Genetic predisposition in patients with severe COVID-19.

The coronavirus disease 2019 (COVID-19) is a global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. COVID-19 has a variety of clinical manifestations, ranging from asymptomatic infection or mild symptoms to severe symptoms. Severe COVID-19 patients experience cytokine storm, resulting in multi-organ failure and even death. Male gender, old age, and pre-existing comorbidities (such as hypertension and diabetes ) are risk factors for COVID-19 severity. Recently, a series of studies suggested that genetic defects might also be related to disease severity and the cytokine storm occurence. Genetic variants in key viral immune genes, such as TLR7 and UNC13D, have been identified in severe COVID-19 patients from previous reports. In this review, we summarize the mechanisms underlying immune responses against SARS-CoV-2 and genetic variants that associated with the severity of COVID-19. The study of genetic basis of COVID-19 will be of great benefit for early disease detection and intervention.

High-performance asymmetric optical transmission based on coupled complementary subwavelength gratings.

Asymmetric transmission (AT) devices are fundamental elements for optical computing and information processing. We here propose an AT device consisting of a pair of coupled complementary subwavelength gratings. Different from previous works, asymmetric dielectric environment is employed for unidirectional excitation of surface plasmon polaritons (SPPs) and thus asymmetric optical transmission, and near-field coupling effect inherent in the coupled complementary structure is exploited to enhance forward transmission and AT behavior, and determine operation bandwidth as well. The influence of asymmetric dielectric environment, effect of vertical and lateral couplings, interactions of electric- and magnetic-dipole moments and the realization of Kerker conditions, are investigated in depth to unearth the AT mechanism and performance. High-performance AT with large forward transmittance of 0.96 and broad bandwidth of 174 nm is achieved at wavelength 1250 nm. Our work helps people to gain a better understanding of near-filed coupling effect in coupled complementary structures, expand their application fields, and it also offers an alternate way to high-performance AT devices.

Design and synthesis of substituted pyrido[3,2-d]-1,2,3-triazines as potential Pim-1 inhibitors.

A novel series of substituted pyrido[3,2-d]-1,2,3-triazines were designed and synthesized as Pim-1 inhibitors through scaffold hopping. Most of the derivatives showed potent in vitro Pim-1 inhibitory activities and anti-proliferative effects toward prostate cancer cells. Among them, 6b, 6h and 6m showed the best Pim-1 inhibitory activity with IC50 values of 0.69, 0.60 and 0.80 µM, respectively. Furthermore, compounds 6b, 6i, 6j and 6m showed strong inhibitory activity to human prostate cancer LNcap and PC-3 cell lines with IC50 values at low micromolar level. Structure-activity relationship analysis revealed that appropriate substitutions at C-6 positions contributed to the kinase inhibition and antiproliferative effects. Moreover, western blot assay suggested that 6j could decrease the levels of p-BAD and p-4E-BP1 in a dose-dependent manner in PC-3 cells. Docking studies showed that 3-N of the scaffold formed a hydrogen bond with Lys67, aromatic 4-aniline formed a key π-π stack with Phe49. Taken together, this study might provide the first sight for developing the pyrido[3,2-d]-1,2,3-triazine scaffold as novel Pim-1 inhibitors.