3,944 research outputs found

    Homo- and Heteroleptic Copper(I) Complexes with Diazabutadiene Ligands: Synthesis, Solution- and Solid-State Structural Studies

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    The preparation of novel copper(I) complexes of diazabutadiene (DAB) ligands with aliphatic backbones is reported. [Cu(DABR)2](BF4), [Cu(DABR)(NCMe)2](BF4) and [CuCl(DABR)] are easily synthesised and air-stable. These complexes, which remain scarce in the literature, have been fully characterised, and their behaviour both in the solid state as well as in solution has been studied by means of X-ray crystallography, NMR and UV/Vis spectroscopy

    Implementasi Pandas Data frame sebagai Agregasi dan Tabulasi Penyajian Data Luaran Survei Kepuasan Pengguna Proses Pembelajaran dalam Pendidikan Tinggi

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    Pandas (Python Data Analysis) merupakan pustaka pengolahan data dengan domain pemrograman python. Pustaka tersebut memiliki fitur data frame yang dapat membantu dalam manajemen data berbasis tabel atau informasi larik (array). Agregasi data dengan sumber luaran kegiatan survei kepuasan pengguna proses pembelajaran dalam pendidikan tinggi memiliki perekaman data sekitar 8800 baris. Rekaman data tersebut tersaji dalam file comma-separated values dengan isi parameter adalah objek dan butir penilaian. Penelitian ini bertujuan untuk melakukan agregasi dan penyusunan data tak terstruktur menjadi untaian data tabular sehingga memudahkan dalam penyajian informasi. Penelitian ini terdapat dua metode secara umum yaitu pengelompokan rekaman data dan penyajian data dalam tabel pivot. Pegelompokan data dilakukan dengan melihat indeks pengelompokan dan matrik nilai survei. Data yang tak terstruktur akan menjadi data utuh dengan pengelompokan berdasarkan indeks. Proses kedua setelah tahap pengelompokan adalah penyajian data dalam tabel pivot. Proses pivot dilakukan dengan transformasi matrik berpasangan untuk menjaga konsistensi isi data. Proses komputasi digunakan untuk membantu penyusunan data yang bersifat ganda dalam data frame tak terstruktur. Proses konfigurasi informasi secara otomatis dilakukan secara mandiri dari source code yang telah dibuat dengan beberapa kekangan informasi. Hasil luaran informasi dari seluruh proses pengolahan data frame adalah tabel pivot yang berisikan informasi pasangan objek dan nilai survei. Objek survei yang merupakan ID dari pengajar akan dipasangkan dengan butir penilaian oleh responden, yang nantinya informasi tersebut digunakan sebagai bahan analisis kualitatif kepuasan pengguna. Validasi dilakukan dengan mencocokan hasil penyajian data pivot dengan sumber data. Akurasi komputasi memiliki nilai 92.4% yang terhitung dari 50 titik uji dari matrik data. Waktu komputasi dari proses pengelompokan hingga penyajian data adalah 3-4 detik dengan jumlah data adalah 8800 baris. Komparasi runtime komputasi memiliki efisiensi yang cukup tinggi dalam penyajian data survei jika dibandingkan dengan penyajian data secara manual menggunakan Microsoft office

    DACUM: A National Database Justifying the Study of Speech Communication

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    This article proposes that Developing A Curriculum (DACUM), a standardized curriculum development process, be tapped to justify the study of speech communication in higher education. DACUM is a standardized method for determining curricular needs. Its purpose is to identify the duties, tasks and skills performed in a particular occupation, career area or profession. DACUM assumes that successful workers are best equipped to identify the competencies needed in their specific occupation. DACUM was created by he Canada Department of Manpower and Immigration and the General Learning Corp. of New York

    Wall slip and flow of concentrated hard-sphere colloidal suspensions

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    We present a comprehensive study of the slip and flow of concentrated colloidal suspensions using cone-plate rheometry and simultaneous confocal imaging. In the colloidal glass regime, for smooth, non-stick walls, the solid nature of the suspension causes a transition in the rheology from Herschel-Bulkley (HB) bulk flow behavior at large stress to a Bingham-like slip behavior at low stress, which is suppressed for sufficient colloid-wall attraction or colloid-scale wall roughness. Visualization shows how the slip-shear transition depends on gap size and the boundary conditions at both walls and that partial slip persist well above the yield stress. A phenomenological model, incorporating the Bingham slip law and HB bulk flow, fully accounts for the behavior. Microscopically, the Bingham law is related to a thin (sub-colloidal) lubrication layer at the wall, giving rise to a characteristic dependence of slip parameters on particle size and concentration. We relate this to the suspension's osmotic pressure and yield stress and also analyze the influence of van der Waals interaction. For the largest concentrations, we observe non-uniform flow around the yield stress, in line with recent work on bulk shear-banding of concentrated pastes. We also describe residual slip in concentrated liquid suspensions, where the vanishing yield stress causes coexistence of (weak) slip and bulk shear flow for all measured rates

    Emergence of visually-evoked reward expectation signals in dopamine neurons via the superior colliculus in V1 lesioned monkeys

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    Responses of midbrain dopamine (DA) neurons reflecting expected reward from sensory cues are critical for reward-based associative learning. However, critical pathways by which reward-related visual information is relayed to DA neurons remain unclear. To address this question, we investigated Pavlovian conditioning in macaque monkeys with unilateral primary visual cortex (V1) lesions (an animal model of 'blindsight'). Anticipatory licking responses to obtain juice drops were elicited in response to visual conditioned stimuli (CS) in the affected visual field. Subsequent pharmacological inactivation of the superior colliculus (SC) suppressed the anticipatory licking. Concurrent single unit recordings indicated that DA responses reflecting the reward expectation could be recorded in the absence of V1, and that these responses were also suppressed by SC inactivation. These results indicate that the subcortical visual circuit can relay reward-predicting visual information to DA neurons and integrity of the SC is necessary for visually-elicited classically conditioned responses after V1 lesion

    The Incidence and Clinical Relevance of Graft Hypertrophy After Matrix-Based Autologous Chondrocyte Implantation

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    Background: Graft hypertrophy is the most common complication of periosteal autologous chondrocyte implantation (p-ACI). Purpose: The aim of this prospective study was to analyze the development, the incidence rate, and the persistence of graft hypertrophy after matrix-based autologous chondrocyte implantation (mb-ACI) in the knee joint within a 2-year postoperative course. Study Design: Case series; Level of evidence, 4. Methods: Between 2004 and 2007, a total of 41 patients with 44 isolated cartilage defects of the knee were treated with the mb-ACI technique. The mean age of the patients was 35.8 years (standard deviation [SD], 11.3 years), and the mean body mass index was 25.9 (SD, 4.2; range, 19-35.3). The cartilage defects were arthroscopically classified as Outerbridge grades III and IV. The mean area of the cartilage defect measured 6.14 cm2 (SD, 2.3 cm2). Postoperative clinical and magnetic resonance imaging (MRI) examinations were conducted at 3, 6, 12, and 24 months to analyze the incidence and course of the graft. Results: Graft hypertrophy developed in 25% of the patients treated with mb-ACI within a postoperative course of 1 year; 16% of the patients developed hypertrophy grade 2, and 9% developed hypertrophy grade 1. Graft hypertrophy occurred primarily in the first 12 months and regressed in most cases within 2 years. The International Knee Documentation Committee (IKDC) and visual analog scale (VAS) scores improved during the postoperative follow-up time of 2 years. There was no difference between the clinical results regarding the IKDC and VAS pain scores and the presence of graft hypertrophy. Conclusion: The mb-ACI technique does not lead to graft hypertrophy requiring treatment as opposed to classic p-ACI. The frequency of occurrence of graft hypertrophy after p-ACI and mb-ACI is comparable. Graft hypertrophy can be considered as a temporary excessive growth of regenerative cartilage tissue rather than a true graft hypertrophy. It is therefore usually not a persistent or systematic complication in the treatment of circumscribed cartilage defects with mb-ACI
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