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Topic Review
Spin
Spin is an intrinsic form of angular momentum carried by elementary particles, and thus by composite particles (hadrons) and atomic nuclei. Spin is one of two types of angular momentum in quantum mechanics, the other being orbital angular momentum. The orbital angular momentum operator is the quantum-mechanical counterpart to the classical angular momentum of orbital revolution and appears when there is periodic structure to its wavefunction as the angle varies. For photons, spin is the quantum-mechanical counterpart of the polarization of light; for electrons, the spin has no classical counterpart. The existence of electron spin angular momentum is inferred from experiments, such as the Stern–Gerlach experiment, in which silver atoms were observed to possess two possible discrete angular momenta despite having no orbital angular momentum. The existence of the electron spin can also be inferred theoretically from the spin–statistics theorem and from the Pauli exclusion principle—and vice versa, given the particular spin of the electron, one may derive the Pauli exclusion principle. Spin is described mathematically as a vector for some particles such as photons, and as spinors and bispinors for other particles such as electrons. Spinors and bispinors behave similarly to vectors: they have definite magnitudes and change under rotations; however, they use an unconventional "direction". All elementary particles of a given kind have the same magnitude of spin angular momentum, though its direction may change. These are indicated by assigning the particle a spin quantum number. The SI unit of spin is the same as classical angular momentum (i.e., N·m·s, J·s, or kg·m2·s−1). In practice, spin is given as a dimensionless spin quantum number by dividing the spin angular momentum by the reduced Planck constant ħ, which has the same dimensions as angular momentum, although this is not the full computation of this value. Very often, the "spin quantum number" is simply called "spin". The fact that it is a quantum number is implicit.
  • 4.0K
  • 27 Oct 2022
Topic Review
Stable Packaging and Producer Cell Lines for AAV
Today, recombinant adeno-associated virus (rAAV) vectors represent the vector systems which are mostly used for in vivo gene therapy for the treatment of rare and less-rare diseases. Although most of the past developments have been performed by using a transfection-based method and more than half of the authorized rAAV-based treatments are based on transfection process, the tendency is towards the use of stable inducible packaging and producer cell lines because their use is much more straightforward and leads in parallel to reduction in the overall manufacturing costs.
  • 4.0K
  • 29 Feb 2024
Topic Review
Civilian
Civilians under international humanitarian law are "persons who are not members of the armed forces" and are not "combatants if they [do not] carry arms openly and respect the laws and customs of war". It is slightly different from a non-combatant, as some non-combatants are not civilians (for example, military chaplains attached to the belligerent party or military personnel serving with a neutral country). Civilians in the territories of a party to an armed conflict are entitled to certain privileges under the customary laws of war and international treaties such as the Fourth Geneva Convention. The privileges that they enjoy under international law depends on whether the conflict is an internal one (a civil war) or an international one. In some nations, uniformed members of civilian police or fire departments colloquially refer to members of the public as civilians.
  • 4.0K
  • 29 Nov 2022
Topic Review
Mooncake
A mooncake (simplified Chinese: 月饼; traditional Chinese: 月餅; pinyin: yuè bǐng; Jyutping: jyut6 beng2; Yale: yuht béng) is a Chinese bakery product traditionally eaten during the Mid-Autumn Festival (中秋節). The festival is for lunar appreciation and moon watching, when mooncakes are regarded as an indispensable delicacy. Mooncakes are offered between friends or on family gatherings while celebrating the festival. The Mid-Autumn Festival is one of the four most important Chinese festivals. Typical mooncakes are round pastries, measuring about 10 cm in diameter and 3–4 cm thick, and are commonly eaten in the Southern Chinese regions of Guangdong, Guangxi, Hong Kong and Macau. A rich thick filling usually made from red bean or lotus seed paste is surrounded by a thin (2–3 mm) crust and may contain yolks from salted duck eggs. Mooncakes are usually eaten in small wedges accompanied by tea. Today, it is customary for businessmen and families to present them to their clients or relatives as presents, helping to fuel a demand for high-end mooncakes. Due to China's influence, mooncakes and Mid-Autumn Festival are also enjoyed and celebrated in other parts of Asia. Mooncakes have also appeared in western countries as a form of delicacy.
  • 4.0K
  • 22 Nov 2022
Topic Review
Enlightenment in Buddhism
The English term enlightenment is the western translation of the abstract noun bodhi, (/ˈboʊdi/; Sanskrit: बोधि; Pali: bodhi), the knowledge or wisdom, or awakened intellect, of a Buddha. The verbal root budh- means "to awaken," and its literal meaning is closer to "awakening." Although the term buddhi is also used in other Indian philosophies and traditions, its most common usage is in the context of Buddhism. The term "enlightenment" was popularised in the Western world through the 19th century translations of Max Müller. It has the western connotation of general insight into transcendental truth or reality. The term is also being used to translate several other Buddhist terms and concepts, which are used to denote (initial) insight (prajna (Sanskrit), wu (Chinese), kensho and satori(Japanese)); knowledge (vidhya); the "blowing out" (Nirvana) of disturbing emotions and desires and the subsequent freedom or release (vimukti); and the attainment of supreme Buddhahood (samyak sam bodhi), as exemplified by Gautama Buddha. What exactly constituted the Buddha's awakening is unknown. It may probably have involved the knowledge that liberation was attained by the combination of mindfulness and dhyāna, applied to the understanding of the arising and ceasing of craving. The relation between dhyana and insight is a core problem in the study of Buddhism, and is one of the fundamentals of Buddhist practice. In the western world the concept of (spiritual) enlightenment has taken on a romantic meaning. It has become synonymous with self-realization and the true self and false self, being regarded as a substantial essence being covered over by social conditioning., , ,
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  • 28 Oct 2022
Topic Review
Inflammatory Cytokines Induce Melanogenesis
The production of melanin pigments by melanocytes and their quantity, quality, and distribution play a decisive role in determining human skin, eye, and hair color, and protect the skin from adverse effects of ultraviolet radiation (UVR) and oxidative stress from various environmental pollutants. Melanocytes reside in the basal layer of the interfollicular epidermis and are compensated by melanocyte stem cells in the follicular bulge area. Various stimuli such as eczema, microbial infection, ultraviolet light exposure, mechanical injury, and aging provoke skin inflammation. These acute or chronic inflammatory responses cause inflammatory cytokine production from epidermal keratinocytes as well as dermal fibroblasts and other cells, which in turn stimulate melanocytes, often resulting in skin pigmentation. It is confirmed by some recent studies that several interleukins (ILs) and other inflammatory mediators modulate the proliferation and differentiation of human epidermal melanocytes and also promote or inhibit expression of melanogenesis-related gene expression directly or indirectly, thereby participating in regulation of skin pigmentation. Understanding of mechanisms of skin pigmentation due to inflammation helps to elucidate the relationship between inflammation and skin pigmentation regulation and can guide development of new therapeutic pathways for treating pigmented dermatosis. 
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  • 07 May 2021
Topic Review
Web Search Engine
A web search engine or Internet search engine is a software system that is designed to carry out web search (Internet search), which means to search the World Wide Web in a systematic way for particular information specified in a textual web search query. The search results are generally presented in a line of results, often referred to as search engine results pages (SERPs). The information may be a mix of links to web pages, images, videos, infographics, articles, research papers, and other types of files. Some search engines also mine data available in databases or open directories. Unlike web directories, which are maintained only by human editors, search engines also maintain real-time information by running an algorithm on a web crawler. Internet content that is not capable of being searched by a web search engine is generally described as the deep web.
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  • 19 Oct 2022
Topic Review
Capybara (Hydrochoerus hydrochaeris)
The capybara (Hydrochoerus hydrochaeris) is a large, semi-aquatic mammal native to South America, recognized for its sociable behavior, robust physical form, and distinctive appearance. As the largest living rodent species, the capybara typically inhabits wetlands, riverbanks, and grasslands throughout the continent, ranging from Colombia and Venezuela to Argentina and Uruguay. It plays a significant ecological role in its native habitat and is closely associated with freshwater environments due to its need for access to water for survival and feeding. The capybara has garnered attention in recent years due to its distinctive social structure and behaviors, as well as its relatively calm disposition when interacting with humans and other species.
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  • 08 Jul 2025
Topic Review
Mitogen-Activated Protein Kinases (MAPKs)
Kinases are considered the largest protein family in the human proteome, and approximately 2% of eukaryotic genes encode kinase superfamily members. These enzymes catalyze the transference of the γ-phosphate from ATP to serine, threonine, or tyrosine amino acid residues of a downstream protein substrate, creating a communication cascade that is fundamental to eukaryotic cells. 
  • 4.0K
  • 26 Apr 2021
Biography
Venkatraman Ramakrishnan
Venkatraman "Venki" Ramakrishnan (born 1952)[1] is an American and British structural biologist of Indian origin. He was elected President of the Royal Society in November 2015; Presidents serve for five years.[2] In 2009 he shared the Nobel Prize in Chemistry with Thomas A. Steitz and Ada Yonath, "for studies of the structure and function of the ribosome".[3][4][5][6][7] Since 1999, he has wor
  • 4.0K
  • 21 Nov 2022
Topic Review
Phlegm Syndrome
Phlegm is defined as a viscous and turbid pathological factor that is formed due to an imbalance in body fluid in traditional East Asian medicine (TEAM) and accumulates in certain parts of the body as the form of condensation.
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  • 12 Oct 2021
Topic Review
Voxelisation Algorithms
Voxel-based data structures, algorithms, frameworks, and interfaces have been used in computer graphics and many other applications for decades. There is a general necessity to seek adequate digital representations, such as voxels, that would secure unified data structures, multi-resolution options, robust validation procedures and flexible algorithms for different 3D tasks.
  • 4.0K
  • 19 Jan 2022
Topic Review
Techno-Economic and Life Cycle Cost Analysis
The techno-economic analysis (TEA) and the life cycle cost analysis (LCCA) are the most widely used approaches for modeling and calculating processes’ economic impacts. A simulation-based TEA is a cost-benefit analysis that simultaneously considers technical and economic factors. In addition, the method facilitates the development of the entire project and provides a systematic approach for examining the interrelationships between economic and technological aspects. When it comes to economic studies, it is intimately bonded with uncertainty. There are numerous uncertainty sources, classified in various ways. The uncertainty reflects “an inability to determine the precise value of one or more parameters affecting a system.” The variability refers to the different values a given parameter may take. This implies that a probability density function (PDF), for instance, can be employed to estimate and quantify the variability of a given parameter. The bias refers to “assumptions that skew an analysis in a certain direction while ignoring other legitimate alternatives, factors, or data.” 
  • 4.0K
  • 21 Oct 2022
Topic Review
Defect-Related Etch Pits on Crystals and Their Utilization
Etch pits could form on an exposed surface of a crystal when the crystal is exposed to an etching environment or chemicals. Due to different dissolution rates along various crystalline directions in a crystal, the dissolution process is anisotropic; hence, etch pits usually have a regular shape. The morphology, size, and density of etch pits can be affected by various factors, including the chemical composition of the etchant, etching time, etching temperature, status of the matrix, and so on. Traditionally, etch pits are utilized to evaluate the dislocation density and some defect-related properties. Now, in the modern fabrication industries, the relationship between etch pits and defects has been utilized more skillfully. High-quality crystals can be fabricated by controlling dislocations revealed by etch pits. Meanwhile, with the as-revealed dislocation as the diffusion path of atoms, new crystals will emerge in corresponding etch pits.
  • 4.0K
  • 11 Nov 2022
Topic Review
Cyc
Cyc (pronounced /ˈsaɪk/ SYKE) is a long-term artificial intelligence project that aims to assemble a comprehensive ontology and knowledge base that spans the basic concepts and rules about how the world works. Hoping to capture common sense knowledge, Cyc focuses on implicit knowledge that other AI platforms may take for granted. This is contrasted with facts one might find somewhere on the internet or retrieve via a search engine or Wikipedia. Cyc enables semantic reasoners to perform human-like reasoning and be less "brittle" when confronted with novel situations. Douglas Lenat began the project in July 1984 at MCC, where he was Principal Scientist 1984–1994, and then, since January 1995, has been under active development by the Cycorp company, where he is the CEO.
  • 4.0K
  • 19 Oct 2022
Topic Review
Pan-Islamism
Pan-Islamism (Arabic: الوحدة الإسلامية) is a political movement advocating the unity of Muslims under one Islamic country or state – often a caliphate – or an international organization with Islamic principles. Pan-Islamism was launched in Turkey at the end of the 19th century by Sultan Abdul-Hamid II for the purpose of combating the process of westernization and fostering the unification of Islam. Pan-Islamism differentiates itself from pan-nationalistic ideologies, for example Pan-Arabism, by seeing the ummah (Muslim community) as the focus of allegiance and mobilization, excluding ethnicity and race as primary unifying factors. The major leaders of the Pan-Islamist movement were the triad of Jamal al-Din Afghani (1839 - 1897), Muhammad Abduh (1849 - 1905) and Sayyid Rashid Rida (1865 - 1935); who were active in anti-colonial efforts to confront European penetration of Muslim lands. They also sought to strengthen Islamic unity, which they believed to be the strongest force to mobilize Muslims against imperial domination. Following Ibn Saud's conquest of Arabian Peninsula; pan-Islamism would be bolstered across the Islamic World. During the second half of the twentieth century; pan-Islamists would compete against secular nationalist ideologies in the Arab World such as Nasserism.
  • 4.0K
  • 15 Nov 2022
Topic Review
Intra-Articular Administration of Therapeutics for Joint Disorders
Several acute and chronic inflammatory diseases of the joints affect individuals. Intra-articular (IA) drug delivery is often preferred when the joint disease is severe and painful since it places high concentrations of the drug directly at the desired site. Researchers have reported different strategies for increasing the local retention of the intra-articularly administered medication. 
  • 4.0K
  • 23 Nov 2022
Topic Review
Calcareous Tufa
The term calcareous tufa, or freshwater travertine, is widely used in the scientific literature to describe carbonate deposits precipitated from cool groundwaters of meteoric origin enriched in CO2 (carbon dioxide) by percolating through organic soils.
  • 4.0K
  • 11 May 2023
Topic Review
Chinese Information Operations and Information Warfare
Informatized warfare of China is the implementation of information warfare (IW) within the Chinese military. Laid out in the Chinese Defence White Paper of 2008, informatized warfare includes the utilization of information-based weapons and forces, including battlefield management systems, precision-strike capabilities, and technology-assisted command and control (C4ISR). However, some media and analyst report also uses the term to describe the political and espionage effort from the Chinese state.
  • 4.0K
  • 14 Oct 2022
Topic Review
GeForce 8 Series
The GeForce 8 series is the eighth generation of Nvidia's GeForce line of graphics processing units. The third major GPU architecture developed by Nvidia, Tesla represents the company's first unified shader architecture.
  • 4.0K
  • 26 Oct 2022
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