Injection level dependence of the gain, refractive index variation, and alpha (α) parameter in broad-area InGaAs deep quantum-well lasers

In this study, a single, simple and an accurate computer-aided design model is developed in order to obtain the injection level dependence of the critical quantities of broad-area (with a width of 50 μm or more) InGaAs deep quantum-well (QW) lasers. Each of these quantities (gain, refractive index variation, and alpha (α) parameter) requires lengthy mathematical calculations with the use of different theories, assumptions, approximations, and estimations of some parameter values. The model is based on artificial neural network (ANN) approach that the total computational time is in the order of microseconds for the whole quantities in order to get their accurate values. The results are in very good agreement with the previously obtained results from an InGaAs deep QW laser sample.     

Mechanical reinforcement and water repellency induced to cellulose sheets by a polymer treatment

The present study reports a simple method to control the mechanical and surface properties of cellulose fiber networks and to protect them from humidity, without altering their initial morphology. This is achieved by dip coating the fiber networks in solutions containing different amounts of ethyl cyanoacrylate monomer (ECA). Under ambient humidity and due to the presence of the -OH groups of the cellulose, the ECA polymerizes around each individual cellulosic fiber forming a thin poly(ethyl cyanoacrylate) (PECA) shell. PECA was found to interact with the cellulose surface via hydrogen bonding as evidenced by Fourier transform infrared spectroscopy and thermogravimetric analysis measurements. The detailed surface characterization reveals that only 3.5 wt% of ECA in solution is sufficient to form compact PECA cladding around every cellulose fiber. After the proposed treatment the cellulose sheets become hydrophobic, well protected from the environmental humidity and with increased Young’s modulus.     

Modification of wetting properties of laser-textured surfaces by depositing triboelectrically charged Teflon particles

Hydrophilic laser-textured silicon wafers with natural oxide surfaces were rendered hydrophobic by depositing electrostatically charged submicrometer Teflon particles, a process termed as triboelectric Teflon adhesion. Silicon surfaces were micro-textured (～5 μm) by laser ablation using a nanosecond pulsed UV laser. By varying laser fluence, micro-texture morphology of the wafers could be reproduced and well controlled. Wetting properties of the triboelectrically charged Teflon-deposited surfaces were studied by measuring apparent static water contact angles and water contact angle hysteresis as a function of substrate roughness and the amount of Teflon deposited. A similar study was also performed on various micro-textured silicon carbide surfaces (sandpapers). If the average substrate roughness is between 15 and 60 μm, superhydrophobic surfaces can be easily formed by Teflon deposition with water contact angle hysteresis less than 8°. This environmentally benign solvent-free process is a highly efficient, rapid, and inexpensive way to render contact-charged rough surfaces hydrophobic or superhydrophobic.     

Underwater saturation resistance and electrolytic functionality for superhydrophobic nanocomposites

In the current study, water immersion saturation characterization and saturation resistance are investigated for various superhydrophobic polymer nanocomposite coatings. Two different diagnostic methods are used to characterize superhydrophobic performance longevity under continuous water contact: optical reflectivity (associated with captured air layer) and static contact angle (measured immediately after an immersion period). The results indicate that retention of optical reflectivity and superhydrophobicity vary significantly among coatings, and that superhydrophobicity can be lost within a few minutes whereas optical reflectivity can be maintained for hours. Novel electrolytic reactions on electroconductive polymeric nanocomposites can extend superhydrophobic duration by 400 %.     

Diethylstilbestrol glucuronide (DESG): synthesis, labeling with radioiodine and in vivo/in vitro evaluations

Diethylstilbestrol (DES) is a synthetic non-steroidal estrogen, pharmacologic effects of which resemble natural estrons; today it is being used to treat some types of postmenopausal breast cancer and advanced prostate cancer. The aim of current study is conjugation of glucuronic acid (G) to DES and to evaluate radiopharmaceutical potential of this estrogen glucuronide derivative (DESG) which is specific to β glucuronidase enzyme consisting tumor cells. Taking into consideration the compatibility to the chemical structures of the synthesized product, ¹³¹I and ¹²⁵I were chosen as the appropriate radionuclides and DESG was labeled with these radionuclides utilizing iodogen method. The radiochemical yields of ^125/131I-DESG were over 90 % according to thin layer radio chromatography method. The biodistribution of ¹³¹I-DESG in healthy female Wistar Albino rats has been investigated and the range of the breast/blood and breast/muscle ratios were approximately 2 and 13 in 240 min for ER unsaturated studies. Effects of the radioiodinated DES and DESG on the cells were examined using MCF-7, A-549, Caco-2 cell lines. ¹²⁵I-DESG has higher incorporation percentages than ¹²⁵I-DES on MCF-7 cells. The radioiodinated DESG has the desired radiopharmaceutical properties which could be candidate radiopharmaceuticals for diagnosis and especially radionuclide therapy of breast tumors.     

Application of a parallel genetic algorithm to the global optimization of medium-sized Au–Pd sub-nanometre clusters

To contribute to the discussion of the high activity and reactivity of Au–Pd system, we have adopted the BPGA-DFT approach to study the structural and energetic properties of medium-sized Au–Pd sub-nanometre clusters with 11–18 atoms. We have examined the structural behaviour and stability as a function of cluster size and composition. The study suggests 2D–3D crossover points for pure Au clusters at 14 and 16 atoms, whereas pure Pd clusters are all found to be 3D. For Au–Pd nanoalloys, the role of cluster size and the influence of doping were found to be extensive and non-monotonic in altering cluster structures. Various stability criteria (e.g. binding energies, second differences in energy, and mixing energies) are used to evaluate the energetics, structures, and tendency of segregation in sub-nanometre Au–Pd clusters. HOMO–LUMO gaps were calculated to give additional information on cluster stability and a systematic homotop search was used to evaluate the energies of the generated global minima of mono-substituted clusters and the preferred doping sites, as well as confirming the validity of the BPGA-DFT approach.     

Automated Antibody De Novo Sequencing and Its Utility in Biopharmaceutical Discovery

Applications of antibody de novo sequencing in the biopharmaceutical industry range from the discovery of new antibody drug candidates to identifying reagents for research and determining the primary structure of innovator products for biosimilar development. When murine, phage display, or patient-derived monoclonal antibodies against a target of interest are available, but the cDNA or the original cell line is not, de novo protein sequencing is required to humanize and recombinantly express these antibodies, followed by in vitro and in vivo testing for functional validation. Availability of fully automated software tools for monoclonal antibody de novo sequencing enables efficient and routine analysis. Here, we present a novel method to automatically de novo sequence antibodies using mass spectrometry and the Supernovo software. The robustness of the algorithm is demonstrated through a series of stress tests.

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In vitro evaluation of radiolabeled (125I) methanol extracts of yarrow in cell lines of MCF-7, PC-3, A-549 and Caco-2

Nowadays, cancer is still the second leading cause of death all over the world. Therefore, natural products which have anticancer and antitumor properties are come into prominence. Achillea family is known with anticancer and antitumor activity. Yarrow which has over a hundred bioactive compounds is a member of Achillea family. In current study; components of yarrow which was obtained after methanol extraction and purification were radiolabeled with ¹²⁵I and effects of these radiolabeled components on the cells were examined with using Caco-2, MCF-7, A-549, PC-3 cell lines. As a result of these studies, seven peaks were obtained and the highest radiolabeling yield was calculated for ¹²⁵I radiolabeled Peak 7 (95.00 ± 7.07, n = 4). To screen the biological properties of these radiolabeled peaks at determined cell lines, our ongoing effort was to evaluate incorporation percentage with time dependent. Furthermore, ¹²⁵I-Peak 7 had highest incorporation ratio for whole cell lines and its incorporation percentage was increased with time dependent. Results of these in vitro studies were compatible with previous in vivo studies and traditional use of yarrow plants.     

Investigation of in vitro efficiency of magnetic nanoparticle-conjugated <Superscript>125</Superscript>I-uracil glucuronides in adenocarcinoma cells

Modification of the magnetic properties of a drug can be used to direct the drug to the desired site, enhancing its therapeutic effectiveness and reducing side effects. In this study, surface-modified magnetic nanoparticles were immobilized with uracil glucuronide derivatives and then labeled with I-125. The morphology, structure, and composition of the magnetic particles were examined by TEM, SEM, VSM, and XRD. The particles sizes were about 50 nm. The labeling yield was 93.8% for uracil-O-glucuronide-immobilized magnetic particles and 95.0% for uracil-N-glucuronide-immobilized magnetic particles. The cell incorporation rates of N- and O-glucuronides were higher than those of uracil. The incorporation rates of uracil-, O-glucuronide-, and N-glucuronide-conjugated magnetic particles were all high. The cell incorporation rates of ligand-conjugated magnetic particles increased under a magnetic field.