16 research outputs found
Correlation of Pap smear and visual inspection with acetic acid for screening of premalignant and malignant lesion of cervix
Background: Cervical cancer still remains a leading cause of morbidity and mortality among women worldwide. Despite attempts to increase screening over the past several decades, incidence and mortality rates of cancer cervix have not shown substantial reduction. The conventional method of screening by cervical cytology/pap smear has failed to reduce the disease burden due to lack of patient compliance for repeated testing and a relatively sophisticated infrastructure. Therefore, alternative methods such as visual inspection after application of acetic acid (VIA), visual inspection with Lugol's Iodine (VILI) and human papillomavirus (HPV) DNA testing have been developed. The aim of present study was to compare Pap smear and VIA and evaluate their usefulness as tools for screening of premalignant and malignant lesions of cervix.Methods: This was a crossectional study over 5 months from 1 Jan 2015 to 31 may 2015 in which 212 patients attending the obstetrics and gynecology department, BHU were enrolled. Pap smear was taken followed by VIA. Pap smears were sent to pathology department, BHU where they were reported as per Bethesda System, 2001. Cervical biopsies were done in positive cases. Data obtained and statistically analyzed.Results: The present study was conducted over a period of 6 months among 212 patients age of 18-60 years screened. Positive results obtained from cytology were 26, VIA was positive in 28 women. Cervical biopsy was done in 34 women who had positive results by either test. Histology in 31 cases was suggestive of cervical intraepithelial carcinoma (CIN).Conclusions: VIA, though less specific has comparable sensitivity to Pap smear and may be used as a primary screening tool for cervical cancer. In combination both the tests have a higher predictive accuracy.
Near-field imaging of surface-plasmon vortex-modes around a single elliptical nanohole in a gold film
We present scanning near-field images of surface plasmon modes around a
single elliptical nanohole in 88 nm thick Au film. We find that rotating
surface plasmon vortex modes carrying extrinsic orbital angular momentum can be
induced under linearly polarized illumination. The vortex modes are obtained
only when the incident polarization direction differs from one of the ellipse
axes. Such a direct observation of the vortex modes is possible thanks to the
ability of the SNOM technique to obtain information on both the amplitude and
the phase of the near field. The presence of the vortex mode is determined by
the rotational symmetry breaking of the system and it can be considered the
counterpart of the photonic spin Hall effect. Finite element method
calculations show that such a vorticity originates from the presence of nodal
points where the phase of the field is undefined, leading to a circulation of
the energy flow. The configuration producing vortex modes corresponds to a
nonzero total topological charge (+1)
Nonlinear Optical Properties of Polyynes: An Experimental Prediction for Carbyne
We present the experimental determination of the vibrational contribution to molecular second hyperpolarizability (Îvib) of very long polyynes that have been recently made available thanks to progress in chemical synthesis. Based on a simple theoretical model, the available experimental data allow estimating the asymptotic behavior of the vibrational contribution to molecular hyperpolarizability for increasing chain length
High incidence of zidovudine induced anaemia in HIV infected patients in eastern India
Background & objectives: Zidovudine (ZDV) is the preferred nucleoside reverse transcriptase inhibitor in the first line antiretroviral regimen in India. It is known to be associated with life threatening toxicity like anaemia. This study was aimed at determining the prevalence of ZDV induced anaemia in HIV infected patients initiated on ZDV containing antiretroviral therapy regimen and also to find out the correlates, if any, for causing ZDV induced anaemia.
Methods: This retrospective study was carried in ART Centre, Sir Sunderlal Hospital, Banaras Hindu University, Varanasi between March 2005 to December 2007. HIV infected patients registered at ART Centre were treated according to guidelines of National AIDS Control Organization (NACO). Patients (n=1256) with haemoglobin (Hb) >8 g/dl were prescribed ZDV based antiretroviral therapy regimens. Patients developing anaemia (<8 g/dl) with other causes of anaemia excluded were recorded. Correlation of baseline characteristics (age, gender, haemoglobin levels, weight, CD4 counts and WHO clinical stage) with risk of developing anaemia was also calculated.
Results: Two hundred three (16.2%) patients on ZDV regimen developed anaemia (<8 g%); 7.9 per cent (n=100) of these developed severe anaemia (<6.5 g%). Females were more prone to develop anaemia (P=0.026). Age, weight, WHO clinical stage and CD4 counts had no relation to development of anaemia.
Interpretation & conclusion: High incidence of ZDV induced anaemia seen in this study indicates regular monitoring of patients, particularly women on ZDV based antiretroviral regimens
Classification of Cannabinoid Spectra Using Machine Learning
Vibrational spectroscopy, encompassing Raman and Infrared (IR) spectroscopy, is a powerful technique that probes the intrinsic vibrations of a molecule, thus providing a unique chemical signature for that molecule. This information is beneficial to differentiate between two similarly structured molecules since their vibrational fingerprint will be different. In an effort to introduce an automated spectroscopic data analysis tool, we explore different Machine Learning (ML) algorithms to identify the chemical structure from the simulated Raman and IR spectra of 22 similar molecules belonging to the class of cannabinoids.
In this study, we investigate the best ML approach by using representative synthetic IR/Raman data obtained from quantum chemical calculations of the selected molecular structures. We account for the experimental variability of the spectra by adding different kinds of noise and backgrounds to the simulated spectra such that they mimic experimental conditions such as fluorescence background as well as Gaussian noise. This methodology is used to setup the database to train the ML algorithms. We report the accuracy of the different ML algorithms and the time taken to process the algorithms in differentiating the cannabinoid varieties
Non-Linear Microscopy of Mitochondrial Damage and Abnormal Lipid Metabolism in Beta-Amyloid Expressing Yeast
Non-Linear Microscopy of Mitochondrial Damage and Abnormal Lipid Metabolism in Beta-Amyloid Expressing Yeast
X-radiation enhances the collagen type I strap formation and migration potentials of colon cancer cells
Rectal cancer treatment still fails with local and distant relapses of the disease. It is hypothesized that radiotherapy could stimulate cancer cell dissemination and metastasis. In this study, we evaluated the effect of X-radiation on collagen type I strap formation potential, i.e. matrix remodeling associated with mesenchymal cell migration, and behaviors of SW480, SW620, HCT116 p53(+/+) and HCT116 p53(-/-) colon cancer cells. We determined a radiation-induced increase in collagen type I strap formation and migration potentials of SW480 and HCT116 p53(+/+). Further studies with HCT116 p53(+/+), indicated that after X-radiation strap forming cells have an increased motility. More, we detected a decrease in adhesion potential and mature integrin beta 1 expression, but no change in non-muscle myosin II expression for HCT116 p53(+/+) after X-radiation. Integrin beta 1 neutralization resulted in a decreased cell adhesion and collagen type I strap formation in both sham and X-radiated conditions. Our study indicates collagen type I strap formation as a potential mechanism of colon cancer cells with increased migration potential after X-radiation, and suggests that other molecules than integrin beta 1 and non-muscle myosin II are responsible for the radiation-induced collagen type I strap formation potential of colon cancer cells. This work encourages further molecular investigation of radiation-induced migration to improve rectal cancer treatment outcome.Funding Agencies|Swedish Cancer Foundation; Swedish Research Council; Wallenberg Foundation; Health Research Council in South-East Sweden</p
Correlating topography and viscoelastic properties of Elastin-Like Polypeptide scaffolds probed at the nanoscale: Intermodulation Atomic Force Microscopy
The synthesis and property characterization of soft biomaterials has taken precedence in recent years. Although bulk physical-chemical properties are well known for these bio-materials, nanoscale properties still need to be probed and evaluated to fine tune the bio-compatibility (structural as well as functional) with natural tissues for regenerative medicine, prosthetics and other biological applications. In this study, we focus on a popular soft biomaterial, ELastin-like polypeptide (ELP) which has been prepared under different pH conditions. We explore the topographical features of the ELP at the nanoscale using Atomic Force Microscopy (AFM). Additionally, we employ a non linear mode of AFM called Intermodulation-AFM (ImAFM) to correlate the elastic properties (Young\u27s modulus) of ELP probed at the nanoscale with the topographical features which gives us a deep insight into the mechanical properties offered by ELP when the structural features are altered by change in the ELP synthesis conditions. The noteworthy point is that we measure theses properties at a spatial resolution of 0.9 nm. Finally, we explain the change in the structural features of ELP with varying pH through atomistic Molecular Dynamics Simulations. We follow the interaction mechanisms of the amino acid sequences and crosslinkers with proteins as they form the backbone and sidechain of the ELP at different pH
SERS detection and DFT calculation of 2-naphthalene thiol adsorbed on Ag and Au probes
Two different surface enhanced Raman scattering (SERS) sensors are described, tested and compared against the detection of 2-naphthalenethiol (2NPT, a volatile compound) in both solution state as well as vapor phase. The first sensor is based on an optical fiber properly modeled to induce the adhesion of colloidal Ag nanoparticles on its surface. Excitation and detection of the Raman signal is performed through the optical fiber that can be used as in situ probe for the detection of molecules adsorbed on the SERS sensitized surface. The second SERS sensor is based on nanostructured substrates consisting of Au nanoparticles produced by pulsed laser deposition in presence of a controlled Ar atmosphere. Details at the nanometer scale were observed by SEM and TEM imaging to understand the size and structure of the islands formed as a function of deposition parameters that were selected in order to maximize their SERS response. The sensitivity of the substrates to volatile species was tested by letting evaporate controlled drops of a methanol solution of 2NPT in a chamber of known volume, where the substrate was placed. After complete evaporation of the drops, this provided an in-situ environment suitable for vapor phase measurements at known concentration. SERS spectra were collected after exposing the substrates to the environment within the chamber (vapor phase measurements) or dipping them in a solution for condensed state measurements. The complete absence of the SH stretching peak in the SERS spectra proves the covalent bonding of 2NPT to the metal substrates via the sulfur atom. DFT calculations, including metal-sulfur interaction, provide a good description of the observed SERS spectra. The reported data allow concluding that our SERS substrates are suitable for detection of volatile compounds