Anomalously high dielectric strength and low frequency dielectric relaxation of a bent-core liquid crystal with a large kink angle

Anoop Kumar Srivastava,김종윤,여성구,정진영,최이준,SINGHVIJAY,이지훈 한국물리학회 2017 Current Applied Physics Vol.17 No.6

We investigated the dielectric dispersion property of a bent-core liquid crystal (BLC) with a large kink angle in the frequency range of 1.0 Hze5.5 MHz in a planar aligned cell. Single dielectric dispersion was observed in the smectic A, nematic, and isotropic phase of the planar aligned sample. The dielectric strengths, relaxation frequencies, distribution parameters, and dc conductivity were measured as a function of temperature. The dielectric strength of the observed relaxation mode was anomalously high (~70), whereas the relaxation frequency was low at ~500 Hz. The relaxation mode observed in the planar aligned cell was attributed to the fluctuations in the polarization direction due to the cooperative motion of the molecules.

Ultra-thin platinum interfacial layer assisted-photovoltaic response of transparent Pb(Zr,Ti)O₃ thin film capacitors

Anoop, G.,Seo, Juhee,Han, Chang Jo,Lee, Hyeon Jun,Kim, Gil Woong,Lee, Sung Su,Park, Eun Young,Jo, Ji Young Elsevier 2015 SOLAR ENERGY -PHOENIX ARIZONA THEN NEW YORK- Vol.111 No.-

<P><B>Abstract</B></P> <P>For transparent solar cells, Sn:In<SUB>2</SUB>O<SUB>3</SUB>/Pb(Zr, Ti)TiO<SUB>3</SUB>/Pt(⩽5nm)/Sn:In<SUB>2</SUB>O<SUB>3</SUB> capacitor structures were fabricated using a cost-effective solution process. The insertion of ultra-thin Pt layer between the bottom Sn:In<SUB>2</SUB>O<SUB>3</SUB> electrode and Pb(Zr, Ti)TiO<SUB>3</SUB> plays a critical role in the photovoltaic characteristics of the capacitors. The Pb(Zr,Ti)O<SUB>3</SUB> capacitors with a 5nm thick Pt layer showed excellent polarization–voltage curves with reduced leakage current due to both partial (111) orientation of Pb(Zr,Ti)O<SUB>3</SUB> and alloy formation between Pt and the Sn:In<SUB>2</SUB>O<SUB>3</SUB> bottom electrode, as confirmed using X-ray photoelectron spectra analysis. The capacitors with a 5nm thick Pt layer exhibit transmittance of 45–50% in the visible light region. The current density–voltage characteristics under light illumination (AM1.5G) exhibit an open circuit voltage value of −0.62V and short circuit current density of 0.6μA/cm<SUP>2</SUP> after negative poling, with a maximum power conversion efficiency of 1.7×10<SUP>−4</SUP>%. The open circuit voltage of the capacitors with a 5nm thick Pt layer is larger with negative poling due to the higher net internal bias arising from the Schottky barrier.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Transparent Pb(Zr,Ti)O<SUB>3</SUB> (PZT) capacitors were fabricated using cost-effective solution process. </LI> <LI> Photovoltaic response was investigated by introducing ultra-thin Pt layer between bottom electrode and PZT. </LI> <LI> Introduction of Pt layer reduces the leakage current and enhances ferroelectric and PV response. </LI> <LI> The transmittance of the capacitors were 45–50% in visible region. </LI> </UL> </P>

Luminescence characteristics of Sr_1−<i>x</i>Ba_<i>x</i>Si₂O₂N₂:Eu²⁺ phosphors for white light emitting diodes

Anoop, G.,Cho, I. H.,Suh, D. W.,Yoo, J. S. WILEY‐VCH Verlag 2012 Physica status solidi. PSS. A, Applications and ma Vol.209 No.12

<P><B>Abstract</B></P><P>Sr<SUB>1−<I>x</I></SUB>Ba<SUB><I>x</I></SUB>Si<SUB>2</SUB>O<SUB>2</SUB>N<SUB>2</SUB>:Eu<SUP>2+</SUP> phosphors were synthesized using high temperature solid state reaction. The effect of Ba incorporation on the structural and luminescence characteristics of SrSi<SUB>2</SUB>O<SUB>2</SUB>N<SUB>2</SUB>:Eu<SUP>2+</SUP> phosphors were studied. The phosphors were crystallized in triclinic crystal structure and the cell volume increases monotonically with Ba addition. The PL emission peak wavelength red shifts with Ba up to <I>x</I> = 0.50 beyond which no red shift is observed. The XPS analysis shows that nitrogen is being incorporated into the host lattice along with Ba addition up to <I>x</I> = 0.50. The as synthesized phosphors show high thermal stability. Phosphor converted light emitting diodes were realized using Sr<SUB>1−<I>x</I></SUB>Ba<SUB><I>x</I></SUB>Si<SUB>2</SUB>O<SUB>2</SUB>N<SUB>2</SUB>:Eu<SUP>2+</SUP> phosphors (<I>x</I> = 0 and <I>x</I> = 0.40) showing luminance efficacies of 108 and 101 lm W<SUP>−1</SUP>. </P><P>The CIE chromaticity coordinates of Sr<SUB>1−<I>x</I></SUB>Ba<SUB><I>x</I></SUB>Si<SUB>2</SUB>O<SUB>2</SUB>N<SUB>2</SUB>:Eu (<I>x</I> = 0 and <I>x</I> = 0.40) phosphors.</P>

Emerging nano-scale delivery systems for the treatment of osteoporosis

Anoop Puthiyoth Dayanandan,조웅진,강혜민,Alvin Bacero Bello,Byoung Ju Kim,Yoshie Arai,이수홍 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Osteoporosis is a pathological condition characterized by an accelerated bone resorption rate, resulting in decreased bone density and increased susceptibility to fractures, particularly among the elderly population. While conventional treatments for osteoporosis have shown efficacy, they are associated with certain limitations, including limited drug bioavailability, non-specific administration, and the occurrence of adverse effects. In recent years, nanoparticle-based drug delivery systems have emerged as a promising approach for managing osteoporosis. Nanoparticles possess unique physicochemical properties, such as a small size, large surface area-tovolume ratio, and tunable surface characteristics, which enable them to overcome the limitations of conventional therapies. These nanoparticles offer several advantages, including enhanced drug stability, controlled release kinetics, targeted bone tissue delivery, and improved drug bioavailability. This comprehensive review aims to provide insights into the recent advancements in nanoparticle-based therapy for osteoporosis. It elucidates the various types of nanoparticles employed in this context, including silica, polymeric, solid lipid, and metallic nanoparticles, along with their specific processing techniques and inherent properties that render them suitable as potential drug carriers for osteoporosis treatment. Furthermore, this review discusses the challenges and future suggestions associated with the development and translation of nanoparticle drug delivery systems for clinical use. These challenges encompass issues such as scalability, safety assessment, and regulatory considerations. However, despite these challenges, the utilization of nanoparticle-based drug delivery systems holds immense promise in revolutionizing the field of osteoporosis management by enabling more effective and targeted therapies, ultimately leading to improved patient outcomes.

Solid-state synthesis, structure, second-harmonic generation, and luminescent properties of noncentrosymmetric BaSi7N10:Eu2+ phosphors

Anoop, G.,Lee, D.,Suh, D.,Wu, S.,Ok, K.,Yoo, J. Royal Society of Chemistry 2013 Journal of materials chemistry. C, Materials for o Vol.1 No.31

Safety and Efficacy of 6.2 mm Patellar Button in Resurfacing Less than 20 mm Thin Patella: A Matched Pair Analysis

( Anoop Jhurani ),( Piyush Agarwal ),( Mukesh Aswal ),( Purvi Saxena ),( Nidhi Singh ) 대한슬관절학회 2018 대한슬관절학회지 Vol.30 No.2

Purpose: Restoring the native patellar thickness after patellar resurfacing provides optimal function of the knee after arthroplasty and minimises complications related to the patellofemoral articulation. The aim of this study was to assess the usefulness of a thin patellar button (6.2 mm) in patients with a patella thickness of less than 20 mm during total knee arthroplasty. Materials and Methods: This is a retrospective case control study. A total of 54 female patients with an intraoperative patellar thickness of <20 mm, resurfaced with a patellar button of 6.2 mm in thickness were identified (group 1). They were matched with 54 patients with a patellar thickness of 20-23 mm, resurfaced with a patellar button of 8 mm (group 2), based on age, sex, body mass index, and deformity. A clinical and radiological evaluation was done at a minimum 2-year follow-up. Results: The preoperative mean patellar thickness was 18.94±1.07 mm and was restored to 19.06±0.79 mm in group 1, as compared to 21.63±0.99 mm and 21.72±0.99 mm in group 2. The mean postoperative range of motion was 122.22°±9.25° in group 1 and 123.52°±8.72° in group 2 (p=0.13). No patellar bone or button related complications were observed in any patient in either group. Conclusions: The 6.2 mm thin patella is useful to restore the native thickness in patients with a patellar thickness of less than 20 mm without risk of button fracture, loosening or overstuffing.

Perioperative Outcomes in 17,947 Patients Undergoing 2-Level Anterior Cervical Discectomy and Fusion Versus 1-Level Anterior Cervical Corpectomy for Treatment of Cervical Degenerative Conditions: A Propensity Score Matched National Surgical Quality Impro

Anoop R. Galivanche,Raj Gala,Preetpaul S. Bagi,Arianne J. Boylan,Christopher M. Dussik,Pedro D. Coutinho,Jonathan N. Grauer,Arya G. Varthi 대한척추신경외과학회 2020 Neurospine Vol.17 No.4

Objective: To compare the perioperative morbidity of 2-level anterior cervical discectomy and fusion (ACDF) with that of 1-level anterior cervical corpectomy and fusion (ACCF) for the treatment of cervical degenerative conditions. Methods: A retrospective study of the 2005–2016 National Surgical Quality Improvement Program database for patients undergoing 2-level ACDF and 1-level ACCF was performed. Patient data included: age, sex, body mass index (BMI), functional status, and American Society of Anesthesiologists (ASA) physical status (PS) classification. Hospital data included: operative time and length of hospital stay (LOS). Thirty-day outcome data included: any, serious, and minor adverse events, return to the operating room, readmission, and mortality. After propensity matching for age, sex, ASA PS classification, functional status, and BMI, multivariate logistic regression analysis was used to compare outcomes between the 2 propensity-matched subcohorts. Finally, multivariate logistic regression that additionally controlled for operative time was performed to compare the 2 propensity-matched subcohorts. Results: A total of 17,497 cases were identified, with 90.20% undergoing 2-level ACDF and 9.80% undergoing 1-level ACCF. Patients undergoing 2-level ACDF were younger, more likely to be female, had higher functional status, and had shorter operative time and LOS (p<0.001). After propensity score matching, cases undergoing 1-level ACCF had a statistically significant higher rate of serious adverse events (p=0.005). This difference was no longer significant after controlling for operative time. Conclusion: While there was noted to be additional morbidity in 1-level ACCF cases relative to 2-level ACDF cases, the lack of difference once controlling for the surgical time supports using the procedure that best accomplishes the surgical objectives.

Phenylbutazone의 란탄(III) 착물에 대한 합성, 스펙트럼 및 열적 연구

Anoop, M.R.,Binil, P.S.,Jisha, K.R.,Suma, S.,Sudarsanakumar, M.R. 대한화학회 2011 대한화학회지 Vol.55 No.4

1,2-diphenyl-4-butyl-3,5-pyrazolidinedione(phenylbutazone, PB)의 란탄(III) 착물을 합성하여 원소분석, 몰전기전도도 측정, IR, UV-Vis. 및 NMR 스펙트럼으로 특성을 조사하였다. 스펙트럼 데이터로부터 PB가 pyrazolidinedione 고리의 두 카르보닐 산소를 통해 이배위 및 일이온화 리간드로 배위됨을 규명하였다. 몰전기전도도 데이터로부터 이들 착물이 비전해질임을 규명하였다. 이들 착물의 열적 행동을 공기 중에서 TG 및 DTG로 연구한 결과, 탈수화, 열적 안전성 및 열분해에 관한 정보를 얻을 수 있었다. 최종 생성물은 해당 금속의 산화물로 밝혀졌다. 탈수화 및 분해 단계에 대한 열역학 및 반응속도 파라메터를 구하였다. 분해 단계에 대한 음의 엔트로피 값은 반응물보다 활성화 착물이 더 질서있는 구조를 갖는다는 것을 의미하며, 이때 반응은 정상보다 느렸다. 이러한 연구를 바탕으로 착물의 분자식이 $[Ln(PB)_3]{\cdot}5H_2O$(Ln=La 및 Ce) 그리고 $[Ln(PB)_3 (H_2O)_2]{\cdot}2H_2O$(Ln=Pr, Nd 및 Sm)임을 규명하였다. Lanthanide(III) complexes of 1,2-diphenyl-4-butyl-3,5-pyrazolidinedione(phenylbutazone, PB) have been synthesized and characterized by elemental analyses, molar conductance measurements, IR, UV-Vis. and NMR spectra. The spectral data reveal that the PB acts as a bidentate and mono-ionic ligand coordinating through both the carbonyl oxygens of the pyrazolidinedione ring. The molar conductance data suggest that the complexes are non-electrolytes. The thermal behaviour of the complexes was studied by TG and DTG in air atmosphere and the results provide information about dehydration, thermal stability and thermal decomposition. The final products are found to be the corresponding metal oxides. The thermodynamic parameters and kinetic parameters were evaluated for the dehydration and decomposition stages. The negative entropy values of the decomposition stages indicate that the activated complexes have a more ordered structure than the reactants and that the reactions are slower than normal. Based on these studies, the complexes have been formulated as $[Ln(PB)_3]{\cdot}5H_2O$(Ln=La and Ce) and $[Ln(PB)_3(H_2O)_2]{\cdot}2H_2O$(Ln=Pr, Nd and Sm).

Effect of Closed Suction Drain on Blood Loss and Transfusion Rates in Simultaneous Bilateral Total Knee Arthroplasty: A Prospective Randomized Study

( Anoop Jhurani ),( Gautam M. Shetty ),( Vinay Gupta ),( Purvi Saxena B. Tech ),( Nidhi Singh M. Pharm ) 대한슬관절학회 2016 대한슬관절학회지 Vol.28 No.3

Purpose: Simultaneous bilateral total knee arthroplasty (TKA) is associated with excessive blood loss and morbidity arising from postoperative reduction in hemoglobin (Hb). The purpose of this prospective randomized study was to determine if drains have any effect on blood loss, postoperative reduction in Hb levels and transfusion rates compared to no drainage in simultaneous bilateral TKAs. Materials and Methods: Two hundred and thirty patients who underwent simultaneous bilateral TKA by a single surgeon were randomly allotted to drain or no-drain group (n=115 in each group). Postoperative Hb level, blood loss volume and transfusion rate were compared between the two groups. Results: The mean postoperative Hb level (p=0.38), blood loss volume (p=0.33) and transfusion rate (p=0.52) in the drain group were not significantly different compared to the no-drain group. No statistical difference was found in terms of complications, readmissions and mortality rates between the two groups. Conclusions: No significant difference was observed in the two groups with respect to blood loss and blood transfusion. Non-drainage does not offer an advantage over drainage with respect to conserving blood in simultaneous bilateral TKA.

Could We Prevent Displacing the Undisplaced Fracture Neck of Femur?

Anoop C. Dhamangaonkar 대한정형외과학회 2012 Clinics in Orthopedic Surgery Vol.4 No.2