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Topic Review
Shambhala
In Tibetan Buddhist tradition, Shambhala (Sanskrit: शम्भल Śambhala, also spelled Shambala or Shamballa; Tibetan: བདེ་འབྱུང, Wylie: Bde'byung; Chinese: 香巴拉; pinyin: Xiāngbālā) is a mythical kingdom. Shambhala is mentioned in the Kalacakra Tantra. The Bon scriptures speak of a closely related land called Tagzig Olmo Lung Ring. The Sanskrit name is taken from the name of a city mentioned in the Hindu Puranas, probably in reference to Sambhal in Uttar Pradesh. The mythological relevance of the place originates with a prophecy in Vishnu Purana (4.24) according to which Shambhala will be the birthplace of Kalki, the final incarnation of Vishnu, who will usher in a new Age (Satya Yuga).
  • 5.7K
  • 01 Dec 2022
Topic Review
Folic Acid, Vitamin B12 and Chronic Kidney Disease
Patients affected by chronic kidney disease (CKD) or end-stage renal disease (ESRD) experience a huge cardiovascular risk and cardiovascular events represent the leading causes of death. Folic acid and vitamin B12 could not only be mere cofactors in the homocysteine metabolism; they may have a direct action in determining tissue damage and cardiovascular risk. 
  • 5.7K
  • 15 Oct 2021
Topic Review
Composite Material Applications
Composite materials are composed of two or more different materials having considerably different physical and/or chemical characteristics that, when merged, produce a material with attributes that differ from the separate elements. Composite materials are extensively utilized in the automobile, construction, transportation, aerospace, and renewable energy applications due to their durability, high strength, great quality, minimal maintenance, and low weight.
  • 5.7K
  • 08 Oct 2021
Topic Review
Catalyst Design via Colloidal Synthesis
Supported nanoparticles are commonly applied in heterogeneous catalysis. The catalytic performance of these solid catalysts is, for a given support, dependent on the nanoparticle size, shape, and composition, thus necessitating synthesis techniques that allow for preparing these materials with fine control over those properties. Such control can be exploited to deconvolute their effects on the catalyst’s performance, which is the basis for knowledge-driven catalyst design. In this regard, bottom-up synthesis procedures based on colloidal chemistry have proven successful in achieving the desired level of control for a variety of fundamental studies. This article aims to give an overview of recent progress made in this synthesis technique for the application of controlled catalytic materials in gas-phase catalysis. The focus goes to mono- and bimetallic materials, as well as to recent efforts in enhancing their performance by embedding colloidal templates in porous oxide phases.
  • 5.7K
  • 12 May 2021
Topic Review
Sarcopterygii
Sarcopterygii (/ˌsɑːrkɒptəˈrɪdʒi.aɪ/; from grc σάρξ (sárx) 'flesh', and πτέρυξ (ptérux) 'wing, fins')—sometimes considered synonymous with Crossopterygii (from grc κροσσός (krossós) 'fringe')—is a taxon (traditionally a class or subclass) of the bony fishes whose members are known as lobe-finned fishes. The group Tetrapoda, a superclass including amphibians, reptiles (including dinosaurs and therefore birds), and mammals, evolved from certain sarcopterygians; under a cladistic view, tetrapods are themselves considered a group within Sarcopterygii. The known extant non-tetrapod sarcopterygians include two species of coelacanths and six species of lungfishes.
  • 5.7K
  • 27 Oct 2022
Topic Review
Beta-Carotene
β-Carotene is an organic, strongly coloured red-orange pigment abundant in fungi, plants, and fruits. It is a member of the carotenes, which are terpenoids (isoprenoids), synthesized biochemically from eight isoprene units and thus having 40 carbons. Among the carotenes, β-carotene is distinguished by having beta-rings at both ends of the molecule. β-Carotene is biosynthesized from geranylgeranyl pyrophosphate. In some Mucoralean fungi, β-Carotene is a precursor to the synthesis of trisporic acid. β-Carotene is the most common form of carotene in plants. When used as a food coloring, it has the E number E160a.:119 The structure was deduced by Karrer et al. in 1930. In nature, β-carotene is a precursor (inactive form) to vitamin A via the action of beta-carotene 15,15'-monooxygenase. Isolation of β-carotene from fruits abundant in carotenoids is commonly done using column chromatography. It can also be extracted from the beta-carotene rich algae, Dunaliella salina. The separation of β-carotene from the mixture of other carotenoids is based on the polarity of a compound. β-Carotene is a non-polar compound, so it is separated with a non-polar solvent such as hexane. Being highly conjugated, it is deeply colored, and as a hydrocarbon lacking functional groups, it is very lipophilic.
  • 5.7K
  • 16 Nov 2022
Topic Review
Entrepreneurship in the Sustainable Development Goals
Entrepreneurship plays a prominent and noteworthy role in promoting the Sustainable Development Goals (SDGs). Entrepreneurship, through the creation of new businesses, is recognized as a vital driver in providing employment, reducing inequalities, alleviating poverty, and fostering sustainable growth.
  • 5.7K
  • 18 Feb 2024
Topic Review
Sugar Based Surfactants
Sugar-based surfactants are a class of surfactants derived from natural sugars, such as glucose, sucrose, and maltose. These surfactants have gained significant interest in recent years due to their biodegradability, low toxicity, and high compatibility with biological systems. Sugar-based surfactants are classified into two main groups: alkyl polyglucosides (APGs) and saccharide fatty acid esters (SFAEs). APGs are produced by reacting a fatty alcohol with glucose, while SFAEs are produced by esterifying a sugar molecule with a fatty acid. APGs have excellent cleaning and foaming properties and are used in a variety of personal care and household products, including shampoos, body washes, and dishwashing detergents. SFAEs are mainly used in the food industry as emulsifiers and stabilizers. One of the main advantages of sugar-based surfactants is their biodegradability, which means that they break down into harmless substances when exposed to environmental conditions such as sunlight, water, and microorganisms. This makes them an attractive alternative to synthetic surfactants, which can persist in the environment for a long time and have negative impacts on ecosystems.
  • 5.7K
  • 24 Mar 2023
Topic Review
Gallium Nitride High-Electron-Mobility Transistor
In recent years, GaN-based devices have been widely used in a variety of application fields. GaN-based high-electron-mobility transistors (HEMTs) are superior to conventional silicon (Si) based devices in terms of switching frequency, power rating, thermal capability and efficiency, which are crucial factors to enhance the performances of advanced power converters. This paper addresses some fundamental issues concerning intrinsic features of GaN material and key technology in practical application of GaN-based power switching devices.
  • 5.7K
  • 30 Jul 2020
Topic Review
Abiotic and Biotic Polymer Degradation Mechanisms
Polymer degradation is defined as an irreversible change of the chemical structure, physical properties, and visual appearance due to the chemical cleavage of the polymer’s constitutive macromolecules by one or more mechanism. More than one mechanism can simultaneously take place due to the action of external factors, and one mechanism can be more dominant than others at any time. External factors associated with the environment, such as heat, humidity, radiation, and acidic or alkaline conditions, could modify the degradation process and its rate. The degradation process can alter polymer properties such as mechanical, optical, electrical, discoloration, phase separation or delamination, erosion, cracking, and crazing. The four main abiotic mechanisms associated with polymer degradation are mechanical, thermal (or thermo-oxidative), photo (photo-oxidative), and hydrolytic (chemical) degradation, some of which can be assisted by catalysis. In addition, ozone degradation (chemical) is considered a mechanism of degradation for polymers but is less common. The biotic degradation involves the action of microorganisms by enzymatic action.
  • 5.7K
  • 27 Oct 2022
Topic Review
Biological Properties of Flavonoids
It has been reported that nutritional phytochemicals present in fruits, vegetables and cereals, such as flavonoid polyphenolic compounds, can improve bone mineral density by several mechanisms, in addition to having beneficial effects on bone homeostasis and health. In addition to their nutritional properties, flavonoids may have applicability in the manufacture of polymers and can be used as stabilizing agents for biopolyesters, such as polylactide (PLA) and polyhydroxyalkanoate (PHA), which have been widely used in tissue engineering for membranes and scaffolds.
  • 5.7K
  • 11 May 2022
Topic Review
CubeSat Missions and Their Antenna Designs
CubeSats are a class of miniaturized satellites that have become increasingly popular in academia and among hobbyists due to their short development time and low fabrication cost. Their compact size, lightweight characteristics, and ability to form a swarm enables them to communicate directly with one another to inspire new ideas on space exploration, space-based measurements, and implementation of the latest technology. CubeSat missions require specific antenna designs in order to achieve optimal performance and ensure mission success. Over the past, a plethora of antenna designs have been proposed and implemented on CubeSat missions. Several challenges arise when designing CubeSat antennas such as gain, polarization, frequency selection, pointing accuracy, coverage, and deployment mechanisms.
  • 5.7K
  • 18 Jul 2022
Topic Review
Wave Energy Marine Buoys
The power supply is usually the bottleneck for marine distributed systems such as buoys. Wave energy technologies are especially useful in this sense, as they can capture and convert the promising “native” renewable energy in the ocean (i.e., wave energy) into electricity.
  • 5.7K
  • 08 Jul 2022
Topic Review
Intrinsic Self-Healing Polymers
Self-healing polymeric materials have been widely investigated because they can heal the damages spontaneously and thereby prolong their service lifetime. Many ingenious synthetic procedures have been developed for fabricating self-healing polymers with high performance.
  • 5.7K
  • 20 Sep 2022
Topic Review
Phosphate in Primary Hyperparathyroidism
Serum phosphate is crucial in the management of kidney disease, playing a major role in vascular calcification in chronic kidney failure.  In the past 20 years, the role of phosphate has been profoundly reconsidered since many other molecules have been found to play important roles in phosphate homeostasis, beyond the well-known effect of parathyroid hormone (PTH) or renal function. The advent of new insights into phosphate metabolism must urge the endocrinologist to rethink the pathophysiology of widespread disorders, such as primary hyperparathyroidism.
  • 5.7K
  • 15 Dec 2021
Topic Review
Half-Reaction
A half reaction (or half-cell reaction) is either the oxidation or reduction reaction component of a redox reaction. A half reaction is obtained by considering the change in oxidation states of individual substances involved in the redox reaction. Often, the concept of half reactions is used to describe what occurs in an electrochemical cell, such as a Galvanic cell battery. Half reactions can be written to describe both the metal undergoing oxidation (known as the anode) and the metal undergoing reduction (known as the cathode). Half reactions are often used as a method of balancing redox reactions. For oxidation-reduction reactions in acidic conditions, after balancing the atoms and oxidation numbers, one will need to add H+ ions to balance the hydrogen ions in the half reaction. For oxidation-reduction reactions in basic conditions, after balancing the atoms and oxidation numbers, first treat it as an acidic solution and then add OH− ions to balance the H+ ions in the half reactions (which would give H2O).
  • 5.7K
  • 28 Nov 2022
Topic Review
Kuroshio Current
The Kuroshio (黒潮), also known as the Black or Japan Current (日本海流, Nihon Kairyū) or the Black Stream, is a north-flowing, warm ocean current on the west side of the North Pacific Ocean. Like the Gulf Stream in the North Atlantic, the Kuroshio is a powerful western boundary current and forms the western limb of the North Pacific Subtropical Gyre.
  • 5.7K
  • 09 Oct 2022
Topic Review
Leucine Metabolism
Leucine, an essential branched amino acid, has anti-obesity effects on glucose tolerance, lipid metabolism, and insulin sensitivity. The catabolism of Leucine is a conserved regulator of physiological aging, participating in diverse physiological and pathological processes. This topic review offers an up-to-date report on the decomposition and metabolites of leucine in mammals, as α-ketoisocaproate (KIC) and β-hydroxy-β-methylbutyrate (HMB).
  • 5.7K
  • 29 Oct 2020
Topic Review
Ras Al Khaimah
Ras Al Khaimah (Arabic: رأس الخيمة; IPA: [raʔs alˈxajma]), historically known as Julfar, is one of the seven emirates that make up the United Arab Emirates (UAE). The capital city and home of most residents is also called Ras Al Khaimah, sometimes abbreviated as RAK city. Its name could be taken to mean "headland of the small huts", which can be attributed to the indigenous buildings that existed along the coast. The emirate is in the northern part of the UAE, bordering Oman's exclave of Musandam. It covers an area of 2,486 km2 (960 sq mi). The emirate had a population of 210,063 at the 2005 Census, of which 41.82 percent or 87,848 were Emirati citizens. Latest estimates put the total population at between 250,000 and 300,000. Locals accounted for 97,529 in the population estimate for 2010. Its capital city RAK city has two main sections, Old Ras Al Khaimah and Nakheel, on either side of a creek. It is served by the Ras Al Khaimah International Airport. It consists of a northern part (where the city of Ras al-Khaimah is situated), and a large inland exclave in the south (near Hatta), and a few small islands in the Persian Gulf. Ras Al Khaimah has the most fertile soil in the country, due to a larger share in rainfall and underground water streams from Omani mountains.
  • 5.7K
  • 19 Oct 2022
Topic Review
Biostimulants
Biostimulants represent a promising type of environment-friendly formulation based on natural products that are frequently used exogenously to enhance abiotic stress tolerance. There is no specific definition of biostimulants yet, despite their regulatory functions in plant growth and development. Biostimulants originate from natural sources and can be effectively categorized into the following four prime groups, namely, acids, microbes, plant-derived bioactive substances, and others.
  • 5.7K
  • 08 Apr 2022
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