scholarly journals Trace Oxygen Affects Osmium Redox Polymer Synthesis for Wired Enzymatic Biosensors

2021 ◽  
Author(s):  
Margaret Calhoun ◽  
Chris Stachurski ◽  
Sara Winn ◽  
Evan Gizzie ◽  
Aaron Daniel ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Electrochemical Sensors ◽  
Type I ◽  
Type Ii ◽  
Redox Polymer ◽  
Biologically Relevant ◽  
Precursor Synthesis ◽  
New Sensors ◽  
Biological Analytes ◽  
Transport Type

Abstract Electrochemical sensors that utilize enzymes are a sensitive, inexpensive means of detecting biologically relevant analytes. These sensors are categorized based on their construction and method of signal transport. Type I sensors consist of a crosslinked enzyme on an electrode surface, and are potentially subject to interference from byproducts and other biological analytes. However, type II sensors help alleviate this problem with the addition of a redox polymer layer that assists in signal transduction, thus minimizing interferences. An osmium-loaded poly(vinylimidazole) polymer (Os-PVI) is commonly used with successful results, and when combined with an enzyme yields a type II sensor. Our initial attempts at the synthesis of this polymer resulted in an unexpected osmium precursor, which had fluorescent and redox properties that did not match with the desired Os-PVI polymer. Careful exclusion of oxygen during the Os complex precursor synthesis was necessary to avoid this unexpected oxygen containing Os-precursor, which had been seen previously in mass spectrometry studies. All precursors and osmium polymers were characterized with 1H NMR, fluorescence, mass spectrometry, and cyclic voltammetry in order to provide a better understanding of these compounds and assist in the building of new sensors.

scholarly journals Indigestão vagal em ruminantes – revisão de literatura

2020 ◽  
Vol 3 (5) ◽  
pp. 122-133
Author(s):  
Ana Clara Sarzedas Ribeiro ◽  
◽  
Ângela Imperiano da Conceição ◽  
Tatiane Vitor da Silva ◽  
Bruna Higino de Souza Silva ◽  
...  
Keyword(s):  
Correct Diagnosis ◽  
Economic Importance ◽  
Type I ◽  
Type Ii ◽  
Functional Disorder ◽  
Cattle Breeding ◽  
Type Iv ◽  
Nerve Dysfunction ◽  
Disorder Type ◽  
Transport Type

The objective was to conduct a systematic review on vagus indigestion in ruminants. This syndrome, caused by vagus nerve dysfunction and characterized by motility disorders of the pre-stomachs and abomasum, is categorized into four types, based on the location of the functional disorder: type I or failure in eructation, type II or failure in omasal transport, type III or failure in the pyloric flow and type IV or indigestion caused by advanced pregnancy. Due to its clinical and economic importance for cattle breeding, it is essential to approach this disease, aiming to expand knowledge and promote the correct diagnosis by veterinarians working in the field of internal medicine for ruminants.

scholarly journals A Fragmentation Study of Six C21 Steroidal Aglycones by Electrospray Ionization Ion-Trap Time-of-Flight Tandem Mass Spectrometry

2015 ◽  
Vol 10 (12) ◽  
pp. 1934578X1501001
Author(s):  
Xing-Long Chen ◽  
Chang-An Geng ◽  
Ji-Jun Chen
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Ion Trap ◽  
Ester Group ◽  
Type I ◽  
Tandem Mass ◽  
Type Ii ◽  
Fragmentation Pathways ◽  
Fragment Ions ◽  
Diagnostic Fragment

The fragmentation patterns of six C21 steroidal aglycones, metaplexigenin (1), caudatin (2), qingyangshengenin (3), penupogenin (4), 20-cinnamoylsarcostin (5), and gagamine (6), were analyzed by high-resolution electrospray ionization ion-trap time-of-flight tandem mass spectrometry (HR-ESI-IT-TOF-MSn). The [M-H]+ ions of steroids 1-3 that contain a carbonyl functional group at C-20 (Type I) and [M+H]+ ions of steroids 5-6 that possess a hydroxyl group at C-20 (Type II) were readily observed in MS analyses. The fragmentation pathways and diagnostic fragment ions for these six steroidal aglycones were proposed on the basis of their MSn analyses. The common fragmentation pathways for type I steroidal aglycones include the neutral loss of the ester group at C-12 and the hydroxyl moieties on the steroid skeleton, as well as the cleavage of ring D. Their diagnostic fragment ions were identified as m/ z 361(B), 343 (C), 325 (D), 307 (F), 283 (G), 259 (E), and 243 (H). The fragmentation behavior of penupogenin (4) in type II was similar to those of type I, with m/ z 363 (B’), 345 (C’), 327 (D’), 309 (F’), 283 (G), and 243 (H) as its diagnostic fragment ions. The ester group at C-20 was difficult to cleave in the MSn analyses of 20-cinnamoylsarcostin (5) and gagamine (6) so that the loss of this ester group was slower than that at C-12 and hydroxyl groups; the key ions at m/z 329 (I), 311 (J), 293 (K), and 275 (L) were characteristic for 5 and 6. The base ion peaks were derived from the loss of the substituent group at either C-12 or C-17 for both type I and type II steroidal aglycones.

scholarly journals Potential use of human hair shaft keratin peptide signatures to distinguish gender and ethnicity

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8248
Author(s):  
Nurdiena Mohamed Nasir ◽  
Jumriah Hiji ◽  
Jaime Jacqueline Jayapalan ◽  
Onn Haji Hashim
Keyword(s):  
Mass Spectrometry ◽  
Human Hair ◽  
Nuclear Dna ◽  
Hair Shaft ◽  
Type I ◽  
Type Ii ◽  
Age Range ◽  
Male Subjects ◽  
Dimensional Electrophoresis ◽  
Potential Use

Background Most human hairs collected at old crime scenes do not contain nuclear DNA and are therefore of less value for forensic investigations. In the present study, hair shaft proteins were extracted from 40 healthy subjects between the ages of 21 to 40 years and profiled using gel electrophoresis-based proteomics to determine if they can be used to distinguish gender and ethnicity. Methods Extraction of the human hair shaft proteins was performed using a newly developed alkaline solubilisation method. The extracts were profiled by 2-dimensional electrophoresis and resolved protein spots were identified by mass spectrometry and queried against the human hair database. The study was then followed-up by immunoblotting of the identified hair shaft keratin of interest using commercially available antibodies. Results Separation of the human hair shaft proteins by 2-dimensional electrophoresis generated improved and highly resolved profiles. Comparing the hair shaft protein profiles of 10 female with 10 male subjects and their identification by mass spectrometry and query of the human hair database showed significant altered abundance of truncated/processed type-II keratin peptides K81 (two spots), K83 (one spot) and K86 (three spots). The 2-dimensional electrophoresis profiling of 30 hair shaft samples taken from women of similar age range but from three distinctive ethnic subpopulations in Malaysia further showed significant altered abundance of one type-I and four type-II truncated/processed keratin peptides including K33b, K81, K83 and K86 (2 spots) between at least two of the ethnic groups. When a followed-up immunoblotting experiment was performed to detect the relative expression of the K86 peptides using commercialised antibodies, similar trends of expression were obtained. The present data, when taken together, demonstrated the potential use of keratin peptide signatures of the human hair shaft to distinguish gender and ethnicity although this needs to be further substantiated in a larger scale study.

scholarly journals Exploring Norrish type I and type II reactions: an ab initio mechanistic study highlighting singlet-state mediated chemistry

2019 ◽  
Vol 21 (26) ◽  
pp. 14418-14428 ◽  
Author(s):  
Barbara Marchetti ◽  
Tolga N. V. Karsili ◽  
Michael N. R. Ashfold
Keyword(s):  
Organic Chemistry ◽  
Ab Initio ◽  
Singlet State ◽  
Mechanistic Study ◽  
Type I ◽  
Type Ii ◽  
Biologically Relevant ◽  
Norrish Type

Norrish reactions are important photo-induced reactions in mainstream organic chemistry and are implicated in many industrially and biologically relevant processes and in the processing of carbonyl molecules in the atmosphere.

Heat-Etching with a Bullivant Type II Simple Freeze-Cleave Device

1970 ◽  
Vol 28 ◽  
pp. 106-107 ◽  
Author(s):  
Ronald S. Weinstein ◽  
N. Scott McNutt
Keyword(s):  
New Zealand ◽  
General Hospital ◽  
Massachusetts General Hospital ◽  
Type I ◽  
Type Ii ◽  
Collaborative Effort ◽  
Temperature And Pressure ◽  
The University

The Type I simple cold block device was described by Bullivant and Ames in 1966 and represented the product of the first successful effort to simplify the equipment required to do sophisticated freeze-cleave techniques. Bullivant, Weinstein and Someda described the Type II device which is a modification of the Type I device and was developed as a collaborative effort at the Massachusetts General Hospital and the University of Auckland, New Zealand. The modifications reduced specimen contamination and provided controlled specimen warming for heat-etching of fracture faces. We have now tested the Mass. General Hospital version of the Type II device (called the “Type II-MGH device”) on a wide variety of biological specimens and have established temperature and pressure curves for routine heat-etching with the device.

Labelling of non-A, non-B hepatitis infected chimpanzee hepatocytes with nuclease-gold conjugates

1984 ◽  
Vol 42 ◽  
pp. 250-251
Author(s):  
G. D. Gagne ◽  
M. F. Miller ◽  
D. A. Peterson
Keyword(s):  
Endoplasmic Reticulum ◽  
Experimental Infection ◽  
Uranyl Acetate ◽  
Type I ◽  
Cellular Injury ◽  
Type Ii ◽  
Tubular Structures ◽  
Type Iii ◽  
Type Iv ◽  
Infected Chimpanzee

Experimental infection of chimpanzees with non-A, non-B hepatitis (NANB) or with delta agent hepatitis results in the appearance of characteristic cytoplasmic alterations in the hepatocytes. These alterations include spongelike inclusions (Type I), attached convoluted membranes (Type II), tubular structures (Type III), and microtubular aggregates (Type IV) (Fig. 1). Type I, II and III structures are, by association, believed to be derived from endoplasmic reticulum and may be morphogenetically related. Type IV structures are generally observed free in the cytoplasm but sometimes in the vicinity of type III structures. It is not known whether these structures are somehow involved in the replication and/or assembly of the putative NANB virus or whether they are simply nonspecific responses to cellular injury. When treated with uranyl acetate, type I, II and III structures stain intensely as if they might contain nucleic acids. If these structures do correspond to intermediates in the replication of a virus, one might expect them to contain DNA or RNA and the present study was undertaken to explore this possibility.

Comparative surface and ultrastructural views of methylotrophic bacteria by TEM, STEM, SE, and freeze-etch electron microscopy.

1987 ◽  
Vol 45 ◽  
pp. 792-793
Author(s):  
T.A. Fassel ◽  
M.J. Schaller ◽  
M.E. Lidstrom ◽  
C.C. Remsen
Keyword(s):  
Cytoplasmic Membrane ◽  
Structural Features ◽  
Methylotrophic Bacteria ◽  
Type I ◽  
Type Ii ◽  
Membrane Complex ◽  
Oxidation Of Methane ◽  
Methane Oxidizing Bacteria ◽  
Wall Structures ◽  
Methylomonas Albus

Methylotrophic bacteria play an Important role in the environment in the oxidation of methane and methanol. Extensive intracytoplasmic membranes (ICM) have been associated with the oxidation processes in methylotrophs and chemolithotrophic bacteria. Classification on the basis of ICM arrangement distinguishes 2 types of methylotrophs. Bundles or vesicular stacks of ICM located away from the cytoplasmic membrane and extending into the cytoplasm are present in Type I methylotrophs. In Type II methylotrophs, the ICM form pairs of peripheral membranes located parallel to the cytoplasmic membrane. Complex cell wall structures of tightly packed cup-shaped subunits have been described in strains of marine and freshwater phototrophic sulfur bacteria and several strains of methane oxidizing bacteria. We examined the ultrastructure of the methylotrophs with particular view of the ICM and surface structural features, between representatives of the Type I Methylomonas albus (BG8), and Type II Methylosinus trichosporium (OB-36).

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