Histopathological study of thyroid lesions and correlation with ultrasonography and thyroid profile in western zone of Rajasthan, India

Background: To evaluate the different patterns of thyroid lesions in surgically resected specimens and biopsies received at department of pathology and correlate the various histo-morphological features with respect to clinical findings, USG and thyroid profile findings.Methods: Total 100 cases of partial or complete thyroidectomy were studied. A detailed clinical examination with USG examination and assessment of thyroid function test were carried out preoperatively.Results: The highest incidences (51%) of thyroid enlargements were found in age group of 21-40 years with females predominated (77%), ratio being 3.34:1. Out of total 100 cases, 28 were neoplastic and 72 were non-neoplastic. Thyroid function test was carried out of all 100 cases and out of them 81 were euthyroid. Most common clinical symptom in the patients of thyroid lesions was swelling in the neck which was present in all cases. Multinodular goiter was the most common radiological finding seen in 55% cases. Out of 55 cases of MNG one case turned out to be malignant after histopathological examination. USG diagnosed 10 cases were malignant, out of them 1 case turned out to be benign after histopathological examination.Conclusions: Taking into consideration histopathology report as a gold standard, correlation of USG finding with histopathology finding showed 90% sensitivity, 98.8% specificity with 90% positive predictive value

Compatibilisation of 1D/2D graphitic nanomaterials and poly(propylene) via non-covalent functionalisation with poly(acrylate)s

1D and 2D graphitic materials (carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs)) are of great interest due to their extraordinary electrical, thermal, mechanical and optical properties rarely found in bulk materials. The transfer of such properties to polymers has been limited and the development of scalable, cost-effective, multi-functional composite materials not fully realised. Polymers filled with 1D and 2D graphitic nanomaterials have uses in a wide range of applications and industries ranging from aerospace and automotive to personal care and high-tech products. Growing global economic development has sharply increased the world’s energy needs and in particular, our energy storage needs. In addition, they have potential applications in electronics, sensors and energy conversion. Another application in the area of personal care has shown that CNT-polymer composites can be used to speed up the process of bone-regeneration by being used as tissue scaffold materials. An application of interest is to use graphitic nanomaterials to produce composites with high mechanical performance (stiffness and strength) with low filler quantity providing innovative light-weighting solutions. Further potential applications of 1D and 2D graphitic nanomaterials include; touch screens, capacitors, spintronic devices, fuel cells, conductive films, high frequency circuits and flexible electronics. The development of such innovative materials requires the nanofiller to be homogenously dispersed within the polymer matrix, e.g. poly(propylene)(PP). The formation of an interconnected filler network structure at a low percolation threshold will result in the enhancement of electrical and thermal conductivity. In addition, efficient interfacial adhesion and stress transfer between filler and polymer results in improved mechanical strength and stiffness. However, poor compatibility between filler and the PP matrix prevents efficient homogenous dispersion and network formation. To address this major technical challenge, the use of a polymer compatibiliser which non-covalently functionalised graphitic nanomaterials was explored. By way of example, poly(lauryl acrylate) P[LA] was selected based upon its known compatibility with PP and it was proposed that it would also non-covalently functionalise such fillers via CH-π wrapping. P[LA] was synthesised using controlled living radical polymerisation methods and was shown to both be thermally stable for extrusion and physisorbed onto the surface of MWCNTs. For composites of PP, P[LA] and either MWCNTs or GNPs evidence was obtained confirming that P[LA] improved filler dispersion however, the most notable observation was a significant reduction in Tg of PP which was associated with P[LA] plasticising PP. Further polymer compatibilisers based on copolymers (statistical and block) of P[LA] and poly(2-phenyl ethyl acrylate) P[2PEA] where also synthesised and their potential to non-covalently functionalise CNTs and GNPs via both CH-π wrapping and π-π stacking examined. A range of characterisation techniques were employed to thoroughly understand the behaviour of these compatibilisers when added to composites of MWCNTs/GNPs and PP. Evidence for π-π stacking of P[2PEA] onto the surface of both graphitic fillers was observed from extensive electron microscopy observations. The potential of P[LA-co-2PEA] block copolymers as compatibilisers for 1D and 2D graphitic materials and PP was proven. The use of poly(acrylate)s as compatibilisers to assist the dispersion of 1D and 2D graphitic nanofillers in a PP has proven to be a concept with limited potential to alter the mechanical, electrical and thermal properties of polymers. The excellent thermal stability demonstrated by poly(acrylate)s for the purpose of melt blending with PP provides scope for further work through alternative functionalisation strategies e.g. covalent functionalisation. Throughout the project, the discussion has centred around the use of P[LA] and P[2PEA] due their potential to adsorb onto surface of 1D and 2D graphitic fillers and promote their dispersion in a PP matrix however, further work should investigate a range of poly(acrylate)s with various structures, chemistries, molecular weights and dispersities. For example, the use poly(acrylate)s with longer side chains such as poly(octadecyl acrylate) or poly(acrylate)s containing aromatic side chains with a greater number of benzene rings such as pyrene, for example pyrene acrylate. It is evident that the viscosity of the compatibilising polymer influences the extent of dispersion of the compatibiliser in the PP and matrix and therefore, it would be interesting to investigate if there is a correlation between the viscosity of the polymer compatibiliser and the extent of its dispersion in the PP matrix. GNPs with a greater aspect ratio are predicted to achieve percolation at lower loadings, increase electrical and thermal conductivity as well as improve the mechanical properties. Additionally, it would be interesting to explore what GNP quantity is required to achieve electrical and rheological percolation with the same type of GNPs and correlate those findings with graphenes with different aspect ratios to understand the role of flake dimensions. It is clear, P[LA] is not particularly successful in compatibilising the GNPs used in this study. In addition, it would useful to conduct dynamic cross-polarized optical microscopy and WAXS/SAXS scattering experiments during heating and cooling to investigate transcrystallinity phenomena at the interface between GNPs and the PP matrix

On the phase affinity of multi-walled carbon nanotubes in PMMA:LDPE immiscible polymer blends.

The localization of multi-walled carbon nanotubes (MWCNTs) in PMMA/LDPE blends was studied. Theoretical predictions suggested their preferential localization in the PMMA. Conversely, experimental work revealed that non-functionalized MWCNTs located in the LDPE, polymer first to melt. When the extrusion time is not long enough, the MWCNTs do not have the chance to further migrate to the thermodynamically most favourable phase. The evolution of a double percolation determined if the composite became semi-conductive. In that sense, two blends with PMMA to LDPE ratios of 80:20 and 20:80 containing 2 wt.% MWCNTs had electrical resistivity values in the order of 105 and 1012 Ω cm, respectively. Only in the 80:20 blend was the “effective” MWCNT concentration high enough such that electrical percolation was attained. However, bulk rheological properties were controlled by the major phase. Thus, 2 wt.% MWCNTs had a notable effect on the linear viscoelasticity at low frequencies of the 20:80 blend

Experimental investigation on interply friction properties of thermoset prepreg systems

A comprehensive novel investigation into the characterisation of interply friction behaviour of thermoset prepregs for high-volume manufacturing was conducted. High interply slipping rate and normal pressure typically used for high-volume manufacturing present challenges when preforming carbon fibre reinforced plastics. The study involved multiple reinforcement architectures (woven and unidirectional with the same rapid-cure resin system) which were characterised using a bespoke interply friction test rig used to simulate processing conditions representative to press forming and double diaphragm forming. Under prescribed conditions, woven and unidirectional prepregs exhibit significantly different frictional behaviour. Results demonstrated the unidirectional material obeys a hydrodynamic lubrication mode. For the woven material, a rate-dependent friction behaviour was found at low normal pressure. At higher normal pressure however, the woven material exhibited a friction behaviour similar to that of a dry reinforcement and significant tow displacement was observed. Post-characterisation analysis of test-specimens showed significant resin migration towards the outer edges of the plies, leaving a relatively resin-starved contact interface. The findings generate new knowledge on interply friction properties of thermoset prepreg for high-volume manufacturing applications, yet reveal a lack of understanding of the influence of tow tensions as well as the pre-impregnation level for a range of processing conditions. </jats:p

Isothermal and non-isothermal crystallization kinetics of composites of poly(propylene) and MWCNTs

The isothermal and non-isothermal crystallization behaviour of composites of a poly(propylene) (PP) and multi-walled carbon nanotubes (MWCNTs) were investigated using Differential Scanning Calorimetry (DSC). An Avrami analysis was used to study the isothermal crystallization kinetics of unfilled PP and composites of PP with MWCNT loadings up to 2 (w/w). The value of the Avrami exponent (n) was greater than 2 for all samples, confirming the primary stage of crystal growth is a three-dimensional phenomenon. The activation energy (ΔE), determined using an Arrhenius type expression, for the isothermal crystallization of PP increased from 87 kJ for unfilled PP to 228 kJ on incorporation of 2 (w/w) MWCNTs to PP. An attempt was made to model the non-isothermal crystallization kinetics of composites of PP and MWCNTs using a range of mathematical models, including the Jeziorny extended Avrami equation, Ozawa equation, Cazé and Chuah average Avrami exponents, and a combined Avrami/Ozawa approach. The Jeziorny extended Avrami approach confirmed that the non-isothermal crystallization of MWCNT filled PP is clearly a two-stage process. Fitting of the Ozawa model was shown to be not valid and both the Cazé and Chuah average Avrami approaches were ineffective as neither took in to account the effects of secondary crystallization. Only the combined Avrami/Ozawa method successfully modelled the two-stage crystallization of composites of PP and MWCNTs. The activation energy (ΔE) for the non-isothermal crystallization of PP on addition of MWCNTs increased with increasing MWCNT content, up to as high as 726 kJ

Experimental investigation on interply friction properties of thermoset prepreg systems

A comprehensive novel investigation into the characterisation of interply friction behaviour of thermoset prepregs for high-volume manufacturing (HVM) was conducted. High interply slipping rate and normal pressure typically used for HVM present challenges when preforming carbon fibre reinforced plastics (CFRP). The study involved multiple reinforcement architectures (woven and unidirectional (UD) with the same rapid-cure resin system) which were characterised using a bespoke interply friction test rig used to simulate processing conditions representative to press forming and double diaphragm forming. Under prescribed conditions, woven and UD prepregs exhibit significantly different frictional behaviour. Results demonstrated the UD material obeys a hydrodynamic lubrication mode. For the woven material, a rate-dependent friction behaviour was found at low normal pressure. At higher normal pressure however, the woven material exhibited a friction behaviour similar to that of a dry reinforcement and significant tow displacement was observed. Post-characterisation analysis of test-specimens showed significant resin migration towards the outer edges of the plies, leaving a relatively resin-starved contact interface. The findings generate new knowledge on interply friction properties of thermoset prepreg for HVM applications, yet reveal a lack of understanding of the influence of tow tensions as well as the pre-impregnation level for a range of processing conditions

Comprehensive analysis of temporal alterations in cellular proteome of bacillus subtilis under curcumin treatment

Curcumin is a natural dietary compound with antimicrobial activity against various gram positive and negative bacteria. This study aims to investigate the proteome level alterations in Bacillus subtilis due to curcumin treatment and identification of its molecular/cellular targets to understand the mechanism of action. We have performed a comprehensive proteomic analysis of B. subtilis AH75 strain at different time intervals of curcumin treatment (20, 60 and 120 min after the drug exposure, three replicates) to compare the protein expression profiles using two complementary quantitative proteomic techniques, 2D-DIGE and iTRAQ. To the best of our knowledge, this is the first comprehensive longitudinal investigation describing the effect of curcumin treatment on B. subtilis proteome. The proteomics analysis revealed several interesting targets such UDP-N-acetylglucosamine 1-carboxyvinyltransferase 1, putative septation protein SpoVG and ATP-dependent Clp protease proteolytic subunit. Further, in silico pathway analysis using DAVID and KOBAS has revealed modulation of pathways related to the fatty acid metabolism and cell wall synthesis, which are crucial for cell viability. Our findings revealed that curcumin treatment lead to inhibition of the cell wall and fatty acid synthesis in addition to differential expression of many crucial proteins involved in modulation of bacterial metabolism. Findings obtained from proteomics analysis were further validated using 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) assay for respiratory activity, resazurin assay for metabolic activity and membrane integrity assay by potassium and inorganic phosphate leakage measurement. The gene expression analysis of selected cell wall biosynthesis enzymes has strengthened the proteomics findings and indicated the major effect of curcumin on cell division

Functionalisation of MWCNTs with poly(lauryl acrylate) polymerised by Cu(0)-mediated and RAFT methods

Poly(lauryl acrylate) P[LA] of various molar masses were prepared via reversible addition–fragmentation chain transfer (RAFT) polymerisation and Cu(0)-mediated radical polymerisation, for the purpose of improving the dispersion and interfacial adhesion of MWCNTs with polymers such as isotactic poly(propylene) (iPP). Lauryl acrylate (LA) was polymerised via RAFT to high conversion (95%), furnished polymers in good agreement with theoretical Mn with dispersity increasing with increasing Mn. LA polymerised via the Cu(0)-mediated method to full conversion (>98%), gave polymers in good agreement with theoretical Mn and low dispersity (Đ ≈ 1.2) for lower molar mass polymers. Low molar mass tailing was also observed for P[LA] via Cu(0)-mediated polymerisation for higher molar mass polymers. Thermogravimetric analysis (TGA) of P[LA] via RAFT showed an onset of degradation occurred at ≈340–350 °C, however, this decreased to ≈250–260 °C for lower molar mass polymers. TGA of the RAFT agent revealed an onset of degradation of ≈200–250 °C. Free radicals generated from thermal degradation of end groups did not influence the thermal stability of the P[LA] backbone and ‘unzipping’ commonly seen with methacrylates was not observed. TGA analysis of P[LA] via the Cu(0)-mediated method revealed a similar degradation profile to that of P[LA] via RAFT. The thermal stability of P[LA] is sufficient to allow for melt processing with iPP. P[LA] via RAFT mixed with MWCNTs showed an adsorption of ≈10–25 wt% P[LA] on to the MWCNTs. The onset of thermal degradation of the P[LA] remained unchanged after adsorption on to the MWCNTs. P[LA] via the Cu(0)-mediated method adsorbed up to 85 wt% and an increase in thermal stability of ≈50 °C was recorded. Increasing P[LA] and MWCNT concentration independently also resulted in an increase in the level of adsorption, possibility due to increased CH–π interaction. The difference in thermal stability could possibly be due to heat transfer from the P[LA] to the MWCNTs, resulting in delayed pyrolysis of P[LA]. Size exclusion chromatography (SEC) and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) of P[LA] after heating to 200 °C for 30 min in air showed loss of end groups but, the P[LA] backbone remained preserved for both polymer types. Evidence from transmission electron micrographs (TEM) shows the P[LA] adsorbing onto the MWCNT surface. Melt processing composites of P[LA] via Cu(0)-mediated with MWCNTs and iPP was possible as the P[LA] was thermally stable during the both extrusion and in the TGA when studied post melt mixing

Plasticisation and compatibilisation of poly(propylene) with poly(lauryl acrylate) surface modified MWCNTs

Poly(lauryl acrylate) P[LA] synthesised using Cu(0)-mediated polymerisation was used to non-covalently functionalise multi-walled carbon nanotubes (MWCNTs) achieved via combined CH-π interactions and physical wrapping. The inclusion of P[LA] competed with the attractive van der Waals forces between MWCNTs altering interfacial interactions between neighbouring CNTs and, assisted their dispersion and distribution in a poly(propylene) (PP) matrix, confirmed from SEM/HR-TEM imaging and oscillatory rheology measurements. A rheological percolation threshold measured for composites of unmodified MWCNTs and PP at ∼0.5 wt% was shifted to lower MWCNT concentrations (∼0.25 wt%) for P[LA] functionalised MWCNTs. Addition of P[LA] also reduced the nucleating effect of MWCNTs for PP as a coating of P[LA] on the nanotube surfaces hindered trans-crystallisation of the PP. Evidence from static and dynamic mechanical measurements confirmed the P[LA] plasticised PP as both an increase in ductility and a decrease in the glass transition temperature (Tg) of PP of up to 25 °C was obtained. Addition of unmodified MWCNTs to PP resulted in an increase in the DC electrical conductivity of PP of 15 orders of magnitude, from 10−14 S/m to 101 S/m for a MWCNT loading of 5 wt%. Non-covalent functionalisation of MWCNTs utilising P[LA] only degraded electrical conductivity by about 2 orders of magnitude across the composition range

Histopathological study of thyroid lesions and correlation with ultrasonography and thyroid profile in western zone of Rajasthan, India

Background: To evaluate the different patterns of thyroid lesions in surgically resected specimens and biopsies received at department of pathology and correlate the various histo-morphological features with respect to clinical findings, USG and thyroid profile findings.Methods: Total 100 cases of partial or complete thyroidectomy were studied. A detailed clinical examination with USG examination and assessment of thyroid function test were carried out preoperatively.Results: The highest incidences (51%) of thyroid enlargements were found in age group of 21-40 years with females predominated (77%), ratio being 3.34:1. Out of total 100 cases, 28 were neoplastic and 72 were non-neoplastic. Thyroid function test was carried out of all 100 cases and out of them 81 were euthyroid. Most common clinical symptom in the patients of thyroid lesions was swelling in the neck which was present in all cases. Multinodular goiter was the most common radiological finding seen in 55% cases. Out of 55 cases of MNG one case turned out to be malignant after histopathological examination. USG diagnosed 10 cases were malignant, out of them 1 case turned out to be benign after histopathological examination.Conclusions: Taking into consideration histopathology report as a gold standard, correlation of USG finding with histopathology finding showed 90% sensitivity, 98.8% specificity with 90% positive predictive value