more chemistry contents are available
1. pdf file on Termmate: https://www.termmate.com/rabia.aziz
2. YouTube: https://www.youtube.com/channel/UCKxWnNdskGHnZFS0h1QRTEA
3. Facebook: https://web.facebook.com/Chemist.Rabia.Aziz/
4. Blogger: https://chemistry-academy.blogspot.com/
BS-III
more chemistry contents are available
1. pdf file on Termmate: https://www.termmate.com/rabia.aziz
2. YouTube: https://www.youtube.com/channel/UCKxWnNdskGHnZFS0h1QRTEA
3. Facebook: https://web.facebook.com/Chemist.Rabia.Aziz/
4. Blogger: https://chemistry-academy.blogspot.com/
BS-III
Boson: A Singnificant Sub-Atomic Particle pptxLalitKishore18
The presentation is meant for senior physics students since the chapter of particle physics has been added at A level or senior secondary physics course
Nuclear physithese slides are related to the introduction of nuclear physics some contents is given which are related to the discovery of nucleus. The history of atoms etc
21) What are the fundamental particles of lepton and quarks How man.pdfpetercoiffeur18
21) What are the fundamental particles of lepton and quarks? How many are known thus far?
Solution
Quarks are one type of matter particle. Most of the matter we see around us is made from protons
and neutrons, which are composed of quarks.
There are six quarks, but physicists usually talk about them in terms of three pairs: up/down,
charm/strange, and top/bottom.(Also, for each of these quarks, there is a corresponding
antiquark.)
Quarks have the unusual characteristic of having a fractional electric charge, unlike the proton
and electron, which have integer charges of +1 and -1 respectively. Quarks also carry another
type of charge called color charge.
The most elusive quark, the top quark, was discovered in 1995 after its existence had been
theorized for 20 years.
Quarks only exist in groups with other quarks and are never found alone. Composite particles
made of quarks are called Hadron.
Although individual quarks have fractional electrical charges, they combine such that hadrons
have a net integer electric charge. Another property of hadrons is that they have no net color
charge even though the quarks themselves carry color charge.
There are two classes of hadrons:-
Baryon: - they are any hadron which is made of three quarks. Because they are made of two up
quarks and one down quark (uud), protons are baryons. So are neutrons (udd).
Meson: - it contains one quark and one anti quark. One example of a meson is a pion which is
made of an up quark and a down anti quark. The antiparticle of a meson just has its quark and
antiquark switched, so an anti pion is made of a down quark and an up antiquark.
Because a meson consists of a particle and an antiparticle, it is very unstable. The K meson lives
much longer than most mesons, which is why it was called \"strange\" and gave this name to the
strange quark, one of its components.
Leptons
The other type of matter particles are the leptons.
There are six leptons, three of which have electrical charge and three of which do not. They
appear to be point-like particles without internal structure. The best known lepton is the electron.
The other two charged leptons are the muon and the tau which are charged like electrons but
have a lot more mass. The other leptons are the three types of neutrinos. They have no electrical
charge, very little mass, and they are very hard to find.
Quarks are one type of matter particle. Most of the matter we see around us is made from
protons and neutrons, which are composed of quarks..
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Comparative structure of adrenal gland in vertebrates
Elementary particles
1. ELEMENTARY PARTICLES and their
classification
Mrs.P.Kanmani, M.Sc.,M.Phil,
Assistant Professor of Physics
2. What are Elementary Particles?
• An elementary particle or fundamental particle is a particle
that does not have a substructure.
• It is not known to be made up of smaller particles.
• Particles that have no substructure could be considered the
basic building blocks of the universe from which all other
particles are made.
3. History of Elementary of particles
• The first subatomic particle to be discovered was the electron,
identified in 1897 by J. J. Thomson.
• The nucleus of the atom was discovered in 1911 by Ernest
Rutherford, the nucleus of ordinary hydrogen was recognized
to be a single proton. In 1932 the neutron was discovered.
• An atom was seen to consist of a central nucleus—containing
protons and, except for ordinary hydrogen, neutrons—
surrounded by orbiting electrons.
• Historically they were once regarded as fundamental
constituents of every matter.
4. History of Elementary of particles
• In 1928 the relativistic quantum theory of P. A. M. Dirac
hypothesized the existence of a positively charged electron, or
positron, which is the antiparticle of the electron; it was first
detected in 1932.
• Difficulties in explaining beta decay led to the prediction of
the neutrino in 1930, and by 1934 the existence of the
neutrino was firmly established in theory (although it was not
actually detected until 1956).
• Photon was suggested by Einstein in 1905 as part of his
quantum theory of the photoelectric effect .
5. History of Elementary of particles
• In 1935 Hideki Yukawa suggested that a meson (a charged
particle with a mass intermediate between those of the
electron and the proton) might be exchanged between
nucleons.
• The meson emitted by one nucleon would be absorbed by
another nucleon; this would produce a strong force between
the nucleons, analogous to the force produced by the
exchange of photons between charged particles interacting
through the electromagnetic force.
6. History of Elementary of particles
• In 1947 the particle predicted by Yukawa was discovered and
named the pi meson, or pion which was 200 times heavier
than electron .
• Both the muon and the pion were first observed in cosmic
rays .
• Further studies of cosmic rays turned up more particles.
• Each elementary particle is associated with
an antiparticle with the same mass and opposite charge.
7. History of Elementary of particles
• Some particles, such as the photon, are identical to their
antiparticle.
• Such particles must be neutral, but not all neutral particles are
identical to their antiparticle.
• By the 1950s these elementary particles were observed in the
laboratory as a result of particle collisions produced by
a particle accelerator .
8. Classification of Elementary Particles
• The fundamental particles may be classified into groups in
several ways.
• First, all particles are classified into fermions, which obey
Fermi-Dirac statistics and bosons, which obey Bose-Einstein
statistics.
• Fermions have half-integer spin, while bosons have integer
spin.
9. Classification of Elementary Particles
• All the fundamental fermions have spin 1/2. Electrons and
nucleons are fermions with spin 1/2.
• The fundamental bosons have mostly spin 1. This includes the
photon.
• The pion has spin 0, while the graviton has spin 2. There are
also three particles, the W+, W− and Z0 bosons, which are
spin 1. They are the carriers of the weak interactions.
11. Classification of Elementary Particles
• The electron and the neutrino are members of a family
of leptons.
• The leptons are distinguished from other particles called
hadrons in that leptons do not participate in strong
interactions.
12. Classification of Elementary Particles
• Hadrons are strongly interacting particles. They are divided
into baryons and mesons.
• The baryons are a class of fermions, including the proton and
neutron, and other particles which in a decay always produce
another baryon, and ultimately a proton.
• The mesons are bosons.
13. Classification of Elementary Particles
• Protons and neutrons are made of still smaller particles
called quarks.
• It appears that the two basic constituents of matter are the
leptons and the quarks.
• There are believed to be six types of each. Each quark type is
called a flavor, there are six quark flavors.
• Each type of lepton and quark also has a
corresponding antiparticle, a particle that has the same mass
but opposite electrical charge and magnetic moment.
14. Classification of Elementary Particles
• In the current theory, known as the Standard Model there are
12 fundamental matter particle types and their corresponding
antiparticles.
•
15. Classification of Elementary Particles
• In addition, there are gluons, photons, and W and Z bosons,
the force carrier particles that are responsible for strong,
electromagnetic, and weak interactions respectively. These
force carriers are also fundamental particles.
•