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1.
Montecchi M. Nichelatti E. Montereali R.M. Piccinini M. Somma F. 《Optical and Quantum Electronics》2004,36(1-3):43-56
An analytical expression of the complex permittivity is derived for absorbing centres featuring inhomogeneous absorption-line broadening. Such an expression gives the dispersion law of the real part of the permittivity when the imaginary part has a Gaussian lineshape. Our mathematical approach starts from an overlap integral of Lorentzian-type dielectric susceptibilities weighted by a Gaussian probability distribution of the resonance absorption energies. The analytical solution found is consistent with the Kramers–Kronig relation. We demonstrate that, like in the case of homogeneous absorption-line broadening, the refractive index increases at photon energies lower than the resonance absorption energy also for inhomogeneous absorption-line broadening; if the absorbing centres emit Stokes-shifted radiation, such an increase can be exploited for passive and active waveguiding applications. An example is reported regarding active waveguides based on colour centres in a lithium fluoride crystal. 相似文献
2.
ABSTRACT Copolymers of 1,5-dioxepan-2-one (DXO) and e-caprolactone (?-CL), δ-valerolactone (δ-VL) or L-lactide (LLA) have been synthesized and characterized. High molecular weight copolymers were obtained using stannous-2-ethyl hexanoate as catalyst in bulk. Reactivity ratios for the copolymerization of DXO and δ-VL were determined at 110°C as rVL=0.5 and rDXO=2.3. At high conversion, depolymerization of δ-VL occurred, resulting in lower molecular weight and variations in the copolymer composition. Physical properties, such as crystallinity and melting temperature of the DXO-copolymers proved to be strongly dependent on the choice of comonomer and on the molar composition of the copolymers. DXO appears to be incorporated into the poly-?-caprolactone (PCL) crystals and to some extent into the poly-δ-valerolactone (PVL) crystals, resulting in a more gradual decrease in crystallinity with increasing amount of DXO. 相似文献
3.
Ricardo G. Alvim Petrina Georgala Lucas Nogueira Alexander J. Somma Karan Nagar Jasmine Thomas Laura Alvim Amelia Riegel Christopher Hughes Jie Chen Augusto B. Reis Souhil Lebdai Avigdor Scherz Steven Zanganeh Rui Gardner Kwanghee Kim Jonathan A. Coleman 《Molecules (Basel, Switzerland)》2021,26(12)
Purpose: Vascular targeted photodynamic therapy (VTP) is a nonsurgical tumor ablation approach used to treat early-stage prostate cancer and may also be effective for upper tract urothelial cancer (UTUC) based on preclinical data. Toward increasing response rates to VTP, we evaluated its efficacy in combination with concurrent PD-1 inhibitor/OX40 agonist immunotherapy in a urothelial tumor-bearing model. Experimental design: In mice allografted with MB-49 UTUC cells, we compared the effects of combined VTP with PD-1 inhibitor/OX40 agonist with those of the component treatments on tumor growth, survival, lung metastasis, and antitumor immune responses. Results: The combination of VTP with both PD-1 inhibitor and OX40 agonist inhibited tumor growth and prolonged survival to a greater degree than VTP with either immunotherapeutic individually. These effects result from increased tumor infiltration and intratumoral proliferation of cytotoxic and helper T cells, depletion of Treg cells, and suppression of myeloid-derived suppressor cells. Conclusions: Our findings suggest that VTP synergizes with PD-1 blockade and OX40 agonist to promote strong antitumor immune responses, yielding therapeutic efficacy in an animal model of urothelial cancer. 相似文献
4.
5.
Somma A Ferranti P Addeo F Mauriello R Chianese L 《Journal of chromatography. A》2008,1192(2):294-300
The main peptides produced by hydrolysis of water buffalo beta-casein with plasmin were characterized by capillary electrophoresis and mass spectrometry and compared with their bovine homologous. A novel breakdown product arising from the hydrolysis of water buffalo beta-casein, originated by the presence of a plasmin-sensitive Lys bond at position 68 was identified, which was not present in bovine beta-casein. On the basis of this evidence, an improved procedure for the detection and the differentiation of the products of plasmin hydrolysis of bovine and water buffalo beta-casein by capillary isoelectric focusing was set-up. In the experimental conditions, the gamma-casein from the two species was efficiently separated. Comparison of the capillary electropherograms with those obtained by ultra-thin-layer isoelectric focusing, the reference method for routine analysis of plasmin digests of casein, suggests that capillary electrophoresis isoelectric focusing may constitute a successful alternative to the traditional slab gel electrophoresis analysis of plasmin digests of casein either for basic structural studies or for applications in the quality assessment of dairy products. 相似文献
6.
RD Harris WS Baker Van Stipdonk MJ RM Crooks EA Schweikert 《Rapid communications in mass spectrometry : RCM》1999,13(14):1374-1380
A suite of keV polyatomic or 'cluster' projectiles was used to bombard unoxidized and oxidized self-assembled monolayer surfaces. Negative secondary ion yields, collected at the limit of single ion impacts, were measured and compared for both molecular and fragment ions. In contrast to targets that are orders of magnitude thicker than the penetration range of the primary ions, secondary ion yields from polyatomic projectile impacts on self-assembled monolayers show little to no enhancement when compared with monatomic projectiles at the same velocity. This unusual trend is most likely due to the structural arrangement and bonding characteristics of the monolayer molecules with the Au(111). Copyright 1999 John Wiley & Sons, Ltd. 相似文献
7.
Giovanna Gomez dAyala Emilia Di Pace Paola Laurienzo Diletta Pantalena Elvira Somma Maria Rossella Nobile 《European Polymer Journal》2009,45(11):3217-3229
Functionalization of polymers is a particular relevant approach in the field of biodegradable polymers, where modifications are often required to allow these materials to replace more conventional, not biodegradable polymers in a wider range of applications. This article will report on functionalization of poly(ε-caprolactone) with unsaturated monomers bearing either anhydride groups (PCL-g-(MA-GMA)) or tertiary amines (PCL-g-DMAEA), obtained through radical grafting in a Brabender mixer. Crystallization kinetics parameters have been determined with several techniques (rheology, optical microscopy and differential scanning calorimetry) and the results obtained are in good agreement. It was observed that the crystallization rate significantly increases in the case of the modified polymers. 相似文献
8.
Rossana Iervolino Elvira Somma Maria Rossella Nobile Xuming Chen Benjamin S. Hsiao 《Journal of Thermal Analysis and Calorimetry》2009,98(3):611-622
The flow-induced crystallization behavior of nanocomposites, containing isotactic poly(1-butene) (PB) and functionalized multi-walled
carbon nanotubes (MWNT), was investigated. Three different MWNT concentrations (0.1, 1, 5 wt%) were used to prepare the nanocomposites.
Effects of MWNT and shear flow on the crystallization parameters were evaluated separately. Rheological measurements based
on oscillatory shear revealed induction time and crystallization half-time at the quiescent state, where both parameters exhibited
the nucleating effect of MWNT on PB. Rheological measurements based on steady-state shear flow and short-time shear flow revealed
the evolution of molecular orientation, which was studied in both PB and its nanocomposites. A small increase in crystallization
kinetic was recorded in PB under shear having moderate values of the Weissenberg (We) number. On the other hand, a dramatic synergistic effect of MWNT and shear was detected under the same shear conditions
for nanocomposites. The optical microscopic images exhibited a clear transition from isotropic to row-like morphology in the
case of nanocomposites under shear. 相似文献
9.
A Mukherjee M Dasgupta DJ Hinde CR Morton AC Berriman RD Butt JO Newton H Timmers 《Pramana》2001,57(1):195-198
Fusion cross-sections for the 7Li + 12C reaction have been measured at energies above the Coulomb barrier by the direct detection of evaporation residues. The heavy
evaporation residues with energies below 3 MeV could not be separated out from the α-particles in the spectrum and hence their
contribution was estimated using statistical model calculations. The present work indicates that suppression of fusion cross-sections
due to the breakup of 7Li may not be significant for 7Li + 12C reaction at energies around the barrier. 相似文献
10.
G. Baldacchini E. Giovenale F. De Matteis A. Scacco F. Somma U. M. Grassano 《Il Nuovo Cimento D》1988,10(6):693-708
Summary The lineshapes of the absorption bands ofF
A
centres in alkali halides have been studied for the first time. The new method used for this investigation is based on the
determination of the overlap between theF
A1
andF
A2
bands from luminescence measurements. The experimental results have been compared with calculated values deduced from the
theoreticalF
A
bands of different shapes. For bothF
A
(I) centres in KCl: Na+ andF
A
(II) centres in KCl: Li+ and RbCl: Li+ the absorption lineshape at low temperature is much closer to a sum of two Lorentzian curves than that of two Gaussian or
Poissonian bands. This result shows an unexpected difference with theF centres, whose absorption lineshape is known to be Poissonian at the same temperatures.
Riassunto Sono state studiate per la prima volta le forme di riga delle bande di assorbimento dei centriF A in alogenuri alcalini. Il nuovo metodo usato per questa indagine è basato sulla determinazione attraverso misure di luminescenza della sovrapposizione fra le bandeF A1 eF A2 . I risultati sperimentali sono stati confrontati con i valori dedotti da bandeF A teoriche di diverse forme. La forma di riga dell'assorbimento a bassa temperatura, sia per i centriF A (I) in KCl: Na+ sia per i centriF A (II) in KCl: Li+ e RbCl: Li+, è approssimata molto meglio da una somma di due curve Lorentziane che da quella di due bande Gaussiane o Poissoniane. Questo risultato rivela una differenza imprevista rispetto ai centriF, il cui assorbimento ha una forma di riga Poissoniana alle stesse temperature.
Резюме Впервые исследуются формы линий зон поглощения дляF A центров в щелочно-галоидных соединениях. Предлагается новый метод исследования. Этот метод основан на определении перекрытия междуF A иF A2 зонами из измерений люминесценции. Экспериментальные результаты сравниваются с вычисленными величинами, полученными из теоретическихF A зон различной формы. ДляF A (I) центров в KCl: Na+ иF A (II) центров в KCl: Li+ и RbCl: Li+ форма линии поглощения при низких температурах оказывается ближе к сумме двух Лоренцевых кривых, а не двух Гауссовых или Пуассоновых зон. Этот результат обнаруживает неожиданное отличие отF центров, форма линии поглощения которых, как известно, представляет Пуассонову кривую при тех же температурах.相似文献