2,553 research outputs found
Identification of cubebin and epicubebin isolated from Piper cubeba L.f fruits with two D-NMR spectroscopy
One of the isolated active compound of the tracheospasmolytic from kemukus fruits (Piper cubeba L.f) is cubebin. The problem occurred when cubebin (C20H20O6) mixed with its epimer because of the difficultly to identify the structure by 1D-NMR spectroscopy. Structure identification then was conducted by 2D-NMR spectroscopy, so the structure of cubebin and epicubebin can be clear identified.
Key words : Cubebin, epicubebin, identification, 2D-NM
Analisis Faktor – Faktor Yang Mempengaruhi Perilaku Konsumen Terhadap Keputusan Pembelian Di Texas Chicken Manado
Penelitian ini bertujuan untuk mengetahui Faktor Faktor Yang Mempengaruhi Perilaku Konsumen Terhadap Keputusan Pembelian Di Texas Chicken Manado. Penelitian ini menggunakan Metode Analisis Regresi Linear Berganda, Variabel-variabel yang digunakan dalam penelitian ini adalah Budaya (X1) Sosial (X2) Pribadi (X3) Psikologis (X4) yang dihipotesiskan berpengaruh terhadap Keputusan Pembelian (Y). Sampel berjumlah 100 orang dengan metode Purposive Sampel. Instrumen kuesioner digunakan sebagai pengumpul data. Pengujian validitas, reliabilitas atas indikator-indikator dan konsep variabel. Berdasarkan hasil analisis regresi linier berganda secara parsial maupun simultan variabel budaya, social, pribadi dan psikologis berpengaruh positif dan signifikan terhadap Keputusan pembelian di texas chicken manado
The dicistronic RNA from the mouse LINE-1 retrotransposon contains an internal ribosome entry site upstream of each ORF: implications for retrotransposition
Most eukaryotic mRNAs are monocistronic and translated by cap-dependent initiation. LINE-1 RNA is exceptional because it is naturally dicistronic, encoding two proteins essential for retrotransposition, ORF1p and ORF2p. Here, we show that sequences upstream of ORF1 and ORF2 in mouse L1 function as internal ribosome entry sites (IRESes). Deletion analysis of the ORF1 IRES indicates that RNA structure is critical for its function. Conversely, the ORF2 IRES localizes to 53 nt near the 3′ end of ORF1, and appears to depend upon sequence rather than structure. The 40 nt intergenic region (IGR) is not essential for ORF2 IRES function or retrotransposition. Because of strong cis-preference for both proteins during L1 retrotransposition, correct stoichiometry of the two proteins can only be achieved post-transcriptionally. Although the precise stoichiometry is unknown, the retrotransposition intermediate likely contains hundreds of ORF1ps for every ORF2p, together with one L1 RNA. IRES-mediated translation initiation is a well-established mechanism of message-specific regulation, hence, unique mechanisms for the recognition and control of these two IRESes in the L1 RNA could explain differences in translational efficiency of ORF1 and ORF2. In addition, translational regulation may provide an additional layer of control on L1 retrotransposition efficiency, thereby protecting the integrity of the genome
Southwest Pacific Ocean Circulation and Climate Experiment (SPICE) - part I. Scientific background
Strategies to diagnose ovarian cancer: new evidence from phase 3 of the multicentre international IOTA study
Background: To compare different ultrasound-based international ovarian tumour analysis (IOTA) strategies and risk of malignancy index (RMI) for ovarian cancer diagnosis using a meta-analysis approach of centre-specific data from IOTA3. Methods: This prospective multicentre diagnostic accuracy study included 2403 patients with 1423 benign and 980 malignant adnexal masses from 2009 until 2012. All patients underwent standardised transvaginal ultrasonography. Test performance of RMI, subjective assessment (SA) of ultrasound findings, two IOTA risk models (LR1 and LR2), and strategies involving combinations of IOTA simple rules (SRs), simple descriptors (SDs) and LR2 with and without SA was estimated using a meta-analysis approach. Reference standard was histology after surgery. Results: The areas under the receiver operator characteristic curves of LR1, LR2, SA and RMI were 0.930 (0.917–0.942), 0.918 (0.905–0.930), 0.914 (0.886–0.936) and 0.875 (0.853–0.894). Diagnostic one-step and two-step strategies using LR1, LR2, SR and SD achieved summary estimates for sensitivity 90–96%, specificity 74–79% and diagnostic odds ratio (DOR) 32.8–50.5. Adding SA when IOTA methods yielded equivocal results improved performance (DOR 57.6–75.7). Risk of Malignancy Index had sensitivity 67%, specificity 91% and DOR 17.5. Conclusions: This study shows all IOTA strategies had excellent diagnostic performance in comparison with RMI. The IOTA strategy chosen may be determined by clinical preference
The Use of Animal Models to Study Bacterial Translocation During Acute Pancreatitis
Infection of pancreatic necrosis with intestinal flora is accepted to be a main predictor of outcome during severe acute pancreatitis. Bacterial translocation is the process whereby luminal bacteria migrate to extraintestinal sites. Animal models were proven indispensable in detecting three major aspects of bacterial translocation: small bowel bacterial overgrowth, mucosal barrier failure, and disturbed immune responses. Despite the progress made in the knowledge of bacterial translocation, the exact mechanism, origin and route of bacteria, and the optimal prophylactic and treatment strategies remain unclear. Methodological restrictions of animal models are likely to be the cause of this uncertainty. A literature review of animal models used to study bacterial translocation during acute pancreatitis demonstrates that many experimental techniques per se interfere with intestinal flora, mucosal barrier function, or immune response. Interference with these major aspects of bacterial translocation complicates interpretation of study results. This paper addresses these and other issues of animal models most frequently used to study bacterial translocation during acute pancreatitis
Measuring cavity powers of active galactic nuclei in clusters using a hybrid X-ray–radio method. A new window on feedback opened by subarcsecond LOFAR-VLBI observations
Measurements of the quantity of radio-mode feedback injected by an active galactic nucleus into the cluster environment have mostly
relied on X-ray observations, which reveal cavities in the intracluster medium excavated by the radio lobes. However, the sensitivity
required to accurately constrain the dimensions of these cavities has proven to be a major limiting factor and is the main bottleneck
on high-redshift measurements. We describe a hybrid method based on a combination of X-ray and radio observations, which aims to
enhance our ability to study radio-mode feedback. In this paper, we present one of the first samples of galaxy clusters observed with
the International LOFAR Telescope (ILT) at 144 MHz and use this sample to test the hybrid method at lower frequencies than before.
By comparing our measurements with results found in literature based on the traditional method using only X-ray observations, we
find that the hybrid method provides consistent results to the traditional method. In addition, we find that the correlation between the
traditional method and the hybrid method improves as the X-ray cavities are more clearly defined. This suggests that using radio lobes
as proxies for cavities may help to circumvent systematic uncertainties in the cavity volume measurements. Encouraged by the high
volume of unique ILT observations successfully processed, this hybrid method enables radio-mode feedback to be studied at high
redshifts for the first time even for large samples of clusters
Visualisation and characterisation of flame radical emissions through intensified spectroscopic imaging
Combustion flames contain strong emissions from excited radical species produced by the combustion process. The monitoring and characterisation of such emissions is important for an in-depth understanding of fuel energy conversion and pollutant formation processes. In this paper, an approach combining emission spectroscopy with intensified digital imaging techniques is proposed for visualising and quantifying the radiative characteristics of free radicals of combustion flames. Recent advances in CCD technology, especially in EM image intensification, have made it possible to obtain high resolution emission images of isolated spectral emissions from particular flame radicals. These can be used to study emission intensity
and distribution, with the aim of correlating combustion emission products with flame spectral emission patterns
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