Highly porous photoluminescent diazaborole-linked polymers: synthesis, characterization, and application to selective gas adsorption

The formation of boron–nitrogen (B–N) bonds has been widely explored for the synthesis of small molecules, oligomers, or linear polymers; however, its use in constructing porous organic frameworks remains very scarce. In this study, three highly porous diazaborole-linked polymers (DBLPs) have been synthesized by condensation reactions using 2,3,6,7,14,15-hexaaminotriptycene and aryl boronic acids. DBLPs are microporous and exhibit high Brunauer–Emmett–Teller surface area (730–986 m2 g−1) which enable their use in small gas storage and separation. At ambient pressure, the amorphous polymers show high CO2 (DBLP-4: 4.5 mmol g−1 at 273 K) and H2 (DBLP-3: 2.13 wt% at 77 K) uptake while their physicochemical nature leads to high CO2/N2 (35–42) and moderate CO2/CH4 (4.9–6.2) selectivity. The electronic impact of integrating diazaborole moieties into the backbone of these polymers was investigated for DBLP-4 which exhibits green emission with a broad peak ranging from 350 to 680 nm upon excitation with 340 nm in DMF without photobleaching. This study demonstrates the effectiveness of B–N formation in targeting highly porous frameworks with promising optical properties

Cogan’s Syndrome in a Jordanian patient: A case report

AbstractWe reported a Jordanian case of Cogan’s Syndrome (CS). A 22-year old male patient presented with interstitial keratitis. The patient was treated successfully with topical steroids but over the following months, he developed vertigo, sensorineural hearing loss (SNHL) and generalized vasculitis. This is the first reported case of CS in Jordanian population

Nonuniformity in Lattice Contraction of Bismuth Nanoclusters Heated Near Its Melting Point

The structural properties of bismuth nanoclusters were investigated with transmission high-energy electron diffraction from room temperature up to 525 ± 6 K. The Bi nanoclusters were fabricated by thermal evaporation at room temperature on transmission electron microscope grids coated with an ultrathin carbon film, followed by thermal and femtosecond laser annealing. The annealed sample had an average cluster size of ∼14 nm along the minor axis and ∼16 nm along the major axis. The Debye temperature of the annealed nanoclusters was found to be 53 ± 6 K along the [012] direction and 86 ± 9 K along the [110] direction. At T = 464 ± 6 K, the diffraction intensity started to deviate from Debye-Waller behavior due to increased lattice anharmonicity. The onset of the melting of the Bi nanoclusters was T ∼ 500 ± 6 K, as measured by the reduction of the nanocluster size through the formation of a liquid shell detected by the width of the diffraction rings. The thermal expansion coefficient of the Bi (012) and (110) planes is positive up to ∼ 499 11 K. However, the expansion coefficient of the Bi (012) planes showed a transition from a positive to a negative value that occurs over the temperature range Tc ∼ 499 ± 11 K to 511 ± 8 K. For the Bi (110) planes, the thermal expansion coefficient is positive up to their melting point, which is 525 ± 6 K. © 2011 American Institute of Physics. [doi:10.1063/1.3565028

Leiomyoma of the Round Ligament of the Uterus : Case report and review of literature

Smooth muscle tumours of the round ligament of the uterus are rare and can mimic an inguinal hernia. Preoperative diagnosis can be established by a computed tomography scan of the abdomen or an exploration of the inguinal canal. Surgical excision is the curative treatment

Reinforcement Design Algorithm For Concrete Shells

The absence of universally accepted solutions in the structural concrete codes for the design of reinforcement in shells gives rise to the problem of calculating the required reinforcement in these structures. The constant development of the computer s performance and storage capacity combined with the powerful numerical methods reveal the need for a standard procedure to design shells subjected to membrane and flexural forces. In this paper, the solution for the design of the required reinforcement in concrete shells is presented based on a complete iterative computational algorithm to design shell elements subjected to combined membrane forces and bending moments. In the design equations, the reinforcement will contribute to tension and the concrete compression struts parallel to the crack direction will contribute to compression. The reinforcement is assumed to have two orthogonal layers placed in the top and bottom surfaces with appropriate covers. Each reinforcement layer has reinforcing bars placed orthogonally. For the concrete compression struts, the stress is assumed to be uniformly distributed in the depth of Whitney s stress block. This design algorithm is achieved by developing a design code (DRCSH) based on a complete iterative computational algorithm. This program can be used as a stand-alone version, to determine the load carrying capacity of critical points in reinforced concrete panels, plates and shells; and to verify the design code on the element level, five experimental models are designed. The designed elements give calculated ultimate strengths from 7 to 18% higher than test results values, except one model, which confirms the adequacy of the design algorithm, and the developed design code

Calculations of the Temperature and Alloy Composition Effects on the Optical Properties of Alx Ga1-x Asy Sb1-y and Gax In1-x Asy Sb1-y in the Spectral Range 0.5-6 eV

A detailed analysis is presented on the temperature and alloy composition dependence of the optical properties of III-V alloys Alx Ga1-x Asy Sb1-y and Gax In1-x Asy Sb1-y in the energy range 0.5-6 eV. Expressions for the complex dielectric function are based on a semiempirical phenomenological model, which takes under consideration indirect and direct transitions below and above the fundamental absorption edge. Dielectric function and absorption coefficient calculations are in satisfactory agreement with available experimental data. Other dielectric related optical data, such as the refractive index, extinction, and reflection coefficients, can also be obtained from the model. © 2007 American Institute of Physics. (DOI: 10.1063/1.2751406

Ultrafast Time-Resolved Structural Changes of Thin-Film Ferromagnetic Metal Heated With Femtosecond Optical Pulses

As a classic ferromagnetic material, nickel has been an important research candidate used to study dynamics and interactions of electron, spin, and lattice degrees of freedom. In this study, we specifically chose a thick, 150 nm ferromagnetic nickel (111) single crystal rather than 10–20 nm thin crystals that are typically used in ultrafast studies, and we revealed both the ultrafast heating within the skin depth and the heat transfer from the surface (skin) layer to the bulk of the crystal. The lattice deformation after femtosecond laser excitation was investigated by means of 8.04 keV subpicosecond x-ray pulses, generated from a table-top laser-plasma based source. The temperature evolution of the electron, spin, and lattice was determined using a three temperature model. In addition to coherent phonon oscillations, the blast force and sonic waves, induced by the hot electron temperature gradient, were also observed by monitoring the lattice contractions during the first couple of picoseconds after laser irradiation. This study further revealed the tens of picoseconds time required for heating the hundred nanometer bulk of the Ni (111) single crystals

Cylindrical Magnetron Development for Nb₃sn Deposition via Magnetron Sputtering

Due to its better superconducting properties (critical temperature Tc~ 18.3 K, superheating field Hsh~ 400 mT), Nb3Sn is considered as a potential alternative to niobium (Tc~ 9.25 K, Hsh~ 200 mT) for superconducting radiofrequency (SRF) cavities for particle acceleration. Magnetron sputtering is an effective method to produce superconducting Nb3Sn films. We deposited superconducting Nb3Sn films on samples with magnetron sputtering using co-sputtering, sequential sputtering, and sputtering from a stoichiometric target. Nb3Sn films produced by magnetron sputtering in our previous experiments have achieved DC superconducting critical temperature up to 17.93 K and RF superconducting transition at 17.2 K. A magnetron sputtering system with two identical cylindrical cathodes that can be used to sputter Nb3Sn films on cavities has been designed and is under development now. We report on the design and the current progress on the development of the system

Pirfenidone and post-Covid-19 pulmonary fibrosis: invoked again for realistic goals

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGPirfenidone (PFN) is an anti-fbrotic drug with signifcant anti-infammatory property used for treatment of fbrotic conditions such as idiopathic pulmonary fbrosis (IPF). In the coronavirus disease 2019 (Covid-19) era, severe acute respiratory syndrome 2 (SARS-CoV-2) could initially lead to acute lung injury (ALI) and in severe cases may cause acute respiratory distress syndrome (ARDS) which is usually resolved with normal lung function. However, some cases of ALI and ARDS are progressed to the more severe critical stage of pulmonary fbrosis commonly named post-Covid-19 pulmonary fbrosis which needs an urgent address and proper management. Therefore, the objective of the present study was to highlight the potential role of PFN in the management of post-Covid-19 pulmonary fbrosis. The precise mechanism of post-Covid-19 pulmonary fbrosis is related to the activation of transforming growth factor beta (TGF-β1), which activates the release of extracellular proteins, fbroblast proliferation, fbroblast migration and myofbroblast conversion. PFN inhibits accumulation and recruitment of infammatory cells, fbroblast proliferation, deposition of extracellular matrix in response to TGFβ1 and other pro-infammatory cytokines. In addition, PFN suppresses furin (TGFβ1 convertase activator) a protein efector involved in the entry of SARS-CoV-2 and activation of TGFβ1, and thus PFN reduces the pathogenesis of SARS-CoV-2. Besides, PFN modulates signaling pathways such as Wingless/Int (Wnt/β-catenin), Yes-Associated Protein (YAP)/Transcription CoActivator PDZ Binding Motif (TAZ) and Hippo Signaling Pathways that are involved in the pathogenesis of post-Covid-19 pulmonary fbrosis. In conclusion, the anti-infammatory and anti-fbrotic properties of PFN may attenuate post-Covid-19 pulmonary fbrosis