1,720,963 research outputs found
Penetapan Kadar Rutin Pada Ekstrak Etanol Daun Binahong Dengan Metode Kromatografi Cair Kinerja Tinggi
Full text linkIn Silico Study of Kaempferol Targeting MMPs and COX-2 for Anti-Aging and Wound Healing
Full text linkSkin aging and impaired wound healing are complex biological processes involving chronic inflammation and excessive degradation of the extracellular matrix. Matrix metalloproteinases (MMP-1, MMP-3, and MMP-9) and cyclooxygenase-2 (COX-2) play crucial roles in these processes and are considered important molecular targets for anti-aging and wound healing therapies. Kaempferol is a natural flavonoid compound known for its antioxidant and anti-inflammatory activities; however, its molecular interaction mechanisms with these targets remain incompletely understood. This study aimed to evaluate the potential of kaempferol as an anti-aging and wound healing agent through a molecular docking approach targeting MMP-1, MMP-3, MMP-9, and COX-2. Molecular docking simulations were performed using Molegro Virtual Docker 6.0, while ligand-protein interactions were visualized and analyzed using BIOVIA Discovery Studio Visualizer v.21.1.0.20298. The docking results indicated that kaempferol exhibited favorable binding affinities toward all target proteins, with the strongest interactions observed for MMP-9 and COX-2. Kaempferol formed conventional hydrogen bonds as well as hydrophobic and aromatic interactions within the active sites of the proteins. In conclusion, kaempferol demonstrates potential as a multitarget natural compound for anti-aging and wound healing applications, although further in vitro and in vivo studies are required to validate its biological activity
Development of Chemometric Methods for Determining Caffeine Content in Robusta Coffee as Alternative Standardization Techniques
Full text linkThere is a necessity for standardization to uphold coffee quality due to its frequent production and consumption. High-performance liquid chromatography (HPLC) serves as the benchmark for caffeine analysis in coffee in Indonesia. However, its high cost has prompted the exploration of alternative methods. This study aims to obtain a suitable alternative method for determining the caffeine content in robusta coffee as an effort toward standardization. Employing statistical and mathematical techniques in chemistry, chemometrics emerges as a promising alternative in analyzing caffeine in coffee. The approach was integrated with an ultraviolet (UV) spectrophotometer capable of analyzing substances across wavelengths from 200 to 400 nm. From the five replications, the HPLC method showed a caffeine content of 1.435 ± 0.011% (w/w), while the spectrophotometer showed a content of 1.723 ± 0.003% (w/w). Through the partial least squares regression (PLSR) and principal component regression (PCR) methods in RStudio, the results obtained were 1.432 ± 0.003% and 1.430 ± 0.002% (w/w), respectively. These results indicate good REP values of 0.022% for PLSR and 0.155% for PCR. With these findings, it is hoped that chemometrics can become an alternative method for analyzing caffeine in coffee
Development and Method Validation of HPLC Method as an Key Method in the Analysis of Olopatadine HCl
No full textOlopatadine hydrochloride (HCl) is a widely used second-generation antihistamine, and its accurate quantification is critical to ensure product quality and therapeutic efficacy. Reliable analytical methods are therefore essential for regulatory compliance and routine quality control. This study aimed to develop and validate a simple and robust high-performance liquid chromatography (HPLC) method for the determination of olopatadine HCl in pharmaceutical samples. The method was validated in accordance with USP <1225>, AOAC, and ICH Q2(R1) guidelines, with evaluation of key parameters including linearity, accuracy, precision, selectivity, sensitivity, and system suitability. The validation outcomes confirmed that the method provided strong linearity across the tested range, acceptable recovery values, excellent repeatability, and sufficient sensitivity for low-level detection. Overall, the developed HPLC method proved to be accurate, precise, selective, and reliable. Its simplicity and cost-effectiveness make it particularly suitable for routine quality control of olopatadine HCl in research and pharmaceutical industry laboratories
Validasi Metode dan Penetapan Kadar Olopatadine HCl Pada Obat Tetes Mata Menggunakan Spektrofotometer UV
Full text linkOlopatadin HCl merupakan antihistamin generasi kedua dengan mekanisme kerja ganda, yaitu antagonis selektif reseptor histamin H₁ dan stabilisasi membran sel mast, yang efektif untuk terapi alergi seperti konjungtivitis dan rinitis alergi. Penelitian ini bertujuan memvalidasi metode spektrofotometri UV–Vis untuk penetapan kadar olopatadin HCl dalam sediaan obat tetes mata yang beredar di Indonesia. Metode dikembangkan dengan larutan standar pada rentang konsentrasi 20–80 ppm, penentuan panjang gelombang maksimum, serta pengujian parameter validasi meliputi linearitas, akurasi, presisi, dan sensitivitas. Hasil menunjukkan panjang gelombang optimum pada 299 nm dengan persamaan regresi y = 25262x + 91851 (r = 0,99). Nilai perolehan kembali sebesar 105,63% dan koefisien variasi 0,52% memenuhi kriteria AOAC, sedangkan batas deteksi (LOD) dan batas kuantifikasi (LOQ) masing-masing sebesar 0,05 ppm dan 0,16 ppm. Kadar olopatadin HCl dalam sampel diperoleh sebesar 0,095 ± 0,001%. Metode ini terbukti sederhana, ekonomis, dan andal, sehingga layak diterapkan untuk pengendalian mutu rutin di laboratorium penelitian maupun industri farmasi
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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