Temporal impacts of topical ceftazidime and tobramycin-vancomycin mixtures on the ocular surface microbiota in rabbits.

Antibiotics are one of the important factors that can alter the diversity and composition of ocular surface microbiota. At present, there are a few studies about the antibiotic effect on ocular surface microbiota, including its time-dependent changes. However, these limited studies have revealed various results, and more experiments are required. In this study, we used 16 S rRNA sequencing method to investigate the effects of topical ceftazidime and tobramycin-vancomycin mixtures on the ocular surface microbiota and the temporal changes of the microbiota after discontinuing antibiotic treatment in rabbits. Seventeen healthy rabbits were treated with 5% ceftazidime and a mixture of 0.3% tobramycin-5% vancomycin (CTV) eye drops on one eye four times a day for 7 days. Swab samples of conjunctiva sacs were collected before antibiotic treatment (D0), 12 h after the last antibiotic treatment (D8) and two further time points on Day 15 (D15) and Day 30 (D30). We found that the species diversity of the ocular surface microbiota increased significantly at D8 and was restored at D15, namely, one week after antibiotic cessation. The community structure of the ocular surface microbiota changed after treatment with CTV but recovered at D30. At D8, the relative abundances of 13 bacterial phyla of the initial top 20 phyla and 11 bacterial genera of the initial top 20 genera were significantly different from the relative abundances of the phyla and genera at D0. Furthermore, the relative abundance of the dominant phylum Epsilonbacteraeota obviously decreased, while Proteobacteria and Bacteroidetes markedly increased. For dominant genera, the relative abundance of Helicobacter notably decreased, while Acinetobacter and Pasteurella greatly increased. Thirteen altered bacterial phyla and 7 of 11 altered bacterial genera recovered to preantibiotic levels at D30. In addition, there was a group of nondominant and rare bacteria enriched at D8, and most of them were restored at D30. In conclusion, the species diversity, community structure and composition of the ocular surface microbiota changed greatly after exposure to CTV, but they tended to be restored within weeks after discontinuing antibiotic treatment.

Action Video Gaming Experience Related to Altered Resting-State EEG Temporal and Spatial Complexity.

Action video gaming (AVG) places sustained cognitive load on various behavioral systems, thus offering new insights into learning-related neural plasticity. This study aims to determine whether AVG experience is associated with resting-state electroencephalogram (rs-EEG) temporal and spatial complexity, and if so, whether this effect is observable across AVG subgenres. Two AVG games - League of Legends (LOL) and Player Unknown's Battle Grounds (PUBG) that represent two major AVG subgenres - were examined. We compared rs-EEG microstate and omega complexity between LOL experts and non-experts (Experiment 1) and between PUBG experts and non-experts (Experiment 2). We found that the experts and non-experts had different rs-EEG activities in both experiments, thus revealing the adaptive effect of AVG experience on brain development. Furthermore, we also found certain subgenre-specific complexity changes, supporting the recent proposal that AVG should be categorized based on the gaming mechanics of a specific game rather than a generic genre designation.

Effect of Red Blood Cell Storage Duration on Outcomes of Isolated Traumatic Brain Injury.

BACKGROUND The aim of this study was to investigate the effects of red blood cell (RBC) storage duration on the outcomes of adult isolated traumatic brain injury (iTBI) patients after transfusion. MATERIAL AND METHODS A total of 1252 adult iTBI patients who received the fresh RBCs (stored for £14 days) or old RBCs (stored for >14 days) were finally enrolled in this study. The primary outcome was 90-day mortality. The secondary outcomes were in-hospital mortality, nosocomial infection, and complications. RESULTS By 90 days after RBC transfusion, 89 patients (17.0%) had died in the fresh RBC group, and 107 had died (14.7%) in the old RBC group, with no significant difference in 90-day mortality between the 2 groups (OR=1.192, 95% CI: 0.877-1.620, P=0.261). According to ISS score, no differences were discovered in mild injury (OR=1.079, 95% CI: 0.682-1.707, P=0.746), severe injury (OR=1.055, 95% CI: 0.634-1.755, P=0.838), and more severe injury (OR=1.940, 95% CI: 0.955-3.943, P=0.064). For GCS score, there were no differences in mild injury (OR=1.546, 95% CI: 0.893-2.676, P=0.118), moderate injury (OR=0.965, 95% CI: 0.616-1.513, P=0.877), and severe injury (OR=1.332, 95% CI: 0.677-2.620, P=0.406). We also observed no significant differences in secondary outcomes. CONCLUSIONS Use of old RBCs did not increase the 90-day mortality in adult iTBI patients.

Action Real-Time Strategy Gaming Experience Related to Enhanced Capacity of Visual Working Memory.

Action real-time strategy gaming (ARSG)-a major genre of action video gaming (AVG)-has both action and strategy elements. ARSG requires attention, visual working memory (VWM), sensorimotor skills, team cooperation, and strategy-making abilities, thus offering promising insights into the learning-induced plasticity. However, it is yet unknown whether the ARSG experience is related to the development of VWM capacity. Using both behavioral and event-related potential (ERP) measurements, this study tested whether ARSG experts had larger VWM capacity than non-experts in a change detection task. The behavioral results showed that ARSG experts had higher accuracy and larger VWM capacity than non-experts. In addition, the ERP results revealed that the difference wave of the contralateral delay activity (CDA) component (size 4-size 2) elicited by experts was significantly larger than that of non-experts, suggesting that the VWM capacity was higher in experts than in non-experts. Thus, the findings suggested that prolonged ARSG experience is correlative with the enhancement of VWM.

How does the nickel pincer complex catalyze the conversion of CO2 to a methanol derivative? A computational mechanistic study.

The mechanistic details of nickel-catalyzed reduction of CO(2) with catecholborane (HBcat) have been studied by DFT calculations. The nickel pincer hydride complex ({2,6-C(6)H(3)(OP(t)Bu(2))(2)}NiH = [Ni]H) has been shown to catalyze the sequential reduction from CO(2) to HCOOBcat, then to CH(2)O, and finally to CH(3)OBcat. Each process is accomplished by a two-step sequence at the nickel center: the insertion of a C═O bond into [Ni]H, followed by the reaction of the insertion product with HBcat. Calculations have predicted the difficulties of observing the possible intermediates such as [Ni]OCH(2)OBcat, [Ni]OBcat, and [Ni]OCH(3), based on the low kinetic barriers and favorable thermodynamics for the decomposition of [Ni]OCH(2)OBcat, as well as the reactions of [Ni]OBcat and [Ni]OCH(3) with HBcat. Compared to the uncatalyzed reactions of HBcat with CO(2), HCOOBcat, and CH(2)O, the nickel hydride catalyst accelerates the H(δ-) transfer by lowering the barriers by 30.1, 12.4, and 19.6 kcal/mol, respectively. In general, the catalytic role of the nickel hydride is similar to that of N-heterocyclic carbene (NHC) catalyst in the hydrosilylation of CO(2). However, the H(δ-) transfer mechanisms used by the two catalysts are completely different. The H(δ-) transfer catalyzed by [Ni]H can be described as hydrogen being shuttled from HBcat to nickel center and then to the C═O bond, and the catalyst changes its integrity during catalysis. In contrast, the NHC catalyst simply exerts an electronic influence to activate either the silane or CO(2), and the integrity of the catalyst remains intact throughout the catalytic cycle. The comparison between [Ni]H and Cp(2)Zr(H)Cl in the stoichiometric reduction of CO(2) has suggested that ligand sterics and metal electronic properties play critical roles in controlling the outcome of the reaction. A bridging methylene diolate complex has been previously observed in the zirconium system, whereas the analogous [Ni]OCH(2)O[Ni] is not a viable intermediate, both kinetically and thermodynamically. Replacing HBcat with PhSiH(3) in the nickel-catalyzed reduction of CO(2) results in a high kinetic barrier for the reaction of [Ni]OOCH with PhSiH(3). Switching silanes to HBcat in NHC-catalyzed reduction of CO(2) generates a very stable NHC adduct of HCOOBcat, which makes the release of NHC less favorable.

Starlike aluminum-carbon aromatic species.

Is it possible to achieve molecules with starlike structures by replacing the H atoms in (CH)(n)(q) aromatic hydrocarbons with aluminum atoms in bridging positions? Although D(4h) C(4)Al(4)(2-) and D(2) C(6)Al(6) are not good prospects for experimental realization, a very extensive computational survey of fifty C(5)Al(5)(-) isomers identified the starlike D(5h) global minimum with five planar tetracoordinate carbon atoms to be a promising candidate for detection by photoelectron detachment spectroscopy. BOMD (Born-Oppenheimer molecular dynamics) simulations and high-level theoretical computations verified this conclusion. The combination of favorable electronic and geometric structural features (including aromaticity and optimum C-Al-C bridge bonding) stabilizes the C(5)Al(5)(-) star preferentially.

Control performance and biomembrane disturbance of carbon nanotube artificial water channels by nitrogen-doping.

To establish ways to control the performance of artificial water channels is a big challenge. With molecular dynamics studies, we found that water flow inside the water channels of carbon nanotubes (CNTs) can be controlled by reducing or intensifying interaction energy between water molecules and the wall of the CNTs channel. A way of example toward this significant goal was demonstrated by the doping of nitrogen into the wall of CNTs. Different ratios of nitrogen doping result in different controllable water performance which is dominated mainly through a gradient of van der Waals forces created by the heteroatom doping in the wall of CNTs. Further results revealed that the nitrogen-doped CNT channels show less influence on the integrality of biomembrane than the pristine one, while the nitrogen-doped double-walled carbon nanotube exhibits fewer disturbances to the cellular membrane integrality than the nitrogen-doped single-walled carbon nanotube when interacting with biomembranes.

Computationally designed families of flat, tubular, and cage molecules assembled with "starbenzene" building blocks through hydrogen-bridge bonds.

Using density functional calculations, we demonstrate that the planarity of the nonclassical planar tetracoordinate carbon (ptC) arrangement can be utilized to construct new families of flat, tubular, and cage molecules which are geometrically akin to graphenes, carbon nanotubes, and fullerenes but have fundamentally different chemical bonds. These molecules are assembled with a single type of hexagonal blocks called starbenzene (D(6h) C(6)Be(6)H(6)) through hydrogen-bridge bonds that have an average bonding energy of 25.4-33.1 kcal mol(-1). Starbenzene is an aromatic molecule with six pi electrons, but its carbon atoms prefer ptC arrangements rather than the planar trigonal sp(2) arrangements like those in benzene. Various stability assessments indicate their excellent stabilities for experimental realization. For example, one starbenzene unit in an infinite two-dimensional molecular sheet lies on average 154.1 kcal mol(-1) below three isolated linear C(2)Be(2)H(2) (global minimum) monomers. This value is close to the energy lowering of 157.4 kcal mol(-1) of benzene relative to three acetylene molecules. The ptC bonding in starbenzene can be extended to give new series of starlike monocyclic aromatic molecules (D(4h) C(4)Be(4)H(4)(2-), D(5h) C(5)Be(5)H(5)(-), D(6h) C(6)Be(6)H(6), D(7h) C(7)Be(7)H(7)(+), D(8h) C(8)Be(8)H(8)(2-), and D(9h) C(9)Be(9)H(9)(-)), known as starenes. The starene isomers with classical trigonal carbon sp(2) bonding are all less stable than the corresponding starlike starenes. Similarly, lithiated C(5)Be(5)H(5) can be assembled into a C(60)-like molecule. The chemical bonding involved in the title molecules includes aromaticity, ptC arrangements, hydrogen-bridge bonds, ionic bonds, and covalent bonds, which, along with their unique geometric features, may result in new applications.

A bifunctional strategy towards experimentally (synthetically) attainable molecules with planar tetracoordinate carbons.

Bifunctional strategy, including efficiently utilizing valence electrons and offering steric protection, has been proposed to advance C(2)Al(4) global minimum with double planar tetracoordinate carbons (ptC) to a new family of ptC molecules which could be promising for synthetic realization.