Friday, January 28, 2011

Nepal Chemical Society organizing a national workshop on scientific writing


We have received email from Prof Raja Ram Pradhananga, President of Nepal Chemical Society about the workshop.


Dear Colleagues,
On behalf of the Nepal Chemical Society, I am pleased to inform you that Nepal Chemical Society is going to organize a National workshop on scientific writing on February 11-12, 2011 in Kathmandu.

The workshop aims to introduce the art of scientific writing from prominent scientists of Nepal. The emphasis will be given on three main areas of the scientific writings.

1.  How to write an acceptable scientific paper for the publication in national or international journal.
2.  How to write a research proposal for grants from national and international organization.
3.  How to write an initial research proposal for Ph.D. registration.


I take this opportunity to invite you to participate in this workshop for details. Please refer to the brochure on National workshop on scientific writing.


With best regards,
Prof. Dr. Raja Ram Pradhananga
Convener
National Workshop on Scientific writing
Nepal Chemical Society
www.ncs.org.np
nworkshop2011@ncs.org.np

Thursday, January 27, 2011

Supramolecule: Leader of the Nano-world

Anant Babu Marahatta
Ph.D. student in Chemistry
Tohoku University
Japan


Tailoring “Molecular machine” on the atomic or molecular scale is the current subject of interest in the nano-world. In order to explore the molecular architectures behind it, the first and the foremost motivation came by mimicking the biological systems such as enzymes/catalysts/promoters along with some mechanical devices which leads to supramolecules.


The literal meaning of the supramolecule is “beyond the molecule” and the area of chemistry which mainly concentrates on such system is Supramolecular chemistry. It refers to that sort of molecular system which is made up of a distinct number [more than one] of molecular assemblies. Terms such as molecular self-assembly (1D, 2D & 3D), molecular hierarchy, molecular machine, host-guest chemistry, nanoscience are often associated with this area.

The consideration of the intermolecular [between molecules] interactions and the chemistry involved into it, rather than intramolecular [within molecule], is the major objective of the supramolecular chemistry. In this area, molecule acts as a building block unlike in traditional molecular chemistry [where atom acts as a building block]. In molecular chemistry, the binding forces between the atoms are covalent and ionic. In contrast, the non-covalent interactions such as hydrogen-bonding, dipole-dipole and dipole-quadrupole interactions, van der Waal forces and hydrophilic-hydrophobic interaction are the binding forces which hold the supramolecular assembly together. The following video highlights the procedure of molecules clustering in nanometer range.


The origination of the concept of the molecular machine is also fascinated by the molecular network of the supramolecules as well as their systematic arrays. The molecular rotors, molecular brakes, molecular gears, quantum gyroscopes, molecular ratchets etc. are the recently originated ideas. Some of their practical approaches have already been implemented. 
One of the great achievements of the molecular machine is to find the intercellular viscosity which provides the strongest supporting evidence during medical diagnosis. Similarly, “Quantum gyroscope could reveal Universe’s spin” is another recent attractive scientific finding.


If one could able to control the molecular networks of the supramolecules, their pattern and their chemistry externally either by using some electric/magnetic/photonic stimuli or by adsorbing them one or multi dimensionally at some rigid surface and functionalize, this would be the great boon to the nanoworld. Can we? “Yes we can”.





NepaChem would like to see you all as a “driver” of the novel supramolecules.

References:

J.AM.CHEM.SOC. 2008,130, 6672-6673
PhysRevLett.2004, 93,137403 (1-4)
http://www.newscientist.com/article/dn2526
http://en.wikipedia.org/wiki/File:Cucurbituril_gyroscope_AngewChemIntEd_2002_v41_p275_hires.png

Tuesday, January 25, 2011

NepaChem listed in Nature blogs

It is our pleasure to share with you that our blog NepaChem is listed in Nature.com blogs. Please click this link to see lots of blogs listed. Nature blog lists variety of science related blogs in its blog list after reviewing the content and other features of the blog by multiple community moderators. Moderators look for a combination of different factors. Their guidelines suggest that for a blog to be accepted it should be:
  1. Composed mostly of original material-no press releases or lists of links
  2. Primarily concerned with scientific research
  3. Updated (on average) at least once a fortnight.
We are glad that NepaChem passed all these criteria.
Thank you for your support.

Thursday, January 20, 2011

“Top Down” and “Bottom Up” approaches in chemistry

Anant Babu Marahatta
Ph.D. student in Chemistry
Tohoku University
Japan
Who are chemists? Most of you definitely agree with me if I said “Chemists are scientists trained in the field of Chemistry and describe the properties of the matter on the level of molecules and their component atoms.” But if I said “Chemists are ‘tailor’ who make the world fashionable by implementing “top down” and “bottom up” approaches” in chemistry, most of you get confused.


Even though “Top down” and “Bottom up” approaches of chemistry were first applied to the field of nanotechnology in 1989, these terms are not so much familiar among the chemists like us. Thus this article is intended to describe the principles and the perspectives of these approaches which have grown exponentially in the last few decades.



To describe the “top down” approach, let us consider a macroscopic system and break down into the several subsystems and then start analyzing these subsystems and refine them in greater detail until the entire composition is reduced to their base elements. It can be clarified by saying that “top down” is the destructive approach to go insight into the fundamental level [going top to down] and adapt their features to make them functional at a smaller scale. Though it is a traditional way, Chemists sometimes consider the hypothesis which starts at the top with the most general concepts and works down through less general concepts to the most specific details.


On the other hand, the “bottom up” technique is based on the principle of starting from the fundamental [bottom] parts and assembled [going up] them to obtain the desired more complex system [going bottom to up]. Thus, it is the constructive approach to stitch the fundamental parts together and develop the new inventions.



In chemistry, the “bottom up” approach makes the use of atomic/molecular components and assembled them to develop the potential nano-devices. This approach is already implemented even for interconnecting the multiwalled carbon nanotubes into the multilevel interconnects (silicon integrated-circuit) with higher current conducting capacity.

To conclude, both “top down” and “bottom up” approaches in chemistry have their contribution to the development of nanotechnology but as far as the future is concerned the “bottom up” is a promising technique for the most effective and smart molecular architectures.

NepaChem would like to see you all as a “stylist of the nano-world” in the near future.

Thursday, January 13, 2011

Macroscopic and Microscopic [molecular] Gyroscopes

Anant Babu Marahatta
Ph.D. student in Chemistry
Tohoku University, Japan



Fabricating the nano devices on an atomic and molecular scale (referred as Molecular machine) is the major aspect of the Nanotechnology (sometimes shortened to “nanotech”). One of the recent approaches of the nanotech is “molecular self-assembly” which is governed by the concept “can we directly control matter on the atomic scale?” By considering this sort of challenging prospect, several gyroscopes [as shown in fig.] like molecules have been designing / synthesizing.
















The similarities between the macroscopic gyroscope and the molecular gyroscope are solely based on their mechanical parts assembled. The macroscopic gyroscope which is used in aircrafts, ships to route them, contain the mechanical parts like spinning axis-axle, rotating part-rotor and the static framework-stator [gimbal] to uphold the rotor by conserving angular momentum.


Just like this, the molecular gyroscope also possesses the similar fundamental mechanical parts which are labeled in the figure. The rotational dynamics of the rotator enclosed into the case of the stator is controlled by the chemistry of the later. The animated view is included herewith.



As the molecular gyroscope is composed of an infinite network [infinite “gyroscope like molecules”] unlike its macroscopic analogue, the dynamics of it must rely on their order and collective behavior in their crystalline state. So, in terms of getting collective output of this network, several challenges must be faced.

Friday, January 7, 2011

Molecular Motors/Rotors/Brakes and Gyroscopes [Learn by fun!!!]

Anant Babu Marahatta
PhD student in chemistry
Tohoku University, Japan

One of the current aspects of chemistry is being a watch-dog of the nanoworld. I wonder how many of you are familiar with the microscopic machinery terms used in Chemistry that concentrates especially in the designation of the Molecular Machine. Some of them are Molecular motors, Molecular Rotors, Molecular Brakes, and Molecular Gyroscopes. You may find several of them by consulting the literatures/text books published so far.

I am sure that all of you [for the beginners only] are familiar with the “molecules” and the macroscopic devices such as Motors or Rotors or Brakes or Gyroscopes. But I think, very few of us [including chemists] have got the concrete knowledge about their applications in the nanoworld or in the Molecular machinery. We, the members of “Nepa Chem”, will assure our fellows/readers that the detail explanation with the proper schematic illustrations of all the mentioned molecular machinery devices will be posted in the days to come. For now, let me define them very shortly.



Molecular motors, Molecular Rotors, Molecular Brakes, and Molecular Gyroscopes, all these names are derived from their macroscopic analogues. Synthetic/computational chemists have already synthesized/designed the molecules or supra molecules which resembled mechanically to these macroscopic devices. Thus in this stage, you readers are about to catch the main point. I am sure that you all are thinking like this way; if the synthesized molecules/supra molecules resembled mechanically to that of the macroscopic rotating devices, then these molecules are called Molecular rotors. If the synthesized molecules/supra molecules resembled to that of the macroscopic motors [which contain rotors too, complexity arises], then these molecules are called Molecular motors.

The macroscopic Gyroscopes which are used in aircrafts, ships to route them, contain the mechanical parts like rotating axis-axle, rotating part- rotor and the static framework-stator to uphold the rotor by conserving angular momentum. Hurray!!!!The meaning of the molecular Gyroscope is also clarified!!! Do you agree? If not, your level of understanding is not the worst!!!! …lol….The molecules/supra molecules resembled to those of the Macroscopic Gyroscopes mechanically are called Molecular Gyroscopes. You must be very happy!!!!! Aren’t you? Because whatever you were thinking is correct!!!!

The case of the molecular brake is different. You can imagine yourself!!!! Can you? Do you have driving license? Do you brake [be careful, not break, funny writer, isn’t it?] your car?  If not, come here in Japan, I rent a TOYOTA car. Anyway, a “Brake” is a device for slowing or stopping the motion. Wow! So sad!!! There must be some parts in motion before applying brake, unlike in rotors/motors and gyroscopes. Thus the challenging part for the computational chemists/synthetic chemists is that the same molecule must possess dynamic parts as well as brake. According to my experience, some atoms of the molecules, during the rapid motion of the dynamic parts, migrate towards the active site of the same molecule and the motion of the dynamic parts stopped / braked. However, the automatic migration of the atoms which act as a brake is rare. Some of the external sources [electric field, magnetic field, optical field etc.] that initiate this migrating mechanism must be intruded. So far, laser is one of the predominant sources. Similarly, changing the structure after receiving the impulse is also common braking phenomenon. Here is an example of the molecular brake, thousands of times smaller than the width of a human hair, developed by the researchers in Taiwan. It is powered by light and is the first capable of working at room temperature. The animated view of the schematic illustration of the light-driven molecular brake is posted above!!! Enjoy!!!!!

This molecular brake resembles a tiny four-bladed wheel (a rigid pentiptycene group shown in blue in the illustration above) and contains light-sensitive molecules. The paddle-like structure spins freely when a nanomachine is in motion. Exposing the structure to light changes its shape so that the blades stop spinning, 'the braking effect is on'. The braking power can be turned off and on by altering the wavelength of light exposure.

I hope that you readers are able to get the fundamental concepts about these molecular machines. If you are synthetic /computational chemists, I am sure that you will immediately start designing such molecules and contribute into the nano-world. 

Good luck from my/Nepa Chem side!!!!!

Sunday, January 2, 2011

DEATH BY POTASSIUM PERMANGANATE [KMnO4]

KMnO4 Solution
ANANT BABU MARAHATTA
Ph.D. student
Tohoku University, Japan

Potassium permanganate is not a new chemical for the chemists as well as for other scientists. It is generally used in even very simple lab. It is a crystalline, colored substance and soluble in water. Its salts are normally stable in crystalline form but Zinc permanganate can become explosive. In fact, storing it in tightly stopper bottles is highly dangerous. The color of the solution of KMnO4 is differed depending upon its concentration. If the concentration is about one part per million (1 PPm), the solution has a faint pink color. When the concentration is one part in 76000 (65mg/4.5dm3), the fluid becomes purple. Because of its color, solution has been used for staining purpose too. Those who use the chemical as a stain for flooring and woodwork and work with the concentrated solution must exercise with great care.


Infection due to KMnO4
We never believed potassium permanganate could be a poison too. In fact it is used to treat certain poisoning; such as poisoning by Opium (a drug), KMnO4 solution indeed is recommended. Doctors actually wash the stomach of patient [Opium user] with this solution because KMnO4 oxidizes the Opium. Similarly in many other poisonings, doctors wash the stomach with KMnO4 solution. But unfortunately permanganate acts as a poison too. In fact about 10-20gm of KMnO4 is enough to kill the person.

KMnO4 is a very common substance and it can be acquired without any restriction by the public. Yet poisoning by it is uncommon but doctors are probably facing a death due to this substance; in fact fatal poisoning by KMnO4 is rare. But children in particular must be protected against the ingestion of the colored crystals which they may mistake for sweets. The child aged about 22 months was died after eating some permanganate crystals which his father used for gardening. Tablets of KMnO4 are still on sale in the USA.

KMnO4 is an irritant substance. It irritates the uterus too and may cause it to expel its contents. This has made the use of KMnO4 very popular in illegal abortions. Some women simply ingest it while some make its solution and introduce it in their uterus through the vaginal route. Some women simply introduce the crystals of KMnO4 in their vagina.The insertion of tablets of KMnO4 into the vagina to procure abortion first came to notice in Spain and Italy during 1930s.Although the abortion has become legal in most of the counties, this practice has not yet been abandoned. The reason is that most unmarried girls for fear of society’s censure still do not want to disclose that they have become pregnant. They prefer to go for abortions by these dangerous methods. This has caused several deaths too.

Women make a solution of KMnO4 and then with the help of appropriate instrument, push this solution into their uterus. This process is called “DOUCHING”, which is also very common. The douching may be done to procure an abortion or only for hygienic reasons as KMnO4 is supposed to be an antiseptic. If, however, solution is too concentrated it can have dangerous and probably fatal consequences. As the doctor used KMnO4 for stomach wash in certain poisonings, but the question arises that doesn’t it kill the patient? The answer is that when KMnO4 is used for stomach wash, it is used in a solution of strength 1:5000.It only acts as an irritant at higher concentration of about 1:1000.

KMnO4 can be easily dissolved in red wine and the colors of both are almost similar. Moreover the taste of red wine would mask the taste of KMnO4. So the person would get accidentally poisoned by having some drinks contaminated with KMnO4. KMnO4 has not been really used for homicide. It has more often been used for suicidal purposes, but accidental poisoning also occurs, notably in children under the age of four years, who usually mistake the red colored crystals for sweets. Even adults have been known to take the poison mistakenly.

Another popular although wrong belief is that it is a remedy for amenorrhoea,
[A girl generally starts menstruating at about the age of 13 years, but if the menstruation cycle does not start, the condition is known as amenorrhoea]. Ideally when faced with such a symptom, a woman should contact a doctor but many women prefer to treat themselves by folk remedies, and KMnO4 is one of the folk remedies for amenorrhoea. This is done by taking pills containing 65-130mg of KMnO4 before the expected period of menstruation.

What are the symptoms appeared after ingesting KMnO4?

The person suddenly develops a burning pain in his abdomen with nausea and vomiting. The vomited material contains some brown pigments. He complains of intense thirst too. Staining of tissues is very obvious. Some patient may have brown stains on the face in linear form running down from an angle of the mouth. The eyes and the face will be stained if crystals fall onto the face. The interior part of the mouth of the patient usually decolorized [after poisoning, the color is purple-brown but within few minutes this changes brown or dark- brown and later following the formation of MnO2 which gives coal black color]. The presence of coal black at the inner part of food pipe is the clear symptom for the patient. The corrosion of stomach and food pipe will take place due to the formation of potassium hydroxide formed by the action of KMnO4 on tissues. The lips, gums, teeth, tongue, tonsils, pharynx and the upper end of the larynx are all likely to be discolored, inflamed and superficially corroded. These may severe at points where any crystals may lodge inside the mouth, throat, and lips inside the cheeks or within the piriform fossae [pear shaped pockets on either side of the pharynx]. If the crystals of the KMnO4 get lodged in piriform fossae, they can corrode these areas. Then the patients experience difficulty in speaking as well as in swallowing. The stools seem black due to the manganous sulphide compound. Irritation of the trachea and bronchi leads to difficulty in respiration. A lethal dose, about 20g kills the person with in 20 to 90 hours. But when KMnO4 is introduced into the uterus, death may occur with in 12 hours.

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