129 research outputs found

    Flying-seed-like liquid crystals 5: Liquid crystals based on octakisphenylthiophthalocyanine and their optical properties

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    We have synthesized three novel flying-seed-like liquid crystals based on phthalocyaninato copper(II) (abbreviated as PcCu) substituted by bulky groups {(o-C-1)PhS (i), (m-C-1)PhS (j), [m, p(C-1)(2)]PhS (k)} instead of using long alkyl chains, in order to investigate their mesomorphism. Their phase transition behavior and the mesophase structures have been established by using a polarizing optical microscope, a differential scanning calorimeter, and a temperature-dependent small angle X-ray diffractometer. As the results, [(o-C-1)PhS](8)PcCu (8i), [(m-C-1)PhS](8)PcCu (8j) and {[m,p-(C-1)(2)]PhS}(8)PcCu (8k) show a Col tet. o mesophase at 314.9 similar to 362.9 degrees C, a Col(ro) (P2m) mesophase at 287.4 similar to 334.2 degrees C and a Col(ro) (P2m) mesophase at 331.8 similar to 386.8 degrees C, respectively. Very interestingly, each of the derivatives thus exhibits a columnar mesophase at very high temperatures. The mesomorphism is apparently originated from the novel bulky groups (i similar to k). It is also noteworthy that the Q-bands of the present PhScontaining Pc derivatives 8i similar to 8k in THF significantly red-shift by about 35 nm in comparison with those of the corresponding PhO-containing derivatives in THF

    Childhood Stroke: Awareness, Interest, and Knowledge Among the Pediatric Community

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    Objective: Acute childhood stroke is an emergency requiring a high level of awareness among first-line healthcare providers. This survey serves as an indicator of the awareness of, the interest in, and knowledge of childhood stroke of German pediatricians.Methods: Thousand six hundred and ninety-seven physicians of pediatric in- and outpatient facilities in Bavaria, Germany, were invited via email to an online-survey about childhood stroke.Results: The overall participation rate was 14%. Forty-six percent of participants considered a diagnosis of childhood stroke at least once during the past year, and 47% provide care for patients who have suffered childhood stroke. The acronym FAST (Face-Arm-Speech-Time-Test) was correctly cited in 27% of the questionnaires. Most commonly quoted symptoms of childhood stroke were hemiparesis (90%), speech disorder (58%), seizure (44%), headache (40%), and impaired consciousness (33%). Migraine (63%), seizure (39%), and infections of the brain (31%) were most frequently named as stroke mimics. Main diagnostic measures indicated were magnetic resonance imaging (MRI) (96%) and computer tomography (CT) (55%). Main therapeutic strategies were thrombolysis (80%), anticoagulation (41%), neuroprotective measures, and thrombectomies (15% each). Thirty-nine percent of participants had taken part in training sessions, 61% studied literature, 37% discussed with colleagues, and 25% performed internet research on childhood stroke. Ninety-three percent of participants approve skill enhancement, favoring training sessions (80%), publications (43%), and web based offers (35%). Consent for offering a flyer on the topic to caregivers in facilities was given in 49%.Conclusion: Childhood stroke constitutes a topic of clinical importance to pediatricians. Participants demonstrate a considerable level of comprehension concerning the subject, but room for improvement remains. A multi-modal approach encompassing an elaborate training program, regular educational publications in professional journals, and web based offers could reach a broad range of health care providers. Paired with a public adult and childhood stroke awareness campaign, these efforts could contribute to optimize the care for children suffering from stroke

    Enhanced Lifetime Of Excitons In Nonepitaxial Au/cds Core/shell Nanocrystals

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    The ability of metal nanoparticles to capture light through plasmon excitations offers an opportunity for enhancing the optical absorption of plasmon-coupled semiconductor materials via energy transfer. This process, however, requires that the semiconductor component is electrically insulated to prevent a backward charge flow into metal and interfacial states, which causes a premature dissociation of excitons. Here we demonstrate that such an energy exchange can be achieved on the nanoscale by using nonepitaxial Au/CdS core/shell nanocomposites. These materials are fabricated via a multistep cation exchange reaction, which decouples metal and semiconductor phases leading to fewer interfacial defects. Ultrafast transient absorption measurements confirm that the lifetime of excitons in the CdS shell (tau approximate to 300 ps) is much longer than lifetimes of excitons in conventional, reduction-grown Au/CdS heteronanostructures. As a result, the energy of metal nanoparticles can be efficiently utilized by the semiconductor component without undergoing significant nonradiative energy losses, an important property for catalytic or photovoltaic applications. The reduced rate of exciton dissociation in the CdS domain of Au/CdS nanocomposites was attributed to the nonepitaxial nature of Au/CdS interfaces associated with low defect density and a high potential barrier of the interstitial phase

    Sequential targeted exome sequencing of 1001 patients affected by unexplained limb-girdle weakness

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    Several hundred genetic muscle diseases have been described, all of which are rare. Their clinical and genetic heterogeneity means that a genetic diagnosis is challenging. We established an international consortium, MYO-SEQ, to aid the work-ups of muscle disease patients and to better understand disease etiology. Exome sequencing was applied to 1001 undiagnosed patients recruited from more than 40 neuromuscular disease referral centers; standardized phenotypic information was collected for each patient. Exomes were examined for variants in 429 genes associated with muscle conditions. We identified suspected pathogenic variants in 52% of patients across 87 genes. We detected 401 novel variants, 116 of which were recurrent. Variants in CAPN3, DYSF, ANO5, DMD, RYR1, TTN, COL6A2, and SGCA collectively accounted for over half of the solved cases; while variants in newer disease genes, such as BVES and POGLUT1, were also found. The remaining well-characterized unsolved patients (48%) need further investigation. Using our unique infrastructure, we developed a pathway to expedite muscle disease diagnoses. Our data suggest that exome sequencing should be used for pathogenic variant detection in patients with suspected genetic muscle diseases, focusing first on the most common disease genes described here, and subsequently in rarer and newly characterized disease genes

    Administrative Law as the New Federalism

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    An online-system for the evaluation of hazardous substances

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