A General Treatment of Solubility 4. Description and Analysis of a PCA Model for Ostwald Solubility Coefficients

Article discussing a general treatment of solubility and a description and analysis of a principal component analysis (PCA) model for Ostwald solubility coefficients

A General Treatment of Solubility. 3. Principal Component Analysis (PCA) of the Solubilities of Diverse Solutes in Diverse Solvents

Article discussing a general treatment of solubility and principle component analysis (PCA) of the solubilities of diverse solutes in diverse solvents

Keemiliste ja bioloogiliste omaduste mitmemõõtmeline analüüs

Väitekirja elektrooniline versioon ei sisalda publikatsioone.Käesoleva dissertatsiooni esimeses osas on antud kirjanduse ülevaade uuritud omadustest, milleks on lahustuvus kui ainete fundamentaalne omadus, läbitavus kui ravimiarenduses oluline ainete absorbtsiooni kirjeldav omadus ning tõrje aeg kui sääsetõrje vahendite efektiivsust kirjeldav omadus. Käsitletakse kasutatud omaduste teoreetilist baasi ja praktilist väljundit. Samuti on toodud kasutatud metoodika teoreetilised põhimõtted ning praktilised kasutusnäited. Teises osas on kokku võetud dissertatsiooni raames tehtud uurimustöö kus analüüsiti keemilisi ja bioloogilisi omadusi mitmemõõtmeliste analüüsi meetoditega. Analüüsiti orgaaniliste ühendite lahustuvust, kui ainete fundamentaalset omadust PCA ja QSPR meetoditega. Säärane uudne meetodite kombinatsioon tõi välja olulised strukturaalselt karakteristikud, mis mõjutavad lahustuvust. Need karakteristikud seostati solvatatsiooni vabaenergia liikmetega. Lõplik mudel hõlmab 98.6% kogu andmete informatsioonist. Mustrite analüüs tõi välja kaks peamist interaktsiooni tüüpi. Mittespetsiifilised interaktsioonid, mis hõlmavad endas molekuli suurusest sõltuvaid interaktsioone. Spetsiifilise interaktsioonid, mis koondavad enda alla polaarsusest, elektrostaatikast ja vesiniksidemest tingitud interaktsioone. Uuriti ravimite läbitavust fosfolipiidsest membraanist, kus saadud viie-parameetrilise QSAR mudeli molekulaardeskriptorid kirjeldavad membraani läbitavuse olulisi karakteristikuid nagu vesinikside, laengujaotus, polariseeritavus ja molekuli kuju. Samuti uuriti sääsetõrje vahendite efektiivsust, kus saadud nelja-parameetrilise QSAR mudeli molekulaardeskriptorid kirjeldavad kolme olulist tõrjevahendi efektiivsust mõjutavat karakteristikut: aine aurustumine, strukturaalne sobivus retseptoriga ning keemiline interaktsioon retseptoriga. Dissertatsioonis on edukalt rakendatud QSPR/QSAR ja PCA mitmemõõtmelisi analüüsi meetodeid kus saadud mudelid, nende valideerimine ja diagnostika omavad häid statistilisi karakteristikuid ning näitavad mudelite rakendatavust. Mudelite mehhanistlikud interpretatsioonid on kooskõlas toimuvate keemiliste ja bioloogiliste protsessidega ning seletavad keemiliste ühendite käitumist keskkonnas antud protsesside raames.Solubility as a fundamental property in chemistry and biology was studied using PCA and QSPR methodologies. Such combination of these methods as a new approach was described and a general scheme was provided. The study revealed important structural characteristics influencing solubility and their relationships with solvation free energy terms was discussed. Pattern analysis revealed two general types of interactions. Also, the pharmacologically important oral bioavailability of drugs was studied. A resulting QSAR model provides insight into the structural parameters that influence and determine the mechanism of permeability. Mosquito repellent activity was studied using QSAR methodology. Three important mechanistic characteristics were discussed

Thermal Analysis of a Disposable, Instrument-Free DNA Amplification Lab-on-a-Chip Platform

Novel second-generation rapid diagnostics based on nucleic acid amplification tests (NAAT) offer performance metrics on par with clinical laboratories in detecting infectious diseases at the point of care. The diagnostic assay is typically performed within a Lab-on-a-Chip (LoC) component with integrated temperature regulation. However, constraints on device dimensions, cost and power supply inherent with the device format apply to temperature regulation as well. Thermal analysis on simplified thermal models for the device can help overcome these barriers by speeding up thermal optimization. In this work, we perform experimental thermal analysis on the simplified thermal model for our instrument-free, single-use LoC NAAT platform. The system is evaluated further by finite element modelling. Steady-state as well as transient thermal analysis are performed to evaluate the performance of a self-regulating polymer resin heating element in the proposed device geometry. Reaction volumes in the target temperature range of the amplification reaction are estimated in the simulated model to assess compliance with assay requirements. Using the proposed methodology, we demonstrated our NAAT device concept capable of performing loop-mediated isothermal amplification in the 20–25 °C ambient temperature range with 32 min total assay time

Integrated self-regulating resistive heating for isothermal nucleic acid amplification tests (NAAT) in Lab-on-a-Chip (LoC) devices

<div><p>Isothermal nucleic acid amplification tests (NAAT) in a Lab-on-a-Chip (LoC) format promise to bring high-accuracy, non-instrumented rapid tests to the point of care. Reliable rapid tests for infectious diseases allow for early diagnosis and treatment, which in turn enables better containment of potential outbreaks and fewer complications. A critical component to LoC NAATs is the heating element, as all NAAT protocols require incubation at elevated temperatures. We propose a cheap, integrated, self-regulating resistive heating solution that uses 2xAAA alkaline batteries as the power source, can maintain temperatures in the 60–63°C range for at least 25 minutes, and reaches the target range from room temperature in 5 minutes. 4 heating element samples with different electrical characteristics were evaluated in a thermal mock-up for a LoC NAAT device. An optimal heating element candidate was chosen based on temperature profiling. The optimal candidate was further evaluated by thermal modelling via finite element analysis of heat transfer and demonstrated suitable for isothermal nucleic acid amplification.</p></div

Design parameters for self-regulating PTC polymer heaters from Heatron Inc.

<p>Design parameters for self-regulating PTC polymer heaters from Heatron Inc.</p