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Syntheses of core-modified 24π pentaphyrin 7 and 20π homoporphyrin 8 are reported. The freebase form of 7 exhibits optical and 1 H NMR spectroscopic behavior corresponding to a 4nπ nonaromatic topology at 298 K. However, upon lowering the temperature to 188 K, 7 exhibits weak aromaticity because of a small conformational change. Protonation of the imine pyrrolic nitrogen atoms results in sharpening of the absorption band with more than 100 nm red shift and two-fold increase in ϵ values. The 1 H NMR spectra show large shielding and deshielding of specific protons accompanied by twisting of pyrrole and thiophene rings from the mean plane of the macrocycle. These observations suggest a major structural change upon protonation. The single-crystal X-ray structure of protonated 7 a reveals a severe twisting of the macrocycle, especially at the ethene bridge, and the two thiophene rings adjacent to the ethene bridge are pointed above and below the plane of the ethene bridge (49.07° and 49.08°). The nucleus-independent chemical shift (NICS) values calculated at the center of the macrocycle for the freebase and protonated derivatives of 7 a and 7 b are -5.6, -8.3 ppm and -5.3, -8.4 ppm, respectively. The anisotropy-induced current density (AICD) plots suggest a clockwise circulation of π electrons. Taken together, the changes occurring in the optical spectra, 1 H NMR spectra, single-crystal X-ray structure and NICS calculation reflect a Mobius aromatic topology for protonated 7. However, the homoporphyrin 8 remains nonaromatic both in the freebase and protonated form.

Crocin is a pharmacologically active carotenoid pigment mainly present in the stigmas of Crocus sativus L. (Iridaceae). It has been well explored in experimental animal models of cognitive impairments, depression, anxiety and epilepsy. This study was designed to understand the effect of crocin on pentylenetetrazol (PTZ)-induced kindling development and its associated cognitive deficit in mouse. Crocin treatment at 5, 10 and 20 mg/kg p.o. doses showed a marked reduction in severity of PTZ-induced seizures. There was an increase in novel object preference index and discrimination ratio in the crocin-treated groups in the novel object recognition test. Its treatment also increased percentage spontaneous alternations in T-maze test at all the tested doses. Histopathological examination by Nissl staining showed a reduction in dark neurons in the hippocampal pyramidal layer of crocin-treated animals in contrast to vehicle control, indicating a decrease in neuronal damage. Biochemical estimations showed a significant increase in superoxide dismutase activity and reduced reactive oxygen species (ROS) in the hippocampus of crocin-treated animals. Immunohistochemistry results revealed attenuation in the levels of nuclear factor-κB (NF-κB) and phosphorylated NF-κB in the hippocampal sections of crocin-treated animals. The results of this study concluded that crocin treatment increased seizure threshold, thus inhibiting PTZ-induced kindling development and improving cognitive functions. The effect was found to be due to suppression of seizure-induced ROS generation and its linked NF-κB pathway-associated neuronal damage.

Molecular capsules form due to various interactions between molecules. Cyclotricatechylene (CTC) is a poly-phenolic macrocycle that has been shown to form capsule under highly basic conditions. Here, we describe the formation of a molecular capsule under ambient conditions, from CTC by addition of a guest molecule. The capsule is most probably forming through pure electrostatic interaction between the guest and CTC. The capsule formation has been studied using solution techniques such as NMR and Mass spectroscopy. The information about capsule formation is also obtained from the solid state structure using single crystal X-ray diffraction studies, which corroborates well with the findings in solution state. Upon changing the cation to a larger one, both capsule formation and the encapsulation are hindered. However, change of anions keeping the cation unchanged does not affect the assembly process.

A new fused core-modified 32π heptaphyrin with Möbius aromatic character is reported. The (1)H NMR data indicated a weak Möbius aromaticity at 298 K; however, at 213-183 K, the molecule predominates [4n]π Möbius conformation with strong diatropic ring current, which was further confirmed by X-ray analysis. The protonation experiment led to preservation of the Möbius aromaticity at 298 K. Nevertheless, the experimental results were further supported by theoretical studies. Overall, this study represents the first example of Möbius aromatic fused core-modified expanded porphyrin.

Combining oblique angle deposition with standard graphene transfer protocols, two planar arrays of metal nanoparticles are fabricated that are vertically separated by atomic dimensions, corresponding precisely to the thickness of a single layer of graphene, i.e., 0.34 nm. Upon illumination of light at an appropriate wavelength, the local electromagnetic field at the junction of the dimers can be increased dramatically, thereby resulting in the most sensitive graphene-plasmonic hybrid photodetector reported to date.

The medical costs for a type 2 diabetes patient are two to four times greater than the costs for a patient without diabetes. Bariatric surgery is the most effective weight-loss therapy and has marked therapeutic effects on diabetes. We estimate the economic effect of the clinical benefits of bariatric surgery for diabetes patients with BMI ≥ 35 kg/m². Using an administrative claims database of privately insured patients covering 8.5 million lives 1999-2007, we identify obese patients with diabetes, aged 18-65 years, who were treated with bariatric surgery identified using Healthcare Common Procedure Coding System codes. These patients were matched with nonsurgery control patients on demographic factors, comorbidities, and health-care costs. The overall return on investment (RoI) associated with bariatric surgery was calculated using multivariate analysis. Surgery and control patients were compared postindex with respect to diagnostic claims for diabetes, diabetes medication claims, and adjusted diabetes medication and supply costs. Surgery costs were fully recovered after 26 months for laparoscopic surgery. At month 6, 28% of surgery patients had a diabetes diagnosis, compared to 74% of control patients (P < 0.001). Among preindex insulin users, insulin use dropped to 43% by month 3 for surgery patients, vs. 84% for controls (P < 0.001). By month 1, medication and supply costs were significantly lower for surgery patients (P < 0.001). The therapeutic benefits of bariatric surgery on diabetes translate into considerable economic benefits. These data suggest that surgical therapy is clinically more effective and ultimately less expensive than standard therapy for diabetes patients with BMI ≥ 35 kg/m².

In this contribution, a stability analysis for a dynamic voltage restorer (DVR) connected to a weak ac system containing a dynamic load is presented using continuation techniques and bifurcation theory. The system dynamics are explored through the continuation of periodic solutions of the associated dynamic equations. The switching process in the DVR converter is taken into account to trace the stability regions through a suitable mathematical representation of the DVR converter. The stability regions in the Thevenin equivalent plane are computed. In addition, the stability regions in the control gains space, as well as the contour lines for different Floquet multipliers, are computed. Besides, the DVR converter model employed in this contribution avoids the necessity of developing very complicated iterative map approaches as in the conventional bifurcation analysis of converters. The continuation method and the DVR model can take into account dynamics and nonlinear loads and any network topology since the analysis is carried out directly from the state space equations. The bifurcation approach is shown to be both computationally efficient and robust, since it eliminates the need for numerically critical and long-lasting transient simulations. Copyright © 2011 John Wiley & Sons, Ltd. (This article was published online on [14 January 2011]. An error was subsequently identified. This notice is included in the online and print versions to indicate that both have been corrected [11 October 2011].)

Background: Solitary rectal ulcer syndrome (SRUS) is an uncommon disorder of evacuation. Management of bleeding ulcers is usually unsatisfactory with conventional treatment. Argon plasma coagulation (APC) has been reported to control bleeding; however, it has not been shown to result in ulcer healing. The aim of the present study was to: (i) to investigate the efficacy and safety of APC in controlling bleeding from SRUS; and (ii) to study its efficacy in the healing of ulcer/s. Methods: Twenty-four patients with bleeding SRUS diagnosed on clinical, colonoscopic, and histological findings were randomized to receive either standard care alone (12 patients) or to undergo multiple sessions of APC in addition (12 patients). All patients were followed up to determine ulcer healing. Results: Twenty-four patients with a mean duration of symptoms of 12.6 ± 4.8 months were included. Bleeding was controlled with one (n = 5) or two sessions (n = 7) of APC. Reduction in size and depth of ulcer was noted. Eight out of 12 patients who received APC had complete healing of ulcers after four to eight sessions, carried out 2–4 weeks apart. The remaining four patients had a reduction in size and depth of ulcers compared to their pretreatment appearance. All patients were advised to have a high intake of fluids, fiber and laxatives, and to undergo biofeedback and behavior modification therapy in addition to the treatment. Conclusions: APC controls bleeding in patients with SRUS and it also improves the healing of these ulcers.

Multi-dimensional Fourier Transform (FT) NMR spectroscopy is broadly used in chemistry[1] and spectral resolution is pivotal for its performance. Phase-sensitive, pure absorption mode signal detection[1a,2] is required for achieving high spectral resolution since an absorptive signal at frequency Ω0 rapidly decays proportional to 1/(Ω0-Ω)2 while a dispersive signal slowly decays proportional to 1/(Ω0-Ω). Hence, a variety of approaches were developed to accomplish pure absorption mode signal detection.[1a,2] Moreover, by use of techniques such as spin-lock purge pulses[3], phase cycling,[1a] pulsed magnetic field gradients,[4] or z-filters,[5] radio-frequency (r.f.) pulse sequences for phase-sensitive detection are designed to avoid ‘mixed’ phases, so that only phase errors remain which can then be removed by a zero- or first-order phase correction.

Research efforts were given towards development of low carbon high strength steels since recent past. The present study deals with the development of a low carbon high strength steel alloyed with Mn, Ni, Mo, Cu and microalloyed with Ti and Nb. The steel was subjected to three stage controlled rolling operation followed by accelerated cooling. The structure and properties of the steel at various processing conditions were evaluated. Microstructural observation reveals predominantly lath martensite along with twinned martensite structure at all processing conditions. High strength values at higher finish rolling temperatures have been obtained due to fine martensitic structure along with tiny precipitates of microalloying carbide and carbonitride. The strength value increases marginally at lower finishing temperature due to comparatively finer lath size of martensite and increased precipitation density of carbides, carbonitrides along with Cu particles. The variation in impact toughness properties at different finish rolling temperatures is found to be negligible at ambient and subambient temperatures. The formation of stable and large TiN/TiCN particles during casting have impaired the impact toughness values at ambient and at -40 degrees C temperatures.

We investigate experimentally the fluctuations of the conductance of a high mobility quantum wire. We show that scattering of electrons is not evenly distributed across the wire. In the centre of the wire electrons propagate almost ballistically. However, when the electrons are forced into the boundaries of the wire diffusive scattering occurs. This is seen as a dramatic enhancement of the variance and characteristic period of the fluctuations at the field at which maximum boundary scattering is predicted. We compare our results with recent theories and construct an empirical model to describe the transport processes in the wire.

We have investigated the temperature dependence of longitudinal resistivity of high mobility two dimensional (2D) electron systems in the strongly correlated regime (r s ∼ 4-5). The area of the samples was relatively small, typically 2 x 2 μm 2 . The resistivity followed an Efros-Shklovskii (ES)-type variable range hopping (VRH) behavior, Q(T) = Q 0 exp (T 0 /T) p , with p = 0.5. We found that in this regime, the pre-factor Q 0 increases by discrete steps of h/2e 2 as the carrier concentration (n) is increased, starting from Q 0 = h/e 2 at the lowest values of n close to the localization. The jumps in Q 0 were associated with an oscillation in the activation energy defined by To. We have discussed the observation of such quantized, temperature-independent resistivity pre-factors in the framework of electron assisted VRH.

A simple protocol for the three-component reaction of 4-hydroxycoumarin, pyrazole (II) and aldehydes to give the title compounds via a tandem Knoevenagel-Michael reaction followed by cyclization.

The pyrrole derivatives include a β-amino acid part and are thus of importance for pharmaceutical investigations.