81 research outputs found
Quasi-degenerate self-trapping in one-dimensional charge transfer exciton
The self-trapping by the nondiagonal particle-phonon interaction between two
quasi-degenerate energy levels of excitonic system, is studied. We propose this
is realized in charge transfer exciton, where the directions of the
polarization give the quasi-degeneracy. It is shown that this mechanism, unlike
the conventional diagonal one, allows a coexistence and resonance of the free
and self-trapped states even in one-dimensional systems and a quantitative
theory for the optical properties (light absorption and time-resolved
luminescence) of the resonating states is presented. This theory gives a
consistent resolution for the long-standing puzzles in quasi-one-dimensional
compound A-PMDA.Comment: accepted to Phys. Rev. Letter
Phenotypic and Genotypic Characterization and Treatment of a Cohort with Familial Tumoral Calcinosis/Hyperostosis-Hyperphosphatemia Syndrome
Familial tumoral calcinosis (FTC)/hyperostosis-hyperphosphatemia syndrome (HHS) is a rare disorder caused by mutations in the genes encoding fibroblast growth factor-23 (FGF23), N-acetylgalactosaminyltransferase 3 (GALNT3), or KLOTHO. The result is functional deficiency of, or resistance to, intact FGF23 (iFGF23), causing hyperphosphatemia, increased renal tubular reabsorption of phosphorus (TRP), elevated or inappropriately normal 1,25-dihydroxyvitamin D3 (1,25D), ectopic calcifications and/or diaphyseal hyperostosis. Eight subjects with FTC/HHS were studied and treated. Clinical manifestations varied, even within families, ranging from asymptomatic to large, disabling calcifications. All subjects had hyperphosphatemia, increased TRP, and elevated or inappropriately normal 1,25D. C-terminal FGF23 was markedly elevated while iFGF23 was comparatively low, consistent with increased FGF23 cleavage. Radiographs ranged from diaphyseal hyperostosis to massive calcification. Two subjects with severe calcifications also had overwhelming systemic inflammation and elevated C-reactive protein (CRP). GALNT3 mutations were identified in 7 subjects; no causative mutation was found in the eighth. Biopsies from 4 subjects showed ectopic calcification and chronic inflammation, with areas of heterotopic ossification observed in 1 subject. Treatment with low phosphate diet, phosphate binders, and phosphaturia-inducing therapies was prescribed with variable response. One subject experienced complete resolution of a calcific mass after 13 months of medical treatment. In the 2 subjects with systemic inflammation, interleukin-1 (IL-1) antagonists significantly decreased CRP levels with resolution of calcinosis cutis and peri-lesional inflammation in one subject and improvement of overall well-being in both subjects. This cohort expands the phenotype and genotype of FTC/HHS and demonstrates the range of clinical manifestations despite similar biochemical profiles and genetic mutations. Overwhelming systemic inflammation has not been described previously in FTC/HHS; the response to IL-1 antagonists suggests that anti-inflammatory drugs may be useful adjuvants. In addition, this is the first description of heterotopic ossification reported in FTC/HHS, possibly mediated by the adjacent inflammation
Thermal Behavior of Benzoic Acid/Isonicotinamide Binary Cocrystals
YesA comprehensive study of the thermal behavior of the 1:1 and 2:1 benzoic acid/isonicotinamide cocrystals is reported. The 1:1 material shows a simple unit cell expansion followed by melting upon heating. The 2:1 crystal exhibits more complex behavior. Its unit cell first expands upon heating, as a result of C–H···π interactions being lengthened. It then is converted into the 1:1 crystal, as demonstrated by significant changes in its X-ray diffraction pattern. The loss of 1 equiv of benzoic acid is confirmed by thermogravimetric analysis–mass spectrometry. Hot stage microscopy confirms that, as intuitively expected, the transformation begins at the crystal surface. The temperature at which conversion occurs is highly dependent on the sample mass and geometry, being reduced when the sample is under a gas flow or has a greater exposed surface area but increased when the heating rate is elevated
Absorption, Photoluminescence, and Polarized Raman Spectra of a Fourfold Alkoxy-Substituted Phthalocyanine Liquid Crystal
Investigation on the laser ablation of SiC ceramics using micro‐Raman mapping technique
Diffusion Monte Carlo Study of Para -Diiodobenzene Polymorphism Revisited
We revisit our investigation of the diffusion Monte Carlo (DMC) simulation of p-DIB molecular crystal polymorphism. [J. Phys. Chem. Lett. 2010, 1, 1789-1794] We perform, for the first time, a rigorous study of finite-size effects and choice of nodal surface on the prediction of polymorph stability in molecular crystals using fixed-node DMC. Our calculations are the largest which are currently feasible using the resources of the K computer and provide insights into the formidable challenge of predicting such properties from first principles. In particular, we show that finite-size effects can influence the trial nodal surface of a small (1×1×1) simulation cell considerably. We therefore repeated our DMC simulations with a 1×3×3 simulation cell, which is the largest such calculation to date. We used a DFT nodal surface generated with the PBE functional and we accumulated statistical samples with ∼6.4×105 core-hours for each polymorph. Our final results predict a polymorph stability consistent with experiment, but indicate that results in our previous paper were somewhat fortuitous. We analyze the finite-size errors using model periodic Coulomb (MPC) interactions and kinetic energy corrections, according to the CCMH scheme of Chiesa, Ceperley, Martin, and Holzmann. We investigate the dependence of the finite-size errors on different aspect ratios of the simulation cell (k-mesh convergence) in order to understand how to choose an appropriate ratio for the DMC calculations. Even in the most expensive simulations currently possible, we show that the finite size errors in the DMC total energies are far larger than the energy difference between the two polymorphs, although error cancellation means that the polymorph prediction is accurate. Finally, we found that the T-move scheme is essential for these massive DMC simulations in order to circumvent population explosions and large time-step biases.Chemistry and Chemical Biolog
RIQUALIFICAZIONE DEL CENTRO STORICO DI GRAGNANO E PIANO DEL COLORE MEDIANTE GIS
In tutti i fenomeni legati al territorio non si può fare a meno dell’uso di nuove
tecniche informatiche ed in particolare dei GIS, strumento ormai indispensabile
che permette di risolvere complessi problemi di analisi spaziale. La costruzione di
un GIS avviene attraverso un processo che parte con la raccolta delle informazioni
e finisce con la presentazione dei risultati.
Il nostro lavoro segue le linee guida della legge regionale N26/2002 “Norme ed
incentivi per la valorizzazione dei centri storici della Campania e per la
catalogazione dei Beni Ambientali di qualità paesistica. Modifiche alla Legge
Regionale 19 febbraio 1996, n.3”, in particolare i lavori di catalogazione e
progetto del colore del comune di Gragnano.
Dopo un accurato studio sulla storia del comune, di indagini sul campo,
stratigrafiche ed iconografiche, e rilievo delle cortine edilizie di una parte del
centro storico, si è proceduto alla catalogazione dell’intero edificato storico ed alla
creazione della “tavola dei colori storici” della città nonché al progetto del colore
di Via Roma, con l’ausilio della tecnologia GIS come base di lavoro. Dopo di ciò
è stato affrontato un lavoro di riqualificazione di Via Roma il cui principio guida è
la pedonalizzazione totale della strada e contemporaneamente la creazione di una
nuova arteria che la potesse sostituire. Per ovviare ai problemi di traffico che
saranno causati dall’interruzione carrabile del tratto, che è una delle arterie
principali della città, si propone la creazione di una nuova strada che prenderà il
posto della vecchia ferrovia ormai in disuso, per cui è stato fatto uno studio
preliminare in GIS dove sarà ampiamente dimostrato che la strada assorbirà
pienamente la quantità di traffico presente in zona.
Infine si è proceduto alla riqualificazione di uno spazio presente a Via Roma
occupato da un edificio crollato dopo il terremoto del novembre 1980.
L’intervento si inserisce senza stravolgere il contesto in cui si trova e vuole essere
un punto di aggregazione e di conoscenza per coloro che lo visitano
Cleaner production with lean thinking: An application to the fish canning industry of the Philippines
Philippine fish canning industry is responsible for several ill environmental impacts due to wastes from the whole production process, ranging from its inputs and high water consumption up to its high level of effluent wastewater discharge. The application of cleaner production and lean manufacturing had been explored for the first time in an industry setting to assuage its environmental impacts in order to bring the industry to the same decent levels as worldwide eco-friendly industries having new cleaner technologies. With this, an industry-wide survey dissemination was done to access the current system architecture of the fish canning companies in terms of their current environmental practices and lean tools used but only 17% of these companies agreed to participate in the survey. By conducting a case study, the cleaner production assessment identified the overall and per operation waste in the fish canning process where material balances showed six main waste streams namely spoiled fish, melted ice, damaged can, energy/heat loss, spilled sauces, and contaminated water. A comprehensive set of cleaner production options, gathered from related literature and focus group discussions, were proposed to eliminate the waste streams on receiving, at its source. To solve the production waste vis-a-vis the problem of decreasing raw fish supply and increasing tin can prices, a lean thinking approach was also conducted where overproduction, high inventories waiting and transport times are the non-value adding tasks shown in the current value stream map. To solve the production waste, inventory and demand level management, cellular manufacturing layout, work standardization, load-leveling, and 5s process were the lean tools and methodologies conformed to meet the proposed future state map.
The proposed cleaner production technologies and lean manufacturing tools were then integrated in the system architecture of the plant where overlapping solutions are evaluated lean-clean analysis heuristics. From the whole study, there is evidence to show that implementation of clean and lean technologies will reduce the environmental impact in the fish canning industries and the study estimate showed that water consumption decreased to 3 m³ /MT, BOD… effluence reduced to 9 kg/MT and energy consumption was continuously improved
Nonlinear oscillations of compact stars in the vicinity of the maximum mass configuration
Stability and degradation of fibroblast growth factor 23 (FGF23): the effect of time and temperature and assay type
There is growing need for a reliable assay for measuring fibroblast growth factor 23 (FGF23), a regulator of phosphorus and vitamin D. In this work, we analyze and compare the performance of three available assays, including the effect of temperature and time. This knowledge will allow for better understanding of FGF23 in the future.
Intact and C-terminal FGF23 (iFGF23 and cFGF23) concentrations are important in the diagnosis of hypo- and hyperphosphatemic diseases. The effects of temperature, storage, and specimen handling on FGF23 levels are not well known. We investigated the effects of various factors on plasma and serum measurement of FGF23 using three different assays.
Serum and plasma FGF23 were measured using three commercially available ELISA assays-two measuring iFGF23 and one measuring cFGF23. Samples from subjects with known FGF23 disorders were stored at 4, 22, and 37 °C and analyzed at different intervals up to 48 hours (h). A subset of samples underwent repeated freeze-thaw cycles, and samples frozen at -80 °C for up to 60 months were reanalyzed. The effect of adding a furin convertase inhibitor on FGF23 degradation was investigated using samples stored at 37 °C for 48 h. Intact FGF23 levels were measured from plasma samples of four different groups to test the correlation of the two assays.
Plasma FGF23 levels were stable when stored at 4 and 22 °C for 48 h. Both plasma and serum FGF23 levels demonstrated relative stability after five freeze-thaw cycles. Long-term storage at -80 °C for 40 months induced some variability in FGF23 levels. The addition of a furin inhibitor did not affect FGF23 degradation. Intact FGF23 levels showed good correlation only at the upper limit of the assay range when comparing the two assays.
Sample type, handling, and choice of assay are factors that affect FGF23 levels and should be considered when measuring this hormone
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