(63)Nickel radioactive ionization ((63)Ni) is the most common and widely used ion source for ion mobility spectrometry (IMS). Regulatory, financial, and operational concerns with this source have promoted recent development of non-radioactive sources, such as corona discharge ionization (CD), for stand-alone IMS systems. However, there has been no comparison of the negative ion species produced by all three sources in the literature. This study compares the negative reactant and analyte ions produced by three sources on an ion mobility-mass spectrometer: conventional (63)Ni, CD, and secondary electrospray ionization (SESI). Results showed that (63)Ni and SESI produced the same reactant ion species while CD produced only the nitrate monomer and dimer ions. The analyte ions produced by each ion source were the same except for the CD source which produced a different ion species for the explosive RDX than either the (63)Ni or SESI source. Accurate and reproducible reduced mobility (K0) values, including several values reported here for the first time, were found for each explosive with each ion source. Overall, the SESI source most closely reproduced the reactant ion species and analyte ion species profiles for (63)Ni. This source may serve as a non-radioactive, robust, and flexible alternative for (63)Ni.
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http://dx.doi.org/10.1016/j.talanta.2013.01.009 | DOI Listing |
ACS Nano
January 2025
National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, P. R. China.
Regeneration of diabetic bone defects remains a formidable challenge due to the chronic hyperglycemic state, which triggers the accumulation of advanced glycation end products (AGEs) and reactive oxygen species (ROS). To address this issue, we have engineered a bimetallic metal-organic framework-derived Mn@CoO@Pt nanoenzyme loaded with alendronate and Mg ions (termed MCPtA) to regulate the hyperglycemic microenvironment and recover the osteogenesis/osteoclast homeostasis. Notably, the Mn atom substitution in the CoO nanocrystalline structure could modulate the electronic structure and significantly improve the SOD/CAT catalytic activity for ROS scavenging.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Institute of Organic Chemistry, University Regensburg, Universitätsstr. 31, 93053 Regensburg, Germany.
In ion-pair catalysis, the last intermediate structures prior to the stereoselective transition states are of special importance for predictive models due to the high isomerization barrier between - and -substrate double bonds connecting ground and transition state energies. However, in prior experimental investigations of chiral phosphoric acids (CPA) solely the early intermediates could be investigated while the key intermediate remained elusive. In this study, the first experimental structural and conformational insights into ternary complexes with CPAs are presented using a special combination of low temperature and relaxation optimized N HSQC-NOESY NMR spectroscopy to enhance sensitivity.
View Article and Find Full Text PDFBMC Med Genomics
January 2025
Department of Clinical Laboratory Sciences, The Faculty of Applied Medical Sciences, Taif University, Taif, Saudi Arabia.
Naegleria fowleri, the causative agent of Primary Amoebic Meningoencephalitis (PAM), is commonly found in warm freshwater environments and can enter the brain through nasal passages during activities like swimming or ablution. PAM has a high fatality rate, raising concerns about its global health impact. In Pakistan, particularly in Karachi, a significant number of cases have been reported, often with no history of recreational water exposure, but with regular ablution using tap water.
View Article and Find Full Text PDFBMC Plant Biol
January 2025
Plant Production Department, College of Food and Agricultural Sciences, King Saud University, P.O. Box. 2460, Riyadh, 11451, Saudi Arabia.
Water scarcity is a foremost environmental concern and is expected to hasten in the forthcoming years due to severe fluctuations in weather patterns worldwide. The present work was designed to explore the potential role of alpha-tocopherol (α-Toc), a form of vitamin E, on the morphological, physio-biochemical, and cellular antioxidant responses of two radish genotypes grown under drought conditions (38 ± 3% of field capacity). The individual and combined applications of α-Toc (100 ppm) were used as T0- Control, T1- Control + TF (TF-alpha-tocopherol), T2- Drought (D), and T3- D + TF with three replications.
View Article and Find Full Text PDFFood Res Int
January 2025
Sericultural & Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Agricultural Products Processing, Guangdong 510610, China. Electronic address:
Health benefit effects of bioactive compounds depend on their bioavailabilities, which could vary according to factors including food matrix and digestion environment. To understand the "bioaccessible" health benefit of red pitay pulp, the INFOGEST static in vitro simulation of gastrointestinal (GI) digestion model and targeted metabolomics method were applied to unravel the fates of bioactive compounds in the whole food of red pitaya pulp during GI digestion. The antioxidant activity as one of the health benefit indices was also assessed to compare the changes in bioactive properties of red pitaya pulp.
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