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1.
Appl Opt ; 63(13): 3585-3599, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38856544

ABSTRACT

This paper reports the effect of a magnetic field on plasma parameters and surface structuring of the Mg alloy after laser irradiation. Femtosecond pulses of a Ti:sapphire laser system (800 nm, 35 fs, 1 KHz) are employed as the source of irradiation at various irradiances ranging from 0.011P W/c m 2 to 0.117P W/c m 2 to generate ablated Mg-alloy plasma. A transvers magnetic field (TMF) of strength 1.1 Tesla is employed to confine laser generated Mg plasma. All the measurements are performed with and without TMF. The two plasma parameters, i.e., excitation temperature (T e x c ) and electron number density (n e) of Mg plasma, have been evaluated by laser-induced breakdown spectroscopy (LIBS) analysis. It is observed that the values of T e x c and n e of laser produced plasma (LPP) of the Mg alloy are higher in the presence of a magnetic field as compared to the field free case. Both show initially an increasing trend with increasing laser irradiance and after attaining their respective maxima a decreasing trend is observed with the further increase of irradiance. The magnetic confinement validity is confirmed by analytically evaluating thermal beta (ß t), directional beta (ß d), confinement radius (R b), and diffusion time (t d) for LPP of the Mg alloy. To correlate the LPP parameters of the Mg alloy with surface modifications a field emission scanning electron microscope (FE-SEM) analysis is performed. It was revealed that structures like laser-induced periodic surface structures (LIPSSs), agglomerates, islands, large sized bumps, along with channels and multiple ablative layers are observed. Distinct and well-defined surface structuring is observed in the presence of TMF as compared to the field free case. It is concluded that by applying an external magnetic field during laser irradiation, controlled material surface structuring is possible for fabrication of nanogratings and field emitters where spatial uniformity is critically important.

2.
Indian J Surg Oncol ; 15(1): 145-148, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38511037

ABSTRACT

Peritoneal malignant mesothelioma is an uncommon neoplasm with a poor prognosis. We hereby report a case of a 20-year-old male, first diagnosed on biopsy with axillary lymph node metastasis. He presented with abdominal pain and axillary lymphadenopathy, with no history of asbestos exposure. CECT showed peritoneal thickening and ascites. Ascitic fluid cytology showed reactive morphology. The diagnosis of metastatic deposits of malignant mesothelioma was made on histopathology and confirmed by immunohistochemistry. Tumor cells were immune-reactive for CK 5/6, calretinin, D2-40, and WT1 and negative for TTF1, CK 20, and CD 3. This case report has two important highlights-(i) unusual presentation with axillary lymph node metastasis leading to diagnostic dilemma in a young male with no asbestos exposure history and (ii) confirmatory diagnostic role of IHC in Peritoneal malignant mesothelioma.

3.
Heliyon ; 9(8): e18781, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37593619

ABSTRACT

In this paper, we explore the surface and mechanical alterations of Cu, as well as the parameters of laser-assisted plasma and ablation. The irradiation source is a Nd: YAG laser with a constant irradiance of 1.0 GW/cm2 (1064 nm, 55 mJ, 10 ns, 10 Hz). Physical parameters such as electron temperature (Te) and electron number density (ne), sputtering yield (yield), ablation depth (depth), surface morphology (morphology), and hardness (Vickers) of laser irradiated Cu are evaluated using instruments such as a Laser Induced Breakdown Spectrometer (LIBS), Quartz Crystal Microbalance (QCM), Optical Emission Microscope (OEM), Scanning Electron Microscope (SEM), and Vicker's hardness tester. These physical characteristics have been studied in relation to changes in pressure (from 10 torr to 100 torr) and the composition of two inert ambient gases (Argon and Neon). Pressures of Ar and Ne are found to enhance the emission intensities of spectral lines of Cu, Te, and ne, as well as the sputtering yield, crater depth, and hardness of laser ablated Cu, to a maximum at 60 torr, after which they decrease with subsequent increases in pressure up to 100 torr. Increases in pressure up to 60 torr are connected with plasma confinement effects and increased collisional frequency, whereas decreases in pressure between 60 and 100 torr are ascribed to shielding effects by the plasma plume. All numbers are also found to be greater in Ar compared to Ne. In Ar, laser-ablated Cu reaches a maximum of 15218 K, 1.83 × 1018 cm-3, 8.59 × 1015 atoms/pulse, 231 m, and 147 HV, whereas in Ne, it reaches a maximum of 12000 K, 1.75 × 1018 cm-3, 7.70 × 1015 atoms/pulse, 200 m, and 116 HV. Ar is more likely than Ne to develop surface features such as craters, distinct melting pools with elevating edges, flakes, cones, etc. It is also shown that there is a significant association between the outcomes, with an increase in Te and ne being responsible for a rise in sputtering yield, ablation depth, surface morphology, and surface hardness. These findings have potential uses in plasma spectroscopy for materials science and in industrial applications of Cu.

4.
Sci Rep ; 13(1): 13474, 2023 08 18.
Article in English | MEDLINE | ID: mdl-37596340

ABSTRACT

The encapsulation of plant extract in nanomatrices has limitations due to its adhesion to walls, size control, high cost and long durations that results in low yield. Macroscale and microscale level techniques for development of micro/nanoparticles may impact the encapsulation of plant extract. This study aimed to evaluate the relative efficiency of microscale and macroscale techniques for encapsulation of plant extract, which is not compared yet. Keeping this in view, encapsulation of Calotropis gigantea leaves extract (CaG) was attained in silver-conjugated poliglusam nanomatrices (POL/Ag) to induce apoptosis in invasive ductal carcinoma (IDC) cells. The ethanolic CaG extract was prepared using percolation method and characterized by chemical tests for its active phytochemical compounds. The droplet-based microfluidic system was utilized as microscale encapsulation technique for CaG in nanomatrices at two different aqueous to oil flow rate ratios 1.0:1.5, and 1.0:3.0. Moreover, conventional batch system was utilized as macroscale encapsulation technique consisted of hot plate magnetic stirrer. The prepared nanomatrices were analysed for antioxidant activity using DPPH test and for cytotoxicity analysis using MCF-7 cells. The characteristic peaks of UV-Vis, FTIR and XRD spectrum confirmed the synthesis of CaG(POL/Ag) by both the encapsulation methods. However, microfluidic system was found to be more expedient because of attaining small and uniform sized silver nanoparticles (92 ± 19 nm) at high flow rate and achieving high encapsulation efficiency (80.25%) as compared to the conventional batch method (52.5%). CaG(POL/Ag) nanomatrices found to have significant antioxidant activity (p = 0.0014) against DPPH radical scavenging activity. The CaG(POL/Ag) of the smallest sized formulated by the microfluidic system has also shown the highest cytotoxicity (90%) as compared to batch method (70%) at 80 µg/mL. Our results indicate that the microscale technique using microfluidic system is a more efficient method to formulate size-controlled CaG(POL/Ag) nanomatrices and achieve high encapsulation of plant extract. Additionally, CaG(Pol/Ag) was found to be an efficient new combination for inducing potent (p < 0.0001) apoptosis in IDC cells. Therefore, CaG(Pol/Ag) can be further tested as an anti-cancer agent for in-vivo experiments.


Subject(s)
Calotropis , Carcinoma, Ductal , Metal Nanoparticles , Silver , Antioxidants/pharmacology , Plant Extracts/pharmacology
5.
Heliyon ; 9(8): e18676, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37554841

ABSTRACT

The use of nanomaterials as a means of recovering heavy and light oil from petroleum reservoirs has increased over the preceding twenty years. Most researchers have found that injecting a nanoparticle dispersion (nanofluids) has led to good results and increased the amount of oil that can be recovered. In this research, we aim to imitate the three-dimensional hexagonal prism in the existence of SiO2 and Al2O3 nanoparticles for better oil recovery. Porosity (0.1≤φ≤0.4), mass flow rate (0.05mL/min≤Q≤0.05ml/min), nanoparticle concentration (0.01≤ψ≤0.04), and the effect of relative permeability (kr) on oil and water saturation in the presence of gravity under different time durations are all investigated. The result obtained for the model is verified with existing experimental data. The results indicated that the infulence of nanoparticle volume fraction (VF) is significant in enhancing the oil recovery rate. It is also observed that at low porosity values the oil recovery is maximum. The maximum oil recovery is attained at low values of mass flow rate in the 3D hexagonal prism in the presence of silicon and aluminium nanoparticles It is also observed that the use of SiO2 gives a better oil recovery rate than Al2O3. It is also observed that maximum oil recovery is obtained at 99% at a flow rate of 0.05 mL/min in the presence of silicon injection.

6.
Materials (Basel) ; 16(11)2023 May 27.
Article in English | MEDLINE | ID: mdl-37297145

ABSTRACT

Enhanced oil recovery (EOR) has been offered as an alternative to declining crude oil production. EOR using nanotechnology is one of the most innovative trends in the petroleum industry. In order to determine the maximum oil recovery, the effect of a 3D rectangular prism shape is numerically investigated in this study. Using ANSYS Fluent software(2022R1), we develop a two-phase mathematical model based on 3D geometry. This research examines the following parameters: flow rate Q = 0.01-0.05 mL/min, volume fractions = 0.01-0.04%, and the effect of nanomaterials on relative permeability. The result of the model is verified with published studies. In this study, the finite volume method is used to simulate the problem, and we run simulations at different flow rates while keeping other variables constant. The findings show that the nanomaterials have an important effect on water and oil permeability, increasing oil mobility and lowering IFT, which increases the recovery process. Additionally, it has been noted that a reduction in the flow rate improves oil recovery. Maximum oil recovery was attained at a 0.05 mL/min flow rate. Based on the findings, it is also demonstrated that SiO2 provides better oil recovery compared to Al2O3. When the volume fraction concentration increases, oil recovery ultimately increases.

7.
PLoS One ; 18(3): e0278277, 2023.
Article in English | MEDLINE | ID: mdl-36867625

ABSTRACT

Intensive tilapia farming has contributed significantly to food security as well as to the emergence of novel pathogens. This includes Streptococcus agalactiae or Group B Streptococcus (GBS) sequence type (ST) 283, which caused the first known outbreak of foodborne GBS illness in humans. An oral, easy-to-administer fish vaccine is needed to reduce losses in fish production and the risk of zoonotic transmission associated with GBS. We conducted a proof-of-concept study to develop an oral vaccine formulation that would only release its vaccine cargo at the site of action, i.e., in the fish gastrointestinal tract, and to evaluate whether it provided protection from experimental challenge with GBS. Formalin-inactivated S. agalactiae ST283, was entrapped within microparticles of Eudragit® E100 polymer using a double-emulsification solvent evaporation method. Exposure to an acidic medium simulating the environment in tilapia stomach showed that the size of the vaccine-loaded microparticles decreased rapidly, reflecting microparticle erosion and release of the vaccine cargo. In vivo studies in tilapia showed that oral administration of vaccine-loaded microparticles to fish provided significant protection from subsequent homologous pathogen challenge with GBS ST283 by immersion compared to the control groups which received blank microparticles or buffer, reducing mortality from 70% to 20%. The high efficacy shows the promise of the vaccine platform developed herein, which might be adapted for other bacterial pathogens and other fish species.


Subject(s)
Foodborne Diseases , Tilapia , Animals , Humans , Streptococcus agalactiae , Proof of Concept Study , Administration, Oral , Hydrogen-Ion Concentration
8.
Nanotechnology ; 34(26)2023 Apr 13.
Article in English | MEDLINE | ID: mdl-36996770

ABSTRACT

Metal oxide-based sensors have the benefit of inexpensive, quick response, and high sensitivity in detecting specific biological species. In this article, a simple electrochemical immunosensor was fabricated using antibody-chitosan coated silver/cerium oxide (Ab-CS@Ag/CeO2) nanocomposites on a gold electrode for sensitive alpha-fetoprotein (AFP) diagnosis in human serum samples. Successfully synthesis of AFP antibody-CS@Ag/CeO2conjugates was confirmed through Fourier transform infrared spectra of the prototype. The amine coupling bond chemistry was then used to immobilize the resultant conjugate on a gold electrode surface. It was observed that the interaction of the synthesized Ab-CS@Ag/CeO2nanocomposites with AFP prevented an electron transfer and reduced the voltammetric Fe(CN)63-/4-peak current, which was proportional to the amount of AFP. The linear ranges of AFP concentration were found from 10-12-10-6g.ml-1. The limit of detection was calculated using the calibration curve and came out to be 0.57 pg.ml-1. The designed label-free immunosensor successfully detected AFP in human serum samples. As a result, the resulting immunosensor is a promising sensor plate form for AFP detection and could be used in clinical bioanalysis.


Subject(s)
Biosensing Techniques , Chitosan , Metal Nanoparticles , Nanocomposites , Humans , alpha-Fetoproteins/analysis , Silver/chemistry , Biosensing Techniques/methods , Immunoassay/methods , Oxides , Antibodies , Nanocomposites/chemistry , Gold/chemistry , Electrochemical Techniques/methods , Limit of Detection , Metal Nanoparticles/chemistry
9.
Eur J Pharm Sci ; 182: 106374, 2023 Mar 01.
Article in English | MEDLINE | ID: mdl-36623699

ABSTRACT

Therapeutic proteins and peptides (TPPs) are increasingly favoured above small drug molecules due to their high specificity to the site of action and reduced adverse effects resulting in increased use of these agents for medical treatments and therapies. Consequently, there is a need to formulate TPPs in dosage forms that are accessible and suitable for a wide range of patient groups as the use of TPPs becomes increasingly prevalent in healthcare settings worldwide. Orally disintegrating dosage forms (ODDF) are formulations that can ensure easy-to-administer medication to a wider patient population including paediatrics, geriatrics and people in low-resource countries. There are many challenges involved in developing suitable pharmaceutical strategies to protect TPPs during formulation and manufacturing, as well as storage, and maintenance of a cold-chain during transportation. This review will discuss advances being made in the research and development of pharmaceutical and manufacturing strategies used to incorporate various TPPs into ODDF systems.


Subject(s)
Drug Delivery Systems , Peptides , Child , Humans , Administration, Oral , Dosage Forms , Drug Delivery Systems/methods , Pharmaceutical Preparations/chemistry , Tablets/chemistry , Aged
10.
Int J Mol Sci ; 23(21)2022 Oct 22.
Article in English | MEDLINE | ID: mdl-36361538

ABSTRACT

In the present study KrF Excimer laser has been employed to irradiate the Cadmium (Cd) targets for various number of laser pulses of 500, 1000, 1500 and 2000, at constant fluence of 3.6 J cm-2. Scanning Electron Microscopy (SEM) analysis was utilized to reveal the formation of laser induced nano/micro structures on the irradiated target (Cd) surfaces. SEM results show the generation of cavities, cracks, micro/nano wires/rods, wrinkles along with re-deposited particles during irradiation in air, whereas subsurface boiling, pores, cavities and Laser Induced Periodic Surface Structures (LIPSS) on the inner walls of cavities are revealed at the central ablated area after irradiation in propanol. The ablated volume and depth of ablated region on irradiated Cd targets are evaluated for various number of pulses and is higher in air as compared to propanol ambient. Fast Fourier Transform Infrared spectroscopy (FTIR), Energy Dispersive X-ray Spectroscopy (EDS) and X-ray Diffraction (XRD) analyses show the presence of oxides and hydro-oxides of Cd after irradiation in propanol, whereas the existence of oxides is observed after irradiation in air ambient. Nano-hardness tester was used to investigate mechanical modifications of ablated Cd. It reveals an increase in hardness after irradiation which is more pronounced in propanol as compared to air.


Subject(s)
1-Propanol , Cadmium , Lasers , Microscopy, Electron, Scanning , Oxides
11.
Biomed Res Int ; 2022: 1300157, 2022.
Article in English | MEDLINE | ID: mdl-35155669

ABSTRACT

In the present work, multiwalled carbon nanotube (MWCNT)/zinc oxide (ZnO) nanoparticles at pH 6.0, 7.0, 8.0, and 10.0 were prepared through the coprecipitation method to improve the antibacterial activity. Morphological, structural, and optical analysis, such as Fourier transform infrared spectroscopy, X-ray diffraction, and field emission scanning electron microscopy, was used to investigate the formation of composites. Analysis revealed that there were variations in morphology from agglomerated structures to rod-like then flower-like structures as pH varied from 6.0 to 10.0. The MWCNT/ZnO composite enhanced the antibacterial activity especially for Staphylococcus aureus as a maximum 20 mm zone of inhibition was observed. The data presented in the present study proves that such composites are an efficient antibacterial agent and suitable for therapy for severe infections.


Subject(s)
Anti-Bacterial Agents/chemistry , Nanotubes, Carbon , Zinc Oxide/chemistry , Hydrogen-Ion Concentration , Microbial Sensitivity Tests , Staphylococcus aureus/drug effects , Zinc Oxide/pharmacology
12.
Materials (Basel) ; 14(13)2021 Jun 30.
Article in English | MEDLINE | ID: mdl-34209319

ABSTRACT

Micro/nano structuring of KrF Excimer laser-irradiated Aluminum (Al) has been correlated with laser-produced structural and mechanical changes. The effect of non-reactive Argon (Ar) and reactive Oxygen (O2) environments on the surface, structural and mechanical characteristics of nano-second pulsed laser-ablated Aluminum (Al) has been revealed. KrF Excimer laser with pulse duration 20 ns, central wavelength of 248 nm and repetition rate of was utilized for this purpose. Exposure of targets has been carried out for 0.86, 1, 1.13 and 1.27 J·cm-2 laser fluences in non-reactive (Ar) and reactive (O2) ambient environments at a pressure of 100 torr. A variety of characteristics of the irradiated targets like the morphology of the surface, chemical composition, crystallinity and nano hardness were investigated by using Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Energy Dispersive X-ray Spectroscopy (EDS), X-ray Diffractometer (XRD), Raman spectroscopy and Nanohardness tester techniques, respectively. The nature (reactive or non-reactive) and pressure of gas played an important role in modification of materials. In this study, a strong correlation is observed between the surface structuring, chemical composition, residual stress variation and the variation in hardness of Al surface after ablation in both ambient (Ar, O2). In the case of reactive environment (O2), the interplay among the deposition of laser energy and species of plasma of ambient gas enhances chemical reactivity, which causes the formation of oxides of aluminum (AlO, Al2O3) with high mechanical strength. That makes it useful in the field of process and aerospace industry as well as in surface engineering.

13.
J Microbiol Methods ; 187: 106276, 2021 08.
Article in English | MEDLINE | ID: mdl-34214601

ABSTRACT

We report here a mathematical framework for the quantitative interpretation of exponential bacterial growth measured with isothermal microcalorimetry. The method allows determination of many parameters that define the exponential growth phase. To automate the analysis, we also wrote a coding program, so that the approach could be embedded in a commercial setting. As an exemplar, we apply the method to a commercial probiotic product. The outcome was that we could identify characteristic parameters of growth (including rate constant and doubling time), and hence authenticate product quality, within 15 h. This compares favourably with the current 7-10 days required for conventional microbiological assessment (to allow release of product for bottling and marketing) via plating methods. The method would lend itself to growth analysis of single and mixed bacterial cultures.


Subject(s)
Bacteria/growth & development , Bacterial Load , Calorimetry/methods , Lacticaseibacillus rhamnosus/growth & development , Kinetics , Mathematical Concepts , Probiotics , Software
14.
Biomed Res Int ; 2021: 9916909, 2021.
Article in English | MEDLINE | ID: mdl-34327239

ABSTRACT

The fabrication of sensitive protein microarrays such as PCR used in DNA microarray is challenging due to lack of signal amplification. The development of microarrays is utilized to improve the sensitivity and limitations of detection towards primal cancer detection. The sensitivity is enhanced by the use of ZnO-nanorods and is investigated as a substrate which enhance the florescent signal to diagnose the hepatocellular carcinoma (HCC) at early stages. The substrate for deposition of ZnO-nanorods is prepared by the conventional chemical bath deposition method. The resultant highly dense ZnO-nanorods enhance the fluorescent signal 7.2 times as compared to the substrate without ZnO-nanorods. The microarray showed sensitivity of 1504.7 ng ml-1 and limit of detection of 0.1 pg ml-1 in wide dynamic range of 0.05 pg-10 µg ml-1 for alpha fetoprotein (AFP) detection in 10% human serum. This immunoassay was successfully applied for human serum samples to detect tumor marker with good recoveries. The ZnO-nanorod substrate is a simple protein microarray which showed a great promise for developing a low-cost, sensitive, and high-throughput protein assay platform for several applications in both fundamental research and clinical diagnosis.


Subject(s)
Microarray Analysis , Nanotubes/chemistry , Serum/chemistry , Zinc Oxide/chemistry , alpha-Fetoproteins/analysis , Fluorescence , Humans , Immunoassay , Limit of Detection , Nanotubes/ultrastructure , Reproducibility of Results , Spectrometry, X-Ray Emission , Surface Properties , Time Factors , X-Ray Diffraction
15.
Mater Sci Eng C Mater Biol Appl ; 117: 111296, 2020 Dec.
Article in English | MEDLINE | ID: mdl-32919657

ABSTRACT

A selective and cost-effective biosensor based on catalase immobilized antimonene quantum dots modified glassy carbon electrode (Cat@AMQDs-GCE) is designed for the first time to determine hydrogen peroxide (H2O2). Antimonene quantum dots (AMQDs) are synthesized by a single step method, characterized by various analytical techniques and applied to the electrochemical sensing of hydrogen peroxide. Catalase enzyme specific for H2O2 reduction is immobilized onto AMQDs to facilitate its detection by cyclic voltammetry and amperometry. Concentration, scan rate, pH, stability and selectivity are optimized. Linearity of Cat@AMQDs-GCE is determined as 0.989 with limit of detection as 4.4 µM. Amperometric measurements show recovery of 95 to 103.4% for H2O2 from human serum samples. Cat@AMQDs-GCE is electrochemically stable up to 30 cycles, reducing the cost of analysis. Cat@AMQDs-GCE shows good selectivity in presence of ascorbic acid, dopamine, leucine and glucose. Prepared electrode is also applied for the quantitative determination of H2O2 from ovarian cancer serum. CA 125 concentration is previously determined by Elecsys CA 125 II Assay. Results demonstrate that concentration of H2O2 increases with increasing levels of CA125 in serum.


Subject(s)
Biosensing Techniques , Ovarian Neoplasms , Quantum Dots , Catalase , Electrochemical Techniques , Electrodes , Female , Humans , Hydrogen Peroxide
16.
Asian J Neurosurg ; 14(1): 41-46, 2019.
Article in English | MEDLINE | ID: mdl-30937006

ABSTRACT

BACKGROUND: Meningiomas comprise 15%-20% of all primary intracranial tumors. They are generally benign tumors, and most patients are cured after surgery and remain free of recurrence. However, some tumors behave in an aggressive manner, and patients develop local recurrence or metastasis. Overall prognosis is good. PATIENTS AND METHODS: This is an 11-year retrospective study conducted in the Departments of Pathology and Neurosurgery at Sheri-I-Kashmir Institute of Medical Sciences, Kashmir, India. Besides the demographic profile, the parameters analyzed were location of tumor on imaging, histopathological subtype, and grade of tumor according to the 2007 WHO classification and recurrence at follow-up. RESULTS: A total of 254 patients were included in our study, of which 205 (80.7%) were brain meningiomas and 49 (19.3%) were spinal, with an overall female: male ratio of 2:1. Female: male ratio was more in spinal meningiomas, 15.3:1. Most of our patients were in the 4-6th decade of life with a mean age of 48 years (range: 5-73 years). Meningothelial meningioma was the most common histological type. Of ten patients who showed recurrence, seven cases showed only recurrence, but no progression to higher grade and three cases showed recurrence with progression by one WHO-grade. We also noticed that recurrence was higher in Simpson Grades II and III. CONCLUSION: Meningiomas are common in females and most of the meningiomas do well after surgery. The recurrence rate was 3.93% in our study and Simpson grade of tumor excision and histopathological grade contribute significantly to the recurrence of the tumor.

17.
Appl Opt ; 58(4): 1110-1120, 2019 Feb 01.
Article in English | MEDLINE | ID: mdl-30874160

ABSTRACT

The effect of magnetic field on laser-induced breakdown spectroscopy of aluminum (Al) plasma has been investigated. Al targets were exposed to Nd:YAG laser pulses at different irradiances ranging from 1 GWcm-2 to 2.7 GWcm-2, under argon (Ar) and neon (Ne) environments at various pressures ranging from 5 torr to 760 torr and at different time delays from 0.42 µs to 9.58 µs. All spectroscopy measurements were performed in the absence and presence of transverse magnetic field of strength 0.9 tesla. When laser irradiance is increased by keeping the pressure (10 torr) and time delay constant (1.25 µs), both excitation temperature (Te) and number density (ne) increase up to certain values. The same trend is observed for Te and ne when the ambient gas pressure of Ar and Ne is increased by keeping the irradiance (1.7 GWcm-2) and time delay constant. At higher irradiances and pressures, saturation is observed, which is attributed to the self-regulating regime of plasma. In the case of time delay, both electron temperature and number density decay exponentially, which is according to the adiabatic expansion model. It is revealed that emission intensity and electron temperature are higher in the presence of magnetic field as compared to the field-free case, which is attributed to magnetic confinement, as well as the joule heating effect. Plasma plume confinement is confirmed by analytical evaluation factor ß. ß is an analytical factor that is the ratio of plasma pressure to magnetic pressure, i.e., ß=Plasma pressureMagnetic pressure. It confirms the validity of magnetic field confinement if ß is less than 1. As the evaluated values of ß are less than 1 for all cases, they confirm the validity of magnetic confinement.

18.
Int J Cardiol ; 219: 326-30, 2016 Sep 15.
Article in English | MEDLINE | ID: mdl-27344134

ABSTRACT

BACKGROUND: Copeptin is a novel biomarker of potential diagnostic and prognostic value in patients with ST-elevation myocardial infarction (STEMI). This study was conducted to investigate the relationship between plasma copeptin levels at admission and final infarct size in STEMI patients. MATERIALS AND METHODS: This observational study was conducted in Sher-i-Kashmir Institute of Medical sciences, Srinagar, for a period of 1year. 60 patients with STEMI admitted within 24h of symptom onset were included in the study. Plasma copeptin concentrations were determined by ELISA from blood samples drawn at the time of admission. Infarct size was estimated on cardiac MRI after 5-14days of admission, in successfully reperfused patients. Correlations between plasma copeptin levels, infarct size and various clinico-hemodynamic variables were studied. RESULTS: Plasma copeptin concentrations showed a significant positive correlation with MRI determined infarct size (r=0.957; p≤0.0001). Copeptin levels were significantly higher in patients with anterior wall infarction (p≤0.0001), longer symptom duration (p=0.018), advanced Killip class (p≤0.0001), higher body mass index (p=0.019) and extensive coronary artery disease (p≤0.0001). On multivariate analysis, copeptin levels at admission independently predicted final infarct size, irrespective of the clinico-hemodynamic profile of patients or mode of reperfusion (p≤0.0001). The only independent predictor of copeptin level was symptom duration (p=0.018). CONCLUSION: Copeptin level at admission predicts final infarct size in STEMI patients. Further evidence is however needed before implementation of this biomarker into routine clinical practice.


Subject(s)
Glycopeptides/blood , Patient Admission/trends , ST Elevation Myocardial Infarction/blood , ST Elevation Myocardial Infarction/diagnostic imaging , Adult , Aged , Aged, 80 and over , Biomarkers/blood , Cohort Studies , Female , Humans , Magnetic Resonance Imaging, Cine/methods , Male , Middle Aged , Predictive Value of Tests
19.
Lasers Med Sci ; 30(9): 2233-8, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26246054

ABSTRACT

Laser-induced breakdown spectroscopy (LIBS) analysis of human deciduous teeth has been performed by employing Nd:YAG laser (1064 nm, 10 ns) for the evaluation of plasma parameters as well as elemental analysis. The plasma parameters, i.e., electron temperature and electron number density of laser-induced teeth plasma at various fluencies, have been evaluated. Both parameters show an increasing trend up to a certain value of laser fluence, i.e., 2.6 J/cm(2). With further increase in laser fluence up to a value of 3.9 J/cm(2), a decreasing trend is observed which is due to shielding effect. With further increase in laser fluence up to a maximum value of 10.5 J/cm(2), the insignificant changes in plasma parameters are observed which are attributed to saturation phenomenon governed by self-regulating regime. Emission spectroscopy results exhibit that laser fluence is the controlling factor for both plasma parameters. The elemental analysis was also performed at constant laser fluence of 2.6 J/cm(2) by evaluating the variation in detected elemental concentration of Ca, Fe, Sr, Zn, and Pb in three different parts of human teeth, i.e., enamel, dentine, and cementum. The lower concentration of Ca as compared to the standard values of CaCO3 (self-fabricated pellet) reveals that enamel is the most deciduous part of the human teeth. However, at the same time, it is also observed that the highest concentration of micro minerals is also found in enamel, then in dentine, and lowest in cementum. Carious or unhealthy tooth is identified by enhanced concentration of micro minerals (Pb, Sr, Zn, and Fe). The highest concentration of micro minerals as compared to other parts of teeth (dentine and root cementum) and lower concentration of Ca as compared to standard CaCO3 pellet in enamel confirm that enamel is the most deciduous part of the teeth.


Subject(s)
Lasers, Solid-State , Spectrum Analysis , Tooth, Deciduous/chemistry , Tooth, Deciduous/radiation effects , Humans
20.
Int J Gynecol Cancer ; 24(7): 1262-7, 2014 Sep.
Article in English | MEDLINE | ID: mdl-25078343

ABSTRACT

OBJECTIVES: Type II endometrial carcinomas-uterine carcinosarcomas or uterine malignant mesodermal mixed tumors (UMMMTs), clear cell carcinomas (UCCs), and uterine serous carcinomas (USCs)-are aggressive malignancies that present with advanced disease and have high mortality rates. PIK3CA mutations are commonly found in endometrial cancers. The objective of the study was to characterize molecular alterations in the PIK3CA gene in these tumors. METHODS: A total of 84 cases (20 UMMMTs, 18 UCCs, and 46 USCs) were selected from the surgical pathology files of Weill Cornell Medical College and Johns Hopkins Hospital. The diagnoses were confirmed by gynecologic pathologists (L.H.E. and A.Y.). DNA was extracted from paraffin-embedded tissue. Polymerase chain reaction was performed for mutational analysis. All the studies were performed in accordance with approved Institutional Review Board protocols. RESULTS: Mutations in the PIK3CA gene were identified in 3 (15%) of 20 UMMMT, 3 (16.7%) of 18 UCC, and 10 (21.7%) of 46 USC cases. We report novel mutations in PIK3CA in uterine carcinosarcoma. CONCLUSIONS: A significant percentage of UMMMTs, UCCs, and USCs have mutations in PIK3CA. Further investigation is needed to develop targeted therapies for these aggressive uterine cancers.


Subject(s)
Adenocarcinoma, Clear Cell/genetics , Carcinosarcoma/genetics , Cystadenocarcinoma, Serous/genetics , Mutation , Phosphatidylinositol 3-Kinases/genetics , Uterine Neoplasms/genetics , Adenocarcinoma, Clear Cell/epidemiology , Adenocarcinoma, Clear Cell/pathology , Amino Acid Substitution , Carcinosarcoma/epidemiology , Carcinosarcoma/pathology , Class I Phosphatidylinositol 3-Kinases , Cystadenocarcinoma, Serous/epidemiology , Cystadenocarcinoma, Serous/pathology , DNA Mutational Analysis , Female , Humans , Polymorphism, Single Nucleotide , Sequence Deletion , Uterine Neoplasms/epidemiology , Uterine Neoplasms/pathology
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