1,721,542 research outputs found
Belt and Road Initiative may create new supplies for illegal wildlife trade in large carnivores
Full text linkHinsley, Amy/0000-0002-5590-7617; Farhadinia, Mohammad/0000-0002-5385-6254; Ambarli, Huseyin/0000-0003-4336-9417; Nawaz, Muhammad Ali/0000-0001-5632-9014WOS: 000484026600002PubMed: 31406278…Oxford Martin School at the University of Oxford; Oxford Martin Programme on the Illegal Wildlife TradeM.S.F. was supported by a research fellowship from the Oxford Martin School at the University of Oxford. A.H. was supported by the Oxford Martin Programme on the Illegal Wildlife Trade
Chances and limitations when uncovering essential and non‐essential genes of Bacillus subtilis phages with CRISPR‐Cas9
No full textProgress and Future Challenges in Designing High-Performance Ni/CeO2 Catalysts for CO2 Methanation: A Critical Review
No full textThe Ni/CeO2 catalyst stands out among various solid metal oxide catalysts for its exceptional catalytic proficiency, positioning it as a prime candidate for the industrialization of methanation processes. This review thoroughly examines the prevalent challenges associated with Ni/CeO2 in methanation reactions, compiles current strategies to overcome these hurdles, and presents novel perspectives. The review elucidates the structural characteristics of Ni/CeO2 and its applications in catalytic reactions, discusses various synthesis methods and their respective merits and demerits, explores catalytic reaction systems at both laboratory and industrial scales, and clarifies the underlying reaction mechanisms. Furthermore, it underscores the mainstream approaches to enhance the low-temperature activity of Ni/CeO2 in methanation and to mitigate activity decrement due to Ni agglomeration. The review concludes by proposing future directions for improving low-temperature methanation activity and preventing catalyst deactivation, encompassing the development of innovative catalyst architectures, integrating in-situ characterization with theoretical calculations, and investigating photothermal methanation catalytic systems. Undoubtedly, scientific researchers will persistently strive to develop Ni/CeO2 catalysts with high activity across a broad temperature range and robust stability, driving the industrialization of CO2 methanation technology in the foreseeable future.The authors are grateful for financial support from the National Natural Science Foundation of China (grant no. 52203110) and the Natural Science Foundation of Fujian (grant no. 2024J01403).Peer reviewe
Decoding fundamental insights and outlooks on state-of-the-art iron-catalyst design strategies for meliorated CO2 valorization into light olefins
No full textThe valorization of carbon dioxide into high-value-added hydrocarbons, especially light olefins (C2-C4=) through sustainable energy input holds significant industrial value, offering a route for producing essential chemical feedstocks while simultaneously mitigating the emission of this potent greenhouse gas. Despite significant advancements in CO2 hydrogenation technologies, developing efficient catalysts capable of effectively managing C[sbnd]O bond activation and facilitating C[sbnd]C bond growth with high conversion rates and desired selectivity for low-carbon olefins, remains a significant challenge. This high-caliber review explores the transformative potential of CO2 valorization into C2-C4=, offering an innovative pathway to produce vital chemical feedstocks while addressing greenhouse gas emissions. Focusing on the CO2-modified Fischer-Tropsch synthesis through iron-catalyst, recognized for its energy efficiency and suitability for C2-C4= production through thermocatalytic CO2 hydrogenation. Key highlights include in-depth analyses of the dynamic nature of catalytically active iron phases, novel materials, and state-of-the-art catalyst design strategies to overcome the challenges of Anderson-Schulz-Flory (ASF) limitations and low olefin selectivity. With a comprehensive discussion on reaction mechanisms, catalyst composition, and performance-driving factors, this review sets the stage for pioneering advancements in catalyst development. Thus, by bridging fundamental insights with cutting-edge technologies, this work provides strategic guidance for developing the next generation of efficient and sustainable catalytic systems for CO2 hydrogenation.The authors are grateful for financial support from the Natural Science Foundation of Fujian Province (grant no. 2024J01403).Peer reviewe
Continuous degradation of maltose: Improvement in stability and catalytic properties of maltase (α-glucosidase) through immobilization using agar-agar gel as a support
No full textMaltose degrading enzyme was immobilized
within agar-agar support via entrapment method due to its
industrial utilization. The maximum immobilization efficiency
(82.77 %) was achieved using 4.0 % agar-agar
keeping the diameter of bead up to 3.0 mm. The matrix
entrapment showed maximum catalytic activity at pH 7.0
and temperature 65 C. Substrate saturation kinetics
showed that the Km of immobilized enzyme increased from
1.717 to 2.117 mM ml-1 where as Vmax decreased from
8,411 to 7,450 U ml-1 min-1 as compared to free enzyme.
The immobilization significantly increased the stability of
maltase against various temperatures and immobilized
maltase retain 100 % of its original activity after 2 h at
50 C, whereas the free maltase only showed 60 % residual
activity under same condition. The reusability of entrapped
maltase showed activity up to 12 cycles and retained 50 %
of activity even after 5th cycle. Storage stability of agar
entrapped maltase retain 73 % of its initial activity even
after 2 months when stored at 30 C while free enzyme
showed only 37 % activity at same storage conditions
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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