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The photothermal conversion efficiency of gold different nanoparticles (GNPs) in different concentrations (1.25–20 µg/mL) and at different irradiation intensities of near-infrared (NIR) broadband and NIR laser irradiation is evaluated. Results show that for a concentration of 20.0 µg/mL, 40 nm gold nanospheres, 25 × 47 nm gold nanorods (GNRs), and 10 × 41 nm GNRs show a 4–110% higher photothermal conversion efficiency under NIR broadband irradiation than under NIR laser irradiation. Broadband irradiation seems suitable to attain higher efficiencies for the nanoparticles whose absorption wavelength is different from the irradiation wavelength. Lower concentrations (1.25–5 µg/mL) of such nanoparticles show 2–3 times higher efficiency under NIR broadband irradiation. For GNRs of sizes 10 × 38 nm and 10 × 41 nm, the different concentrations show almost equal efficiencies for NIR laser and broadband irradiation. On increasing the irradiation power from 0.3 to 0.5 W, for 10 × 41 nm GNRs in the concentration range of 2.5–20.0 µg/mL, NIR laser irradiation results in 5–32% higher efficiencies, while NIR broadband irradiation leads to a 6–11% increase in efficiency. Under NIR laser irradiation, the photothermal conversion efficiency increases with an increase in optical power. The findings will facilitate the selection of nanoparticle concentrations, irradiation source, and irradiation power for a variety of plasmonic photothermal applications.

Aim This paper aims to investigate the photo-thermally enhanced antimicrobial efficacy of triangular silver nanoplates for a broad range of harmful pathogens viz., Gram-negative bacteria (Escherichia coli), Gram-positive bacteria (Staphylococcus aureus), and fungus (Candida albicans). Methods and Results Triangular silver nanoplates were synthesized using the chemical method and were characterized for optical absorption, size and morphology, surface charge and concentration via UV–Vis spectroscopy, transmission electron microscopy, zeta potential analysis and inductively coupled plasma mass spectrometry, respectively. Furthermore, the photo-thermally enhanced antimicrobial efficacy of the triangular silver nanoplates (10 μg/ml concentration) was evaluated on broadband near-infrared irradiation. The photothermal response shows that for the fixed concentration of silver nanoplates, the smaller-sized nanoplates (~52 nm) lead to higher temperature rise than larger-sized nanoplates (~68 nm). It is demonstrated that within a short exposure duration of 15 min, the photothermal activation of silver nanoplates led to ~5 log10 CFU/ml reduction for E. coli and C. albicans, and ~7 log10 CFU/ml reduction for S. aureus from a considerably high initial load of 5 × 108 CFU/ml. Conclusions The present study demonstrates that photo-thermally enhanced triangular silver nanoplates possess much stronger antimicrobial efficacy over a short exposure duration of few minutes and exhibits the applicability for a broad range of pathogens. Significance and Impact of Study The study is highly significant and explains the eradication of broad-spectrum of microbial pathogens by photo-thermally enhanced silver nanoplates in short exposure duration with low nanoparticle concentration, which is useful for diverse antibacterial and antifungal applications.

Correction of Class II malocclusion by distalization of maxillary molars with intraoral appliances is a non-extraction treatment approach, which has been described as an alternative to Head Gear. From the past few years, the procedures have undergone rectification to achieve treatment objective more precisely. This has been made possible by a better understanding of bone physiology, tooth movement, biomechanics and newer biomaterials. Nowadays newer distalizing appliances, like the Jones Jig, Lokar distalizer and Carrière distalizer, have been developed which have compact designs and cause minimal discomfort to the patient. Refinement in these appliances is concentrated mainly on achieving bodily movement of the molar rather than simple tipping. These appliances are also operator friendly as these are easy to insert and remove. Researchers have focused on the simplicity and efficiency of these intraarch devices. which improves the continuity and constancy of forces. Oral hygiene is easier to maintain and the need for patient compliance is eliminated.

This paper synthesizes triazole-attached 2-aminofluorene-based organosilane for sensing Fe3+ ion using UV-Vis and fluorescence. Probe 6a's inhibitory effect on the leishmania protein was studied. DFT explained 6a's complexation with Fe3+ ion.

Orthodontic wires are integral part of fixed mechanotherapy in orthodontics which are used to facilitate tooth movement. A wide range of materials available that are used to manufacture orthodontic archwires. Selection of suitable wire material increase patient comfort, efficiency of orthodontic mechanics and reduce chair side time. Nowadays esthetic wire materials are available that can be used in esthetically conscious patients. This article discusses the changing trend in wire materials.

Orthodontic developments, especially during the last few years have been accompanied by a significant increase in the esthetic demands of the patients. As the demand for esthetic treatments is increasing, more people are seeking alternatives to fixed orthodontic appliances. Clear aligners provide an excellent solution as compared to fixed orthodontic appliances in terms of esthetics and comfort to the patient. In 1998, Align Technology (Santa Clara, Calif, USA) introduced Invisalign, a series of removable polyurethane aligners, as an esthetic alternative to fixed orthodontic appliances

The aim of this review article is to understand management of any emergency arising to the orthodontic patients during treatment and also management during corona virus pandemic. although there is no actual emergency, only few cases require immediate attention. Different commonly occurring problems are discussed along with analysis of different management methods. Any emergency relating to dental problems can also be evaluated using a social networking site (WhatsApp) or instructions given verbally as a mode of contacting patients and evaluating their issues especially during covid-19 scenario.

Class II malocclusion is the condition in which the mandibular first molars occlude distal to the normal relationship with the maxillary first molar. The etiology of class II malocclusion varied between skeletal, soft tissues, dental factors and habits. Skeletal class II could be because of protrusion of maxilla, retrusion of mandible and combination of both. The treatment modalities of any skeletal problem include growth modification, dental camouflage and orthognathic surgery. This article elaborates the etiology, clinical features, treatment objectives, orthodontic corrections, retention for class II division 2 maloclussion.

Arch expansion is a method of gaining space. An apparently complex yet relatively simple procedure in orthodontics is Palatal expansion. The correction of transverse maxillary deficiency can be an important component of an orthodontic treatment plan. Rapid Maxillary expansion (RME) is a skeletal type of expansion that involves the separation of the mid-palatal suture and movement of the maxillary shelves away from each other.RME effects the maxillary complex, palatal vaults, maxillary anterior and posterior teeth, adjacent periodontal structures to bring about an expansion in the maxillary arch. The majority of dental transverse measurements changed significantly as a result of RME. This review article provides detailed information about rapid maxillary expansion and the appliances used commonly for RME.

Oral habits are learned patterns of muscle contraction and have a very complex nature. They are associated with anger, hunger, sleep, tooth eruption and fear. Basicallya habit is a routine of behavior that is repeated regularly and tends to occur unconsciously. Habits are one of the major etiologic factors which will leads to malformation in dento-facial structures. Habits are the most frequent cause of these malformations mostly seen in the early childhood and mixed dentition stages.The oral bad habits that cause malocclussion problems include:Thumb sucking, it is a normal habit for babies, but causes serious orthodontic problems if it continues long after the eruption of permanent teeth. Prolonged thumb sucking can create crowded, crooked teeth, or bite problems and speech problems. Lip-biting or fingernail biting, both habits can shift the teeth out of alignment. Tongue thrusting, some children thrust their tongue forward,pressing it against the lips with a force that can result in teeth malocclusions such as ‘open bite’ or teeth protrusion (overjet). Modern orthodontics are usually able to treat most teeth malocclusions successfully, but prevention can help the family to avoid the large cost of orthodontic treatment.

Plasmonic photothermal therapy involves irradiation of a nanoparticle-embedded tumor, using near-infrared radiation, for its treatment. For a nanoparticle type, the absorption of incident radiation is governed by the nanoparticle dose (concentration of nanoparticles) and the type of tumor embedded with the nanoparticles. In this article, the optical characteristics (spectral absorption cross section, plasmonic wavelength and full-width half maxima) are computed, considering gold nanorod (GNR) doses of 0.02–1.0 mg/ml, for various tumor types i.e., colorectal, breast, brain and ameloblastoma. Also, the spatial distribution of nanoparticles within the tumor is accounted for. The results show that on increasing the GNR dose from 0.02 to 1.0 mg/ml, the peak absorption cross section increases by 26–28 times, whereas the plasmonic wavelength red-shifts by 8–13 nm and full-width half maxima increases by 68–71%. Depending on the spatial distribution of GNRs within the breast tumor, the optical absorption cross section increases by 45% and 94% for GNRs doses of 0.5 mg/ml and 1.0 mg/ml. These discussed results are of clinical significance for the prior estimation of nanoparticle dose-dependent optical characteristics for a tumor type. Based on these, suitable irradiation sources and parameters may be chosen for plasmonic photothermal therapy.

This paper presents the singularity analysis of a 7-degrees of freedom (DOF) hybrid manipulator consisting of a closed-loop within it. From the past studies, it is well-known that the kinematic singularities play a significant role in the design and control of robotic manipulators. Kinematic singularities pose two-fold effects – first, they can induce the loss of one or more DOF of the manipulator and cause infinite joint rates at that particular joint, and second, they help to determine the trajectory or zone with high mechanical advantage. In current work, a 7-DOF hybrid manipulator is considered which is being developed at Council Of Scientific And Industrial Research–Central Scientific Instruments Organisation (CSIR–CSIO) Chandigarh to assist a surgeon during a medical-surgical task. To emulate the natural motion of a surgeon, the challenging configuration with redundant DOF is utilized. Jacobian has been computed analytically and analyzed at each instantaneous configuration with the evaluation of manipulability. Effect of a closed loop in the hybrid configurations is focused at, and utilizing the contour plots, good and worst working zones are identified in the workspace of the manipulator. The verification and validation of best and worst manipulability points (singularities) are done with the help of genetic algorithms, to determine locally and globally optimal configurations. Finally, on the basis of the singularity analysis, the present work concludes with few guidelines to the surgeon about the best and worst working zones for surgical tasks.

Plasmonic interaction of nanoparticles located in close proximity, embedded in breast tissue, is simulated for estimating the optical characteristics like optical absorption cross-section, plasmonic wavelength as well as full-width half maxima (FWHM). The computations are done for the monomers, homodimers, and heterodimers of spherical and rod-shaped gold nanoparticles considering various interparticle spacings for gold nanospheres and the interparticle spacing as well as the orientation for gold nanorods (GNRs). The results indicate that for the spherical dimer, with the change in interparticle spacing from 1 to 20 nm, the peak absorption cross-section decreases by 43%. Whereas for the GNRs, the absorption cross-section increases/decreases, within 9–18%, depending on the homodimer or heterodimer configuration. Furthermore, secondary peaks for the absorption cross-section are obtained within wavelengths of 630–940 nm due to antibonding modes for GNR heterodimers. For GNR heterodimer located end-to-end, this secondary peak for the absorption cross-section appears at 780 nm irrespective of interparticle spacing within 1–5 nm. The absorption coefficient is considerably dependent on the configuration and proximity of GNRs located within the tissue. While FWHM is not significantly influenced by GNRs configuration and interparticle spacing. For interparticle spacing from 1 to 20 nm, the plasmonic wavelength shifts by 38 nm for the spherical dimer and by 35–86 nm for various GNR dimers. The findings of this study are useful for plasmonic photothermal therapeutics as the heat generation is governed by the resulting absorption cross-section due to plasmonic coupling of the closely spaced and different orientations of the nanoparticles.

Aim: Gold nanoblackbodies (AuNBs)-mediated plasmonic photothermal cancer therapy was investigated through melanoma-bearing mice. Materials & methods: Polydopamine-coated Au nanoclusters were synthesized, termed AuNBs and PEGylated AuNBs (AuNBs-PEG). The photothermal response of AuNBs-PEG was evaluated upon low-intensity broadband near-infrared irradiation (785/62 nm; 0.9 Wcm-2), and cytotoxicity was assessed on B16-F10 cells. Further, the therapeutic potential of intravenously administered AuNBs-PEG was evaluated on B16-F10 melanoma in C57BL/6 mice. Results: AuNBs-PEG showed an excellent photothermal response (photothermal conversion efficiency of 60.3%), robust photothermal stability and no cytotoxicity. For AuNB-mediated plasmonic photothermal therapy, an average temperature of 63°C was attained within 5 min of irradiation, and tumors were eradicated. Conclusion: AuNBs-PEG are promising photothermal agents for treating melanoma through low-intensity broadband near-infrared irradiation.

In this study, the temporal dynamic changes in optical properties of gold nanorods (GNR) embedded tumor phantom, during photothermal interaction, are reported for plasmonic photothermal therapeutics. Tumor mimicking bilayer phantoms were prepared by using 1% agarose incorporated with 0.1% coffee powder, 0.3% intralipid solution as epidermis layer; 3% intralipid solution and 0.3% human hemoglobin (Hb) powder as dermis layer. On incorporating GNRs of concentrations 10, 20, and 40 μg/ml within the phantom, the absorption coefficients increases 4-8 times, while there is minimal change in the reduced scattering coefficients. Further the absorption coefficient increased by ~8% with the incorporation of GNRs of concentration 40 μg/ml, while no considerable dynamic change in the optical properties is observed for the phantom embedded with GNRs of concentrations 10, and 20 μg/ml. The discussed results are useful for the selection of GNRs dose for pre-treatment planning of plasmonic photothermal cancer therapeutics.

This paper presents an extension of the existing phase kinetics model of shape memory alloy (SMA) wire on a SMA spring actuator. The phenomenological modeling of an SMA spring under two different b...

Nanoparticles are of potential use for therapeutic applications, and nowadays a variety of modalities involving optical characteristics of nanoparticles are in the clinical translation stage. The optical properties of nanoparticles depend on their dimension and shape, wherein the larger size of the nanoparticles, as well as proximity of the nanoparticles within the near-field limit, lead to resonance peak shift in the optical spectrum. For a nanoparticle, the optical characteristics are influenced due to its aggregation and thereby critically govern the therapeutic outcome. In this article, a concise and step-by-step review of the optical properties of the nanoparticles and their aggregates is conducted. This will be useful towards the practical application for a variety of therapeutic modalities utilizing optical characteristics of nanoparticles.

Compound 1 is a potent TGF-β receptor type-1 (TGFβR1 or ALK5) inhibitor but is metabolically unstable. A solvent-exposed part of this molecule was used to analogue and modulate cell activity, liver microsome stability and mouse pharmacokinetics. The evolution of SAR that led to the selection of 2 (MDV6058 / PF-06952229) as a preclinical lead compound is described.

Nanoparticles (NPs) are miniature materials ranging from 1 to 100 nm. The NPs have unique chemical and physical properties due to their shape, size and high surface area. This research paper gives a detailed summary of the synthesis, characterization and applications of undoped and (Ag, Fe) co-doped CuO NPs with a diverse concentration of Fe (0.02, 0.04, 0.06 and 0.08 M) at a constant concentration of Ag (0.02 M). X-ray diffractometer (XRD) results revealed average crystallite size of NPs varies in the range 13.10-24.98 nm. Scanning electron microscopy (FE-SEM) showed that the morphology of pure synthesized CuO NPs and Energy dispersive x-ray spectroscopy (EDX) recognized the presence of Ag, Fe elements in the CuO lattice. The particle size obtained by transmission electron microscope (HR-TEM) images was found in the range 19.73-21.47 nm. Cu-O bond stretching of NPs was also confirmed by Fourier Transform Infrared (FTIR) techniques. The values of direct and indirect band gap for CuO were found to be 1.41-1.54 eV and 0.69-1.51 eV respectively. Antibacterial activity for synthesized NPs tested against gram-negative and gram-positive pathogenic bacteria. The photocatalytic properties of synthesized NPs were investigated by monitoring the methyl orange/methylene blue degradation in ultraviolet visible spectroscopy (UV-Vis).

Aims of the Study: The aims of the study are: (a) to compare the perceptions of dental specialists and laypeople regarding smile esthetics; (b) to compare male and female smile parameters; (c) to find influence of smile parameters on esthetics of smile. Materials and Methods: The study was conducted on 60 subjects (30 males and 30 females) of age 18 to 25 years. Frontal posed photographs of all subjects were taken using a digital camera and rated on a visual analog scale by 10 dental specialists and 10 laypersons. Measurements made on photographs were used to analyze various parameters of smile, such as buccal corridor space, smile arc, modified smile index, anterior height of smile, most posterior maxillary tooth visible, and midline relationship of central incisors to philtrum. Results: Visual analog scale values showed that 6 photographs were rated as very good (3 males, 3 females), 29 as good (11 males, 18 females), 21 as average (13 males, 8 females), and 4 photographs were rated as bad (3 males, 1 female). A high correlation was observed between ratings of dental specialists and layperson’s ratings for both male and female smiles. Most of the subjects had non-consonant smile arc, and a high correlation was found between buccal corridor space on right and left sides in both males and females. Most of the male and female smiles had an average anterior height of smile; permanent maxillary first molar was the last tooth visible during smile (73.3% females, 66.7 males); and 55% subjects had coincident midline relationship of central incisors to philtrum. Conclusion: There was no significant difference in perception of dental specialists and laypersons regarding esthetics of smile. Smile arc and anterior height of smile influenced the esthetics of smile. No significant difference was found between male and female smile parameters except modified smile index.

Plasmonic photothermal therapy (PPTT), which involves nanoparticles and near-infrared radiation (NIR) to generate confined heat, is a potential technique for selective thermal damage of cancerous tissue. Herein, tumor-selective spatial damage characteristics during polydopamine (PDA) coated gold nano blackbodies (AuNBs) mediated PPTT is investigated through a tumor-tissue mimicking phantom. The spatial temperatures during PPTT were measured within the phantom mimicking the optical scattering of superficial invasive ductal carcinoma (injected with AuNBs) surrounded by a region without AuNBs. The phantom was irradiated using broadband NIR radiation (754-816 nm), and spatial temperatures were measured using thermocouples and an infrared thermal camera. The obtained results demonstrate that the tumor region's temperature was elevated togt;50°C in about 2.5 minutes and was maintained thereafter for about 6 minutes, which is well sufficient for the thermal ablation of the tumor. While for the region surrounding the tumor, a temperature of about 40-44°C was attained, which is within safe limits for the said exposure duration. Overall, this study demonstrates that for the considered experimental parameters and tumor dimensions, heat-based thermal damage could be confined to the nanoparticle embedded tumor region while maintaining the safe temperature levels for the surrounding region, i.e., 2 mm beyond the tumor boundary.

Aggregation of the nanoparticles is a natural phenomena due to various biological and physical parameters but these aggregates are highly unstable. If aggregates would have been stable then it might be useful for some biomedical applications. To study the optical properties and photothermal heat generation of stable aggregates of the metal nanopartilces, we present a forced synthesis of aggregates of small gold nanorods in a mixture of Dulbecco's Modified Eagle's medium (DMEM) and Bovine Serum Albumin (BSA). We synthesised hexadecyltrimethylammonium bromide (CTAB) coated gold nanorods and then prepared the stable aggregates to study the optical characteristics of these aggregates. Absorption spectra of aggregates show the redshift compared to the monodispersive gold nanorods and confirm that the shape and size of aggregate depend on the amount of BSA in DMEM as well as on the concentration of CTAB in the stock solution of the gold nanorods suspension. The higher concentration of the BSA in DMEM and lower concentration of CTAB of monodispersive gold nanorod suspension causes greater redshift. We tuned the well defined plasmonic absorption resonance peaks of the aggregates of gold nanorods up to the second biological therapeutic window. We studied the stability of the synthesised aggregates of gold nanorods for up to one week and found that the aggregates were stable for atleast one week. A photothermal study of these aggregates was also carried out using high power broadband near-infrared light source. Aggregates were also photothermally stable which warrants their repeated use for such applications. The photothermal conversion efficiency of the these stable gold nanorod aggregates were higher than its monodispersive form of the nanorods., 15 pages, 6 figures

Proximity of the metal nanoparticles enhance the plasmonic coupling and shifts the resonance. This article presents a numerical study of the photothermal effect in aggregates of small gold nanorods considering the ordered as well as random aggregates. In the ordered aggregates, there is lateral coupling which causes blueshifts in the plasmonic resonance, while in the random aggregates there are redshifts in the plasmonic resonance. The plasmon response of latter could be tailored up to the second infrared biological therapeutic window. It has been observed that the aggregates show higher absorption power and therefore, higher temperature rise compared to the single gold nanorod or monodispersive nanorods. The absorption resonance peak position of the random aggregate depends on the incident and polarization angles of the incident light. The aggregation of the nanoparticles often inherently occurs in the biological medium which affects the photothermal process. This study helps to understand the photothermal heating of nanoparticle aggregates and the use of the optimal light source concerning the absorption peak of the aggregates suspension for therapeutic uses.

Aim: Blood perfusion-based requirement of nanoparticle dose-loadings is computed for plasmonic photothermal therapy of a tumor. Methods: Thermal damage is quantified through coupled multiphysics approach to specify nanoparticle loadings. Results: For low blood perfusion, the nanoparticle loading of 1 mm at 0.02 mg/ml or 3 mm at 0.2 mg/ml concentration may be chosen depending upon the desired tumor margins. For high blood perfusion, nanoparticle loading of 3 mm at 0.2 mg/ml concentration with irradiation parameters of 1 W/cm2 and 200 s seems desirable. Conclusion: Lower nanoparticle loadings within deeper periphery of tumor damage the deeper healthy tissue. If tumor margin is not to be ablated, then higher nanoparticle loadings should be opted instead of higher irradiation duration.

Photothermal therapy requires focusing of a beam on a tissue for the therapy. One such development work involves use of a halogen lamp and plano-convex lens to focus a broadband beam to achieve certain beam diameter depending on the tissue surface to be treated. For the system development, it is observed that the lens operating temperature reaches to ~130 °C in steady state condition. So, there is need to estimate the effect of variation in the wavelength of light, as well effect of thermal operating conditions for a suitable lens material. So, the variation in focal length as well spot diameter of fused silica and borosilicate crown (BK-7) plano-convex lenses is analyzed by using ZEMAX software considering the change in incident wavelength and operating temperature of the lens. It is observed that the effective focal length of the fused silica lens varies considerably as compared to that of BK-7 lens due to change in temperature and incident wavelength.

Nuclear receptors, liver X receptor-α (LXRα) and liver X receptor-β (LXRβ), are considered master regulators of lipid homeostasis and play pivotal roles in several physiological and pathological processes ranging from energy supply, cardiovascular, immunity, neurodegenerative disorders and cancer. Therapeutic agonism of the LXR/ApoE axis has proven to promote anti-tumor immunity by targeting immunosuppressive innate immune cells.1 LXR-ApoE pathway regulate the innate immune system in cancer, via modulation of the activity and abundance of myeloid derived suppressor cells (MDSC) and DCs. ApoE binds to Lipoprotein receptor-related protein (LRP) on MDSC induces apoptosis, thus resulting in immune-mediated anti-tumor activity of LXR agonists. Development of LXR agonists as therapeutics has proven quite challenging due to their precipitation of hepatic steatosis and hypertriglyceridemia. Most of the lipogenic effects of LXR agonists are mediated through LXRα.2 LXR subtype-specific agonists (LXRβ specific), may overcome hepatic triglyceride accumulation and (transient) hypertriglyceridemia. Here we report the discovery of IBS624 which is the most selective LXR agonist till date, >185X selective for LXRβ over LXRα. IBS-624 has reasonable exposure in mouse with 40% oral bioavailability. IBS-624 was well tolerated at 100mg/kg, BID for 14 days with no increase in triglycerides and neutropenia. IBS-624 has shown efficacy in MC38 colon cancer model as single agent as well as in combination with Checkpoint inhibitor. 1. Cell. 2018, 172(4): 825-840. 2. Biochemical pharmacology 2006, 71, 453-463 Citation Format: Brahmam Pujala, Balaji Dashrath Sathe, Ashu Gupta, Abhinandan Danodia, Sanjeev Soni, Vivek Kumar, Uzma Saeed, Sarvajit Chakravarty. Discovery of LXRβ selective agonists promote immune cell activation and induce tumor growth inhibition in syngeneic tumor model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5465.

Image-guided medical interventions facilitates precise visualization at treatment site. The conformal prediction for sparing healthy tissue fringes precisely in the vicinity of irregular tumour anatomy remains clinically challenging. Pre-clinical image-based computational modelling is imperative as it helps in enhancement of treatment quality, augmenting clinical-decision making, while planning, targeting, controlling, monitoring and assessing treatment response with an effective risk assessment before the onset of treatment in clinical settings. In this study, the influence of heat deposition rate (SAR), exposure duration, and variable blood perfusion metrics for a patient-specific breast tumour is quantified considering the tumour margins thereby suggesting need of geometrically accurate models.A three-dimensional realistic model mimicking dimensions of a female breast, comprising ~1.7 cm irregular tumour, was generated from patient specific two-dimensional DICOM format MRI images through image segmentation tools MIMICS 19.0® and 3-Matic 11.0® which is finally exported to COMSOL Multiphysics 5.2® as a volumetric mesh for finite element analysis. The Pennes bioheat transfer model and Arrhenius thermal damage model of cell-death are integrated to simulate a coupled biophysics problem. A comparative blood perfusion analysis is done to evaluate the response of tumour during heating considering thermal damage extent, including the tumour margins while sparing critical adjoining healthy tissues.The evaluated thermal damage zones for 1 mm, 2 mm and 3 mm fringe heating region (beyond tumour boundary) reveals 0.09%, 0.21% and 0.34% thermal damage to the healthy tissue (which is1%) and thus successful necrosis of the tumour. The iterative computational experiments suggests treatment margins5 mm are sufficient enough as heating beyond 3 mm fringe layer leads to higher damage surrounding the tumour approximately 1.5 times the tumour volume. Further, the heat-dosage requirements are 22% more for highly perfused tumour as compared to moderately perfused tumour with an approximate double time to ablate the whole tumour volume.Depending on the blood perfusion characteristics of a tumour, it is a trade-off between heat-dosage (SAR) and exposure/treatment duration to get desired thermal damage including the irregular tumour boundaries while taking into account, the margin of healthy tissue. The suggested patient-specific integrated multiphysics-model based on MRI-Images may be implemented for pre-treatment planning based on the tumour blood perfusion to evaluate the thermal ablation zone dimensions clinically and thereby avoiding the damage of off-target tissues. Thus, risks involving underestimation or overestimation of thermal coagulation zones may be minimised while preserving the surrounding normal breast parenchyma.

Over the last few decades, medical-assisted robots have been considered by many researchers, within the research domain of robotics. In this article, a 5-degrees-of-freedom spatial medical manipulator is analyzed for path planning, based on inverse kinematic solutions. Analytical methods have generally employed for finding the inverse kinematic solutions in earlier studies. However, this method is only appreciable in case of closed-form solutions. The unusual joint configurations of considered manipulator result in more complexity to attain the closed-form solutions, analytically. To overcome with shortcomings of analytical method, a non-traditional approach named adaptive neuro-fuzzy inference system is proposed under the class of artificial intelligent techniques. This article presents this neuro-fuzzy approach for desired path generation by 5-degrees-of-freedom manipulator. The estimation of percentage error between actual path and adaptive neuro-fuzzy inference system–generated path is done with respect to x, y, and z directions, respectively. Furthermore, the error between actual and predicted values regarding joint parameters is calculated for a certain arm matrix. The prototype of 5-degrees-of-freedom medical-assisted manipulator is developed at CSIR-CSIO Laboratory Chandigarh, which is also termed as patient-side manipulator to be utilized in robot-assisted surgery. Through the simulation runs, in this work, it is found that the results from adaptive neuro-fuzzy inference system approach are quite satisfactory and acceptable.

This article presents a comparative analysis of four numerical approaches—Newton Raphson method, trust region dogleg method, implicit solver (IS) based method considering a proposed simplified differential phase kinetics as well as an existing arbitrary loading based phase kinetics to solve the constitutive equation of shape memory alloy (SMA). These numerical methods can be applied to model any SMA-based actuator under thermo-mechanical loading. To demonstrate these methods, a configuration of SMA wire with a normal bias spring is considered as a case study, and its mathematical model is solved with the above-mentioned numerical approaches. Further, a comparative study is carried out that compares the solutions obtained via these methods and with the published literature. It highlights the numerical stability, computational time, and the level of complexity for the implementation of the numerical methods. The study details out both the merits and demerits of the presented numerical methods and the computational algorithms to implement these methods. Among the discussed methods, it is concluded that the IS-based numerical method with the proposed differential form of Chung’s phase kinetics model seems better for implementing the constitutive modeling for the selected case study.

The prime objective of this work is to deal with the kinematics of spatial hybrid manipulators. In this direction, in 1955, Denavit and Hartenberg proposed a consistent and concise method, known as D-H parameters method, to deal with kinematics of open serial chains. From literature review, it is found that D-H parameter method is widely used to model manipulators consisting of lower pairs. However, the method leads to ambiguities when applied to closed-loop, tree-like and hybrid manipulators. Furthermore, in the dearth of any direct method to model closed-loop, tree-like and hybrid manipulators, revisions of this method have been proposed from time-to-time by different researchers. One such kind of revision using the concept of dummy frames has successfully been proposed and implemented by the authors on spatial hybrid manipulators. In that work, authors have addressed the orientational inconsistency of the D-H parameter method, restricted to body-attached frames only. In the current work, the condition of body-attached frames is relaxed and spatial frame attachment is considered to derive the kinematic model of a 7-degree of freedom spatial hybrid robotic arm, along with the development of closed-loop constraints. The validation of the new kinematic model has been performed with the help of a prototype of this 7-degree of freedom arm, which is being developed at Council of Scientific & Industrial Research–Central Scientific Instruments Organisation Chandigarh to aid the surgeon during a medical surgical task. Furthermore, the developed kinematic model is used to develop the first column of the Jacobian matrix, which helps in providing the estimate of the tip velocity of the 7-degree of freedom manipulator when the first joint velocity is known.

Nanotechnology driven cancer theranostics hold potential as promising future clinical modalities. Currently, there is a strong emphasis on the development of combinational modalities, especially for cancer treatment. In this study, we present a topical hydrogel patch for nanomaterial-assisted photothermal therapeutics as well as for on-demand drug delivery application. The patch was derived from interpenetrating networks (IPNs) of alginate (Alg) and polyacrylamide (PAAm) in weight ratio 8:1 by free radical polymerization. The patch interiors were composed of hybrid nanostructures derived from gold nanorods (AuNRs) anchored onto polyvinylpyrrolidone (PVP) functionalized graphene oxide (PVP-nGO) to form PVP-nGO@AuNRs hybrids. Field emission scanning electron microscopy (FE-SEM) images revealed the porous nature of the hybrid hydrogel patch with an average pore size of ~28.60 ± 3.10 μm. Besides, functional characteristics of the hybrid patch, such as mechanical strength, viscoelastic and swelling behavior, were investigated. Under near-infrared (NIR) radiation exposure, the hybrid patch exhibited photothermal properties such as surface temperature rise to 75.16 ± 0.32 °C, sufficient to ablate cancer cells thermally. Besides, the heat generated in the hybrid patch could be transmitted to an underlying hydrogel (mimicking skin tissue) when stacked together without much loss. Under cyclic photothermal heating, the patch could retain its photothermal stability for four cycles. Furthermore, the hybrid patch demonstrated NIR stimulated drug release, which was evaluated using methotrexate (MTX, water-insoluble anticancer drug) and rhodamine B (RhB, water-soluble dye). Taken together, this work provides a new dimension towards the development of externally placed hydrogel patches for thermal destruction of localized solid tumors and tunable delivery of chemotherapeutic drugs at the target site.

Nowadays, foodborne disease emerging as major health concern, can add extra burden to our existing health system. Mostly, conventional method used to monitor the food bacterial contamination, but these methods are cumbersome, thus can’t fulfil the needs of modern time. Currently, nanotechnology have emerged as a wonderful tool for bacterial detection. The unique optical and plasmonic properties of metallic nanoparticles make them exceptional and novel for their integration into biosensor for bacterial detection. In this work, graphene oxide (GO) coated gold nanoparticles (AuNPs) based hybrid antibody biosensor has been developed for fast, specific and higher sensitivity foodborne bacterial detection. Polyethylene glycol (PEG) grafted GO coated AuNPs were covalently conjugated with two different types of antibodies using well known EDC-NHS chemistry. Various spectrophotometric and microscopic techniques have been used to probe the sensitivity of prepared biosensor. A colorimetric and spectrophotometric change upto 103 and 102 CFU, respectively was observed by incubating probe for 5 min. with Escherichia coli and Salmonella typhimurium. Immobilized antibodies on hybrid nanoparticle biosensor are specific for bacteria, however prepared biosensor also exhibited specific photoablation of bacteria after infra-red (NIR) exposure. Rapid optical detection and extermination of foodborne bacteria were achieved by antibody functionalized hybrid nanoparticles based biosensor.

Summary Since last three decades, research in the field of robot kinematics is boosted-up among different researchers worldwide. This is mainly due to their increased use in various challenging fields of engineering and science. One such challenging application is the use of master–slave concept in a robot-assisted surgery. The authors have already performed the kinematic study and gravity balancing of seven degrees-of-freedom (DOFs) surgeon-side manipulator ( Singh et al., 2015a , Singh et al., 2015b ). To meet these challenging demands, the most important aspect of a robotic manipulator is to develop an accurate kinematic model. In this direction, different researchers in the literature have made significant contributions. Out of these, the most prominent one is D–H parameters method, which was proposed by Denavit and Hartenberg in 1955. In the present work, this method is applied to a five-DOFs spatial manipulator, named as patient-side manipulator, which tracks the motion of surgeon-side manipulator during a robot-assisted surgery. The prototype considered in this work is a spatial serial manipulator, being developed at CSIR-CSIO Chandigarh. Experimental validations are performed and results are found to be in close agreement.

This paper investigates the controllable therapeutic parameters for plasmonic photothermal ablation of a tumor with an objective to specify the parameters (irradiation intensity, irradiation duration, nanoparticle concentration) based on spatial distribution and accumulation of nanoparticles within a tumor. In this study, a melanoma surrounded by healthy tissue is analyzed. Monte Carlo method, Beer's law, and Pennes’ bioheat equation are used to compute spatiotemporal thermal ablation zones. Results show that depending on spatial extent of nanoparticle loaded region of a tumor as well as nanoparticle concentration, different ablation zones are attained within tumor. It is shown that a nanoparticle concentration of 0.0001% embedded within 2–3-mm thick tumor periphery, along with irradiation intensity of 1 W/cm2 for duration of 110 s, is required to attain thermal ablation for the considered tumor sizes of 20–40 mm diameter. For lesser extent of nanoparticle loaded region, it is not possible to attain thermal ablation even with higher nanoparticle concentrations. Further it is shown that, for future clinical application of such therapy, through intravenous delivery of nanoparticles, a tumor must possess a certain spatial extent of vascularized region to facilitate the accumulation of nanoparticles in desired concentration for thermal ablation.

Nanoparticle-assisted thermal ablation therapy has recently evolved as a promising future therapy for cancer treatment. This therapy is advantageous because it is potentially much more selective than traditional methods (surgery or chemotherapy) in terms of destroying cancerous cells while leaving healthy tissue intact. In this study, heat confinement and thus the healthy tissue sparing characteristics, were experimentally investigated. Two Agarose gel samples of cylindrical shape were synthesized for evaluating the heat confinement in the axial and radial directions. A specified region of the gel was embedded with gold nanoparticles which were synthesized in this study (mimicking an injection of nanoparticles to the tumor region), while the rest of the plain gel mimics the surrounding healthy tissue. These Agarose gel samples were irradiated through fiber optic and the spatiotemporal temperature response was measured. A numerical model was also developed and validated against these experiments. The measurements were then extended to real tumor-tissue by taking into account blood perfusion and metabolic heat generation. It is observed that with the proposed approach, heat can be well confined to the nanoparticle embedded region. This study shows that with a well-designed system it is possible to obtain thermal ablation of the tumor region while sparing healthy tissue 3 mm beyond the tumor boundary.

The main focus of this work is to extend the applicability of D-H parameter method to develop a kinematic model of a hybrid manipulator. A hybrid manipulator is a combination of open- and closed-loop chains and contains planar and spatial links. It has been found in the literature that D-H parameter method leads to ambiguities, when dealing with closed-loop chains. In this work, it has been observed that the D-H parameter method, when applied to a hybrid manipulator, results in an orientational inconsistency, because of which the method cannot be used to develop the kinematic model. In this article, the concept of dummy frames is proposed to resolve the orientational inconsistency and to develop the kinematic model of a hybrid manipulator. Moreover, the prototype of 7-degree-of-freedom hybrid manipulator, known as a surgeon-side manipulator to assist the surgeon during a medical surgery, is also developed to validate the kinematic model derived in this work.

Objectives: To compare the shear bond strength of recycled orthodontic metal brackets using an adhesion booster and conventional primer and using the Adhesive Remnant Index (ARI) score to assess the site of debonding. Materials and Methods: Eighty premolar teeth were randomly divided into 3 groups of 20 teeth each: Group A-New brackets and Transbond XT, Group B-Recycled brackets and Transbond XT, Group C-Recycled brackets and Transbond XT + Enhance LC. Brackets were recycled using sandblaster. Bond strength was tested on a universal testing machine and remnant adhesive on the tooth surface was determined. Kruskal Wallis test and Mann Whitney test were carried out to know the significant difference between the groups. Chi – square test was used to determine significant differences in the ARI (Adhesive Remnant Index) scores. Results: Highest mean load was recorded in Group A (9.58±1.72 MPa), followed by Group C (8.60±2.05 MPa) and Group B (6.39±1.64 MPa). Chi- square test indicated significant differences (P=.002) in ARI scores. Group A and Group C were associated significantly for score 2 of ARI; Group B for Score 0 of ARI. Conclusion: The bond strength of recycled orthodontic brackets with Transbond XT was significantly lower when compared to bond strength of recycled brackets with an adhesion booster. After recycling the brackets with sandblaster and using an adhesion booster, the previously debonded brackets gave the bond strength comparable to new brackets with Transbond XT. The ARI data showed statistically significant association between the ARI scores and the groups.