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M V, Joshi H, A S A, Dey R. Supported Nickel Nanoparticles as Catalyst in Direct sp 3 C-H Alkylation of 9H-Fluorene Using Alcohols as Alkylating Agent. Chem Asian J 2025; 20:e202400989. [PMID: 39400506 DOI: 10.1002/asia.202400989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2024] [Revised: 09/29/2024] [Accepted: 10/12/2024] [Indexed: 10/15/2024]
Abstract
Herein, we report an inexpensive first-row transition metal Ni heterogeneous catalytic system for the Csp 3-mono alkylation of fluorene using alcohols as alkylating agents via borrowing hydrogen strategy. The catalytic protocol displayed versatility with high yields of the desired products using various types of primary alcohols, including aryl/hetero aryl methanols, and aliphatic alcohols as alkylating agents. The catalyst Ni NPs@N-C was synthesized via high-temperature pyrolysis strategy, using ZIF-8 as the sacrificial template. The Ni NPs@N-C catalyst was characterized by XPS, HR-TEM, HAADF-STEM, XRD and ICP-MS. The catalyst is stable even in the air at room temperature, displayed excellent activity and could be recycled 5 times without appreciable loss of its activity.
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Dey R, Saha S, Molla SH, Nandi S, Samadder A. Structure-based drug design of pre-clinical candidate nanopiperine: a direct target for CYP1A1 protein to mitigate hyperglycaemia and associated microbes. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2024; 35:1071-1093. [PMID: 39629730 DOI: 10.1080/1062936x.2024.2434934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2024] [Accepted: 11/21/2024] [Indexed: 01/04/2025]
Abstract
Diabetes is attributed to an increased vulnerability to bacterial infection linked to unregulated hyperglycaemia. The present study highlights the formulation of nanoparticles with phyto-compound piperine (PIP) encapsulated within non-toxic biodegradable polymer poly-lactide co-glycolide (PLGA) which showed a variety in surface functionality, biocompatibility, and the ability to tailor an optimized release rate from its polymeric enclosure. The observations revealed that nanopiperine (NPIP) pre-treatment in mice inhibited alteration in hepatic tissue architecture and hepato-biochemical parameters in diabetes and its associated bacterial infections. NPIP also decreased the propensity of lipids to undergo an oxidation process and stabilized the membrane lipids in vivo, thereby lowering oxidative stress and preventing enzymatic activation of CYP1A1. This result is corroborated with the in silico molecular docking study where PIP binding with CYP1A1 gave -11.32 Kcal/mol dock score value. The antibacterial activity of PIP was further demonstrated by the in silico PIP and Ef-Tu protein-binding efficacy revealing -6.48 Kcal/mol score value which was coupled with the results of in vitro studies where the zone of inhibition assay with NPIP against Staphylococcus aureus and Escherichia coli. Thus, NPIP could serve as a potential drug candidate in modulating targeted proteins to inhibit the progression of hyperglycaemia and its associated microbes.
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Dey R, Schaubel DE, Hanley JA, Saha-Chaudhuri P. Time-dependent prognostic accuracy measures for recurrent event data. Biometrics 2024; 80:ujae150. [PMID: 39723565 DOI: 10.1093/biomtc/ujae150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 09/16/2024] [Accepted: 11/20/2024] [Indexed: 12/28/2024]
Abstract
In many clinical contexts, the event of interest could occur multiple times for the same patient. Considerable advancement has been made on developing recurrent event models based on or that use biomarker information. However, less attention has been given to evaluating the prognostic accuracy of a biomarker or a composite score obtained from a fitted recurrent event-rate model. In this manuscript, we propose novel measures to characterize the prognostic accuracy of a marker measured at baseline in the presence of recurrent events. The proposed estimators are based on a semiparametric frailty model that accounts for the informativeness of a marker and unobserved heterogeneity among patients with respect to the rate of event occurrence. We investigate the asymptotic properties of the proposed accuracy estimators and demonstrate these estimators' finite sample performance through simulation studies. The proposed estimators have minimal bias and appropriate coverage. The estimators are applied to evaluate the performance of a baseline forced expiratory volume, a measure of lung capacity, for repeated episodes of pulmonary exacerbations in patients with cystic fibrosis.
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Maqungo S, Nicol A, Yimam H, Dey R, Exadaktylos A, Laubscher M. CT scan-based 3D fracture mapping in civilian gunshot intracapsular fractures of the femur neck. Injury 2024; 55:111723. [PMID: 39018833 DOI: 10.1016/j.injury.2024.111723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 06/20/2024] [Accepted: 07/07/2024] [Indexed: 07/19/2024]
Abstract
INTRODUCTION Displaced intracapsular neck of femur (NOF) fractures secondary to civilian gunshots are rare injuries with universally poor outcomes following surgical fixation. No studies have been published on fracture mapping in NOF fractures secondary to civilian gunshots. OBJECTIVES We performed CT scan-based fracture mapping to identify the most common fracture patterns in these injuries. METHODS Design: Retrospective search of prospectively collected data. SETTING Single Level 1 Trauma hospital. Patient selection criteria: All patients presenting with gunshot fractures to the femur neck between 01 January 2009 and 31 December 2022 were identified. Once identified from Picture Archiving and Communication System (PACS), computed tomography (CT) scans in Digital Imaging and Communication in Medicine (DICOM) format were imported into Mimics 16 software and fracture fragments were segmented and three-dimensional (3D) reconstruction was generated. The reduced fractures were exported to 3-Matic software to merge the fragments and adjust the orientation in three planes. An uninjured femur model was used as a template for reduction. Fracture lines and heat maps were then generated. Our outcome measures were successful mapping of the identified fracture lines. RESULTS A total of 25 intracapsular femur neck fractures were identified and suitable for CT scan mapping. All patients were male with an average age of 22 (range 18-32). Once generated, fracture maps were used to show the location, distribution and frequency of the fracture lines. In all but two cases the fracture line propagation remained within the confines of the hip joint capsule. In three cases there was fracture extension into the superior aspect of the femur head, and in one case extension into the inferior aspect. CONCLUSION This is the first study to perform 3D fracture mapping for intracapsular femur neck fractures secondary to civilian gunshot injuries. The exercise has helped us better understand the commonest fracture patterns and assisted us with surgical planning and execution.
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Dey R, Mondal A, Kumar S. Bootstrap tests for simultaneous monotone ordering of effects in a two-way ANOVA. Biom J 2024; 66:e2300238. [PMID: 38581103 DOI: 10.1002/bimj.202300238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 01/05/2024] [Accepted: 02/09/2024] [Indexed: 04/08/2024]
Abstract
In a two-way additive analysis of variance (ANOVA) model, we consider the problem of testing for homogeneity of both row and column effects against their simultaneous ordering. The error variances are assumed to be heterogeneous with unbalanced samples in each cell. Two simultaneous test procedures are developed-the first one using the likelihood ratio test (LRT) statistics of two independent hypotheses and another based on the consecutive pairwise differences of estimators of effects. The parametric bootstrap (PB) approach is used to find critical points of both the tests and the asymptotic accuracy of the bootstrap is established. An extensive simulation study shows that the proposed tests achieve the nominal size and have very good power performance. The robustness of the tests is also analyzed under deviation from normality. An "R" package is developed and shared on "GitHub" for ease of implementation of users. The proposed tests are illustrated using a real data set on the mortality due to alcoholic liver disease and it is shown that age and gender have a significant impact on the increasing incidence of mortality.
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P H, M V, Dey R. Multicomponent synthesis via acceptorless alcohol dehydrogenation: an easy access to tri-substituted pyridines. RSC Adv 2024; 14:10761-10767. [PMID: 38572342 PMCID: PMC10988360 DOI: 10.1039/d4ra00439f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 03/06/2024] [Indexed: 04/05/2024] Open
Abstract
Herein, we report palladium supported on a hydroxyapatite catalyst for synthesizing tri-substituted pyridines using ammonium acetate as the nitrogen source via acceptorless alcohol dehydrogenation strategy. The strategy offers a broad substrate scope using inexpensive and readily available alcohols as the starting material. The catalyst was prepared using a simple method and analyzed by several techniques, including FE-SEM, EDS, HR-TEM, BET, XRD, FT-IR, UV-visible spectroscopy, and XPS, demonstrating the anchoring of Pd nanoparticles on hydroxyapatite in the zero oxidation state. Moreover, several controlled experiments were carried out to understand the reaction pathway and a suitable mechanism has been proposed.
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Shah K, Ghosh J, Patel S, Chowdhuri MB, Jadeja KA, Shukla G, Macwan T, Kumar A, Dolui S, Singh K, Tanna RL, Patel KM, Dey R, Manchanda R, Ramaiya N, Kumar R, Aich S, Yadava N, Purohit S, Gupta MK, Nagora UC, Pathak SK, Atrey PK, Mayya KBK. Author Correction: Role of pinch in Argon impurity transport in ohmic discharges of Aditya-U Tokamak. Sci Rep 2023; 13:19969. [PMID: 37968383 PMCID: PMC10651834 DOI: 10.1038/s41598-023-47362-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2023] Open
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Shah K, Ghosh J, Patel S, Chowdhuri MB, Jadeja KA, Shukla G, Macwan T, Kumar A, Dolui S, Singh K, Tanna RL, Patel KM, Dey R, Manchanda R, Ramaiya N, Kumar R, Aich S, Yadava N, Purohit S, Gupta MK, Nagora UC, Pathak SK, Atrey PK, Mayya KBK. Role of pinch in Argon impurity transport in ohmic discharges of Aditya-U Tokamak. Sci Rep 2023; 13:16087. [PMID: 37752170 PMCID: PMC10522584 DOI: 10.1038/s41598-023-42746-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Accepted: 09/14/2023] [Indexed: 09/28/2023] Open
Abstract
We present experimental results of the trace argon impurity puffing in the ohmic plasmas of Aditya-U tokamak performed to study the argon transport behaviour. Argon line emissions in visible and Vacuum Ultra Violet (VUV) spectral ranges arising from the plasma edge and core respectively are measured simultaneously. During the experiments, space resolved brightness profile of Ar1+ line emissions at 472.69 nm (3p44s 2P3/2-3p44p 2D3/2), 473.59 nm (3p44s 4P5/2-3p44p 4P3/2), 476.49 nm (3p44s 2P1/2-3p44p 2P3/2), 480.60 nm (3p44s 4P5/2-3p44p 4P5/2) are recorded using a high resolution visible spectrometer. Also, a VUV spectrometer has been used to simultaneously observe Ar13+ line emission at 18.79 nm (2s22p 2P3/2-2s2p2 2P3/2) and Ar14+ line emission at 22.11 nm (2s2 1S0-2s2p 1P1). The diffusivity and convective velocity of Ar are obtained by comparing the measured radial emissivity profile of Ar1+ emission and the line intensity ratio of Ar13+ and Ar14+ ions, with those simulated using the impurity transport code, STRAHL. Argon diffusivities ~ 12 m2/s and ~ 0.3 m2/s have been observed in the edge (ρ > 0.85) and core region of the Aditya-U, respectively. The diffusivity values both in the edge and core region are found to be higher than the neo-classical values suggesting that the argon impurity transport is mainly anomalous in the Aditya-U tokamak. Also, an inward pinch of ~ 10 m/s mainly driven by Ware pinch is required to match the measured and simulated data. The measured peaked profile of Ar density suggests impurity accumulation in these discharges.
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P H, Hati S, Dey R. S-Alkylation of dithiocarbamates via a hydrogen borrowing reaction strategy using alcohols as alkylating agents. Org Biomol Chem 2023; 21:6360-6367. [PMID: 37489908 DOI: 10.1039/d3ob00958k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/26/2023]
Abstract
Herein, we report an operationally simple, environmentally benign and scalable approach towards the synthesis of S-benzyl/alkyl dithiocarbamates via a hydrogen borrowing reaction between alcohols and dithiocarbamate anions catalyzed using a hydroxyapatite-supported copper nano-catalyst. This strategy has a broad substrate scope and offers high yields of products using inexpensive and readily available alcohols as starting materials. The catalyst was prepared by easy and straightforward methods and analyzed by several analytical techniques, e.g., FESEM, HR-TEM, BET, XRD, EDS, and XPS, demonstrating the anchoring of Cu nanoparticles on hydroxyapatite in the zero oxidation state.
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P H, M V, Tomasini M, Poater A, Dey R. Transition metal-free synthesis of 2-aryl quinazolines via alcohol dehydrogenation. MOLECULAR CATALYSIS 2023. [DOI: 10.1016/j.mcat.2023.113110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
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Prasad JK, Dey R, Raghuwanshi R. Exopolysaccharide-Producing Rhizospheric Bacteria Enhance Yield via Promoting Wheat (Triticum aestivum L.) Growth at Early Stages. Microbiology (Reading) 2022. [DOI: 10.1134/s0026261721102622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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Ramaiya N, Manchanda R, Chowdhuri MB, Yadava N, Dey R, Kumar A, Shah K, Patel S, Jadeja KA, Patel KM, Kumar R, Aich S, Pathak SK, Tanna RL, Ghosh J. Initial results from near-infrared spectroscopy on ADITYA-U tokamak. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:113552. [PMID: 36461425 DOI: 10.1063/5.0101850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 09/12/2022] [Indexed: 06/17/2023]
Abstract
Spectroscopy in vacuum ultraviolet (VUV) and visible ranges plays an important role in the investigation and diagnosis of tokamak plasmas. However, under harsh environmental conditions of fusion grade devices, such as ITER, VUV-visible systems encounter many issues due to the degradation of optical components used in such systems. Here, near-infrared (NIR) spectroscopy has become an effective tool in understanding the edge plasma dynamics. Considering its importance, a NIR spectroscopic diagnostic has been developed and installed on the ADITYA-U tokamak. The system consists of a 0.5 m spectrometer having three gratings with different groove densities, and it is coupled with a linear InGaAs photodiode array. Radiation from the ADITYA-U edge plasma has been collected using a collimating lens and optical fiber combination and transported to the spectrometer. The spectrum in the NIR range from the ADITYA-U plasma has been recorded using this system, in which Paβ and Paγ along with many spectral lines from neutral and singly ionized impurities have been observed. The influxes of H and C have been estimated from measurements. The H influx value is found to be 2.8 × 1016 and 1.9 × 1016 particles cm-2 s-1 from neutral hydrogen lines Hα and Paβ, respectively, and the C influx value is found to be 3.5 × 1015 and 2.9 × 1015 particles cm-2 s-1 from the neutral carbon and singly ionized carbon, respectively. A good agreement is seen between these results and the results obtained by using a routine photomultiplier tube based diagnostic.
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Mapondela KB, Dey R, Levin M. Usability study of a sleeve attachment device for enhancing ease of use of metered dose inhalers in children. S Afr Med J 2022; 112:842-849. [PMID: 36420730 DOI: 10.7196/samj.2022.v112i11.16671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Indexed: 06/16/2023] Open
Abstract
BACKGROUND Children with asthma often lack the strength to activate their pressurised metered dose inhaler (pMDI). A recently developed sleeve device that attaches to a pMDI reduces the activation force of pMDIs from 36 - 39 Newtons (N) to 12.6 N and monitors the remaining doses with a built-in counter. OBJECTIVES To examine the usability and patient experience of the Easy Squeezy (ES) sleeve attachment device in the paediatric patient population. METHODS This cross-over study included 40 participants aged 5 - 10 years, half of whom had previous experience in using a pMDI. The experienced participants had used a pMDI for at least 1 year, and the inexperienced participants had no experience of using a pMDI. Participants and their parents recorded their responses on the ease of use, perceptions and satisfaction with using the pMDI alone and the pMDI with the ES. RESULTS The participants felt that it was easier for them to activate the pMDI using the ES. They liked the ES device more than the pMDI and felt happier using the ES device. The parents reported that their children would be happier using the ES and would find it easier to activate the pMDI using the ES, that the built-in counter in the ES would make it easier to keep track of the doses, and that their children would be more likely to take the ES to school and use it there compared with the pMDI. They would recommend the ES to other parents and were willing to buy the device with their own money. CONCLUSION The paediatric participants and their parents reported that the ES made it easier for children to activate the pMDI, that the counter made it easier to keep count of the doses, and that the aesthetics of the ES could potentially remove the stigma attached to use of a pMDI.
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Madassery GP, M V, Panja S, P H, Dey R. Metal‐Free Synthesis of S‐Aryldithiocarbamates: Aryl C−S Bond Formation at Room Temperature†. ChemistrySelect 2022. [DOI: 10.1002/slct.202202136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Rachuene A, Dey R, de Villiers S, Berry K, Mulder M, du Plessis J, Roche S. Retrospective audit of serum vitamin D levels in patients who underwent Latarjet procedure for anterior shoulder instability. SA ORTHOPAEDIC JOURNAL 2022. [DOI: 10.17159/2309-8309/2022/v21n4a4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND: The aim of this study was to review vitamin D levels in patients who underwent Latarjet procedures at a tertiary teaching hospital and a private clinic. METHODS: A retrospective review of clinical and radiological records was performed for 22 patients who underwent Latarjet procedure between November 2017 and June 2019. Postoperative vitamin D levels were retrieved and classified into sufficient (> 75 nmol/L), insufficient (25-75 nmol/L), and deficient (< 25 nmol/L) groups. Two observers assessed radiographic images of the patients at six weeks and three months after surgery. Any bone resorption, fracture and nonunion were reported, and interobserver reliability was analysed using the intraclass correlation coefficient (ICC). RESULTS: The median age was 20.5 years and was predominantly male. A little more than two-thirds (68.1%) of the patients were found to have insufficient or deficient levels of vitamin D. One patient from the insufficient group had postoperative bone resorption. Good interobserver reliability was observed with the ICC value being 0.86. CONCLUSION: This study found a prevalence of insufficient/deficient vitamin D levels in young patients undergoing a Latarjet procedure. This study serves as a reminder to orthopaedic surgeons that vitamin D deficiency is prevalent among patients undergoing Latarjet Level of evidence: Level 4.
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Mukherjee C, Kundu A, Dey R, Banerjee A, Sengupta K. Active microrheology using pulsed optical tweezers to probe viscoelasticity of lamin A. SOFT MATTER 2021; 17:6787-6796. [PMID: 34219136 DOI: 10.1039/d1sm00293g] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Lamins are nucleoskeletal proteins of mammalian cells that stabilize the structure and maintain the rigidity of the nucleus. These type V intermediate filament proteins which are predominantly of A and B types provide necessary tensile strength to the nucleus. Single amino acid missense mutations occurring all over the lamin A protein form a cluster of human diseases termed as laminopathies, most of which principally affect the muscle and cardiac tissues responsible for load bearing functionalities of the body. One such mutation is A350P which causes dilated cardiomyopathy in patients. It is postulated that a change from alanine to proline in the α-helical coiled-coil forming 2B rod domain of the protein might severely disrupt the propensity of the filaments to polymerise into functional higher order structures required to form a fully functional lamina with its characteristic elasticity. In this study, we have elucidated for the very first time, the application of active microrheology employing oscillating optical tweezers to investigate any alterations in the viscoelastic parameters of the mutant protein meshwork in vitro, which might translate into possible changes in nuclear plasticity. We confirmed our findings from this robust yet fast method by imaging both the wild type and mutant lamin A networks using a super resolution microscope, and observed changes in the mesh size which corroborate our measured changes in the viscoelastic parameters of the lamins. This method could thus be extended to conduct microrheological measurements on any intermediate filament protein thus bearing significant implications in laminopathies and other diseases associated with intermediate filaments.
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Moonda Z, Nortje MB, Dey R. Does the intra-operatively measured leg length correction compare to the post-operative radiograph in total hip replacement surgery? SA ORTHOPAEDIC JOURNAL 2020. [DOI: 10.17159/2309-8309/2020/v19n4a2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
ABSTRACT BACKGROUND: This study aims to analyse the accuracy of the Vertical Measurement System™ (VMS) in assessing the leg length correction (LLC) during total hip arthroplasty (THA) by comparing the intra-operative measurements to the radiographic measurements obtained six weeks post-operatively Patients and methods: A prospective cohort study was conducted in which patients undergoing primary THA were enrolled at two centres in Cape Town, over a period of 19 weeks. THAs were performed by four surgeons. Pre-operative leg length discrepancy (LLD) measurements were obtained in 92 patients. The VMS was used to predict intra-operative LLC, and this measurement was compared to the post-operative LLC measured on the six-week follow-up X-ray. These measurements were statistically compared using the Mann-Whitney U test. RESULTS: The difference between the intra-operative VMS calculation and the six-week radiological measurement was not significant (p>0.05), with the difference in their mean values being 0.1±3.3 mm. In the cohort, 82% of the patients (n=75) were within 5 mm of the target LLC, and 96% of patients (n=88) were within 10 mm of the target LLC. The mean absolute residual LLD at six weeks was 3.2±3.1 mm. CONCLUSION: The intra-operative LLC measurement obtained using the VMS accurately predicts the six-week post-operative radiographic LLC measurement Level of evidence: Level 4 Keywords: total hip replacement, leg length discrepancy, leg length correction, vertical measurement system, comparative study, longitudinal study
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Panchoo P, Wiegerinck J, Boskovic V, Laubscher M, Maqungo S, McCollum G, Dey R. Outcomes of primary fusion in high-energy Lisfranc injuries at a tertiary state hospital. SA ORTHOPAEDIC JOURNAL 2020. [DOI: 10.17159/2309-8309/2020/v19n3a4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
ABSTRACT BACKGROUND: High-energy Lisfranc injuries are relatively uncommon but can lead to severe disability and morbidity. Primary fusion is a treatment option that can improve outcomes and reduce the reoperation rate. The aim of this study was to evaluate our series of primary fusions for high-energy Lisfranc injuries, looking specifically at type of fusion, time to union, non-union rates, reoperation rates and quality of reduction METHODS: Patients who underwent surgery for Lisfranc injuries were identified from the REDCap surgical database and then retrieved from records. Only cases of primary fusion in adults were included. We excluded low-energy sprains and athletic injuries, ipsilateral lower limb injuries and cases where reduction and fixation were done. Radiographs were analysed from the iSite Enterprise PACS system (Philips® RESULTS: Between 2013 and 2018, 12 cases of high-energy Lisfranc injuries were identified where primary fusion was done. Seven patients (58%) underwent fusion of the first, second and third tarsometatarsal (TMT) joints. The first and second TMT joints were fused in only one case (8%), and the second and third TMT joints were fused in four cases (33%). Only one patient (8%) had removal of implants. Compression plating was the technique of choice used for fusion. There was l0o% union rate and average time to union was 84 days. Acceptable reduction was observed in nine cases (75%). Three cases (25%) of malreduction were found, among which one patient had pre-existing hallux valgus CONCLUSION: The majority of patients who underwent primary fusion of at least one TMT joint had good radiological outcome. Further studies with better clinical follow-up are needed Level of evidence: Level 4 Keywords: Lisfranc, tarsometatarsal, outcome, fusion
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Dey R, Patnaik S, Nair G, Steiner S, Sivarasu S. An intra-operative device for parallel drilling and femoral landmark estimation during medial patellofemoral ligament reconstructive surgery. SA ORTHOPAEDIC JOURNAL 2020. [DOI: 10.17159/2309-8309/2020/v19n4a3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
ABSTRACT BACKGROUND: The aim of this study was to design and test a device to guide medial patellofemoral reconstruction surgeries. Materials and methods: A three-dimensional (3D) printed, modular and cost-effective medial patellofemoral ligament (MPFL) reconstruction guide, Pat-Rig, was designed with parallel holes running in the medio-lateral direction. This device was manufactured using a commercial additive manufacturing facility, and bench tested using a custom-built test rig. CT scans of patella bones were reconstructed, and the device was tested on four 3D-printed patellas of various sizes. RESULTS: The device was successful in guiding the surgical drill into the patella to drill parallel holes adhering to the current surgical requirements and specifications. The device was augmented with an innovative radiopaque scale which can allow the surgeon to accurately predict the landmarks to drill and measure the drill depth of the tunnels. CONCLUSION: There are no devices on the market that accurately predict the drill locations on the patella during MPFL reconstruction surgeries. The device, Pat-Rig, was found to overcome the current limitations of the MPFL surgeries and was able to provide satisfactory surgical guidance during the reconstruction. Level of evidence: Level 5 Keywords: knee surgery, patella, orthopaedic, MPFL reconstruction, 3D-printed, novel surgical device.
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Dey R, Samantaray MK, Poater A, Hamieh A, Kavitake S, Abou-Hamad E, Callens E, Emwas AH, Cavallo L, Basset JM. Synthesis and characterization of a homogeneous and silica supported homoleptic cationic tungsten(vi) methyl complex: application in olefin metathesis. Chem Commun (Camb) 2018; 52:11270-11273. [PMID: 27709169 DOI: 10.1039/c6cc05352a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A method for the synthesis of a homogeneous cationic tungsten(vi)pentamethyl complex [(WMe5)+(C6F5)3BMe-] from neutral tungstenhexamethyl (WMe6) and a silica supported cationic tungstentetramethyl complex [([triple bond, length as m-dash]Si-O-)WMe4+ (C6F5)3BMe-] from a neutral silica supported tungstenpentamethyl complex [([triple bond, length as m-dash]Si-O-)WMe5] is described. In both cases a direct demethylation using the B(C6F5)3 reagent was used. The aforesaid complexes were characterized by liquid or solid state NMR spectroscopy. Interestingly, the homogeneous cationic complex [(WMe5)+(C6F5)3BMe-] shows moderate activity whereas the supported cationic complex [([triple bond, length as m-dash]Si-O-)WMe4+(C6F5)3BMe-] exhibits good activity in olefin metathesis reactions.
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Chaudhuri A, Dey R. Chimney Endovascular Reconstruction of the Aortic Bifurcation (Ch-ERAB) for Aorto-iliac Occlusive Disease Allows Inferior Mesenteric Arterial Preservation. Eur J Vasc Endovasc Surg 2017; 54:404. [PMID: 28602579 DOI: 10.1016/j.ejvs.2017.05.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Accepted: 05/09/2017] [Indexed: 10/19/2022]
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Samantaray MK, Kavitake S, Morlanés N, Abou-Hamad E, Hamieh A, Dey R, Basset JM. Unearthing a Well-Defined Highly Active Bimetallic W/Ti Precatalyst Anchored on a Single Silica Surface for Metathesis of Propane. J Am Chem Soc 2017; 139:3522-3527. [DOI: 10.1021/jacs.6b12970] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Hamieh A, Dey R, Nekoueishahraki B, Samantaray MK, Chen Y, Abou-Hamad E, Basset JM. Single site silica supported tetramethyl niobium by the SOMC strategy: synthesis, characterization and structure–activity relationship in the ethylene oligomerization reaction. Chem Commun (Camb) 2017. [DOI: 10.1039/c7cc02585h] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Facile synthesis of two SOMC-based niobium methyl complexes which showed different selectivity in ethylene oligomerization.
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Mehta T, Dey R, Chaudhuri A. Ilioprofunda Endobypass Can Successfully Treat a Post-Operative Femoral Pseudo-Aneurysm. EJVES Short Rep 2016; 34:9-12. [PMID: 28856325 PMCID: PMC5576153 DOI: 10.1016/j.ejvssr.2016.11.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 11/02/2016] [Accepted: 11/07/2016] [Indexed: 12/17/2022] Open
Abstract
INTRODUCTION A 75-year-old male patient with significant cardiopulmonary comorbidity presented with a 70-mm left femoral pseudoaneurysm 6 years after aortobifemoral bypass (and prior femoral endarterectomy). REPORT As the left superficial femoral artery was occluded, an ilioprofunda endobypass was undertaken following extraperitoneal exposure of the left limb of the bypass graft with subsequent deployment of four Viabahn endoprostheses via the left limb into the proximal left deep femoral artery with successful exclusion of the pseudoaneurysm. The endografts remain patent at 6 months with regression noted in the pseudoaneurysm itself. DISCUSSION Post-operative femoral pseudoaneurysm following anastomotic dehiscence has traditionally been treated by open surgical repair. Re-re-do open femoral vascular surgery has a high complication rate. Scarring and potential graft infection may necessitate ligation of involved arteries and extra-anatomic bypasses with an attendant risk of limb loss. Although the common femoral artery is conventionally contraindicated for endograft deployment because of the perceived high risk of stent fracture in a highly mobile zone, an endobypass can avoid the potential complications of open revision groin surgery in an unfit, high-risk patient.
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Bootharaju MS, Dey R, Gevers LE, Hedhili MN, Basset JM, Bakr OM. A New Class of Atomically Precise, Hydride-Rich Silver Nanoclusters Co-Protected by Phosphines. J Am Chem Soc 2016; 138:13770-13773. [DOI: 10.1021/jacs.6b05482] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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