The Characteristics of Ocular Findings and the Presence of SARS-CoV-2 in the Tears of Coronavirus Disease 2019 Patients.

Purpose The purpose of the study is to observe the characteristics of ocular manifestations in coronavirus disease 2019 (COVID-19) patients and to analyze the presence of severe acute respiratory syndrome coronavirus 2 ribonucleic acid (SARS-CoV-2 RNA) in the tears of patients with moderate-to-severe COVID-19. Material and methods We conducted this prospective cross-sectional study from February to June 2021 at the All India Institute of Medical Sciences, one of the tertiary eye care centers in Nagpur, India. The study included confirmed COVID-19 patients based on real-time reverse transcription-polymerase chain reaction (RT-PCR) nasopharyngeal swabs, whether or not the patients exhibited ocular symptoms. We recorded detailed information regarding the patients' history, including demographic profile, ocular symptoms, systemic symptoms, and radiologic findings. We collected ocular samples within 48 hours of collecting naso-oropharyngeal samples from the patients' eyes. We used conjunctival swabs to obtain tear samples, which we then placed in viral transport media (VTM) for cold chain transportation to the microbiology department. We performed RT-PCR on the tear samples to detect the presence of the SARS-CoV-2 virus. Result We included 40 patients in the study, with 26 (65%) classified as having moderate COVID-19, six (15%) classified as having severe COVID-19, and the remaining having mild COVID-19. Out of the 40 patients, five (12%) tested positive for SARS-CoV-2 in the tear sample using RT-PCR, seven (17%) exhibited ocular signs and symptoms, and only one tested positive for SARS-CoV-2 in their tears. The ocular manifestations observed in COVID-19 patients included dry eye, conjunctivitis (including conjunctival hyperemia and epiphora), and lid edema. Notably, we detected a positive COVID-19 tear sample in patients both with and without ocular symptoms. Conclusion Limited reports have focused on ocular involvement in patients with COVID-19. However, our study demonstrates the detection of SARS-CoV-2 in conjunctival swabs from confirmed COVID-19 patients, albeit with a lower positivity rate. Despite the low prevalence of the virus found in tears, there is a potential risk of transmission through ocular routes. It is noteworthy that we observed a COVID-19-positive tear sample in patients with and without ocular symptoms. Therefore, it is important to consider the possibility of ocular transmission even in the absence of ocular manifestations. Medical personnel should take careful precautions during ocular examinations of patients diagnosed with COVID-19 to minimize the risk of transmission.

Unilateral Lens Coloboma With Congenital Cataract: A Case Report From Central India.

A ten-year-old male child was referred with complaints of blurring of vision and deviation of the eye. On examination, the right eye has an esodeviation squint with a best corrected visual acuity of 6/60 Snellen's acuity and 6/6 Snellen's acuity in the left eye. Slit-lamp biomicroscope of the right eye showed coloboma at the 9 o'clock position with cataract. The rest of the anterior and posterior segments was normal in both eyes. Thus, a diagnosis of unilateral lens coloboma with amblyopia was made.

A comprehensive review on modulation of SIRT1 signaling pathways in the immune system of COVID-19 patients by phytotherapeutic melatonin and epigallocatechin-3-gallate.

SARS-CoV-2 infection has now become the world's most significant health hazard, with the World Health Organization declaring a pandemic on March 11, 2020. COVID-19 enters the lungs through angiotensin-converting enzyme 2 (ACE2) receptors, alters various signaling pathways, and causes immune cells to overproduce cytokines, resulting in mucosal inflammation, lung damage, and multiple organ failure in COVID-19 patients. Although several antiviral medications have been effective in managing the virus, they have not been effective in lowering the inflammation and symptoms of the illness. Several studies have found that epigallocatechin-3-gallate and melatonin upregulate sirtuins proteins, which leads to downregulation of pro-inflammatory gene transcription and NF-κB, protecting organisms from oxidative stress in autoimmune, respiratory, and cardiovascular illnesses. As a result, the purpose of this research is to understand more about the molecular pathways through which these phytochemicals affect COVID-19 patients' impaired immune systems, perhaps reducing hyperinflammation and symptom severity. PRACTICAL APPLICATIONS: Polyphenols are natural secondary metabolites that are found to be present in plants. EGCG a polyphenol belonging to the flavonoid family in tea has potent anti-inflammatory and antioxidative properties that helps to counter the inflammation and oxidative stress associated with many neurodegenerative diseases. Melatonin, another strong antioxidant in plants, has been shown to possess antiviral function and alleviate oxidative stress in many inflammatory diseases. In this review, we propose an alternative therapy for COVID-19 patients by supplementing their diet with these nutraceuticals that perhaps by modulating sirtuin signaling pathways counteract cytokine storm and oxidative stress, the root causes of severe inflammation and symptoms in these patients.

Negative voltage modulated multi-level resistive switching by using a Cr/BaTiOx/TiN structure and quantum conductance through evidence of H2O2 sensing mechanism.

Negative voltage modulated multi-level resistive switching with quantum conductance during staircase-type RESET and its transport characteristics in Cr/BaTiOx/TiN structure have been investigated for the first time. The as-deposited amorphous BaTiOx film has been confirmed by high-resolution transmission electron microscopy. X-ray photo-electron spectroscopy shows different oxidation states of Ba in the switching material, which is responsible for tunable more than 10 resistance states by varying negative stop voltage owing to slow decay value of RESET slope (217.39 mV/decade). Quantum conductance phenomenon has been observed in staircase RESET cycle of the memory devices. By inspecting the oxidation states of Ba+ and Ba2+ through measuring H2O2 with a low concentration of 1 nM in electrolyte/BaTiOx/SiO2/p-Si structure, the switching mechanism of each HRS level as well as the multi-level phenomenon has been explained by gradual dissolution of oxygen vacancy filament. Along with negative stop voltage modulated multi-level, current compliance dependent multi-level has also been demonstrated and resistance ratio up to 2000 has been achieved even for a thin (<5 nm) switching material. By considering oxidation-reduction of the conducting filaments, the current-voltage switching curve has been simulated as well. Hence, multi-level resistive switching of Cr/BaTiOx/TiN structure implies the promising applications in high dense, multistate non-volatile memories in near future.

Detection of pH and Enzyme-Free H2O2 Sensing Mechanism by Using GdO x Membrane in Electrolyte-Insulator-Semiconductor Structure.

A 15-nm-thick GdO x membrane in an electrolyte-insulator-semiconductor (EIS) structure shows a higher pH sensitivity of 54.2 mV/pH and enzyme-free hydrogen peroxide (H2O2) detection than those of the bare SiO2 and 3-nm-thick GdO x membranes for the first time. Polycrystalline grain and higher Gd content of the thicker GdO x films are confirmed by transmission electron microscopy (TEM) and X-ray photo-electron spectroscopy (XPS), respectively. In a thicker GdO x membrane, polycrystalline grain has lower energy gap and Gd(2+) oxidation states lead to change Gd(3+) states in the presence of H2O2, which are confirmed by electron energy loss spectroscopy (EELS). The oxidation/reduction (redox) properties of thicker GdO x membrane with higher Gd content are responsible for detecting H2O2 whereas both bare SiO2 and thinner GdO x membranes do not show sensing. A low detection limit of 1 µM is obtained due to strong catalytic activity of Gd. The reference voltage shift increases with increase of the H2O2 concentration from 1 to 200 µM owing to more generation of Gd(3+) ions, and the H2O2 sensing mechanism has been explained as well.