Modifying the STM Tip for the ' Ultimate ' Imaging of the Si(111)-7×7 Surface and Metal-supported Molecules

We report on high-resolution STM measurements with modified probe tips. First, both the rest atoms and adatoms of a Si(111)-7×7 surface are observed simultaneously. The visibility of rest atoms is dependent upon the sample bias voltage (less than –0.7 V) and is enhanced by sharpening the tip, which is rationalized by first-principles calculations. Second, a tip with a perylene molecule adsorbed at its apex is used to discriminate the molecular states and the metal states of the underlying Ag(110) surface, which is attributable to a mismatch between the energy levels of the functionalized tip and the adsorbates on silver. Lastly, high-resolution images of iron phthalocyanine (FePc) and zinc phthalocyanine (ZnPc) molecules on Au(111) are obtained by using an O2-terminated tip, and the images reveal rich intramolecular features arising from molecular orbitals that are not observed when using clean metallic tips

Benzyl 2-ethyl­hexyl sulfoxide

The mol­ecule of the title compound, C15H24OS, shows S conformations for the S atom and the asymmetric C atom of the isooctyl group. The long axes of the mol­ecules are directed along the c axis. In the crystal structure, the mol­ecules are linked by weak inter­molecular bifurcated C—H⋯O hydrogen bonds

CYP3A Mediates an Unusual C(sp2)-C(sp3) Bond Cleavage via Ipso-Addition of Oxygen in Drug Metabolism

Mammalian cytochrome P450 drug-metabolizing enzymes rarely cleave carbon–carbon (C-C) bonds and the mechanisms of such cleavages are largely unknown. We identified two unusual cleavages of non-polar, unstrained C(sp2)-C(sp3) bonds in the FDA-approved tyrosine kinase inhibitor pexidartinib that are mediated by CYP3A4/5, the major human phase I drug metabolizing enzymes. Using a synthetic ketone, we rule out the Baeyer-Villiger oxidation mechanism that is commonly invoked to address P450-mediated C-C bond cleavages. Our studies in 18O2 and H218O enriched systems reveal two unusual distinct mechanisms of C-C bond cleavage: one bond is cleaved by CYP3A-mediated ipso-addition of oxygen to a C(sp2) site of N-protected pyridin-2-amines, and the other occurs by a pseudo-retro-aldol reaction after hydroxylation of a C(sp3) site. This is the first report of CYP3A-mediated C-C bond cleavage in drug metabolism via ipso-addition of oxygen mediated mechanism. CYP3A-mediated ipso-addition is also implicated in the regioselective C-C cleavages of several pexidartinib analogs. The regiospecificity of CYP3A-catalyzed oxygen ipso-addition under environmentally friendly conditions may be attractive and inspire biomimetic or P450-engineering methods to address the challenging task of C-C bond cleavages

Case Report: Clinicopathological Analysis of Minute Pulmonary Meningothelial-Like Nodules: Report of 7 Cases

ObjectiveTo investigate the clinical manifestations, radiologic features, pathological features, and immunophenotype of minute pulmonary meningothelial-like nodules (MPMNs).MethodThis is a retrospective observational study. We collected the clinical data of 7 cases of MPMNs, and performed comprehensive characterization using a combination of clinical, morphological, radiologic and immunohistochemical assessments.ResultsOf the 7 cases of MPMNs, 6 were female and 1 was male. The median age was 55 years. All MPMNs were multiple in lung with the size from 0,01 to 0,5cm. Chest CT examination showed ground-glass attenuation or solid nodules. Four cases were concomitant with carcinoma and/or pneumonia, and 3 cases occurred alone. Four of the 7 patients had no obvious symptoms; 3 patients had chest pain or cough or shortness of breath or hemoptysis. Multiple white nodules were found macroscopically, and the diseased cells grew along the alveolar septum, with relatively normal morphology, rich cytoplasm, unclear cell boundary, and uniform nucleus with delicate chromatin and without atypia; and the diseased cells showed nest or whorls distribution. EMA, PR, CD56 and vimentin were positive in all cases by immunohistochemistry.ConclusionsMPMNs are rare benign lesions in the lung, often multiple, usually less than 0.5cm in diameter, most of which have no obvious clinical symptoms. MPMNs are often found by chest CT, and occur independently or concomitant with other lesions. The positive immunohistochemical staining of EMA, PR, CD56, vimentin supports the diagnosis

Assessment of geothermal resource potential in Changbaishan utilizing high-precision gravity-based man-machine interactive inversion technology

As one of the clean energy sources, geothermal resources have no negative impact in changing the climate. However, the accurate assessment and precise identification of the potential geothermal resource is still complex and dynamic. In this paper, ~2,000 large-scale high-precision gravity survey points are conducted in the north of the Tianchi caldera, Changbaishan. Advanced data processing technologies can provide straightforward information on deep geothermal resources (Hot source, caprock, geothermal reservoir and geothermal migration pathway). Upwards continuation and the technologies decode two dome shaped low and gentle anomalies (−48 × 10−5 m/s2−65 m/s2) and a positive gravity gradient anomaly (0.4 × 10−7 m/s2−1.6 × 10−5 m/s2) in large-scale high-precision gravity planar. According to two point five dimensional man-machine interactive inversion technology and the research on petrophysical parameters, the density of the shied-forming basalts in the two orthogonal gravity sections is 2.58 g/cm3. The relatively intermediate to high density (2.60–2.75 g/cm3) represents geothermal reservoir, and low density (low to 2.58 g/cm3) is the geothermal migration pathway. In addition, large-scale high-precision gravity planar with a solution of about 1/50,000 indicate that the north of the Tianchi caldera exits the sedimentary basin and uplift mountain geothermal system

Root growth adaptation is mediated by PYLs ABA receptor-PP2A protein phosphatase complex

Plant root architecture dynamically adapts to various environmental conditions, such as salt‐containing soil. The phytohormone abscisic acid (ABA) is involved among others also in these developmental adaptations, but the underlying molecular mechanism remains elusive. Here, a novel branch of the ABA signaling pathway in Arabidopsis involving PYR/PYL/RCAR (abbreviated as PYLs) receptor‐protein phosphatase 2A (PP2A) complex that acts in parallel to the canonical PYLs‐protein phosphatase 2C (PP2C) mechanism is identified. The PYLs‐PP2A signaling modulates root gravitropism and lateral root formation through regulating phytohormone auxin transport. In optimal conditions, PYLs ABA receptor interacts with the catalytic subunits of PP2A, increasing their phosphatase activity and thus counteracting PINOID (PID) kinase‐mediated phosphorylation of PIN‐FORMED (PIN) auxin transporters. By contrast, in salt and osmotic stress conditions, ABA binds to PYLs, inhibiting the PP2A activity, which leads to increased PIN phosphorylation and consequently modulated directional auxin transport leading to adapted root architecture. This work reveals an adaptive mechanism that may flexibly adjust plant root growth to withstand saline and osmotic stresses. It occurs via the cross‐talk between the stress hormone ABA and the versatile developmental regulator auxin

Maskless Generation of Single Silicon Vacancy Arrays in Silicon Carbide by a Focused He+ Ion Beam

Precise generation of spin defects in solid-state systems is essential for nanostructure fluorescence enhancement. We investigated a method for creating single silicon vacancy defect arrays in silicon carbide using a helium-ion microscope. Maskless and targeted generation can be realized by precisely controlling the focused He+ ion beam with an implantation uncertainty of 60 nm. The generated silicon vacancies were identified by measuring the optically detected magnetic resonance spectrum and room temperature photoluminescence spectrum. We systematically studied the effects of the implantation ion dose on the generated silicon vacancies. After optimization, a conversion yield of ~ 6.95 % and a generation rate for a single silicon vacancy of ~ 35 % were realized. This work paves the way for the integration and engineering of color centers to photonic structures and the application of quantum sensing based on spin defects in silicon carbide

Графический дизайн как визуальный язык межкультурного взаимодействия

This article describes how visual graphics language as a sign system can be in contact with the audience, overcoming the language barrier. In terms of graphic design it can be available to transfer information, and even affect the viewer, causing artistic and emotional reflection.Эта статья о том, как визуальный язык графики в виде знаковой символики может входить в контакт со зрителем, преодолевая языковый барьер. На языке графического дизайна можно доступно передать информацию и даже воздействовать на зрителя, вызывая при этом художественно-эмоциональные образы

How fear emotion impacts collective motion in threat environment

Introduction: The emergence of collective behavior often depends on the adequate interaction of individuals through self-organization and the exchange of local information. When facing external threats, communication among individuals requires both rapid and effective information exchange to characterize sudden events. In this paper, we introduce the mechanism of emotions into the modeling of dynamics to study collective avoidance behavior in response to threats.Methods: A scenario involving a hidden dynamic threat is constructed to test the avoidance and survival capabilities of the collective when faced with a lack of effective information. By employing the activation and spread of emotion in modeling, the collective may self-organized and adeptly mitigate risks and enhance their own benefits.Results: Through adjustments to the intensity of emotional activation, spread, and decay, rich behaviors emerge. Relying on the regulation of emotion, the collective exhibits different response strategies and action patterns when facing threats, in which the optimal performance from the macroscopic level is expectable.Discussion: By analyzing these phenomena, it can enhance our understanding of the emotional states of collective in response to threats and the methods of controlling in intelligent collective motion