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Ab initio quantum chemical calculations were carried out on the main factor responsible for the formation of β-sheet structures in specific regions of proteins. Geometry optimization was performed at the Hartree-Fock level using a 3-21G** basis functional set. Total energies of α-helix and β-sheet structures were compared using several types of computational models. The computational models for the β-sheet structure were constructed by extracting a part of the protein from X-ray crystallographic data of HIV-1 or myosin, and the computational models for the α-helix structure were constructed by modifying the model for the β-sheet structure. The results of computations indicated that all helix-like structures were more stable than were the β-sheet structures under the condition of absence of any other molecules. On the other hand, all of the β-sheet structures became more stable than the helix-like structures when water molecules existed around them. This finding suggests that β-sheet structures are stabilized by the presence of water molecules and are primarily determined by local interaction among several neighboring residues.

Quantum chemical calculations have been performed to clarify the reason why the helix formation ends to convert to another secondary structure at the particular sites in a protein. In this study, we used the conversion regions from helix to another structure seen in HIV-1 protease, Calmodulin-dependent protein kinase, and 8-oxoguanine glycosylase. Three-dimensional structures of these proteins had already been determined by X-ray crystallographic analysis, and model molecules representing the conversion region were constructed using sequential 5 or 6 amino-acid residues. Schrodinger equations for the model molecules were solved using ab initio molecular orbital (MO) method in the Hartree–Fock level. We also constructed model molecules representing a hypothetical situation in which the whole of the region had a helix formation without converting to another structure. Optimized atomic geometries were obtained for both the models of normal and hypothetical structures. Energy comparison has indicated that optimized geometry led from the X-ray crystallographic structure has the lower potential energy than that of the hypothetical one in every case. This result strongly suggests that the conversion from a helix to another structure is mainly determined by ‘potential energy’ of the local region at the ending of the helix.

Vibrio vulnificus, an opportunistic marine bacterium that causes a serious, often fatal, infection in humans, requires iron for its pathogenesis. This bacterium exports vulnibactin for iron acquisition from the environment. The mechanisms of vulnibactin biosynthesis and ferric-vulnibactin uptake systems have recently been reported, while the vulnibactin export system has not been reported. Mutant growth under low-iron concentration conditions and a bioassay of the culture supernatant indicate that the VV1_0612 protein plays a crucial role in the vulnibactin secretion as a component of the resistance-nodulation-division (RND)-type efflux system in V. vulnificus M2799. To identify which RND protein(s) together with VV1_0612 TolC constituted the RND efflux system for vulnibactin secretion, deletion mutants of 11 RND protein-encoding genes were constructed. The growth inhibition of a multiple mutant (Δ11) of the RND protein-encoding genes was observed 6 h after the beginning of the culture. Furthermore, ΔVV1_1681 exhibited a growth curve that was similar to that of Δ11, while the multiple mutant except ΔVV1_1681 showed the same growth as the wild-type strain. These results indicate that the VV1_1681 protein is involved in the vulnibactin export system of V. vulnificus M2799. This is the first genetic evidence that vulnibactin is secreted through the RND-type efflux systems in V. vulnificus.

The 6-, 9-, 12-, 15-, 18-, 21-, 24-, and 27-membered unsaturated thiacrown ethers 1-8 were formed by reaction of cis-1,2-dichloroethylene with sodium sulfide in acetonitrile. Crystal structures of 4-8 were determined by X-ray crystallography, and it was found that all sulfur atoms of 5-8 direct to the inside of the ring (endodentate). All of the ORTEP drawings show that there are cavities in these molecules, and the cavity sizes in 4-8 were 1.76, 2.34, 3.48, 4.43, and 5.36 A, respectively. The UV spectra of 4-8 showed absorption maximums at the range of 255-276 nm in acetonitrile, and the absorption maximums of 4-8 were found to shift to longer wavelengths by changing the solvent from acetonitrile to cyclohexane. The cyclic voltammograms of 4-8 indicate that the larger unsaturated thiacrown ethers were oxidized more easily than the smaller systems, and unsaturated thiacrown ethers were oxidized more easily than corresponding saturated systems. The reaction of 4 with silver trifluoroacetate in acetone afforded the colorless complex Ag(I)(C2H2S)5(CF3COO) 9. The crystal structure of 9 was determined by X-ray analysis, and it was found that three of the five sulfur atoms bonded to the silver atom.

General saddlepoint approximations are derived for the distributions of statistics under an elliptical population. The technique is applied to obtain the tail probabilities of latent roots of a sample covariance matrix. It is shown that the method based on normalizing transformations by Tsuchiya and Konishi (1997) is efficient for the sample correlation coefficient in an elliptical sample. The transformation of reducing the asymptotic kurtosis of a statistic to zero is also proposed to prevent deficiencies in general saddlepoint approximations and utilized for the sample coefficient of variation and Student's t in elliptical samples. Some numerical comparisons are made to examine the efficiency and to check the accuracy of the resulting approximations.

Tyrosinase is a key enzyme in the synthesis of melanin and is widely distributed in animals, plants, and microorganisms. As excessive melanin production causes not only hyperpigmenting effects on human skin but also melanosis in various foods, an inhibitor of tyrosinase has become of interest lately from a practical point of view. In the present study, we purified the tyrosinase inhibitor produced by Trichoderma viride strain H1-7 from a marine environment. The purified inhibitor showed a single peak on HPLC. The chemical structure of this compound was determined by NMR and mass spectrometry analyses. The structure was the same as homothallin II that has been isolated as an antibiotic from T. koningii and T. harzianum. The inhibitor showed competitive inhibition against mushroom tyrosinase.

By employing C 60 as a chemical probe, the photolysis of benzylchlorodiazirine has been proposed to form carbene and the rearranged products via the excited state.

The use of general saddlepoint approximations is investigated for the problem of approximating the tail probabilities of statistics in multivariate analysis. A method based on normalizing transformations is proposed to prevent po¬tential deficiencies in general saddlepoint approximations. The efficiency of the proposed method is illustrated through examples of the sample correlation

By using density functional theory calculations, it is found that the [2+1] cycloaddition derivatives of armchair ( m , m ) single-wall carbon nanotube (SWNT) evolve from open structure to closed three-membered ring structure as m >11 for NH addition, m >10 for O and CH 2 additions, and m >5 for SiH 2 addition. The diameter upper limit of the opening of the sidewall of SWNTs upon [2+1] cycloaddition is predicted to be about 15 A.

In Japan, the elderly patients generally account for high percentages of both inpatients and outpatients. As aging of the population accelerates, it will become increasingly important to properly detect, assess and intervene for psychiatric symptoms of the elderly patients to establish differential diagnoses. Thus, we must assess all existing psychiatric symptoms by keeping in mind the brain/physical conditions and social circumstances of the elderly patients and considering not just their complaints but also objective information from other organizations/services. In doing so, particular emphasis should be placed on assessing consciousness. Decreased alertness should not be dismissed as "old age". Medical professionals and caregivers must carefully assess psychiatric symptoms in the elderly patients while respecting their self-esteem.

Vibrio vulnificus, an opportunistic marine bacterium that causes a serious, often fatal, infection in humans, requires iron for its pathogenesis. This bacterium uses iron from the environment via the vulnibactin-mediated-iron-uptake system. In this study, we constructed the deletion mutants of the genes encoding the proteins involved in the vulnibactin-mediated-iron-uptake system, isochorismate synthase (ICS), vulnibactin utilization protein (VuuB), periplasmic ferric-vulnibactin binding protein (FatB), and ferric-vulnibactin receptor protein (VuuA). The Δics and ΔvuuA mutants were unable to grow under low-iron concentration conditions compared with the isogenic wild-type, indicating that the involvement of ICS in the vulnibactin biosynthesis pathway and uptake of ferric-vulnibactin through the VuuA receptor protein are essential for V. vulnificus M2799 growth under low-iron concentration conditions. Similar growth impairment was also observed in ΔfatB, with growth recovery of this mutant observed 6 h after the beginning of the culture. These results indicate that there must be other periplasmic ferric-vulnibactin binding proteins in V. vulnificus M2799 that complement the defective fatB gene. Complementary growth studies confirmed that VatD protein, which functions as a periplasmic ferric-aerobactin binding protein, was found to participate in the ferric-vulnibactin uptake system in the absence of FatB. Furthermore, the expression of ics, vuuB, fatB, vuuA, and vatD genes was found to be regulated by iron and the ferric uptake regulator.

A probabilistic multidimensional scaling model is proposed. The model assumes that the coordinates of each stimulus are normally distributed with variance Σi = diag(σ21, … σ2Ri). The advantage of this model is that axes are determined uniquely. The distribution of the distance between two stimuli is obtained by polar coordinates transformation. The method of maximum likelihood estimation for means and variances using the EM algorithm is discussed. Further, simulated annealing is suggested as a means of obtaining initial values in order to avoid local maxima. A simulation study shows that the estimates are accurate, and a numerical example concerning the location of Japanese cities shows that natural axes can be obtained without introducing individual parameters.

The present paper proposes a method of construction of multiple uni-dimensional scales by classifying a set of qualitative variables into groups. The method consists of Hayashi's third method of quantification and fuzzy c-means clustering. Weight parameter, agi, which indicates a degree that each item belongs to each group, facilitates the classification. As numerical examples, four artificial data sets are analyzed and the characteristics of the method are examined. Two real data sets are also analyzed and it is observed that interpretable groups are obtained in both data sets.

Photochemical reactions of Lu(3)N@I(h)-C(80) with disiliranes 1 and 2 produce several isomeric adducts. Spectroscopic analyses characterize the most stable isomers as 1,4(AA) adducts, which consist of paired twist conformers at rt. The electrochemical and theoretical studies reveal that the HOMO-LUMO energy gaps of the 1,4(AA) adducts are smaller than that of Lu(3)N@I(h)-C(80) because the electron-donating groups effectively raise the HOMO levels.

In recent years, endohedral metallofullerenes have attracted tremendous interest not only in physics and chemistry, but also in interdisciplinary areas, such as materials and biological sciences. In this concept article we highlight recent results on different endohedral metallofullerenes based on lanthanides and their derivatives. The chemical and excited state reactivities of endohedral metallofullerenes are discussed for various endohedral clusters. Most important is the part that covers spectroscopic and kinetic assays of reductive and oxidative charge transfer evolving from photoexcited electron donors and electron acceptors, respectively, in a variety of electron donor-acceptor conjugates. Towards this end, we refer to the applications of endohedral metallofullerenes in photovoltaic devices that feature greater efficiency than devices fabricated with empty fullerenes. Herein, we focus mainly on results obtained in the groups of Akasaka, Echegoyen, and Guldi.

For the first time, a C(60) derivative (1) and two different lanthanum metallofullerene derivatives, La@C(82)Py(2) and La(2)@C(80)Py (3), that feature a pyridyl group as a coordination site for transition-metal ions have been synthesized and integrated as electron acceptors into coordinative electron-donor/electron-acceptor hybrids. Zinc tetraphenylporphyrin (ZnP) served as an excited-state electron donor in this respect. Our investigations, by means of steady-state and time-resolved photophysical techniques found that electron transfer governs the excited-state deactivation in all of these systems, namely 1/ZnP, 2/ZnP, and 3/ZnP, whereas, in the ground state, notable electronic interactions are lacking. Variation of the electron-accepting fullerene or metallofullerene moieties provides the incentive for fine-tuning the binding constants, the charge-separation kinetics, and the charge-recombination kinetics. To this end, the binding constants, which ranged from log K(assoc) =3.94-4.38, are dominated by axial coordination, with minor contributions from the orbital overlap of the curved and planar π systems. The charge-separation and charge-recombination kinetics, which are in the order of 10(10) and 10(8) s(-1) , relate to the reduction potential of the fullerene and metallofullerenes, respectively.

In recent years, endohedral metallofullerenes have attracted tremendous interest not only in physics and chemistry, but also in interdisciplinary areas, such as materials and biological sciences. In this concept article we highlight recent results on different endohedral metallofullerenes based on lanthanides and their derivatives. The chemical and excited state reactivities of endohedral metallofullerenes are discussed for various endohedral clusters. Most important is the part that covers spectroscopic and kinetic assays of reductive and oxidative charge transfer evolving from photoexcited electron donors and electron acceptors, respectively, in a variety of electron donor-acceptor conjugates. Towards this end, we refer to the applications of endohedral metallofullerenes in photovoltaic devices that feature greater efficiency than devices fabricated with empty fullerenes. Herein, we focus mainly on results obtained in the groups of Akasaka, Echegoyen, and Guldi.

Little is known about the chemical properties of carbide cluster metallofullerenes (CCMFs). Here we report the photochemical reaction of a newly assigned CCMF Sc(2)C(2)@C(2v)(5)-C(80) with 2-adamantane-2,3-[3H]-diazirine (AdN(2), 1), which provides a carbene reagent under irradiation. Five monoadduct isomers (2a-2e), with respective abundances of 20%, 40%, 25%, 5%, and 10%, were isolated and characterized with a combination of experimental techniques including unambiguous single-crystal X-ray crystallography. Results show that the two Sc atoms of the bent Sc(2)C(2) cluster tend to move in most cases, whereas the C(2)-unit is almost fixed. Accordingly, it is difficult to explain the addition patterns by considering the strain and charge density on the cage with a fixed cluster, and thus a moving cluster may account for the addition patterns. These results show that the situation of CCMFs is more complicated than those in other metallofullerenes. Furthermore, a thermal isomerization process from 2b to 2c was observed, confirming that the most abundant isomer 2b is a kinetically favored adduct. Finally, it is revealed that the electronic and electrochemical properties of pristine Sc(2)C(2)@C(2v)(5)-C(80) have been markedly altered by exohedral modification.

X-ray analyses of the cocrystals of a series of carbide cluster metallofullerenes Sc(2)C(2)@C(2n) (n = 40-42) with cobalt(II) octaethylporphyrin present new insights into the molecular structures and cluster-cage interactions of these less-explored species. Along with the unambiguous identification of the cage structures for the three isomers of Sc(2)C(2)@C(2v)(5)-C(80), Sc(2)C(2)@C(3v)(8)-C(82), and Sc(2)C(2)@D(2d)(23)-C(84), a clear correlation between the cluster strain and cage size is observed in this series: Sc-Sc distances and dihedral angles of the bent cluster increase along with cage expansion, indicating that the bending strain within the cluster makes it pursue a planar structure to the greatest degree possible. However, the C-C distances within Sc(2)C(2) remain unchanged when the cage expands, perhaps because of the unusual bent structure of the cluster, preventing contact between the cage and the C(2) unit. Moreover, analyses revealed that larger cages provide more space for the cluster to rotate. The preferential formation of cluster endohedral metallofullerenes for scandium might be associated with its small ionic radius and the strong coordination ability as well.

Acinetobacter baumannii is a major cause of both community-associated and nosocomial infections worldwide. These infections are difficult to treat because the bacterium rapidly develops resistance to multiple antibiotics. However, little is known about the nature of the innate cellular response to A. baumannii infection. In the present study, we identified the cells infiltrating the lungs of mice with Acinetobacter pneumonia and analyzed their response to infection. Normal mice eradicated the A. baumannii infection within 3 days of inoculation. Neutrophils were rapidly recruited to the lungs, followed by macrophages and NK1.1(+) cells. Neutrophil-depleted mice showed acute and severe symptoms, and all of the mice died within 3 days of inoculation. The majority of macrophage-depleted mice responded in a similar manner to the control mice. These results indicate that neutrophils are essential for the elimination of A. baumannii. Half of NK1.1(+) cell-depleted mice died within 1 day of inoculation and the number of infiltrating neutrophils was lower than that in control mice up until 3 days post-inoculation. Moreover, the expression levels of keratinocyte chemoattractant protein (KC) decreased in NK1.1(+) cell-depleted mice. These results indicate that NK1.1(+) cells recruit neutrophils during the early phase of Acinetobacter infection by increasing KC expression.

Since the first discovery of fullerenes in 1985, the insertion of one or more atoms into a hollow fullerene cage has been attempted. Furthermore, synthesis and extraction of metallofullerene, La@Cn, were reported in 1991. Recent successful isolation and purification of metallofullerenes have facilitated the investigation of their chemical properties. This mini-review presents a summary of the recent progress of chemical functionalization and supramolecular chemistry of M@C82. Selective functionalization and successful structural analysis of derivatives have revealed their chemical features arising from endohedral metal doping.

Novel C60 derivatives (III) are synthesized without causing a drastic change of the electronic properties of the fullerene cage.

The complexation behavior of La(2)@C(80) dimetallofullerenes with organic donor molecules (D) in solution has been investigated. It has been shown that La(2)@C(80) and D form 1:1 complexes as a result of electron transfer interactions in the ground state. The equilibrium between La(2)@C(80)/D and [La(2)@C(80)](•-)/[D](+) in solution is readily controlled by changing the temperature and solvent.

Two stable electron donor-acceptor conjugates, that is, 3 and 5b, employing La(2)@I(h)-C(80) and Sc(3)N@I(h)-C(80), on one hand, and zinc tetraphenylporphyrin, on the other hand, have been prepared via [1+2] cycloaddition reactions of a diazo precursor. Combined studies of crystallography and NMR suggest a common (6,6)-open addition pattern of 3 and 5b. Still, subtly different conformations, that is, a restricted and a comparatively more flexible topography, emerge for 3 and 5b, respectively. In line with this aforementioned difference are the electrochemical assays, which imply appreciably stronger I(h)-C(80)/ZnP interactions in 3 when compared to those in 5b. Density functional calculations reveal significant attractions between the two entities of these conjugates, as well as their separately localized HOMOs and LUMOs. The geometrical conformations and LUMO distributions of 3 and 5b, at our applied computational level, are slightly varied with their different endohedral clusters. The clusters also exert different impact on the excited state reactivity of the conjugates. For example, 3 undergoes, upon photoexcitation, a fast charge separation process and yields a radical ion pair, whose nature, namely, (La(2)@C(80))(•-)-(ZnP)(•+)) versus (La(2)@C(80))(•+)-(ZnP)(•-)), varies with solvent polarity. 5b, on the other hand, afforded the same (Sc(3)N@C(80))(•-)-(ZnP)(•+)) radical ion pair regardless of the solvent.

Bis-functionalization of endohedral metallofullerene La(2)@C(80) by carbene addition is reported herein. Adducts were characterized using spectroscopic and single-crystal X-ray structure analyses. Crystallographic data for bisadduct La(2)@C(80)(CClPh)Ad (3, Ad = adamantylidene) revealed that both carbene additions occur at the 6,6-bond junction on the C(80) cage with ring cleavages and that La atoms are positioned collinearly with spiro carbons. It is noteworthy that the La-La distance in 3 is highly elongated by carbene bis-functionalization compared to the distance in pristine La(2)@C(80) and reported functionalized derivatives. The metal positions were confirmed through density functional calculations.

Since the first discovery of fullerenes in 1985, the insertion of one or more atoms into a hollow fullerene cage has been attempted. Furthermore, synthesis and extraction of metallofullerene, La@C(n), were reported in 1991. Recent successful isolation and purification of metallofullerenes have facilitated the investigation of their chemical properties. This mini-review presents a summary of the recent progress of chemical functionalization and supramolecular chemistry of M@C(82). Selective functionalization and successful structural analysis of derivatives have revealed their chemical features arising from endohedral metal doping.

To construct a no-arbitrage defaultable bond market, we work on the state price density framework. Using the heat kernel approach (HKA for short) with the killing of a Markov process, we construct a single defaultable bond market that enables an explicit expression of a defaultable bond and credit spread under quadratic Gaussian settings. Some simulation results show that the model is not only tractable but realistic.

Thermal carbosilylation of endohedral dimetallofullerene La(2)@I(h)-C(80) with silirane (silacyclopropane) is reported herein for the first time. Two diastereomers of the carbosilylated La(2)@I(h)-C(80) have been isolated and characterized. The fascinating molecular structure of one diastereomer of the carbosilylated derivatives has been determined unambiguously using X-ray crystallographic analysis. Detailed characteristics of the molecular structures including their metal atom movements have also been revealed using NMR spectroscopic studies and computational calculations. Results revealed that two La atoms move dynamically inside the carbon sphere. Furthermore, electrochemical study has demonstrated that carbosilylation is effective to fine-tune the La(2)@I(h)-C(80) electronic properties.

The synthesis and characterization of various endohedral metallofullerenes and their derivatives are described. The encapsulated metal atoms' positions and movements were determined using NMR study, X-ray crystallographic analysis, and theoretical calcula- tions. The results of electrochemical investigations clarified the relation between the elec- tronic properties and the π-electron systems of the fullerene endohedrals.

This paper describes the convenient method of isolating endohedral metallo- fullerenes by means of selective reduction from carbon soot extracts. Successful isolation in large amount by utilizing this method allows examination of the selective chemical modifi- cation of monometallofullerenes. Furthermore, isolation of missing metallofullerenes as their derivatives is also mentioned.

A series of13C-enriched monoytterbium endohedral metallofullerenes (EMFs)—Yb@C2n (n = 40, 41, 42)—was synthesized and isolated. Their cage structures were systematically determined for the first time using computational and experimental 13C NMR studies. The results revealed that all isomers adopt cage structures conforming to the isolated pentagon rule. In detail, Yb@C80 possesses the C2v(3) cage; Yb@C82(I, II, III) bear Cs(6), C2(5), and C2v(9) cages, respectively; and Yb@C84(II, III, IV) have C2(13), C1(12), and C2(11) cage structures, respectively. This is the first report describing C2(13)-C84 and C1(12)-C84 cage structures. It is noteworthy that the cage structures found for mono-EMFs generally differ from either the corresponding empty fullerenes or the related EMFs encapsulating more than one metal atom, indicating that the metal atom inside the fullerene cage plays an important role in determining the EMF structure. On the basis of the fact that the structure of Yb@C2(13)-C84 resembles that of Yb@...

We report for the first time the versatile Ce(2)@I(h)-C(80) building block toward synthesizing a novel electron donor-acceptor conjugate, Ce(2)@I(h)-C(80)-ZnP (1). A systematic investigation of the charge transfer chemistry documents a reductive charge transfer (i.e., formation of (Ce(2)@I(h)-C(80))(*-)-(ZnP)(*+)) in nonpolar media (i.e., toluene/THF), while an oxidative charge transfer (i.e., formation of (Ce(2)@I(h)-C(80))(*+)-(ZnP)(*-)) dominates in polar media (i.e., benzonitrile/DMF). Reduction of the [Ce(2)](6+) cluster, which is highly localized and collinearly arranged with respect to the quaternary bridge carbon, is sufficiently exothermic in all solvents. Notably weak is the electronic coupling between the [Ce(2)](6+) cluster and the electron-donating ZnP. The oxidation of C(80)(6-) and the simultaneous reduction of ZnP, on the other hand, necessitate solvent stabilization. In such a case, the strongly exothermic (Ce(2)@I(h)-C(80))(*-)-(ZnP)(*+) radical ion pair state formation is compensated within the framework of a nonadiabatic charge transfer by a C(80)(6-)/ZnP electronic matrix element, as the sum of good overlap and short distance, that exceeds that for [Ce(2)](6+)/ZnP.

A series of(13)C-enriched monoytterbium endohedral metallofullerenes (EMFs)-Yb@C(2n) (n = 40, 41, 42)-was synthesized and isolated. Their cage structures were systematically determined for the first time using computational and experimental (13)C NMR studies. The results revealed that all isomers adopt cage structures conforming to the isolated pentagon rule. In detail, Yb@C(80) possesses the C(2v)(3) cage; Yb@C(82)(I, II, III) bear C(s)(6), C(2)(5), and C(2v)(9) cages, respectively; and Yb@C(84)(II, III, IV) have C(2)(13), C(1)(12), and C(2)(11) cage structures, respectively. This is the first report describing C(2)(13)-C(84) and C(1)(12)-C(84) cage structures. It is noteworthy that the cage structures found for mono-EMFs generally differ from either the corresponding empty fullerenes or the related EMFs encapsulating more than one metal atom, indicating that the metal atom inside the fullerene cage plays an important role in determining the EMF structure. On the basis of the fact that the structure of Yb@C(2)(13)-C(84) resembles that of Yb@C(2)(5)-C(82), a metal-templated growth process was proposed as a kinetic factor controlling EMF formation. Furthermore, previous electrochemical studies of divalent EMFs have failed to observe their oxidation potentials, which have raised the assumption that such species are large-bandgap molecules. This study revealed that all isomers of Yb@C(2n) (n = 40, 41, 42) display one or two reversible oxidation steps together with four reversible reduction processes in 1,2-dichlorobenzene, even at a low scan rate (20 mV/s), which enables estimation of their electrochemical bandgaps (DeltaE = (ox)E(1)-(red)E(1)). The results show a DeltaE value of 0.88-1.41 V for Yb@C(2n) (2n = 40, 41, 42), which is much larger than the values of trivalent mono-EMFs (DeltaE0.5 V), but generally smaller than those of metal nitride cluster EMFs (1.4 VDeltaE2.1 V). Results further demonstrated that the DeltaE values correlate reasonably with their relative abundances.

We herein report the investigation of N@C(60) exposed to laser flash excitation to exhibit the acceleration of the decay of (N@C(60))* by the encased N atom.

The first regioselective functionalization of La@C 82 by two different groups has been performed. Bis-adducts of La@C 82 with Cp * and adamantylidene were synthesized by using two different routes and characterized. Spectroscopic analysis and theoretical calculations reveal that the addition position is controlled by the charge density and p-orbital axis vector value of the fullerene cage.

Stable donor-acceptor conjugates (2, 3) involving an endohedral metallofullerene, La(2)@I(h)-C(80), and pi-extended tetrathiafulvalene (exTTF) have been synthesized by highly regioselective 1,3-dipolar cycloadditions of exTTF-containing azomethine ylides to the endofullerene, yielding exclusively [5,6] metallofulleropyrrolidines with C(1) symmetry in high yields (68-77%). The cyclic voltammograms (CVs) of the conjugates reveal the redox active character of the system due to the presence of both donor and acceptor groups, that is, exTTF and La(2)@I(h)-C(80), respectively. Furthermore, the electrochemically reversible character of the endofullerene confirms the presence of the [5,6] adduct. Despite the relatively close proximity between the exTTF and the endohedral metallofullerene (EMF), only a weak electronic interaction was observed in the ground state, as evidenced by absorption spectroscopy and CV measurements of 2 and 3. On the other hand, in the excited state the fast formation of a radical ion-pair state (i.e., 6.0 x 10(10) s(-1)), that is, the reduction of the electron accepting La(2)@C(80) and the oxidation of exTTF, evolves with lifetimes as long as several ns (3.0 x 10(8) s(-1)) in toluene. Transient absorption spectroscopy experiments confirmed these observations.

We construct default-free interest rate models in the spirit of the well-known Markov functional models: our focus is analytic tractability of the models and generality of the approach. We work in the setting of state price densities and construct models by means of the so called propagation property. The propagation property can be found implicitly in all of the popular state price density approaches, in particular heat kernels share the propagation property (wherefrom we deduced the name of the approach). As a related matter, an interesting property of heat kernels is presented, too.

This account describes the redox behaviors of endohedral metallofullerenes having remarkable electron-accepting and -donating abilities, which accompany the transformation between their paramagneti...

The recent widespread deployment of 3G technology has opened the possibility for high value digital content to be delivered to wireless-driven output terminals that may or may not be mobile. This calls for a robust DRM (Digital Rights Management) system that can protect copyrighted content from being illegally accessed. The conventional method of authenticating a registered user or a prospective content purchaser is by means of the username and password combination. However, this method raises many vulnerabilities, especially now that password attacks and phishing techniques are rampant. Enhanced user authentication schemes are thus needed to ensure that the content is delivered to the legitimate purchaser, and to combat piracy in the Internet in general. Our assumed DRM system utilizes 3G mobile devices, such as HSDPA (High Speed Downlink Packet Access) enabled mobile devices, to access the content. An essential part of the system is an access area restriction scheme; it is based on the physical location of the user's mobile device as estimated from the packet transmission time between the mobile device and the server. Together with personal information, the access location must be pre-registered to realize location-specific enforcement policies. This system is extremely flexible and supports a wide range of security policies; for example, the content provider can stipulate that service is terminated if the registered user moves away from the registered terminal through which he is accessing the content.

YfkE, a protein from Bacillus subtilis, exhibits homology to the Ca(2+):Cation Antiporter (CaCA) Family. In a fluorescence-based assay of everted membrane vesicles prepared from Na(+)(Ca(2+))/H(+) antiporter-defective mutant Escherichia coli KNabc, YfkE exhibited robust Ca(2+)/H(+) antiport activity, with a K (m) for Ca(2+) estimated at 12.5 muM at pH 8.5 and 113 muM at pH 7.5. Neither Na(+) nor K(+) served as a substrate. Mg(2+) also did not serve as a substrate, but inhibited the Ca(2+)/H(+) antiporter activity. The Ca(2+) transport capability of YfkE was also observed directly by transport assays in everted membrane vesicles using radiolabeled (45)Ca(2+). Transcriptional analysis from the putative yfkED operon using beta-garactosidase activity as a reporter revealed that both of the yfkE and yfkD genes are regulated by forespore-specific sigma factor, SigG, and the general stress response regulator, SigB. These results suggest that YfkE may be needed for Ca(2+) signaling in the sporulation or germination process in B. subtilis. ChaA is proposed as the designation for YfkE of B. subtilis.

The thermal reaction of La@C(82)(C(2v)) with 3-triphenylmethyl-5-oxazolidinone (1) in toluene affords benzyl monoadducts La@C(82)(C(2v))(CH(2)C(6)H(5)) (2a-2d). The same monoadducts are also obtained by the photoirradiation of La@C(82)(C(2v)) in toluene without the existence of 1. These reactions are applicable to paramagnetic metallofullerenes, such as La@C(82)(C(s)) and Ce@C(82)(C(2v)). The photoirradiation of La@C(82)(C(2v)) in 1,2-dichlorobenzene in the presence of alpha,alpha,2,4-tetrachlorotoluene also affords the monoadducts La@C(82)(C(2v))(CHClC(6)H(3)Cl(2)) (3a-3d). The monoadducts are fully characterized by spectroscopic analyses. Single-crystal X-ray structure analysis for 3d reveals the unique structure. Theoretical calculations show that the cage carbons having high spin densities are selectively attacked by radical species to form the monoadducts linked by a carbon-carbon single bond. The thermal reaction of La@C(82)(C(2v)) with 1 in benzene affords metallofulleropyrrolidine La@C(82)(C(2v))(C(2)H(4)NCPh(3)) (5), unlike the reaction in toluene.