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Nanomaterials ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 205
Author(s):  
María Salvador ◽  
José Luis Marqués-Fernández ◽  
José Carlos Martínez-García ◽  
Dino Fiorani ◽  
Paolo Arosio ◽  
...  

Today, public health is one of the most important challenges in society. Cancer is the leading cause of death, so early diagnosis and localized treatments that minimize side effects are a priority. Magnetic nanoparticles have shown great potential as magnetic resonance imaging contrast agents, detection tags for in vitro biosensing, and mediators of heating in magnetic hyperthermia. One of the critical characteristics of nanoparticles to adjust to the biomedical needs of each application is their polymeric coating. Fatty acid coatings are known to contribute to colloidal stability and good surface crystalline quality. While monolayer coatings make the particles hydrophobic, a fatty acid double-layer renders them hydrophilic, and therefore suitable for use in body fluids. In addition, they provide the particles with functional chemical groups that allow their bioconjugation. This work analyzes three types of self-assembled bilayer fatty acid coatings of superparamagnetic iron oxide nanoparticles: oleic, lauric, and myristic acids. We characterize the particles magnetically and structurally and study their potential for resonance imaging, magnetic hyperthermia, and labeling for biosensing in lateral flow immunoassays. We found that the myristic acid sample reported a large r2 relaxivity, superior to existing iron-based commercial agents. For magnetic hyperthermia, a significant specific absorption rate value was obtained for the oleic sample. Finally, the lauric acid sample showed promising results for nanolabeling.


Author(s):  
N Sunitha ◽  
S Manohar Babu ◽  
B Appa Rao

Lip balm was prepared and its antioxidant activity was determined by PFRAP, CUPRAC, Flourimetry methods and results of emission spectra was examined and fournd to possess almost same concentration of 0.3 ug/ml. And the ascorbic acid was determined by HPTLC method and the Rvalue of the lip balm was found to be 0.98 and is near to the abscorbic acid sample. And hence proved that beetroot lip balm was found to possess antioxidant activityThe anti oxidant activity was determined and was found to be simple, novel and economical.


2021 ◽  
Vol 908 (1) ◽  
pp. 012034
Author(s):  
E Yu Milkheev ◽  
Yu B Tsybenov

Abstract Humic substances of soils are considered as a multicomponent system of amphiphilic (exhibiting both hydrophilic and hydrophobic properties) substances. Humic substances from soils of different genesis in the south of the Vitim Plateau (quasigley chernozem – Turbic Chernozem Molliglossic and brown soil – Stagnic Phaeozem Molliglossic) were studied. Using the hydrophobic interaction chromatography on Octyl-Sepharose® CL-4B, we separated a mixture of humic (HAs) and fulvic acids (FAs) due to their different ability to enter into hydrophobic interactions with the gel matrix. A higher percentage of hydrophobic compounds was revealed in HAs of quasigley chernozem, compared to HAs of brown soils, and FAs. The fulvic acid sample showed a lower capacity for hydrophobic interactions than the humic acid sample.


2021 ◽  
Vol 2 (1) ◽  
pp. 33-48
Author(s):  
Koichiro Miyanishi ◽  
Takuya F. Segawa ◽  
Kazuyuki Takeda ◽  
Izuru Ohki ◽  
Shinobu Onoda ◽  
...  

Abstract. We demonstrate room-temperature 13C hyperpolarization by dynamic nuclear polarization (DNP) using optically polarized triplet electron spins in two polycrystalline systems: pentacene-doped [carboxyl-13C] benzoic acid and microdiamonds containing nitrogen-vacancy (NV−) centers. For both samples, the integrated solid effect (ISE) is used to polarize the 13C spin system in magnetic fields of 350–400 mT. In the benzoic acid sample, the 13C spin polarization is enhanced by up to 0.12 % through direct electron-to-13C polarization transfer without performing dynamic 1H polarization followed by 1H−13C cross-polarization. In addition, the ISE has been successfully applied to polarize naturally abundant 13C spins in a microdiamond sample to 0.01 %. To characterize the buildup of the 13C polarization, we discuss the efficiencies of direct polarization transfer between the electron and 13C spins as well as that of 13C−13C spin diffusion, examining various parameters which are beneficial or detrimental for successful bulk dynamic 13C polarization.


2021 ◽  
Vol 27 (1) ◽  
pp. 39-47
Author(s):  
Masoumeh Ghahremani ◽  
Hafezeh Salehabadi ◽  
Hamed Bahrami ◽  
Massoud Amanlou

This study aimed at examining atmospheric-pressure chemical ionization of barbituric acid through the corona discharge ion mobility spectrometry (CD-IMS) and the quantum chemical calculations. The results indicated two product ion peaks in the IMS spectrum of barbituric acid. The thermal decomposition of the barbituric acid sample was investigated by scanning the temperature of the injection port and analyzing the temporal evolution of the IMS peaks over elapsed time. It was found that the barbituric acid sample was not thermally decomposed in the injection port of the instrument. Experimental evidences were collected by changing the reactant ions, concentration of barbituric acid sample, and IMS cell temperature. The two observed peaks were then assigned to cationic form and oxygen protonated isomers of barbituric acid. The positions of the product ion peaks were explicated considering the dipole moments of the product ions.


2021 ◽  
Vol 1163 ◽  
pp. 122494
Author(s):  
Benjamin P. Sullivan ◽  
Andrew T. Bender ◽  
Duy N. Ngyuen ◽  
Jane Yuqian Zhang ◽  
Jonathan D. Posner

2020 ◽  
Author(s):  
Koichiro Miyanishi ◽  
Takuya F. Segawa ◽  
Kazuyuki Takeda ◽  
Izuru Ohki ◽  
Shinobu Onoda ◽  
...  

Abstract. We demonstrate room-temperature 13C hyperpolarization by dynamic nuclear polarization (DNP) using optically polarized triplet electron spins in two polycrystalline systems: pentacene-doped [carboxyl-13C] benzoic acid and microdiamonds containing NV- centers. For both samples, the integrated solid effect (ISE) is used to polarize the 13C spin system in magnetic fields of 350–400 mT. In the benzoic acid sample, the 13C spin polarization is enhanced up to 0.12 % through direct electron-to-13C polarization transfer without performing dynamic 1H polarization followed by 1H-13C cross polarization. In addition, ISE has been successfully applied for the first time to polarize naturally abundant 13C spins in a microdiamond sample to 0.01 %. To characterize the buildup of the 13C polarization, we discuss the efficiencies of direct polarization transfer between the electron and 13C spins as well as that of 13C–13C spin diffusion, examining various parameters which are beneficial or detrimental for successful bulk dynamic 13C polarization.


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