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141.
G. Romeo und N. Sciacca 《Fresenius' Journal of Analytical Chemistry》1931,83(7-8):309
Ohne Zusammenfassung 相似文献
142.
In this paper, we consider an extension of the Markovitz model, in which the variance has been replaced with the Value-at-Risk. So a new portfolio optimization problem is formulated. We showed that the model leads to an NP-hard problem, but if the number of past observation T or the number of assets K are low, e.g. fixed to a constant, polynomial time algorithms exist. Furthermore, we showed that the problem can be formulated as an integer programming instance. When K and T are large and αVaR is small—as common in financial practice—the computational results show that the problem can be solved in a reasonable amount of time. 相似文献
143.
The kinetics of the reaction of O3 with the aromatic vicinal diols 1,2‐benzenediol, 3‐methyl‐1,2‐benzenediol, and 4‐methyl‐1,2‐benzenediol have been investigated using a relative rate technique. The rate coefficients were determined in a 1080‐L smog chamber at 298 K and 1 atm total pressure of synthetic air using propene and 1,3‐butadiene as reference compounds. The following O3 reaction rate coefficients (in units of cm3 molecule?1 s?1) have been obtained: k(1,2‐benzenediol) = (9.60 ± 1.12) × 10?18, k(3‐methyl‐1,2‐benzenediol) = (2.81 ± 0.23) × 10?17, k(4‐methyl‐1,2‐benzenediol) = (2.63 ± 0.34) × 10?17. Absolute measurements of the O3 rate coefficient have also been carried out by measuring the decay of the dihydroxy compound in an excess of O3. The results from these experiments are in good agreement with the relative determinations. Atmospheric implications are discussed. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 223–230, 2003 相似文献
144.
Francesca Munari Carlo G. Barracchia Cinzia Franchin Francesca Parolini Stefano Capaldi Alessandro Romeo Luigi Bubacco Michael Assfalg Giorgio Arrigoni Mariapina D'Onofrio 《Angewandte Chemie (International ed. in English)》2020,59(16):6607-6611
In the brain of individuals with Alzheimer's disease, the regulatory protein ubiquitin is found conjugated to different lysine residues of tau protein assembled into pathological paired helical filaments. To shed light on the hitherto unexplored ubiquitination‐linked conformational transitions of tau, the availability of in vitro ubiquitin conjugation methods is of primary importance. In our work, we focused on the four‐repeat domain of tau and assembled an enzymatic machinery formed by UBE1, Ubc13, and CHIP enzymes. The enzymatic reaction resulted in monoubiquitination at multiple sites, reminiscent of the ubiquitination pattern observed in vivo. We further exploited chemoselective disulfide coupling reactions to construct three tau regioisomers with site‐specific monoubiquitination. Protein aggregation experiments revealed that the multiple enzyme‐derived products were unable to convert into amyloid fibrils, while the semisynthetic conjugates exhibited diverse capability to form filaments. This study contributes novel insight into the effects of a key post‐translational modification on aberrant protein self‐assembly. 相似文献
145.
Persistent organic pollutants in edible fish: a human and environmental health problem 总被引:1,自引:0,他引:1
Simonetta Corsolini Nicoletta Ademollo Teresa Romeo Silvio Greco Silvano Focardi 《Microchemical Journal》2005,79(1-2):115
Many persistent organic pollutants (POPs) pose serious health hazards to both the environment and human. Among these, polychlorobiphenyls (PCBs) are probable human carcinogens and can also pose non-cancer health hazards to intellectual functions and the nervous, immune and reproductive systems. The risks and hazards associated with POP residues in tissues are a function of the dioxin-like compound toxicity and an individual's exposure. Fish consumption might become a serious problem because of bioaccumulation as revealed in many studies worldwide.We report data concerning the accumulation and pattern of hexachlorobenzene (HCB), p,p′-DDE and PCBs in edible tissues of commercial fish species (bluefin tuna Thunnus thynnus, swordfish Xiphias gladius, Atlantic mackerel Scomber scombrus) from Italian Seas and of the Antarctic toothfish Dissostichus mawsoni from the Ross Sea (Antarctica). The species analyzed are part of the human diet. 2,3,7,8-TCDD toxic equivalents (TEQs) and tolerable weekly intake (TWI) were also calculated to evaluate the toxic hazard for the population that include them in their diet.Gaschromatography revealed 0.16±0.24 and 0.4±0.2 ng/g wet wt of HCB in Antarctic toothfish and bluefin tuna, respectively. p,p′-DDE concentrations were 38±29 and 31±38 ng/g wet wt in swordfish and bluefin tuna muscle, respectively, and 0.66±0.57 ng/g wet wt in the Antarctic toothfish. PCBs showed higher concentrations and they were 89±82, 80±86 and 5.2±4.0 ng/g wet wt in the muscle of swordfish, bluefin tuna and Antarctic toothfish, respectively. In Mediterranean fish, the most abundant congeners were the most persistent PCB numbers 153, 138, 180, 118 and 170, which accounted for 51% and 47% of the total PCB residue in tuna fish and swordfish, respectively, and 18% in the Antarctic toothfish. TEQs were 1.97 and 4.65 pg/g wet wt in bluefin tuna muscle and gonads, respectively, and 0.11 pg/g wet wt in Antarctic toothfish. The TEQ weekly intake was calculated and values ranged 197–465 pgTEQ/week when consuming 100 g of Mediterranean fish and therefore lower than the recommended TWI. Those values were higher (788–1860 pgTEQ/week) than the recommended TWI, if 400 g of fish/week was consumed (with the exception of Antarctic fish). 相似文献
146.
Renato DalpozzoAntonio De Nino Loredana MaiuoloAntonio Procopio Monica NardiGiuseppe Bartoli Roberto Romeo 《Tetrahedron letters》2003,44(30):5621-5624
Cerium(III) triflate is a powerful catalyst for the acetylation of alcohols. The reaction works well for a large variety of simple and functionalized alcohols, without isomerisation of chiral centres. Changes of hydroxyl protective groups are possible in a one-pot procedure. The catalyst can be easily recycled. 相似文献
147.
Rizzi L Braschi M Colombo M Vaiana N Tibolla G Norata GD Catapano AL Romeo S Prosperi D 《Organic & biomolecular chemistry》2011,9(8):2899-2905
Amphiphilic bile acids linked through an oligoethylene glycol to a biotin moiety were synthesized and shown to create micellar structures in aqueous environment, interact with avidin and be efficiently incorporated into hepatocyte cells, suggesting their potential as a drug delivery system against liver diseases. 相似文献
148.
For 0<p<+∞ let hp be the harmonic Hardy space and let bp be the harmonic Bergman space of harmonic functions on the open unit disk U. Given 1?p<+∞, denote by ‖⋅bp‖ and ‖⋅hp‖ the norms in the spaces bp and hp, respectively. In this paper, we establish the harmonic hp-analogue of the known isoperimetric type inequality ‖fb2p‖?‖fhp‖, where f is an arbitrary holomorphic function in the classical Hardy space Hp. We prove that for arbitrary p>1, every function f∈hp satisfies the inequality
‖fb2p‖?ap‖fhp‖, 相似文献
149.
Romeo Meštrović 《Czechoslovak Mathematical Journal》2013,63(4):949-968
Let p > 3 be a prime, and let q p (2) = (2 p?1 ? 1)/p be the Fermat quotient of p to base 2. In this note we prove that $$\sum\limits_{k = 1}^{p - 1} {\frac{1}{{k \cdot {2^k}}}} \equiv {q_p}(2) - \frac{{p{q_p}{{(2)}^2}}}{2} + \frac{{{p^2}{q_p}{{(2)}^3}}}{3} - \frac{7}{{48}}{p^2}{B_{p - 3}}(\bmod {p^3})$$ , which is a generalization of a congruence due to Z.H. Sun. Our proof is based on certain combinatorial identities and congruences for some alternating harmonic sums. Combining the above congruence with two congruences by Z.H. Sun, we show that $${q_p}{(2)^3} \equiv - 3\sum\limits_{k = 1}^{p - 1} {\frac{{{2^k}}}{{{k^3}}}} + \frac{7}{{16}}\sum\limits_{k = 1}^{(p - 1)/2} {\frac{1}{{{k^3}}}} (\bmod p)$$ , which is just a result established by K. Dilcher and L. Skula. As another application, we obtain a congruence for the sum $\sum\limits_{k = 1}^{p - 1} {{1 \mathord{\left/ {\vphantom {1 {\left( {k^2 \cdot 2^k } \right)}}} \right. \kern-0em} {\left( {k^2 \cdot 2^k } \right)}}}$ modulo p 2 that also generalizes a related Sun’s congruence modulo p. 相似文献
150.
Roberta Citro Adele Naddeo Francesco Romeo 《The European physical journal. Special topics》2013,217(1):55-62
We study nonequilibrium properties of an atomic quantum dot (AQD) coupled to a Bose-Einstein condensate (BEC) within Keldysh-Green’s function formalism when the AQD level is varied harmonically in time. Nonequilibrium features in the AQD energy absorption spectrum are the side peaks that develop as an effect of photon absorption and emission. We show that atoms can be efficiently transferred from the BEC into the AQD for the parameter regime of current experiments with cold atoms. 相似文献