Evaluation and improvement of the oxidative stability of leather fatliquors

AbstractFatliquor oxidation may give leather unpleasant odor, and excessive amounts of Cr(VI) and volatile organic compounds. The accurate evaluation and improvement of the oxidative stability of fatliquors are of great significance to high-quality leather manufacturing. We proposed a set of practical methods for evaluating the oxidative stability of fatliquors on the basis of oxidation induction time, change in iodine value (∆ IV), and change in acid value (∆ AV) under accelerated oxidation conditions (at 100 °C with 10 L/h of air). Oxidation induction time is a highly sensitive marker for quantifying the oxidative stability of fatliquors, and ∆ IV and ∆ AV that are low cost and easy to operate are useful in evaluating the oxidative stability of fatliquors when the oxidation induction time is less than 22 h. The number of double bonds in fatliquors is an important factor affecting oxidative stability. The sulfation modification of fatliquors that greatly reduces double bonds and the addition of antioxidants, especially butylated hydroxyanisole and butylated hydroxytoluene, markedly improve oxidative stability of fatliquors.

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On the Oxidation Induction Time and Oxidation Induction Temperature for Characterization of the Oxidative Stability of Poly(ethylene-co-propylene) Pipes

10.7546/grabs2018.1.05 ◽

2018 ◽

Author(s):

Anton A. Apostolov

Keyword(s):

Oxidative Stability ◽

Induction Time ◽

Oxidation Induction Time ◽

Oxidation Induction Temperature ◽

Poly Ethylene ◽

Induction Temperature

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On the Oxidation Induction Time and Oxidation Induction Temperature for Characterization of the Oxidative Stability of Poly(ethylene-co-propylene) Pipes

10.7546/crabs.2018.01.05 ◽

2018 ◽

Author(s):

Anton A. Apostolov

Keyword(s):

Oxidative Stability ◽

Induction Time ◽

Oxidation Induction Time ◽

Oxidation Induction Temperature ◽

Poly Ethylene ◽

Induction Temperature

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A rapid, accurate, scalable, and portable testing system for COVID-19 diagnosis

Nature Communications ◽

10.1038/s41467-021-23185-x ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Guanhua Xun ◽

Stephan Thomas Lane ◽

Vassily Andrew Petrov ◽

Brandon Elliott Pepa ◽

Huimin Zhao

Keyword(s):

Limit Of Detection ◽

Low Cost ◽

High Volume ◽

N Gene ◽

Testing System ◽

Target Sequence ◽

One Pot ◽

Sequence Detection ◽

Highly Sensitive ◽

Speed Accuracy

AbstractThe need for rapid, accurate, and scalable testing systems for COVID-19 diagnosis is clear and urgent. Here, we report a rapid Scalable and Portable Testing (SPOT) system consisting of a rapid, highly sensitive, and accurate assay and a battery-powered portable device for COVID-19 diagnosis. The SPOT assay comprises a one-pot reverse transcriptase-loop-mediated isothermal amplification (RT-LAMP) followed by PfAgo-based target sequence detection. It is capable of detecting the N gene and E gene in a multiplexed reaction with the limit of detection (LoD) of 0.44 copies/μL and 1.09 copies/μL, respectively, in SARS-CoV-2 virus-spiked saliva samples within 30 min. Moreover, the SPOT system is used to analyze 104 clinical saliva samples and identified 28/30 (93.3% sensitivity) SARS-CoV-2 positive samples (100% sensitivity if LoD is considered) and 73/74 (98.6% specificity) SARS-CoV-2 negative samples. This combination of speed, accuracy, sensitivity, and portability will enable high-volume, low-cost access to areas in need of urgent COVID-19 testing capabilities.

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Immobilization of Pseudomonas aeruginosa static biomass on eggshell powder for on-line preconcentration and determination of Cr (VI)

Open Chemistry ◽

10.1515/chem-2020-0031 ◽

2020 ◽

Vol 18 (1) ◽

pp. 303-313 ◽

Cited By ~ 1

Author(s):

Aamir Rasheed ◽

Tahseen Ghous ◽

Sumaira Mumtaz ◽

Muhammad Nadeem Zafar ◽

Kalsoom Akhter ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Low Cost ◽

Colorimetric Detection ◽

Time Flow ◽

Highly Sensitive ◽

Glass Column ◽

On Line ◽

Preconcentration Time ◽

Ultra Trace

AbstractIn the present work, a novel continuous flow system (CFS) is developed for the preconcentration and determination of Cr (VI) using Pseudomonas aeruginosa static biomass immobilized onto an effective and low-cost solid support of powdered eggshells. A mini glass column packed with the immobilized biosorbent is incorporated in a CFS for the preconcentration and determination of Cr (VI) from aqueous solutions. The method is based on preconcentration, washing and elution steps followed by colorimetric detection with 1,5-diphenyl carbazide in sulphuric acid. The effects of several variables such as pH, retention time, flow rate, eluent concentration and loaded volume are studied. Under optimal conditions, the CFS method has a linear range between 10 and 100 μg L-1 and a detection limit of 6.25 μg L-1 for the determination of Cr (VI). The sampling frequency is 10 samples per hour with a preconcentration time of 5 mins. Furthermore, after washing with a 0.1 M buffer (pH 3.0), the activity of the biosorbent is regenerated and remained comparable for more than 200 cycles. Scanning electron microscopy reveals a successful immobilization of biomass on eggshells powder and precipitation of Cr (VI) on the bacterial cell surface. The proposed method proves highly sensitive and could be suitable for the determination of Cr (VI) at an ultra-trace level.

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A new highly sensitive and specific overnight combined screening and diagnostic test for primary aldosteronism

Acta Endocrinologica ◽

10.1530/eje-16-0003 ◽

2016 ◽

Vol 175 (1) ◽

pp. 21-28 ◽

Cited By ~ 6

Author(s):

Vaios Tsiavos ◽

Athina Markou ◽

Labrini Papanastasiou ◽

Theodora Kounadi ◽

Ioannis I Androulakis ◽

...

Keyword(s):

Diagnostic Test ◽

Sensitivity And Specificity ◽

Primary Aldosteronism ◽

Low Cost ◽

Confirmatory Test ◽

Outpatient Basis ◽

Endocrine Hypertension ◽

Serum Aldosterone ◽

Highly Sensitive ◽

Aldosterone To Renin Ratio

Context Primary aldosteronism (PA) is the most common cause of endocrine hypertension that is diagnosed following a two-step process: an initial screening test, based on the serum aldosterone-to-renin ratio (ARR), followed by a relatively laborious and time-consuming confirmatory test to document autonomous aldosterone (ALD) secretion. Objective The aim of this study is to develop a simple overnight test for the early and definite diagnosis of PA. Patients and methods Totally, 148 hypertensive patients underwent a fludrocortisone–dexamethasone suppression test (FDST) and the new overnight diagnostic test (DCVT) using pharmaceutical RAAS (renin–angiotensin–aldosterone system) blockade with dexamethasone, captopril and valsartan. Results Of the 148 patients, 45 were diagnosed as having PA and they all normalized their elevated blood pressure (BP) after administration of spironolactone or eplerenone. The remaining 103 patients were considered as having essential hypertension and served as controls. Using ROC analysis, the estimated sensitivity and specificity were 91 and 100%, respectively, for the post-FDST ARR, whereas 98% and 89% and 100% and 82% for the post-DCVT ARR and post-DCVT ALD, respectively, with selected cutoffs of 0.32ng/dL/μU/mL and 3ng/dL respectively. However, considering these cutoffs simultaneously, the estimated sensitivity and specificity were 98 and 100% respectively. Applying these cutoffs, the diagnosis of PA was confirmed in 44 (98%) of the 45 patients who were considered to have the disease. Conclusions In this study, a highly sensitive and specific, low-cost, rapid, safe, and easy-to-perform diagnostic test (DCVT) for PA is described, which could be utilized on an outpatient basis potentially substituting conventional laborious testing.

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Highly sensitive detection of Cr(vi) in groundwater by bimetallic NiFe nanoparticles

Analytical Methods ◽

10.1039/c6ay03089k ◽

2017 ◽

Vol 9 (6) ◽

pp. 1031-1037 ◽

Cited By ~ 3

Author(s):

Jingtao Liu ◽

Yu Ding ◽

Lifei Ji ◽

Xin Zhang ◽

Fengchun Yang ◽

...

Keyword(s):

Heavy Metal ◽

Hexavalent Chromium ◽

Low Cost ◽

High Sensitivity ◽

Sensitive Detection ◽

Toxic Heavy Metal ◽

Metal Pollutants ◽

Highly Sensitive ◽

Highly Sensitive Detection ◽

Heavy Metal Pollutants

Hexavalent chromium (Cr(vi)) is one of the most toxic heavy metal pollutants in groundwater, and thus the detection of Cr(vi) with high sensitivity, accuracy, and simplicity and low cost is of great importance.

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Amperometric sensor for ascorbic acid using a gold electrode modified with ZnO@SiO2 nanospheres

New Journal of Chemistry ◽

10.1039/c6nj00115g ◽

2016 ◽

Vol 40 (10) ◽

pp. 8438-8443 ◽

Cited By ~ 14

Author(s):

Sher Bahadar Khan ◽

Md Sameer Ahmed ◽

Abdullah M. Asiri

Keyword(s):

Ascorbic Acid ◽

Gold Electrode ◽

Low Cost ◽

Amperometric Sensor ◽

Highly Sensitive ◽

Sensitive Sensor

A highly sensitive sensor based on ZnO@SiO2 nanospheres has been developed for the detection of ascorbic acid. The developed sensor is very simple and has been fabricated using low cost materials.

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