Green-to-Red Electrochromic Fe(II) Metallo-Supramolecular Polyelectrolytes Self-Assembled from Fluorescent 2,6-Bis(2-pyridyl)pyrimidine Bithiophene.

The structure and properties of metallo-supramolecular polyelectrolytes (MEPEs) self-assembled from rigid 2,6-bis(2-pyridyl)pyrimidine and the metal ions FeII and CoII are presented. While FeL1-MEPE (L1 = 1,4-bis[2,6-bis(2-pyridyl)pyrimidin-4-yl]benzene) is deep blue, FeL2- and CoL2-MEPE (L2 = 5,5'-bis[2,6-bis(2-pyridyl)pyrimidin-4-yl]-2,2'-bithiophene) are intense green and red in color, respectively. These novel MEPEs display a high extinction coefficient and solvatochromism. Ligand L2 shows a high absolute fluorescence quantum yield (Φf = 82%). Viscosity and static light-scattering measurements reveal that the molar masses of these MEPEs are in the range of 1 × 108 g/mol under the current experimental conditions. In water, FeL1-MEPE forms a viscous gel at 20 °C (c = 8 mM). Thin films of high optical quality are fabricated by dip coating on transparent conducting indium tin oxide (ITO) glass substrate. Optical, electrochemical, and electrochromic properties of the obtained MEPEs are presented. Green to red and blue to colorless electrochromism is observed for FeL2-MEPE and FeL1-MEPE, respectively. The results show that the electrochromic properties are affected by the ligand topology. The Fe-MEPEs show a reversible redox behavior of the FeII/FeIII couple at 0.86 and 0.82 V versus Fc+/Fc and display an excellent redox cycle stability under switching conditions. FeL2-MEPE in its oxidized state exhibits a broad absorption band covering the near-IR region (ca. 1500 nm) due to the ligand-to-metal charge transfer transition originating due to charge delocalization in the bithiophene spacer.

Spring-Loaded Transpatatal Arch with Turbo-V Springs for Correction of Severe Torsiversion.

OBJECTIVES: The aim of this case report is to introduce an appliance that can be used for correcting severe bilateral symmetric rotation (more than 900) ofsecondpremolars in adult patient. Appliance design and testing: This is a case report ofa 27-year-old female patient with permanent dentition having Class I malocclusion with bi-alveolar dentoalveolar protrusion defined by a severe bilateral rotation (more than 90-) of upper second premolars. Since it was a case of maximum anchorage, we decided to extract upper and lower arch first premolars, and the upper and lower arch were strapped with fixed orthodontic appliance with MBT 0.022 slot PEA brackets and then a spring-loaded transpalatal arch with turbo-Vsprings appliance used to correct severely rotated premolars. After 4 months, both the premolars were orthodontically brought into proper alignment. Circumferential supracrestalfibrotomy was planned to prevent relapse. CONCLUSION: Spring-loaded transpalatal arch with turbo- Vsprings appliance can be very effective for correcting severe bilateral rotation (more than 900) of premolar teeth.

Effortless stabilization of lingual retainer wire using customized clip.

The accurate positioning of the fixed lingual bonded retainer wire is one of the challenging processes in bonding fixed retainer. Though several methods have been introduced to stabilize the lingual bonded retainer, each technique has an inherent draw back. To overcome this we have designed a customized clip which is similar to Kesling Seperator to aid in accurate and precise positioning of lingual retainer wire.

Tooth separation potential problems.

A displaced orthodontic elastic separator was proposed as being the source of a gingival abscess that progresses to severe bone loss and exfoliation in a healthy adolescent patient with sound periodontal status prior to commencement of orthodontic treatment. After one year of undergoing orthodontic treatment, the patient presented with dull pain and mobility in the left upper permanent molar for which there was no apparent etiology. On clinical examination the patient had gingival inflammation, associated with a deep pocket and severe mobility (Grade III) in relation to the same teeth. Radiographic examination ofan Orthopantomogram (OPG) and IntraOral Periapical Radiograph (IOPAR) revealed a chronic periodontal abscess with severe necrosis of the periodontal ligament and severe alveolar bone loss. On curettage it was found that there was orthodontic elastic separator which was displaced sub gingivally. Active orthodontic forces were temporarily removed and splinting was done. 6 month follow up showed no mobility and significant improvement of alveolar bone height.

New modular manganese(I) tricarbonyl complexes as PhotoCORMs: in vitro detection of photoinduced carbon monoxide release using COP-1 as a fluorogenic switch-on probe.

Five manganese(i) tricarbonyl complexes of the general formulae [Mn(bpea(N=CHC6H4R))(CO)3]PF6 and [Mn(bpea(NHCH2C6H4R))(CO)3]PF6 based on the tridentate bis(pyrazolyl)ethylamine (bpea) ligand, each containing a pendant 4-substituted phenyl group with R = H, I, and C≡C-H, were synthesized and fully characterized, including X-ray structure analysis for three compounds. All complexes are stable in the dark in aqueous buffer for an extended period of time. However, CO-release could be triggered by illumination at 365 nm, establishing these compounds as novel photoactivatable CO-releasing molecules (PhotoCORMs). The influence of the imine vs. amine group in the ligands on the electronic structure and the photophysical behavior was investigated with the aid of DFT and TDDFT calculations. Solution IR studies on selected compounds allowed identification of intermediates resulting from the photoreaction. Finally, light-induced CO release from a model compound was demonstrated both in PBS buffer and in vitro in human umbilical vein endothelial cells (HUVECs) using COP-1 as a fluorescent switch-on probe.

Penta - V Helix: a modified Quad helix for correction of bilateral dentoalveolar cross bite.

Standard Quad helix can be used to correct unilateral and bilateral dento alveolar posterior cross bite till first permanent molar. Correcting the second molar cross bite with quad helix is very difficult which requires fixed orthodontic attachment. To overcome this problem we have designed a Penta-V helix- a modified quad helix in correcting bilateral dentoalveolar posterior cross bite up to second molar.

Next generation PhotoCORMs: polynuclear tricarbonylmanganese(I)-functionalized polypyridyl metallodendrimers.

The first CO-releasing metallodendrimers, based on polypyridyl dendritic scaffolds functionalized with Mn(CO)3 moieties, of the general formula [DAB-PPI-{MnBr(bpy(CH3,CH═N))(CO)3}n], where DAB = 1,4-diaminobutane, PPI = poly(propyleneimine), bpy = bipyridyl, and n = 4 for first- or n = 8 for second-generation dendrimers, were synthesized and comprehensively characterized by analytical (HR-ESI mass spectrometry and elemental analysis) and spectroscopic ((1)H, (13)C{(1)H}-NMR, infrared, and UV/vis spectroscopy) methods. The CO-release properties of these compounds were investigated in pure buffer and using the myoglobin assay. Both metallodendrimer generations are stable in the dark in aqueous buffer for up to 16 h but show photoactivated CO release upon excitation at 410 nm, representing a novel class of macromolecular photoactivatable CO-releasing molecules (PhotoCORMs). No scaling effects were observed since both metallodendrimers release ∼65% of the total number of CO ligands per molecule, regardless of the generation number. In addition, the mononuclear model complex [MnBr(bpy(CH3,CH═NCH2CH2CH3))(CO)3] was prepared and comprehensively studied, including DFT/TDDFT calculations. These metallodendrimer-based PhotoCORMs afford new methods of targeted delivery of large amounts of carbon monoxide to cellular systems.

Management of skeletal class III malocclusion treated by manifold approach: 5 year follow-up.

The goal of early treatment of Class III malocclusion isfocused on providing a more favourable environment for normal growth and on improving the psychosocial development of the child by improving the facial appearance. Rapid palatal expansion with maxillary protraction and face mask has provided a predictable and effective approach to managing the treatment. We are presenting a case report of a growing Class III treated using maxillary protraction therapy, (Rapid maxillary expansion using bonded RME appliance, to loosen the nasomaxillary sutures and Petit face mask with bonded occlusal splint to unlock the maxilla). With early intervention, patient compliance is much better, most of them achieving overcorrection in less than a year. Close monitoring and follow up was done for 5 years to ensure stability of the treatment, and there was no relapse tendency.