Ein einfaches Verfahren zur Herstellung anellierter Thiophene

A simple method for the synthesis of fused thiophenes by reaction of agr-carboxymethyl substituted cyclic ketones withLawesson-reagent is described. Considerations concerning the reaction mechanism are given

A rapidly-reversible absorptive and emissive vapochromic Pt(II) pincer-based chemical sensor

Selective, robust and cost-effective chemical sensors for detecting small volatile-organic compounds (VOCs) have widespread applications in industry, healthcare and environmental monitoring. Here we design a Pt(II) pincer-type material with selective absorptive and emissive responses to methanol and water. The yellow anhydrous form converts reversibly on a subsecond timescale to a red hydrate in the presence of parts-per-thousand levels of atmospheric water vapour. Exposure to methanol induces a similarly-rapid and reversible colour change to a blue methanol solvate. Stable smart coatings on glass demonstrate robust switching over 104 cycles, and flexible microporous polymer membranes incorporating microcrystals of the complex show identical vapochromic behaviour. The rapid vapochromic response can be rationalised from the crystal structure, and in combination with quantum-chemical modelling, we provide a complete microscopic picture of the switching mechanism. We discuss how this multiscale design approach can be used to obtain new compounds with tailored VOC selectivity and spectral responses

Comparison of DLK incidence after laser in situ keratomileusis associated with two femtosecond lasers: Femto LDV and IntraLase FS60

Minoru Tomita,1&ndash;3 Yuko Sotoyama,1 Satoshi Yukawa,1 Tadayuki Nakamura1 1Shinagawa LASIK Center, Chiyoda-ku, Tokyo, Japan; 2Department of Ophthalmology, Wenzhou Medical College, Wenzhou, People&rsquo;s Republic of China; 3Eye Can Cataract Surgery Center, Manila, Philippines Purpose: To compare the incidence of diffuse lamellar keratitis (DLK) after laser in situ keratomileusis (LASIK) with flap creation using the Femto LDV and IntraLase&trade; FS60 femtosecond lasers. Methods: A total of 818 consecutive myopic eyes had LASIK performed using either Femto LDV or IntraLase FS60 for flap creation. The same excimer laser, the Allegretto Wave&reg; Eye-Q Laser, was used for correcting refractive errors for all patients. In the preoperative examination, uncorrected distance visual acuity, corrected distance visual acuity, and manifest refraction spherical equivalent were measured. At the postop examination, the same examinations were performed along with a slit-lamp biomicroscopic examination, and patients with DLK were classified into stages. For the statistical analysis of the DLK occurrence rate and the visual and refractive outcomes, the Mann-Whitney&rsquo;s U-test was used. Results: In the Femto LDV group with 514 eyes, 42 (8.17%) had DLK. In the IntraLase FS60 group with 304 eyes, 114 (37.5%) had DLK. There was a statistically significant difference in the DLK incidence rate between these groups (P < 0.0001). Both groups had excellent visual and refractive outcomes. Although low levels of DLK were observed for both groups, they did not affect visual acuity. Conclusion: While there were significantly fewer incidences of low level DLK when using Femto LDV, neither femtosecond laser induced high levels of DLK, and any postoperative DLK cleared up within 1 week. Therefore, both lasers provide excellent results, with no clinical differences, and both excel at flap creation for LASIK. Keywords: LASIK, Ziemer, Femto LDV, DLK, IntraLase FS60, femtosecond lase

Evaluating the different laser fragmentation patterns used in laser cataract surgeries in terms of effective phacoemulsification time and power

Tukezban Huseynova,1 Mariko Mita,2 Christine Carole C Corpuz,1 Yuko Sotoyama,1 Minoru Tomita2,3 1Shinagawa LASIK Center, Tokyo, Japan; 2Tomita Minoru Eye Clinic Ginza, Tokyo, Japan; 3Wenzhou Medical College, Wenzhou, People&rsquo;s Republic of China Purpose: To evaluate the effects of the different fragmentation patterns for the lens nucleus in terms of the effective phacoemulsification time (EPT) and power. Setting: Shinagawa LASIK Center, Tokyo, Japan. Design: Comparison study. Methods: Seventy-one eyes of 71&nbsp;patients had preoperative lens opacity grading based on the Emery-Little Classification (Grade 1&nbsp;and Grade 2). Eyes underwent femtosecond laser-assisted cataract surgery (Catalys&trade; Precision Laser System), for capsulotomy and lens fragmentation. For the lens fragmentation, either the quadrants softened (Quadrant) or the quadrants complete (Complete) pattern was used. The mean EPT and phacoemulsification (phaco) power for each cutting pattern of Grades 1&nbsp;and 2&nbsp;cataracts were evaluated. Results: The mean EPT was 28.96&nbsp;seconds in the Quadrant Group and 16.31&nbsp;seconds in the Complete Group (P=0.006). The mean phaco power was 8.07% in the Quadrant Group and 4.77% in the Complete Group (P=0.0002). Comparing the Quadrant and Complete Groups of Grade 1&nbsp;cataract showed no significant difference in EPT (P=0.16), but showed a significant difference in phaco power (P=0.033). Comparing the Quadrant and Complete patterns of Grade 2&nbsp;cataract showed significant differences in both EPT (P=0.012) and phaco power (P=0.003). Using the Complete pattern showed a 44.7% reduction in EPT and a 40.9% reduction in phaco power when compared to the Quadrant Group. Conclusion: Using the smaller fragmentation pattern in femtosecond laser cataract surgery, the phaco time and power were reduced significantly when compared to the procedure with the larger fragmentation pattern. Keywords: effective phacoemulsification time (EPT), complete and quadrant fragmentation patter

Key Factors in Membrane Emulsification

In contrast to widely used emulsification processes (high pressure homogenizers, rotor/ stator, etc.), emulsions can be made with mineral membranes in relatively low and controlled shear conditions. In this system, the dispersed phase permeates through membrane pores into the continuous phase circulating in the retentate loop. Droplets detach from the membrane owing to the shearing of the continuous phase. This process produces only a little heating, energy consumption is low. This is interesting both from economic and technological points of view, because it may limit the denaturation of macromolecular emulsifiers. The influence of some factors (membranes, working conditions, emulsifiers) on the droplet size of oil-water emulsions was studied. The sizes depended mainly on the adsorption speed of emulsifiers: emulsions were much finer with emulsifiers adsorbing quickly at the interface, such as SDS (sodium dodecyl sulfate) than with emulsifiers lowering the interfacial tension more slowly, such as β-casein or 11S soya globulin. The membrane pore size, the shear rate at the membrane surface and, to a lesser extent, the volume fraction of the oil phase (between 0 and 30%) had also a significant effect, unlike the oil flux. The emulsions were finer and more stable than those obtained in the same conditions with a rotor/stator system