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In this communication, we present a novel method to measure local optical dichroism (OD) in opaque crystal powder suspensions using photoacoustic (PA) effect. Our method is based upon the novel laser speckle contrast technique, in combination with a simple statistical approach, we were able to measure the OD of chiral crystals suspensions under completely random orientation.

Practical implementation of anion exchange membrane fuel cells mainly relies on the choice of highly active and stable oxygen reduction reaction (ORR) catalysts. Transition metal oxides based on Group 4 and 5 are well known for their chemical stability and corrosion‐resistance and they are earth‐abundant too. Among them, zirconia (ZrO2) has exceptional chemical stability, but its poor conductivity and less active sites hinder the application of zirconia‐based materials toward ORR. In order to bring out the best activity from ZrO2, careful site engineering without losing the phase purity and chemical stability is essential. In this context, nitrogen doping on tetragonal zirconia (t‐ZrO2) as a viable method to obtain a highly active ORR catalyst is adopted. The temperature for the phase pure synthesis of t‐ZrO2 is optimized by crystallographic study. The nitrogen doping in the zirconia lattice is confirmed by various …

In this work, sorbents based on natural zeolite (Z) and chamotte clay (ChC) treated with NaCl and HNO3 solutions were obtained to extract Na+ and K+ ions from saline water. The physicochemical characteristics of the obtained sorbents were studied by SEM, EDAX, and BET methods. It was found that successive treatment with NaCl and HNO3 solutions has a positive effect on the sorption properties of the studied materials. The maximum increase in the specific surface area from 4.5 m2/g to 39.3 m2/g is observed for acid-treated Z, and the specific surface area of ChC also increases almost 2-fold from 8.4 m2/g to 15.3 m2/g. Na+ and K+ ions are extracted from water due to ion exchange with Z and ChC cations. As a result of determining the cation exchange capacity (CEC) of the studied sorbents, it was found that treatment with a NaCl solution improves the ion exchange properties of the sorbent and leads to the formation of a “homoionic” form of aluminosilicates. Due to that the sorbents more easily enter ion exchange reactions. The authors established the sorption activity of the obtained materials based on natural Z and ChC with respect to Na+ and K+ cations. The maximum recovery rate is 28.45% for Na+ ions with the ChC-Na-H sorbent and 76.28% for K+ ions with the ChC-Na sorbent. Among Z-based sorbents, the most effective forms are Z-Na-H (15.44% Na+ recovery) and Z-Na (60.47% K+ recovery).

Chiral surfaces, developed in the last decade, serve as media for enantioselective chemical reactions. Until today, they have been based mostly on developments in silica templating, and are made mainly from imprints of silicate materials developed a long time ago. Here, a chiral porous activated carbon surface was developed based on a chiral ionic liquid, and the surface chemistry and pore structure were studied to lay a new course of action in the field. The enantioselectivities of surfaces are examined by using variety of methods such as circular dichroism, linear sweep voltammetry and catalysis. These techniques revealed a 28.1% preference for the D enantiomer of the amino acid proline, and linear sweep voltammetry confirmed chirality recognition by another probe. An aldol surface chiral catalytic reaction was devised and allowed to determine the root of the enantiomeric excess. These results affirm the path …

Atomic and molecular layer deposition (ALD and MLD) are techniques based on surface‐directed self‐limiting reactions that afford deposition of films controlled at the monolayer level and with extreme conformality, even on ultra‐high‐aspect‐ratio and porous substrates. These methodologies are typically used to deposit thin films with desirable physical properties and functionality. Here, the MLD process is harnessed to demonstrate the growth of molecularly thin chiral films that inherit a desirable chemical property directly from the source precursor: using this innovative technique, enantioselective nanosurfaces are managed to be grown. Specifically, the formation of a Zn/Cysteine nanostructure by MLD is demonstrated for both the l‐ and d‐ enantiomers. The reaction and growth mechanism of these chiral hybrid inorganic‐organic nanosurfaces are studied via various experimental procedures; their …

We explore the possibility for implementing nanoscale quantum imaging based on the concept of undetected photons with a pumping beam at x-ray wavelengths. Our proposed scheme exploits the nearly four order of magnitude angular magnification that is a result of the process of the effect of extreme non-degenerate spontaneous down conversion from xrays into optical radiation, which is used for the generation of entangled photon pairs with one x-ray photon and one visible photon. In our scheme the x-ray photons interact with the object and the visible do not interact with the object, but in contrast to other schemes like ghost imaging, only the visible photons are detected. The scheme is sensitive to both the amplitude and the phase variations and can provide resolutions down to a few nanometers, hence can be used as a powerful tool for nanoscale imaging. In the present configuration, the scheme requires very …

Nuclear speckles are nuclear bodies containing RNA-binding proteins as well as RNAs including long non-coding RNAs (lncRNAs). Maternally expressed gene 3 (MEG3) is a nuclear retained lncRNA found to associate with nuclear speckles. To understand the association dynamics of MEG3 lncRNA with nuclear speckles in living cells, we generated a fluorescently tagged MEG3 transcript that could be detected in real time. Under regular conditions, transient association of MEG3 with nuclear speckles was observed, including a nucleoplasmic fraction. Transcription or splicing inactivation conditions, known to affect nuclear speckle structure, showed prominent and increased association of MEG3 lncRNA with the nuclear speckles, specifically forming a ring-like structure around the nuclear speckles. This contrasted with metastasis-associated lung adenocarcinoma (MALAT1) lncRNA that is normally highly associated with nuclear speckles, which was released and dispersed in the nucleoplasm. Under normal conditions, MEG3 dynamically associated with the periphery of the nuclear speckles, but under transcription or splicing inhibition, MEG3 could also enter the center of the nuclear speckle. Altogether, using live-cell imaging approaches, we find that MEG3 lncRNA is a transient resident of nuclear speckles and that its association with this nuclear body is modulated by the levels of transcription and splicing activities in the cell.

Many organisms have an elastic skeleton that consists of a closed shell of epithelial cells that is filled with fluid, and can actively regulate both elastic forces in the shell and hydrostatic pressure inside it. In this work we introduce a simple network model of such pressure-stabilized active elastic shells in which cross-links are represented by material points connected by non-linear springs of some given equilibrium lengths and spring constants. We mimic active contractile forces in the system by changing the parameters of randomly chosen springs and use computer simulations to study the resulting local and global deformation dynamics of the network. We elucidate the statistical properties of these deformations by computing the corresponding distributions and correlation functions. We show that pressure-induced stretching of the network introduces coupling between its local and global behavior: while the network …

The parasite Trypanosoma brucei causes African sleeping sickness that is fatal to patients if untreated. Parasite differentiation from a replicative slender form into a quiescent stumpy form promotes host survival and parasite transmission. Long noncoding RNAs (lncRNAs) are known to regulate cell differentiation in other eukaryotes. To determine whether lncRNAs are also involved in parasite differentiation, we used RNA sequencing to survey the T. brucei genome, identifying 1428 previously uncharacterized lncRNA genes. We find that grumpy lncRNA is a key regulator that promotes parasite differentiation into the quiescent stumpy form. This function is promoted by a small nucleolar RNA encoded within the grumpy lncRNA. snoGRUMPY binds to messenger RNAs of at least two stumpy regulatory genes, promoting their expression. grumpy overexpression reduces parasitemia in infected mice. Our analyses suggest that T. brucei lncRNAs modulate parasite-host interactions and provide a mechanism by which grumpy regulates cell differentiation in trypanosomes.

The growth of ultrathin 1D inorganic nanomaterials with controlled diameters remains challenging by current synthetic approaches. A polymer chain templated method is developed to synthesize ultrathin Bi2O2CO3 nanotubes. This formation of nanotubes is a consequence of registry between the electrostatic absorption of functional groups on polymer template and the growth habit of Bi2O2CO3. The bulk bismuth precursor is broken into nanoparticles and anchored onto the polymer chain periodically. These nanoparticles react with the functional groups and gradually evolve into Bi2O2CO3 nanotubes along the chain. 5.0 and 3.0 nm tubes with narrow diameter deviation are synthesized by using branched polyethyleneimine and polyvinylpyrrolidone as the templates, respectively. Such Bi2O2CO3 nanotubes show a decent lithium‐ion storage capacity of around 600 mA h g−1 at 0.1 A g−1 after 500 cycles, higher …

A novel type of Li/graphene oxide (Li/GO) battery based on a spontaneous redox reaction between Li metal and GO cathode is introduced as an alternative viable primary battery system. Here, we present an efficient synthesis of GO by the modified Hummers method and focus on a comprehensive study of the reduction mechanism. The Li/GO battery was thoroughly analyzed by various physical and electrochemical methods. GO rich in oxygen‐bearing functional groups on graphene layers provided lithium storage sites and delivered a high discharge capacity of around 720 mAh/g at 12 mA/g. Products formed on the surface during reduction were analyzed, and a mechanism was proposed. The results uncovered the reasons underlying the improved electrochemical properties and the contribution of the irreversible capacity of reduced GO in graphene‐based composite electrode materials for metal‐ion batteries …

In their seminal paper, Caves and Schumaker presented a new formalism for quantum optics, intended to serve as a building block for describing two-photon processes, in terms of new, generalized qudratures. The important, revolutionary concept in their formalism was that it was fundamentally two-mode, ie the related observables could not be attributed to any single one of the comprising modes, but rather to a generalized complex quadrature that could only be attributed to both of them. Here, we propose a subtle, but fundamentally meaningful modification to their important work. Unlike the above proposal, we deliberately choose a frequency-agnostic definition of the two-mode quadrature, that we motivate on physical grounds. This simple modification has far-reaching implications to the formalism–the real and imaginary parts of the quadratures now coincide with the famous EPR variables, and our two-mode …

A sports multi-bet is a bet on the results of a set of N games. One type of multi-bet offered by the Israeli government is WINNER 16, where participants guess the results of a set of 16 soccer games. The prizes in WINNER 16 are determined by the accumulated profit in previous rounds, and are split among all winning forms. When the reward increases beyond a certain threshold, a profitable strategy can be devised. Here, we present a machine-learning algorithm scheme to play WINNER 16. Our proposed algorithm is marginally profitable on average in a range of hyper-parameters, indicating inefficiencies in this game. To make a better prize-pricing mechanism we suggest a generalization of the single-bet approach. We studied the expected profit and risk of WINNER 16 after applying our suggestion. Our proposal can make the game more fair and more appealing without reducing the profitability. View Full-Text

Desalination is a critical process to resolve the crisis of insufficient freshwater resources. Among desalination technologies, electrochemical electrode deionization (EEDI) has attracted wide attention because of the advantages in low cost, no secondary pollution, and low energy consumption etc. Electrode materials are the critical factors for determining the performance of EEDI. However, the traditional EEDI with carbon electrode (capacitive deionization, CDI) often showed inefficient desalination capacity, charge efficiency, cycle stability as well as ions selectivity due to the anode oxidation. Therefore, the development of anions-capture materials is crucial for the development of EEDI devices. In this review, the anions-capture materials are classified into four categories according to their capture mechanisms: (i) Electrosorption materials, mainly including conventional and modified carbon materials; (ii) conversion …

Catalyst poisoning is a prominent issue, reducing the lifetime of catalysts and increasing the costs of the processes that rely on them. The electrocatalysts that enable green energy conversion and storage, such as proton exchange membrane fuel cells and hydrogen bromine redox flow batteries, also suffer from this issue, hindering their utilization. Current solutions to protect electrocatalysts from harmful species fall short of effective selectivity without inhibiting the required reactions. This article describes the protection of a standard 50% Pt/C catalyst with a V2O5 coating through atomic layer deposition (ALD). The ALD selectively deposited V2O5 on the Pt, which enhanced hydrogen transport to the Pt surface and resulted in a higher mass activity in alkaline electrolytes. Cyclic voltammetry and X-ray photoelectron spectroscopy showed that the Pt was protected by the coating in the HBr/Br2 electrolyte which dissolved …

Correction to: Specific Susceptibility to COVID-19 in Adults with Down Syndrome NCBI NCBI Logo Skip to main content Skip to navigation Resources How To About NCBI Accesskeys Sign in to NCBI PMC US National Library of Medicine National Institutes of Health Search database Search term Search Advanced Journal list Help Try out PMC Labs and tell us what you think. Learn More. Journal List Nature Public Health Emergency Collection PMC8602985 Logo of phenaturepg Neuromolecular Med. 2021 Nov 19 : 1–2. doi: 10.1007/s12017-021-08695-7 [Epub ahead of print] PMCID: PMC8602985 PMID: 34797469 Correction to: Specific Susceptibility to COVID-19 in Adults with Down Syndrome Tomer Illouz, 1, 2 Arya Biragyn, 3 Milana Frenkel-Morgenstern, 4 Orly Weissberg, 4 Alessandro Gorohovski, 4 Eugene Merzon, 5 Ilan Green, 5 Florencia Iulita, 6, 7, 8, 9 Lisi Flores-Aguilar, 10 Mara Dierssen, 11, 12, 13 Ilario …