20 results on '"Shaikh JS"'
Search Results
2. A Successful Pregnancy Outcome Using Laser-Assisted Hatching and Platelet-Rich Plasma Perfusion in Advanced Maternal and Paternal Age: A Case Report.
- Author
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Shaikh JS, More A, Nair N, Shrivastava J, and Pareek C
- Abstract
Infertility affects millions globally, with advanced parental age posing a significant risk. This case report details a couple who experienced secondary infertility for 12 years. Following multiple unsuccessful attempts at assisted reproductive technology (ART), a personalized treatment regimen involving platelet-rich plasma (PRP) perfusion and laser-assisted hatching (LAH) resulted in a successful pregnancy. Diagnostic evaluations identified specific reproductive challenges, leading to tailored interventions. A positive pregnancy outcome was achieved after PRP treatment enhanced endometrial thickness and LAH facilitated embryo implantation. This case highlights the importance of individualized treatment strategies in infertility management and proves the potential efficacy of PRP and LAH in overcoming recurrent implantation failure. Further research is needed to explain the roles of PRP and LAH in improving pregnancy outcomes, especially in older parents and couples with a history of failed in vitro fertilization (IVF) treatments., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Shaikh et al.)
- Published
- 2024
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3. Investigations on a solar humidification dehumidification desalination system equipped with various packing materials and multi-stage bubble column dehumidifier.
- Author
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Shaikh JS and Ismail S
- Subjects
- Temperature, Bandages, Fresh Water, Sunlight, Water
- Abstract
This work presents the theoretical and experimental investigation of a solar-powered humidification dehumidification desalination (HDD) system with different humidifier packing materials and a two-stage bubble column dehumidifier (BCD). Naturally available coconut shells (CS) and coconut shells with drilled holes (CSH) on the surface to improve water permeability were used as packing materials in the humidifier, and their performance was compared with that of commercial-type pall ring (PR) and raschig ring (RR) packings. An in-house developed numerical model of the HDD system in conjunction with a flat plate solar water collector was used in this study. Steady-state experimental results showed that CSH packing exhibited the highest volumetric mass transfer coefficient (0.00852 kg/s), resulting in maximum humidifier efficiency (96%) and freshwater yield (2.16 kg/hr), followed by PR (0.00841 kg/s, 94%, and 2.137 kg/hr), CS (0.00831 kg/s, 90%, and 2.127 kg/hr), and RR (0.0081 kg/s, 81%, and 2.087 kg/hr) at feedwater mass flow rate of 1.5 kg/min and humidifier inlet temperature of 75 [Formula: see text]. Furthermore, transient outdoor test results showed that using a two-stage configuration in a BCD increased the daily average effectiveness to 0.93, as against 0.79 for a single-stage BCD. Employing CSH instead of PR and RR packings in the humidifier reduced freshwater costs by 6.2% and 7.6%, respectively., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2023
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4. Emotion Recognition from Spatio-Temporal Representation of EEG Signals via 3D-CNN with Ensemble Learning Techniques.
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Yuvaraj R, Baranwal A, Prince AA, Murugappan M, and Mohammed JS
- Abstract
The recognition of emotions is one of the most challenging issues in human-computer interaction (HCI). EEG signals are widely adopted as a method for recognizing emotions because of their ease of acquisition, mobility, and convenience. Deep neural networks (DNN) have provided excellent results in emotion recognition studies. Most studies, however, use other methods to extract handcrafted features, such as Pearson correlation coefficient (PCC), Principal Component Analysis, Higuchi Fractal Dimension (HFD), etc., even though DNN is capable of generating meaningful features. Furthermore, most earlier studies largely ignored spatial information between the different channels, focusing mainly on time domain and frequency domain representations. This study utilizes a pre-trained 3D-CNN MobileNet model with transfer learning on the spatio-temporal representation of EEG signals to extract features for emotion recognition. In addition to fully connected layers, hybrid models were explored using other decision layers such as multilayer perceptron (MLP), k-nearest neighbor (KNN), extreme learning machine (ELM), XGBoost (XGB), random forest (RF), and support vector machine (SVM). Additionally, this study investigates the effects of post-processing or filtering output labels. Extensive experiments were conducted on the SJTU Emotion EEG Dataset (SEED) (three classes) and SEED-IV (four classes) datasets, and the results obtained were comparable to the state-of-the-art. Based on the conventional 3D-CNN with ELM classifier, SEED and SEED-IV datasets showed a maximum accuracy of 89.18% and 81.60%, respectively. Post-filtering improved the emotional classification performance in the hybrid 3D-CNN with ELM model for SEED and SEED-IV datasets to 90.85% and 83.71%, respectively. Accordingly, spatial-temporal features extracted from the EEG, along with ensemble classifiers, were found to be the most effective in recognizing emotions compared to state-of-the-art methods.
- Published
- 2023
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5. Rational La-doped hematite as an anode and hydrous cobalt phosphate as a battery-type electrode for a hybrid supercapacitor.
- Author
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Shaikh NS, Lokhande VC, Ji T, Ubale S, Mane VJ, Lokhande CD, Shaikh HM, Shaikh JS, Praserthdam S, Sabale S, and Kanjanaboos P
- Abstract
In recent years, modern appliances require high energy density with a burst power supply. Hybrid supercapacitors show high performance based on high energy density without compromising power density and stability over thousands of charge-discharge cycles. In this work, the optimized hybrid electrodes using lanthanum-doped hematite (lanthanum-doped iron oxide) noted as 7.5%La-HMT as a negative electrode and hydrous cobalt phosphate (CoPO) as a battery-type positive electrode have been successfully fabricated via a simple hydrothermal method and a facile co-precipitation method, respectively. The 7.5%La-HMT showed excellent electrochemical performance due to doping of rare-earth La
3+ metal ions, resulting in improvised active sites and reduction in the equivalent resistance. The 7.5%La-HMT operated at a high potential window (0 to -1.2 V) with an ultra-high specific capacitance ( Sp ) of 1226.7 F g-1 at 1 A g-1 with capacitance retention of 89.3% over 1000 cycles. CoPO could be operated at a high working window (0 to 0.45 V) with a specific capacity of 121.7 mA h g-1 at a current density of 2 A g-1 with capacitance retention of 85.4% over 1000 cycles. The configured CoPO//KOH//10%La-HMT aqueous hybrid capacitor device (Aq-HSC) could be operated at a potential window of 1.6 V and delivered a maximum energy density (E.D) of 83.6 W h kg-1 at a power density (P.D) of 3.2 kW kg-1 with Sp of 235.0 F g-1 at 2 A g-1 and 89.0% Sp retention over 5000 cycles. The simplicity of the synthesis methods for CoPO and 7.5%La-HMT along with their superior super-capacitive properties make them suitable for advanced electrical devices and hybrid vehicles.- Published
- 2022
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6. A self-aligning end-effector robot for individual joint training of the human arm.
- Author
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Balasubramanian S, Guguloth S, Mohammed JS, and Sujatha S
- Abstract
Aim: Intense training of arm movements using robotic devices can help reduce impairments in stroke. Recent evidence indicates that independent training of individual joints of the arm with robots can be as effective as coordinated multi-joint arm training. This makes a case for designing and developing robots made for training individual joints, which can be simpler and more compact than the ones for coordinate multi-joint arm training. The design of such a robot is the aim of the work presented in this paper., Methods: An end-effector robot kinematic design was developed and the optimal robot link lengths were estimated using an optimization procedure. A simple algorithm for automatically detecting human limb parameters is proposed and its performance was evaluated through a simulation study., Results: A six-degrees-of-freedom end-effector robot with three actuated degrees-of-freedom and three non-actuated self-aligning degrees-of-freedom for safe assisted training of the individual joints (shoulder or elbow) of the human arm was conceived. The proposed robot has relaxed constraints on the relative positioning of the human limb with respect to the robot. The optimized link lengths chosen for the robot allow it to cover about 80% of the human limb's workspace, and possess good overall manipulability. The simple estimation procedure was demonstrated to estimate human limb parameters with low bias and variance., Discussion: The proposed robot with three actuated and three non-actuated degrees-of-freedom has a compact structure suitable for both the left and right arms without any change to its structure. The proposed automatic estimation procedure allows the robot to safely apply forces and impose movements to the human limb, without the need for any manual measurements. Such compact robots have the highest potential for clinical translation., Competing Interests: Declaration of conflicting interests: The author(s) declare no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2021.)
- Published
- 2021
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7. The implementation of graphene-based aerogel in the field of supercapacitor.
- Author
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Shaikh JS, Shaikh NS, Mishra YK, Pawar SS, Parveen N, Shewale PM, Sabale S, Kanjanaboos P, Praserthdam S, and Lokhande CD
- Abstract
Graphene and graphene-based hybrid materials have emerged as an outstanding supercapacitor electrode material primarily because of their excellent surface area, high electrical conductivity, and improved thermal, mechanical, electrochemical cycling stabilities. Graphene alone exhibits electric double layer capacitance (EDLC) with low energy density and high power density. The use of aerogels in a supercapacitor is a pragmatic approach due to its extraordinary properties like ultra-lightweight, high porosity and specific surface area. The aerogels encompass a high volume of pores which leads to easy soak by the electrolyte and fast charge-discharge process. Graphene aerogels assembled into three-dimensional (3D) architecture prevent there stacking of graphene sheets and maintain the high surface area and hence excellent cycling stability and rate capacitance. However, the energy density of graphene aerogels is limited due to EDLC type of charge storage mechanism. Consequently, 3D graphene aerogel coupled with pseudocapacitive materials such as transition metal oxides, metal hydroxides, conducting polymers, nitrides, chalcogenides show an efficient energy density and power density performance due to the presence of both types of charge storage mechanisms. This laconic review focuses on the design and development of graphene-based aerogel in the field of the supercapacitor. This review is an erudite article about methods, technology and electrochemical properties of graphene aerogel., (© 2021 IOP Publishing Ltd.)
- Published
- 2021
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8. Discovery of isoquinolinone and naphthyridinone-based inhibitors of poly(ADP-ribose) polymerase-1 (PARP1) as anticancer agents: Structure activity relationship and preclinical characterization.
- Author
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Karche NP, Bhonde M, Sinha N, Jana G, Kukreja G, Kurhade SP, Jagdale AR, Tilekar AR, Hajare AK, Jadhav GR, Gupta NR, Limaye R, Khedkar N, Thube BR, Shaikh JS, Rao Irlapati N, Phukan S, Gole G, Bommakanti A, Khanwalkar H, Pawar Y, Kale R, Kumar R, Gupta R, Praveen Kumar VR, Wahid S, Francis A, Bhat T, Kamble N, Patil V, Nigade PB, Modi D, Pawar S, Naidu S, Volam H, Pagdala V, Mallurwar S, Goyal H, Bora P, Ahirrao P, Singh M, Kamalakannan P, Naik KR, Kumar P, Powar RG, Shankar RB, Bernstein PR, Gundu J, Nemmani K, Narasimham L, George KS, Sharma S, Bakhle D, Kamboj RK, and Palle VP
- Subjects
- Animals, Antineoplastic Agents metabolism, Antineoplastic Agents pharmacology, Antineoplastic Agents therapeutic use, Binding Sites, Cell Line, Tumor, Cell Survival drug effects, Half-Life, Humans, Mice, Mice, Inbred BALB C, Molecular Docking Simulation, Naphthyridines metabolism, Neoplasms drug therapy, Neoplasms pathology, Poly (ADP-Ribose) Polymerase-1 metabolism, Poly(ADP-ribose) Polymerase Inhibitors metabolism, Poly(ADP-ribose) Polymerase Inhibitors pharmacology, Poly(ADP-ribose) Polymerase Inhibitors therapeutic use, Quinolones metabolism, Structure-Activity Relationship, Transplantation, Heterologous, Antineoplastic Agents chemistry, Naphthyridines chemistry, Poly (ADP-Ribose) Polymerase-1 antagonists & inhibitors, Poly(ADP-ribose) Polymerase Inhibitors chemistry, Quinolones chemistry
- Abstract
The exploitation of GLU988 and LYS903 residues in PARP1 as targets to design isoquinolinone (I & II) and naphthyridinone (III) analogues is described. Compounds of structure I have good biochemical and cellular potency but suffered from inferior PK. Constraining the linear propylene linker of structure I into a cyclopentene ring (II) offered improved PK parameters, while maintaining potency for PARP1. Finally, to avoid potential issues that may arise from the presence of an anilinic moiety, the nitrogen substituent on the isoquinolinone ring was incorporated as part of the bicyclic ring. This afforded a naphthyridinone scaffold, as shown in structure III. Further optimization of naphthyridinone series led to identification of a novel and highly potent PARP1 inhibitor 34, which was further characterized as preclinical candidate molecule. Compound 34 is orally bioavailable and displayed favorable pharmacokinetic (PK) properties. Compound 34 demonstrated remarkable antitumor efficacy both as a single-agent as well as in combination with chemotherapeutic agents in the BRCA1 mutant MDA-MB-436 breast cancer xenograft model. Additionally, compound 34 also potentiated the effect of agents such as temozolomide in breast cancer, pancreatic cancer and Ewing's sarcoma models., (Copyright © 2020 Elsevier Ltd. All rights reserved.)
- Published
- 2020
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9. Discovery of Novel, Potent, Brain-Permeable, and Orally Efficacious Positive Allosteric Modulator of α7 Nicotinic Acetylcholine Receptor [4-(5-(4-Chlorophenyl)-4-methyl-2-propionylthiophen-3-yl)benzenesulfonamide]: Structure-Activity Relationship and Preclinical Characterization.
- Author
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Sinha N, Karche NP, Verma MK, Walunj SS, Nigade PB, Jana G, Kurhade SP, Hajare AK, Tilekar AR, Jadhav GR, Thube BR, Shaikh JS, Balgude S, Singh LB, Mahimane V, Adurkar SK, Hatnapure G, Raje F, Bhosale Y, Bhanage D, Sachchidanand S, Dixit R, Gupta R, Bokare AM, Dandekar M, Bharne A, Chatterjee M, Desai S, Koul S, Modi D, Mehta M, Patil V, Singh M, Gundu J, Goel RN, Shah C, Sharma S, Bakhle D, Kamboj RK, and Palle VP
- Subjects
- Alzheimer Disease drug therapy, Animals, Brain metabolism, Clinical Trials as Topic, Drug Stability, Humans, Male, Molecular Structure, Nicotinic Agonists chemical synthesis, Nicotinic Agonists pharmacokinetics, Nootropic Agents chemical synthesis, Nootropic Agents pharmacokinetics, Rats, Sprague-Dawley, Rats, Wistar, Structure-Activity Relationship, Sulfonamides chemical synthesis, Sulfonamides pharmacokinetics, Thiophenes chemical synthesis, Thiophenes pharmacokinetics, Drug Discovery, Nicotinic Agonists pharmacology, Nootropic Agents pharmacology, Sulfonamides pharmacology, Thiophenes pharmacology, alpha7 Nicotinic Acetylcholine Receptor agonists
- Abstract
The discovery of a series of thiophenephenylsulfonamides as positive allosteric modulators (PAM) of α7 nicotinic acetylcholine receptor (α7 nAChR) is described. Optimization of this series led to identification of compound 28, a novel PAM of α7 nicotinic acetylcholine receptor (α7 nAChR). Compound 28 showed good in vitro potency, with pharmacokinetic profile across species with excellent brain penetration and residence time. Compound 28 robustly reversed the cognitive deficits in episodic/working memory in both time-delay and scopolamine-induced amnesia paradigms in the novel object and social recognition tasks, at very low dose levels. Additionally, compound 28 has shown excellent safety profile in phase 1 clinical trials and is being evaluated for efficacy and safety as monotherapy in patients with mild to moderate Alzheimer's disease.
- Published
- 2020
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10. Quantum Dot Based Solar Cells: Role of Nanoarchitectures, Perovskite Quantum Dots, and Charge-Transporting Layers.
- Author
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Shaikh JS, Shaikh NS, Mali SS, Patil JV, Beknalkar SA, Patil AP, Tarwal NL, Kanjanaboos P, Hong CK, and Patil PS
- Abstract
Quantum dot solar cells (QDSCs) are attractive technology for commercialization, owing to various advantages, such as cost effectiveness, and require relatively simple device fabrication processes. The properties of semiconductor quantum dots (QDs), such as band gap energy, optical absorption, and carrier transport, can be effectively tuned by modulating their size and shape. Two types of architectures of QDSCs have been developed: 1) photoelectric cells (PECs) fabricated from QDs sensitized on nanostructured TiO
2 , and 2) photovoltaic cells fabricated from a Schottky junction and heterojunction. Different types of semiconductor QDs, such as a secondary, ternary, quaternary, and perovskite semiconductors, are used for the advancement of QDSCs. The major challenge in QDSCs is the presence of defects in QDs, which lead to recombination reactions and thereby limit the overall performance of the device. To tackle this problem, several strategies, such as the implementation of a passivation layer over the QD layer and the preparation of core-shell structures, have been developed. This review covers aspects of QDSCs that are essential to understand for further improvement in this field and their commercialization., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)- Published
- 2019
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11. Symmetric supercapacitor: Sulphurized graphene and ionic liquid.
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Shaikh JS, Shaikh NS, Kharade R, Beknalkar SA, Patil JV, Suryawanshi MP, Kanjanaboos P, Hong CK, Kim JH, and Patil PS
- Abstract
Symmetric supercapacitor is advanced over simple supercapacitor device due to their stability over a large potential window and high energy density. Graphene is a desired candidate for supercapacitor application since it has a high surface area, good electronic conductivity and high electro chemical stability. There is a pragmatic use of ionic liquid electrolyte for supercapacitor due to its stability over a large potential window, good ionic conductivity and eco-friendly nature. For high performance supercapacitor, the interaction between ionic liquid electrolyte and graphene are crucial for better charge transportation. In respect of this, a three-dimensional (3D) nanoporous honeycomb shaped sulfur embedded graphene (S-graphene) has been synthesized by simple chemical method. Here, the fabrication of high performance symmetric supercapacitor is done by using S-graphene as an electrode and [BMIM-PF
6 ] as an electrolyte. The particular architecture of S-graphene benefited to reduce the ion diffusion resistance, providing the large surface area for charge transportation and efficient charge storage. The S-graphene and ionic liquid-based symmetric supercapacitor device showed the large potential window of 3.2 V with high energy density 124 Wh kg-1 at 0.2 A g-1 constant applied current density. Furthermore, this device shows good cycling performance (stability) with a capacitive retention of 95% over 20,000 cycles at a higher current density of 2 A g-1 ., (Copyright © 2018 Elsevier Inc. All rights reserved.)- Published
- 2018
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12. Nanoarchitectures in dye-sensitized solar cells: metal oxides, oxide perovskites and carbon-based materials.
- Author
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Shaikh JS, Shaikh NS, Mali SS, Patil JV, Pawar KK, Kanjanaboos P, Hong CK, Kim JH, and Patil PS
- Abstract
Dye-sensitized solar cells (DSSCs) have aroused great interest and been regarded as a potential renewable energy resource among the third-generation solar cell technologies to fulfill the 21
st century global energy demand. DSSCs have notable advantages such as low cost, easy fabrication process and being eco-friendly in nature. The progress of DSSCs over the last 20 years has been nearly constant due to some limitations, like poor long-term stability, narrow absorption spectrum, charge carrier transportation and collection losses and poor charge transfer mechanism for regeneration of dye molecules. The main challenge for the scientific community is to improve the performance of DSSCs by using different approaches, like finding new electrode materials with suitable nanoarchitectures, dyes in composition with promising semiconductors and metal quantum dot fluorescent dyes, and cost-effective hole transporting materials (HTMs). This review focuses on DSSC photo-physics, which includes charge separation, effective transportation, collection and recombination processes. Different nanostructured materials, including metal oxides, oxide perovskites and carbon-based composites, have been studied for photoanodes, and counter electrodes, which are crucial to achieve DSSC devices with higher efficiency and better stability.- Published
- 2018
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13. Statin Use And Risk Of Developing Diabetes In Cardiovascular Disease: Systematic Literature Review And Meta-Analysis.
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Thakker D, Nair SR, Shukla H, and Shaikh JS
- Published
- 2014
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14. Investigations on silver/polyaniline electrodes for electrochemical supercapacitors.
- Author
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Patil DS, Shaikh JS, Pawar SA, Devan RS, Ma YR, Moholkar AV, Kim JH, Kalubarme RS, Park CJ, and Patil PS
- Abstract
Polyaniline (PANI) and silver doped polyaniline (Ag/PANI) thin films were deposited on stainless steel substrates by a dip coating technique. To study the effect of doping concentration of Ag on the specific capacitance of PANI the concentration of Ag was varied from 0.3 to 1.2 weight percent. Fourier transform-infrared and Fourier transform-Raman spectroscopy, and energy dispersion X-ray techniques were used for the phase identification and determination of the doping content in the PANI films, respectively. The surface morphology of the films was examined by Field Emission Scanning Electron Microscopy, which revealed a nanofiber like structure for PANI and nanofibers with bright spots of Ag particles for the Ag/PANI films. There was decrease in the room temperature electrical resistivity of the Ag/PANI films of the order of 10(2) with increasing Ag concentration. The supercapacitive behavior of the electrodes was tested in a three electrode system using 1.0 M H(2)SO(4) electrolyte. The specific capacitance increased from 285 F g(-1) (for PANI) to 512 F g(-1) for Ag/PANI at 0.9 weight percent doping of Ag, owing to the synergic effect of PANI and silver nanoparticles. This work demonstrates a simple strategy of improving the specific capacitance of polymer electrodes and may also be easily adopted for other dopants.
- Published
- 2012
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15. Supported nanocomposite membranes: bridging microtechnology with nanotechnology.
- Author
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Mohammed JS and McShane MJ
- Abstract
Bridging top-down and bottom-up manufacturing approaches is desirable to exploit the advantages of both approaches. A simple method that combines microfabrication technique with layer-by-layer self-assembly for in situ fabrication of supported nanocomposite membrane structures is presented. To our knowledge, our approach has yielded the largest nanocomposite membrane size. The micro/nanostructures presented in this work can find broad applicability for sensors, MEMS/bioMEMS, cell biology, microfluidics, and lab-on-chip devices.
- Published
- 2009
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16. Microfluidic device for multimodal characterization of pancreatic islets.
- Author
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Mohammed JS, Wang Y, Harvat TA, Oberholzer J, and Eddington DT
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- Animals, Enzyme-Linked Immunosorbent Assay, Mice, Mice, Inbred BALB C, Mice, Inbred C57BL, Islets of Langerhans cytology, Microfluidics instrumentation
- Abstract
A microfluidic device to perfuse pancreatic islets while simultaneously characterizing their functionality through fluorescence imaging of the mitochondrial membrane potential and intracellular calcium ([Ca(2+)](i)) in addition to enzyme linked immunosorbent assay (ELISA) quantification of secreted insulin was developed and characterized. This multimodal characterization of islet function will facilitate rapid assessment of tissue quality immediately following isolation from donor pancreas and allow more informed transplantation decisions to be made which may improve transplantation outcomes. The microfluidic perfusion chamber allows flow rates of up to 1 mL min(-1), without any noticeable perturbation or shear of islets. This multimodal quantification was done on both mouse and human islets. The ability of this simple microfluidic device to detect subtle variations in islet responses in different functional assays performed in short time-periods demonstrates that the microfluidic perfusion chamber device can be used as a new gold standard to perform comprehensive islet analysis and obtain a more meaningful predictive value for islet functionality prior to transplantation into recipients, which is currently difficult to predict using a single functional assay.
- Published
- 2009
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17. Polymer/colloid surface micromachining: micropatterning of hybrid multilayers.
- Author
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Mohammed JS and McShane M
- Subjects
- Nanoparticles chemistry, Nanotechnology methods, Particle Size, Surface Properties, Colloids chemistry, Membranes, Artificial, Polymers chemistry
- Abstract
Fabrication of multicomponent patterned films comprising polymer/nanoparticle multilayers using conventional lithography and bottom-up layer-by-layer nanofabrication techniques is described. The work is motivated by the potential to extend polymer surface micromachining capabilities toward construction of integrated systems by connecting discrete domains of active materials containing functional nanoparticles. Modified surfaces illustrate tunability of the physical (thickness, roughness, 3D structures) and chemical (inorganic/organic material combinations) properties of the nanocomposite micropatterns. Intriguing nanoscale phenomena were observed for the structures when the order of material deposition was changed; the final multilayer thickness and surface roughness and mechanical integrity of the patterns were found to be interdependent and related to the roughness of layers deposited earlier in the process.
- Published
- 2008
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18. Rapid prototyping for neuroscience and neural engineering.
- Author
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Tek P, Chiganos TC, Mohammed JS, Eddington DT, Fall CP, Ifft P, and Rousche PJ
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- Animals, Biocompatible Materials, Biomedical Engineering methods, Brain Ischemia physiopathology, Cerebral Cortex physiology, Craniotomy methods, Diffusion Chambers, Culture instrumentation, Diffusion Chambers, Culture methods, Electrodes, Implanted trends, Electronics, Medical methods, Electrophysiology methods, Equipment Design methods, Image Processing, Computer-Assisted instrumentation, Image Processing, Computer-Assisted methods, Male, Neurophysiology instrumentation, Neurophysiology methods, Neurosciences methods, Organ Culture Techniques instrumentation, Organ Culture Techniques methods, Polymers, Rats, Rats, Sprague-Dawley, Time Factors, Biomedical Engineering instrumentation, Computer-Aided Design instrumentation, Electronics, Medical instrumentation, Electrophysiology instrumentation, Equipment Design instrumentation, Neurosciences instrumentation
- Abstract
Rapid prototyping (RP) is a useful method for designing and fabricating a wide variety of devices used for neuroscience research. The present study confirms the utility of using fused deposition modeling, a specific form of RP, to produce three devices commonly used for basic science experimentation. The accuracy and precision of the RP method varies according to the type and quality of the printer as well as the thermoplastic substrate. The printer was capable of creating device channels with a minimum diameter of 0.4 or 0.6mm depending on the orientation of fabrication. RP enabled the computer-aided design and fabrication of three custom devices including a cortical recording/stroke induction platform capable of monitoring electrophysiological function during ischemic challenge. In addition to the recording platform, two perfusion chambers and a cranial window device were replicated with sub-millimeter precision. The ability to repeatedly modify the design of each device with minimal effort and low turn-around time is helpful for oft-unpredictable experimental conditions. Results obtained from validation studies using both the cortical recording platform and perfusion chamber did not vary from previous results using traditional hand-fabricated or commercially available devices. Combined with computer-aided design, rapid prototyping is an excellent alternative for developing and fabricating custom devices for neuroscience research.
- Published
- 2008
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19. Microfluidic add-on for standard electrophysiology chambers.
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Mohammed JS, Caicedo HH, Fall CP, and Eddington DT
- Subjects
- Brain metabolism, Dopamine metabolism, Microscopy, Fluorescence, Sensitivity and Specificity, Brain pathology, Electrophysiology instrumentation, Microfluidic Analytical Techniques instrumentation
- Abstract
We have developed a microfluidic brain slice device (microBSD) that marries an off-the shelf brain slice perfusion chamber with an array of microfluidic channels set into the bottom surface of the chamber substrate. As this device is created through rapid prototyping, once optimized, it is trivial to replicate and share the devices with other investigators. The device integrates seamlessly into standard physiology and imaging chambers and it is immediately available to the whole slice physiology community. With this technology we can address the flow of neurochemicals and any other soluble factors to precise locations in the brain slice with the temporal profile we choose. Dopamine (DA) was chosen as a model neurotransmitter and we have quantified delivery in brain tissue using cyclic voltammetry (CV) and fluorescence imaging.
- Published
- 2008
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20. Micropatterning of nanoengineered surfaces to study neuronal cell attachment in vitro.
- Author
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Mohammed JS, DeCoster MA, and McShane MJ
- Subjects
- Animals, Cells, Cultured, Rats, Biomedical Engineering methods, Nanotechnology methods, Neurons chemistry, Neurons cytology
- Abstract
Methods for producing protein patterns with defined spatial arrangement and micro- and nanoscale features are important for studying cellular-level interactions, including basic cell-cell communications, cell signaling, and mechanisms of drug action. Toward this end, a straightforward, versatile procedure for fabricating micropatterns of bioactive nanofilm coatings as multifunctional biological testbeds is demonstrated. The method, based on a combination of photolithography and layer-by-layer self-assembly (LbL), allows for precise construction of nanocomposite films of potentially complex architecture, and patterning of these films on substrates using a modified lift-off (LO) procedure. As a first step in evaluating nanostructures made with this process, "comparison chips," comprising two coexisting regions of square patterns with relevant proteins/polypeptides on a single substrate, were fabricated with poly(diallyldimethylammonium chloride) (PDDA) as a cell-repellent background. Using neuronal cells as a model biological system, comparison chips were produced with secreted phospholipase A2 (sPLA2), a known membrane-active enzyme for neurons, for direct comparison with gelatin, poly-l-lysine (PLL), or bovine serum albumin (BSA). Fluorescence microscopy, surface profilometry, and atomic force microscopy techniques were used to evaluate the structural properties of the patterns on these chips and show that the patterning technique was successful. Preliminary cell culture studies show that neurons respond and bind specifically to the sPLA2 enzyme embedded in the polyelectrolyte thin films and present as the outermost layer. These findings point to the potential for this method to be applied in developing test substrates for a broad array of studies aimed at identifying important biological structure-function relationships.
- Published
- 2004
- Full Text
- View/download PDF
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