ANALYSIs TECHNIQUES : Spectroscopies - SHREYA NAIR
INTRODUCTION - Spectroscopies are useful for chemical state analysis (bonding or charge transfer amongst the atoms), electronic structure (energy gaps, impurity levels, band formation and transition probabilities) and other properties of materials.
RAMAN SPECTROSCOPY
PHOTOLUMINESENCE SPECTROMETER
AUGER ELECTRON SPECTROSCOPY
X-Ray and Ultra Violet Photoelectron Spectroscopies (XPS or ESCA and UPS)
REFERENCE
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This presentation include information about electron microscope & types of electron microscope i.e. SEM (Scanning electron microscope) & TEM (Transmission electron microscope).
An electron microscope is a microscope that uses a beam of scattered electrons as a source of illumination. It is used to get information about structure, topology, morphology & composition of materials. It has many advantages. Basically there are 4 types of electron microscope but here we will discuss only 2 types.
Transmission electron microscopy is a microscopy technique in which a beam of electrons is transmitted through an ultra-thin specimen, interacting with the specimen as it passes through it. Its resolution & magnification is about 10,000,000x. There are 5 types of transmission electron microscope i.e. BFTEM (Bright field transmision electron microscope), DFTEM (Dark field transmission electron microscope), HRTEM (High resolution transmission electron microscope), EFTEM (Energy filtered transmission electron microscope), ED (Electron diffraction). there are 4 techniques of TEM i.e. negative staining, shadow casting, Freeze fracture replication, freeze etching. It has many applications e.g, for the study of Cancer research, virology, chemical industry, electronic structure etc.
A scanning electron microscope is a type of electron microscope that produces images of a sample by scanning it with a focused beam of electrons. Types of signals produce by SEM include secondary electrons, back scattered electrons, X-rays, light rays. There are many advantages of SEM e.g, Btter resolution, fast imaging easy to operate, work with low voltage etc.
Its a theoretical content for Pharmacy graduates, post graduates in pharmacy and Doctor of Pharmacy And also M Sc Instrumentation, UG and PG of Ayurveda medical students, MS etc.
It includes topics regarding the Electron and ion spectroscopy. It consist of results of minute research done on the topics like electron spectroscopy for chemical analysis, auger spectroscopy, secondary ion mass spectroscopy, surface spectroscopic techniques and is very helpful for the analysis and presentation point of view.
This presentation include information about electron microscope & types of electron microscope i.e. SEM (Scanning electron microscope) & TEM (Transmission electron microscope).
An electron microscope is a microscope that uses a beam of scattered electrons as a source of illumination. It is used to get information about structure, topology, morphology & composition of materials. It has many advantages. Basically there are 4 types of electron microscope but here we will discuss only 2 types.
Transmission electron microscopy is a microscopy technique in which a beam of electrons is transmitted through an ultra-thin specimen, interacting with the specimen as it passes through it. Its resolution & magnification is about 10,000,000x. There are 5 types of transmission electron microscope i.e. BFTEM (Bright field transmision electron microscope), DFTEM (Dark field transmission electron microscope), HRTEM (High resolution transmission electron microscope), EFTEM (Energy filtered transmission electron microscope), ED (Electron diffraction). there are 4 techniques of TEM i.e. negative staining, shadow casting, Freeze fracture replication, freeze etching. It has many applications e.g, for the study of Cancer research, virology, chemical industry, electronic structure etc.
A scanning electron microscope is a type of electron microscope that produces images of a sample by scanning it with a focused beam of electrons. Types of signals produce by SEM include secondary electrons, back scattered electrons, X-rays, light rays. There are many advantages of SEM e.g, Btter resolution, fast imaging easy to operate, work with low voltage etc.
Its a theoretical content for Pharmacy graduates, post graduates in pharmacy and Doctor of Pharmacy And also M Sc Instrumentation, UG and PG of Ayurveda medical students, MS etc.
It includes topics regarding the Electron and ion spectroscopy. It consist of results of minute research done on the topics like electron spectroscopy for chemical analysis, auger spectroscopy, secondary ion mass spectroscopy, surface spectroscopic techniques and is very helpful for the analysis and presentation point of view.
Spectroscopy techniques, it's principle, types and applications NizadSultana
Spectroscopy and it's applications as well as it's types like Infrared spectroscopy and ultraviolet spectroscopy and principle of spectroscopy why we use spectroscopy.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
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.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
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.
The increased availability of biomedical data, particularly in the public domain, offers the opportunity to better understand human health and to develop effective therapeutics for a wide range of unmet medical needs. However, data scientists remain stymied by the fact that data remain hard to find and to productively reuse because data and their metadata i) are wholly inaccessible, ii) are in non-standard or incompatible representations, iii) do not conform to community standards, and iv) have unclear or highly restricted terms and conditions that preclude legitimate reuse. These limitations require a rethink on data can be made machine and AI-ready - the key motivation behind the FAIR Guiding Principles. Concurrently, while recent efforts have explored the use of deep learning to fuse disparate data into predictive models for a wide range of biomedical applications, these models often fail even when the correct answer is already known, and fail to explain individual predictions in terms that data scientists can appreciate. These limitations suggest that new methods to produce practical artificial intelligence are still needed.
In this talk, I will discuss our work in (1) building an integrative knowledge infrastructure to prepare FAIR and "AI-ready" data and services along with (2) neurosymbolic AI methods to improve the quality of predictions and to generate plausible explanations. Attention is given to standards, platforms, and methods to wrangle knowledge into simple, but effective semantic and latent representations, and to make these available into standards-compliant and discoverable interfaces that can be used in model building, validation, and explanation. Our work, and those of others in the field, creates a baseline for building trustworthy and easy to deploy AI models in biomedicine.
Bio
Dr. Michel Dumontier is the Distinguished Professor of Data Science at Maastricht University, founder and executive director of the Institute of Data Science, and co-founder of the FAIR (Findable, Accessible, Interoperable and Reusable) data principles. His research explores socio-technological approaches for responsible discovery science, which includes collaborative multi-modal knowledge graphs, privacy-preserving distributed data mining, and AI methods for drug discovery and personalized medicine. His work is supported through the Dutch National Research Agenda, the Netherlands Organisation for Scientific Research, Horizon Europe, the European Open Science Cloud, the US National Institutes of Health, and a Marie-Curie Innovative Training Network. He is the editor-in-chief for the journal Data Science and is internationally recognized for his contributions in bioinformatics, biomedical informatics, and semantic technologies including ontologies and linked data.
2. INTRODUCTION
• Nanomaterials, dispersed in the form of colloids in solutions, particles (dry powders)or thin
films, are characterized by various techniques.
• Although the techniques to be used would depend upon the type of material and information
one needs to know, usually one is interested in first knowing the size, crystalline type,
composition, thermal, chemical state, and properties like optical or magnetic properties.
• Spectroscopies are useful for chemical state analysis (bonding or charge transfer amongst the
atoms), electronic structure (energy gaps, impurity levels, band formation and transition
probabilities) and other properties of materials.
3. RAMAN SPECTROSCOPY
• Raman spectroscopy is another powerful technique for the analysis of molecules or particles.
• Raman active molecules depend upon the polarizability of the molecule.
• The technique is based on the Raman effect discovered by Sir C.V. Raman in 1928.
• Whenever scattering of the light occurs, the scattered light consists of two types viz. Rayleigh scattering and
Raman Scattering.
• Rayleigh scattering is strong and has the same frequency (elastic scattering) as the incident beam (V0), and the
other is called Raman scattering.
• Raman scattering is inelastic scattering .
• Raman scattering is very weak (10-5 of the incident beam).
4. • The decreased frequency and increased frequency lines are called the Stokes and anti-Stokes lines, respectively.
• The scattering is described as an excitation of the molecule to a virtual state which is lower in energy than a real
electronic transition, with nearly coincident de-excitation and a change in vibrational energy.
• A Raman spectrometer comprises four components which are: (1) excitation source (laser), (2) sample illumination
and collection system, (3) wavelength selector and (4) detector and computer processing system.
• FT-Raman spectrometer is preferred.
• The instrumentation of FT Raman is similar to normal Raman spectrometer with an additional inclusion of a
Michelson interferometer, which enables the simultaneous acquisition of signals of all frequencies along with the
improved resolution.
• The instrumentation of FT Raman is similar to normal Raman spectrometer with an additional inclusion of a
Michelson interferometer, which enables the simultaneous acquisition of signals of all frequencies along with the
improved resolution.
5. • The laser is incident on the sample by means of a lens and a parabolic mirror. The scattered light from the sample is
collected and passed to a beam splitter and to the moving and fixed mirrors in the interferometer head. It is then
passed through a series of filters and focused onto a liquid-nitrogen cooled detector.
• Raman spectra are shown as ‘Raman shift’.
• Raman spectra are considered to be indispensable for carbon nanotubes and other carboneous materials as
amorphous, crystalline etc. characteristic forms can be easily identified.
6. PHOTOLUMINESENCE
SPECTROMETER
• Some materials when excited with an
external source of stimulus like electrons
or light emit light in the visible range, UV
or IR. This phenomenon is known as
luminescence.
• Many nanomaterials exhibit enhanced
(increased intensity) luminescence as
compared to their bulk counterparts. Some
materials like silicon which are not
luminescent in their bulk form become
luminescent in nano form, like porous
silicon.
7. • A source of photons ranging from UV (200 nm) to IR (800 nm), a filter to
throw away large band of wavelengths, wavelength selectors or
monochromators, sample holder, a detector and a recording system like an X-
Y recorder or a computer.
AUGER ELECTRON SPECTROSCOPY
• When one of the electrons from a core level is removed, an electron from
outer level combines with the core hole. The energy difference between
the two levels is either emitted as X-ray (photons) or utilized in emitting
an electron from one of the outer levels. An electron removed by the later
process is known as Auger electron.
8. EXPERIMENTAL
SETUP
• AlK’α with photon energy 1,486.6 eV and MgK’ α
with photon energy 1,253.6 eV are available from a
twin anode as source of X-rays.
• Auger electrons can be a part of photoelectron
spectrum. However, it is common to use an electron
gun (2–5 keV) as the source of incident electrons to
create core holes. Electrons have the advantage that
they can be generated easily and focused to a small
spot. They also can be rastered on the sample
surface.
9. • Photoelectrons and Auger electrons are analyzed in the same analyzer using Concentric Hemispherical Analyzer
(CHA) or double pass Cylindrical Mirror Analyzer (CMA). Analyzer is controlled using spectrometer control unit
(SCU).
• Electrons passing through them are selected according to their energies, are detected and amplified using
channeltron or channel plate. Amplified signal is an input for an X-Y recorder or a computer
X-Ray and Ultra Violet Photoelectron Spectroscopies (XPS or
ESCA and UPS)
• Photon of fixed energy hν incident on an atom ejects an electron of binding energy EB with kinetic energy EK
according to the equation :
hν = EK + EB
10. Ingredients of X-Ray
Photoelectron Spectra
• When an electron is ejected from a solid sample, a hole is
created. Binding energy measured, therefore, gives the energy
of the photoelectron in presence of the hole.
• When an electron leaves an atom, remaining electrons of the
atom (and even the surrounding atoms) interact with the hole.
• Chemical shift – Core electrons of atoms in solids are very
sensitive to their surrounding. Whenever there is a charge
transfer between outer electrons of different atoms, core
electrons also respond to these changes by changing their
energies. Thus, there are changes in the binding energies of
electrons in a solid. These changes can be studied by analyzing
the kinetic energies of photoelectrons.
11. • Auger peaks – Along with photoelectron peaks, some Auger peaks characteristics of elements present in the solid
also can be obtained in a spectrum.
• Spin-orbit splitting – Some of the peaks in photoelectron spectra appear as doublets. Spin-orbit splitting for a
given atom decreases with increase in the principal quantum number. It increases for a given principal quantum
number with increase in atomic number.
• Multiplet splitting – Large magnetic moments on some of the atoms/ions arise due to unpaired electrons in their
3d, 4d or 4f shells. Photoelectron spectroscopy can be used to detect the presence of such unpaired electrons.