Enhanced Mechanical Properties and Microstructure of Accumulative Roll-Bonded Co/Pb Nanocomposite.

Lead composites have been used as anodes in the electrowinning process to produce metals such as copper and zinc. Manufacturing stable lead anodes with appropriate mechanical and chemical properties is required to improve the performance of the electrowinning process. In this study, an accumulative roll bonding (ARB) method was used to fabricate a Co/Pb nanocomposite. Utilizing the ARB method can help us to achieve a uniform structure with enhanced mechanical properties via severe plastic deformation. The results showed that suitable tensile properties were obtained in Pb-0.5%Co-10pass samples. The tensile strength and strain of these samples were 2.51 times higher and 83.7% lower than that of as-cast pure Pb. They also showed creep resistance and hardness up to 1.8 and 2.5 times more than that of as-cast pure Pb. The ARB technique uniformly distributed Co particles in the Pb matrix. The enhanced strength of Pb samples was observed in the composite including grain sizes of less than 50 nm as a result of hindering the recovery phenomenon. The particle size of the Co distributed in the Pb matrix was 353 ± 259 nm. Compared to conventional methods, the ARB process improved the mechanical properties of Co/Pb composites and can open a new horizon to fabricating this composite in metal industries.

Age-Dependent Clinical Features and Prognosis of COVID-19 Patients.

Background: The clinical and paraclinical symptoms of COVID-19 differ across age groups. This study investigated the differences between these parameters and their outcomes in young, middle-aged, and elderly patients admitted to a COVID-19 referral center. Materials and Methods: This retrospective study encompassed patients with COVID-19 hospitalized at Khorshid Hospital (Isfahan, Iran) during February 23 to April 30, 2020. The patients' predisposing conditions, clinical and paraclinical findings, and outcomes were compared among three young, middle-aged, and elderly groups. Results: Of the 1185 hospitalized patients with suspected COVID-19, 1065 were discharged or died at the end of the study. Among these 1065 patients, 654 patients with the mean age of 57.7 years had positive PCR results or typical CT scans and were included in the study, of whom 77 (11.8%), 353 (54%), and 234 (34.2%) patients were assigned into the young, middle-aged, and elderly groups, respectively. There was no statistically significant difference among the three groups regarding the prevalence of clinical symptoms. Moreover, CRP, ESR, WBC, BUN, Cr, and lymphocytes were higher in the elderly group. The ground-glass opacity (GGO) (24.1%), GGO-consolidation (27.4%), and consolidation (10.3%) were the most common CT scan findings in the young, middle-aged, and elderly groups, respectively. Fifty-three patients (8.1%) died, and the mortality rates were 10.36%, 7.27%, and 3.8% in the elderly, middle-aged, and young groups, respectively. Conclusion: COVID 19 symptoms do not depend on age; however, paraclinical findings differ across young, middle-aged, and elderly patients.

A Rare Axonal Variant of Guillain-Barré Syndrome as a Neurological Complication of COVID-19 Infection.

Guillain-Barré syndrome (GBS) is a neurological disorder accompanied by several neurological signs and symptoms including progressive weakness and diminished or decreased reflexes. GBS was reported as one of the several neurological complications in MERS-CoV and SARS-CoV outbreaks. Several studies have reported GBS as a neurological complication in recent COVID-19 outbreak. We report on the case of a 55-years -old female who was hospitalized with dyspnea, dry cough, and myalgia. She developed Acute Motor & Sensory Axonal Neuropathy (AMSAN), a rare variant of GBS signs and symptoms including decreased muscle strength and pinprick sensation in both lower extremities during her hospitalization.

Short communication: investigating the effect of saffron (Crocus sativus L.) nano-sizing on its colour extraction efficiency: a preliminary study.

This study investigated the effect of saffron nano-sizing on its the colour extraction yield. The whole stigma was ball-milled at three different times (10, 20 and 100 h), immediately or with a 24 h delay was submitted to absorption test, and then the colour extraction efficiency was determined. When stigma was milled for 100 h, its particle size was reduced to less than 20 nm, as shown by SEM and TEM images, and its extraction efficiency was considerably increased by 19.8% as compared with the stigma blended for 10 min. However with a 24 h delay between the end of milling and absorption test, the yield of colour extraction significantly decreased. The recommended milling conditions resulting in extraction efficiency of 16.2% (in comparison with stigma blended for 10 min) were determined to be the milling for 10 h with initial tendering prior to milling operation.