| 1. |
- Watts, Anna L., et al.
(författare)
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Dense matter with eXTP
- 2019
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Ingår i: Science China Physics, Mechanics & Astronomy. - : Science Press. - 1674-7348 .- 1869-1927. ; 62:2
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Forskningsöversikt (refereegranskat)abstract
- In this White Paper we present the potential of the Enhanced X-ray Timing and Polarimetry (eXTP) mission for determining the nature of dense matter; neutron star cores host an extreme density regime which cannot be replicated in a terrestrial laboratory. The tightest statistical constraints on the dense matter equation of state will come from pulse profile modelling of accretion-powered pulsars, burst oscillation sources, and rotation-powered pulsars. Additional constraints will derive from spin measurements, burst spectra, and properties of the accretion flows in the vicinity of the neutron star. Under development by an international Consortium led by the Institute of High Energy Physics of the Chinese Academy of Sciences, the eXTP mission is expected to be launched in the mid 2020s.
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| 2. |
- Elkinany, Sherif, et al.
(författare)
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Is Aortic Z-score an Appropriate Index of Beneficial Drug Effect in Clinical Trials in Aortic Aneurysm Disease?
- 2021
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Ingår i: American Journal of Cardiology. - : Elsevier BV. - 0002-9149. ; 143
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Tidskriftsartikel (refereegranskat)abstract
- Aortic Z-score (Z-score) is utilized in clinical trials to monitor the effect of medications on aortic dilation rate in Marfan (MFS) patients. Z-scores are reported in relation to body surface area and therefore are a function of height and weight. However, an information void exists regarding natural, non-pharmacological changes in Z-scores as children age. We had concerns that Z-score decrease attributed to “therapeutic” effects of investigational drugs for Marfan disease connective tissue diseases might simply reflect normal changes (“filling out” of body contour) as children age. This investigation studies natural changes with age in Z-score in normal and untreated MFS children, teasing out normal effects that might erroneously be attributed to drug benefit. (1) We first compared body mass index (BMI) and Z-scores (Boston Children's Hospital calculator) in 361 children with “normal” single echo exams in four age ranges (0 to 1, 5 to 7, 10 to 12, 15 to 18 years). Regression analysis revealed that aging itself decreases ascending Z-score, but not root Z-score, and that increase in BMI with aging underlies the decreased Z-scores. (2) Next, we examined Z-score findings in both “normal” and Marfan children (all pharmacologically untreated) as determined on sequential echo exams over time. Of 27 children without aortic disease with sequential echos, 19 (70%) showed a natural decrease in root Z-score and 24 (89%) showed a natural decrease in ascending Z- score, over time. Of 25 untreated MFS children with sequential echos, 12 (40%) showed a natural decrease in root Z-score and 10 (33%) showed a natural decrease in ascending Z-score. Thus, Z-score is over time affected by natural factors even in the absence of any aneurysmal pathology or medical intervention. Specifically, Z-score decreases spontaneously as a natural phenomenon as children age and with fill out their BMI. Untreated Marfan patients often showed a spontaneous decrease in Z-score. In clinical drug trials in aneurysm disease, decreasing Z-score has been interpreted as a sign of beneficial drug effect. These data put such conclusions into doubt.
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| 3. |
- Hao, Fuying, et al.
(författare)
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Design, crystal structures and enhanced frequency-upconverted lasing efficiencies of a new series of dyes from hybrid of inorganic polymers and organic chromophores
- 2009
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Ingår i: Journal of Materials Chemistry. - : RSC Publishing. - 0959-9428 .- 1364-5501. ; 19:48, s. 9163-9169
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Tidskriftsartikel (refereegranskat)abstract
- A new series of hybrid dyes, trans-4-(4′-N,N-dialkylaminostyryl)-N-methyl pyridinium [Cd(SCN)3−]n [alkyl = Me(1), Et(2), Pr(3) and n–Bu(4)] have been successfully synthesized from hybrids of inorganic polymers and organic chromophores. The structures of four new hybrid dyes were characterized by single-crystal X-ray diffraction first. The particular features of the hybrid dyes are (1) the inorganic anions form isolated polymeric one-dimensional zig-zag chains of [Cd(SCN)3−]n with an extended π-conjugation system within the polymeric –[M–S–C≡N]–M… chain and high polarizabilities; and (2) the organic cationic chromophores determine their optical properties. Experimental results revealed that the TPA cross-section values and overall energy conversion efficiencies of hybrid dyes with different alkyl pendant groups have obviously increased from 1 to 4, and in particular, have been substantially enhanced compared to their corresponding iodide analogues 1′–4′. Therefore, we speculate that such increases are attributable to arrangements of infinite anionic [Cd(SCN)3−]n chains and synergic effects with chromophore cations.
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| 4. |
- Ju, Minhua, et al.
(författare)
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Preparation of size-controllable monodispersed carbon@silica core-shell microspheres and hollow silica microspheres
- 2017
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Ingår i: Microporous and Mesoporous Materials. - : Elsevier. - 1387-1811 .- 1873-3093. ; 247, s. 75-85
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Tidskriftsartikel (refereegranskat)abstract
- Size-controllable monodispersed carbon@silica core-shell microspheres and hollow silica microspheres were prepared in a simple homemade T-type mixer by polymerization of furfuryl alcohol (FA) and hydrolysis of TEOS in H2SO4 water phase microdroplets to obtain polyfurfuryl alcohol (PFA)@silica microspheres, followed by carbonization and calcination. The FA and TEOS diffuse into the water phase from an oil phase. The flow rates of oil and water phase were 4 and 2 ml h−1, respectively. It was found that the concentration of FA has a more significant effect on the diameter of carbon@silica core-shell microspheres than TEOS due to the template effect of the PFA core. However, the diameter of the hollow silica microspheres was influenced by the concentration of TEOS more significantly. The obtained core-shell microspheres and hollow silica microspheres have large surface area of 555 and 769 m2 g−1, respectively. The hollow silica microspheres have both microporous and mesoporous structure, and the percentage of mesoporous volume was as high as 89%. In addition, based on the study results, a rational formation process of the carbon@silica core-shell microsphere and hollow silica microspheres was assumed.
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| 5. |
- Ju, Minhua, et al.
(författare)
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Two-Phase Diffusion Technique for the Preparation of Ultramacroporous/Mesoporous Silica Microspheres via Interface Hydrolysis, Diffusion, and Gelation of TEOS
- 2018
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 34:5, s. 2046-2056
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Tidskriftsartikel (refereegranskat)abstract
- Honeycombed hierarchical ultramacroporous/mesoporous silica microspheres were prepared via the hydrolysis of TEOS in the oil-water interface, with subsequent diffusion and gelation in the acidic water-phase microdroplets with the assistance of a simple homemade microdevice. The diffusion of furfuryl alcohol (FA) also happened at a relatively high rate during the hydrolysis and diffusion of TEOS. Therefore, plenty of FA will be inside of the water microdroplets and form a decent number of polyfurfuryl alcohol (PFA) microparticles, thereby obtaining honeycombed hierarchical porosity silica microspheres with abundant ultramacroporous cavities and mesopores after calcination. It was found that the concentration of FA, residence time, and reaction temperature have significant effects on the porosity and pore size due to the influence on the diffusion rate and amount of FA in water-phase microdroplets. The honeycombed silica microspheres have obvious microscopic visible ultramacroporous cavities with the submicrometer cavity diameter as high as 85% porosity based on the rough overall volume of microsphere. N2 adsorption-desorption isotherms show that the honeycombed hierarchical porosity silica microspheres have a high surface area of 602 m2 g-1, a mesopore volume of 0.77 cm3/g, and a mesopore porosity of 99.6% based on the total pore volume of N2 adsorption-desorption. On the basis of the experiment results, a rational formation process of the honeycombed hierarchical porosity silica microspheres was deduced.
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| 6. |
- Li, Shengli, et al.
(författare)
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Formation of a Novel Polymeric Cadmium(II) Complex Bridged by Sulfur and Thiocyanato Ions
- 2003
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Ingår i: Chemistry Letters. - : Chemical Society of Japan. - 0366-7022 .- 1348-0715. ; 32:8, s. 748-749
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Tidskriftsartikel (refereegranskat)abstract
- The title complex, {[N(CH3)4]2[Cd(SCN)2S]}n, was prepared by self-assembling from the reaction of a methanol/water (volume ratio, 1/1) solution containing cadmium(II) thiocyanate with equivalent amount of tetramethylammonium thiocyanate. The result of single X-ray determination for the complex reveals that a novel polymeric cadmium(II) complex bridged by sulfur and thiocyanato ions was obtained, which formed a two-dimensional (2D) structure.
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| 7. |
- Li, Zongbao, et al.
(författare)
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Upconversion Luminescence of Graphene Oxide through Hybrid Waveguide
- 2018
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Ingår i: The Journal of Physical Chemistry C. - : AMER CHEMICAL SOC. - 1932-7447 .- 1932-7455. ; 122:29, s. 16866-16871
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Tidskriftsartikel (refereegranskat)abstract
- Phonon-assisted upconversion is a promising way to generate short-wavelength emissions under excitation of long wavelength based on unique anti-Stokes luminescence properties. Graphene oxide nanosheets (GONs) exhibit excellent optical properties owing to quantum confinement and edge effects, which have driven research into fundamental principles and potential applications. Here, we experimentally demonstrate upconversion emission by exciting an easily fabricated GON hybrid waveguide (GHVV) with enhanced photothermal effects. The results reveal different origins of short-wavelength range and long-wavelength range in the upconversion spectra, whereas the emissive surface defects of GONs and GHW structure play significant roles in the behavior of photoluminescence. Introducing other upconversion materials to promote emission efficiency, the hybrid waveguide system might readily provide the possibility for the construction of upconversion fiber lasers and remote control of the upconversion luminescence.
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| 8. |
- Wu, Jie-Ying, et al.
(författare)
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Synthesis, photoluminescence and electrochemical properties of a series of carbazole-functionalized ligands and their silver(I) complexes
- 2007
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Ingår i: Inorganica Chimica Acta. - : Elsevier. - 0020-1693 .- 1873-3255. ; 360:6, s. 2083-2091
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Tidskriftsartikel (refereegranskat)abstract
- A series of carbazole-functionalized carboxylate ligands (N-carbazolylacetic acid (L1), 4-carbazol-9-yl-benzoic acid (L2), and 3-(4-carbazol-9-yl-phenyl)-acrylic acid (L3)) and their corresponding silver complexes were designed and synthesized and the structures were determined by single crystal X-ray diffractions. The silver atoms in the complexes are in tetrahedral geometry coordinated with two oxygen from carboxylic and two phosphorous atoms from triphenylphosphine. The complexes exhibit excellent electrochemical characters in solution and strong photoluminescence in the solid state. The emission wavelengths of the compounds can be tuned (from ultraviolet to visible region) by introducing of the second coordinating ligand triphenylphosphine and by elongation of the conjugation moieties.
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| 9. |
- Yang, Yupeng, et al.
(författare)
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Plasmon-Enhanced Fluorescence of Single Quantum Dots Immobilized in Optically Coupled Aluminum Nanoholes
- 2023
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Ingår i: The Journal of Physical Chemistry Letters. - : American Chemical Society (ACS). - 1948-7185. ; 14:9, s. 2339-2346
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Tidskriftsartikel (refereegranskat)abstract
- Fluorescence-based optical sensing techniques have continually been explored for single-molecule detection targeting myriad biomedical applications. Improving signal-to-noise ratio remains a prioritized effort to enable unambiguous detection at single-molecule level. Here, we report a systematic simulation-assisted optimization of plasmon-enhanced fluorescence of single quantum dots based on nanohole arrays in ultrathin aluminum films. The simulation is first calibrated by referring to the measured transmittance in nanohole arrays and subsequently used for guiding their design. With an optimized combination of nanohole diameter and depth, the variation of the square of simulated average volumetric electric field enhancement agrees excellently with that of experimental photoluminescence enhancement over a large range of nanohole periods. A maximum 5-fold photoluminescence enhancement is statistically achieved experimentally for the single quantum dots immobilized at the bottom of simulation-optimized nanoholes in comparison to those cast-deposited on bare glass substrate. Hence, boosting photoluminescence with optimized nanohole arrays holds promises for single-fluorophore-based biosensing.
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| 10. |
- Zhang, Qiong, et al.
(författare)
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A series of Zn(II) terpyridine complexes with enhanced two-photon-excited fluorescence for in vitro and in vivo bioimaging
- 2015
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Ingår i: Journal of materials chemistry. B. - : ROYAL SOC CHEMISTRY. - 2050-750X .- 2050-7518. ; 3:36, s. 7213-7221
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Tidskriftsartikel (refereegranskat)abstract
- It is still a challenge to obtain two-photon excited fluorescent bioimaging probes with intense emission, high photo-stability and low cytotoxicity. In the present work, four Zn(II)-coordinated complexes (1-4) constructed from two novel D-A and D-p-A ligands (L-1 and L-2) are investigated both experimentally and theoretically, aiming to explore efficient two-photon probes for bioimaging. Molecular geometry optimization used for theoretical calculations is achieved using the crystallographic data. Notably, the results indicate that complexes 1 and 2 display enhanced two-photon absorption (2PA) cross sections compared to their corresponding D-A ligand (L1). Furthermore, it was found that complex 1 has the advantages of moderate 2PA cross section in the near-infrared region, longer fluorescence lifetime, higher quantum yield, good biocompatibility and enhanced two-photon excited fluorescence. Therefore, complex 1 is evaluated as a bioimaging probe for in vitro imaging of HepG2 cells, in which it is observed under a two-photon scanning microscope that complex 1 exhibits effective co-staining with endoplasmic reticulum (ER) and nuclear membrane; as well as for in vivo imaging of zebrafish larva, in which it is observed that complex 1 exhibits specificity in the intestinal system.
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