Unequal channel spacing 8×5 Gbps optical system utilizing different signal representations.

Data representations are important to communication networks; they convert the data bits into a signal form, which affects the system capacity, maximum bit rate, transmission distance, and different linear and nonlinear impairments. In this paper, we propose non-return-to-zero (NRZ), chirped NRZ, duobinary, and duobinary return-to-zero (DRZ) data representations with eight dense wavelength division multiplexing channels for transmitting a 5 Gbps data rate through a 250 km fiber length. The results of the simulation design are calculated at different equal and unequal channel spacings, and the quality factor is measured over a wide range of optical power. For equal channel spacing, the DRZ has a preferable performance with a 28.40 quality factor at 18 dBm threshold power, and the chirped NRZ has a preferable performance with a 26.06 quality factor at 12 dBm threshold power. For unequal channel spacing, the DRZ has a 25.76 quality factor at 17 dBm threshold power, and the NRZ has a 25.06 quality factor at 10 dBm threshold power.

Efficacy and safety of mRNA and AstraZeneca COVID-19 vaccines in patients with autoimmune rheumatic diseases: A systematic review.

BACKGROUND: Patients with autoimmune rheumatic diseases (ARD) are at a potentially higher risk for COVID-19 infection complications. Given their inherent altered immune system and the use of immunomodulatory medications, vaccine immunogenicity could be unpredictable with a suboptimal or even an exaggerated immunological response. The aim of this study is to provide real-time data on the emerging evidence of COVID-19 vaccines' efficacy and safety in patients with ARDs. METHODS: We performed a literature search of the PubMed, EMBASE, and OVID databases up to 11-13 April 2022 on the efficacy and safety of both types of the mRNA-vaccines and the AstraZeneca COVID-19 vaccines in patients with ARD. The risk of bias in the retrieved studies was evaluated using the Quality in Prognostic Studies tool. Also, current clinical practice guidelines from multiple international professional societies were reviewed. RESULTS: We identified 60 prognostic studies, 69 case reports and case series, and eight international clinical practice guidelines. Our results demonstrated that most patients with ARDs were able to mount humoral and/or cellular responses after two doses of COVID-19 vaccine although this response was suboptimal in patients receiving certain disease-modifying medications including rituximab, methotrexate, mycophenolate mofetil, daily glucocorticoids >10 mg, abatacept, as well as in older individuals, and those with comorbid interstitial lung diseases. Safety reports on COVID-19 vaccines in patients with ARDs were largely reassuring with mostly self-limiting adverse events and very minimal post-vaccination disease flares. CONCLUSION: Both types of the mRNA-vaccines and the AstraZeneca COVID-19 vaccines are highly effective and safe in patients with ARD. However, due to their suboptimal response in some patients, alternative mitigation strategies such as booster vaccines and shielding practices should also be followed. Management of immunomodulatory treatment regimens during the peri vaccination period should be individualized through shared decision making with patients and their attending rheumatologists.

New-onset severe eosinophilic granulomatosis with polyangiitis following the third dose of mRNA COVID-19 vaccine: A case report.

Eosinophilic granulomatosis with polyangiitis (EGPA) is a complex multifactorial disease that results in multisystemic inflammation of the small- and medium-sized arteries. The exact pathogenesis of this syndrome is poorly understood, but it is postulated to result from a combination of eosinophilic dysfunction, genetic predisposition, and the development of autoantibodies after exposure to an unknown stimulus. We describe a case of new-onset EGPA following the third dose of the Pfizer-BioNTech mRNA vaccine in an infection-naive middle-aged man with a background history of allergic respiratory symptoms. The patient developed acute onset of mononeuritis multiplex, pauci-immune glomerulonephritis, and leucocytoclastic vasculitis 10 days after receiving the booster dose. His laboratory markers including eosinophil count, antineutrophil cytoplasmic antibodies, and renal function tests improved markedly after the initiation of pulse steroid therapy and rituximab infusion. However, his peripheral muscle weakness and neuropathic pain did not respond to the initial therapy but improved later with intravenous cyclophosphamide and intravenous immunoglobulin. To the best of our knowledge, this is the fourth case report of post-coronavirus disease 2019 vaccination precipitation of EGPA. All reported cases including our report were in patients with previous allergic manifestations who received mRNA-based coronavirus disease 2019 vaccines, and all the patients developed mononeuritis multiplex at presentation. Despite the few reported cases of post-vaccination autoimmune phenomena, the temporal association between vaccination administration and disease onset does not indicate causality, given the mass vaccination programmes employed. However, the novel use of the mRNA platform in vaccine delivery necessitates vigilant monitoring by the scientific committee.

An unusual presentation of invasive aspergillosis with submandibular swelling in a 49-year-old man with end-stage renal disease: A case report.

Invasive aspergillosis (IA) is a fatal disease and is related to immunocompromised patients like HIV, solid organ/allogeneic stem cell transplant patients, patients on immunosuppressive therapy or chemotherapy agents, burn patients and malnourished patients. Diagnosis is challenging due to the non-specific nature of symptoms. Usually, the patient presents with fever and respiratory symptoms such as cough and haemoptysis. We present a case of IA in a 49-year-old man with end-stage renal disease who presented with fever and developed a submandibular swelling. Further imaging studies supported the possibility of having underlying IA and accordingly he was promptly treated with systemic antifungal therapy with good response. As per our knowledge, IA presenting as submandibular swelling has not been reported in the literature. Our main aim is to highlight the significance of early diagnosis and management in such a rare presentation associated with a life-threatening condition like IA.

A Case Report of Statin-Induced Immune-Mediated Necrotizing Myopathy Treatment Challenges.

Statin-induced necrotizing autoimmune myopathy is an immune-mediated necrotizing myopathy related to the use of statins. It is a very rare disease, which usually presents with proximal muscle weakness and frank elevation in creatine kinase levels. Stopping statin and the use of immunosuppressive therapy are considered the mainstay therapy. Use of steroids in patients with inflammatory myopathy can be complicated by steroid-induced myopathy. Herein, we present a case of a 55-year-old patient with statin-induced necrotizing autoimmune myopathy based on the presence of proximal muscle weakness, magnetic resonance findings, suggestive muscle biopsy features, and positive anti-HMGCR autoantibodies. The patient was treated with triple immunosuppressive therapy with a particularly good response to intravenous immunoglobulin. This report highlights the importance of timely diagnosis and early use of combined immunosuppressive therapy to improve patients' outcome affected by this rare disease.