Erlotinib-Modified BODIPY Photosensitizers for Targeted Photodynamic Therapy

Photodynamic therapy (PDT) is an innovative, non-invasive and highly selective therapeutic modality for tumours and non-malignant diseases. BODIPY based molecules can function as new generation photosensitizers (PSs) in various PDT applications. Despite numerous conjugated PS systems are available, BODIPYs containing erlotinib lagged behind other photosensitizer units. In this study, smart photosensitizers containing BODIPY, erlotinib and hydrophilic units were prepared for the first time, their physicochemical properties and PDT effects were investigated. Compared with non-halogenated compound, halogenated derivatives possessed much lower fluorescence profile as well as the good ROS generation ability under red light. In vitro PDT studies were performed on both healthy (PNT1a) and prostate cancerous cells (PC3) to determine the selectivity of the compounds on cancerous cells and their effects under light. The halogenated conjugates, exposed to low dose of light illumination exhibited potent activity on cancer cell viability and the calculated IC₅₀ values proved the high phototoxicity of the photosensitizers. It was also determined that the PSs have very low dark toxicity and that the light illumination and ROS formation are required for the initiation of the cell death mechanism. As a result, erlotinib modified BODIPYs could serve as promising agents in anticancer photodynamic therapy.     

Process improvement and efficiency analysis using the Single-Minute Exchange of Dies method applied to the set-up and operation of screen-printing machines

Lean manufacturing methods are concerned with simplifying the production process and thus maximising efficiency and minimising wastage. All production processes contain several steps, which include sub-steps such as cleaning and changing devices and preparing the production areas for later steps. Most of these sub-steps require that machines are stopped and therefore they must be performed as quickly as possible. This downtime causes a decrease in efficiency, while increasing the costs and production time. Single-Minute Exchange of Dies (SMED) is a lean manufacturing strategy that has been applied successfully in many sectors to minimise excessive downtime. In this study, the SMED technique is applied in a textile screen-printing company for the case of changing the screens between each design. The steps are evaluated and designated as either external steps, which are performed without downtime, or internal steps, which take place during downtime. The number of external steps is increased while being decreased for internal steps. Also, the production time decreased by 54% and a 32% increase in efficiency was achieved during the screen-printing production of a sample t-shirt.     

Electrochemical synthesis of polypyrrole (PPy) and PPyǀmetal composites on copper electrode and investigation of their anticorrosive properties

This study reports corrosion protection behaviour of various metal cations electrodeposited onto polypyrrole (PPy) coated copper (Cu) electrode. Before electropolymerization of pyrrole, the Cu electrode was passivated in 0.1 M oxalic acid via cyclic voltammetry method. After the coating process, metal cation electrodeposition onto PPy coating was carried out in 10⁻² M CuCl₂, ZnCl₂, FeCl₂ and NiCl₂ solutions. Corrosion behaviour of uncoated, PPy and PPy|metal coated Cu electrodes was studied in 0.1 M H₂SO₄ solution by using potentiodynamic polarization, chronoamperometric and impedance spectroscopic measurements. Surface morphologies were examined by scanning electron microscope (SEM). All the electrochemical measurements were in good agreement showing that metal electrodeposited PPy coated Cu electrodes have a higher corrosion resistance. Furthermore, SEM results show that while all the samples have a homogeneous distribution of metal cations, zinc and nickel have a much better homogeneous distribution compared to copper and iron. It was found that the best corrosion protection is provided by PPy|Zn and PPy|Ni coatings and there is a significant increase in their polarization resistance with increasing amounts of electrodeposited cations.     

Preparation and characterization of polypyrrole/selenium composites

This article reports synthesis of polypyrrole (PPy) and its composites having various amounts of selenium (Se) in the presence of nitric acid in aqueous medium via chemical oxidative polymerization. Samples were spectroscopically characterized using Fourier transform infrared spectroscopy, ultraviolet‐visible spectroscopy, and atomic absorption spectroscopy. Although morphology of the samples was examined by using scanning electron microscopy (SEM), their thermal properties were studied via differential scanning calorimetry (DSC). The alternating current (ac) conductivity and dielectric properties were investigated as a function of temperature. Variation of adsorption free energy obtained from Langmuir adsorption isotherm showed that metal cations were physically adsorbed onto the polymer surface. SEM images showed that filling process significantly changes the morphology of PPy. DSC results indicated that cold crystallization temperature (T_cc) of unfilled PPy decreases with increasing filling level. Dielectric measurements showed that relaxation times for PPy and its composites have decreased linearly with increasing temperature. The conductivity of the PPy, when filled with 1 g of Se, increased ～ four times at room temperature for 1 kHz. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers     

Effect of cultivation area and climatic conditions on volatiles of virgin olive oil

To elucidate the influence of the cultivation area and climatic conditions on volatiles of virgin olive oil from Gemlik cultivar, an investigation was carried out. Five Turkish geographical zones (Bal?kesir, Ayd?n, Manisa, Antalya and Hatay) were chosen. From these areas, fruits were collected at the same maturity stage and processed using a small experimental olive oil mill, applying identical processing conditions for all olive samples. Headspace solid‐phase microextraction (HS‐SPME) technique coupled to GC/MS was used for volatile analysis. Twenty‐seven compounds were identified and characterised, representing 96.40–98.74% of the total GC area. The major volatile representing about 50% was the (E)‐2‐hexenal. This compound was found in higher concentrations on olive oils from Antalya than from Hatay area. Hexanal was the second most abundant volatile compound and varied between 13.89 and 28.96%. Comparing the olive growing areas Hatay and Antalya, the hexanal concentration was about 29 and 14%, respectively. Generally, a significant difference in the composition of volatile compounds between the oils from the same olive cultivar and from different geographic regions was recorded. The results suggest that climatic factors, latitude and longitude affect the formation of volatiles.     

Synthesis,characterization and dielectric behavior of (ES)-form polyaniline/cerium(III)-nitrate-hexahydrate composites

In this study, morphological, thermal and dielectric properties of chemically synthesized polyaniline (PANI) and its cerium(III)-nitrate-hexahydrate (Ce(NO₃)₃·6H₂O) doped composites with various doping levels were investigated. Characteristic bands of emeraldine salt (ES)-form of PANI was clearly observed in UV–visible (UV–vis) and Fourier transform infrared (FTIR) spectroscopies. Thermal analyses carried out by Differential scanning calorimetry (DSC) indicated that there was a glass transition at about 70 °C and the doping process increased thermal stability of the polymer. In the surface morphologies examined by scanning electron microscopy (SEM), various microstructures depending on the doping level were observed. Real dielectric constant exhibited a significant decrease due to the increase in the doping level especially at higher frequencies. Conductivity mechanisms of PANI and its composites were investigated by universal power law as conventional models could not provide a complete picture for all the samples. Dramatic increases up to 45, 35 and 30 times in the conductivity of 10% doped PANI were observed for 300, 350 and 400 K, respectively.     

Energy inputs and crop yield relationships in greenhouse winter crop tomato production

In this study, energy use patterns and the relationship between energy inputs and yield for single crop (winter) greenhouse tomato production were examined in Antalya province, one of the most important greenhouse centres in Turkey. Data were collected using face-to-face surveys from 85 farms producing winter greenhouse tomatoes. The results indicated that the bulk of energy was consumed in fertilizer (38.22%), electricity (27.09%), manure (17.33%) and diesel-oil (13.65%). Average yield and energy consumption were calculated as 57,905.1 kg/ha and 61,434.5 MJ/ha, respectively. Results also determined an output–input ratio of 0.8 and a respective energy productivity and specific energy of 1.061 MJ/t and 0.94 kg/MJ. In addition, the Cobb Douglas production function was applied to test the relationship among different forms of energy consumption. The findings suggested that single crop tomato producers must optimize their use of indirect energy resources. Single crop producers applied an excess use of chemicals, resulting in an inverse effect on yield as well as imposing risks to natural resources and human health. This research suggested an expansion in energy use training opportunities to greenhouse farmers in the region.     

On the mechanism of current-transport in Cu/CdS/SnO2/In-Ga structures

The structural and optical properties of CdS films deposited by evaporation were investigated. X-ray diffraction study showed that CdS films were polycrystalline in nature with zinc-blende structure and a strong (1 1 1) texture. The study has been made on the behavior of Cu/n-CdS thin film junction on SnO₂ coated glass substrate grown using thermal evaporation method. The forward bias current-voltage (I-V) characteristics of Cu/CdS/SnO₂/In-Ga structures have been investigated in the temperature range of 130-325 K. The semi-logarithmic lnI-V characteristics based on the Thermionic emission (TE) mechanism showed a decrease in the ideality factor (n) and an increase in the zero-bias barrier height (Φ_Bo) with the increasing temperature. The values of n and Φ_Bo change from 8.98 and 0.29 eV (at 130 K) to 3.42 and 0.72 eV (at 325 K), respectively. The conventional Richardson plot of the ln(I_o/T²) vs q/kT shows nonlinear behavior. The forward bias current I is found to be proportional to I_o(T)exp(AV), where A is the slope of ln(I)-V plot and almost independent of the applied bias voltage and temperature, and I_o(T) is relatively a weak function of temperature. These results indicate that the mechanism of charge transport in the SnO₂/CdS/Cu structure in the whole temperature range is performed by tunneling among interface states/traps or dislocations intersecting the space-charge region. In addition, voltage dependent values of resistance (R_i) were obtained from forward and reverse bias I-V characteristics by using Ohm's law for each temperature level.     

The effect of carbon dioxide during the desulfurization of flue gas with Mardin–Mazıdagı phosphate rock

The effects of temperature, CO₂ concentration and particle size on simultaneous calcination/sulfation of Mardin–Maz?dag? phosphate rock in fluidized-bed reactor were investigated. For this, a raw sample was exposed to calcination and sulfation processes in a fluidized-bed reactor to determine the effects of parameters by using a model gas mixture similar to the flue gas composition. The calcination ratio increased with increasing temperature and decreasing particle size, but decreased with increasing CO₂ concentration. In sulfation process, however, sulphate conversion ratio increased with increasing CO₂ ratio and decreased with decreasing particle size. The sulfation reaction is well represented by the shrinking core model and can be divided into two regions with different rate controlling step. For low conversions, the controlling step was found to be chemical reaction at the interface, but the diffusion through the product layer for high conversion. The activation energies for the chemical reaction at the interface and diffusion through the product layer cases were calculated as 100 and 296 kJ mol^?1, respectively.     

Effects of Semicontinuous and Batch System Ozonation on Wheat and Corn Starches

Wheat starch-water and corn starch-water suspensions (10%; w/w) were exposed to ozone gas by using two different contact systems; semicontinuous and batch systems. In semicontinuous contact mode, fresh ozone was applied to starch suspensions at a concentration of 4.2 mg dissolved ozone L^?1 water for 30 min, while in closed batch contact mode, starch suspensions were stirred with ozone gas at a rate of 60 g/h for 30 min. Gelatinization temperatures and enthalpies of wheat and corn starch were increased in a semicontinuous system. However, no change was observed for the gelatinization characteristics of starch samples ozonated- in batch system. Structures and birefringences of wheat and corn starch ozonated in both semicontinuous and batch operations were not differentiated clearly. Higher lightness and whiteness values were observed for both wheat and corn starch ozonated in semicontinuous system than the controls and ozonated samples in batch system. Corn starch ozonated in semicontinuous system has lower chroma and yellowness values than the others. Total color difference for the samples ozonated in semicontinuous system is significantly different from the samples ozonated in batch system. Semicontinuous ozonation system is more effective on the thermal and color properties of wheat and corn starches than the batch ozonation system.