Synthesis and Magnetic Relaxation Properties of Paramagnetic Gd-complexes of New DTPA-bis-amides. The X-ray Crystal Structure of [Gd(L)(H₂O)]·3H₂O (L = DTPA-bis(4-carboxylicphenyl)amide)

Dutta, Sujit,Kim, Suk-Kyung,Lee, Eun-Jung,Kim, Tae-Jeong,Kang, Duk-Sik,Chang, Yong-min,Kang, Sang-Ook,Han, Won-Sik Korean Chemical Society 2006 Bulletin of the Korean Chemical Society Vol.27 No.7

A new type of DTPA-bis-amides (L1-L4) and their Gd(III)-complexes of the type $[Gd(L)(H_2O)]{\cdot}nH_2O$ (5: L1; 6: L2; 7: L3; 8: L4) have been prepared and characterized by analytical and spectroscopic techniques. The X-ray crystal structure of 8 has been determined for structural confirmation. The coordination geometry adopts a tricapped trigonal prism geometry with L4 acting as a chelate octadentate and a water molecule in the coordination sphere. Crystals are monoclinic, $P2_1$, a = 14.468(3), b = 19.235(4), c = 13.527(2) $\AA$ $\beta$ = $107.245(3)^{\circ}$, V = 3595.2(11) $\AA^3$, Z = 4, $D_{calc}$ = 1.570. Significant increases in relaxivities are observed with 6 and 7 as compared with that of $Omniscan^{(R)}$, a commercial MR agent: R1 = 12.46 $mM^{-1}\;s^{-1}$, R2 = 8.76 $mM^{-1}\;s^{-1}$ for 6; R1 = 12.77 nm-1 s-1, R2 = 7.60 mM-1 s-1 for 7; R1 = 4.9 $mM^{-1}\;s^{-1}$, R2 = 4.8 $mm^{-1}\;s^{-1}$ for $Omniscan^{(R)}$. In the case of 5, however, both R1 and R2 are found to be lower to show 2.09 $mM^{-1}\;s^{-1}$, and 1.82 $mM^{-1}\;s^{-1}$, respectively.

Synthesis and Magnetic Relaxation Properties of Paramagnetic Gd-complexes of New DTPA-bis-amides. The X-ray Crystal Structure of [Gd(L)(H2O)]?H2O (L = DTPA-bis(4-carboxylicphenyl)amide)

Sujit Dutta,Suk-Kyung Kim,Eun Jung Lee,Tae-Jeong Kim*,Duk-Sik Kang,Yongmin Chang*,Sang Ook Kang,Won-Sik Han 대한화학회 2006 Bulletin of the Korean Chemical Society Vol.27 No.7

A new approach to working coil design for a high frequency full bridge series resonant inverter fitted contactless induction heater

Dhar, Sujit,Dutta, Biswajit,Ghoshroy, Debasmita,Roy, Debabrata,Sadhu, Pradip Kumar,Ganguly, Ankur,Sanyal, Amar Nath,Das, Soumya Techno-Press 2017 Advances in computational design Vol.2 No.4

High frequency full bridge series resonant inverters have become increasingly popular among power supply designers. One of the most important parameter for a High Frequency Full Bridge Series Resonant Inverter is optimal coil design. The optimal coil designing procedure is not a easy task. This paper deals with the New Approach to Optimal Design Procedure for a Real-time High Frequency Full Bridge Series Resonant Inverter in Induction Heating Equipment devices. A new design to experimental modelling of the physical properties and a practical power input simulation process for the non-sinusoidal input waveform is accepted. The design sensitivity analysis with Levenberg-Marquardt technique is used for the optimal design process. The proposed technique is applied to an Induction Heating Equipment devices model and the result is verified by real-time experiment. The main advantages of this design technique is to achieve more accurate temperature control with a huge amount of power saving.

DTPA-bis(4-carboxycyclohexyl)amide 상자성 복합체의 자기이완특성에 관한 연구

김인성,이영주,이재준,김주현,김유경,Dutta Sujit,김숙경,김태정,장용민,강덕식 대한자기공명의과학회 2006 Investigative Magnetic Resonance Imaging Vol.10 No.1

Purpose : To evaluate the NMR relaxation properties of newly developed high performance paramagnetic complexes. Materials and methods : 4-aminomethylcyclohexane carboxylic acid (0.63 g, 4 mmol) was mixed with the suspension solution of DMF (15 mL) and DTPA-bis-anhydride (0.71 g, 2 mmol) to synthesize the ligand. The ligand was then mixed with Gd2O3 (0.18 g, 0.5 mmol) to synthesize Gd-chelate. For the measurement of magnetic relaxivity of paramagnetic compounds, the compounds were diluted to 1mM and then the relaxation times were measured at 1.5T(64 MHz). Inversion-recovery pulse sequence was employed for T1 relaxation measurement and CPMG(Carr-Purcell-Meiboon-Gill) pulse sequence was employed for T2 relaxation measurement. Using MATLAB(Version 7.1) program, T1 magnetic relaxation map, R1 map, T2 magnetic relaxation map and R2 map were developed to represent magnetic relaxation time and magnetic relaxivity as image. Results : Compared to R1=4.9 mM-1sec-1 and R2= 4.8 mM-1sec-1 of Omniscan (Gadodiamide), which is commercially available paramagnetic MR agent, R1 of SUK090(Gd-C32H74N5O24) was 12.46 mM-1sec-1 and R1 of SUK091(Gd-C34H78N5O24) was 12.77 mM-1sec-1. However, R1 of SUK092(Gd-C30H56N5O17) was decreased to 2.09 mM-1sec-1. In case of R2, SUK090(Gd-C32H74N5O24) was 8.76 mM-1sec-1 and SUK091(Gd-C34H78N5O24) was 7.60 mM-1sec-1 whereas SUK092(Gd-C30H56N5O17) was decreased to 1.82 mM-1sec-1. Conclusion : Among three new paramagnetic complexes, SUK090(Gd-C32H74N5O24) and SUK091(Gd- C34H78N5O24) showed higher T1, T2 magnetic relaxation rates than that of commercially available paramagnetic MR agent and thus expected to have more contrast enhancement effect. 목적 : 새로 개발한 상자성 복합체의 자기이완 특성을 조사해 보고자 하였다. 대상 및 방법 : DMF(15 mL)와 DTPA-bis-anhydride(0.71 g, 2 mmol)의 서스펜션 용액에 4-aminomethylcyclohexane carboxylic acid(0.63g, 4 mmol)를 넣어 리간드를 합성한 후 Gd2O3(0.18 g, 0.5 mmol)을 넣어 최종적인 Gd 착화물을 합성하였다. 상자성 복합체의 자기이완율을 측정하기 위해 상자성 복합체를 3차 증류수를 사용하여 1 mM로 희석시켰으며 1.5T(64 MHz)에서 자기이완 시간을 측정하였다. T1 자기이완시간을 측정하기 위하여 반전 회복(inversion-recovery) 펄스열을 사용하였으며 T2 자기이완시간은 CPMG(Carr-Purcell-Meiboon-Gill) 펄스열을 사용하였다. 자기이완 시간 및 자기이완율을 영상으로 표현한 T1 자기이완 지도, R1 지도, T2 자기이완 지도 및 R2 지도를 구현 하였다. 결과 : 현재 시판중인 상자성 조영제인 Omniscan(Gadodiamide)의 R1 = 4.9 mM-1sec-1, R2 = 4.8 mM-1sec-1에 비해 R1의 경우 SUK090(Gd-C32H74N5O24)는 12.46 mM-1sec-1, SUK091(Gd-C34H78N5O24)는 12.77 mM-1sec-1의 값을 나타낸 반면 SUK092(Gd- C30H56N5O17)는 2.09 mM-1sec-1로 자기이완율이 감소하였다. R2의 경우 SUK090(Gd-C32H74N5O24)는 8.76 mM-1sec-1, SUK091(Gd-C34H78N5O24)는 7.60 mM-1sec-1의 값을 나타낸 반면 SUK092(Gd-C30H56N5O17)는 1.82 mM-1sec-1로 감소 하였다. 결론 : 본 연구에서 합성한 상자성 복합체중 SUK090(Gd-C32H74N5O24)와 SUK091(Gd-C34H78N5O24)는 기존의 상자성 조영제에 비해 T1, T2 자기이완율이 크고 결과적으로 T1/T2 조영증강 효과가 클 것으로 예상된다.

Use of oral cholera vaccine as a vaccine probe to define the geographical dimensions of person-to-person transmission of cholera

Ali, Mohammad,Kim, Deok Ryun,Kanungo, Suman,Sur, Dipika,Manna, Byomkesh,Digilio, Laura,Dutta, Shanta,Marks, Florian,Bhattacharya, Sujit K.,Clemens, John Elsevier 2018 INTERNATIONAL JOURNAL OF INFECTIOUS DISEASES Vol.66 No.-

<P><B>Abstract</B></P> <P><B>Background</B></P> <P>Cholera is known to be transmitted from person to person, and inactivated oral cholera vaccines (OCVs) have been shown to confer herd protection via interruption of this transmission. However, the geographic dimensions of chains of person-to-person transmission of cholera are uncertain. The ability of OCVs to confer herd protection was used to define these dimensions in two cholera-endemic settings, one in rural Bangladesh and the other in urban India.</P> <P><B>Methods</B></P> <P>Two large randomized, placebo-controlled trials of inactivated OCVs, one in rural Matlab, Bangladesh and the other in urban Kolkata, India, were reanalyzed. Vaccine herd protection was evaluated by relating the risk of cholera in placebo recipients to vaccine coverage of surrounding residents residing within concentric rings. In Matlab, concentric rings in 100-m increments up to 700m were evaluated; in Kolkata, 50-m increments up to 350m were evaluated.</P> <P><B>Results</B></P> <P>One hundred and eight cholera cases among 24667 placebo recipients were detected during 1year of post-vaccination follow-up at Matlab; 128 cholera cases among 34968 placebo recipients were detected during 3 years of follow-up in Kolkata. Consistent inverse relationships were observed between vaccine coverage of the ring and the risk of cholera in the central placebo recipient for rings with radii up to 500m in Matlab and up to 150m in Kolkata.</P> <P><B>Conclusions</B></P> <P>These results suggest that the dimensions of chains of person-to-person transmission in endemic settings can be quite large and may differ substantially from setting to setting. Using OCVs as ‘probes’ to define these dimensions can inform geographical targeting strategies for the deployment of these vaccines in endemic settings.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Cholera, a waterborne disease, is known to be transmitted from person to person. </LI> <LI> However, the geographical dimensions of this transmission are uncertain. </LI> <LI> Oral cholera vaccines were used as probes to define these dimensions. </LI> <LI> Dimensions were 500m in rural Bangladesh and 150m in Kolkata, India. </LI> <LI> Person-to-person transmission of cholera can be sustained over long distances. </LI> </UL> </P>

상자성 복합체의 분자량에 따른 T1 및 T2 자기이완시간에 관한 연구

김인성,이영주,김주현,김숙경,김태정,강덕식,장용민,Kim In-Sung,Lee Young-Ju,Kim Ju-Hyun,Sujit Dutta,Kim Suk-Kyung,Kim Tae-Jeong,Kang Duk-Sik,Chang Yong-Min 한국의학물리학회 2006 의학물리 Vol.17 No.2

상자성 복합체의 분자량에 따른 물분자의 T1 및 T2 자기이완 특성을 조사해 보고자 하였다. DMF (15 ml)와 DTPA-bis-anhydride (0.71 g, 2 mmol) 용액에 4-aminomethylcyclohexane carboxyilc acid를 넣어 리간드를 합성한 후 $Gd_2O_3$ (0.18g, 0.5 mmol)을 넣어 최종적인 Gd 착화물을 합성하였다. 상자성 복합체의 자기이완율을 측정하기 위해 상자성 복합체를 3차 증류수를 사용하여 1 mM로 희석시켰으며 1.5T(64 MHz)에서 자기이완 시간을 측정하였다. T1 자기이완시간을 측정하기 위하여 반전 회복(Inversion-recovery) 펄스열을 사용하였다. 반전 회복 펄스열의 경우 반전시간(Inversion time, T1)은 50 msec에서부터 최대 1,750 msec까지 총 35개의 반전시간에서 영상을 획득하였다. T2 자기이완시간은 CPMG(Carr-Purcell-Meiboon-Gill) 펄스열을 사용하였다. 자기이완 시간을 구하기 위해 각각의 샘플에 관심영역(region of Interest)을 설정하여 영상의 신호강도를 측정한 후 비선형 곡선 맞춤을 실행하여 T1 및 T2값을 얻어낸 후, 이를 통해서 R1 및 R2를 계산하였다. 분자량이 587 달톤인 Omniscan의 1.5T에서의 T1, T2값이($205.1{\pm}2.57$) msec, ($209.4{\pm}4.28$) msec 임에 비해 새로이 합성된 상자성 Gd 화합물의 경우 모두 T1, T2값이 T1의 경우 분자량에 따라 $(96.35{\pm}2.04)-(79.38{\pm}1.55)$ msec, T2의 경우 $(91.02{\pm}2.08)-(76.66{\pm}1.84)$ msec로 감소한 결과를 얻었다. 새로이 합성된 Gd 화합물 간에도 분자량에 따라 R1 및 R2값이 증가하는 경향을 나타내었다. 상자성 복합체의 분자량이 증가함에 따라 T1 및 T2 자기이완 시간이 단축되고 결과적으로 자기이완율 R1, R2가 분자량에 비례하여 증가하였다. To evaluate the T1, T2 magnetic relaxation properties of water molecule according to molecular weight of paramagnetic complex. 4-aminomethyicyclohexane carboxylic acid (0.63 g, 4 mmol) was mixed with the suspension solution of DMF (15 ml) and DTPA-bis-anhydride (0.71 g, 2 mmol) to synthesize the ligand. The ligand was then mixed with $Gd_2O_3$ (0.18 g, 0.5 mmol) to synthesize Gd-chelate. For the measurement of magnetic relaxivity of paramagnetic compounds, the compounds were diluted to 1 mM and then the relaxation times were measured at 1.57 (64 MHz). Inversion-recovery pulse sequence was employed for T1 relaxation measurement and CPMG (Carr-Purcell-Meiboon-Gill) pulse sequence was employed for T2 relaxation measurement. In case of inversion recovery sequence, total 35 images with different inversion time(T1)s ranging from 50 msec to 1,750 msec. To estimate the relaxation times, the signal intensity of each sample was measured using region of Interest (ROI) and then fitted by non-linear least square method to yield T1, T2 relaxation times and also R1 and R2. Compared to T1=($205.1{\pm}2.57$) msec and T2=($209.4{\pm}4.28$) msec of Omniscan (Gadodiamide), which is commercially available paramagnetic MR agent, T1 and T2 values of new paramagnetic complexes were reduced along with their molecular weight. That is, T1 value was ranged from $(96.35{\pm}2.04)\;to\;(79.38{\pm}1.55)$ msec and T2 value was ranged from $(91.02{\pm}2.08)\;to\;(76.66{\pm}1.84)$ msec. Among new paramagnetic complexes, there is a tendency that the R1 and R2 increase as the molecular weight is increases. As molecular weight of paramagnetic complex increases, T1 and T2 relaxation times reduce and thus the increase of relaxivity (R1 and R2) Is proportional to molecular weight.