A ring-shaped helicase unwinds DNA during chromosome replication in all organisms. Replicative helicases generally unwind duplex DNA an order of magnitude slower compared to their in vivo replication fork rates. However, the origin of slow DNA unwinding rates by replicative helicases and the mechanism by which other replication components increase helicase speed are unclear. Here, we demonstrate that engagement of the eukaryotic CMG helicase with template DNA at the replication fork impairs its helicase activity, which is alleviated by binding of the single-stranded DNA binding protein, RPA, to the excluded DNA strand. Intriguingly, we found that, when stalled due to interaction with the parental duplex, DNA rezipping-induced helicase backtracking reestablishes productive helicase-fork engagement, underscoring the significance of plasticity in helicase action. Our work provides a mechanistic basis for relatively slow duplex unwinding by replicative helicases and explains how replisome components that interact with the excluded DNA strand stimulate fork rates.Long-term follow up studies from Ebola virus disease (EVD) survivors (EBOV_S) are lacking. Here, we evaluate immune and gene expression profiles in 35 Guinean EBOV_S from the last West African outbreak, a median of 23 months (IQR [18-25]) after discharge from treatment center. Compared with healthy donors, EBOV_S exhibit increases of blood markers of inflammation, intestinal tissue damage, T cell and B cell activation and a depletion of circulating dendritic cells. All survivors have EBOV-specific IgG antibodies and robust and polyfunctional EBOV-specific memory T-cell responses. Deep sequencing of the genes expressed in blood reveals an enrichment in 'inflammation' and 'antiviral' pathways. Integrated analyses identify specific immune markers associated with the persistence of clinical symptoms. This study identifies a set of biological and genetic markers that could be used to define a signature of "chronic Ebola virus disease (CEVD)".BACKGROUND Tattoos are popular in modern times. Selleck CC-930 Due to the occurance of adverse effects such as poor aesthetic value, scar hyperplasia, and abnormal pigments, there is a high demand for uniform operation standards as well as standards for tattoo technologies. In the present study we used Sprague-Dawley rats to assess the tattoo removal efficacy of use of a picosecond laser at various energy values. MATERIAL AND METHODS Tattoos were made on the backs of rats, then we used a picosecond laser set at various energy parameters to remove the tattoos. After performing the removal procedure in multiple groups, we selected the most suitable energy levels with corresponding parameters for the tattoo removal. We recruited human volunteers who wanted their tattoos removed and used the energy level found to perform best during tattoo removal experiments. The tattoo removal effects were evaluated and verified. Four tattoo volunteers were treated by using the optimal energy parameters for picosecond laser technology. RESULTS Through characterization observation and pathological staining results, it was demonstrated that the 1.9 mJ/μbeam energy laser had the best hollowing effect and the most complete pigment particle crushing effect in the rat skin, and had the best tattoo removal effect. CONCLUSIONS We leveraged the evaluation standard to choose the most suitable energy value of the picosecond laser, which had a good tattoo removal effect and could be employed as a reference for clinical removal of tattoos. This process provides criteria for tattoo removal evaluations as well as alternatives for tattoo removal in clinical practice.BACKGROUND Coronavirus disease 2019 (COVID-19) continues to spread, with confirmed cases now in more than 200 countries. Thus far there are no proven therapeutic options to treat COVID-19. We report a case of COVID-19 with acute respiratory distress syndrome who was treated with high-dose vitamin C infusion and was the first case to have early recovery from the disease at our institute. CASE REPORT A 74-year-old woman with no recent sick contacts or travel history presented with fever, cough, and shortness of breath. Her vital signs were normal except for oxygen saturation of 87% and bilateral rhonchi on lung auscultation. Chest radiography revealed air space opacity in the right upper lobe, suspicious for pneumonia. A nasopharyngeal swab for severe acute respiratory syndrome coronavirus-2 came back positive while the patient was in the airborne-isolation unit. Laboratory data showed lymphopenia and elevated lactate dehydrogenase, ferritin, and interleukin-6. The patient was initially started on oral hydroxychloroquine and azithromycin. On day 6, she developed ARDS and septic shock, for which mechanical ventilation and pressor support were started, along with infusion of high-dose intravenous vitamin C. The patient improved clinically and was able to be taken off mechanical ventilation within 5 days. CONCLUSIONS This report highlights the potential benefits of high-dose intravenous vitamin C in critically ill COVID-19 patients in terms of rapid recovery and shortened length of mechanical ventilation and ICU stay. Further studies will elaborate on the efficacy of intravenous vitamin C in critically ill COVID-19.We report a case of intraconal grease gun injury along with traumatic optic neuropathy in a 20-year-old male. He presented with dimness of vision and proptosis of the left eye (LE) following an accidental injury at work place. The computer tomography of orbit revealed hypodense grease orbit. Cream colored grease was continually exuding from the conjunctival wound. Patient improved rapidly after the surgical removal of the grease by anterior orbitotomy. Grease gun injuries to the orbit have rarely been reported. The present case is the eighth report throughout the world, and the first in India as per our knowledge.We report a new observation of conjunctival intraepithelial neoplasia (CIN) in a young man following years of electronic cigarette use. A 22-year-old man with a 5-year electronic cigarette use (vaping) developed painless unilateral blurred vision in the right eye from mild superficial corneal opacification, unresponsive to topical antiviral therapy. Corneal scraping documented no infectious etiology. The abnormality persisted for 1 year and superficial keratectomy revealed high-grade CIN with enlarged pleomorphic and dyskeratotic cells. Interferon-alpha-2b was instituted. In this case, chronic exposure to electronic cigarette vapors (vaping) could have been associated with CIN in this young patient.