Distribution of hydrophilic and lipophilic antibacterial drugs in skim milk,cream, and casein

This study determined the distribution of drugs to different milk fractions according to their physicochemical properties. Hydrophilic drugs tend to concentrate in skim milk, whereas lipophilic drugs tend to concentrate in cream. The concentration of a drug in casein is related to its degree of binding to milk proteins. Thus, we aimed to determine whether withdrawal time in whole milk differs from that in cream, casein, and skim milk. Amoxicillin and tylosin were selected as prototype hydrophilic and lipophilic drugs, respectively. The study was conducted in vitro and in vivo to determine whether in vitro conditions reflect the distribution of drugs in the different milk fractions in vivo. The in vivo study was conducted using a crossover design on 6 healthy Holstein dairy cattle. First, amoxicillin (i.m., single dose, 14 mg/kg) was administered to cows. Following a 1-wk washout period, tylosin (i.m., single dose, 15 mg/kg) was administered. Concentrations of amoxicillin and tylosin in milk and milk fractions were measured using HPLC-UV. In the in vitro study, 0.04 to 400 μg/g of amoxicillin and 0.05 to 50 μg/g of tylosin were spiked to drug-free milk and the concentrations in milk and milk fractions were measured. In addition, the percentage of total protein in milk and milk fractions was determined. Amoxicillin accumulated more in skim milk than in cream and casein, both in vitro (92%) and in vivo (73%, skim milk-to-whole milk ratio). The distribution of tylosin in whole and skim milk was similar to that of amoxicillin in the in vitro study, in contrast to the accumulation of tylosin in cream seen in vivo. However, the accumulation ratio of tylosin in cream was lower than expected. By either method, tylosin was less concentrated in casein than in skim milk and cream. The percentage of total protein was similar in skim milk and whole milk and higher than in cream. Thus, amoxicillin accumulates less in cream and casein, suggesting that these fractions would pose a lower risk to the consumer. Tylosin was still present at the maximum residue limit (50 μg/kg) 24 h after injection in the casein fraction and 48 h after injection in the cream fraction.     

Elaboration and Properties of Starch-Based Bio-Material Films Using Different Solvent Systems

Nowadays many studies have been focusing on the development of biomaterials obtained from renewable resources to replace fossil based plastics. The famous example is starch which is produced by a wide variety of plants as energy reserve and is available in abundance at a very competitive price. It can easily be transformed into thermoplastic starch （TPS） by addition of a plasticizer. However, TPS suffers from several limitations, such as poor mechanical properties and water sensitivity which did not permit its use in large practical applications. In this study, different formulations, containing commercial corn starch and plasticizers were prepared by the film casting method, after gelatinization of starch in hot aqueous suspensions. To obtain flexible films, two plasticizers were used： glycerol and dioctyl phthalate （DOP）. The fact that the DOP displayed an exceptionally poor water affinity, three co-solvents, methanol, ethanol and acetone were added in the aim to improve its solubility. The obtained materials were tested considering the water resistance measured at 25 and at 50 ℃, mechanical properties in tension and the differential scanning thermal analysis （DSC）. From the obtained results, it seems that the solvent system as well as the plasticizers used affects considerably the properties of the resulting materials.     

A Comparative Study for the Assessment on Blood Flow Measurement Using Self-Mixing Laser Speckle Interferometer

We study a self-mixing laser diode (SM-LD) as a low-cost compact optical sensor for noninvasive blood flow measurement over the surface of the skin. We compare the SM-LD system with a commercially available Doppler flowmeter to assess the accuracy and feasibility of the SM-LD sensors for such applications. For the SM-LD flowmeter, we apply two different signal processing methods: (1) the counting method, i.e., counting the intensity fluctuations of the signal to obtain a frequency value, and (2) the autocorrelation method, i.e., measuring the autocorrelation time of the signal. In vitro measurements show good agreement with the commercially available flowmeter. In vivo measurements performed on test subjects revealed that the autocorrelation technique shows much better results. The results of in vitro and in vivo studies and the comparison with the commercial flowmeter confirm the applicability of the SM-LD flowmeter.     

DETERMINATION OF THE EFFECT OF LEMON ADDITION UPON ELEMENT CONCENTRATIONS IN TEA

Consumption of tea is a popular tradition in Turkey. In this article, non essential and toxic element concentrations were determined in infusions and lemon added infusions in widely consumed Turkish teas (black, earl grey, and green tea). Element concentrations were found to be in the order of aluminum > nickel > barium in black and earl grey teas. In green tea, the order was changed to aluminum > nickel > lead > barium. The concentrations of arsenic and antimony were below the detection limit of the inductively coupled plasma optical emission spectrometry method employed. The addition of lemon increased aluminum, cadmium, and lead concentrations in all teas whereas nickel concentration increased in black and green tea but decreased in earl grey. The barium concentration was same at all tea samples. In comparison with the recommended daily allowance ratios, the amount of aluminum consumed is between 13.167–24.396% in males and 17.556–32.528% in females for people who consume 200 mL of teas daily. Other elements (cadmium, lead, nickel, barium) which are a concern for tea consumption were determined and the hazard index of daily tea drinking was found to be in the safe range except for green tea with lemon addition.     

Detecting single viruses and nanoparticles using whispering gallery microlasers

There is a strong demand for portable systems that can detect and characterize individual pathogens and other nanoscale objects without the use of labels, for applications in human health, homeland security, environmental monitoring and diagnostics. However, most nanoscale objects of interest have low polarizabilities due to their small size and low refractive index contrast with the surrounding medium. This leads to weak light-matter interactions, and thus makes the label-free detection of single nanoparticles very difficult. Micro- and nano-photonic devices have emerged as highly sensitive platforms for such applications, because the combination of high quality factor Q and small mode volume V leads to significantly enhanced light-matter interactions. For example, whispering gallery mode microresonators have been used to detect and characterize single influenza virions and polystyrene nanoparticles with a radius of 30 nm (ref. 12) by measuring in the transmission spectrum either the resonance shift or mode splitting induced by the nanoscale objects. Increasing Q leads to a narrower resonance linewidth, which makes it possible to resolve smaller changes in the transmission spectrum, and thus leads to improved performance. Here, we report a whispering gallery mode microlaser-based real-time and label-free detection method that can detect individual 15-nm-radius polystyrene nanoparticles, 10-nm gold nanoparticles and influenza A virions in air, and 30 nm polystyrene nanoparticles in water. Our approach relies on measuring changes in the beat note that is produced when an ultra-narrow emission line from a whispering gallery mode microlaser is split into two modes by a nanoscale object, and these two modes then interfere. The ultimate detection limit is set by the laser linewidth, which can be made much narrower than the resonance linewidth of any passive resonator. This means that microlaser sensors have the potential to detect objects that are too small to be detected by passive resonator sensors.     

A review on grain and nut deterioration and design of the dryers for safe storage with special reference to Turkish hazelnuts

Turkey produces about 80% of the total hazelnut crop of the world. About 75% of the production are exported. In Turkey hazelnuts are traditionally sun dried, and may be subject to mold growth and subsequent mycotoxin formation due to prolonged drying time under humid and rainy weather conditions. Drying hazelnuts in a reasonable time after harvest is necessary for mycotoxin-free, high-quality products. In general, nuts and cereals contaminated by the toxins pose a potential hazard not only to the people of the producer countries, but also to people of the importing countries, if they should be regarded as safe by inefficient sampling plans, therefore preventing toxin formation actually benefits very large populations. Deterioration and health hazards associated with toxin contaminated hazelnuts and other nuts and cereals have similar causes and consequences; therefore, deterioration of the nuts and cereals in storage has been reviewed by considering as many grains and nuts as possible, then special reference was made to hazelnuts. Proper preharvest practices followed by proper drying and safe storage reduces the hazards associated with contamination by the toxins. This article reviews the pre- and post-harvest practices, and the grain- and nut-drying systems required for toxin-free products. Because drying is the major unit operation involving this process, the drying systems and the mathematical models required for their design is also discussed.     

A new low band gap electrochromic polymer containing 2,5-bis-dithienyl-1H-pyrrole and 2,1,3-benzoselenadiazole moiety with high contrast ratio

A new low band gap electrochromic polymer containing of 3-(2,5-di-2-thienyl-1H-pyrrol-1-yl)-9-ethyl-9H-carbazole (SNSC) and 2,1,3-benzoselenadiazole (BSe) moiety has been reported. Structural identification of initial compounds and product were carried out by using FT-IR and ¹H NMR spectroscopy results. The resulting polymer, poly(SNSC-BSe), was completely soluble in various common organic solvents and its weight-average molecular weight (M_w) were 9420 (PDI: 1.22). According to AFM results, the RMS (root mean surface) roughness of poly-(SNSC-BSe) was found to be 48.6 nm. Besides, the thermogravimetric analysis presented that the poly(SNSC-BSe) is moderately stable against to thermal effect with the initial degradation temperature at 182 °C. The lowest energy transition band maxima of poly(SNSC-BSe) was 498 nm in thin film and the optical band gap calculated from the onset wavelength of the optical absorption was 1.77 eV. On the other hand, the electrochemical band gap calculated from oxidation and reduction onset values was 1.60 eV, respectively. Finally, the electrochromic performance of the polymer film represents a high contrast ratio in the NIR region (51%), fast response time of about 1 s, high coloration efficiency (274 cm² C⁻¹) and retained its performance by 94.6% even after 1000 cycles.     

Sunflower seed cake as reinforcing filler in thermoplastic composites

Dimensional stability, mechanical properties, and melting and crystallization behavior of polypropylene composites filled with sunflower seed cake (SSC) were investigated. Injection molded composites were prepared from the SSC flour and polypropylene with and without maleic anhydride‐grafted polypropylene (MAPP) at 30, 40, 50, and 60 wt % contents of the SSC flour. Twenty‐eight days thickness swelling and water absorption values of the specimens increased by 43 and 56% as the filler content increased from 30 to 60 wt %, respectively. The flexural modulus of the polypropylene composites increased from 3157 to 4363 MPa as the SSC flour increased from 30 to 60 wt %. The maximum flexural strength 38.4 MPa was observed for 40 wt % SSC flour filled specimens. However, further increment in the SCC flour decreased the flexural strength to 31.4 MPa. The tensile strength of the specimens decreased from 22.5 to 14 MPa while the tensile modulus increased from 3023 to 3677 MPa as the SSC flour increased from 30 to 60 wt %. The dimensional stability and mechanical properties of the composites were significantly improved by the incorporation of the coupling agent (MAPP). The effect of the MAPP addition was more pronounced for the strength than for the modulus. The melting temperature and degree of crystallinity of the neat polypropylene decreased with increasing content of the SSC flour. The degree of crystallinity of filled composites considerably increased with the incorporation of the MAPP. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Physical,mechanical, and thermal properties of polypropylene composites filled with walnut shell flour

Injection molded specimens were prepared from the walnut shell flour and polypropylene with and without maleic anhydride-grafted polypropylene at 40, 50, and 60% (weight) contents of the walnut shell. The bending and tensile modulus of the composites significantly increased with increasing the filler content while the bending and tensile strengths significantly decreased. Water absorption and thickness swelling of the composites increased with increasing filler content. The MAPP improved the interfacial adhesion between walnut shell flour and polymer matrix. A 40/57/3 formulation of the walnut shell flour/polypropylene/MAPP can be used in outdoor applications requiring a high dimensional stability.     

Preparation and properties of nano diamond/6F‐bisphenol A‐based cyanate ester composites

The aim of this study was to improve thermal conductivity, thermal stability, and mechanical properties of bisphenol A dicyanate ester (BADCy) by adding bisphenol A dicyanate ester containing fluorine (F‐BADCy) and nano diamond. The cyanate esters containing fluorine/nano diamond composites having various ratios of BADCy, F‐BADCy, and nano diamond were prepared. Thermal stability and thermal conductivity of the samples were evaluated by thermogravimetric analysis, differential scanning calorimetry and laser flash method, respectively. The samples were characterized with the following analysis; gel content, water absorption capacity, and stress‐strain test. Hydrophobicity of the samples was determined by the contact angle measurements. Moreover, the surface morphology of the samples was investigated by a scanning electron microscopy (SEM). The obtained results prove that the cyanate ester containing fluorine/nano diamond composites have good thermal and mechanical properties and they can be used in many applications such as electronic devices, materials engineering, and other emergent. POLYM. COMPOS., 34:1977–1985, 2013. © 2013 Society of Plastics Engineers