For analytical students
Differential thermal analysis is a technique through which we can measure the change in temperature as a function of time or temperature
you can surely get concept of this technique along with the applications of this technique
In this slides contains principle and instrumentation of Differential Scanning Calorimeter (DSC).
Presented by: N Poojitha. (Department of pharmaceutics),
RIPER, anantapur.
Slide covers three methods of thermal analysis i.e., thermogravimetry, differential thermal analysis, and differential scanning calorimetry. Thermal analysis methods are well-established techniques in research laboratories of pharmaceutical industry. Thermal analysis includes all methods measuring some parameter during the heating of a sample .Thermal analysis is widely used to study the thermal stability, char content, and decomposition temperature of polymer composites reinforced with natural/synthetic fibers/or nanosized fillers etc.
Differential Thermal Analysis (DTA),principle of DTA, working of DTA, instrumentation of DTA, thermogram factors affecting DTA curve, advantages and disadvantages, applications of DTA, Thermogravimetry (TG),types of TG, principle of TG, working of TG, instrumentation of TG, thermogram of TG, factors affecting TG curve, advantages and disadvantages, applications of TG
In thermogravimetric analysis, the change in weight in
relation to a change in temperature in a controlled environment is measured. Heat is used in TGA to force
reactions and physical changes in materials. Thermogravimetric analysis (TGA) is a reliable method to determine
endotherms, exotherms, measure oxidation processes, thermal stability, decomposition points of explosives,
characteristics of polymers, solvent residues, the level of organic and inorganic components of a mixture,
degradation temperatures of a material, and the absorbed moisture content of materials. Materials analyzed by
thermogravimetric analysis include explosives, petroleum, chemicals, biological samples, polymers, composites,
plastics, adhesives, coatings, organic materials, and pharmaceuticals.The thermogravimetric analysis instrument usually consists of a high-precision balance and sample pan.
The pan holds the sample
material and is located in a
furnace or oven that is
heated or cooled during the
experiment. A thermocouple
is used to accurately control
and measure the
temperature within the oven.
The mass of the sample is
constantly monitored during
the analysis. An inert or
reactive gas may be used to
purge and control the
environment. The analysis is
performed by gradually
raising the temperature and plotting the
substances weight against temperature. A
computer is utilized to control the
instrument and to process the output
curves.
In this slides contains principle and instrumentation of Differential Scanning Calorimeter (DSC).
Presented by: N Poojitha. (Department of pharmaceutics),
RIPER, anantapur.
Slide covers three methods of thermal analysis i.e., thermogravimetry, differential thermal analysis, and differential scanning calorimetry. Thermal analysis methods are well-established techniques in research laboratories of pharmaceutical industry. Thermal analysis includes all methods measuring some parameter during the heating of a sample .Thermal analysis is widely used to study the thermal stability, char content, and decomposition temperature of polymer composites reinforced with natural/synthetic fibers/or nanosized fillers etc.
Differential Thermal Analysis (DTA),principle of DTA, working of DTA, instrumentation of DTA, thermogram factors affecting DTA curve, advantages and disadvantages, applications of DTA, Thermogravimetry (TG),types of TG, principle of TG, working of TG, instrumentation of TG, thermogram of TG, factors affecting TG curve, advantages and disadvantages, applications of TG
In thermogravimetric analysis, the change in weight in
relation to a change in temperature in a controlled environment is measured. Heat is used in TGA to force
reactions and physical changes in materials. Thermogravimetric analysis (TGA) is a reliable method to determine
endotherms, exotherms, measure oxidation processes, thermal stability, decomposition points of explosives,
characteristics of polymers, solvent residues, the level of organic and inorganic components of a mixture,
degradation temperatures of a material, and the absorbed moisture content of materials. Materials analyzed by
thermogravimetric analysis include explosives, petroleum, chemicals, biological samples, polymers, composites,
plastics, adhesives, coatings, organic materials, and pharmaceuticals.The thermogravimetric analysis instrument usually consists of a high-precision balance and sample pan.
The pan holds the sample
material and is located in a
furnace or oven that is
heated or cooled during the
experiment. A thermocouple
is used to accurately control
and measure the
temperature within the oven.
The mass of the sample is
constantly monitored during
the analysis. An inert or
reactive gas may be used to
purge and control the
environment. The analysis is
performed by gradually
raising the temperature and plotting the
substances weight against temperature. A
computer is utilized to control the
instrument and to process the output
curves.
Heavy-Duty and High torque-to-weight ratios bundled together in a compact motor. Visit hydraulicmotorpump.com to get a hagglands motor if you require a machine to work in toughest conditions being a lightweight machine.
Top 10 bugs in C++ open source projects, checked in 2016PVS-Studio
While the world is discussing the 89th Ceremony of Oscar award and charts of actors and costumes, we've decided to write a review article about the IT-sphere. The article is going to cover the most interesting bugs, made in open source projects in 2016. This year was remarkable for our tool, as PVS-Studio has become available on Linux OS. The errors we present are hopefully, already fixed, but every reader can see how serious are the errors made by developers.
The investigation of thermodynamic properties and reactivity yields interesting insights into the chemistry of newly synthesized substances. With thermal analysis extensive information can be gained from small samples (often only a few milligrams). In addition, the data obtained by thermal analysis can be used to plan and optimize a synthesis. Among the most important applications are identification and purity analysis, and the determination of characteristic temperatures and enthalpies of phase transitions (melting, vaporization), phase transformations, and reactions. Investigations into the kinetics of consecutive reactions and decomposition reactions are also possible. With the instruments available today such analyses can usually be performed quickly and easily. In this review the fundamentals of thermoanalytical methods are described and illustrated with selected examples of applications to low and high molecular weight compounds.
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.
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.
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.
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 .
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.
(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.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
4. Limitations Of TGA
The Chemical or physical changes which are
not accompanied by the change in mass on
heating are not indicated in
thermogravimetric analysis
During TG, Pure fusion reaction, crystalline
transition, glass transition, crystallization
and solid state reation with no volatile
product would not be indicated because they
provide no change in mass of the specimen.
4USMAN ALI
5. 1.Principle
Differential Thermal analysis is a technique in
which the temperature of the substance
under investigation is compared with the
temperature of a thermally inert material
such as a-alumina, and is recorded with
furnace temperature as the substance is
heated or cooled at a predetermined uniform
rate.
The principle of method consists in measuring
the change in temperature associated with
physical or chemical changes during the
gradual heating of the substance.
5USMAN ALI
6. Phenomena causing changes in
Temperature
Physical:
Adsorption (exothermic)
Desorption (endothermic)
A change in crystal structure
(endo – or exothermic)
Crystallization (exothermic)
Melting (endothermic)
Vaporization (endothermic)
Sublimation (endothermic)
6USMAN ALI
7. Chemical:
Oxidation (exothermic)
Reduction (endothermic)
Break down reactions
(endo – or exothermic)
Chemisorption (exothermic)
Solid state reactions
(endo – or exothermic)
Generally speaking, phase transitions,
dehydration, reduction and some decomposition
reactions produce endothermic effects whereas
crystallization, oxidation and some
decomposition reaction produce exothermic
effects.
7USMAN ALI
8. Historical Aspects:
In 1899 Robert Austen
improved this technique
by introducing two
thermocouples, one
placed in sample and
other in the reference
block.
This technique was later
on modified by
Burgess(1909),
Norton(1939),
Grim(1951), Kerr(1948),
Kauffman(1950), Fold
Vari(1958).
8USMAN ALI
10. Characteristics Of DTA Curves
Temperature of the sample is greater
for an exothermic reaction, than that of
reference, for endothermic the sample
temperature lags behind that of
reference
The peak temperature corresponds to
the maximum rate of heat of evolution.
It does not represent the maximum rate
of reaction nor the completion of the
exothermic process.
10USMAN ALI
11. Characteristics Of DTA Curves
DTA curves are not only help in the
identification of materials but their peak
areas provide quantitative information
regarding mass of sample, heat of reactions
(Enthalpy change) and factors such as sample
geometry and thermal conductivity.
If latter two factors are expressed by a factor
“K” called calibration factor, then peak area
can be expressed as:
Peak Area (A) = ±∆ H m K
11USMAN ALI
13. Instrumentation:
1. Source of Uniform Heating:
Nichrome (up to 1300 0C )
Platinum and its alloys (up to 1750 0C )
Molybdenum (up to 2000 0C )
2. Temperature Regulating System:
Electronic Temperature Regulators
3. Specimen Holder:
Pt, Ni, stainless steel, Ag and alloy such as Pt-
Rh
Ceramic material: sintered alumina, silica
13USMAN ALI
14. Instrumentation:
4. Measurement of Temperature:
Rare metal alloys Pt - Rh (Pt 10% - Rh 13%)
used as thermocouple
W - Mo also used as thermocouple
5. Temperature Recording System:
Galvanometric Observation ( For few
samples)
Automatic pen
Ink electronic Recorder
14USMAN ALI
15. Factors Affecting DTA Curves:
DTA is a dynamic temperature technique.
Therefore, a large number of factors can affect.
These factors can be divided into the two
groups:
i) Instrumental factors
ii) Sample factors
15USMAN ALI
16. Factors Affecting DTA Curves:
Instrumental Factors:
Size and shape of sample holder
Sample holder material
Heating rate of sample
Sensitivity of recording system
Location of thermocouple in the sample
Atmosphere around sample
16USMAN ALI
17. Factors Affecting DTA Curves:
Sample characteristics:
Amount of sample
Particle size
Packing density
Heat capacity
Thermal conductivity
Degree of crystallinity
Dilutes of diluents
Swelling and shrinking of sample
17USMAN ALI
20. Applications
The important applications of DTA are:
Rapid identification of the composition
of mixed clays
Studying the thermal stabilities of
inorganic compounds
Critically examining in a specific
reaction whether a new compound is
actually formed or the product is
nothing but an unreacted original
substance 20USMAN ALI
21. Applications
DTA offers a wide spectrum of useful
investigations related to reaction
kinetics, polymerization, solvent -
retention, phase-transformations, solid-
phase reactions and curing or drying
properties of a product
21USMAN ALI