Search Index

Resources specific to A-levels to help students with revision. A-levels Are you a student currently studying A-levels, or looking to choose them in the near future? Read below for tips and guidance! You may also like: IB resources , University prep and Extra resources What are A-levels? Jump to resources A-levels, short for Advanced Level qualifications, are a widely recognised and highly regarded educational program typically taken by students in the United Kingdom (UK) and some other countries. They are usually studied in the final two years of secondary education, typically between the ages of 16 and 18. A-levels offer students the opportunity to specialise in specific subjects of their choice. Students typically choose three or four subjects to study, although this may vary depending on the educational institution. The subjects available can be diverse, covering areas such as sciences, humanities, social sciences, languages, and arts. How are A-levels graded? The A-level grading system is based on a letter grade scale in the UK. Here's an overview of the A-level grading system: Grades: A* (pronounced "A-star"): The highest grade achievable, demonstrating exceptional performance. A: Excellent performance, indicating a strong understanding of the subject. B: Very good performance, showing a solid grasp of the subject. C: Good performance, representing a satisfactory level of understanding. D: Fair performance, indicating a basic understanding of the subject. E: Marginal performance, showing a limited understanding of the subject. U: Ungraded, indicating that the student did not meet the minimum requirements to receive a grade. What are the benefits of studying A-level? A-levels provide students with a variety of advantages, such as a solid academic foundation for further education, the chance to focus on interest-specific areas, and flexibility in planning their course of study. Transferable abilities like critical thinking, problem-solving, and independent research are developed in A-levels, improving both prospects for entrance to universities and future employment opportunities. These widely respected credentials encourage intellectual vigour, intellectual curiosity, and a love of lifelong study. A-levels provide students with a strong foundation for success in higher education and a variety of career pathways, thanks to their academic rigour and global renown. Resources for revision Web sites to hel p Maths / Maths and Further Maths Chemistry / Chemrevise / Chemguide Biology / Quizzes Physics: A-level Physics / Isaac Physics Computer Science topic-by-topic Teach Computer Science Psychology All subjects / Seneca Learning / Save My Exams Physics and Maths Tutor YouTube channels to hel p Chemistry- Allery Chemistry and Eliot Rintoul Past p apers Biology, Chemistry, Physics, Maths Textbooks (depend on exam board) CGP range for Bio, Chem, Phys, and Maths- exam practice workbooks

The secrets of the brain are secrets no longer; the field of neuroscience is rapidly expanding day by day. Read articles which discuss Parkinsonism, Huntington’s, degeneration, Alzheimer’s, and more. Neuroscience Articles The secrets of the brain are secrets no longer; the field of neuroscience is rapidly expanding day by day. Read articles which discuss Parkinsonism, Huntington’s, degeneration, Alzheimer’s, and more. You may also like: Biology , Immunology , Medicine Synaptic plasticity and London taxi drivers Synaptic plasticity and navigating our surroundings Stress and neurodegeneration And how the hormone cortisol plays a significant role Markers for Parkinsonism Exploring the role of TDP43 The wonders of the human brain A basic overview of brain function The brain-climate connection Can rising temperatures really affect our brains? Schizophrenia and accelerated ageing A complex medical phenotype Squid axons And how they were fundamental to discoveries in neuroscience Alzheimer's disease Its pathology and potential treatment Serial killers Their neurological basis Huntington's disease A rare, inherited, debilitating neurological disease Electricity in the body Luigi Galvani 's work PTSD and intrusive memories Article #1 in a series on Post Traumatic Stress Disorder and traumatic memories Mobility disorders Hypermobility spectrum disorders vs. Hypermobile Ehler-Danos Syndrome Brief neuroanatomy of autism Autism is a neurological and developmental disorder Oliver Sacks Who was this famous neuroscientist? A treatment for Huntington's disease Antisense oligonucleotide gene therapy PTSD and Tetris Article #2 in a series on Post Traumatic Stress Disorder and traumatic memories The dopamine connection The link between the brain and the digestive system Neuromyelitis optica (NMO)- Devic disease How is it different to Multiple Sclerosis? Article #8 in a series on Rare diseases. DFNB9 How was this form of deafness treated for the first time? Next

Obesity is one of the most common problems among many in all age groups. As per world health organisation obesity or overweight defined as abnormal or excessive fat accumulation that may cause impair health. Obesity measured by BMI (Body mass index), normal BMI for children is  range Go back Facebook X (Twitter) WhatsApp LinkedIn Pinterest Copy link Childhood obesity Last updated: 18/11/24 Published: 25/03/23 Obesity is one of the most common problems among many in all age groups. As per the World Health Organisation, obesity or overweight is defined as abnormal or excessive fat accumulation that may cause impaired health. Obesity is measured by Body Mass Index (BMI). The normal BMI for children ranges from 13.53 to 20.08. Children are the most vulnerable age group for becoming overweight. Early prevention reduces the overall burden of health care system globally. Obesity causes: Obesity mainly results from imbalance between energy intake and utilisation of calorie intake. There are several reasons for becoming overweight. Five main causes for overweight are- Genetic factors Food quality and quantity Parental belief Sedentary lifestyle Environmental resource Symptoms of childhood obesity: Shortness of breath while physical activity Difficulty in breathing while sleeping. Easily fatigue. Gastric problems such as gastroesophageal reflux disease Fat deposits in various body parts such as breast, abdomen and thigh area Prevalence The prevalence of overweight children is increasing every year. In England, in the year 2019/2020, the prevalence of overweight increased rapidly. The National Child Measurement Program measure shows that in Reception (4-5 years old), the obesity rate was 9.9% and continued to increase to 21% in year 6. Childhood obesity is tackled early so complications can be managed before it worsens. There are many ways to prevent childhood obesity. Prevention The National Institute for Health and Care Excellence guidance currently recommends lifestyle intervention as the main treatment for prevention of childhood obesity. Diet management and physical activity are the main areas to focus on for obesity prevention. Dietary modification includes limited use of refined grains and sweets, potatoes, red meat, processed meat, sugary drinks, and alternatively increase intake of fresh fruits and vegetables, whole grain and adopt more healthier food options, instead of fatty and junk food. On top of that, add physical activity in daily routine. It is one of the key factors for reduction of obesity. Another way for communities to tackle obesity is to take part in government programmes such as Healthier You and NHS Digital weight management programme, which are helpful for handling obesity. Written by Chhaya Dhedhi Related articles: Depression in children / Childhood stunting in developing nations / Nature vs nurture in childhood intelligence

Peruse through the current treatment discoveries for one of the deadliest diseases in the world. Learn about the factors that cause tumour growth, metastatic processes and blastomas. Cancer Articles Peruse through the current treatment discoveries for one of the deadliest diseases in the world. Learn about the factors that cause tumour growth, metastatic processes and blastomas. You may also like: Biology, Medicine Arginine and tumour growth Another breakthrough in cancer research Unveiling the cancer magnet Stem cells in vertebral bones can act like cancer magnets for spinal tumour metastasis COMING SOON COMING SOON Previous

Resources to help you prepare for university admission. Entrance Exam Preparation Resources to help you with university admission for: medicine , dentistry, natural sciences , physics , maths , engineering . Do note these entrance exams are mainly for UK universities, but can be used for international unis too. It is advised to check with the university when applying. You may also like: A-level resources, IB resources and Extra resources MEDICINE: University Clinical Aptitude Test (UCAT) UCAT resources: UCAT website / The Medic Portal / 6med UCAT Books: 1300 UCAT Practice Questions / 1250 UKCAT Practice Questions / UCAT 700+ UCAT online course: Medify Help with medical exams DENTISTRY: UCAT and BioMedical Admissions Test (BMAT; for University of Leeds only) Dentistry application preparation BMAT: online mastery course / Medify guide / Past papers / 700 BMAT Practice Questions / BMAT ebook For UCAT resources, see above OTHER ADMISSION TESTS Engineering: STEP / PAT University of Cambridge: natural sciences (NSAA) / engineering (ENGAA) / maths (STEP) / physics (PAT)

Cortisol is a glucocorticoid steroid hormone produced by the zona fasciculata segment of the adrenal gland, following stimulation by the release of adrenocorticotropic hormones from the pituitary gland. Chronic stress is associated with excessive cortisol production and the development of neurodegenerative diseases.  Go Back Facebook X (Twitter) WhatsApp LinkedIn Pinterest Copy link Stress and neurodegeneration Last updated: 30/01/25 Published: 10/03/23 Cortisol is a glucocorticoid steroid hormone produced by the zona fasciculata segment of the adrenal gland, following stimulation by the release of adrenocorticotropic hormones from the pituitary gland. Chronic stress is associated with excessive cortisol production and the development of neurodegenerative diseases. Once cortisol is produced and released into circulation, it crosses the blood-brain barrier to bind to and activate nuclear glucocorticoid receptors (GR) in the hippocampus. Upon cortisol binding, the GR undergoes conformational changes, causing it to dissociate from its chaperone complex and consequently allowing for the transcription of target genes. One such pathway that is activated as a result of GR binding is the brain-derived neurotrophic factor (BDNF) and the cAMP response element-binding protein (CREB) pathway, which is important for long-term memory formation and consolidation. However, memory formation can be impaired following abnormal BDNF/ CREB pathway activation due to elevated cortisol levels. Moreover, high cortisol levels have been found to cause increased amyloid-beta (AB) deposition, which is evident in Alzheimer's disease patients. Therefore, increased blood cortisol levels result in increased activation of GR, causing impaired gene expression and affecting cellular functions. When GR are exposed to cortisol over a long period of time, such pathways become further impaired, resulting in the characteristic neurodegenerative disease pathology in affected individuals. A study conducted by Kline et. al assessed the relationship between high cortisol levels and neurodegenerative disease pathology in mice. In this study, it was noted that chronic stress reduced the diversity of the gut microbiome in mice, and such alterations resulted in increased gut permeability, promoting the movement of pathogens across the epithelial lining, and increasing AB deposition in affected mice. However, AB deposition can be reduced if cortisol levels are controlled. For example, xanamem, a drug currently in clinical trials, reduces cortisol levels by inhibiting the 11B-hydroxysteroid-1 ezyme, known to play a role in the activation of cortisol via the hypothalamus-pituitary-adrenal axis. Therefore, xanamem or similar compounds, if suitable following clinical testing, could be a means of decreasing AB deposition, thereby targeting one component of neurodegnerative disease pathology. If the putative hypotheses of Alzheimer's disease aetiology are correct, this would potentially ameliorate patient symptoms and offer a degree of improved quality of life for affected individuals. Written by Maria Zareef Kahloon Related articles: Tetris and PTSD / Mental health awareness / Physical and mental health

Pisaster ochraceus (also known as ‘ochre stars’) is a keystone species and common starfish found in the Pacific Ocean and are very interesting species to research on. They are found mainly in Alaska and Baja California. Their size range from 15 to 36cm in diameter come in different ranges of colours eg: red, yellow, orange and purple. Go back Facebook X (Twitter) WhatsApp LinkedIn Pinterest Copy link Designing an experiment on sea stars Last updated: 17/11/24 Published: 25/03/23 Title: How do light and dark rocky surfaces affect the relative fitness of the orange and purple ochre stars? Pisaster ochraceus (also known as ‘ochre stars’) is a keystone species and common starfish found in the Pacific Ocean and are very interesting species to research on. They are found mainly in Alaska and Baja California. Their size range from 15 to 36cm in diameter come in different ranges of colours eg: red, yellow, orange and purple. They are mainly found near rocky shores and found under rocks and in crevices in the low and intertidal zones and they often cluster together. They are simple organisms, they do not have brain or ganglia and around its mouth there is a nerve ring which connects with 5 radial nerves. The population of Pisaster ochraceus that are orange are 6- 28%, whilst majority are purple and researchers have seen that mainly genetic traits cause these species to have different colours whilst they develop. There have also been experiments that examined how colour changes across the geographic range. Figure 1: Image of purple and orange ochre stars The aim of the experiment would be to see how either light or dark rocky surfaces affect the relative fitness of the orange and purple ochre stars, meaning their offspring. The relative fitness shows how much fitness there is in a genotype compared to the maximum fitness. Before starting this experiment, a risk assessment has to be done to make sure it is safe and increases hazard awareness when the experiment is being done. The likelihood, severity and risk has to be looked into during the assessment and how to reduce the risk. One example is, doing the experiment by the shores can be risky due to wind waves and tides and so appropriate footwear has to be worn and the weather should be looked into before going to do this experiment. There are going to be control variables such as: season, quadrat area, number of samples calculated and same equipment being used throughout the whole day so validity would be affected. The uncontrolled variables would be: temperature, pH of seawater and predators that consume Pisaster ochraceus . In order to see how the Pisaster ochraceus are affected, 10 - 15 sites should be chosen and a quadrat can be used (10 metres by 10 metres) on each site and running parallel by using a tape measure on darker rocky surfaces and then after on lighter rocky surfaces. This will be useful as you can see the distribution. Place 15 quadrats randomly over each area in every site to work out the abundance. Within each quadrat, orange and purple Pisaster ochraceus are counted separately to illustrate the set of results with the different colours and the rocky surfaces on a table of results. After collecting the results, this should be shown on a set of tables and then placed on a stratified bar graph showing all the sites, the colour of the starfish (on the x- axis) and results of relative fitness(on the y-axis) showing a good visualisation of the experiment. A paired t-test should be done as we want to see the difference between two variables which are the light and dark rocky surfaces for the same sample which is the colour of the starfish through their means. It should then be concluded by seeing which morph has a higher relative fitness and conclude to see if there is an effect. If the p-value is lesser or equal to the significance value, then the hypothesis should be rejected if the p-value is higher than the significance value the hypothesis should be accepted. Figure 2: Purple and orange ochre stars on rocky surfaces Carrying out an experiment in a natural environment is an advantage as this can be reflected on real life therefore having higher ecological validity. However, doing this experiment can have some disadvantages, even though this is cost-effective and done in a natural environment, we do not know how reliable these results will be because the collection of results can have some inaccuracy. Also, it also has to be understood that many other biotic and abiotic factors can affect this experiment. As it is done in the natural environment there will be issues with Pisaster ochraceus being predated by sea otters or even seagulls which can have an effect on results and also making it less generalisable. Air temperature and water temperature can also have an effect on these species as well and it cannot be controlled which can create issues on results. Also, by using a quadrat, it can be prone to human errors (miscounting or overcounting) and having randomly spaced quadrats, can miss out individual species therefore showing under-representative estimates and results in the populations of the Pisaster ochraceus . More repeats would have to be done throughout the years to collect more accurate results and also be tested by other variables such as temperature, wave exposure and even pH of seawater to see if this also affects relative fitness of Pisaster ochraceus with different colouration. It is important to think about the ethical considerations as it is a natural area and these species organisms live there and it should not be damaged before, during and after the experiment. The creatures must be respected as well as the environment they live in. With many equipment being used, it is vital not to interfere with the organisms, create litter or disturb the habitat as it will be unethical. In conclusion, this experiment is effective as it is done in a natural environment at different sites but it will be time consuming due to changes in weather and working out the abundance over all the sites for a long period of time. By doing the paired t-test, a difference in the two means can be seen and create smaller effects on error from the samples. Written by Jeevana Thavarajah Related articles: An experiment on castor oil / on pendulums REFERENCES The Biological Bulletin. 2022. Color Polymorphism and Genetic Structure in the Sea Star Pisaster ochraceus | The Biological Bulletin: Vol 211, No 3. [online] Available at: [Accessed 18 January 2022]. Animal Diversity Web. 2022. Pisaster ochraceus. [online] Available at: [Accessed 18 January 2022]. Sanctuarysimon.org. 2022. SIMoN :: Species Database. [online] Available at: [Accessed 18 January 2022]. Rgs.org. 2022. Royal Geographical Society - Fieldwork in schools. [online] Available at: [Accessed 18 January 2022].

Scientia News is full of STEM blogs, articles and resources freely available across the globe for students. Browse all of our fascinating content written by students and professionals showing their passion in STEM and the other sciences. Log In Welcome to Scientia News DELIVERING INFORMATIVE CONTENT Scientia News is full of STEM blogs, articles and resources freely available across the globe for students. Browse all of our fascinating content written by students and professionals showing their passion in STEM and other sciences. We hope this platform helps you discover something that inspires your curiosity, and encourages you to learn more about important topics in STEM. Meet the Official Team NAVIGATE AND CLICK THE PHOTOS BELOW TO LEARN MORE ABOUT US! To play, press and hold the enter key. To stop, release the enter key. To play, press and hold the enter key. To stop, release the enter key. To play, press and hold the enter key. To stop, release the enter key. Latest Articles physics Basics of transformer physics View More cancer Unveiling the cancer magnet: vertebral stem cells and spinal tumour metastasis View More zoology Emperor penguins, the kings of the ice View More medicine Sleep less…remember less: the hidden link between sleep and memory loss View More CONTACT CONTACT US Scientia News welcomes anyone who wants to share their ideas and write for our platform. If you are interested in realising your writing potential with us AND live in the UK; and/ or would like to give feedback: Email us at scientianewsorg@gmail.com or fill in our GET IN TOUCH form below and we'll be in contact... Follow us on our socials for the latest updates. Comment, like and share! Join our mailing list below for latest site content. You can also sign up to become a site member . SUBSCRIPTION Join our mailing list to receive alerts for new articles and other site content. Be sure to check your spam/ junk folders in case emails are sent there. Email Subscribe GET IN TOUCH First Name Last Name Email Message Send Thanks for submitting!

An introductory and comprehensive review of complex diseases and their environmental influences. Using schizophrenia as an example, we are interested in exploring one of the biggest questions that underlie complex diseases. Go Back Facebook X (Twitter) WhatsApp LinkedIn Pinterest Copy link The environment on complex diseases: schizophrenia Last updated: 18/11/24 Published: 08/05/23 An introductory and comprehensive review of complex diseases and their environmental influences. Using schizophrenia as an example, we are interested in exploring one of the biggest questions that underlie complex diseases. Introduction: Not Exactly a Yes or No Question Many things in science revolve around questions. It is remarkable to find the number of questions left for scientists to answer or those that will remain unanswered. Indeed, one of the most daunting tasks for any scientist would be to see through every detail of a piece of information, even if everyone has seen it, but with different sets of lenses and asking different sets of questions. After all, “why did the apple fall from its tree?”. However, asking questions is one thing. Finding answers and, more importantly, the evidence or proof that supports them does not always yield conclusive results. Nevertheless, perhaps some findings may shine a new light on a previously unanswered question. We can categorise the study of genetics into two questions: “What happens if everything goes well?” and “What happens if it goes wrong?”. Whilst there are virtually limitless potential causes of any genetic disease, most genetic diseases are known to be heritable. A mutation in one gene that causes a disease can be inherited from the parents to their offspring. Often, genetic diseases are associated with a fault in one gene, known as a single-gene disorder, with notorious names including Huntington’s disease, cystic fibrosis, sickle cell anaemia, and familial hypercholesterolaemia. These diseases have different mechanisms, and the causes are also diverse. But all these diseases have one thing in common: they are all caused by a mutation or fault in one gene, and inheriting any specific genes may lead to disease development. In other words, “either you have it, or you do not”. The role of DNA and mutations in complex diseases. Image/ craiyon.com Multifactorial or complex diseases are a classification geneticists give to diseases caused by factors, faults or mutations in more than one gene. In other words, a polygenic disease. As a result, the research, diagnosis, and identification of complex diseases may not always produce a clear “black-and-white” conclusion. Furthermore, complex diseases make up most non-infectious diseases known. The diseases associated with leading causes of mortality are, in their respective ways, complex. Household names include heart diseases, Alzheimer’s and dementia, cancer, diabetes, and stroke. All of these diseases may employ many mechanisms of action, involving multiple risk factors instead of direct cause and effect, using environmental and genetic interactions or factors to their advantage, and in contrast to single-gene disorders, do not always follow clear or specific patterns of inheritance and always involve more than one problematic genes before the complete symptoms manifest. For these reasons, complex diseases are infamously more common and even more challenging to study and treat than many other non-infectious diseases. No longer the easy “yes or no” question. The Complex Disease Conundrum: Schizophrenia Here we look at the case of a particularly infamous and, arguably, notorious complex disease, schizophrenia (SCZ). SCZ is a severely debilitating and chronic neurodevelopmental disorder that affects around 1% of the world’s population. Like many other complex diseases, SCZ is highly polygenic. The NHS characterise SCZ as a “disease that tends to run in families, but no single gene is known to be directly responsible…having these genes does not necessarily mean one will develop SCZ”. As previously mentioned, many intricate factors are at play behind complex diseases. In contrast, there is neither a single known cause for SCZ nor a cure. Additionally, despite its discovery a century ago, SCZ is arguably not well understood, giving a clue to the sophisticated mechanisms that underlie SCZ. To further illustrate how such complexities may pose a challenge to future medical treatments, we shall consider a conundrum that diseases like SCZ may impose. The highly elaborate nature of complex diseases means that it is impossible to predict disease outcomes or inheritance with absolute certainty nor rule out potential specific causes of diseases. One of the most crucial aspects of research on complex diseases is their genetic architecture, just as a house is arguably only as good as its blueprint. Therefore, a fundamental understanding of the genes behind diseases can lead to a better knowledge of diseases’ pathogenesis, epidemiology, and potential drug target, and hopefully, one day bridge our current healthcare with predictive and personalised medicine. However, as mentioned by the NHS, one of the intricacies behind SCZ is that possessing variants of diseased genes does not translate to certainty in disease development or symptom manifestation. Our conundrum, and perhaps the biggest question on complex diseases like SCZ is: “Why, even when an individual possesses characteristic genes of a complex disease, they may not necessarily exhibit symptoms or have the disease?”. The enigma surrounding complex diseases lies in the elegant interactions between our genes, the blueprint of life, and “everything else”. Understanding the interplay of factors behind complex diseases may finally explain many of the intricacies behind diseases like SCZ. Genes and Environment: an Obvious Interaction? The gene-environment important implications on complex disease development were demonstrated using twin studies. A twin study, as its name suggests, is the study of twins by their similarities, differences, and many other traits that twins may exhibit to provide clues to the influences of genetic and external factors. Monozygotic (MZ) twins each share the same genome and, therefore, are genetically identical. Therefore, if one twin shows a phenotype, the other twin would theoretically also have said genes and should exhibit the corresponding trait. Experimentally, we calculate the concordance rate, which means the probability of both twins expressing a phenotype or characteristic, given that one twin has said characteristic. Furthermore, the heritability score may be mathematically approximated using MZ concordance and the concordance between dizygotic twins (twins that share around half a genome). These studies are and have been particularly useful in demonstrating the exact implications genetic factors have on phenotypes and how the expression of traits may have been influenced by confounding factors. In the case of SCZ, scientists have seen, over decades, a relatively low concordance rate but high heritability score. A recent study (published in 2018) through the Danish SCZ research cohort involved the analysis of around 31,500 twins born between the years 1951 and 2000, where researchers reported a concordance rate of 33% and estimated heritability score of 79%, with other older studies reporting a concordance rate up to and around 50%. The percentages suggest that SCZ is likely to be passed down. In other words, a genetically identical twin only has approximately 1 in 2 risks of also developing symptoms of SCZ if its opposite twin also displays SCZ. The scientists concluded that although genetic predisposition significantly affects one’s susceptibility or vulnerability against SCZ, it is not the single cause of SCZ. Demographically, there have been studies that directly link environmental risks to SCZ. Some risk factors, such as famines and malnutrition, are more evident than others. However, some studies also associate higher SCZ risk among highly industrialised countries and first or second-generation migrants. For instance, few studies point out an increased risk of SCZ within ethnic minorities and Afro-Caribbean immigrants in the United Kingdom. Hypotheses that may explain such data include stress during migration, potential maternal malnutrition, and even exposure to diseases. With this example, hopefully, we all may appreciate how the aetiology of SCZ and other complex diseases are confounded by environmental factors. In addition, how such factors may profoundly influence an individual’s genome. SCZ is a clear example of how genetic predisposition, the presence of essential gene variants characteristic of a disease, may act as a blueprint to a terrible disease waiting to be “built” by certain factors as if they promote such development. It is remarkable how genetic elements and their interactions with many other factors may contribute almost collectively to disease pathogenesis. We can reflect this to a famous quote amongst clinical geneticists: “genetics loads the gun, and environment pulls the trigger.” Carrying high-risk genes may increase the susceptibility to a complex disease, and an environment that promotes such disease may tip the balance in favour of the disease. However, finding and understanding the “blueprints” of SCZ, what executes this “blueprint”, and how it works is still an area of ongoing research. Furthermore, how the interplay between genetics and external factors can lead to profound effects like disease outcomes is still a relatively new subject. The Epigenome: the Environment’s Playground To review, it is clear that genes are crucial in complex disease aetiology. In the case of SCZ, high-risk genes and variances are highly attributed to disease onset and pathogenesis. However, we also see with twin studies that genetics alone cannot explain the high degree of differences between twins, particularly when referring to SCZ concordance between identical twins. In other words, external factors are at play, influencing one’s susceptibility and predisposition to SCZ. These differences can be explained by the effects epigenetics have on our genome. Epigenetic mechanisms regulate gene expression by modifying the genome. In short, on top of the DNA double strands, the genome consists of additional proteins, factors, and even chemical compounds that all aid the genetic functions our body heavily relies on. The key to epigenetics lies in these external factors’ ability to regulate gene expression, where some factors may promote gene expression whilst others may prevent it. Epigenetic changes alter gene functions as they can turn gene expression “on” and “off”. Furthermore, many researchers have also shown how epigenetic changes may accumulate and be inherited somatically with cell division and even passed down through generations. Therefore, epigenetic changes may occur without the need to change any of the DNA codes, yet, they may cause a profound effect by controlling gene expression throughout many levels of the living system. These underlying mechanisms are crucial for the environment’s effect on complex diseases. Some external factors may directly cause variances or even damage to the genome (e.g. UV, ionising radiation), and other sources may indirectly change gene expression by manipulating epigenetic changes. The exact molecular genetics behind epigenetic mechanisms are elaborate. However, we can generally find three common epigenetic mechanisms: DNA Methylation, Histone Modification, and Non-coding RNA. Although each method works differently, they achieve a common goal of promoting or silencing gene expression. All of these are done by the many molecular components of epigenetics, altering the genome without editing the gene sequence. We refer to the epigenome, which translates to “above the genome”, the genome itself and all the epigenetic modifiers that regulates gene expression on many levels. Environmental factors and exposure may influence epigenetic mechanisms, affecting gene expression in the cell or throughout the body, sometimes permanently. Therefore, it is clear how the epigenome may change throughout life as different individuals are exposed to numerous environmental factors. Furthermore, each individual may also have a unique epigenome. Depending on which tissues or cells are affected by these mechanisms, tissues or cells may even have a distinct epigenome, unlike the genome, which is theoretically identical in all cells. One example of this is the potential effects of DNA methylation on schizophrenia epidemiology. DNA methylation can silence genes via the enzymes DNA methyltransferases (DNMT), a family of enzymes capable of catalysing the addition of methyl groups directly into the DNA. The DNMT enzymes may methylate specific nucleotides on the gene, which usually would silence said gene. Many researchers have found that the dysregulation of DNA methylation may increase the risk towards the aetiology of numerous early onset neuro-developmental disorders. However, SCZ later-onset development also points towards the influence of environmental risk factors that target DNA methylation mechanisms. Studies show links between famines and SCZ increased prevalence, as the DNMT enzymes heavily rely on nutrients to supply essential amino acids. Malnutrition is thought to play a considerable role in DNA methylation changes and, therefore, the risk of SCZ. Small Piece of a Changing Puzzle Hopefully, we can see a bigger picture of the highly intricate foundation beneath complex diseases. Bear in mind that SCZ is only one of many complex diseases known. SCZ is ultimately not a pristine and impartial model to study complex disorders. For instance, concordance rates of complex diseases change depending on their genetic background. In addition, they may involve different mutations, variance, or dysregulation of differing pathways and epigenetic mechanisms. After all, complex diseases are complex. Finally, this article aimed to give a rundown of the epigenetics behind complex diseases like SCZ. However, it is only a snapshot compared to the larger world of the epigenome. Furthermore, some questions remain unanswered: the genetic background and architecture of complex diseases, and ways to study, diagnose, and treat complex diseases. This Scientia article is one of the articles in Scientia on the theme of complex disease science and genetics. Hopefully, this introductory article is an insight and can be used to reflect upon, especially when tackling more complicated subjects of complex diseases and precision medicine. Written by Stephanus Steven Related articles: Schizophrenia, Inflammation, and Accelerated Ageing / An Introduction to Epigenetics

Chemistry is such a diverse science branching into many industries and its understanding is fundamental in unlocking solutions to overcome diseases, viruses and infections. The science has a central application in the pharmaceutical drug manufacturing process. In medicine, Chemistry helps understand diseases and medical samples through the various analytical and instrumental methods – which in turn aids medical research and the development and discovery of drugs. Go back Facebook X (Twitter) WhatsApp LinkedIn Pinterest Copy link The role of chemistry in medicine Last updated: 17/11/24 Published: 13/04/23 Chemistry is such a diverse science branching into many industries and its understanding is fundamental in unlocking solutions to overcome diseases, viruses and infections. The science has a central application in the pharmaceutical drug manufacturing process. In medicine, chemistry helps understand diseases and medical samples through the various analytical and instrumental methods – which in turn aids medical research and the development and discovery of drugs. Chemical synthesis has allowed scientists to synthesise new compounds which can be used to treat a range of diseases and medical conditions. The study and knowledge of chemistry is very essential for professionals involved in the healthcare sector including doctors and nurses. The fact is that it cannot be denied that chemistry plays a dominant role in the day-to-day life of a healthcare professional. With the help of chemistry alongside biochemistry and biology, diseases and disorders can be easily diagnosed. The knowledge of chemistry has allowed for the understanding of the science behind pregnancy tests and COVID-19 PCR tests using UV-VIS Spectroscopy. Chemistry also plays a key role in the development of new medical technologies, such as diagnostic tools and imaging equipment. Magnetic resonance imaging (MRI) relies on principles of chemistry and is an application of nuclear magnetic resonance (NMR), an analytical tool for chemists found in laboratories. The technique uses strong magnetic fields and radio waves to produce detailed images of organs and body tissues. The scan uses contrast agents using elements iron and gadolinium to enhance the clarity of images. Overall, chemistry is an essential discipline for advancing our understanding of health and disease, and for developing new treatments and technologies to improve human health. Interesting fact: vaccines for rabies and anthrax were discovered by Louis Pasteur – a famous chemist. Written by Khushleen Kaur Related articles: AI in medicinal chemistry / The role of chemistry in space