Inner structure- and surface-controlled hollow MnO nanocubes for high sensitive MR imaging contrast effect

Kukreja Aastha,Kang Byunghoon,Han Seungmin,Shin Moo-Kwang,손혜영,Choi Yuna,Lim Eun-Kyung,Huh Yong-Min,Haam Seungjoo 나노기술연구협의회 2020 Nano Convergence Vol.7 No.16

Manganese oxide (MnO) nanocubes were fabricated and their surface were modified by ligand encapsulation or ligand exchange, to render them water-soluble. And then, MnO formed the hollow structure by etching using acidic solution (phthalate buffer, pH 4.0). Depending on the ligand of the MnO surface, it increases the interaction between MnO and water molecules. Also, the hollow structure of MnO, as well as the ligand, can greatly enhance the acces‑ sibility of water molecules to metal ions by surface area-to-volume ratio. These factors provide high R1 relaxation, leading to strong T1 MRI signal. We have confirmed T1-weighted MR contrast effect using 4-kinds of MnO nanocubes (MnOEn, MnOEnHo, MnOEx and MnOExHo). They showed enough a MR contrast effect and biocompatibility. Espe‑ cially, among them, MnOExHo exhibited high T1 relaxivity (r1) (6.02 mM −1 s −1 ), even about 1.5 times higher sensitivity than commercial T1 MR contrast agents. In vitro/in vivo studies have shown that MnOExHo provides highly sensitive T1-weighted MR imaging, thereby improving diagnostic visibility at the disease site.

Preparation of gold core-mesoporous iron-oxide shell nanoparticles and their application as dual MR/CT contrast agent in human gastric cancer cells

Kukreja, Aastha,Kang, Byunghoon,Kim, Hyun-Ouk,Jang, Eunji,Son, Hye Young,Huh, Yong-Min,Haam, Seungjoo Elsevier 2017 Journal of industrial and engineering chemistry Vol.48 No.-

<P><B>Abstract</B></P> <P>Multifunctional nano-systems are an enticing approach toward the design of nanoparticles with desired characteristics because of interactions between various components of the system. The combination of various imaging modalities often augments the advantages and simultaneously overcomes restrictions encountered by the individual techniques. This report describes the development of multifunctional gold core/iron oxide porous-shell nanoparticles (AuFe NPs) functionalized with matrix metalloproteinase peptide for targeted multi-mode magnetic resonance and computed tomography imaging. This study demonstrates that AuFe NPs simultaneously possess both T2-based contrast effect and X-ray attenuation properties <I>in vitro</I>. The drug loading capacity of porous iron oxide shell is also proposed.</P> <P><B>Graphical abstract</B></P> <P>Schematic representation of MT1-MMP modified, doxorubicin loaded AuFe porous core/shell nanoparticles (dAuFe/Pep). The particles simultaneously possess magnetic resonance (MR) and computed tomography (CT) contrast enhancement, along with drug loading capacity.</P> <P>[DISPLAY OMISSION]</P>

One-pot synthesis of magnetic nanoclusters enabling atherosclerosis-targeted magnetic resonance imaging

Kukreja, Aastha,Lim, Eun-Kyung,Kang, Byunghoon,Choi, Yuna,Lee, Taeksu,Suh, Jin-Suck,Huh, Yong-Min,Haam, Seungjoo Dove Medical Press 2014 INTERNATIONAL JOURNAL OF NANOMEDICINE Vol.9 No.-

<P>In this study, dextran-encrusted magnetic nanoclusters (DMNCs) were synthesized using a one-pot solution phase method for detection of atherosclerosis by magnetic resonance imaging. Pyrenyl dextran was used as a surfactant because of its electron-stabilizing effect and its amphiphilic nature, rendering the DMNCs stable and water-dispersible. The DMNCs were 65.6±4.3 nm, had a narrow size distribution, and were superparamagnetic with a high magnetization value of 60.1 emu/g. Further, they showed biocompatibility and high cellular uptake efficiency, as indicated by a strong interaction between dextran and macrophages. In vivo magnetic resonance imaging demonstrated the ability of DMNCs to act as an efficient magnetic resonance imaging contrast agent capable of targeted detection of atherosclerosis. In view of these findings, it is concluded that DMNCs can be used as magnetic resonance imaging contrast agents to detect inflammatory disease.</P>

Functional rehabilitation of children with post surgical oro nasal fistula using obturators: Case reports with ten year follow up

Pratibha Kukreja,Amy Yi-Ling Chen Asia Association for Disability and Oral Health 2020 대한장애인치과학회지 Vol.16 No.1

Oronasal fistulas (ONF) present as the most common complication after cleft palate surgery. Various methods of closure have been described, depending upon site, size and tissue available. However, in certain situations, nonsurgical management is required to correct the functional deficits due to ONF.The clinical reports presented here describe the management of ONF in two paediatric patients due to flap necrosis. A fixed type of obturator with bands on upper primary second molar teeth has been described. A ten year long follow up has been presented. This paper highlights the importance of multidisciplinary approach and long term follow up for non-surgical management of ONF.

Preparation of gold core-mesoporous iron-oxide shell nanoparticles and their application as dual MR/CT contrast agent in human gastric cancer cells

Aastha Kukreja,강병훈,김현욱,장은지,손혜영,허용민,함승주 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.48 No.-

Multifunctional nano-systems are an enticing approach toward the design of nanoparticles with desiredcharacteristics because of interactions between various components of the system. The combination ofvarious imaging modalities often augments the advantages and simultaneously overcomes restrictionsencountered by the individual techniques. This report describes the development of multifunctional goldcore/iron oxide porous-shell nanoparticles (AuFe NPs) functionalized with matrix metalloproteinasepeptide for targeted multi-mode magnetic resonance and computed tomography imaging. This studydemonstrates that AuFe NPs simultaneously possess both T2-based contrast effect and X-ray attenuationproperties in vitro. The drug loading capacity of porous iron oxide shell is also proposed.

Complications of Anterior Cervical Fusion using a Low-dose Recombinant Human Bone Morphogenetic Protein-2

Sunil Kukreja,Osama I Ahmed,Justin Haydel,Anil Nanda,Anthony H Sin 대한척추신경외과학회 2015 Neurospine Vol.12 No.2

Objective: There are several reports, which documented a high incidence of complications following the use of recombinant human bone morphogenetic protein-2 (rhBMP-2) in anterior cervical fusions (ACFs). The objective of this study is to share our experience with low-dose rhBMP-2 in anterior cervical spine. Methods: We performed a retrospective analysis of 197 patients who underwent anterior cervical fusion (ACF) with the use of recombinant human bone morphogenetic protein-2 (rhBMP-2) during 2007-2012. A low-dose rhBMP-2 (0.7mg/level) sponge was placed exclusively within the cage. In 102 patients demineralized bone matrix (DBM) was filled around the BMP sponge. Incidence and severity of dysphagia was determined by 5 points SWAL-QOL scale. Results: Two patients had prolonged hospitalization due to BMP unrelated causes. Following the discharge, 13.2%(n=26) patients developed dysphagia and 8.6%(n=17) patients complained of neck swelling. More than half of the patients (52.9%, n=9) with neck swelling also had associated dysphagia; however, only 2 of these patients necessitated readmission. Both of these patients responded well to the intravenous dexamethasone. The use of DBM did not affect the incidence and severity of complications (p>0.05). Clinico-radiological evidence of fusion was not observed in 2 patients. Conclusion: A low-dose rhBMP-2 in ACFs is not without risk. However, the incidence and severity of complications seem to be lower with low-dose BMP placed exclusively inside the cage. Packing DBM putty around the BMP sponge does not affect the safety profile of rhBMP-2 in ACFs.

Enhancement of Spectrum Efficacy using Cognitive Radio Networks

Vivek Kukreja,Shailender Gupta,Bharat Bhushan,Poonam Mittal,C. K. Nagpal 보안공학연구지원센터 2015 International Journal of Future Generation Communi Vol.8 No.2

Spectrum is the most valuable and scarce resource for every wireless application. Due to the scarcity of the spectrum other alternatives are also being searched. Cognitive Radio (CR) technology is one such alternative which has gained popularity in the recent times. It has been established from various researches that the allocated band is not in use for all the time by the licensed user or as Primary Users (PUs). The Cognitive Radio users also called as Secondary Users (SUs) communicate using unlicensed band or by using the idle licensed band of primary users opportunistically. This paper evaluates the performance of routing protocols by varying concentration level of PU and SU. We have also investigated the impact of time given by PU’s to SU’s for data transfer. For performing the above task, a simulator is designed in MATLAB-7.01. The results show that the performance of routing protocols improves significantly as the number of PUs and allowable time given by PU’s to SU’s increases.

Closing the Gaps: Endoscopic Suturing for Large Submucosal and Full-Thickness Defects

Keshav Kukreja,Suma Chennubhotla,Bharat Bhandari,Ankit Arora,Shashideep Singhal 대한소화기내시경학회 2018 Clinical Endoscopy Vol.51 No.4

This article is a systematic review of relevant literature on endoscopic suturing as a primary closure technique for large submucosaland full-thickness defects after endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), and endoscopic fullthicknessresection (EFTR). A comprehensive literature search was conducted through 2016 by using PubMed, to find peer-reviewedoriginal articles. The specific factors considered were the procedural indications and details, success rates, clinical outcomes includingcomplications, and study limitations. Six original articles were included in the final review: two with non-human subjects and fourwith human subjects. The mean success rate of endoscopic suturing was 97.4% (100% for human subjects and 95.4% for non-humansubjects). The procedural time ranged from 7 to 89 min. The average size and depth of lesions were 2.71 cm (3.74 cm [human] and1.96 cm [non-human]) and 1.52 cm, respectively. The technique itself had no reported impact on mortality. In conclusion, endoscopicsuturing is a minimally invasive technique for the primary closure of defects caused by EMR, ESD, and EFTR, with a high success andlow complication rate.

A Proposed Approach for Biomedical Image Denoising Using PCA_NLM

Mohit Bansal,Munesh Devi,Neha Jain,Chinu Kukreja 보안공학연구지원센터 2014 International Journal of Bio-Science and Bio-Techn Vol.6 No.6

The main problem faced during biomedical image diagnosis is the noise introduced due to the consequence of the coherent nature of the image. The noise interfered may be Gaussian noise, speckle noise or Poisson noise, during transmission. The capturing devices itself has a salt & pepper noise. These noises corrupt the image and often lead to incorrect diagnosis. These noises make it more difficult for the observer to discriminate fine detail of the images in diagnostic examinations. Thus, denoising these noises from a noisy image has become the most important step in medical image processing. In spite of the sophistication of the recently proposed methods, most algorithms have not yet attained a desirable level of applicability. Denoising techniques are aimed at removing noise or distortion from images while retaining the original quality of the image. In this work, we propose PCA_NLM approach which computes neighborhood similarities after PCA projection. Our algorithm is based on the assumption that image contains an extensive amount of self-similarity. The accuracy and computational cost of the PCA algorithm is improved by computing neighborhood similarities, i.e., averaging weights, after a PCA projection to a lower dimensional subspace. We evaluate and compare the performance of proposed technique with different existing methods by using six quality measures PSNR, SNR, MSE, NAE, Correlation Coefficient and SSIM. Comparative analysis shows our approach give the best performance results in terms of improved quality measures as well as visual interpretation.

An Experimental Investigation of Flow Patterns During Condensation of HFC Refrigerants in Horizontal Micro-Fin Tubes

Sanjeev Singh,Rajeev Kukreja 대한설비공학회 2019 International Journal Of Air-Conditioning and Refr Vol.27 No.1

Condensation heat transfer coefficients and flow regimes in two different horizontal micro-fin tubes are examined during the condensation of refrigerants R-134a and R-410A. The present investigation has focused on determination and prediction of condensation heat transfer coefficients and finding the interrelation between heat transfer coefficients and the prevailing flow regimes. During flow visualization, flow regimes have been captured using borosilicate glass tube at inlet and outlet of the test condenser using high speed digital camera. Stratified, stratified wavy, wavy annular, annular, slug and plug flows have been observed at different mass fluxes and vapor qualities of the refrigerants. The observed flow regimes are compared with the existing flow regime maps proposed by Breber et al. [Prediction of horizontal tube side condensation of pure components using flow regime criteria, J. Heat Transfer102 (1980) 471–476], Tandon et al. [A new flow regime map for condensation inside horizontal tubes, J. Heat Transfer104 (1982) 763–768.] and Thome et al. [Condensation in horizontal tubes, part 2: New heat transfer model based on flow regimes, Int. J. Heat Mass Transfer46 (2003) 3365–3387.] Thome et al. [Condensation in horizontal tubes, part 2: New heat transfer model based on flow regimes, Int. J. Heat Mass Transfer46 (2003) 3365–3387.] flow regime map shows good agreement with experimental data.