scholarly journals Mid-IR spectroscopic instrumentation for point-of-care diagnosis using a hollow silica waveguide gas cell

2017 ◽  
Author(s):  
Daniel Francis ◽  
Jane Hodgkinson ◽  
Christopher Walton ◽  
Jeremy Sizer ◽  
Paul Black ◽  
...  
Keyword(s):  
Point Of Care ◽  
Gas Cell ◽  
Hollow Silica ◽  
Spectroscopic Instrumentation ◽  
Ir Spectroscopic

Gas Cell Infrared and Attenuated Total Reflection Infrared Spectroscopic Studies for Organic–Inorganic Interactions in Adsorption of Fulvic Acid on the Goethite Surface Generating Carbon Dioxide

2021 ◽  
pp. 000370282199121
Author(s):  
Yuki Nakaya ◽  
Satoru Nakashima ◽  
Takahiro Otsuka
Keyword(s):  
Carbon Dioxide ◽  
Activation Energy ◽  
Fulvic Acid ◽  
Spectroscopic Studies ◽  
Reaction Model ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Gas Cell ◽  
Rate Determining Step ◽  
Ir Spectroscopic

The generation of carbon dioxide (CO2) from Nordic fulvic acid (FA) solution in the presence of goethite (α-FeOOH) was observed in FA–goethite interaction experiments at 25–80 ℃. CO2 generation processes observed by gas cell infrared (IR) spectroscopy indicated two steps: the zeroth order slower CO2 generation from FA solution commonly occurring in the heating experiments of the FA in the presence and absence of goethite (activation energy: 16–19 kJ mol–1), and the first order faster CO2 generation from FA solution with goethite (activation energy: 14 kJ mol–1). This CO2 generation from FA is possibly related to redox reactions between FA and goethite. In situ attenuated total reflection infrared (ATR-IR) spectroscopic measurements indicated rapid increases with time in IR bands due to COOH and COO– of FA on the goethite surface. These are considered to be due to adsorption of FA on the goethite surface possibly driven by electrostatic attraction between the positively charged goethite surface and negatively charged deprotonated carboxylates (COO–) in FA. Changes in concentration of the FA adsorbed on the goethite surface were well reproduced by the second order reaction model giving an activation energy around 13 kJ mol–1. This process was faster than the CO2 generation and was not its rate-determining step. The CO2 generation from FA solution with goethite is faster than the experimental thermal decoloration of stable structures of Nordic FA in our previous report possibly due to partial degradations of redox-sensitive labile structures in FA.

Toward the characterization of biological toxins using field-based FT-IR spectroscopic instrumentation

2004 ◽  
Author(s):  
David W. Schiering ◽  
Robert B. Walton ◽  
Christopher W. Brown ◽  
Mark L. Norman ◽  
Joseph Brewer ◽  
...  
Keyword(s):  
Ft Ir ◽  
Spectroscopic Instrumentation ◽  
Ir Spectroscopic

“Aspirin - resistance”? A few critical considerations on definition, terminology, diagnosis, clinical value, natural course of atherosclerotic disease, and therapeutic consequences

VASA ◽  
2011 ◽  
Vol 40 (6) ◽  
pp. 429-438 ◽  
Author(s):  
Berent ◽  
Sinzinger
Keyword(s):  
Platelet Function ◽  
Point Of Care ◽  
Aspirin Resistance ◽  
Point Of View ◽  
Evidence Based ◽  
Platelet Function Tests ◽  
Clinical Value ◽  
Vascular Events ◽  
Therapeutic Consequences ◽  
Function Tests

Based upon various platelet function tests and the fact that patients experience vascular events despite taking acetylsalicylic acid (ASA or aspirin), it has been suggested that patients may become resistant to the action of this pharmacological compound. However, the term “aspirin resistance” was created almost two decades ago but is still not defined. Platelet function tests are not standardized, providing conflicting information and cut-off values are arbitrarily set. Intertest comparison reveals low agreement. Even point of care tests have been introduced before appropriate validation. Inflammation may activate platelets, co-medication(s) may interfere significantly with aspirin action on platelets. Platelet function and Cox-inhibition are only some of the effects of aspirin on haemostatic regulation. One single test is not reliable to identify an altered response. Therefore, it may be more appropriate to speak about “treatment failure” to aspirin therapy than using the term “aspirin resistance”. There is no evidence based justification from either the laboratory or the clinical point of view for platelet function testing in patients taking aspirin as well as from an economic standpoint. Until evidence based data from controlled studies will be available the term “aspirin resistance” should not be further used. A more robust monitoring of factors resulting in cardiovascular events such as inflammation is recommended.

Cloud-Computing: eHealth aus der Wolke

2018 ◽  
Vol 23 (11) ◽  
pp. 38-41
Author(s):  
Sebastian Krolop ◽  
Florian Benthin ◽  
Constanze Knahl
Keyword(s):  
Cloud Computing ◽  
Point Of Care

Cloud-Computing gewinnt auch in Kliniken zunehmend an Bedeutung. Über das Internet bereitgestellte Lösungen verändern nicht nur Verwaltung und Logistik – im klinischen Bereich geht es zum Beispiel um die Nutzung elektronischer Patientenakten am Point-of-Care.

Thrombozytenaggregationshemmer

2003 ◽  
Vol 23 (04) ◽  
pp. 181-185 ◽  
Author(s):  
H. Patscheke
Keyword(s):  
Point Of Care ◽  
Von Willebrand

ZusammenfassungUnabhängig von ihrem Wirkungsmechanismus greifen Antikoagulanzien stets unmittelbar in die Bildung und Wirkung von Thrombin und damit die Endstrecke der Gerinnung ein. Von den Aggregationshemmern hemmen nur die GPIIb/IIIa-Antagonisten die gemeinsame Endstrecke der Plättchenaggregation, indem sie die Bildung von Fibrinogen/von-Willebrand-Faktor-vermittelten Plättchen-Plättchen-Brücken hemmen.Azetylsalizylsäure (ASS), NSARs, Clopidogrel oder Ticlopidin begrenzen die Plättchenaktivierung dagegen, indem sie die Bildung bzw. Wirkung der sekundären Plättchenagonisten Thromboxan A2 bzw. ADP ausschalten, aber z. B. die durch Thrombin direkt induzierbare Plättchenaggregation nicht. Deshalb rufen ASS, Clopidogrel oder Ticlopidin allein kein wesentliches Blutungsrisiko hevor, wenn nicht weitere, die Hämostase beeinträchtigende Faktoren (z.B. ausgeprägte Thrombozytopenie, Antikoagulation) vorliegen. Deshalb entfällt für diese Hemmstoffe auch die Notwendigkeit der Therapiekontrolle. Beim therapeutischen Einsatz von ASS als Aggregationshemmer ist vielmehr die Dosierung darauf abzustellen, eine vollständige Blockade (mind. 90%) der Thromboxanbiosynthese in den Plättchen zu erreichen, um überhaupt einen therapeutischen bzw. prophylaktischen Effekt zu erzielen.Von den GPIIb/IIIa-Antagonisten sind nur die parenteral eingesetzten (Abciximab, Eptifibatid, Tirofiban) zugelassen. Orale GPIIb/IIIa-Antagonisten zeigten bisher in klinischen Studien ein erhöhtes Blutungsrisiko bei nicht ausreichendem therapeutischen Nutzen. Die meisten GPIIb/IIIa-Antagonisten verursachen eine leichte Thrombozytopenie, als deren Auslöser die Inhibitor-Rezeptor-Wechselwirkung bzw. immunologische Mechanismen diskutiert werden. Für das spezifische Monitoring dieser potenten Aggregationshemmer ist ein »Point-of-Care«-Testsystem verfügbar. Für die Einschätzung des Blutungsrisikos müssen jedoch stets alle, die Hämostase beeinflussende Faktoren berücksichtigt werden. Das gilt insbesondere, wenn neben GPIIb/IIIa-Antagonisten Heparin u.a. Wirkstoffe eingesetzt werden.

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