Cryoconcentration of flavonoid extract for enhanced biophotovoltaics and pH sensitive thin films.

Flavonoids are important value added products for dye sensitized solar cells biosensors, functional foods, medicinal supplements, nanomaterial synthesis, and other applications. Brassica oleracea contains high levels of anthocyanins in leaf sap vacuoles, and there are many viable extraction techniques that vary in terms of simplicity, environmental impact, cost, and extract photochemical/electrochemical properties. The efficiency of value added biotechnologies from flavonoid is a function of anthocyanin activity/concentration and molecule stability (i.e., ability to retain molecular resonance under a wide range of conditions). In this paper, we show that block cryoconcentration and partial thawing of anthocyanin from B. oleracea is a green, facile, and highly efficient technique that does not require any special equipment or protocols for producing enhanced value added products. Cryoconcentration increased anthocyanin activity and total phenol content approximately 10 times compared with common extraction techniques. Cryoconcentrated extract had enhanced electrochemical properties (higher oxidation potential), improved chroma, and higher UV absorbance than extract produced with other methods for a pH range of 2-12, with minimal effect on the diffusion coefficient of the extract. As a proof of concept for energy harvesting and sensor applications, dye sensitized solar cells and pH-sensitive thin films were prepared and tested. These devices were comparable with other recently published biotechnologies in terms of efficacy, but did not require expensive/environmentally detrimental extraction or concentration methods. This low cost, biorenewable, and simple method can be used for development of a variety of value added products. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:206-217, 2018.

pulSED: pulsed sonoelectrodeposition of fractal nanoplatinum for enhancing amperometric biosensor performance.

For the first time, we combine pulsed electrodeposition with out-of-phase pulsed sonication for controlled synthesis of fractal nanoplatinum structures as the transducer layer in electrochemical sensing. We develop and test this technique, called bimodal pulsed sonoelectrodeposition (pulSED), as a simple approach for creating highly conductive transducer nanometals for use in sensing and biosensing. We first compared the efficiency of pulSED nanoplatinum to other pulsed electrodeposition techniques, and then explored the effect of duty cycle and plating time on electroactive surface area and nanoparticle size/morphology. The developed pulSED nanoplatinum displayed fractal features with a relatively homogenous size distribution (26.31 ± 1.3 nm) and extremely high electroactive surface (0.28 ± 0.04 cm(2)) relative to other electroplating techniques (up to one order of magnitude higher). A high duty cycle (900 mHz) promotes formation of stable nanostructures (including fractal nanostructures) and reduces amorphous structure formation due to bubble cavitation and enhanced mass transport of metal ions to the electrode surface. To demonstrate the applicability of the pulSED technique, non-enzymatic and enzymatic sensors were developed for measuring hydrogen peroxide and glucose. The sensitivity for non-enzymatic peroxide sensing (3335 ± 305 µA cm(-2) mM(-1)), non-enzymatic glucose sensing (73 ± 14 µA cm(-2) mM(-1)) and enzymatic glucose biosensing (155 ± 25 µA cm(-2) mM(-1)) was higher than, or similar to, other nanomaterial-mediated amperometric sensors reported in the literature. The pulSED technique is a one pot method for tunable synthesis of nanometal structures as a transducer layer in electrochemical sensing and biosensing that requires no precursors or capping agents, and can be carried out at room temperature with inexpensive hardware.

Development and validation of an open source O2-sensitive gel for physiological profiling of soil microbial communities.

Community level physiological profiling is a simple, high-throughput technique for assessing microbial community physiology. Initial methods relying on redox-dye based detection of respiration were subject to strong enrichment bias, but subsequent development of a microtiter assay using an oxygen-quenched dye reduced this bias and improved the versatility of the approach. Commercial production of the oxygen microplates recently stopped, which led to the present effort to develop and validate a system using a luminophore dye (platinum tetrakis pentafluorophenyl) immobilized at the bottom of wells within a 96 well microtiter plate. The technique was used to analyze three well-characterized Florida soils: oak saw palmetto scrub, coastal mixed hardwood, and soil from an agricultural field used to grow corn silage. Substrate induced respiration was monitored by measuring respiration rates in soils under basal conditions and comparing to soils supplemented with nitrogen and various carbon sources (mannose, casein, asparagine, coumaric acid). All data was compared to a previously available commercial assay. There were no significant differences in the maximum peak intensity or the time to peak response for all soils tested (p<0.001, α=0.05). The experimental assay plates can be reused on soils up to four times (based on a deviation of less than 5%), where the commercial assay should not be reused. The results indicate that the new oxygen-based bioassay is a cost effective, open source tool for functional profiling of microbial communities.

A simple method for quantifying biomass cell and polymer distribution in biofilms.

Biofilms are ubiquitous and play an essential role in both environmental processes and hospital infections. Standard methods are not capable of quantifying biomass concentration in dilute suspensions. Furthermore, standard techniques cannot differentiate biomass composition. In this study, a user-friendly technique was developed for measuring biomass cell and polymer content in detached biofilms using a standard coulter counter. The method was demonstrated for an environmentally relevant strain of Pseudomonas aeruginosa (Schroeter) Migula grown in a bioreactor and also for a medically relevant strain of P. aeruginosa (PAO1) grown on standard growth pegs. Results were compared and validated by standard assays, including EPA method 1684 for measuring biomass, microscopic direct counts, and a crystal violet staining assay. The minimum detection limit for the coulter counter method (0.07 mg-biomass L(-1)) was significantly lower than the EPA method 1684 (1.9 ± 0.4 mg/L) and the crystal violet assay (1.1 ± 0.2 mg L(-1)). However, the coulter counter method is limited to dilute biomass samples (below 204 ± 16 mg L(-1)) due to clogging of the aperture tube. While biomass measurements are useful, the major advantage of the coulter counter method is the ability to directly determine EPS, cell, and aggregate fractions after mild chemical treatment. The rapid technique (4-5 min per sample) was used to measure biomass fractions in dispersed P. aeruginosa (Schroeter) and PAO1 biofilms. This technique will be critical for understanding biofilm formation/dispersal.

Optometric parity legislation under Medicare.

On April 1, 1987, optometrists became eligible for reimbursement under Medicare for the services optometrists are authorized to provide under the laws of the state in which this service is performed. The optometric parity language did not expand or change the current coverage and reimbursement rules, but rather expanded which providers could be reimbursed under Medicare. For the service to be covered by Medicare, the service must be one which is currently covered by Medicare if furnished by a doctor of medicine or osteopathy, and must be within the services the optometrist is authorized to perform under the licensure laws of the state in which the service is performed. Optometric parity was included as part of the Omnibus Reconciliation Act of 1986, which was signed by President Reagan on October 21, 1986.

The history of the forensic applications in radiology.

The history of progress in any field of science is related directly to technical advances which have occurred during that period. The microscope contributed immensely to the advancement of forensic investigations in the late 19th century, with its use to study trace evidence including blood, semen, soil, paint, and biological material. The application of the discovery of x-radiation by Dr. Röentgen of Würzburg, Germany, in 1895 provided an important new tool for medical practitioners throughout the world. Its application was also realized as a potential weapon by medicolegal investigators. Discovery of the location of foreign objects, including bullets, thus became a clinical as well as a forensic technique in support of the investigation of living and deceased persons. The early application of x-ray methodology in England in 1896 by Prof. Arthur Schuster of Owens College, Manchester, in a case of a gunshot wound of a woman, is described as well as some aspects of the primitive technique which were used.

Assessment of the forced expiration technique, postural drainage and directed coughing in chest physiotherapy.

The Forced Expiration Technique (FET), postural drainage (PD) and directed coughing have been evaluated in 10 patients with copious sputum (mean value 63.3 ml/24 h) with an inhaled radioaerosol method over a 30-min treatment period. FET alone and FET + PD (but not directed coughing) cleared more radioaerosol than during the control period (P less than 0.01). The wet weight of sputum obtained following FET, FET + PD and directed coughing were all significantly greater than control (P less than 0.01). However, sputum obtained by FET + PD was significantly greater than FET alone (P less than 0.05). Both FET and particularly FET + PD have been shown to be more effective than directed coughing alone and it is suggested that these manoeuvres should be incorporated into standard chest physiotherapy.

Effects of various inhalation modes on the deposition of radioactive pressurized aerosols.

The deposition of aerosol consisting of Teflon particles (mass median aerodynamic diameter 3.2 micrometers) labelled with 99Tcm has been measured in patients with obstructive airways disease. Aerosol was inhaled at 30 l min-1 with 4 s breath holding (patient group A) and at 30 l min-1 with 10 s breath holding (patient group B). A further group of patients (group C) inhaled at 90 l min-1 with 10 s breath holding. Each subject was given the aerosol during inhalation at three different lung volumes (20% VC, 50% VC and 80% VC) on three different days. The greatest whole lung, tracheobronchial and alveolar depositions occurred in group B patients, irrespective of the lung volume of aerosol actuation. By comparison, deposition was similar in groups A and C only when the aerosol was actuated at 20% VC. Whole lung deposition in groups A and B was significantly correlated both with the bronchodilator response to terbutaline sulphate aerosol administered under the same inhalation conditions and with the residence time of airborne particles in the respiratory tract. The optimum inhalation technique for a beta-adrenergic aerosol indicated by these data (slow inhalation with 10 s breath holding) confirms the results of previous studies.