Notes
![]() ![]() Notes - notes.io |
1 ng g-1 level, depending on the matrix. Additional validation was performed by tandem mass spectrometry on a triple quadrupole instrument. This approach provided no non-detects and better recoveries at the 0.1 ng g-1 level than the HRMS method but exhibited more variability at 1 and 5 ng g-1 spiking levels. Analysis of NIST SRMs 1946 and 1947 gave accuracies of 70-117%. These results demonstrate the capability of combining PFAS analysis with a mega-method previously validated for 350 analytes, while collecting non-target data for future retrospective analysis of emerging alternatives with a high-resolution mass spectrometry method.Long-acting parenteral (LAP) implant has garnered the attraction as a drug delivery technique in recent years. Understanding the drug release process is critical for the study of underlying release mechanism. In this paper, we present a novel application of matrix-assisted laser desorption/ionization-mass spectrometry imaging (MADLI-MSI) for the direct visualization of the drug release process from non-conductive polymeric based LAP implants at molecular level. Custom-made sample holders were designed for LAP sample introduction in place of traditional conductive glass slides. The main technical obstacles of applying MALDI-MSI to study non-conductive materials are surface conductivity which can lead to charge build-up. In order to obtain homogeneous imaging of non-conductive sample surfaces, we developed a new sample surface treatment procedure, which is a critical control step to ensure the data reliability and accuracy in understanding kinetics of drug release process of LAP. Overall, this is the first comprehensive report of a sample preparation methodology tailored for imaging LAP at molecular level, allowing for the direct chemical identification and 2D mapping of an active pharmaceutical ingredient (API) distribution during LAP release process. Furthermore, this work has established the foundation to apply MALDI-MSI to the understanding of LAP implant formulation homogeneity, chemical composition, and degradation. More importantly, this work enabled the extension of MALDI-MSI technique to study a wide range of non-conductive materials.β-coronaviruses (β-CoVs), representative with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), depend on their highly glycosylated spike proteins to mediate cell entry and membrane fusion. Compared with the extensively identified N-glycosylation, less is known about O-glycosylation of β-CoVs S proteins, let alone its biological functions. Herein we comprehensively characterized O-glycosylation of five recombinant β-CoVs S1 subunits and revealed the macro- and micro-heterogeneity nature of site-specific O-glycosylation. We also uncovered the O-glycosylation differences between SARS-CoV-2 and its natural D614G mutant on functional domains. This work describes the systematic O-glycosylation analysis of β-CoVs S1 proteins and will help to guide the related vaccines and antiviral drugs development.The concentration variation of phenylalanine (Phe), an essential amino acid in humans, can cause metabolism disorders and even mental disability. Sensitive and convenient monitoring of Phe is therefore important for disease diagnosis. We describe here the establishment of a new aptamer-based, sensitive and label-free colorimetric Phe detection strategy by integrating catalytic hairpin assembly (CHA) and Mg2+-dependent DNAzyme amplification cascades. The target Phe coordinates with pentamethylcyclopentadienyl rhodium(III) chloride dimer [(Cp*RhCl2)2] to form a complex that has a high affinity to the corresponding aptamer sequence. Upon its binding to the aptamers in DNA duplex probes, ssDNA strands are released to trigger subsequent CHA reactions for the formation of many DNAzymes, which cleave the substrate signal probes to liberate lots of CHA initiation strands and free G-quadruplexes to realize the cascaded amplifications. Hemin further associates with the many G-quadruplexes to yield hemin/G-quadruplex mimicking peroxidases, which catalyze solution of substrate to exhibit highly enhanced UV-vis adsorption for detecting Phe at 0.19 μM level. At the meantime, the monitoring of Phe in diluted serums with high selectivity has also been demonstrated by the developed method, indicating its potential for simple diagnosis of Phe-related diseases.Protein sialylation participates many biological processes in a linkage-specific manner, and aberrant sialylation has been associated with many malignant diseases. Mass spectrometry-based quantitative N-glycoproteomics has been widely adopted for quantitative analysis of aberrant sialylation, yet multiplexing method at intact N-glycopeptides level is still lacking. Here we report our study of sialic acid linkage-specific quantitative N-glycoproteomics using selective alkylamidation and multiplex tandem mass tags (TMT)-labeling. With lung cancer as a model system, differential sialylation in cancer tissues relative to adjacent non-tumor tissues was characterized at the intact N-glycopeptide level with N-glycosite information. TMT-labeled intact N-glycopeptides with and without sialic acid alkylamidation were subject to reversed-phase liquid chromatography-nano-electron spray ionization-tandem mass spectrometry (RPLC-nanoESI-MS/MS) analysis to provide comprehensive characterization of N-glycosylation with and without sialic acid at the intact N-glycopeptide level with structure and N-glycosite. In this study, 6384 intact N-glycopeptides without sialylation were identified and 521 differentially expressed intact N-glycopeptides from 254 intact N-glycoproteins were quantified. Eight intact N-glycoproteins responsible for N-glycan biosynthesis were identified as glycosyltransferases. In total, 307 sialylated intact N-glycopeptides with linkage-specific sialic acid residues were identified together with 29 N-glycans with α2,6-linked sialic acids and 55 N-glycans with α2,3-linked sialic acids. Intact N-glycoproteins with α2,6-sialylation were associated with coronavirus disease-(COVID)-19. Additionally, many types of N-glycosylation including terminal N-galactosylation, core and/or branch fucosylation, α2,6-sialylation and terminal bisecting N-acetylglucosamine were identified and quantified in intact N-glycoproteins from immunoglobulin family.SARS-CoV-2 viruses, responsible for the COVID-19 pandemic, continues to evolve into new mutations, which poses a significant threat to public health. Current testing methods have some limitations, such as long turnaround times, high costs, and professional laboratory requirements. In this report, the novel Spin-Enhanced Lateral Flow Immunoassay (SELFIA) platform and fluorescent nanodiamond (FND) reporter were utilized for the rapid detection of SARS-CoV-2 nucleocapsid and spike antigens from different variants, including wild-type (Wuhan-1), Alpha (B.1.1.7), Delta (B.1.617.2), and Omicron (B.1.1.529). The SARS-CoV-2 antibodies were conjugated with FND via nonspecific binding, enabling the detection of SARS-CoV-2 antigens via both direct and competitive SELFIA format. Direct SELFIA was performed by directly adding the SARS-CoV-2 antibodies-conjugated FND on the antigens-immobilized nitrocellulose (NC) membrane. Conversely, the SARS-CoV-2 antigen-containing sample was first incubated with the antibodies-conjugated FND, and then dropped on the antigen-immobilized NC membrane to carry out the competitive SELFIA. The results suggested that S44F anti-S IgG antibody can be efficiently used for the detection of wild-type, Alpha, Delta, and Omicron variants spike antigens. Findings were comparable in direct SELFIA, competitive SELFIA, and ELISA. A detection limit of 1.94, 0.77, 1.14, 1.91, and 1.68 ng/mL can be achieved for SARS-CoV-2 N protein, wild-type, Alpha, Delta, and Omicron S proteins, respectively, via competitive SELFIA assay. These results suggest that a direct SELFIA assay can be used for antibody/antigen pair screening in diagnosis development, while the competitive SELFIA assay can serve as an accurate quantitative diagnostic tool. The simplicity and rapidity of the SELFIA platform were demonstrated, which can be leveraged in the detection of other infectious diseases in the near future.All electrolytic vapor generation technologies are based on cathodic reduction, but this paper focuses on how to use anodic oxidation to realize the gaseous transformation of noble metal Os. Supported by RuO2-based dimensionally stable anode (DSA), we found that the conversion from trivalent/tetravalent Os to the OsO4 can be carried out continuously and stably, even at the μg L-1 level. Interestingly, there was a negative correlation between the conversion of OsO4 and the RuO2 content in the DSA. The decrease of oxygen absorption potential and the increase of current density suggest that the oxidation process of Os belongs to electrocatalytic behavior. The catalytic activity of the material has an obvious influence on the conversion of osmium while the formation of free radical may be crucial for the effective oxidation. Under the optimum conditions, this electrocatalytic synthesis of OsO4 combined with ICP-MS can realize the same effect of oxidation and detection of two osmium species [Os(III) and Os(IV)]. The proposed method exhibits a low limit of detection (5 pg kg-1), a wide linear range (0.1-100 μg L-1) and excellent anti-interference performance, which promotes the direct analysis of total Os in real ore samples without separation. Considering the catalytic activity of OsO4 in specific reactions, this green anodic electrosynthesis technology is also expected to provide more possibilities.Herein we report a novel colorimetric sensing strategy for the detection of kanamycin (kana) based on target-induced gold nanoparticles (AuNPs) coupled with aptamers. Aptamer-functionalized AuNPs, as the colorimetric probe, showed a distinct red shift with addition of kana, which avoiding the tedious and unnecessary additive-induced process. To study the interaction between kana and AuNPs and the effects of the specific aptamer adsorption, a series of experiments including UV-vis absorbance and surface enhanced Raman spectroscopy (SERS) were performed. Based on the results, a new alternative view is proposed that kana can directly induce the aggregation of aptamer-wrapped AuNPs, attributed to the co-adsorption of kana and aptamer on the surface of AuNPs. The proposed colorimetric sensing exhibited high selectivity and sensitivity for kanamycin assay with a wide linear range from 10.0 nM to 4.0 μM, and the limit of detection (LOD) reached 4.0 nM. Moreover, the whole detection process could be completed within 5 min, and it also achieved excellent performance in real samples detection with recoveries in the range of 86.22-109.89%. The results indicate that target-induced AuNPs colorimetric sensing coupled with aptamers for the direct detection of kana is simple, rapid and high-sensitivity, has the promising potential applications in the fields of food safety and environmental monitoring.Detection of hydrogen peroxide and glucose in nanomolar level is crucial for point-of-care medical diagnosis. It has been reported that human's central nervous system diseases such as Alzheimer's disease, Parkinson's disease, and even amyotrophic lateral sclerosis, are presumably caused H2O2 or reactive radical species (ROS). Proteasome inhibitor Sensing of H2O2 released from human biofluids, tissues, organ from metabolism disorder at ultra-low concentration assists for early identification of severe diabetis mellitus related to glucose, and heart attack, as well as stroke related to cholesterol. In this work, carbon dots (CDs) having an average diameter at 6.99 nm with highly photoluminescence performance were successfully synthesized from palm empty fruit bunch (EFB) using green and environmentally friendly process via hydrothermal condition. CDs acted well on peroxidase-like activity for H2O2 detection at room temperature, however their sensitivity on ultra-low H2O2 concentration needed to be improved. To enhance their reactivity on H2O2 nanozyme activity at room temperature, synthesis of hybrid metal nanoparticles (AgNPs and PtNPs) on CDs surface was established.
Homepage: https://www.selleckchem.com/Proteasome.html
![]() |
Notes is a web-based application for online taking notes. You can take your notes and share with others people. If you like taking long notes, notes.io is designed for you. To date, over 8,000,000,000+ notes created and continuing...
With notes.io;
- * You can take a note from anywhere and any device with internet connection.
- * You can share the notes in social platforms (YouTube, Facebook, Twitter, instagram etc.).
- * You can quickly share your contents without website, blog and e-mail.
- * You don't need to create any Account to share a note. As you wish you can use quick, easy and best shortened notes with sms, websites, e-mail, or messaging services (WhatsApp, iMessage, Telegram, Signal).
- * Notes.io has fabulous infrastructure design for a short link and allows you to share the note as an easy and understandable link.
Fast: Notes.io is built for speed and performance. You can take a notes quickly and browse your archive.
Easy: Notes.io doesn’t require installation. Just write and share note!
Short: Notes.io’s url just 8 character. You’ll get shorten link of your note when you want to share. (Ex: notes.io/q )
Free: Notes.io works for 14 years and has been free since the day it was started.
You immediately create your first note and start sharing with the ones you wish. If you want to contact us, you can use the following communication channels;
Email: [email protected]
Twitter: http://twitter.com/notesio
Instagram: http://instagram.com/notes.io
Facebook: http://facebook.com/notesio
Regards;
Notes.io Team