X ray Crystallography of crystals: Beginning of a new scientific era

Rafat Shahriar Islam

Around 100 years ago William Henry Bragg and his son William Lawrence Bragg used Sodium Chloride crystal to pass x ray beams through it that created a beautiful geometric pattern on a photographic paper placed behind it.

Being inspired by the experiment of Rosalind Franklin in 1953 producing images (also known as photograph 51) of crystal DNA from X ray, Watson & Crick described the double helical structure of DNA by ‘Diffraction pattern analysis’.

X-rays are electromagnetic radiation with wavelengths between about 0.02 Å and 100 Å. Because X-rays have wavelengths similar to the size of atoms, they are used to explore within crystals. Today it is scientifically established that X rays hitting these particulates obstacles interpret the atoms inside a crystal lattice to give a structure of regular geometric patterns.

X ray diffraction analysis is mainly diffraction pattern that is observed when the shower of electrons after diffracting the X ray pass through a crystal unit. Electron density map can be obtained from these diffraction patterns. These maps show contour lines of electron density. Since electrons more or less surround atoms uniformly, it is possible to determine where atoms are located. To get a three-dimensional picture, the crystal is rotated with a view to getting a three-dimensional picture in together with a detector connected to a computer producing two-dimensional electron density maps for each rotation.

Unfortunately, there is no known way to focus x-rays with a lens, unlikely with visible lights. Until then it is necessary to use crystals to diffract x-rays and create a diffraction pattern which can be interpreted mathematically by a computer. This turns the computer into a virtual lens to help us look at the structure of a molecule. Crystals have a repeated cell unit within them and so the x-ray diffraction from one unit cell would not be significant. Fortunately, a good crystal diffraction pattern is observed which is amplified enough to produce a 3D picture in a detector due to multiple cell units within a crystal.

There are various methods of growing protein crystals for x ray diffraction analysis:

Vapor Diffusion – (Hanging Drop Method)

The most common ways of crystal growth where a drop of protein solution is suspended over a reservoir containing buffer and precipitant. Water diffuses from the drop to the solution leaving the drop with optimal crystal growth conditions.

Batch crystallization

Crystals are grown by keeping a saturated protein solution put in a sealed container.

Microbatch crystallization

By lowering the saturation over time, diffusion of proteins into the oil is made happen by putting a drop of protein solution in inert oil and let the crystal grow.


By growing a crystal in a highly saturated solution and then placing it in a less saturated one to let the crystal growth happen.


A few crystals are grown, then crushed, and put into a final solution that combines them into a few nice crystals. This involves quite a bit of experimentation with solutions’ concentrations to get the desired number of crystals.

Free interface diffusion

A container has levels of varying saturation. Crystals form initially in the highly saturated part, but as the solution mixes, it eventually only supports crystal growth.


Similar to the previous, but with a semipermeable membrane separating the layers.

How does X ray crystallography work?

  1. X-ray beams are shot through a crystal of the atom keeping the crystal mounted to a Goniometer to keep it in place during the operation
  2. X-Ray after being diffracted through the crystal lattice leads the beam in a pattern based on their structure.
  3. A diffraction pattern is then finally observed.

Advantages of x ray crystallography technique:

  1. The nondestructive nature of X ray makes it suitable to characterize metals.
  2. Knowing the wavelength and diffraction angle and with the use of Bragg’s law, information on the crystalline condition of the sample, and thus phase proportions; texture and degree of preferred orientation can be calculated.
  3. Plastic strain and particle size can be interpreted using peak width.

Limitations of X ray crystallography technique:

Crystallizing Protein:

  1. Fragile
  2. Requires a crystal with the shortest side of 0.2 mm
  3. Crystallization may require conditions that may not be physiological.

Flaws of Crystallization:

  1. Disorder in Unit Cell
  2. Vibrations of molecules
  3. Distortion in crystallization
  4. Diffraction peaks are very crowded for complex macromolecules and are difficult to separate.
  5. Heavy atom substitution works for molecules larger than 600 atoms, so a gap is present for molecules in the intermediate size range.

Applications of X ray crystallographic technique:

  1. It is used to study materials such as salts, metals as well as various biological molecules etc. that can form crystal lattice structure.
  2. To determine the electron density, the mean positions of the atoms in the crystal, their chemical bonds, their disorders etc.
  3. To detect the size of atoms, and types of chemical bonds, and the atomic scale differences among various materials, especially minerals and alloys. The method also revealed the structure and function of many biological molecules, including vitamins, drugs, proteins and nucleic acids such as DNA
  4. To identify the atomic structure of new materials that may seem similar in other experiments
  5. X ray crystal structures can also account for unusual electronic or elastic properties of a material and also serve as the basis for designing pharmaceuticals against diseases.

The specificity of the protein’s active sites and binding sites is completely dependent on the protein’s precise conformation. X-ray crystallography can reveal the precise three-dimensional positions of most atoms in a protein molecule because x-rays and covalent bonds have a similar wavelength, and therefore currently provides the best visualization of protein structure. At present, this technique is helping the researchers to elucidate the folding of secondary protein residual structures depending on various external factors.

Rafat Shahriar Islam, is a graduate from Department of Pharmacy, East West University.  He can be reached at rafat.islam46@gmail.com

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Can Artificial Intelligence Beat Human Intelligence?

Tilova Sumaiya

Lots of controversies I almost always hear about that “Does Artificial intelligence (AI) beat human intelligence?”  Yes, definitely this question comes in our mind since we can see the maximum capabilities of AI. At this era where we’re standing, we can say that Artificial Intelligence is a miracle invention of human brains.  We will be able to depend on it almost entirely within a very short time that we can predict. It has made possible lots of impossible things which were beyond our imaginations. So in my today’s writing, I’ll try to solve the answer for those who are more curious to know about this answer, based on few logics and illustrations.

In a short, we can say Artificial Intelligence is an intelligence which is been developed by a software or a machine. AI research is highly technical and specialized and is deeply divided into sub fields that often fail to communicate with each other. AI research is also divided by several technical issues. A few sub fields focus on to solve the critical reasoning. The Supreme area and problem where Artificial intelligence is working are reasoning, knowledge, planning, learning, natural language processing, perception and the ability to move and manipulate objects. The more areas include recently which are statistical methods, computational intelligence, and traditional symbolic Artificial intelligence. Artificial intelligence has another core part which is machine learning. Machine learning and data science are both dominating modern world. Different Startup’s around the world which is focusing on machine learning & data science, exploring new business innovations and bring success with the combination of both. Recently Microsoft has cited a study that noted over the past two years, above $1 billion of venture capital invested in machine learning & data science. For the new cohort about cognitive technologies which is considered one of the prominent technologies of future, Microsoft made a cross country tour in US & Canada across twelve cities to select 10 new Startup for investment.

It’s been an almost millennium, we have been hearing lots of prognosis about AI (Artificial Intelligence) that, it will take over the world.  At the 18th century, a couple of scientists predicted that within 10 years a digital would be the world’s chess champion. Though it happened at 1996, their predictions didn’t go wrong.  They also predicted that within 3 to 8 years there will be a machine with a general Intelligence of an average human being. British mathematician Alan Turning was one of the first humans who came up with the idea of machines that think in 1950. Turning test, which he had created is still used today, as a benchmark to determine a machine’s ability to think like a human. And after then, in the mid-1950 after Turning died, the term Artificial Intelligence got very well known to people. Elon Musk, The founder of Tesla, Stephen Hawking had described the promising future of AI technology. Today we all know, AI is using at every single sector and every single thing. At this century, AI is taking place in our everyday lives. We are hoping, tomorrow’s world will be replaced by Robot instead of employees in the firms and also in every sector.

Human intelligence:

Human intelligence refers actually functions of our mind which are developed by the capabilities to learn from the past incidents, experiences, lessons from our parents, teachers, friends, and surroundings, accustomedness with new circumstances, approaching towards the intellectual ideas and the ability to turn our own environment using acquired knowledge.

Core Differences between Artificial Intelligence and Human Intelligence:

  • Human intelligence (HI) focuses around accustoming to the environment using its cognitive process where as Artificial intelligence (AI) focuses on outlining machines that can work like human behavior. Human intelligence is the outcome of the natural evolutionary system, but Artificial means which is created by human.
  • Human intelligence is a specimen of the genuine circumstance where as AI is an attempt to model it. And in science, there is a differentiation between the actual circumstance and its equivalent model.
  • HI uses content memory and schema but AI is using the built in, outlining by scientist memory.
  • HI is bigger but AI, as the name suggests, is artificial and temporary. HI is dependable but AI is not, though there are people who debate that human makes more mistakes compared to AI.

Recently in this year, a major development of AI is, a computing system developed by Google has beaten a top human player at the game of GO, the ancient eastern contest. A machine has topped the best human at most games keep up as measures of human intellect, including chess, scrabble, Othello, even in jeopardy! But with go which is a 2500-year-old game, that’s more complicated than chess. Earlier in January of this year, top AI experts outsiders of Google questioned whether the development could happen anytime soon, and many predicted and believed another decade would take before a machine could beat the top humans but Google has proved that this has done. And then the French researcher Remi coulomb agreed and said that it happened faster than I thought.

So, as we can see, what we’re thinking today and predicting about AI, AI proves and solve those complexities faster than our imaginations. So based on the recent illustrations and the differences between Human intelligence and Artificial intelligence, as I have mentioned here in above, I can say, In near future AI have the potentialities that it can beat individual top intelligence human beings based on its own adaptive experiences, studies, and knowledge but when the question comes that whether it can develop its own intelligence by itself then answer will be “NO” which clearly refers its limitations to human intelligence.

Tilova Sumaiya Khan Priyanka is a Business Analyst in Silicon Valley Nest. She has completed her graduation from University of Dhaka. She can be reached at tilova_priyanka@yahoo.com

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Frugality: Saving Resources


Frugality has helped a couple in the United States raise 13 children, own a 7-bedroom house, and 15-passenger van — completely debt free. But some say frugal living demands too many cutbacks on daily expenses, to the point of reducing the quality of life. Others say its benefits go beyond saving. I am of the opinion that frugality is not giving up fun, it is just making careful choices regarding purchases and saying NO to wastage of any kind. In a world where the culture of consumerism is flourishing, choosing a frugal lifestyle can sometimes mean living as an outcast. People may say you’re cheap or tight. My family and I have been living a frugal lifestyle, and we have realized that there are more benefits to frugality than what meets the eye. Frugality doesn’t just benefit people; it benefits our planet too. By making fewer purchases and consuming less, we positively impact the environment in a number of ways. Reusing and recycling old items means less trash in landfills, less energy used for production, packaging, and shipping. And buying a cheap, fuel-efficient used car (or ditching it altogether in favor of a bike or public transportation) helps reduce pollution and greenhouse gases. The bottom line: Being frugal means consuming fewer of the planet’s resources.

The frugal life is always the environmentally friendly life. Nearly every frugal strategy doubles as an environmental boon: driving less, rarely buying new things, not wasting food, using our heat and A/C sparingly – it’s all connected. Frugality is good for humanity too. It means being less wasteful with our already scarce resources. And when we make a commitment to wasting less in general, we’re reducing our carbon footprint and freeing up resources for others who might desperately need them.

Though frugal people are trying hard to make things they do have last longer, they don’t have to spend time shopping around for something new – like spending quality time with family, cultivating a new hobby, or simply relaxing. Frugality isn’t a tactic; it’s a mindset and a joyful lifestyle. Frugality isn’t a sacrifice; it’s a means to an end. Frugality is a positive principle to promote sustainable development.

Let’s look at food wastage. Food waste is a social crime. Food wasted is a food stolen from the hungry stomach. Food wastage is not only the wastage of food per say(disgrace to food too) but also wastage of all energy and other resources which have gone into producing it. I have seen people visiting restaurant and over-ordering which eventually they can’t finish and they leave it as waste. We should start ordering from small quantity and later depending on our appetite, we can order more, also we should not feel shy in getting the left-over packed & brought to home so that we can eat it later rather than wasting it.  The huge amount of food wasted at social gatherings contrasts sharply with the food shortages, often bordering on chronic starvation, faced by millions of poor.In most of the weddings, families are staging extravagant displays of food. The prodigious waste that follows is horrible. About one-fifth of the food served at weddings and social gatherings is discarded. It’s a criminal waste.For example, around 100,000 weddings and social events are held in India every day. Food wasted each day at weddings and family functions in Mumbai (India) alone would be enough to feed the city’s vast slum population.

Food wastage: Key facts and figures

  • The global volume of food wastage is estimated at 1.6 billion tons of “primary product equivalents.” Total food wastage for the edible part of this amounts to 1.3 billion tons.
  • Food wastage’s carbon footprint is estimated about 3.3 billion tons of CO2 equivalent of GHG released into the atmosphere per year.
  • The total amount of water used per year to produce food that is wasted is equivalent to the annual flow of Russia’s Volga River, or three times the volume of Lake Geneva.
  • 4 billion hectares of land – 28 percent of the world’s agricultural area – is used annually to produce food that is lost or wasted.
  • Agriculture is responsible for a majority of threats to at-risk plant and animal species tracked by the International Union for Conservation of Nature.
  • A low percentage of all food wastage is composted: much of it ends up in landfills and represents a large part of the municipal solid waste. Methane emissions from landfills represent one of the largest sources of GHG emissions from the waste sector.
  • Home composting can potentially divert up to 150 kg of food waste per household per year from local collection authorities.
  • Developing countries suffer more food losses during agricultural production, while in middle- and high-income regions, food waste at the retail and consumer level tends to be higher.
  • The direct economic consequences of food wastage (excluding fish and seafood) run to the tune of $750 billion annually.

Arushi Madan is a student of Electronic & Electrical Engineering of University of Birmingham, UK. She is an environmental activist and working on different climate issues and creating awareness to reduce environmental pollution. Besides she has been working as a Regional Ambassador of Tunza Eco- Generation.

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