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Topic Review

Applications of Carbon Dots

Although there is significant progress in the research of carbon dots (CDs), some challenges such as difficulty in large-scale synthesis, complicated purification, low quantum yield, ambiguity in structure-property correlation, electronic structures, and photophysics are still major obstacles that hinder the commercial use of CDs. The unique properties of CDs, such as good biocompatibility, high photostability, excellent light-harvesting, up-conversion, effective electron transfer, and bandgap narrowing, make the CDs promising nanomaterials for applications in many fields.

2.7K
25 Aug 2022

Topic Review

IBM Basic Assembly Language and Successors

Basic Assembly Language (BAL) is the commonly used term for a low-level programming language used on IBM System/360 and successor mainframes. Originally "Basic Assembly Language" applied only to an extremely restricted dialect designed to run under control of IBM Basic Programming Support (BPS/360) on systems with only 8 KB of main memory, and only a card reader, a card punch, and a printer for input/output — thus the word "Basic". However, the full name and the initialism "BAL" almost immediately attached themselves in popular use to all assembly-language dialects on the System/360 and its descendants. BAL for BPS/360 was introduced with the System/360 in 1964. Assemblers on other System/360 operating systems through System/370, System/390, and System z, as well as the UNIVAC Series 90 mainframes made by Sperry Corporation, and the BS2000 Mainframes currently made by Fujitsu, inherited and extended its syntax. The latest derived language is known as the IBM High-Level Assembler (HLASM). Programmers utilizing this family of assemblers also refer to them as ALC, (for Assembly Language Coding), or simply "assembler". BAL is also the mnemonic of the "Branch And Link" instruction.

2.7K
19 Oct 2022

Topic Review

Acridine, an alkaloid from anthracene, also known by the names of 10-azaanthracene, dibenzopyridine, 2,3,5,6-dibenzopyridine, and its derivatives or analogs, have a great potential to be an efficient class of excellent inhibitor. The phenomenon of corrosion threatens metallic components, human safety, and the economy. Despite being eco-friendly and promising as a corrosion inhibitor, acridine has not been explored to its full potential.

2.7K
09 Nov 2022

Topic Review

University of Florida Taser Incident

The University of Florida Taser incident was an incident in which a University of Florida student was stunned with a taser at a forum featuring then U.S. Senator John Kerry. On September 17, 2007, Kerry addressed a Constitution Day forum at the University of Florida campus in Gainesville, which was organized by the ACCENT Speakers Bureau, an agency of the university's student government. Andrew Meyer, a 21-year-old fourth-year undergraduate mass communication student, had initially been allowed to ask a question after the close of the question period. He asked Kerry whether he was a member of Skull and Bones, as George W. Bush is, implying that Kerry did not contest Bush's presidency because of their shared affiliation. Meyer was forcibly pulled away from the microphone. He was immediately restrained and forcibly removed and was subsequently arrested by university police. During his arrest, Meyer struggled and screamed for help. While six officers held Meyer down, one of the officers drive-stunned him with a taser following Meyer's shouted plea to the police, "Don't tase me, bro!" Several videos of the episode were posted on the Web, with one version reaching 7 million views on YouTube. The New Oxford American Dictionary listed tase or taze as one of the words of the year for 2007, popularized by the widespread use of the phrase. Meyer registered the phrase as a trademark in September 2007.

2.7K
23 Nov 2022

Topic Review

Antimicrobial-resistance genes in human gut

Antibiotic-resistance has long been associated with the use and abuse of antibiotics. However, increasing evidence is suggesting that antibiotic-resistance is in fact a phenomenon that has been occurring in natural environments for thousands and possibly millions of years. With the expansion of the microbiome field, it is now possible to characterize antibiotic-resistance genes altogether in different samples, including the human gut. This has also enabled the characterization of ancient human gut microbiomes, which also include antibiotic-resistance genes. Mummified gut remains represent a unique opportunity to characterize the microbiome and antibiotic-resistance genes prior the antibiotic-therapy era. Surprisingly, mummies from the Inca and Italian nobility cultures showed to possess antibiotic-resistance-like genes similar to modern-day antibiotic-resistance genes conferring resistance to beta-lactams, sulfa, quinolones and vancomycin, just to mention a few examples. This is intriguing as it further supports that antibiotic-resistance began in the environment and was transferred to the human gut by means that remain to be investigated and are a matter of ongoing speculation.

2.7K
29 Oct 2020

Topic Review

Reproductive Technologies Used in Male Neo-Tropical Hystricomorphic Rodents

To improve efficient reproduction, reproductive technologies are commonly used in domesticated animals; therefore, it is wise to explore the feasibility of their application on Neo-tropical rodents, an alternative meat source with the potential to aid in conservation and wildlife farming. However, there must first be a proper understanding of their reproductive anatomy, before reproductive technologies can be utilized. The penis of the agouti and the paca (Cuniculus paca), for example, were found to be covered in penile spines with two keratinized spines and two lateral penile cartilages on either side of the glans penis, unlike the capybara (Hydrochoerus hydrochaeris). Different methods can be used to collect semen from these animals and, based on the performed review, it has been shown that coconut water powder (ACP-123) is a good diluent for both the agouti and the paca, giving higher spermatozoa parameters compared with those obtained via electro ejaculation.

2.7K
17 Jan 2022

Topic Review

Preparation Methods for Large-Area Perovskite Solar Cells

Solar energy is one of the most encouraging, abundant, green, and renewable sources for decreasing or even replacing traditional energy in the future. The energy provided by the sun in one hour is sufficient to supply the Earth’s needs for an entire year. The recent rapid development in perovskite solar cells (PSCs) has led to significant research interest due to their notable photovoltaic performance, currently exceeding 25% power conversion efficiency for small-area PSCs. The materials used to fabricate PSCs dominate the current photovoltaic market, especially with the rapid increase in efficiency and performance.

2.7K
12 Apr 2022

Topic Review

Synthesis of 2,5-Furandicarboxylic Acid

The most versatile furanic building block for chemical and polymer applications is 2,5-furandicarboxylic acid. However, the classical 2,5-furandicarboxylic acid production methodology has been found to have significant drawbacks that hinder industrial-scale production. The following content highlights new alternative methods to synthesize 2,5-furandicarboxylic acid that are both more advantageous and attractive than conventional oxidation of 5-hydroxymethylfurfural.

2.7K
19 Jul 2022

Topic Review

Durga Puja, one of the most celebrated and grand festivals of India, particularly in West Bengal, has a deep historical, cultural, and spiritual significance. Originating as a form of Shakti worship in the Indian subcontinent, Durga Puja has evolved over millennia. This festival honors Goddess Durga, the embodiment of feminine power, who symbolizes the victory of good over evil. However, the practice and celebration of Durga Puja have faced numerous challenges over the centuries, especially during periods of foreign invasions and the rise of Islam and Christianity in India. Despite these obstacles, Durga Puja not only survived but flourished by adapting to the social, political, and religious changes of the time. This article traces the history of Durga Puja from its ancient roots, examines how it weathered foreign invasions, and explores how it continues to thrive in the modern world.

2.7K
31 Oct 2024

Topic Review

IgG antibodies include two functional portions: the F(ab′)2 fragment, which is responsible for antigen recognition, and the crystallizable fragment (Fc), which is important for activation of the immune response by interacting with Fcγ receptors on B-cells and other innate immune cells. The Fc fragment also plays an important role in the activation of complement and in the clearance of microorganisms.

2.7K
01 Nov 2020

Topic Review

Chromogenic Technologies for Energy Saving

Chromogenic materials and devices include a wide range of technologies that are capable of changing their spectral properties according to specific external stimuli. Several studies have shown that chromogenics can be conveniently used in building façades in order to reduce energy consumption, with other significant effects. First of all, chromogenics influence the annual energy balance of a building, achieving significant reductions in consumption for HVAC and artificial lighting. In addition, these technologies potentially improve the indoor level of visual comfort, reducing the risks of glare and excessive lighting.

2.7K
19 Dec 2020

Topic Review

Rotational Piezoelectric Energy Harvesting

Rotational Piezoelectric Energy Harvesting (RPZTEH) is widely used due to mechanical rotational input power availability in industrial and natural environments. This paper reviews the recent studies and research in RPZTEH based on its excitation elements and design and their influence on performance. It presents different groups for comparison according to their mechanical inputs and applications, such as fluid (air or water) movement, human motion, rotational vehicle tires, and other rotational operational principal including gears. The work emphasises the discussion of different types of excitations elements, such as mass weight, magnetic force, gravity force, centrifugal force, gears teeth, and impact force, to show their effect on enhancing output power. It revealed that a small compact design with the use of magnetic, gravity, and centrifugal forces as excitation elements and a fixed piezoelectric to avoid a slip ring had a good influence on output power optimisation. One of the interesting designs that future works should focus on is using gear for frequency up-conversion to enhance output power density and keep the design simple and compact.

2.7K
12 Aug 2021

Topic Review

Born–Oppenheimer Approximation

In quantum chemistry and molecular physics, the Born–Oppenheimer (BO) approximation is the best-known mathematical approximation in molecular dynamics. Specifically, it is the assumption that the wave functions of atomic nuclei and electrons in a molecule can be treated separately, based on the fact that the nuclei are much heavier than the electrons. Due to the larger relative mass of a nucleus compared to an electron, the coordinates of the nuclei in a system are approximated as fixed, while the coordinates of the electrons are dynamic. The approach is named after Max Born and J. Robert Oppenheimer who proposed it in 1927, in the early period of quantum mechanics. The approximation is widely used in quantum chemistry to speed up the computation of molecular wavefunctions and other properties for large molecules. There are cases where the assumption of separable motion no longer holds, which make the approximation lose validity (it is said to "break down"), but even then the approximation is usually used as a starting point for more refined methods. In molecular infrared spectroscopy, using the BO approximation means considering molecular energy as a sum of independent terms, e.g.: [math]\displaystyle{ E_\text{total} = E_\text{electronic} + E_\text{vibrational} + E_\text{rotational} + E_\text{nuclear spin}. }[/math] These terms are of different orders of magnitude and the nuclear spin energy is so small that it is often omitted. The electronic energies [math]\displaystyle{ E_\text{electronic} }[/math] consist of kinetic energies, interelectronic repulsions, internuclear repulsions, and electron–nuclear attractions, which are the terms typically included when computing the electronic structure of molecules.

2.7K
16 Nov 2022

Biography

Chuck Hull (Charles W. Hull; born May 12, 1939) is the co-founder, executive vice president and chief technology officer of 3D Systems.[1][2] He is the inventor of the solid imaging process known as stereolithography (3D Printing), the first commercial rapid prototyping technology, and the STL file format. He is named on more than 60 U.S. patents as well as other patents around the world in the

2.7K
27 Dec 2022

Topic Review

Isotopes of Unbiunium

Check temperatures Ubu: no input for C, K, F. Check temperatures Ubu: no input for C, K, F. Unbiunium, also known as eka-actinium or simply element 121, is the hypothetical chemical element with symbol Ubu and atomic number 121. Unbiunium and Ubu are the temporary systematic IUPAC name and symbol respectively, until a permanent name is decided upon. In the periodic table of the elements, it is expected to be the first of the superactinides, and the third element in the eighth period: analogously to lanthanum and actinium, it could be considered the fifth member of group 3 and the first member of the fifth-row transition metals. It has attracted attention because of some predictions that it may be in the island of stability, although newer calculations expect the island to actually occur at a slightly lower atomic number, closer to copernicium and flerovium. Unbiunium has not yet been synthesized. Nevertheless, because it is only three elements away from the heaviest known element, oganesson (element 118), its synthesis may come in the near future; it is expected to be one of the last few reachable elements with current technology, and the limit may be anywhere between element 120 and 124. It will also likely be far more difficult to synthesize than the elements known so far up to 118, and still more difficult than elements 119 and 120. The team at RIKEN in Japan has plans to attempt the synthesis of element 121 in the future after its attempts on elements 119 and 120. The position of unbiunium in the periodic table suggests that it would have similar properties to its lighter congeners, scandium, yttrium, lanthanum, and actinium; however, relativistic effects may cause some of its properties to differ from those expected from a straight application of periodic trends. For example, unbiunium is expected to have a s2p valence electron configuration instead of the s2d of its lighter congeners in group 3, but this is not expected to significantly affect its chemistry, which is predicted to be that of a normal group 3 element; it would on the other hand significantly lower its first ionisation energy beyond what would be expected from periodic trends.

2.7K
26 Oct 2022

Topic Review

Strategies for Improving Cell-Penetrating Peptides Stability and Delivery

Peptides play an important role in many fields, including immunology, medical diagnostics, and drug discovery, due to their high specificity and positive safety profile. However, for their delivery as active pharmaceutical ingredients, delivery vectors, or diagnostic imaging molecules, they suffer from two serious shortcomings: their poor metabolic stability and short half-life. Major research efforts are being invested to tackle those drawbacks, where structural modifications and novel delivery tactics have been developed to boost their ability to reach their targets as fully functional species.

2.7K
04 Nov 2022

Topic Review Peer Reviewed

Analyzing Cultural Routes and Their Role in Advancing Cultural Heritage Management within Tourism: A Systematic Review with a Focus on the Integration of Digital Technologies

This review constitutes a comprehensive systematic review analyzing cultural routes, with a particular focus on the concept of the cultural route as a tourist–cultural product. Within this framework, the paper offers an overview of contemporary technological challenges, concerns, and limitations. It thoroughly explores cutting-edge technologies pertaining to the promotion of cultural heritage, both in general and in the specific context of realizing the concept of the cultural route, a tourist–cultural service enriched by the utilization of new media. Additionally, it extensively references the latest techniques and models for enhancing the user experience of digital cultural tourism products. Moreover, the paper showcases existing digital platforms and tools that encapsulate and emphasize the notion of cultural tourism. It assesses the respective methodologies, technologies, and techniques employed in each case, accompanied by illustrative instances of their applications. Finally, an empirical evaluation was conducted focusing on user needs and expectations during a cultural route.

2.7K
29 Dec 2023

Topic Review

Calcium Transport Systems in Mitochondria

Calcium (Ca2+) is a divalent cation and a universal second messenger that regulates the most important functions and facets of all eukaryotic cells, including: gene expression, proliferation, regulation of bioenergetics, contraction of muscles, mediation of fertilization, and many other cellular functions. Regulation of free intracellular concentration of Ca2+ is an important mechanism for intracellular signaling, and it is a key component in the mediation of many cell functions and biochemical reactions, being crucial for signal transduction in cells. On top of all that, intra-mitochondrial Ca2+ regulates a cascade of physiological and pathophysiological processes in cells The normal level of intra-mitochondrial Са2+ is essential for the correct functioning of mitochondria; whereas Ca2+ overload is typical for a wide range of mitochondrial dysfunctions and pathophysiological processes. Homeostasis of Ca2+ in the mitochondria is determined by the delicate balance of mitochondrial Ca2+ transport systems in both the inner (IMM) and outer mitochondrial membrane (OMM). Ca2+ influx and efflux systems are composed of different components, including: channels, pumps, antiporters, or Ca2+ binding proteins that cooperate to maintain intra-mitochondrial Ca2+ homeostasis.

2.7K
18 Nov 2020

Topic Review

Therapeutic Approach of Flavonoid

Flavonoids are one of the most diverse families of bioactive phytochemicals, with over 9000 different compounds. According to IUPAC Recommendations (2017), the term “flavonoid” refers to compounds that have the basic structure of phenyl-substituted propylbenzene derivatives with C15 skeleton, C16 skeleton, and flavonolignans with C6–C3 lignan precursors. Flavonoids are divided into six subclasses; isoflavones, flavones, flavanols, flavonols, flavanones, and anthocyanins, are abundant in plants and their metabolic routes have been thoroughly explored using biochemical and molecular approaches.

2.7K
10 Nov 2021

Topic Review

LABs and Silage Production

Lactic acid bacteria (LAB) are considered potent natural additives for animal feed production due to the efficient production of biological metabolites—notably, higher lactic acid content with marginal level acetic acid and other organic acids. Furthermore, LAB can utilize water-soluble carbohydrates and convert them into valuable organic acids, which increase the acidification of the surrounding environment. Rapid acidification (lower pH) could help to prevent undesirable microbial growth and toxic secondary metabolite secretion.

2.7K
07 Jan 2022

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