Substituent Effects in π-Hole Regium Bonding Interactions Between Au(p-X-Py)2 Complexes and Lewis Bases: An ab initio Study.

Long range substituent effects in regium bonding interactions involving Au(I) linear complexes are investigated for the first time. The Au(I) atom is coordinated to two para-substituted pyridine ligands. The interaction energy (RI-MP2/def2-TZVP level of theory) of the π-hole regium bonding assemblies is affected by the pyridine substitution. The Hammett's plot representations for several sets of Lewis bases have been carried out and, in all cases, good regression plots have been obtained (interaction energies vs. Hammett's σ parameter). The Bader's theory of "atoms-in-molecules" has been used to evidence that the electron density computed at the bond critical point that connects the Au-atom to the electron donor can be used as a measure of bond order in regium bonding. Several X-ray structures retrieved from the Cambridge Structural Database (CSD) provide experimental support to the existence of π-hole regium bonding in [Au(Py)2 ]+ derivatives.

Enhanced Performance of Zn/Br Flow Battery Using N-Methyl-N-Propylmorpholinium Bromide as Complexing Agent.

Redox flow batteries (RFB) are one of the most interesting technologies in the field of energy storage, since they allow the decoupling of power and capacity. Zinc-bromine flow batteries (ZBFB) are a type of hybrid RFB, as the capacity depends on the effective area of the negative electrode (anode), on which metallic zinc is deposited during the charging process. Gaseous bromine is generated at the positive electrode (cathode) during the charging process, so the use of bromine complexing agents (BCA) is very important. These BCAs are quaternary amines capable of complexation with bromine and generating an organic phase, immiscible with the aqueous electrolyte. One of the most commonly used BCAs in RFB technology is 4-methylethylmorpholinium bromide (MEM-Br). In this work, an alternative quaternary amine 4-methylpropylmorpholinium bromide (MPM-Br) was studied. MPM-Br was integrated into the electrolyte, and 200 charge-discharge cycles were performed on the resulting ZBFBs. The obtained results were compared with those when MEM-Br was used, and it was observed that the electrolyte with MPM-Br displays a higher resistance in voltage and higher energy efficiency, making it a promising alternative to MEM-Br.

Elasticity spectra as a tool to investigate actin cortex mechanics.

BACKGROUND: The mechanical properties of single living cells have proven to be a powerful marker of the cell physiological state. The use of nanoindentation-based single cell force spectroscopy provided a wealth of information on the elasticity of cells, which is still largely to be exploited. The simplest model to describe cell mechanics is to treat them as a homogeneous elastic material and describe it in terms of the Young's modulus. Beside its simplicity, this approach proved to be extremely informative, allowing to assess the potential of this physical indicator towards high throughput phenotyping in diagnostic and prognostic applications. RESULTS: Here we propose an extension of this analysis to explicitly account for the properties of the actin cortex. We present a method, the Elasticity Spectra, to calculate the apparent stiffness of the cell as a function of the indentation depth and we suggest a simple phenomenological approach to measure the thickness and stiffness of the actin cortex, in addition to the standard Young's modulus. CONCLUSIONS: The Elasticity Spectra approach is tested and validated on a set of cells treated with cytoskeleton-affecting drugs, showing the potential to extend the current representation of cell mechanics, without introducing a detailed and complex description of the intracellular structure.

[Assessment of two frailty scales for the preoperative period]. / Fragilidad: en busca de herramientas de evaluación preoperatoria.

BACKGROUND: In the perioperative context, a frailty evaluation scale must consider certain characteristics such as validation, execution speed, simplicity, the capacity to measure multiple dimensions and not being dependent on a cognitive or physical test that could not be performed prior to surgery. The test should select patients that could benefit from interventions aimed to improve their postoperative outcomes. AIM: To validate two frailty evaluation scales for the perioperative period. MATERIAL AND METHODS: The Risk Analysis Index with local modifications (RAI-M) were applied to 201 patients aged 73 ± 7 years (49% women) and the Edmonton frailty scale were applied in 151 patients aged 73 ± 7 years (49% women) in the preoperative period. Their results were compared with the Rockwood frailty index. RESULTS: The Edmonton frail scale showed adequate psychometric properties and assessed multiple dimensions through 8 of the 11 original questions, achieving a discrimination power over 80% compared to the Rockwood Index. The RAI- M, demonstrated solid psychometric properties with a tool that examines 4 dimensions of frailty through 15 questions and reviewing the presence of 11 medical comorbidities. This scale had a discrimination power greater than 85% and it was significantly associated with prolongation of the planned hospital stay and mortality. CONCLUSIONS: RAI-M is a short and easily administered scale, useful to detect frailty in the preoperative period.

Photon Dissipation as the Origin of Information Encoding in RNA and DNA.

Ultraviolet light incident on organic material can initiate its spontaneous dissipative structuring into chromophores which can catalyze their own replication. This may have been the case for one of the most ancient of all chromophores dissipating the Archean UVC photon flux, the nucleic acids. Oligos of nucleic acids with affinity to particular amino acids which foment UVC photon dissipation would most efficiently catalyze their own reproduction and thus would have been selected through non-equilibrium thermodynamic imperatives which favor dissipation. Indeed, we show here that those amino acids with characteristics most relevant to fomenting UVC photon dissipation are precisely those with greatest chemical affinity to their codons or anticodons. This could provide a thermodynamic basis for the specificity in the amino acid-nucleic acid interaction and an explanation for the accumulation of information in nucleic acids since this information is relevant to the optimization of dissipation of the externally imposed thermodynamic potentials. The accumulation of information in this manner provides a link between evolution and entropy production.

Ordered mesoporous carbons obtained by a simple soft template method as sulfur immobilizers for lithium-sulfur cells.

Carbon materials with ordered mesoporous structures were synthesized using soft template methods and then activated by CO2 treatment. Sulfur was incorporated in these carbons via a simple chemical deposition method in aqueous solutions and the resulting composites were tested as electrodes in Li-S cells. The electrochemical results showed that well-ordered mesoporous carbons perform better than those with a random mesopore arrangement (wormhole-like mesoporous structure). The mesopore ordering yields a framework of well-connected empty sites that results in an enhancement of both the charge carrier mobility and the reversibility of the electrochemical reaction. Although the activation with CO2 partially destroys the mesopore arrangement, which adversely affects the electrode performance, it notably increases the surface area and the micropore content which improves the connectivity between the mesopores. The final observation was an irrelevant effect of the activation process at low current densities. However, at higher rates the activated carbon composite delivered higher capacities. The hierarchical pore structure formed by micro- and mesopores should guarantee the required fast mobility of the Li(+).

Laser-induced vapor nanobubbles for B16-F10 melanoma cell killing and intracellular delivery of chemotherapeutics.

The most lethal form of skin cancer is cutaneous melanoma, a tumor that develops in the melanocytes, which are found in the epidermis. The treatment strategy of melanoma is dependent on the stage of the disease and often requires combined local and systemic treatment. Over the years, systemic treatment of melanoma has been revolutionized and shifted toward immunotherapeutic approaches. Phototherapies like photothermal therapy (PTT) have gained considerable attention in the field, mainly because of their straightforward applicability in melanoma skin cancer, combined with the fact that these strategies are able to induce immunogenic cell death (ICD), linked with a specific antitumor immune response. However, PTT comes with the risk of uncontrolled heating of the surrounding healthy tissue due to heat dissipation. Here, we used pulsed laser irradiation of endogenous melanin-containing melanosomes to induce cell killing of B16-F10 murine melanoma cells in a non-thermal manner. Pulsed laser irradiation of the B16-F10 cells resulted in the formation of water vapor nanobubbles (VNBs) around endogenous melanin-containing melanosomes, causing mechanical cell damage. We demonstrated that laser-induced VNBs are able to kill B16-F10 cells with high spatial resolution. When looking more deeply into the cell death mechanism, we found that a large part of the B16-F10 cells succumbed rapidly after pulsed laser irradiation, reaching maximum cell death already after 4 h. Practically all necrotic cells demonstrated exposure of phosphatidylserine on the plasma membrane and caspase-3/7 activity, indicative of regulated cell death. Furthermore, calreticulin, adenosine triphosphate (ATP) and high-mobility group box 1 (HMGB1), three key damage-associated molecular patterns (DAMPs) in ICD, were found to be exposed from B16-F10 cells upon pulsed laser irradiation to an extent that exceeded or was comparable to the bona fide ICD-inducer, doxorubicin. Finally, we could demonstrate that VNB formation from melanosomes induced plasma membrane permeabilization. This allowed for enhanced intracellular delivery of bleomycin, an ICD-inducing chemotherapeutic, which further boosted cell death with the potential to improve the systemic antitumor immune response.

Spatial ecology of Haemophilus and Aggregatibacter in the human oral cavity.

Haemophilus and Aggregatibacter are two of the most common bacterial genera in the human oral cavity, encompassing both commensals and pathogens of substantial ecological and medical significance. In this study, we conducted a metapangenomic analysis of oral Haemophilus and Aggregatibacter species to uncover genomic diversity, phylogenetic relationships, and habitat specialization within the human oral cavity. Using three metrics-pangenomic gene content, phylogenomics, and average nucleotide identity (ANI)-we first identified distinct species and sub-species groups among these genera. Mapping of metagenomic reads then revealed clear patterns of habitat specialization, such as Aggregatibacter species predominantly in dental plaque, a distinctive Haemophilus parainfluenzae sub-species group on the tongue dorsum, and H. sp. HMT-036 predominantly in keratinized gingiva and buccal mucosa. In addition, we found that supragingival plaque samples contained predominantly only one out of the three taxa, H. parainfluenzae, Aggregatibacter aphrophilus, and A. sp. HMT-458, suggesting independent niches or a competitive relationship. Functional analyses revealed the presence of key metabolic genes, such as oxaloacetate decarboxylase, correlated with habitat specialization, suggesting metabolic versatility as a driving force. Additionally, heme synthesis distinguishes H. sp. HMT-036 from closely related Haemophilus haemolyticus, suggesting that the availability of micronutrients, particularly iron, was important in the evolutionary ecology of these species. Overall, our study exemplifies the power of metapangenomics to identify factors that may affect ecological interactions within microbial communities, including genomic diversity, habitat specialization, and metabolic versatility. IMPORTANCE: Understanding the microbial ecology of the mouth is essential for comprehending human physiology. This study employs metapangenomics to reveal that various Haemophilus and Aggregatibacter species exhibit distinct ecological preferences within the oral cavity of healthy individuals, thereby supporting the site-specialist hypothesis. Additionally, it was observed that the gene pool of different Haemophilus species correlates with their ecological niches. These findings shed light on the significance of key metabolic functions in shaping microbial distribution patterns and interspecies interactions in the oral ecosystem.

A new species of terrestrial toad of the Rhinellafestae group (Anura, Bufonidae) from the highlands of the Central Cordillera of the Andes of Colombia.

The genus Rhinella (Bufonidae) comprises 92 species of Neotropical toads. In Colombia, Rhinella is represented by 22 recognized species, of which nine belong to the Rhinellafestae group. Over the past decade, there has been increasing evidence of cryptic diversity within this group, particularly in the context of Andean forms. Specimens of Rhinella collected in high Andean forests on both slopes of the Central Cordillera in Colombia belong to an undescribed species, Rhinellakumandaysp. nov. Genetic analyses using the mitochondrial 16S rRNA gene indicated that the individuals belong to the festae species group. However, they can be distinguished from other closely related species such as Rhinellaparaguas and Rhinellatenrec by a combination of morphological traits including the presence of tarsal fold, a moderate body size, and substantial genetic divergence in the 16S rRNA gene (> 5%). Through this integrative approach, the specimens from the Central Cordillera of Colombia are considered an evolutionary divergent lineage that is sister to R.paraguas, and described as a new species. Rhinellakumandaysp. nov. is restricted to the Central Cordillera of Colombia inhabiting both slopes in the departments of Caldas and Tolima, in an elevational range between 2420 and 3758 m. With the recognition of this new species, the genus Rhinella now comprises 93 species with 23 of them found in Colombia, and ten species endemic to the country.

Electrochemical performance of a graphene nanosheets anode in a high voltage lithium-ion cell.

We demonstrate the feasibility of a lithium ion battery (LIB) using graphene nanosheets (GNS) as the anode in combination with a LiNi(0.5)Mn(1.5)O4 (LNMO) high voltage, spinel-structure cathode. The GNS anode is characterized by a reversible capacity of the order of 600 mA h g(-1) and a working voltage of around 0.9 V, while the 4.8-V cathode has a theoretical capacity of 146.7 mA h g(-1). The full GNS/LiNi(0.5)Mn(1.5)O4 cell has an average working voltage of about 3.75 V and a capacity of the order of 100 mA h g(-1). The findings of this paper suggest that the graphene may be proposed as a suitable anode for application in lithium ion batteries.

Synergy between highly dispersed Ni nanocrystals and graphitized carbon derived from a single source as a strategy for high performance Lithium-Sulfur batteries.

Due to their higher energy density, lower prices, and more environmentally friendly active components, Li-S batteries will soon compete with the current Li-ion batteries. However, issues persist that hinder this implementation, such as the poor conductivity of S and sluggish kinetics due to the polysulfide shuttle, among others. Herein, Ni nanocrystals encapsulated in a C matrix are obtained by a novel strategy based on the thermal decomposition of a Ni oleate-oleic acid complex at low-to-moderate temperatures: 500 and 700 °C. The two C/Ni composites were employed as hosts in Li-S batteries. Although the C matrix is amorphous at 500 °C, it is highly graphitized at 700 °C. At this moderate temperature, the simultaneous generation of Ni nanocrystals and the carbon matrix enhances the catalytic activity of Ni toward the graphitization process, which is negligible if starting from a mixture of a Ni salt and carbon source, even when calcined at temperatures as high as 1000 °C. The electrode made from the C/Ni composite obtained at 700 °C exhibits a high reversible capacity and an enhanced rate capability, much better not only than the C/Ni composite obtained at 500 °C but than others based on amorphous C calcined at very high temperatures, around 1000 °C. These properties are attributed to an increase in the electrical conductivity parallel to the ordering of the layers. We believe this work provides a new strategy to design C-based composites capable of combining the formation of nanocrystalline phases and the control of the C structure with superior electrochemical properties for Li-S batteries.

Diffusional Features of a Lithium-Sulfur Battery Exploiting Highly Microporous Activated Carbon.

Diffusion processes at the electrode/electrolyte interphase drives the performance of lithium-sulfur batteries, and activated carbon (AC) can remarkably vehicle ions and polysulfide species throughout the two-side liquid/solid region of the interphase. We reveal original findings such as the values of the diffusion coefficient at various states of charge of a Li-S battery using a highly porous AC, its notable dependence on the adopted techniques, and the correlation of the diffusion trend with the reaction mechanism. X-ray photoelectron spectroscopy (XPS) and X-ray energy dispersive spectroscopy (EDS) are used to identify in the carbon derived from bioresidues heteroatoms such as N, S, O and P, which can increase the polarity of the C framework. The transport properties are measured by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic intermittent titration technique (GITT). The study reveals Li+ -diffusion coefficient (DLi + ) depending on the technique, and values correlated with the cell state of charge. EIS, CV, and GITT yield a DLi + within 10-7 -10-8  cm2 s-1 , 10-8 -10-9  cm2 s-1 , and 10-6 -10-12  cm2 s-1 , respectively, dropping down at the fully discharged state and increasing upon charge. GITT allows the evaluation of DLi + during the process and evidences the formation of low-conducting media upon discharge. The sulfur composite delivers in a Li-cell a specific capacity ranging from 1300 mAh g-1 at 0.1 C to 700 mAh g-1 at 2C with a S loading of 2 mg cm-2 , and from 1000 to 800 mAh g-1 at 0.2C when the S loading is raised to 6 mg cm-2 .

Site Specialization of Human Oral Veillonella Species.

Veillonella species are abundant members of the human oral microbiome with multiple interspecies commensal relationships. Examining the distribution patterns of Veillonella species across the oral cavity is fundamental to understanding their oral ecology. In this study, we used a combination of pangenomic analysis and oral metagenomic information to clarify Veillonella taxonomy and to test the site specialist hypothesis for the Veillonella genus, which contends that most oral bacterial species are adapted to live at specific oral sites. Using isolate genome sequences combined with shotgun metagenomic sequence data, we showed that Veillonella species have clear, differential site specificity: Veillonella parvula showed strong preference for supra- and subgingival plaque, while closely related V. dispar, as well as more distantly related V. atypica, preferred the tongue dorsum, tonsils, throat, and hard palate. In addition, the provisionally named Veillonella sp. Human Microbial Taxon 780 showed strong site specificity for keratinized gingiva. Using comparative genomic analysis, we identified genes associated with thiamine biosynthesis and the reductive pentose phosphate cycle that may enable Veillonella species to occupy their respective habitats. IMPORTANCE Understanding the microbial ecology of the mouth is fundamental for understanding human physiology. In this study, metapangenomics demonstrated that different Veillonella species have clear ecological preferences in the oral cavity of healthy humans, validating the site specialist hypothesis. Furthermore, the gene pool of different Veillonella species was found to be reflective of their ecology, illuminating the potential role of vitamins and carbohydrates in determining Veillonella distribution patterns and interspecies interactions.

Site-specialization of human oral Gemella species.

Gemella species are core members of the human oral microbiome in healthy subjects and are regarded as commensals, although they can cause opportunistic infections. Our objective was to evaluate the site-specialization of Gemella species among various habitats within the mouth by combining pangenomics and metagenomics. With pangenomics, we identified genome relationships and categorized genes as core and accessory to each species. With metagenomics, we identified the primary oral habitat of individual genomes. Our results establish that the genomes of three species, G. haemolysans, G. sanguinis and G. morbillorum, are abundant and prevalent in human mouths at different oral sites: G. haemolysans on buccal mucosa and keratinized gingiva; G. sanguinis on tongue dorsum, throat, and tonsils; and G. morbillorum in dental plaque. The gene-level basis of site-specificity was investigated by identifying genes that were core to Gemella genomes at a specific oral site but absent from other Gemella genomes. The riboflavin biosynthesis pathway was present in G. haemolysans genomes associated with buccal mucosa but absent from the rest of the genomes. Overall, metapangenomics show that Gemella species have clear ecological preferences in the oral cavity of healthy humans and provides an approach to identifying gene-level drivers of site specificity.

Variability in the indication of brain CT scan after mild traumatic brain injury. A transnational survey.

PURPOSE: Clinical guidelines have been developed to standardize the management of mild traumatic brain injury (mTBI) in the emergency room, in particular the indication of brain CT scan and the use of blood biomarkers. The objective of this study was to determine the degree of adherence to guidelines in the management of these patients across four countries of Southern Europe. METHODS: An electronic survey including structural and general management of mTBI patients and six clinical vignettes was conducted. In-charge physicians from France, Spain, Greece and Portugal were contacted by telephone and email. Differences among countries were searched using an unconditional approach test on contingency tables. RESULTS: One hundred and eighty eight physicians from 131 Hospitals (78 Spain, 36 France, 12 Greece and 5 Portugal) completed the questionnaire. There were differences regarding the in-charge specialist across these countries. There was variability in the use of guidelines and their adherence. Spain was the country with the least guideline adherence. There was a global agreement in ordering a brain CT for patients receiving anticoagulation or platelet inhibitors, and for patients with seizures, altered consciousness, neurological deficit, clinical signs of skull fracture or signs of facial fracture. Aging was not an indication for CT in French centres. Loss of consciousness and posttraumatic amnesia were considered as indications for CT more frequently in Spain than in France. These findings were in line with the data from the 6 clinical vignettes. The estimated use of CT reached around 50% of mTBI cases. The use of S100B is restricted to five French centres. CONCLUSIONS: There were large variations in the guideline adherence, especially in the situations considered to order brain CT after mTBI.

Vapor-phase fabrication of ß-iron oxide nanopyramids for lithium-ion battery anodes.

The other polymorph: A vapor-phase route for the fabrication of ß-Fe(2)O(3) nanomaterials on Ti substrates at 400-500 °C is reported. For the first time, the ß polymorph is tested as anode for lithium batteries, exhibiting promising performances in terms of Li storage and rate capability.

Site-tropism of streptococci in the oral microbiome.

A detailed understanding of where bacteria localize is necessary to advance microbial ecology and microbiome-based therapeutics. The site-specialist hypothesis predicts that most microbes in the human oral cavity have a primary habitat type within the mouth where they are most abundant. We asked whether this hypothesis accurately describes the distribution of the members of the genus Streptococcus, a clinically relevant taxon that dominates most oral sites. Prior analysis of 16S rRNA gene sequencing data indicated that some oral Streptococcus clades are site-specialists while others may be generalists. However, within complex microbial populations composed of numerous closely related species and strains, such as the oral streptococci, genome-scale analysis is necessary to provide the resolution to discriminate closely related taxa with distinct functional roles. Here, we assess whether individual species within this genus are specialists using publicly available genomic sequence data that provide species-level resolution. We chose a set of high-quality representative genomes for human oral Streptococcus species. Onto these genomes, we mapped shotgun metagenomic sequencing reads from supragingival plaque, tongue dorsum, and other sites in the oral cavity. We found that every abundant Streptococcus species in the healthy human oral cavity showed strong site-tropism and that even closely related species such as S. mitis, S. oralis, and S. infantis specialized in different sites. These findings indicate that closely related bacteria can have distinct habitat distributions in the absence of dispersal limitation and under similar environmental conditions and immune regimes. Substantial overlap between the core genes of these three species suggests that site-specialization is determined by subtle differences in genomic content.

Use of olive biomass fly ash in the preparation of environmentally friendly mortars.

The incorporation of fly ash from olive biomass (FAOB) combustion in cogeneration plants into cement based mortars was explored by analyzing the chemical composition, mineralogical phases, particle size, morphology, and IR spectra of the resulting material. Pozzolanic activity was detected and found to be related with the presence of calcium aluminum silicates phases. The preparation of new olive biomass fly ash content mortars is effective by replacing either CaCO(3) filler or cement with FAOB. In fact, up to 10% of cement can be replaced without detracting from the mechanical properties of a mortar. This can provide an alternative way to manage the olive biomass fly ash as waste produced in thermal plants and reduce cement consumption in the building industry, and hence an economically and environmentally attractive choice.

Biomass Porous Carbons Derived from Banana Peel Waste as Sustainable Anodes for Lithium-Ion Batteries.

Disordered carbons derived from banana peel waste (BPW) were successfully obtained by employing a simple one-step activation/carbonization method. Different instrumental techniques were used to characterize the structural, morphological, and textural properties of the materials, including X-ray diffraction, thermogravimetric analysis, porosimetry and scanning electron microscopy with energy-dispersive X-ray spectroscopy. The chemical activation with different porogens (zinc chloride, potassium hydroxide and phosphoric acid) could be used to develop functional carbonaceous structures with high specific surface areas and significant quantities of pores. The BPW@H3PO4 carbon exhibited a high specific surface area (815 m2 g-1), chemical stability and good conductivity for use as an anode in lithium-ion batteries. After 200 cycles, this carbon delivered a reversible capacity of 272 mAh g-1 at 0.2 C, showing a notable retention capacity and good cycling performance even at high current densities, demonstrating its effectiveness and sustainability as an anode material for high-energy applications in Li-ion batteries.

Acoustofluidic phase microscopy in a tilted segmentation-free configuration.

A low-cost device for registration-free quantitative phase microscopy (QPM) based on the transport of intensity equation of cells in continuous flow is presented. The method uses acoustic focusing to align cells into a single plane where all cells move at a constant speed. The acoustic focusing plane is tilted with respect to the microscope's focal plane in order to obtain cell images at multiple focal positions. As the cells are displaced at constant speed, phase maps can be generated without the need to segment and register individual objects. The proposed inclined geometry allows for the acquisition of a vertical stack without the need for any moving part, and it enables a cost-effective and robust implementation of QPM. The suitability of the solution for biological imaging is tested on blood samples, demonstrating the ability to recover the phase map of single red blood cells flowing through the microchip.