Mixed Clusters Research Articles

Ultrafast Dissociation Dynamics Induced in [Fe(CO)5] n Xe m Mixed Clusters by Resonant Femtosecond Infrared Laser Radiation.

Real-time dissociation dynamics induced in [Fe(CO)5] n Xe m mixed molecular clusters by femtosecond IR radiation in the 5 μm region was studied for the first time by means of time-resolved methods based on resonant excitation of C≡O vibrations in the molecular core of the cluster and photoionization probing (λ = 400 nm) of its decay products. It was found that IR-excited clusters in the initially cold particle beam are heated and dissociated as a result of relaxation processes, giving rise to free neutral Xe aggregates and Fe(CO)5 molecules. Thus, the formed particles are the origin of signal variations from Xe+ and Fe(CO)5 + ions, which grow on a picosecond time scale. It is concluded that the initial laser excitation of C≡O vibrations in clusterized molecules is followed by the process of cluster dissociation accompanied with the formation of free neutral particles according to the hierarchy of binding energies: weakly bound shells of Xe atoms are evaporated first and much faster than the Fe(CO)5 molecules from the cluster core. The characteristic times of relaxation processes as well as the cluster temperature were estimated.

Molecular Detection of some Staphylococcal species with the newly developed folp gene sequences

16SrRNA gene sequencing, universally accepted for bacterial identification could not effectively discriminate some closely related Staphylococcal species. For this reason, for bacterial species identification, other DNA sequencing genes are required. In this study, folp gene, encoding DHPS, was tested as a possible and alternative phylogenetic marker for more closely related Staphylococcal species. In this new method, 813 bp were implemented for classification instead of 1447 of 16S rRNA mostly used. Phylogenetic analysis was performed based on DNA sequences obtained from the GenBank including most important Staphylococcal species. As a result, the 16S rRNA-based tree clearly delineated 7 distinct clusters with high bootstrap values (1000) at distance adjusted to 5. Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus hominis, Staphylococcus haemolyticus and Staphylococcus saprophyticus were identified in separate clusters. However, 2 mixed clusters were resolved including Staphylococcus epidermidis and Staphylococcus warneri in one cluster, while Staphylococcus pasteuri and Staphylococcus warneri in the other one. Comparatively, the folp gene-based tree yielded 9 clusters with at distance adjusted to 5 and 1000 bootstrap value. Staphylococcus haemolyticus, Staphylococcus hominis, Staphylococcus haemolyticus, Staphylococcus ludunensis, Staphylococcus epidermidis, Staphylococcus aureus, Staphylococcus saprophyticus, Staphylococcus pasteuri were resolved in separate clusters, however, Staphylococcus warneri and Staphylococcus epidermidis were identified in one mixed cluster. In addition, DNA-DNA relatedness studies indicated high sequence divergence of folp gene exhibiting 61.58-96.48 % interspecies homology compared to 16S rRNA with sequences similarities of 97.09-99.32 %. At the intraspecies level, the nucleotide substitution rates were ranged between 0-25%, mostly at low level for most Staphylococcal species compared to 98.65-99.93 identified in 16S rRNA gene. Moreover, in blind tests, this method was able for correct identification of 13 bacteria isolates of different Staphylococcal species. As a conclusion, folp gene sequences provide better resolution compared to the 16S rRNA gene sequences for both interspecies and interspecies DNA analysis of Staphylococci.

Interactions of alloying Cr/Ti with substitutional solutes and self-interstitial atoms in vanadium

The interactions between alloying Ti/Cr and 14 substitutional solutes/self-interstitial atoms (SIAs) and stability of small interstitial Crm/Tim clusters and Ti/Cr-SIA mixed clusters in vanadium (V) were investigated by first-principles calculations. We calculated the binding energy between Cr/Ti and substitutional solute atoms (Al, Fe, Y, Ta, Cu, Mn, Ni, Nb, Mo, Zr, W, Si, S and P). The Ti can attract most substitutional solutes while Cr repel most of them. For two interstitials, the formation orders of stable configurations are <111>Cr-Cr, mixed <111>Cr-V, <111>SIA, mixed <111>Cr-Ti and <111>Ti-Ti dumbbells. For interstitial Crm, (Cr-Ti)m/2 and Tim clusters with m = 4–12, the most stable configurations are always the parallel 〈111〉 dumbbell, the formation energies of Cr clusters are lower than other clusters. Finally, we explored the interactions between two Cr/Ti atoms and <111>SIA dumbbell as well as the interactions between <111>Cr-Cr dumbbell and solutes. The Ti/Y/Zr/Nb/Ta solutes can attract <111>Cr-Cr dumbbell in similar with the cases of <111>SIA and <111>Cr-V, reducing the mobility of them.

Metabolic diversity in a collection of wild and cultivated Brassica rapa subspecies.

Brassica rapa (B. rapa) and its subspecies contain many bioactive metabolites that are important for plant defense and human health. This study aimed at investigating the metabolite composition and variation among a large collection of B. rapa genotypes, including subspecies and their accessions. Metabolite profiling of leaves of 102 B. rapa genotypes was performed using ultra-performance liquid chromatography coupled with a photodiode array detector and quadrupole time-of-flight mass spectrometry (UPLC-PDA-QTOF-MS/MS). In total, 346 metabolites belonging to different chemical classes were tentatively identified; 36 out of them were assigned with high confidence using authentic standards and 184 were those reported in B. rapa leaves for the first time. The accumulation and variation of metabolites among genotypes were characterized and compared to their phylogenetic distance. We found 47 metabolites, mostly representing anthocyanins, flavonols, and hydroxycinnamic acid derivatives that displayed a significant correlation to the phylogenetic relatedness and determined four major phylometabolic branches; 1) Chinese cabbage, 2) yellow sarson and rapid cycling, 3) the mizuna-komatsuna-turnip-caitai; and 4) a mixed cluster. These metabolites denote the selective pressure on the metabolic network during B. rapa breeding. We present a unique study that combines metabolite profiling data with phylogenetic analysis in a large collection of B. rapa subspecies. We showed how selective breeding utilizes the biochemical potential of wild B. rapa leading to highly diverse metabolic phenotypes. Our work provides the basis for further studies on B. rapa metabolism and nutritional traits improvement.

A density functional theory study of adsorption and dissociation of H2 molecule on small PdnAgm (n + m ≤ 4) metal clusters

The adsorption and dissociation of hydrogen molecule on small PdnAgm (n + m ≤ 4) clusters is studied employing density functional theory (DFT) calculations. The lowest energy structures of the PdnAgm clusters are initially presented. Based on the obtained structures, various geometries of H2 adsorption and dissociation with these clusters are examined. The cluster size and composition of the PdnAgm clusters are found to control the nature of the adsorption process. The results suggest that molecular adsorption is more favorable on the Pd atom and mixed clusters, while hydrogen dissociation is more favorable on the Pdn (n = 2–4) clusters. The Pd dimer and trimer are found to be the most reactive clusters for hydrogen adsorption, while single Ag atom is the least reactive one. The natural bond orbital (NBO) population analysis indicates that hydrogen atoms tend to draw electrons from the metal clusters in the dissociative form and donate electrons to the metal clusters in the molecular adsorption form. The density of states (DOS) of the PdnAgm trimers are also presented and discussed. The interaction and stabilities of cluster on the graphene support has also been performed.

Genetic Diversity and Population Genetic Structure Analysis of Plasmodium knowlesi Thrombospondin-Related Apical Merozoite Protein (TRAMP) in Clinical Samples.

The simian malaria parasite Plasmodium knowlesi causes a high number of zoonotic infections in Malaysia. The thrombospondin-related apical merozoite protein (TRAMP) is an essential ligand for binding to the erythrocyte cell surface, whereby it facilitates the invasion. This study is the first attempt to determine the genetic diversity, phylogeography, natural selection and population structure from 97 full-length PkTRAMP gene sequences originating from Malaysia. We found low levels of nucleotide diversity (π~0.0065) for the full-length gene despite samples originating from geographically separated regions (i.e., Peninsular Malaysia and Malaysian Borneo). The rate of synonymous substitutions was significantly higher than that of non-synonymous substitutions, indicating a purifying selection for the full-length gene within the clinical samples. The population genetic analysis revealed that the parasite population is undergoing a significant population expansion. The analysis of the amino acid sequence alignment of 97 PkTRAMP sequences identified 15 haplotypes, of which a major shared haplotype was noted Hap 1 (n = 68, Sarawak; n = 34, Sabah; n = 12, Peninsular Malaysia; n = 22). The phylogenetic analysis using DNA sequences identified two clusters that separated due to geographical distance and three mixed clusters with samples from both Peninsular Malaysia and Malaysian Borneo. Population structure analyses indicated two distinct sub-populations (K = 2). Our findings point to the potential for independent parasite evolution, which could make zoonotic malaria control and elimination even more challenging.

P8.007: Single Nuclei RNA-Sequencing Unravels Complex Renal And Immune Cells Signaling Driving Fibrosis in Kidney Allografts

Introduction: Chronic allograft dysfunction (CAD), characterized by interstitial fibrosis and tubular atrophy (IFTA), is the main cause of late graft loss in kidney transplantation. This study dissects the molecular and cellular heterogeneity of the human kidney stroma and immune cells driving CAD. Methods: Using single-nuclei RNA sequencing, 41,893 nuclei were evaluated from 8 rare kidney allograft biopsies (6 CAD and 3 normal patients). These needle biopsies were collected on average at ≥15-months posttransplanation and were stored in the cryopreservative, RNAlater. Following, integrative analysis was applied including pathway and enrichment analysis, pseudotime trajectories, and ligand receptor analyses. XY chromosome linked gene expression analysis was also used to determine the origin of both immune and nonimmune cells in sex-mismatch transplants. Results: Two states of fibrosis were discovered (low and high ECM) that differ based on significant alterations in kidney subclusters, immune cell proportions and phenotypes, and intercellular communication. Pseudotime trajectories revealed a mixed tubule cluster, a key intermediate of injured proximal tubular cells, that transitioned to an activated fibroblast cluster also enriched in myofibroblasts markers. Such differentiation of proximal tubular cells was the main driver of fibrosis. Unique to high ECM, MT1 performed replicative repair evidenced by dedifferentiation and nephrogenic transcriptional signatures. Conversely, low ECM did not show a strong replicative repair signature. Differences in immune cell populations highlighted the dynamic nature of immune responses, some of which, promoted severe metabolic dysfunction and limited repair in low ECM or perpetual tissue regeneration and sustained injury in high ECM. Low ECM was characterized by increased dendritic cells (cDCs, pDCs), mast cells, and monocytes (MO1, MO2) whereas high ECM was characterized by increased B cells, T cells (CD8+ T cells, NKs, and Tregs), and plasma cells. Moreover, 65 ligand-receptor pairs between kidney cells and donor-derived macrophages (previously unidentified after several years post-transplantation) played a novel role in injury propagation. Conclusion: This work improves our understanding of targetable cell types and regulatory mechanisms involved in tissue repair. Interventions aimed at graft fibrogenesis likely require a more targeted approach based on the unique molecular pathways characterizing each condition. National Institutes of Health grant R01DK109581. National Institutes of Health grant R01DK122682 (VRM).

TSC/MTOR -associated Eosinophilic Renal Tumors Exhibit a Heterogeneous Clinicopathologic Spectrum : A Targeted Next-generation Sequencing and Gene Expression Profiling Study.

Several TSC1/2- or MTOR -mutated eosinophilic renal tumor subsets are emerging, including eosinophilic solid and cystic renal cell carcinoma (ESC RCC), eosinophilic vacuolated tumors (EVTs) and low-grade oncocytic tumors (LOTs). "Unclassified renal tumors with TSC/MTOR mutations" ( TSC -mt RCC-NOS) do not meet the criteria for other histomolecular subtypes. Whether these tumors represent a continuum of 1 TS C/ MTOR -mutation-associated disease is unknown. We evaluated the clinicopathologic and IHC profiles of 39 eosinophilic renal tumors with targeted DNA sequencing-confirmed TSC/MTOR mutations. Twenty-eight of these, plus 6 ChRCC, 5 RO, 5 ccRCC, 7 MiT RCC and 6 normal renal tissues, were profiled transcriptionally by RNA-seq. The 39 cases were reclassified based on morphological and IHC features as ESC RCC (12), EVT (9), LOT, (8) and TSC -mt RCC-NOS (10). The mutation profiles demonstrated consistency; ESC RCCs (12/12) had TSC mutations, and most LOTs (7/8) had MTOR mutations. Ten TSC -mt RCC-NOSs exhibited heterogeneous morphology, arising a differential diagnosis with other renal tumors, including MiT RCC, PRCC and epithelioid PEComa. RNA sequencing-based clustering segregated ESC RCC, EVT and LOT from each other and other renal tumors, indicating expression profile-level differences. Most TSC- mt RCC-NOSs (6/7) formed a mixed cluster with ESC RCC, indicating similar expression signatures; one TSC- mt RCC-NOS with unusual biphasic morphology clustered with EVT. We expanded the TSC/MTOR -associated eosinophilic renal tumor morphologic spectrum, identified gene mutation characteristics, and highlighted differential diagnosis challenges, especially with MiT RCC. ESC RCC, EVT, and LOT having distinct expression profiles. TSC -mt RCC-NOS may cluster with recognized TSC/MTOR -associated entities.

Prototype of cell for quantum cellular automata: Multimode vibronic model for a two-electron mixed valence molecular square

Multimode vibronic model for the two-electron square-planar mixed valence cluster is developed and applied to analysis of localization-delocalization phenomenon. The model involves interaction of the excess electrons both with “breathing” (Piepho-Krausz-Schatz- PKS-type) vibrations and with the intercenter vibrations modulating electron transfer integrals. We demonstrate that the coupling with two B1g-vbrations can be substituted by the effective coupling with the “interaction mode”. As a result, complex three-mode vibronic problem proves to be reduced to the two-mode problem involving the interaction mode of B1g-symmetry having hybrid nature and pure intercenter A1g-vibration. The analysis of minima of the lower adiabatic potential surface shows that the two vibrations produce competitive effects on the localization-delocalization properties. Thus, the dominating coupling with B1g-vibration is shown to form the double-well adiabatic potential surface, with the electronic pair in each minimum being predominantly localized on one of diagonals of the square, while the dominating coupling with the A1g-mode gives rise to single-well surface describing fully delocalized electronic pair. Finally, keeping in mind applications of square-planar two-electron clusters as molecular cells in quantum cellular automata we reveal the role of different vibrations in the shape of cell–cell response function.

Rational Design of Bimetallic Metal Chalcogenide Clusters for CO2 Dissociation.

Thermochemical dissociation of CO2 on pure, ligated, and mixed transition metal (W, Cu) chalcogenide clusters are investigated using the first-principles gradient-corrected density functional approach. It is shown that although the pure and ligated metal chalcogenide clusters exhibit significantly high barriers for CO2 dissociation, the computed barriers for the mixed clusters are relatively lower. The lowest barrier is obtained for the Cu3W3Se8 cluster, which shows a dramatically reduced barrier height of only 0.41 eV. Detailed analysis reveals that the substitution of W by Cu sites leads to a charge transfer from Cu to W sites, resulting in locally active W sites. The lowering of the CO2 dissociation barriers can be attributed to the facile transfer of charge from the locally active W sites and also due to the alteration of the binding energy of CO2 to the charged W sites. Our studies provide an alternate strategy to design novel thermochemical catalysts for CO2 adsorption and subsequent dissociation.

Implementing a text-messaging intervention for unhealthy alcohol use in emergency departments: protocol for implementation strategy development and a pilot cluster randomized implementation trial

BackgroundUnhealthy alcohol use (UAU) is a leading cause of premature mortality among adults in the USA. Emergency departments (EDs) are key intervention settings for UAU but often have limited time and resources. One low-burden, scalable approach to address UAU is text-messaging interventions. Despite strong research support and promise for scalability, there is little research on how to implement such interventions in healthcare settings. The process of providers making them available to patients in an efficient way within already busy and overburdened ED workflows and patients adopting them remains a new area of research. The purpose of this three-phase study is to develop and test an implementation strategy for UAU text-messaging interventions in EDs.MethodOur first aim is to examine barriers and facilitators to staff offering and patients accepting a text-messaging intervention in the ED using an explanatory, sequential mixed methods approach. We will examine alcohol screening data in the electronic health records of 17 EDs within a large integrated health system in the Northeast and conduct surveys among chairpersons in each. This data will be used to purposively sample 4 EDs for semi-structured interviews among 20 clinical staff, 20 patients, and 4 chairpersons. Our second aim is to conduct a stakeholder-engaged intervention mapping process to develop a multi-component implementation strategy for EDs. Our third aim is to conduct a mixed method 2-arm cluster randomized pilot study in 4 EDs that serve ~11,000 UAU patients per year to assess the feasibility, acceptability, and preliminary effectiveness of the implementation strategy. The Integrated Promoting Action on Research Implementation in Health Services framework will guide study activities.DiscussionLow-burden technology, like text messaging, along with targeted implementation support and strategies driven by identified barriers and facilitators could sustain large-scale ED-based alcohol screening programs and provide much needed support to patients who screen positive while reducing burden on EDs. The proposed study would be the first to develop and test this targeted implementation strategy and will prepare for a larger, fully powered hybrid effectiveness-implementation trial. Findings may also be broadly applicable to implementation of patient-facing mobile health technologies.Trial registrationThis study was registered at ClinicalTrials.gov (NCT05350878) on 4/28/2022.

Using waste to supply steam for industry transition: Selection of target industries through economic evaluation and statistical analysis

AbstractGlobal warming mitigation requires worldwide action in a wide range of fields, including waste treatment and management. In Japan, demands to transform waste into energy as a greenhouse gas emissions reduction strategy are increasing. The use of steam generated from waste treatment plants as a source of energy in industries is a promising energy recovery method. In recent years, the feasibility and economic potential of conversion of waste into energy have been evaluated; however, economic efficiency is not always achieved. Therefore, it is necessary to classify steam supply targets based on profitability. Herein, we selected appropriate industries from different types and scales of industries for steam supply based on analyses carried out in Aichi Prefecture. Therefore, industries were classified based on their production shipment value. We also calculated the maximum profit potential from steam supply from waste treatment plants and the steam demand potential of each mesh. We applied data envelopment analysis (DEA) to evaluate energy efficiency and regression analysis to evaluate the potential effects on growth. The appropriate industry was estimated through decision tree analysis based on DEA scores for the mixed industries cluster. We extracted four appropriate industries: pulp, textiles, ceramics, and steel. For each industry, we calculated the number of firms required in the mesh for economic benefit. We also selected industries that could be used to explore the potential of adopting the developed methodology for other regions and industries and for identification of waste treatment plants that could participate in steam supply.

Composition of nekton and jellyfishes communities and the results of trawl survey for estimation of abundance of pre-anadromous migrations pink salmon (&lt;i&gt;Oncorhynchus gorbuscha&lt;/i&gt;) in the north-western Pacific Ocean in summer 2021

As a result, of a trawl survey performed in the Pacific waters of the Kuril Islands within the EEZ of the Russian Federation and outside the external border of the EEZ of the Russian Federation, the abundance and biomass of all representatives of nekton and macroplankton were determined. Peculiarities of the spatial distribution of massive representatives of pelagic nekton and jellyfish were revealed. According to the summer survey of the upper epipelagic layer of the Pacific waters, the abundance and biomass of Pacific salmon during their pre-anadromous migrations to the rivers of the Okhotsk Sea basin were taken into account and the main concentrations of mature pink salmon were outlined. During the survey, data on the biological state of salmon in mixed clusters were obtained and preliminary spatial differentiation of the early and late pink salmon stock belonging to different regions of the Okhotsk Sea was performed.

Understanding of the Photodetachment Spectrum of Anionic Mixed Carbon-Boron Cluster C3B5- Following Adiabatic and Nonadiabatic Quantum Chemistry Approaches.

The presence of nonadiabaticity in the photodetachment bands of the anionic mixed carbon-boron cluster C3B5- has been realized through ab initio electronic structure calculations and detailed analyses of quantum dynamics study on top of those electronic structures. In the course of our study, we traverse extensive first principles electronic structure calculations to compute potential energy curves and to trace the energetic locations for the conical intersections in the multidimensional surfaces. All the ab initio calculations are performed on the four low-lying electronic states of the C3B5 cluster, while quantum nuclear dynamics are pursued on those electronic states by applying both time-dependent and time-independent quantum chemistry frameworks. In particular, we rely on the diabatic electronic representation to construct the molecular Hamiltonian. Altogether, the simulated theoretical spectra offer exceptional agreement with the experimental attainments.

Hydrophobic Cluster Formation in Aqueous Ethanol Solutions Probed by Soft X-ray Absorption Spectroscopy.

Hydrophobic cluster structures in aqueous ethanol solutions at different concentrations have been investigated by soft X-ray absorption spectroscopy (XAS). In the O K-edge XAS, we have found that hydrogen bond structures among water molecules are enhanced in the middle-concentration region by the hydrophobic interaction of the ethyl groups in ethanol. In the C K-edge XAS, the lower energy features arise from a transition from the terminal methyl C 1s electron to an unoccupied orbital of 3s Rydberg character, which is sensitive to the nearest-neighbor intermolecular interactions. From the comparison of C K-edge XAS with the inner-shell calculations, we have found that ethanol clusters are easily formed in the middle-concentration region due to the hydrophobic interaction of the ethyl group in ethanol, resulting in the enhancement of the hydrogen bond structures among water molecules. This behavior is different from aqueous methanol solutions, where the methanol-water mixed clusters are more predominant in the middle-concentration region due to the relatively weak hydrophobic interactions of the methyl group in methanol.

Chosa herring – the unclaimed resource of the Arctic

The study and development of the stock of Chosa herring (Clupea pallasii suworovi) last about 100 years. In the 1940s and 60s, it was one of the main objects of coastal fishing in the Mezen Bay and the Czech Bay with a result of up to 830 tons/year. In the 1970s and 1990s, intensive marine fishing was conducted in the Barents Sea with maximum catches of over 4 thousand tons/year. In 1978–2017, the stock was estimated in the range of 1,5–50 thousand tons, higher estimates relate to mixed clusters of multi-vertebral and low-vertebral herring. The current state of the stock is consistently good, at the level of 25–27 thousand, but fishing is conducted by local residents exclusively for personal consumption. As an object of specialized fishing, the Chosa herring remains unclaimed.

Silver Ion-Induced Formation of Unprecedented Thorium Nonamer Clusters via Lacuna-Construction Strategy

Silver Ion-Induced Formation of Unprecedented Thorium Nonamer Clusters via Lacuna-Construction Strategy

Incorporating Fe-O cluster in multivariate (MTV) metal–organic frameworks for promoting visible-light photo-Fenton degradation of micropollutants from water

Exploring efficient heterogeneous photo-Fenton catalysis is crucial for advanced water purification. In this study, a series of multivariate (MTV) metal–organic framework MIL-100 (Sc 0.98, 0.95, 0.87, 0.75, 0.58, Fe 0.02, 0.05, 0.13, 0.25 0.42) catalysts with increasing Fe contents were synthesized to effectively degrade micropollutants. By incorporating the Fe-O cluster into the framework, the degradation rate of sulfamethylthiazole (SMX) was improved 11.85 times over the MTV MIL-100 (Sc 0.58, Fe 0.42). The permanent porous structures and high surface areas (1597 m2/g ∼ 1389 m2/g) facilitated the adsorption processes. Results show that the initial adsorption rates for quinolone and anti-inflammatory groups were extremely high, with v0 = 463.16 ∼ 407.15 μg/g min. The modified material enhanced the visible-light absorption and facilitated the formation of reactive oxygen species (•OH, 1O2, and O2•−) under the irradiation of solar light. Electron paramagnetic resonance trapping technologies and quenching experiments were applied. The pathway for ROS formation under solar-light irradiation was proposed in detail. Aromatic intermediates were identified and quantitatively analyzed using UPLC-Q-TOF-MS. We believe that this strategy of incorporating mixed metal clusters in MOFs offers useful guidance to improve the performance of current materials.

The interferon-β/STAT1 axis drives the collective invasion of skin squamous cell carcinoma with sealed intercellular spaces

The process by which cancer cells invade as a cell cluster, known as collective invasion, is associated with metastasis and worse prognosis of cancer patients; therefore, inhibition of collective invasion is considered to improve cancer treatment. However, the cellular characteristics responsible for collective invasion remain largely unknown. Here, we successfully established subclones with various invasive potentials derived from human skin squamous carcinoma cells. The cell cluster of the highly invasive subclone had a hermetically sealed and narrow intercellular space. Interferon-β was localized to the sealed intercellular spaces, leading to collective invasion via the activation of signal transducer and activator of transcription 1 (STAT1). On the other hand, interferon-β was not localized to non-sealed and wide intercellular spaces of the cell cluster of low-invasive subclone with deficient STAT1 activity. In the mixed cell cluster of high- and low-invasive subclones, the high-invasive sub-clonal cells were located at the invasive front of the invasive protrusion, leading to collective invasion by the low-invasive sub-clonal cells. Tissue microarray analysis of human skin squamous cell carcinoma (SCC) also showed enrichment of STAT1 in the invasive front of SCCs. These findings indicate that the intercellular structure controls the potential for collective invasion via STAT1 regulation in SCC.

The Evolution of Geometric Structures, Electronic Properties, and Chemical Bonding of Small Phosphorus-Boron Clusters

We report a comprehensive theoretical investigation on phosphorus–boron mixed neutral, anionic, and cationic clusters P2Bn/P2Bn−/P2Bn+ (n = 3–7) with two phosphorus atoms and three to seven boron atoms. We reveal the common character of all the structures (i.e., the phosphorus atoms choose to occupy the peripheral position), whereas the boron atoms tend to be in the central and inside position of the ground state phosphorus—boron mixed clusters at each stoichiometry. Any three atoms preferentially form a stable triangle and grow with zigzag shape in a planar network. Interestingly, a series of planar motifs (including tetra-, penta-, and hexa-coordination) have been discovered in the phosphorus–boron clusters. The large binding energies (3.6 to 4.6 eV/atom) and quite large HOMO–LUMO gaps (5 to 10 eV) indicate the high stability of the clusters. The energy differences Δ1E, Δ2E, and energy gaps display oscillating behavior with increasing numbers of boron atoms. The electron affinity (EA) and ionization potential (IP) generally have small variations, with the EA values ranging from 2 to 3 eV, and the IP values ranging from 7 to 9 eV. Chemical bond analysis shows that the existence of multi-center delocalized bonds stabilize the clusters.