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Topic Review
Regulation of Central and Peripheral Blood Pressure
Pressure in the primary arteries near the heart and the brain is known as central blood pressure (CBP), while that in the peripheral arteries is known as peripheral blood pressure (PBP). Usually, CBP and PBP are correlated. However, various types of shocks and cardiovascular disorders interfere with their regulation, and consequently, their correlation is lost. Therefore, understanding blood pressure in normal and disease conditions is essential for managing shock-related cardiovascular implications and improving treatment outcomes. 
  • 3.4K
  • 10 Feb 2023
Topic Review
Base
In chemistry, there are three definitions in common use of the word base, known as Arrhenius bases, Brønsted bases, and Lewis bases. All definitions agree that bases are substances which react with acids as originally proposed by G.-F. Rouelle in the mid-18th century. In 1884, Svante Arrhenius proposed that a base is a substance which dissociates in aqueous solution to form Hydroxide ions OH−. These ions can react with hydrogen ions (H+ according to Arrhenius) from the dissociation of acids to form water in an acid–base reaction. A base was therefore a metal hydroxide such as NaOH or Ca(OH)2. Such aqueous hydroxide solutions were also described by certain characteristic properties. They are slippery to the touch, can taste bitter and change the color of pH indicators (e.g., turn red litmus paper blue). In water, by altering the autoionization equilibrium, bases yield solutions in which the hydrogen ion activity is lower than it is in pure water, i.e., the water has a pH higher than 7.0 at standard conditions. A soluble base is called an alkali if it contains and releases OH− ions quantitatively. Metal oxides, hydroxides, and especially alkoxides are basic, and conjugate bases of weak acids are weak bases. Bases and acids are seen as chemical opposites because the effect of an acid is to increase the hydronium (H3O+) concentration in water, whereas bases reduce this concentration. A reaction between aqueous solutions of an acid and a base is called neutralization, producing a solution of water and a salt in which the salt separates into its component ions. If the aqueous solution is saturated with a given salt solute, any additional such salt precipitates out of the solution. In the more general Brønsted–Lowry acid–base theory (1923), a base is a substance that can accept hydrogen cations (H+)—otherwise known as protons. This does include aqueous hydroxides since OH− does react with H+ to form water, so that Arrhenius bases are a subset of Brønsted bases. However, there are also other Brønsted bases which accept protons, such as aqueous solutions of ammonia (NH3) or its organic derivatives (amines). These bases do not contain a hydroxide ion but nevertheless react with water, resulting in an increase in the concentration of hydroxide ion. Also, some non-aqueous solvents contain Brønsted bases which react with solvated protons. For example in liquid ammonia, NH2− is the basic ion species which accepts protons from NH4+, the acidic species in this solvent. G. N. Lewis realized that water, ammonia, and other bases can form a bond with a proton due to the unshared pair of electrons that the bases possess. In the Lewis theory, a base is an electron pair donor which can share a pair of electrons with an electron acceptor which is described as a Lewis acid. The Lewis theory is more general than the Brønsted model because the Lewis acid is not necessarily a proton, but can be another molecule (or ion) with a vacant low-lying orbital which can accept a pair of electrons. One notable example is boron trifluoride (BF3). Some other definitions of both bases and acids have been proposed in the past, but are not commonly used today.
  • 3.4K
  • 29 Sep 2022
Topic Review
May 29: First Successful Ascent of Mount Everest
On May 29, 1953, New Zealand mountaineer Edmund Hillary (later knighted) and Nepali Sherpa Tenzing Norgay became the first confirmed climbers to reach the 8,848-meter summit of Mount Everest as part of the ninth British expedition led by John Hunt (later Lord Hunt). Their successful ascent via the Southeast Ridge route (using the South Col as a high camp) marked the culmination of 30 years of British attempts on the mountain. The news reached Britain on June 2, coinciding with Queen Elizabeth II's coronation. Hillary was knighted and Norgay received the George Medal, with their achievement revolutionizing high-altitude mountaineering.
  • 3.4K
  • 27 May 2025
Topic Review
Chemical Industry in China
The chemical industry in China is one of China's main manufacturing industries. It valued at around $1.44 trillion in 2014, and China is currently the largest chemicals manufacturing economy in the world. The chemical industry is central to modern China's economy. It uses special methods to alter the structure, composition or synthesis of substances to produce new products, such as steel, plastic, and ethyl. Chemical industry provides building materials for China's infrastructure, including subway, high-speed train, and highway. Prior to 1978, most of the product was produced by the state-owned business, and the share in product outputted by state-owned business had decreased in 2002. The Chinese chemical industry is also one of the world's largest producers of both controlled and non-controlled precursor chemicals used in the Global illicit drug trade, particularly in the Golden Triangle as well as Latin America.
  • 3.4K
  • 26 Oct 2022
Topic Review
Autism
Kanner autism, or classic autism, is a neurodevelopmental disorder characterized by challenges with social communication, and by restricted and repetitive behaviors. It is now considered part of the wider autism spectrum. The term 'autism' was historically used to refer specifically to Kanner autism, which is the convention used in this entry, but it is now more commonly used for the spectrum at large. Parents often notice signs of autism during the first three years of their child's life. These signs often develop gradually, though some autistic children experience regression in their communication and social skills after reaching developmental milestones at a normal pace. Autism has been hypothesized to be associated with a combination of genetic and environmental factors. Risk factors during pregnancy include certain infections, such as rubella, toxins including valproic acid, alcohol, cocaine, pesticides, lead, and air pollution, fetal growth restriction, and autoimmune diseases. Controversies surround other proposed environmental causes; for example, the vaccine hypothesis, which although disproven, continues to hold sway in certain communities. Autism affects information processing in the brain and how nerve cells and their synapses connect and organize; how this occurs is not well understood. The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) combines forms of the condition, including high functioning autism (HFA), which was formerly known as Asperger syndrome, and pervasive developmental disorder not otherwise specified (PDD-NOS) into the diagnosis of autism spectrum disorder (ASD). Several interventions have been shown to reduce symptoms and improve the ability of autistic people to function and participate independently in the community. Behavioral, psychological, education, and/or skill-building interventions may be used to assist autistic people to learn life skills necessary for living independently, as well as other social, communication, and language skills. Therapy also aims to reduce challenging behaviors and build upon strengths. Some autistic adults are unable to live independently. An autistic culture has developed, with some individuals seeking a cure and others believing autism should be accepted as a difference to be accommodated instead of cured. Globally, autism is estimated to affect 24.8 million people (As of 2015). In the 2000s, the number of autistic people worldwide was estimated at 1–2 per 1,000 people. In the developed countries, about 1.5% of children are diagnosed with ASD (As of 2017), up from 0.7% in 2000 in the United States. It is diagnosed four to five times more often in males than females. The number of people diagnosed has increased considerably since the 1990s, which may be partly due to increased recognition of the condition.
  • 3.4K
  • 28 Sep 2022
Topic Review
Logistics Sprawl
The concentration of warehouses in peripheral regions of metropolitan areas in a time period is called logistics sprawl (LS).
  • 3.4K
  • 27 Nov 2020
Topic Review
Kamakhya
Kamakhya is an important Hindu Tantric goddess of desire who evolved in the Himalayan hills. She is worshiped as Siddha Kubjika, and is also identified as Kali and Maha Tripura Sundari. According to the Tantric texts (Kalika Purana, Yogini Tantra) that are the basis for her worship at the Kamakhya temple, a 16th-century temple in the Kamrup district of Assam. The earlier manifest of the goddess sanctified at the Garo hills is destroyed, although the Vatsayana priests are said to have carried away the manifest of the goddess to the Hindu kingdom in Kashmir and later sanctified in a remote hill forest in Himachal Pradesh. Her name means "renowned goddess of desire," and she resides at the presently rebuilt Kamakhya Temple in 1645 C. The temple is primary amongst the 51 Shakti Peethas related to the sect that follows Sati, and remains one of the most important Shakta temples and Hindu pilgrimage sites in the world.
  • 3.4K
  • 19 Oct 2022
Topic Review
Marsupial Lion
The marsupial lion (Thylacoleo carnifex) is an extinct species of carnivorous marsupial mammal that lived in Australia from the early to the late Pleistocene (1,600,000–46,000 years ago). Despite its name, it is not closely related to the lion, but is a member of the order Diprotodontia, one of the taxonomic groups of Australian marsupials.
  • 3.4K
  • 20 Oct 2022
Topic Review
Aquarius
Aquarius, a constellation of the zodiac, is rich in mythological and astrological significance. Representing the Water Bearer in ancient Greek mythology, Aquarius is celebrated for its association with the nurturing and life-giving element of water. Positioned along the celestial equator, this constellation captivates observers with its diverse array of celestial objects and its prominent role in the astrological tradition.
  • 3.4K
  • 29 Feb 2024
Topic Review Peer Reviewed
Passivhaus
Passivhaus or Passive House buildings are low-energy buildings in which the design is driven by quality and comfort, hence achieving acceptable levels of comfort through post-heating or post-cooling of fresh air. Additionally, Passivhaus building design follows the Passivhaus design criteria, as described in the Passive House Planning Package (PHPP). This article aims to introduce the Passivhaus background, development, and basic design principles. Finally, it also presents a brief description of the performance of Passivhaus buildings. 
  • 3.4K
  • 18 Apr 2022
Topic Review
Closed Ecological Life Support Systems
Closed ecological life support systems (CELSS) requires agricultural production for food, CO2removal, O2generation (human respiratory quotient ofCO2/[O2= 0.84–0.87 depending on the percentage formation of carbohydrate, fat and protein in the food consumed) and water recycling with bioreactors for recycling waste. Plants consume CO2and H2O for photosynthesis under the action of sufficient PAR to produce carbohydrate food, regenerate oxygen and filter water through evapotranspiration. There have been several bioregenerative life support system programmes including Biosphere 2 (US), CELSS (NASA), Bios-3 (Roscosmos) and its predecessors and MELiSSA (ESA).
  • 3.4K
  • 13 Aug 2021
Topic Review
Helianthus Annuus
Helianthus annuus, the common sunflower, is a large annual forb of the genus Helianthus grown as a crop for its edible oil and edible fruits. This sunflower species is also used as wild bird food, as livestock forage (as a meal or a silage plant), in some industrial applications, and as an ornamental in domestic gardens. The plant was first domesticated in the Americas. Wild Helianthus annuus is a widely branched annual plant with many flower heads. The domestic sunflower, however, often possesses only a single large inflorescence (flower head) atop an unbranched stem. The name sunflower may derive from the flower's head's shape, which resembles the sun. Sunflower seeds were brought to Europe from the Americas in the 16th century, where, along with sunflower oil, they became a widespread cooking ingredient.
  • 3.4K
  • 19 Oct 2022
Topic Review
Computer Designed Architecture and Architects
The designs generated by computer algorithms are becoming such a serious part of designers’ work that some are beginning to question whether they are more the work of computers than humans. There are also increasing suggestions that software development will eventually lead to a situation where humans in the profession will become redundant. This review article aims to present the currently used, implemented, and planned computer technologies employed in the design and consider how they affect and will affect the work of architects in the future.
  • 3.4K
  • 06 Sep 2021
Topic Review
Focused Ion Beam technology
Nanomaterials with unique structures and functions have been widely used in the fields of microelectronics, biology, medicine, and aerospace, etc. With advantages of high resolution and multi functions (e.g., milling, deposition, and implantation), focused ion beam (FIB) technology has been widely developed due to urgent demands for the 3D fabrication of nanomaterials. 
  • 3.4K
  • 21 Jun 2023
Topic Review
Concentration Cells Corrosion
In marine environments, microbial attacks on metallic materials result in microbiologically influenced corrosion (MIC), which could cause severe safety accidents and high economic losses. To date, MIC of a number of metallic materials ranging from common steels to corrosion-resistant ferrous alloys has been reported. The MIC process has been explained based on (1) bio-catalyzed oxygen reduction; (2) kinetics alternation of the corrosion process by increasing the mass transport of the reactants and products; (3) production of corrosive substances; and (4) generation of auxiliary cathodic reactants.
  • 3.4K
  • 16 Sep 2022
Topic Review
Synthesis of Thienothiophenes
Thienothiophenes (TT), formed by two annulated thiophene rings, represent fully the planar system, whose embedding into a molecular architecture can significantly improve/alter the fundamental properties of organic, π-conjugated materials. 
  • 3.4K
  • 21 Nov 2022
Topic Review
Business Process Outsourcing in the Philippines
One of the most dynamic and fastest growing sectors in the Philippines is the information technology–business process outsourcing (IT-BPO) industry. The industry is composed of eight sub-sectors, namely, knowledge process outsourcing and back offices, animation, call centers, software development, game development, engineering design, and medical transcription. The IT-BPO industry plays a major role in the country's growth and development.
  • 3.4K
  • 10 Oct 2022
Topic Review
Upāsaka and Upāsikā
Upāsaka (masculine) or Upāsikā (feminine) are from the Sanskrit and Pāli words for "attendant". This is the title of followers of Buddhism (or, historically, of Gautama Buddha) who are not monks, nuns, or novice monastics in a Buddhist order, and who undertake certain vows. In modern times they have a connotation of dedicated piety that is best suggested by terms such as "lay devotee" or "devout lay follower".
  • 3.4K
  • 23 Nov 2022
Topic Review
Bioevaluation of Artemisia judaica L. Plant’s Essential Oil
Artemisia judaica (ArJ) is a Mediterranean aromatic plant used traditionally to treat gastrointestinal ailments, skin diseases, atherosclerosis, and as an immuno-stimulant. Researches validate the curative role of ArJ in the treatment of skin wounds, which is attributed to its antioxidant and anti-inflammatory effects, as well as its high proportion of oxygenated monoterpenes and cinnamate derivatives.
  • 3.4K
  • 21 Feb 2022
Topic Review
History of the Portable Document Format (PDF)
The Portable Document Format was created in the early 1990s by Adobe Systems, introduced at the Windows and OS|2 Conference in January 1993 and remained a proprietary format until it was released as an open standard in 2008. Since then, it is under control of International Organization for Standardization Committee of volunteer industry experts. PDF was developed to share documents, including text formatting and inline images, among computer users of disparate platforms who may not have access to mutually-compatible application software.It was created by a research and developement team called Camelot, led by Adobe's co-founder John Warnock. PDF was one among a number of competing formats such as DjVu, Envoy, Common Ground Digital Paper, Farallon Replica and even Adobe's own PostScript format. In those early years before the rise of the World Wide Web and HTML documents, PDF was popular mainly in desktop publishing workflows. PDF's adoption in the early days of the format's history was slow. Adobe Acrobat, Adobe's suite for reading and creating PDF files, was not freely available; early versions of PDF had no support for external hyperlinks, reducing its usefulness on the Internet; the larger size of a PDF document compared to plain text required longer download times over the slower modems common at the time; and rendering PDF files was slow on the less powerful machines of the day. Adobe distributed its Adobe Reader (now Acrobat Reader) program free of charge from version 2.0 onwards, and continued supporting the original PDF, which eventually became the de facto standard for fixed-format electronic documents. In 2008 Adobe Systems' PDF Reference 1.7 became ISO 32000:1:2008. Thereafter, further development of PDF (including PDF 2.0) is conducted by ISO's TC 171 SC 2 WG 8 with the participation of Adobe Systems and other subject matter experts.
  • 3.4K
  • 14 Oct 2022
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