1,720,956 research outputs found
Studi Komprehensif Ulva Sp. dan Cladophora Sp. : Identifikasi, Keragaman Metabolik, Aktivitas Antibakteri, dan Potensi Nutrasetikal
Get PDFMakroalga merupakan organisme autotrof yang memiliki potensi bioaktif, yang dapat dimanfaatkan dalam bidang farmasi dan industri makanan. Penelitian ini berfokus pada Ulva sp. dan Cladophora sp., dua makroalga yang memiliki keragaman metabolik serta senyawa bioaktif yang berpotensi dalam nutraseutikal. Penelitian ini bertujuan untuk mengidentifikasi karakteristik morfologis dan genetik, mengidentifikasi komponen utama dalam profil metabolik, mengeksplorasi senyawa antibakteri, serta mengevaluasi potensi nutraseutikal dari Ulva sp. dan Cladophora sp. yang dikumpulkan dari tiga pantai berbeda dengan dua metode ekstraksi dan empat jenis pelarut. Metode penelitian yang digunakan mencakup observasi dan eksperimen. Hasil penelitian mengidentifikasi Ulva sp. dengan kode sampel PS.CH1.BSA dan PK.CH1.BSA yang memiliki kemiripan dengan spesies Ulva lactuca isolate D3047 dengan nilai similaritas 96,73% dan 97,19%. Senyawa bioaktif yang teridentifikasi sebagai antibakteri dan nutraseutikal meliputi apratoxin A, 7-Dehydrocholesterol, cholest-5-en-3-ol, deoxycholic acid, diisooctyl phthalate, neomycin sulfate, neoeriocitrin, n-pentyloctadecanamide, ouabain, pheophorbide A, porphyra-334, raffinose, rutin, dan sarmentoside B. Uji aktivitas antibakteri menunjukkan bahwa Ulva sp. dan Cladophora sp. memiliki aktivitas antibakteri dengan kategori resistant. Aktivitas antibakteri terhadap bakteri E. coli K12 menunjukkan nilai tertinggi pada Ulva sp. dan Cladophora sp. masing-masing sebesar 1,37 mm dan 2,27 mm. Aktivitas antibakteri terhadap bakteri M. luteus ATCC4698 menunjukkan nilai tertinggi pada Ulva sp. dan Cladophora sp. masing-masing sebesar 3,10 mm dan 3,38 mm. Aktivitas antibakteri terhadap bakteri B. megaterium DSM32 menunjukkan nilai tertinggi pada Ulva sp. dan Cladophora sp. masing-masing sebesar 1,30 mm dan 1,33 mm. Senyawa-senyawa yang teridentifikasi memiliki potensi sebagai agen antibakteri serta nutraseutikal, termasuk dalam aplikasi terapeutik, antiinflamasi, antioksidan, antimikroba, antikanker, dan lainnya
Potensi Senyawa Bioaktif dari Makroalga Hijau: Eksplorasi dan Implementasinya dalam Aplikasi Industri (Studi pada Ulvan)
Get PDFThe marine ecosystem harbors a wealth of natural resources that can be transformed into high-value products, with green algae, particularly ulvan, being the focus of research. Ulvan, a unique sulfated polysaccharide from green macroalgae, offers potential as a bioactive compound with various activities. Chemical structure analysis of ulvan reveals its potential applications in the industry. Ulvan extraction techniques are critical steps in achieving optimal yields, while separation and characterization of ulvan fractions through chromatography and spectroscopy allow for the identification of specific compounds. Experiments indicate that ulvan possesses strong antioxidant activity, supporting its role in functional food formulations and nutraceutical supplements. In the pharmaceutical industry, ulvan is used in the development of anti-tumor drugs and immunostimulants, with clinical trials showing positive effects on immune responses and inhibition of tumor cell growth. In the cosmetic field, formulations containing ulvan demonstrate anti-aging effects and skin hydration. The application of ulvan in biotechnology involves the production of biomaterials and biofuels. The conversion of ulvan into biofuel through microbial fermentation shows potential as a renewable energy source. Ulvan is also utilized in the production of biomaterials for medical applications, such as wound dressings. Exploring the potential anti-hyperglycemic properties of ulvan opens opportunities for diabetes therapy. Challenges related to ulvan production efficiency and in-depth characterization need to be addressed. A profound understanding of ulvan's potential as a sustainable natural resource is expected to stimulate innovation across various industrial sectors. This research provides a comprehensive overview of natural resources that can shape the future of sustainable and environmentally friendly product
KOMUNIKASI SINGKAT: KEBIASAAN MAKAN IKAN KEPALA TIMAH (Aplocheilus panchax, Hamilton 1822) DI PERAIRAN EKSTREM ASAM PASCATAMBANG TIMAH TERABAIKAN
Get PDFKepala Timah (Aplocheilus panchax, Hamilton 1822) is one of the fish that has the survival abilities to live in a wide variety of quality waters. The ability of A. panchax to survive in acidic waters has begun to be widely studied as extremophile fish to study ecosystems in aquatic habitats that have acidic characteristics. This study aimed to determine the food habits of A. panchax as natural food in acid water of abandoned ex-tin mining activity. The results showed that the natural food for A. panchax was insects larvae or insects that fall on the surface of the waters. The food habits and terminal mouth type confirmed that A. panchax was surface feeder fish, carnivorous fish, larvivorous or insectivorous fish. The sagittiform body type was used A. panchax to did the strategy of feeding behavior by pursue or ambush their prey and it indicated that A. panchax as ambush predator
Agen Biologis Bioremediasi Logam Berat (Heavy Metal Bioremediation Biologycal Agents)
No full textEnvironmental pollution from hazardous waste materials, organic pollutants and heavy metals has had a negative impact on natural ecosystems to the detriment of humans. These pollutants arise from anthropogenic sources as well as natural disasters such as hurricanes and volcanic eruptions. Toxic metals can accumulate in agricultural land and enter the food chain, thus becoming a major threat to food security. Conventional and physical methods are expensive and ineffective in areas of low metal toxicity. Therefore, bioremediation is an environmentally friendly and efficient method of reclamation of heavy metal contaminated environments by utilizing biological mechanisms inherent in bacteria, fungi, algae and plants to eradicate harmful contaminants. This review discusses the elimination of heavy metal pollution carried out by bacteria, fungi, algae & plants through extracellular and intracellular mechanisms. Heavy metal bioremediation activities are not only focused on economic aspects, but must be integrated, efficient and sustainable
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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