16 research outputs found
Tomographic measurement of all orthogonal components of three-dimensional displacement fields within scattering materials using wavelength scanning interferometry
Experimental mechanics is currently contemplating tremendous opportunities of further
advancements thanks to a combination of powerful computational techniques and also fullfield
non-contact methods to measure displacement and strain fields in a wide variety of
materials. Identification techniques, aimed to evaluate material mechanical properties given
known loads and measured displacement or strain fields, are bound to benefit from increased
data availability (both in density and dimensionality) and efficient inversion methods such as
finite element updating (FEU) and the virtual fields method (VFM). They work at their best
when provided with dense and multicomponent experimental displacement (or strain) data,
i.e. when all orthogonal components of displacements (or all components of the strain tensor)
are known at points closely spaced within the volume of the material under study. Although a
very challenging requirement, an increasing number of techniques are emerging to provide
such data.
In this Thesis, a novel wavelength scanning interferometry (WSI) system that provides three
dimensional (3-D) displacement fields inside the volume of semi-transparent scattering
materials is proposed. Sequences of two-dimensional interferograms are recorded whilst
tuning the frequency of a laser at a constant rate. A new approach based on frequency
multiplexing is used to encode the interference signal corresponding to multiple illumination
directions at different spectral bands. Different optical paths along each illumination direction
ensure that the signals corresponding to each sensitivity vector do not overlap in the
frequency domain. All the information required to reconstruct the location and the 3-D
displacement vector of scattering points within the material is thus recorded simultaneously
in a single wavelength scan. By comparing phase data volumes obtained for two successive
scans, all orthogonal components of the three dimensional displacement field introduced
between scans (e.g. by means of loading or moving the sample under study) are readily
obtained with high displacement sensitivity.
The fundamental principle that describes the technique is presented in detail, including the
correspondence between interference signal frequency and its associated depth within the
sample, depth range, depth resolution, transverse resolution and displacement sensitivity.
Data processing of the interference signal includes Fourier transformation, noise reduction,
re-registration of data volumes, measurement of the illumination and sensitivity vectors from
experimental data using a datum surface, phase difference evaluation, 3-D phase unwrapping and 3-D displacement field evaluation.
Experiments consisting of controlled rigid body rotations and translations of a phantom were performed to validate the results. Both in-plane and the out-of-plane displacement components were measured for each voxel in the resulting data volume, showing an excellent agreement with the expected 3-D displacement
Tomographic imaging of all orthogonal components of the displacement field in weakly scattering materials using wavelength scanning interferometry
This paper presents a wavelength scanning interferometry system which provides displacement fields
inside the volume of semi-transparent scattering materials with high spatial resolution and threedimensional
displacement sensitivity. This technique can be viewed as frequency multiplexed sweptsource
OCT in which different channels carry information for specific displacement sensitivities
Genetic Basis And Clinical Perspectives Of Breast Cancer
Breast cancer, a widespread malignancy affecting women, originates in the epithelial tissues of the breast. This study explores the significance of BRCA1 and BRCA2 genes in breast cancer etiology. Approximately 5% to 10% of breast cancer cases are hereditary, resulting from germline mutations in these genes. BRCA mutations increase the risk of breast cancer, with carriers facing a likelihood of 45% to 75% of developing the disease. Additionally, the aggressive phenotype of BRCA-related breast cancers is marked by features like triple-negative attributes and higher grades. In India, the incidence of breast cancer is escalating, projected to reach 250,000 cases by 2030. Alarming mortality rates underscore the necessity for effective interventions. The five-stage classification of breast cancer—from non-invasive disease in Stage 0 to metastatic spread in Stage IV—provides a framework for diagnosis and treatment. Earlystage breast cancers are manageable with surgery and hormone therapy. In locally advanced breast cancer (Stage III), a combination ofchemotherapy and surgery is employed after metastatic spread to lymph nodes and other sites. Stage IV breast cancer, representing the most advanced phase, presents significant treatment challenges. Current therapies encompass systemic drugs, radiation therapy, chemotherapy, and surgery, although achieving a definitive cure remains elusive. This study emphasizes the crucial role of BRCA mutations in breast cancer susceptibility, stressing the importance of genetic screening and targeted interventions. Furthermore, it explores the complexities of disease staging, guiding treatment strategies based on disease extent. Despite considerable progress, continuous research efforts are essential to enhancing diagnostic precision and developing more effective treatments for this intricate and multifaceted disease (Łukasiewicz et al., 2021; Smolarz et al., 2022)
Revolutionizing the Biological Landscape: the Power of Genome Editing
In recent decades, the advent of genome editing has brought about profound transformations in biology, allowing for precise modifications to the genetic material of living organisms beyond traditional genetic manipulation methods. This summary explores the vast potential, diverse applications, and ethical considerations associated with genome editing. Led by CRISPR-Cas9, this technology revolutionizes genetic engineering by providing unparalleled accuracy and versatility. Scientists can now manipulate genes with unprecedented precision, impacting various fields such as agriculture and medicine. Genome editing facilitates the creation of genetically modified organisms with desirable traits, from enhancing crop disease resistance to pioneering human therapies. Moreover, it sheds light on gene function, offering crucial biological insights. Despite its transformative potential, ethical concerns accompany genome editing, especially in terms of editing the germ line and its implications for future generations. This necessitates ongoing discussions to address unintended consequences, highlighting the importance of responsible use. Ultimately, genome editing represents a revolutionary advancement with the potential to transform agriculture, medicine, and our understanding of life. Moving forward, inclusive dialogues involving scientists, ethicists, policymakers, and the public are essential to ensure the responsible application of genome editing for the benefit of humanity and the environment
Submicron scale tissue multifractal anisotropy in polarized laser light scattering
The spatial fluctuations of the refractive index within biological tissues exhibit multifractal anisotropy, leaving its signature as a spectral linear diattenuation of scattered polarized light. The multifractal anisotropy has been quantitatively assessed by the processing of relevant Mueller matrix elements in the Fourier domain, utilizing the Born approximation and subsequent multifractal analysis. The differential scaling exponent and width of the singularity spectrum appear to be highly sensitive to the structural multifractal anisotropy at the micron/sub-micron length scales. An immediate practical use of these multifractal anisotropy parameters was explored for non-invasive screening of cervical precancerous alterations ex vivo, with the indication of a strong potential for clinical diagnostic purposes
Exosomal RNA: Interplay and Therapeutic Potential
Exosomal RNA has emerged as a crucial mediator of intercellular communication, enabling the transfer of genetic information between cells. This intricate signaling system holds great promise for unraveling complex cellular processes and advancing therapeutic applications. This review provides an in-depth examination of the current state of knowledge regarding exosomal RNA, emphasizing its role in intercellular signaling and its relevance to various physiological and pathological conditions. Furthermore, we explore the potential therapeutic applications that leverage exosomal RNA, opening new avenues for innovative treatments across diverse medical domains. The nuanced interplay of exosomal RNA presents a fertile ground for further investigation and application, promising advancements in both fundamental biology and clinical interventions
CHARGE Association
We present here a case of 17-year-old boy from Kolkata presenting with obesity, bilateral gynecomastia, mental retardation, and hypogonadotrophic hypogonadism. The patient weighed 70 kg and was of 153 cm height. Facial asymmetry (unilateral facial palsy), gynecomastia, decreased pubic and axillary hair, small penis, decreased right testicular volume, non-palpable left testis, and right-sided congenital inguinal hernia was present. The patient also had disc coloboma, convergent squint, microcornea, microphthalmia, pseudohypertelorism, low set ears, short neck, and choanalatresia. He had h/o VSD repaired with patch. Laboratory examination revealed haemoglobin 9.9 mg/dl, urea 24 mg/dl, creatinine 0.68 mg/dl. IGF1 77.80 ng/ml (decreased for age), GH <0.05 ng/ml, testosterone 0.25 ng/ml, FSH-0.95 ΅IU/ml, LH 0.60 ΅IU/ml. ACTH, 8:00 A.M cortisol, FT3, FT4, TSH, estradiol, DHEA-S, lipid profile, and LFT was within normal limits. Prolactin was elevated at 38.50 ng/ml. The patient′s karyotype was 46XY. Echocardiography revealed ventricularseptal defect closed with patch, grade 1 aortic regurgitation, and ejection fraction 67%. Ultrasound testis showed small right testis within scrotal sac and undescended left testis within left inguinal canal. CT scan paranasal sinuses revealed choanalatresia and deviation of nasal septum to the right. Sonomammography revealed bilateral proliferation of fibroglandular elements predominantly in subareoalar region of breasts. MRI of brain and pituitary region revealed markedly atrophic pituitary gland parenchyma with preserved infundibulum and hypothalamus and widened suprasellar cistern. The CHARGE association is an increasingly recognized non-random pattern of congenital anomalies comprising of coloboma, heart defect, choanal atresia, retarded growth and development, genital hypoplasia, ear abnormalities, and/or deafness. [1] These anomalies have a higher probability of occurring together. In this report, we have described a boy with CHARGE association
Measurement of all orthogonal components of displacement in the volume of scattering materials using wavelength scanning interferometry
A wavelength scanning interferometry system is proposed that provides displacement fields inside the volume of semitransparent scattering materials with high spatial resolution and three-dimensional (3D) displacement sensitivity. This effectively extends digital speckle pattern interferometry into three dimensions. The sample is illuminated by three noncoplanar collimated beams around the observation direction. Sequences of two-dimensional interferograms are recorded while tuning the laser frequency at a constant rate. Different optical paths along each illumination direction ensure that the signals corresponding to each sensitivity vector do not overlap in the frequency domain. All the information required to reconstruct the location and the 3D displacement vector of scattering points within the material is thus recorded simultaneously. A controlled validation experiment is performed, which confirms the ability of the technique to provide 3D displacement distributions inside semitransparent scattering materials. © 2012 Optical Society of America