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91.
Magnetic nature carbon dots (MNCDs) are fast growing materials with extremely unique physico-chemical properties and physiological ability to extend their applications from separation science to detection and bio-/magnetic resonance imaging applications. Recent studies have revealed that the MNCDs are significantly used as promising agents in analytical chemistry for the separation and identification of trace level target analytes. Further, the MNCDs have been used as probes for bioimaging of cells and magnetic resonance imaging (MRI) of tumors. Due to the lack of comprehensive reviews in this emerging field especially MNCDs applications in analytical chemistry, this review may provide quick guide and reference on the MNCDs-based analytical approaches for the separation and detection of trace level analytes, and bio- and MR- imaging of various cells. In this review article, we will summarize the synthetic approaches for the fabrication of MNCDs. The main part of this proposed review is devoted to the tremendous applications of MNCDs (Fe3O4@CDs, metal ion (Fe3+, Mn2+, Co2+ and Gd2+)-doped CDs, MnO2@CDs) in analytical chemistry from separation science to detection and bio- and MR imaging. Finally, we will explore the challenges and future prospects of magneto fluorescent carbon dots in biomedical applications. 相似文献
92.
Distinguishing and quantification of the human visual pathways using high-spatial-resolution diffusion tensor tractography 总被引:1,自引:0,他引:1
Arash Kamali Khader M. Hasan Pavani Adapa Azadeh Razmandi Zafer Keser John Lincoln Larry A. Kramer 《Magnetic resonance imaging》2014
Quantification of the living human visual system using MRI methods has been challenging, but several applications demand a reliable and time-efficient data acquisition protocol. In this study, we demonstrate the utility of high-spatial-resolution diffusion tensor fiber tractography (DTT) in reconstructing and quantifying the human visual pathways. Five healthy males, age range 24–37 years, were studied after approval of the institutional review board (IRB) at The University of Texas Health Science Center at Houston. We acquired diffusion tensor imaging (DTI) data with 1-mm slice thickness on a 3.0-Tesla clinical MRI scanner and analyzed the data using DTT with the fiber assignment by continuous tractography (FACT) algorithm. By utilizing the high-spatial-resolution DTI protocol with FACT algorithm, we were able to reconstruct and quantify bilateral optic pathways including the optic chiasm, optic tract, optic radiations free of contamination from neighboring white matter tracts. 相似文献
93.
94.
Jinting Zhou Wei Lu Fangyu Hu Mengyu Zhang Liming Jiang Zhiquan Shen 《Journal of polymer science. Part A, Polymer chemistry》2014,52(16):2248-2257
A novel AB type of clickable monomer, (S)‐2‐[(2‐azido‐1‐phenylethylimino)methyl]‐5‐propargyloxyphenol (AMPP) was designed and polymerized to yield a class of main‐chain chiral poly(imine‐triazole)s through the metal‐free click reaction. With the thermally induced polymerization, the desired polytriazoles can be easily prepared in high yields by a stepwise heating‐up process and have the number‐average molecular masses ranging from 5.1 × 103 to 58.1 × 103 (polydispersity indices = 1.38?1.68). The polymers were characterized by Fourier Transform Infrared spectroscopy (FTIR), 1H Nuclear Magnetic Resonance (NMR), and gel permeation chromatography, and their optical properties were studied by fluorescence and circular dichroism (CD) spectroscopies. As a chemosensor, these polymers exhibited a selective “turn‐on” fluorescence enhancement response toward Zn2+ ion over other cations such as Na+, K+, Mg2+, Ca2+, Ag+, Pb2+, Cd2+, Hg2+, Mn2+, and Ni2+ in dimethyl sulfoxide. However, the Zn2+‐induced fluorescence signal was subject to serious interference by Al3+, Cu2+, Cr3+, and Fe3+ ions. Interestingly, the chiral polymer showed distinctive changes in the CD spectra on complexation with Zn2+, which allowed for the discrimination of this ion in the presence of other species tested including those interfering ions observed in the fluorescent detection. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2248–2257 相似文献
95.
Dr. Malin Li Dr. Yu Gao Dr. Nan Chen Dr. Xing Meng Prof. Chunzhong Wang Dr. Yaoqing Zhang Dr. Dong Zhang Prof. Yingjin Wei Dr. Fei Du Prof. Gang Chen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(32):11405-11412
Cu3V2O8 nanoparticles with particle sizes of 40–50 nm have been prepared by the co‐precipitation method. The Cu3V2O8 electrode delivers a discharge capacity of 462 mA h g?1 for the first 10 cycles and then the specific capacity, surprisingly, increases to 773 mA h g?1 after 50 cycles, possibly as a result of extra lithium interfacial storage through the reversible formation/decomposition of a solid electrolyte interface (SEI) film. In addition, the electrode shows good rate capability with discharge capacities of 218 mA h g?1 under current densities of 1000 mA g?1. Moreover, the lithium storage mechanism for Cu3V2O8 nanoparticles is explained on the basis of ex situ X‐ray diffraction data and high‐resolution transmission electron microscopy analyses at different charge/discharge depths. It was evidenced that Cu3V2O8 decomposes into copper metal and Li3VO4 on being initially discharged to 0.01 V, and the Li3VO4 is then likely to act as the host for lithium ions in subsequent cycles by means of the intercalation mechanism. Such an “in situ” compositing phenomenon during the electrochemical processes is novel and provides a very useful insight into the design of new anode materials for application in lithium‐ion batteries. 相似文献
96.
Prediction of 195Pt NMR chemical shifts of dissolution products of H2[Pt(OH)6] in nitric acid solutions by DFT methods: how important are the counter‐ion effects? 下载免费PDF全文
Athanassios C. Tsipis Ioannis N. Karapetsas 《Magnetic resonance in chemistry : MRC》2016,54(8):656-664
195Pt NMR chemical shifts of octahedral Pt(IV) complexes with general formula [Pt(NO3)n(OH)6 ? n]2?, [Pt(NO3)n(OH2)6 ? n]4 ? n (n = 1–6), and [Pt(NO3)6 ? n ? m(OH)m(OH2)n]?2 + n ? m formed by dissolution of platinic acid, H2[Pt(OH)6], in aqueous nitric acid solutions are calculated employing density functional theory methods. Particularly, the gauge‐including atomic orbitals (GIAO)‐PBE0/segmented all‐electron relativistically contracted–zeroth‐order regular approximation (SARC–ZORA)(Pt) ∪ 6–31G(d,p)(E)/Polarizable Continuum Model computational protocol performs the best. Excellent second‐order polynomial plots of δcalcd(195Pt) versus δexptl(195Pt) chemical shifts and δcalcd(195Pt) versus the natural atomic charge QPt are obtained. Despite of neglecting relativistic and spin orbit effects the good agreement of the calculated δ 195Pt chemical shifts with experimental values is probably because of the fact that the contribution of relativistic and spin orbit effects to computed σiso 195Pt magnetic shielding of Pt(IV) coordination compounds is effectively cancelled in the computed δ 195Pt chemical shifts, because the relativistic corrections are expected to be similar in the complexes and the proper reference standard used. To probe the counter‐ion effects on the 195Pt NMR chemical shifts of the anionic [Pt(NO3)n(OH)6 ? n]2? and cationic [Pt(NO3)n(OH2)6 ? n]4 ? n (n = 0–3) complexes we calculated the 195Pt NMR chemical shifts of the neutral (PyH)2[Pt(NO3)n(OH)6 ? n] (n = 1–6; PyH = pyridinium cation, C5H5NH+) and [Pt(NO3)n(H2O)6 ? n](NO3)4 ? n (n = 0–3) complexes. Counter‐anion effects are very important for the accurate prediction of the 195Pt NMR chemical shifts of the cationic [Pt(NO3)n(OH2)6 ? n]4 ? n complexes, while counter‐cation effects are less important for the anionic [Pt(NO3)n(OH)6 ? n]2? complexes. The simple computational protocol is easily implemented even by synthetic chemists in platinum coordination chemistry that dispose limited software availability, or locally existing routines and knowhow. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
97.
98.
We demonstrated a 3D laser imaging system at 1550 nm with a 1.5-GHz sine-wave gated Geiger-mode InGaAs/InP avalanche photodiode (APD). An optical fiber bundle with 100 individual fiber outputs was implemented at the focal plane of the telescope, providing a 2.5-mrad imaging view. The system used single-pixel near-infrared single-photon detector to measure photons at fiber outputs instead of a photon counting array. The 1.5-GHz gated Geiger-mode InGaAs/InP APD with a timing jitter of 290 ps was operated in quasi-continuous mode with detection efficiency of ∼4.3%. We achieved higher than 6-cm surface-to-surface resolution at single-photon level, showing a potential of low-energy and eye-safe laser imaging system for long-distance measurements. 相似文献
99.
Using a molecular dynamics simulation technique,we compared several commonly used ion-water models to describe the microscopic structures and dynamics in KSCN aqueous solutions.Results are compared with observations of femtosecond infrared vibrational-energy transfer and anisotropy measurements.The Jorgensen/TIP4P model is found to provide the best reproduction of clustering properties such as percentage of clustered ions,cluster-size distribution,concentration dependence of the water,and ion-rotation time constants. 相似文献
100.
A series of Mn(II) aminophosphonate complexes were successfully synthesized and intercalated into the hydroxy double salt [Zn5(OH)8]Cl2·yH2O. Complex incorporation led to an increase in the interlayer spacing from 7.8 to 10–12 Å. Infrared spectroscopy showed the presence of the characteristic vibration peaks of the Mn(II) complexes in the intercalates' spectra, indicating successful incorporation. The complex-loaded composites had somewhat lower proton relaxivities than the pure complexes. Nevertheless, these intercalates may have use as MRI contrast agents for patients with poor kidney function, where traditional Gd(III)-based contrast agents cause severe renal failure. 相似文献