Significant enhancement of irreversibility field in clean-limit bulk MgB2

Low resistivity ("clean") MgB2 bulk samples annealed in Mg vapor show an increase in upper critical field Hc2(T) and irreversibility field Hirr(T) by a factor of 2 in both transport and magnetic measurements. The best sample displayed Hirr above 14 T at 4.2 K and 6 T at 20 K. These changes were accompanied by an increase of the 40 K resistivity from 1.0 to 18 microohm-cm and a lowering of the resistivity ratio from 15 to 3, while the critical temperature Tc decreased by only 1-2 K. These results point the way to make prepare MgB2 attractive for magnet applications.Comment: 3 pages, 4 figures, submitted to Applied Physics Letter

Kualitas Pelayanan Frontliner dan Kepuasan Nasabah

Penelitian ini bertujuan untuk menguji pengaruhkualitas pelayanan frontliner dengan kepuasan nasabah padaPT. Bank Syariah Mandiri Cabang Cikupa dan seberapasignifikan keadaan pengaruh tersebut. Penelitian inimenggunakan metode kuesioner/angket dan observasi.Kuesioner/angket digunakan untuk memperoleh data tentangkarakteristik responden yaitu nasabah dan untuk memperolehdata tentang pengaruh kualitas pelayanan frontliner dengankepuasan nasabah pada PT. Bank Syariah Mandiri CabangCikupa melalui pernyataan/pertanyaan dalamkuesioner/angket tersebut. Sedangkan observasi digunakanuntuk pengamatan langsung tempat penelitian serta mengalidata tentang strukstur organisasi, populasi dan sampel. Hasilpenelitian menunjukkan bahwa persepsi responden terhadapkualitas pelayanan frontliner dalam kategori cukup baik danterhadap kepuasan nasabah dalam kategori cukup puas

CHALLENGES IN FORMULATING HERBAL COSMETICS

The herbal cosmetics are prepared by phytochemicals that occur in a variety of botanical sources, that influences the physiology of skin and provide nutrients that are necessary for the healthy skin or hair. These products are utilized for daily purposes, which include herbal shampoo, herbal conditioner, herbal face wash, herbal soap, etc. These products are classified as a different category by regulatory agencies. However, guidelines of these certifying agencies have no harmonization, and many cosmetic industries prepare and package these formulations in an irrationalway. Many cosmetic products have natural products in their formulation that perform a specific biological function, but these products should be evaluated on their toxicological and efficacy aspects. The contribution of developing countries is very poor in global herbal business because of lack of standardization measures and quality control. The lack of safety and efficacy data on herbal cosmetics renders it difficult to meet the criteria needed for supporting its use worldwide. This review article discusses challenges related to regulatory status, quality control, standardization, certification, drug processing and the opportunities for herbal cosmetics in local as well as the global scenario. The search criteria used in the present review were the keywords mentioned in the manuscript and articles from major scientific resources were cited. The articles from 1952 to 2018 were specifically referred, but few references from 19 century were also cited to support the prevalence of scientific principles in the development of herbal cosmetics in the ancient era

Distinguishing alpha1-antitrypsin deficiency from asthma

AbstractObjectiveTo explore the relations that exist between α1-antitrypsin deficiency (AATD) and asthma and to evaluate practices for screening patients with asthma for this genetically determined condition in the context of current guidelines.Data SourcesEnglish-language articles were selected from a PubMed search using combinations of the following search terms: alpha1-antitrypsin, screening, and asthma.Study SelectionsStudies to be included in this review were based on the authors' expert opinions.ResultsAsthma and AATD are 2 distinct conditions yet they can coexist. Although AATD has a variable symptomatology and some patients may be asymptomatic, many can present with symptoms that are similar to those of asthma, such as dyspnea, wheezing, cough, and mucus production, which can cause confusion at diagnosis. A simple genetic test exists for AATD, which is a single-gene disorder, and the American Thoracic Society and European Respiratory Society guidelines recommend the screening of patients with asthma who exhibit chronic airflow obstruction. Patients with AATD are seen by internal medicine, family medicine, allergy, and pulmonary clinicians, yet there is a generalized lack of awareness of testing among all specialties. This leads to a delayed diagnosis for patients with AATD, typically by 8.3 years.ConclusionA greater awareness of AATD among clinicians who regularly manage patients with asthma symptoms could increase diagnosis rates, thus optimizing interventions and management strategies to improve patient outcomes

Cu_{2}O as nonmagnetic semiconductor for spin transport in crystalline oxide electronics

We probe spin transport in Cu_{2}O by measuring spin valve effect in La_{0.7}Sr_{0.3}MnO_{3}/Cu_{2}O/Co and La_{0.7}Sr_{0.3}MnO_{3}/Cu_{2}O/La_{0.7}Sr_{0.3}MnO_{3} epitaxial heterostructures. In La_{0.7}Sr_{0.3}MnO_{3}/Cu_{2}O/Co systems we find that a fraction of out-of-equilibrium spin polarized carrier actually travel across the Cu_{2}O layer up to distances of almost 100 nm at low temperature. The corresponding spin diffusion length dspin is estimated around 40 nm. Furthermore, we find that the insertion of a SrTiO_{3} tunneling barrier does not improve spin injection, likely due to the matching of resistances at the interfaces. Our result on dspin may be likely improved, both in terms of Cu_{2}O crystalline quality and sub-micrometric morphology and in terms of device geometry, indicating that Cu_{2}O is a potential material for efficient spin transport in devices based on crystalline oxides.Comment: 15 pages, 10 figure

The Crossover beteween Aslamazov-Larkin and Short Wavelength Fluctuations Regimes in HTS Conductivity Experiments

We present paraconductivity (AL) measurements in three different high temperature superconductors: a melt textured $YBa_2Cu_3O_7$ sample, a $Bi_2Sr_2CaCu_2O_8$ epitaxial thin film and a highly textured $Bi_2Sr_2Ca_2Cu_3O_{10}$ tape. The crossovers between different temperature regimes in excess conductivity have been analysed. The Lawrence-Doniach (LD) crossover, which separates the 2D and 3D regimes, shifts from lower to higher temperatures as the compound anisotropy decreases. Once the LD crossover is overcome, the fluctuation conductivity of the three compounds shows the same universal behaviour: for $\epsilon =\ln T/T_c > 0.23$ all the curves bend down according to the $1/\epsilon^3$ law. This asymptotic behaviour was theoretically predicted previously for the high temperature region where the short wavelength fluctuations (SWF) become important.Comment: 4 pages, Revtex, 1 PostScript figure available upon request ([email protected]); submitted to Physical Review B rapid communication

High binding yet accelerated guest rotation within a cucurbit[7]uril complex. Toward paramagnetic gyroscopes and rolling nanomachines †

International audienceThe (15-oxo-3,7,11-triazadispiro[5.1.5.3]hexadec-7-yl)oxidanyl, a bis-spiropiperidinium nitroxide derived from TEMPONE, can be included in cucurbit[7]uril to form a strong (K a ∼ 2 × 10 5 M −1) CB[7]@bPTO complex. EPR and MS spectra, DFT calculations, and unparalleled increased resistance (a factor of ∼10 3) toward ascorbic acid reduction show evidence of deep inclusion of bPTO inside CB[7]. The unusual shape of the CB[7]@bPTO EPR spectrum can be explained by an anisotropic Brownian rotational diffusion, the global tumbling of the complex being slower than rotation of bPTO around its " long molecular axis " inside CB[7]. The CB[7] (stator) with the encapsulated bPTO (rotator) behaves as a supramolecular para-magnetic rotor with increased rotational speed of the rotator that has great potential for advanced nano-scale machines requiring wheels such as cucurbiturils with virtually no friction between the wheel and the axle for optimum wheel rotation (i.e. nanopulleys and nanocars)