scholarly journals Trials for Gathering Information on an Unknown Peak in the GC-MS Spectra of Horse and Pony Hair Extracts

2021 ◽  
Vol 09 (02) ◽  
pp. 100-111
Author(s):  
Maia Tsikolia ◽  
Till Opatz ◽  
Ulrich Kauhl ◽  
Nurhayat Tabanca ◽  
Betul Demirci ◽  
...  
Keyword(s):  
Unknown Peak

Analytical Evaluation of BioRad D-100 HPLC Analyzer and Workflow Comparison to BioRad TurboLink Variant II HPLC With Reflex to Boronate Affinity

2019 ◽  
Vol 152 (Supplement_1) ◽  
pp. S12-S13
Author(s):  
Kornelia Galior ◽  
Lisha Leonard ◽  
Christopher Dolan ◽  
Ryan Deiter ◽  
Nikola A Baumann ◽  
...  
Keyword(s):  
Cation Exchange ◽  
High Performance ◽  
Exchange Chromatography ◽  
Rule Violation ◽  
Before And After ◽  
Patients With Diabetes ◽  
Unknown Peak ◽  
Reflex Testing ◽  
Boronate Affinity Chromatography ◽  
Hemoglobin Variants

Abstract Introduction Measurement of hemoglobin A1c (HbA1C) is used for the diagnosis and management of patients with diabetes. Methods for measuring HbA1C are classified on the basis of charge differences (cation exchange chromatography) or structural differences (boronate affinity chromatography). Some cation exchange high-performance liquid chromatography (HPLC) analyzers may be prone to interferences from hemoglobin variants. Historically, our lab used two methods to report HbA1C results: cation exchange HPLC (VariantII) with reflex to boronate affinity HPLC (Ultra2) methods. A new analyzer (BioRad D-100) with improved interference detection and thresholds for interference was evaluated. The objectives of this study were (1) assess the comparability of HbA1c results between D-100, VariantII, and Ultra2; (2) evaluate the need for maintaining a reflex method; and (3) calculate cancellation rates before and after implementing D-100. Methods HbA1c was measured by cation exchange methods using VariantII Turbolink, D-100 (BioRad), and boronate affinity using Ultra2Affinity (Trinity Biotech) according to the manufacturer’s recommendations with the following analytical measuring ranges (AMRs), 4.0% to 17.6%, 4.0% to 18.0%, and 4.0% to 17.6%, respectively. D-100 was compared to VariantII (n = 26) and Ultra2 (n = 31) using residual patient samples from provider-ordered HbA1c having no chromatography flags and with the following chromatography flags on VariantII (n = 113): variant window (n = 41), HbA1c <4.0% (n = 24), HbA1a + HbA1b >5% (n = 19), HbF >5% (n = 9), P3 >10% (n = 6), HbA1c >17.6% (n = 4), unknown peak (n = 3), labile 5% to 15% (n = 3), labile >15% (n = 3), and HbS >60% (n = 1). The cancelation rates were calculated at baseline (January 1-31, 2018) and postimplementation of D-100 (September 20, 2018, to January 22, 2019). Results HbA1c results from D-100 were within ±0.3 or 5% with the following frequencies: Ultra2 in 96.2% (25/26) with VariantII in 96.8% (30/31) using samples with no chromatography flags. A total of 113 samples with abnormal VariantII flags were tested using D-100 with 82% (n = 92) not exceeding interference limits for result reporting. These D-100 results were within ±0.3 or 5% of Ultra2 results with the following frequencies: 38.5% (10/26) of samples below (n = 23) or above (n = 3) the AMR, 85.3% (29/34) of results with Hb variant flags, 68.0% (17/25) with unknown/minor peaks, and 71.4% (5/7) with HbF <15%. The clinical concordance was also assessed according to the following decision limits: normal <5.6%, prediabetic = 5.7% to 6.4%, and diabetic >6.5%. Results were concordant in 88% with variant peaks (12/13 w/HbA1c <5.6%, 8/11 w/HbA1c = 5.7%-6.4%, 10/10 w/HbA1c >6.5%), 84% with minor peaks (5/6 w/HbA1c <5.6%, 0/2 w/HbA1c = 5.7%-6.4%, 16/17 w/HbA1c >6.5%), and 86% with HbF (3/3 w/HbA1c <5.6%, 2/3 w/HbA1c = 5.7%-6.4%, 1/1 w/HbA1c >6.5%). Results above/below AMR had 100% concordance (>16.0% or <4.4%). The frequency of VariantII rule violation was 2.1% in January 2018, with 53 of 117 having results confirmed as <4.0% or >16.0% by Ultra2, 2 of 117 reported by Ultra2, and 62 being cancelled due to HbF >15% (n = 23) or variant Hb >60% (n = 39). The frequency of rule violation using only D-100 since implementation was 2.2%. Conclusion Implementation of D-100 has removed the need for boronate affinity reflex testing and maintained similar cancellation rates.

scholarly journals A case of iron deficiency anemia with co-existing Hb Fontainebleau.

2014 ◽  
Vol 6 (1) ◽  
pp. e2014051 ◽  
Author(s):  
Abhishek HL Purohit ◽  
Mukul Aggarwal ◽  
Roshan B Colah ◽  
Anita H Nadkarni ◽  
Hara P Pati
Keyword(s):  
Iron Deficiency ◽  
Molecular Characterization ◽  
Iron Deficiency Anemia ◽  
Indian Population ◽  
Family Study ◽  
Deficiency Anemia ◽  
Diagnostic Difficulty ◽  
Unknown Peak ◽  
Hplc Study ◽  
Chain Variant

Hb Fontainebleaue is a rare alpha chain variant in the Indian population which generates an unknown peak on hemoglobin HPLC study and does cause diagnostic difficulty to those who are not acquainted with this entity. We present a case of Hb Fontainebleau, an eighteen year old patient who presented with symptoms related to anemia to our department and unknown peak observed in HPLC plots lead us to family study and molecular characterization for this case.

Deformation in Mono-Crystalline Silicon Caused by High Speed Single-Point Micro-Cutting

2009 ◽  
Vol 407-408 ◽  
pp. 347-350
Author(s):  
A.Q. Biddut ◽  
Ji Wang Yan ◽  
Liang Chi Zhang ◽  
Tsutomu Ohta ◽  
Tsunemoto Kuriyagawa ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Feed Rate ◽  
High Speed ◽  
Crystalline Silicon ◽  
Single Point ◽  
Cutting Speed ◽  
Amorphous Layer ◽  
Depth Of Cut ◽  
Transmission Electron ◽  
Unknown Peak

This paper investigates the deformation in monocrystalline silicon subjected to single-point cutting with the cutting speed up to 46.78 m/s, the depth of cut of 2 μm, and the feed rate of 5 and 30 μm/rev. Raman spectroscopy and transmission electron microscopy were used to characterize the subsurface damages. It was found that the increase of either the feed rate or cutting speed increases the thickness of amorphous layer and penetration depth of dislocations. At the feed rate of 30 μm/rev and cutting speed of 12.48 m/s, a new dislocation system was initiated. An unknown peak was detected by Raman spectroscopy, which may indicate an unknown Si phase.

scholarly journals HBQ-India: an uncommon hemoglobin variant

2018 ◽  
Vol 6 (5) ◽  
pp. 1687
Author(s):  
Manjusha Dhawle ◽  
Ashok Methwani ◽  
Ashwini Tangde ◽  
Rajan Bindu
Keyword(s):  
Beta Thalassaemia ◽  
Arms Pcr ◽  
Sindh Province ◽  
High Prevalence ◽  
Different Types ◽  
Mutation System ◽  
Unknown Peak ◽  
Alpha Thalassaemia ◽  
Polymerase Chain ◽  
Hbq India

Background: HbQ-India is a rare alpha chain variant. It is an important member of the hemoglobin Q family molecularly characterized by replacement of aspartic acid by histidine. It usually presents in the heterozygous state. It becomes symptomatic only in the homozygous state and when present in association with other conditions like beta-thalassaemia, alpha thalassaemia, HbE and HbH. The Sindhi is one of the largest linguistic communities, migrated about 65 years back from the Sindh province of west Pakistan to India. They are a high-risk community for beta thalassaemia gene in India with a carrier frequency ranging from 5 to 12 % with a distinct regional variability.Methods: A total 343 cases were screened for hemoglobinopathies in Sindhi population. Detail history was taken from each patient and pertinent physical finding were noted. CBC, Peripheral smear and HPLC were performed. During screening we observed that few samples showed an unknown peak at a retention time of 4.7 min on HPLC and comparison with reference chromatograms indicated them to be HbQ India and it is confirmed by amplification restriction mutation system polymerase chain reaction (ARMS-PCR).Results: We found 13 cases, 12 cases of HbQ India and 1 case of HbQ-beta thalassaemia in Sindhi population of Aurangabad in Maharashtra.Conclusions: India is known as a country with a high prevalence of different types of hemoglobinopathy. Now a days HPLC, IEF, ARMS-PCR, DNA sequencing are the methods available for the diagnosis of the abnormal Hb like HbQ-lndia. HPLC is a cheaper alternative to ARMS-PCR in the detection of rare hemoglobinopathies.

scholarly journals Nonparametric Tests for the Umbrella Alternative with Unknown Peak in a Mixed Design

2020 ◽  
pp. 1-13
Author(s):  
Hassan Alsuhabi ◽  
Rhonda Magel
Keyword(s):  
Simulation Study ◽  
Nonparametric Tests ◽  
Asymptotic Distributions ◽  
Test Statistics ◽  
Mixed Design ◽  
Randomized Design ◽  
Umbrella Alternative ◽  
Unknown Peak ◽  
Completely Randomized Design ◽  
Better Than

Aims: Introducing and comparing 4 different tests for the unknown umbrella alternative in a mixed design. Study Design: Simulation study consisting of a randomized complete block portion and a completely randomized design portion for various underlying distributions. Place and Duration of Study: Simulation Study – conducted at North Dakota State University from September 2018 through December 2019. Methodology: This paper proposes four non-parametric tests for testing the umbrella alternative with unknown peak when the data are mixture of a randomized complete block and a completely randomized design. The proposed tests are various combinations of a modified (unmodified) Mack-Wolfe’s test and a modified (unmodified) Kim-Kim’s test, respectively. In this paper, the proposed tests are an extension of Magel et al. (2010) and Hassan and Magel (2020) peak known tests to the unknown peak setting. The four proposed test statistics are compared to each other. Results: When there were 3 populations, the unmodified versions of the test statistics did better than the modified versions.  When there were 4 and 5 populations, the results varied. Conclusion: All of the test statistics reached their asymptotic distributions quickly.  The standardize first versions of the test statistics were generally better than the standardized last version of the test statistics, which meant that it was better to place equal weights on the RCBD portion and the CRD portion.

scholarly journals Isolation and Identification of Non-Conjugated Linoleic Acid from Processed Panax ginseng Using LC-MS/MS and 1H-NMR

Separations ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 208
Author(s):  
Tae-Kyung Kim ◽  
Changsuk Lee ◽  
Taek-Hee Nam ◽  
Yong-Ki Seo ◽  
Kyeong-Soo Kim ◽  
...  
Keyword(s):  
Linoleic Acid ◽  
Linoleic Acid Content ◽  
Conjugated Linoleic Acids ◽  
Isolation And Identification ◽  
Pharmacological Activities ◽  
Chemical Structures ◽  
Liquid Chromatography Tandem Mass ◽  
Unknown Peak ◽  
Black Ginseng ◽  
White Ginseng

Black ginseng exhibits numerous pharmacological activities due to higher and more diverse ginsenosides than unprocessed white ginseng. The ginsenoside derivatives have been investigated in order to determine their chemical structures and pharmacological activities. We found a peak which was increased 10-fold but unidentified in the methanol extracts of a black ginseng product. The unknown peak was tracked and identified as linoleic acid rather than a ginsenoside derivative using liquid chromatography–tandem mass spectrometry (LC-MS/MS) and nuclear magnetic resonance (NMR) spectroscopy. NMR analysis confirmed no presence of conjugated linoleic acids. Ginsenoside profiles and linoleic acid contents in black ginseng products were quantified using LC-MS/MS. Linoleic acid content was more directly proportional to the number of applied thermal cycles in the manufacturing process than any ginsenosides.

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