Mapping brain glucose uptake with chemical exchange-sensitive spin-lock magnetic resonance imaging

Jin, Tao,Mehrens, Hunter,Hendrich, Kristy S,Kim, Seong-Gi Nature Publishing Group 2014 Journal of cerebral blood flow and metabolism Vol.34 No.8

<P>Uptake of administered D-glucose (Glc) or 2-deoxy-D-glucose (2DG) has been indirectly mapped through the chemical exchange (CE) between glucose hydroxyl and water protons using CE-dependent saturation transfer (glucoCEST) magnetic resonance imaging (MRI). We propose an alternative technique—on-resonance CE-sensitive <I>spin-lock</I> (CESL) MRI—to enhance responses to glucose changes. Phantom data and simulations suggest higher sensitivity for this ‘glucoCESL' technique (versus glucoCEST) in the intermediate CE regime relevant to glucose. Simulations of CESL signals also show insensitivity to <I>B</I><SUB>0</SUB>-fluctuations. Several findings are apparent from <I>in vivo</I> glucoCESL studies of rat brain at 9.4 Tesla with intravenous injections. First, dose-dependent responses are nearly linearly for 0.25-, 0.5-, and 1-g/kg Glc administration (obtained with 12-second temporal resolution), with changes robustly detected for all doses. Second, responses at a matched dose of 1 g/kg are much larger and persist for a longer duration for 2DG versus Glc administration, and are minimal for mannitol as an osmolality control. And third, with similar increases in steady-state blood glucose levels, glucoCESL responses are ∼2.2 times higher for 2DG versus Glc, consistent with their different metabolic properties. Overall, we show that glucoCESL MRI could be a highly sensitive and quantifiable tool for glucose transport and metabolism studies.</P>

Enhancing sensitivity of pH-weighted MRI with combination of amide and guanidyl CEST

Jin, Tao,Wang, Ping,Hitchens, T. Kevin,Kim, Seong-Gi Elsevier 2017 NeuroImage Vol.157 No.-

<P><B>Abstract</B></P> <P>Amide-proton-transfer weighted (APTw) MRI has emerged as a non-invasive pH-weighted imaging technique for studies of several diseases such as ischemic stroke. However, its pH-sensitivity is relatively low, limiting its capability to detect small pH changes. In this work, computer simulations, protamine phantom experiments, and in vivo gas challenge and experimental stroke in rats showed that, with judicious selection of the saturation pulse power, the amide-CEST at 3.6ppm and guanidyl-CEST signals at 2.0ppm changed in opposite directions with decreased pH. Thus, the difference between amide-CEST and guanidyl-CEST can enhance the pH measurement sensitivity, and is dubbed as pH<SUB>enh</SUB>. Acidification induced a negative contrast in APTw, but a positive contrast in pH<SUB>enh</SUB>. In vivo experiments showed that pH<SUB>enh</SUB> can detect hypercapnia-induced acidosis with about 3-times higher sensitivity than APTw. Also, pH<SUB>enh</SUB> slightly reduced gray and white matter contrast compared to APTw. In stroke animals, the CEST contrast between the ipsilateral ischemic core and contralateral normal tissue was −1.85 ± 0.42% for APTw and 3.04 ± 0.61% (n = 5) for pH<SUB>enh</SUB>, and the contrast to noise was 2.9 times higher for pH<SUB>enh</SUB> than APTw. Our results suggest that pH<SUB>enh</SUB> can be a useful tool for non-invasive pH-weighted imaging.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The pH<SUB>enh</SUB> MRI combines the amide- and guanidyl-CEST effects to enhance the pH-sensitivity. </LI> <LI> With B<SUB>1</SUB>-tuning, acidosis induce a negative and a positive contrast for the amide- and guanidyl-CEST signal, respectively. </LI> <LI> In pH<SUB>enh</SUB>, the RF powers are also adjusted to match the direct water saturation at amide and guanidyl frequencies. </LI> <LI> Phantom and in vivo studies confirm a higher pH-sensitivity for pH<SUB>enh</SUB> over APT-weighted MRI. </LI> </UL> </P>

Thermal Shock Behaviors of AlN/BN Laminated Ceramic Composites

Tao Zhang,Ji-feng Zhao,Zhi-hao Jin,Hai-yun Jin 한양대학교 세라믹연구소 2009 Journal of Ceramic Processing Research Vol.10 No.2

AlN/BN laminated ceramic composites were fabricated by a flow casting method. The thermal shock behavior of both block AlN ceramics and AlN/BN laminated ceramic composites were carried out for comparison. To understanding the different of thermal shock resistance for the two materials, the microstructures were observed and the mechanical properties were tested. The results showed that, the thermal shock resistance of AlN/BN laminated ceramic composites was larger than that of block AlN ceramics. During the tests of residual strength after quenching from different temperatures, for the block AlN ceramics, the residual strength would decrease rapidly when the critical temperature difference ΔTc was larger than 450℃, on the other hand, for the AlN/BN laminated ceramic composites, the residual strength would decrease slowly and there was no obvious ΔTc. AlN/BN laminated ceramic composites were fabricated by a flow casting method. The thermal shock behavior of both block AlN ceramics and AlN/BN laminated ceramic composites were carried out for comparison. To understanding the different of thermal shock resistance for the two materials, the microstructures were observed and the mechanical properties were tested. The results showed that, the thermal shock resistance of AlN/BN laminated ceramic composites was larger than that of block AlN ceramics. During the tests of residual strength after quenching from different temperatures, for the block AlN ceramics, the residual strength would decrease rapidly when the critical temperature difference ΔTc was larger than 450℃, on the other hand, for the AlN/BN laminated ceramic composites, the residual strength would decrease slowly and there was no obvious ΔTc.

An investigation of the mechanical property and thermal shock behavior of machinable B₄C/BN ceramic composites

Tao Jiang,Haiyun Jin,Zhihao Jin,Jianfeng Yang,Guanjun Qiao 한양대학교 세라믹연구소 2009 Journal of Ceramic Processing Research Vol.10 No.1

Machinable B₄C/BN ceramic composites were fabricated by a hot-pressing process at 1,850 ℃ for 1 h under a pressure of 30MPa. In this article, the mechanical property, thermal shock behavior and machinability of the B₄C/BN ceramic composites were investigated. The fracture strength and fracture toughness of B₄C/BN nanocomposites were significantly improved in comparison with B₄C/BN microcomposites. The Vickers hardness of B₄C/BN nanocomposites and B₄C/BN microcomposites decreased gradually with an increase in the content of h-BN, while the machinability of B₄C/BN nanocomposites and B₄C/BN microcomposites were significantly improved. The B₄C/BN ceramic composites with an h-BN content of more than 20 wt% exhibited excellent machinability. The thermal shock resistance of the B₄C/BN ceramic composites was much better than that of the B₄C monolith, and the thermal shock resistance of B₄C/BN nanocomposites was much better than that of B₄C/BN microcomposites. The thermal shock temperature difference (ΔTc) of the B₄C monolith was about 300℃, while the ΔTc of B₄C/BN microcomposites was about 500℃ and the ΔTc of B₄C/BN nanocomposites was about 600℃. Machinable B₄C/BN ceramic composites were fabricated by a hot-pressing process at 1,850 ℃ for 1 h under a pressure of 30MPa. In this article, the mechanical property, thermal shock behavior and machinability of the B₄C/BN ceramic composites were investigated. The fracture strength and fracture toughness of B₄C/BN nanocomposites were significantly improved in comparison with B₄C/BN microcomposites. The Vickers hardness of B₄C/BN nanocomposites and B₄C/BN microcomposites decreased gradually with an increase in the content of h-BN, while the machinability of B₄C/BN nanocomposites and B₄C/BN microcomposites were significantly improved. The B₄C/BN ceramic composites with an h-BN content of more than 20 wt% exhibited excellent machinability. The thermal shock resistance of the B₄C/BN ceramic composites was much better than that of the B₄C monolith, and the thermal shock resistance of B₄C/BN nanocomposites was much better than that of B₄C/BN microcomposites. The thermal shock temperature difference (ΔTc) of the B₄C monolith was about 300℃, while the ΔTc of B₄C/BN microcomposites was about 500℃ and the ΔTc of B₄C/BN nanocomposites was about 600℃.

Effect of Sorbitol on In Vitro Porcine Oocyte Maturation and Subsequent Developmental after Parthenogenetic Activation

Tao Lin,Jin-Yu Zhang,Yun-Fei Diao,Min-Gu Lee,Rong-Xun Han,Reze K. Oqani,Dong-Il Jin 한국동물번식학회 2012 Reproductive & Developmental Biology(Supplement) Vol.36 No.2s

The objective of the present study was to investigate the effects of different concentrations of sorbitol supplementation for in vitro maturation medium and in vitro culture medium, on porcine cumulus oocyte complexe(COC) maturation and subsequent developmental capacity after parthenogenetic activation. Porcine COC were cultured for 44 h(0~ 22 h termed MI stage and 22~44 h termed MII stage) in TCM199 without(- ) or with(+) sorbitol (20 μM, 100 μM, 200 μM), and the resultant metaphase II oocytes cultured in PZM-3 for 7 days following activation. Our results showed that supplementation with appropriate concentrations of sorbitol (20 μM) during full term maturation culture(MI+/MII+) significantly(p<0.05) improved blastocyst formation rates and total cell number. When the concentration of sorbitol were increased to 100 μM and 200 μM during maturation culture, the maturation rate of COC were significantly reduced compared with 20 μΜ or control groups. Also blastocyst formation rates significantly(p<0.05) reduced with increasing concentration of sorbitol(200 μM). Supplementation with sorbitol(20 μM, 50 μM, 100 μM) into PZM-3 for in vitro culture significantly(p<0.05) inhibited blastocyst formation compared with control group. However, the blastocyst formation rates start to rise again when 50 μ M sorbitol was used for the first 48 hours and then cultured in PZM-3 without sorbitol. There was no significant difference in cell number between control and sorbitol treated groups. When the activated oocytes were cultured in PZM-3 for 48h and then cultured in PZM-3 with sorbitol, interestingly, the blastocyst formation rate was similar to that of PZM-3 with sorbitol for in vitro culture and significantly lower than control group. These results suggest that addition of low concentrations of sorbitol(20 μM) during oocyte maturation is beneficial for subsequent blastocyst development and improved embryo quality. However, treatment with sorbitol supplementation during in vitro culture medium is negative effect to blastocyst formation.

Effect of Sorbitol on In Vitro Porcine Oocyte Maturation and Subsequent Developmental after Parthenogenetic Activation

Tao Lin,Jin-Yu Zhang,Yun-Fei Diao,Min-Gu Lee,Rong-Xun Han,Reze K. Oqani,Dong-Il Jin 한국동물번식학회 2012 Reproductive & developmental biology Vol.36 No.2

Study on enhancing the efficiency of electricity generation and removal of Cr(VI) by photocatalysis coupled with microbial fuel cells (MFCs) system

Tao JIN,Xia HU 대한환경공학회 2019 대한환경공학회 학술발표논문집 Vol.2019 No.-

The “Mahāyāna” in the Awakening of Faith in Mahāyāna : Its Meaning and Use, and the Confusion thereof

Tao Jin 금강대학교 불교문화연구소 2017 불교학 리뷰 Vol.22 No.-

이 논문은 <<대승기신론>>, 특히 대의장인 「입의분(立義分)」에서 ‘대승(mahāyāna)’이라는 단어 해석에 초점을 맞췄다. 일반적으로 많은 현대 학자들은 “대승”이라는 단어는 (소승불교에 대응하는) ‘대승(Mahāyāna)’ 불교라기 보다는 소위 ‘일심’으로 이해해 왔다. 즉, 진여로서 그리고 현상으로서 동시에 존재하는 마음으로, 이런 의미에서 정적인 상태나 동적인 상태 모두에서 이중적인 절대성으로 이해되어왔다. 논이 그것 자체로 ‘대승’불교의 가르침이 되어야 한다고 주장하는 것은 몇몇 학자들에 의해 ‘대승’이라고 이름붙여진 ‘일심’에 대한 이러한 설명 때문이다. 이 논문은 ‘대승’을 이와 같이 ‘절대적’으로 읽는 것을 반박하고자 한다. <<대승기신론>>에서 ‘대승’이라는 단어는지속적으로 그리고 배타적으로 ‘대승’불교 또는 그것의 가르침을 가리킨다는 것을 논증한다. 그 ‘대승’이라는 단어가 대의장인 「입의분」에서 각각‘큼’과 ‘수레’로서 절대적인 것으로 특징지어지고 비유하는데사용되었고, 그렇게 함으로써, ‘대승’으로서 ‘대승’불교를 실현하고 숭상하는데 사용되었다는 것을 논증한다. 그리고 ‘대승’이라는 단어의 의미와 사용의 혼동이 ‘대승’을 절대적인 것으로 읽는 현대적 읽기를 초래했음을 논증하고자 한다. This paper is focused on the reading of the word “mahāyāna” in the Awakening of Faith in Mahāyāna (or Qixinlun in its popular Chinese abbreviation), particularly in its synoptic chapter, namely, the Liyi fen (立義 分). To many modern scholars, it refers not to the “Mahāyāna” or “Great Vehicle” Buddhism (as opposed to the “Hīnayāna” or “Lesser Vehicle” Buddhism) as it is popularly understood, but to the so-called “One Mind” (yixin 一心), a mind that exists simultaneously as Suchness and Phenomena and constitutes in that sense a dual-natured Absolute in both its quiescence and dynamicity. It is for this presentation of the “One Mind”, labelled “Mahāyāna” by some, that the treatise claims itself to be the teaching of the “Mahāyāna” Buddhism. This paper proposes to dispute this “Absolute” reading of “mahāyāna”. It argues that the word “mahāyāna” in Qixinlun refers consistently and exclusively to (and in that sense means) the “Mahāyāna” Buddhism or its teaching; that the word is used in the synoptic chapter of the Liyi to respectively characterize and metaphorize the Absolute as “great” (i.e., “mahā”) and “vehicle” (i.e., “yāna”) and, in doing so, to praise and glorify “Mahāyāna” Buddhism as a “great vehicle” and thus a superior teaching; and that the confusion of the meaning and the use of the word results in the modern reading of “mahāyāna” as the Absolute.

Synthesis of g-C3N4/CQDs composite and its photocatalytic degradation property for Rhodamine B

Jin Tao,Liu Chengbao,Chen Feng,Qian Junchao,Qiu Yongbin,Meng Xianrong,Chen Zhigang 한국탄소학회 2022 Carbon Letters Vol.32 No.6

To solve the problem of water pollution, researchers have proposed a photocatalytic degradation technology, in which the key factor is the development of efficient photocatalytic materials. Graphitic carbon nitride (g-C3N4), an n-type semiconductor, has been widely studied due to its suitable band gap (2.7 eV), low cost, easy preparation, non-toxicity, and high photostability. However, the pure-phase g-C3N4 still has defects such as low specific surface area, insufficient visible light absorption, low charge mobility, few active sites for interfacial reaction, and easy recombination of photogenerated electron–hole pairs, which leads to the lower photocatalytic activity of g-C3N4. Aiming at the problems mentioned above, this paper focus on the synthesis of g-C3N4-based composites with high photocatalytic activity via lemon juice induction method. Thiourea and lemon juice were selected as precursors, and carbon quantum dots (CQDs) as electron mediators were introduced anchoring on the surface of g-C3N4 to build g-C3N4/CQDs with compact interface. The results showed that small-sized CQDs are uniformly distributed on the surface of g-C3N4, and the g-C3N4/CQDs composite has a 2D0D structure, which reduces the recombination of photogenerated electron–hole pairs. The photocatalytic degradation efficiency of 4% g-C3N4/CQDs for RhB reaches the highest data of 90.9%, and the photocatalytic degradation rate is 0.016 min−1, which is about 2.3 times that of g-C3N4. After four cycles of photocatalytic reaction, the photocatalytic degradation efficiency of the material remained at 81.7%. Therefore, the g-C3N4/CQDs synthesized via lemon juice induction has a more stable microstructure, and the charge separation efficiency is greatly improved, which is suitable for practical photocatalytic environmental protection.

Host performance of Trichogramma species on Opisina arenosella, and evaluation of their biological control efficacy

Tao Jin,Yuying Lin,Shichou Han,Guangchang Ma,Haibo Wen,Zhengqiang Peng 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.3

Five candidate species for biocontrol of Opisina arenosella Walker, a destructive pest of palm trees, were evaluated. To compare host performance, 5 Trichogramma species were allowed to parasitize O. arenosella eggs of different ages and egg densities. The parasitization capacity of two species, T. embryophagum and T. japonicum, were evaluated with respect to adult age. Treatments consisted of field with releases of T. embryophagum or T. japonicum set up in Danzhou, Hainan, and the pest densities was recorded periodically. The results showed that T. embryophagum, T. chilonis, and T. dendrolimi had a strong parasitic ability on 0-day-old O. arenosella eggs. In species comparisons, the parasitism rates of T. embryophagum on 1-day-old and 4-day-old eggs, and T. japonicum on 2-day-old, 3-day-old, and 5-day-old eggs of O. arenosella were significantly higher than those of other Trichogramma species. At densities of 40 and 35 eggs/tube (84.8 cm 3 ), the numbers of eggs parasitized by T. embryophagum and T. japonicum were the highest, at 29.9 and 24.6, respectively. During the first 24-h, the numbers of eggs parasitized by T. embryophagum and T. japonicum were 110.6 and 82.2, accounting for 84.7% and 59.5%, respectively, of the total parasitized eggs. After 2 months releases, the larvae and pupa density of O. arenosella under T. embryophagum and T. japonicun treatment were 0.95 and 0.94 individuals/leaflet, respectively, were significantly lower than untreated control (1.6 individuals/leaflet). These findings encouraged that T. embryophagum and T. japonicun are able to be used for biological control for O. arenosella.