Peculiar relics from Primordial Black Holes in the inflationary paradigm

Depending on various assumptions on the energy scale of inflation and assuming a primordial power spectrum of a step‐like structure, we explore new possibilities for Primordial Black Holes (PBH) and Planck relics to contribute substantially to Cold Dark Matter in the Universe. A recently proposed possibility to produce Planck relics in four‐dimensional string gravity is considered in this framework. Possible experimental detection of PBHs through gravitational waves is also explored. We stress that inflation with a low energy scale, and also possibly when Planck relics are produced, leads unavoidably to relics originating from PBHs that are not effectively classical during their formation, rendering the usual formalism inadequate for them.     

FeCp]+-induced hexafunctionalization of hexamethylbenzene with dendrons for the direct synthesis of redox-active iron-centered metallodendrimers

Phenol tri- and nonaallyl dendrons (3 and 7, respectively) were functionalized at the focal position to give the new triallyl dendrons 4 and 6 and the nonaallyl dendrons 11 and 13 that contain a iodoalkyl or a bromobenzyl termini. All these dendrons were used for the [FeCp]+-induced hexafunctionalization of hexamethylbenzene in [FeCp(eta6-C6Me6)][PF6] (1) under mild conditions in the presence of KOH. These reactions directly yielded the 18-allyl and 54-allyl dendrimers 9, 10, and 14 with a [FeCp(eta6-arene)]+ unit located at the dendrimer core. Cyclic voltammetry studies were recorded in THF and DMF with these metallodendrimers and compared with those of analogous dendrimers or complexes of smaller size that contain a [FeCp(eta6-arene)]+ unit at the core. The decreased rate of heterogeneous electron transfer when the dendritic size increases first disclosed by Diederich and Gross is confirmed. The variation of the redox potential of the Fe(II/I) redox system with increasing dendritic size is negligible even in a solvent of high dielectric constant such as DMF. This trend is attributed to fact that the involved "redox" orbital is buried on the metal center, well protected by the shell of alkyl chains (electron-reservoir nature), unlike in ferrocene. The chemical irreversibility increases in THF as the dendrimer size increases, due to more facile ligand substitution with THF at the 19-electron level when the chain bulk increases.     

PHOTODYNAMIC DAMAGE TO EGG LECITHIN LIPOSOMES*

Abstract— Egg lecithin liposomes were lysed by singlet oxygen (¹O*₂) generated by red light irradiation of oxygenated methylene blue (MB⁺) and by superoxide (O^?₂) generated by blue-green irradiation of oxygenated riboflavin (RF) in the presence of ethylenediaminetetraacetic acid (EDTA) or reduced nicotinamide adenine dinucleotide (NADH). The MB⁺/O₂ sensitized process is more efficient in alkaline solutions, attributed to the stabilization of the triplet state di-cation. The small increase of the lysis efficiency from pH4 to pH9 for the RF/EDTA/O₂ system suggests that HO^?₂ may be more damaging than O^?₂. Estimates based on large-target reaction kinetics indicate that ¹O*₂ is about 200 times more effective than superoxide for inducing liposome lysis. Similar experiments with saturated 1 -α-phosphatidylcholine dipalmitoyl liposomes showed no photosensitized lysis for either system.     

TRIPLET EXCITED STATES OF 4'',5''-PHOTOMONOADDUCTS OF 3- CARBETHOXYPSORALEN and 8-METHOXYPSORALEN WITH DNA NUCLEOSIDES

Abstract— Triplet absorption spectra, triplet extinction coefficient and intersystem crossing for 4',5'-monocycloadducts of 3-carbethoxypsoralen (3-CPs) with thymidine (dThd) and uridine (dUrd) in ethanol have been investigated in order to elucidate whether their triplet state properties could be the limitating step for a further photoreaction of 3-CPs monoadducts with DNA nucleosides. The comparison between the triplet characteristics of 4',5'-monoadducts of 3-CPs and those of 8-methoxypsoralen (8-MOP) shows that the quantum yield is much higher in the case of 3-CPs than for 8-MOP. The monofunctionality of 3-CPs cannot therefore be ascribed to the triplet excited states properties of its monoadducts. It is likely that steric hindrance introduced by the bulky carbethoxy group remains a reasonable explanation.     

Fungicidal properties of meso-arylglycosylporphyrins: influence of sugar substituents on photoinduced damage in the yeast Saccharomyces cerevisiae

A series of neutral meso-arylglycosylporphyrins has been tested in order to evaluate their potency as antifungal agents against the yeast Saccharomyces cerevisiae. Photodynamic activity of these molecules results in intracellular damage as evidenced by the loss of clonogenicity and DNA fragmentation. The ability of these photosensitizers to permeate yeast cells is determined by microspectrofluorimetry and is correlated with their antifungal potency. Amphiphilic porphyrin derivatives are shown to exhibit the more pronounced photoactivity.     

Molecular batteries: ferrocenylsilylation of dendrons, dendritic cores, and dendrimers: new convergent and divergent routes to ferrocenyl dendrimers with stable redox activity

The ferrocenylsilylation of the phenol triallyl dendron 2, of the phenol nonaallyl dendron 4, and of the 9-, 27-, 81-, and 243-allyl dendrimers 7-10 (monitored by the disappearance of the signals of the olefinic protons in 1H NMR spectra) has been achieved using ferrocenyldimethylsilane 1 and Karstedt's catalyst in diethyl ether at 40 degrees C, yielding the corresponding ferrocenyl dendrons and dendrimers. An alternative convergent synthesis of the nonaferrocenyl dendron 5 was carried out by reaction of the triferrocenyl dendron 2 with a protected triododendron followed by deprotection. Reaction of the nonaferrocenyl dendron 5 with hexakis(bromomethyl)benzene gave the 54-ferrocenyl dendron 6. All the ferrocenyl dendron and dendrimers produce a chemically and electrochemically reversible ferrocenyl oxidation wave at seemingly the same potential. Stable platinum electrodes modified with the high ferrocenyl dendrimers were fabricated. The soluble orange-red ferrocenyl dendrimers can also be oxidized in CH2Cl2 by [NO][PF6] to the insoluble deep blue polyferrocenium dendrimers. For instance, the 243-ferrocenium dendrimer has been characterized by its Mossbauer spectrum, which is of the same type as that of ferrocenium itself. The ferrocenium dendrimers can be reduced without any decomposition back to the ferrocenyl dendrimer, indicating that these multielectronic redoxstable dendrimers behave as molecular batteries.     

Sideband transitions and two-tone spectroscopy of a superconducting qubit strongly coupled to an on-chip cavity

Sideband transitions are spectroscopically probed in a system consisting of a Cooper pair box strongly but nonresonantly coupled to a superconducting transmission line resonator. When the Cooper pair box is operated at the optimal charge bias point, the symmetry of the Hamiltonian requires a two-photon process to access sidebands. The observed large dispersive ac-Stark shifts in the sideband transitions induced by the strong nonresonant drives agree well with our theoretical predictions. Sideband transitions are important in realizing qubit-photon and qubit-qubit entanglement in the circuit quantum electrodynamics architecture for quantum information processing.     

Tunable coupling of superconducting qubits

We study an LC circuit implemented using a current-biased Josephson junction (CBJJ) as a tunable coupler for superconducting qubits. By modulating the bias current, the junction can be tuned in and out of resonance and entangled with the qubits coupled to it. One can thus implement two-qubit operations by mediating entanglement. We consider the examples of CBJJ and charge-phase qubits. A simple recoupling scheme leads to a generalization to arbitrary qubit designs.     

Compact three-dimensional camera for robot and vehicle guidance

A very compact 3-D range sensor for robot and vehicle guidance is described. A dual aperture mask in a camera lens is used to transform a small commercially available CCD video camera into a ranging sensor. An active system using a projected laser beam provides a 360° range map which can be used to plan trajectories, either for robots or autonomous vehicles. Good quality panoramic intensity and 3-D images were obtained. Accuracy, speed of acquisition, and cost are discussed. Experimental results are presented.