Medium's conductivity and stage of growth as crucial parameters for efficient hydrocarbon extraction by electric field from colonial micro-algae.

The green algae Botryococcus braunii produces a high amount of extracellular hydrocarbon, making it a promising algae in the field of bio-fuels production. As it mainly produces squalene like hydrocarbons, cosmetic industries are also interested in its milking. Pulsed electric fields (PEF) are an innovative method allowing oil extraction from micro-algae. In common algae accumulating hydrocarbon inside cytoplasm (Chlorella vulgaris, Nannochloropsis sp., etc), electric fields can destroy cell membranes, allowing the release of hydrocarbon. However, for B.braunii, hydrocarbons adhere to the cell wall outside of cells as a matrix. In a previous article we reported that electric fields can unstick cells from a matrix, allowing hydrocarbon harvesting. In this work, we deeper investigated this phenomenon of cell hatching by following 2 parameters: the conductivity of the medium and the cultivation duration of the culture. Cell hatching is accurately evaluated by both microscopic and macroscopic observations. For high conductivity and a short time of cultivation, almost no effect is observed even after up to 1000 PEF pulses are submitted to the cells. While lower conductivity and a longer cultivation period allow strong cell hatching after 200 PEF pulses are applied to the cells. We identify 2 new crucial parameters, able to turn the method from inefficient to very efficient. It might help companies to save energy and money in case of mass production.

A new mechanism for efficient hydrocarbon electro-extraction from Botryococcus braunii.

BACKGROUND: Recent understanding that specific algae have high hydrocarbon production potential has attracted considerable attention. Botryococcus braunii is a microalga with an extracellular hydrocarbon matrix, which makes it an appropriate green energy source. RESULTS: This study focuses on extracting oil from the microalgae matrix rather than the cells, eliminating the need for an excessive electric field to create electro-permeabilization. In such a way, technical limitations due to high extraction energy and cost can be overcome. Here, nanosecond pulsed electric fields (nsPEF) with 80 ns duration and 20-65 kV/cm electric fields were applied. To understand the extraction mechanism, the structure of the algae was accurately studied under fluorescence microscope; extraction was quantified using image analysis; quality of extraction was examined by thin-layer chromatography (TLC); and the cell/matrix separation was observed real-time under a microscope during nsPEF application. Furthermore, optimization was carried out by screening values of electric fields, pulse repetition frequencies, and energy spent. CONCLUSIONS: The results offer a novel method applicable for fast and continues hydrocarbon extraction process at low energy cost.

Evaluation of Salivary Secretory Immunoglobulin A Levels in Diabetic Patients and Association with Oral and Dental Manifestations.

OBJECTIVES: Oral and dental manifestations in diabetic patients can arise due to numerous factors, including elevated salivary secretory immunoglobulin A (s-IgA) levels. This study aimed to evaluate s-IgA concentrations in patients with type 2 diabetes mellitus (T2DM) and to investigate the association between s-IgA levels and oral and dental manifestations of T2DM. METHODS: This cross-sectional descriptive study was carried out between October 2011 and September 2012 in Kerman, Iran, and included 260 subjects (128 patients with T2DM and 132 healthy controls). Unstimulated salivary samples were collected from all subjects and s-IgA levels were determined using the immunoturbidimetric method. The oral cavities and teeth of T2DM patients were evaluated for oral and dental manifestations. RESULTS: Both diabetic and control subjects with higher concentrations of s-IgA had significantly higher numbers of decayed, missing or filled teeth (DMFT) and periodontal index (PDI) scores (P <0.050). s-IgA levels were significantly higher in subjects with oral candidiasis (P <0.050). Among diabetic patients, significantly higher s-IgA levels were concomitant with xerostomia and denture stomatitis (P ≤0.050). There were no significant differences between s-IgA concentrations and other oral or dental manifestations in either group. CONCLUSION: Individuals with a greater number of DMFT, a higher PDI score and oral candidiasis had significantly higher s-IgA levels. s-IgA levels were not significantly higher among diabetic patients in comparison to the control group. However, significantly higher s-IgA levels occurred with xerostomia and denture stomatitis in diabetic patients. In addition, s-IgA was significantly higher in patients with uncontrolled diabetes compared to those with controlled diabetes.

Relationship between the elongated styloid process in panoramic radiographs and some of the general health conditions in patients over 40 years of age in the Iranian population.

BACKGROUND: The styloid process and the attached ligaments have the potential for calcification and ossification in specific conditions. The purpose of this study was to evaluate the relationship between the elongated styloid process (ESP) frequency and some of the systemic health factors of patients over 40 years of age. MATERIALS AND METHODS: In this analytical-descriptive study, 296 panoramic radiographs of patients over 40 years of age (165 female and 131 male) referred to the Dental School of Khorasgan Azad University were selected. The length of the styloid process was measured by a special ruler and recorded in a questionnaire form. Other data such as sex, age, height, weight, blood pressure, heartbeat and the number of teeth present in the mouth were also recorded. The lengths equal to or more than 30 mm on the radiographs were considered as ESP. Data analysis were done by independent t-test, Pearson correlation coefficient and Chi-square test at a significance level of < 0.05. RESULTS: ESP was observed in 135 cases (45.6%). There was a significant relationship between ESP and the body height, weight and the blood pressure, but there was no significant correlation between ESP, the heartbeat and the number of teeth present in the mouth. CONCLUSION: Because of the significant relationship between the length of the styloid process and the blood pressure, height and weight it is reasonable to evaluate a patient's systemic health conditions when radiographic signs of ESP are observed.