High attack rate of COVID-19 in an organized tour group of vaccinated travellers to Iceland.

In a COVID-19 outbreak in a group of 25 twice-vaccinated Israeli travellers, the attack rate was 84%, despite negative preflight polymerase chain reaction tests. This extremely high breakthrough infection rate is attributed mainly to close and prolonged exposures during long bus drives. Masking, distancing and personal responsibility are required to avoid such outbreaks.

Human iPSC-derived astrocytes from ALS patients with mutated C9ORF72 show increased oxidative stress and neurotoxicity.

Background: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that affects motor neurons (MNs). It was shown that human astrocytes with mutations in genes associated with ALS, like C9orf72 (C9) or SOD1, reduce survival of MNs. Astrocyte toxicity may be related to their dysfunction or the release of neurotoxic factors.

ALS-related human cortical and motor neurons survival is differentially affected by Sema3A.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by cell death of upper and lower motor neurons (MNs). The cause of MN cell loss is not completely understood but involves both cell autonomous and non-cell autonomous mechanisms. Numerous molecules have been implicated to be involved in the death of MNs.

Heterogeneity effects in the binding of all-trans retinal to bacterio-opsin.

The special trimeric structure of bacteriorhodopsin (bR) in the purple membrane of Halobacterium salinarum, and especially, the still controversial question as to whether the three protein components are structurally and functionally identical, have been subject to considerable work. In the present work, the problem is approached by studying the reconstitution reaction of the bR apo-protein with all-trans retinal, paying special attention to the effects of the apo-protein/retinal (P:R) ratio. The basic observation is that at high P:R values, the reconstitution reaction proceeds via two distinct, fast and slow, pathways associated with two different pre-pigment precursors absorbing at 430 nm (P(430)) and 400 nm (P(400)), respectively.

Light-induced charge redistribution in the retinal chromophore is required for initiating the bacteriorhodopsin photocycle.

Bacteriorhodopsin's photocycle is initiated by the retinal chromophore light absorption. It has usually been assumed that light primarily isomerizes a retinal double bond which in turn induces protein conformational alterations and biological activity. We have studied several artificial pigments derived from retinal analogues tailored to substantially reduce the light-induced chromophore polarization.