leucena + 10 g de levedura. Foram determinadas a curva de pH do líquido ruminai e produção de gás metano coletado através da técnica do gás traçador interno SF6. Os valores médios de pH variaram de 6,72 a 6,96, sendo que o tratamento 50S foi o que manteve os maiores e mais estáveis pH, houve efeito significativo (PO,05) para níveis de leucena na ausência de levedura. O tratamento 50L promoveu redução na emissão de metano em g/kg MSI de 17,5% em relação ao uso de 20% de leucena com levedura e também diminuição nos valores médios absolutos de 12,3% e 10,5% comparados com dietas contendo 50% e 20% de leucena sem levedura, respectivamente, demonstrando haver um efeito associativo da leucena no nível mais alto na dieta com a presença de levedura no rúmen sobre a redução na produção de metano no rúmen de bovinos

A Systematic Literature Review of Students as Partners in Higher Education

“Students as Partners” (SaP) in higher education re-envisions students and staff as active collaborators in teaching and learning. Understanding what research on partnership communicates across the literature is timely and relevant as more staff and students come to embrace SaP. Through a systematic literature review of empirical research, we explored the question: How are SaP practices in higher education presented in the academic literature? Trends across results provide insights into four themes: the importance of reciprocity in partnership; the need to make space in the literature for sharing the (equal) realities of partnership; a focus on partnership activities that are small scale, at the undergraduate level, extracurricular, and focused on teaching and learning enhancement; and the need to move toward inclusive, partnered learning communities in higher education. We highlight nine implications for future research and practice.</jats:p

Impact of the Coronavirus Disease 2019 pandemic on neoadjuvant chemotherapy use in patients diagnosed with epithelial type ovarian cancer

IntroductionThe Coronavirus Disease 2019 (COVID-19) pandemic posed critical challenges in providing care to ovarian cancer (OC) patients, including delays in OC diagnosis and treatment initiation. To accommodate for delays in OC surgery, the Society of Gynecologic Oncology (SGO) recommended preferential use of neoadjuvant chemotherapy during the pandemic. The purpose of this study was to assess the association of the COVID-19 pandemic with neoadjuvant chemotherapy use in patients diagnosed with OC.MethodsThis retrospective cohort study included patients diagnosed with stage II-IV ovarian cancer of epithelial subtype between 01/01/2017-06/30/2021 at Kaiser Permanente Southern California (KPSC), a large integrated healthcare system in the United States. Ovarian cancer patients diagnosed between 2017-2020 were identified from KPSC’s Surveillance, Epidemiology, and End Results (SEER)-affiliated cancer registry. Patients diagnosed in 2021 were identified from the electronic medical records (EMR) using ICD-10 diagnosis codes, followed by medical chart review to validate diagnosis and extract information on histology and stage at diagnosis. March 4, 2020 was used as the cut-off to define pre-pandemic and pandemic periods. Patients diagnosed with COVID-19 between OC diagnosis and treatment completion were excluded. Data on neoadjuvant chemotherapy use were extracted from the cancer registry and EMR, supplemented by chart review. Modified Poisson regression was used to evaluate the association of the pandemic with neoadjuvant chemotherapy use.ResultsOf 566 OC patients, 160 (28.3%) were diagnosed in the pandemic period. Patients diagnosed in the pandemic period were slightly younger (mean age 62.7 vs 64.9 years, p=0.07) and had a higher burden of Charlson comorbidities (p=0.05) than patients diagnosed in pre-pandemic period. No differences in time to treatment initiation were observed by pandemic periods. Neoadjuvant chemotherapy use was documented in 58.7% patients during the pandemic period compared to 47.3% in pre-pandemic period (p=0.01). After adjusting for covariates, patients diagnosed in the pandemic period were 29% more likely to receive neoadjuvant chemotherapy than patients diagnosed in pre-pandemic period [RR(95%CI): 1.29(1.12-1.49)].DiscussionsOvarian cancer patients diagnosed in the COVID-19 pandemic were more likely to receive neoadjuvant chemotherapy than patients diagnosed before the pandemic. Future research on patient outcomes and trends in the post-pandemic period are warranted