scholarly journals A Normalized HLD (HLDN) Tool for Optimal Salt-Concentration Prediction of Microemulsions

2021 ◽  
Vol 11 (19) ◽  
pp. 9151
Author(s):  
Virin Kittithammavong ◽  
Ampira Charoensaeng ◽  
Sutha Khaodhiar
Keyword(s):  
Nonionic Surfactant ◽  
Optimal Condition ◽  
Empirical Equation ◽  
Type I ◽  
Mixed Surfactant ◽  
Winsor Type Iii ◽  
Model Oil ◽  
Time Required ◽  
Phase Behaviors ◽  
Mixed Systems

Optimal condition-based microemulsion is key to achieving great efficiency in oil removal. One useful empirical equation to predict an optimal condition is a hydrophilic–lipophilic deviation (HLD). However, the K constants of each surfactant should be the same to combine the HLD equations for the mixed surfactant. Recently, a normalized hydrophilic-lipophilic deviation (HLDN) was presented to avoid this limitation. This work sought to determine the phase behaviors and predict the optimal salt concentrations, using HLDN for the mixed surfactant. Sodium dihexyl sulfosuccinate (SDHS) as an anionic surfactant, and alcohol alkyl polyglycol ether (AAE(6EO4PO)) as a nonionic surfactant, were both investigated. Alkanes and diesel were used as a model oil. The results showed that AAE(6EO4PO) enforced both the hydrophilic and the hydrophobic characteristics. The Winsor Type I-III transition was influenced by the ethylene oxide, while the propylene oxide presence affected the Winsor Type III-II inversion. For the HLDN equation, the average interaction term was 1.82 ± 0.86, which markedly showed a strong correlation with the fraction of nonionic surfactant in the mixed systems. The predicted optimal salt concentrations using HLDN of SDHS-AAE(6EO4PO) in the diesel systems were close to the experimental results, with an error of <10% that is significantly beneficial due to the shorter time required for optimal determination.

A highly sensitive microsphere-based assay for early detection of Type I diabetes

TECHNOLOGY ◽  
2014 ◽  
Vol 02 (03) ◽  
pp. 200-205 ◽  
Author(s):  
Shyam Sundhar Bale ◽  
Gavrielle Price ◽  
Monica Casali ◽  
Nima Saeidi ◽  
Abhinav Bhushan ◽  
...  
Keyword(s):  
Clinical Symptoms ◽  
Type I Diabetes ◽  
Rolling Circle Amplification ◽  
Limited Range ◽  
Assay Method ◽  
Type I ◽  
Rolling Circle ◽  
Highly Sensitive ◽  
Progression Of Disease ◽  
Time Required

Type 1 Diabetes Mellitus (T1DM) is a T-cell mediated autoimmune disease in which deterioration of insulin producing pancreatic β-cells leads to a state of insulin deficiency. It has been shown that the clinical symptoms of T1DM are preceded by presence of islet cell autoantibodies (ICA) in serum. Radioimmunoassay (RIA) based detection of ICA are the current gold standard for diagnosis of T1DM. While the onset of hyperglycemia is an indicator of onset of T1DM, detection of ICA within the serum is important to differentiate T1DM from ketogenic Type 2 Diabetes (T2D) and Maturity Onset Diabetes of the Young (MODY). Due to their limited range of sensitivity, however, RIA cannot detect ICA at low concentrations in serum which could lead to delay in proper diagnosis and treatment. In addition, the use of radioactive species presents major disadvantages including exposure, waste removal, need for specialized licensed facilities to conduct the tests and the time required for the test (> 24 hours). To overcome these limitations, we have developed a rapid, highly sensitive, fluorescent and microsphere-based assay technique using Rolling Circle Amplification (RCA), to profile T1DM marker antibodies in serum. This assay utilizes the ability of RCA to detect very small amounts of DNA coupled with microsphere-immobilization resulting in an assay which is at least 50 times more sensitive than RIA. Further, this assay method requires very low volume of sample (5 μL), and can be easily adapted to detect other autoantibodies at similar sensitivities while reducing the assay time to ~6 hours. This powerful technique could enable detection of T1DM markers much earlier than current methods and enable earlier intervention to deter the progression of disease. In addition, the modularity of this assay would have implications for enhancing the sensitivities of any standard ELISA technique.

Desorption during resuspension events: Kinetic v. equilibrium model

1995 ◽  
Vol 46 (1) ◽  
pp. 251 ◽  
Author(s):  
CY Cheng ◽  
JF Atkinson ◽  
JV DePinto
Keyword(s):  
Bulk Water ◽  
Water Phase ◽  
Particulate Phase ◽  
Intraparticle Diffusion Model ◽  
Natural Systems ◽  
Wide Range ◽  
Time Required ◽  
Parameter Values ◽  
Dissolved Phase ◽  
Mixed Systems

The spills and release of hydrophobic organic chemicals (HOCs) into waterbodies have resulted in the contamination of bottom sediments. When these sediments are resuspended by runoff events or by dredging, particulate-phase contaminants desorb to the water phase. Equilibrium between the particulate phase and the dissolved phase is usually assumed for most modelling applications regardless of time scale. For well mixed systems in which chemical transport is not limited by mass transfer between the bulk water phase and sediment aggregates, an intraparticle diffusion model can be applied to estimate the time required for various HOCs to reach an equilibrium state between dissolved and particulate-phase concentrations. Calculations from this model show that total equilibrium time scales cover a wide range, from less than a day to a few hundred days. This study compares predicted suspension times for sediments of various sizes with expected equilibration times for desorption. This comparison indicates that the equilibrium assumption is not valid for a wide range of parameter values typical of natural systems. In particular, compounds with high partition coefficients, greater than about 104 mL g-1, will have minimum equilibration times of at least one to ten days. This is likely to be greater than the expected resuspension time.

scholarly journals Two-stage phase II oncology designs using short-term endpoints for early stopping

2015 ◽  
Vol 26 (4) ◽  
pp. 1671-1683 ◽  
Author(s):  
Cornelia U Kunz ◽  
James MS Wason ◽  
Meinhard Kieser
Keyword(s):  
Sample Size ◽  
Phase Ii ◽  
Interim Analysis ◽  
Type I Error ◽  
Recruitment Rate ◽  
Type I ◽  
Trial Duration ◽  
Two Stage ◽  
Oncology Trial ◽  
Time Required

Phase II oncology trials are conducted to evaluate whether the tumour activity of a new treatment is promising enough to warrant further investigation. The most commonly used approach in this context is a two-stage single-arm design with binary endpoint. As for all designs with interim analysis, its efficiency strongly depends on the relation between recruitment rate and follow-up time required to measure the patients’ outcomes. Usually, recruitment is postponed after the sample size of the first stage is achieved up until the outcomes of all patients are available. This may lead to a considerable increase of the trial length and with it to a delay in the drug development process. We propose a design where an intermediate endpoint is used in the interim analysis to decide whether or not the study is continued with a second stage. Optimal and minimax versions of this design are derived. The characteristics of the proposed design in terms of type I error rate, power, maximum and expected sample size as well as trial duration are investigated. Guidance is given on how to select the most appropriate design. Application is illustrated by a phase II oncology trial in patients with advanced angiosarcoma, which motivated this research.

Recovery time course in contractile function of fast and slow skeletal muscle after hindlimb immobilization

1982 ◽  
Vol 52 (3) ◽  
pp. 677-682 ◽  
Author(s):  
F. A. Witzmann ◽  
D. H. Kim ◽  
R. H. Fitts
Keyword(s):  
Time Course ◽  
Contractile Function ◽  
Vastus Lateralis ◽  
Type I ◽  
Shortening Velocity ◽  
Tension Development ◽  
Isometric Twitch ◽  
Time Required ◽  
Fast Muscles

Contractile properties were evaluated in rats remobilized after 6 wk of hindlimb casting to evaluate the regenerative capacity of fast and slow skeletal muscles. Contractile parameters were determined in vitro (22 degrees C) in the type I soleus (SOL), type IIA and IIB extensor digitorum longus (EDL), and the type IIB superficial vastus lateralis (SVL). Immobilization (IM) shortened the SOL isometric twitch duration after which contraction time and half-relaxation time required 4 and 7 days to recover, respectively. In contrast, IM prolonged the twitch in the EDL and SVL and recovery required 14 and 7 days, respectively. Peak tetanic tension (g/cm2) fell in the SOL and EDL with IM and full recovery required 28 days. In this regard, the SVL remained unaltered. Rates of tension development and decline remained essentially unaltered in the fast muscles after IM but fell in the SOL, requiring 14 days to fully recover. Maximal shortening velocity, which had been elevated in all three muscles by IM, recovered rapidly. The present results demonstrate that both fast and slow muscle have the ability to completely recover from 6 weeks of IM.

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