119 research outputs found
Enhanced anticancer potency with reduced nephrotoxicity of newly synthesized platin-based complexes compared with cisplatin
No full textAs a platinum-containing anticancer drug, cisplatin is the keystone for treating many malignancies. Nephrotoxicity is the main dose-limiting toxicity, and several hydration therapies and supplementary strategies are utilized to reduce cisplatin-induced kidney damage, so the discovery and development of effective and safe antitumor drugs are still on the path of human health. Herein, a new four-coordinated Pt complex [Pt(TSC)Cl] using N(4)-phenyl-2-formylpyridine thiosemicarbazone (HTSC) was synthesized and characterized by single-crystal X-ray diffraction, (1)HNMR, FT-IR, LC/MS and CHN elemental analysis. The Pt(TSC)Cl complex revealed antiproliferative activity against A549, MCF-7 and Caco-2 cell lines with a low micromolar IC(50) (200–1.75 µM). Specifically, the Pt(TSC)Cl complex displayed more selectivity in Caco-2 cells (IC(50) = 2.3 µM) than cisplatin (IC(50) = 107 µM) after 48 h of treatment. Moreover, compared with cisplatin, a known nephrotoxic drug, the Pt(TSC)Cl complex exhibited lower nephrotoxicity against Hek293 normal cells. We also found that the Pt(TSC)Cl complex can effectively prevent cancer cell propagation in sub-G1 and S phases and induce apoptosis (more than 90%). Real time PCR and western analysis demonstrated that the expression pattern of apoptotic genes and proteins is according to the intrinsic apoptosis pathway through the Bax/Bcl-2-Casp9-Casp3/Casp7 axis. Collectively, our findings indicated that the Pt(TSC)Cl complex triggers apoptosis in Caco-2 cell lines, while low nephrotoxicity was shown and may be considered a useful anticancer drug candidate for colorectal cancers for further optimization and growth
Toward Real-Time Image Annotation Using Marginalized Coupled Dictionary Learning
Full text linkIn most image retrieval systems, images include various high-level semantics,
called tags or annotations. Virtually all the state-of-the-art image annotation
methods that handle imbalanced labeling are search-based techniques which are
time-consuming. In this paper, a novel coupled dictionary learning approach is
proposed to learn a limited number of visual prototypes and their corresponding
semantics simultaneously. This approach leads to a real-time image annotation
procedure. Another contribution of this paper is that utilizes a marginalized
loss function instead of the squared loss function that is inappropriate for
image annotation with imbalanced labels. We have employed a marginalized loss
function in our method to leverage a simple and effective method of prototype
updating. Meanwhile, we have introduced regularization on semantic
prototypes to preserve the sparse and imbalanced nature of labels in learned
semantic prototypes. Finally, comprehensive experimental results on various
datasets demonstrate the efficiency of the proposed method for image annotation
tasks in terms of accuracy and time. The reference implementation is publicly
available on https://github.com/hamid-amiri/MCDL-Image-Annotation.Comment: @article{roostaiyan2022toward, title={Toward real-time image
annotation using marginalized coupled dictionary learning},
author={Roostaiyan, Seyed Mahdi and Hosseini, Mohammad Mehdi and Kashani,
Mahya Mohammadi and Amiri, S Hamid}, journal={Journal of Real-Time Image
Processing}, volume={19}, number={3}, pages={623--638}, year={2022},
publisher={Springer}
Infraspecific variations in essential oil and glandular trichomes in Nepeta heliotropifolia
No full textYarmoohammadi M, Talebi SM, Nohooji MG. 2017. Infraspecific variations in essential oil and glandular trichomes in Nepeta heliotropifolia. Biodiversitas 18: 964-970. Nepeta heliotropifolia Lam. (Labiatae) is one of the perennial medicinal and aromatic plants, naturally grows in different regions of Iran. The essential oil composition of aerial parts and also the micromorphology and distribution of foliar trichomes of N. heliotropifolia from two different regions of Iran were studied. The extracted essential oils were significantly composed of caryophyllene oxide and phytol, which were quantified by GC and identified based on their GC/MS spectra. The essential oil compositions differed greatly with habitat as well as former investigations. Phytol was quantified between 0.75-10. 29% of the total essential oil, but caryophyllene oxide was quantified between 3.90-12.17% of the total essential oil. Trichomes investigations showed that leaves bear an indumentum of glandular and non-glandular hairs. Two main kinds of glandular trichomes were observed; peltate and capitate. The numbers of capitate and peltate trichomes varied between populations. Such great differences in the essential oil composition may be attributed to chemotype creation and also an adaptation of these populations to particular habitats.</jats:p
Acoustic and electrical properties of bismuth sodium titanate-based materials
No full textIn this research, an attempt has been made to develop and characterize lead-free ceramics, transducers, and thin films based on Bi0.5Na0.5TiO3 (BNT) compositions. BNT-based ceramics with different compositions were prepared by mixed oxide route. The electromechanical and acoustic properties of the ceramics were studied. 0.88BNT-0.08BKT-0.04BT (BNKTBT88) and 0.076BNT-0.20BKT-0.04BLT (BNKLT76) ceramics showed relatively high values of piezoelectric coefficient (d33~170-175 pC.N-1), dielectric constant (850-950), and planar coupling coefficient (kp~0.32-0.37). On the other hand, BNKLT88 ceramics with a rhombohedral structure exhibited high mechanical quality factor (Qm~420). Acceptor dopants such as Mn and Fe were doped in BNKLT88 ceramics. By optimizing the powder processing and sintering temperature, Qm values as high as 900-975 were obtained in 1.5 mol.% Fe or Mn-doped ceramics sintered at 1100 oC. This composition showed the maximum vibration velocity (0.6 m.s-1), minimum heat generation, minimum input power, and the best efficiency among the studied compositions. High frequency ultrasonic transducers for medical imaging were designed and fabricated based on the BNKLT88 ceramics. The focused transducer with a center frequency of 23 MHz, exhibited a -6dB bandwidth and insertion loss of 55% and -32.1 dB, respectively. B-mode images of a wire phantom (30 µm in diameter) were produced by the transducer. BNT-based thin films with four different compositions in BNT-BKT-BT as well as BNT-BKT-BLT systems were deposited on (001)-oriented SrRuO3/SrTiO3 substrates by pulsed laser deposition technique. The effects of deposition parameters on the microstructure, chemical composition, and electrical properties of thin films were evaluated. Under optimized condition, BNKTBT88 thin films exhibited a remnant polarization of about 30 μC.cm-2 and coercive field of 85 kV.cm-1. The dielectric constant and loss tangent at 1 kHz were measured to be 645 and 0.052, respectively. The leakage current of epitaxial BNKTBT88 thin films measured at different temperatures was matched with the Lampert’s triangle bounded by three straight lines of different slopes. It was shown Mn-doping suppressed the leakage current by more than two orders of magnitude. The remnant polarization and dielectric constant (at 10 kHz) of Mn-doped BNKLT76 film deposited at 400 mtorr were measured to be 23 µC.cm-2 and 660, respectively.Ph. D.Includes bibliographical referencesIncludes vitaby Seyed Mehdi Hejazi Dehaghan
Strategies to Enhance Thin Film Silicon Solar Cell Efficiency
No full textThin-film silicon solar cells are an innovative approach to utilizing solar energy. Thanks to their flexibility, lower material usage, and production cost, they have the potential to be used in a range of applications. The conversion efficiencies of thin-film silicon solar cells need to be improved to make them commercially viable. This involves further optimizing the different layers of the solar cells. During this project, different strategies for enhancing thin film silicon solar cells were studied, including the deposition conditions for nc-Si:H layer, the sacrificial texturing used, the use of an additional back reflector layer, and the type of TCO layer used. A more consistent quality of the nc-Si:H samples were obtained by varying the hydrogen flow rate compared to the silane flow rate in the processing chamber. Using a silane flow rate of 2.3 sccm and a hydrogen flow rate of 120 sccm, a silane concentration 2.6 was achieved, resulting in nc-Si:H layer with a crystallinity of 60%, close to the desired amorphous-nanocrystalline silicon transition region. The texturing used in the glass sample can play a significant role in scattering the incident light into the solar cell. Craters of different sizes are formed depending on the material used for the sacrificial layer. Making smaller craters on top of larger craters using modulated surface textures (MST) is also possible. Using intrinsic Zinc Oxide (i-ZnO) sacrificial texturing resulted in the highest spectral utilization in single junction nc-Si: H with a Jsc of 25.2 mA/cm2. Indium-doped tin oxide (ITO) sacrificial texturing created micro-sized textures, resulting in the highest spectral utilization in micromorph samples (Jsc of 24.6 mA/cm2). Using an MST of ITO and i-ZnO also resulted in high spectral utilization with a Jsc of 24.3 mA/cm2 in micromorph cells Having an additional back reflector on top of the metal back contact can further improve photon absorption in solar cells. Using a material with a low refractive index, such as i-ZnO, increased the spectral utilization and improved the short-circuit current (Jsc) by approximately 10%. Depositing the i-ZnO back reflector layer using a higher heater temperature (300°C), improved the spectral utilization of the sample further by 9% The transparent conductive oxide (TCO) layer must be highly transparent and conductive. Usually, ITO is used as a TCO layer, although it has limited absorption in the infrared region and lower conductivity at higher temperatures. A TCO with higher optoelectrical properties was obtained using a bilayer of hydrogenated indium oxide (IOH) and i-ZnO. nc-Si:H samples with the TCO bilayer showed a higher spectral utilization and an improvement in their Jsc by 9-12%. The performance of micromorph samples with TCO bilayer was also higher with Jsc improvement of 6%. The influence of the bilayer thickness on the performance of micromorph samples was also inspected, and it was found that using a thicker bilayer with a thickness of 1100 nm instated of 600nm boosted the performance of the sample further and improved its Jsc by 3%.Electrical Engineering | Sustainable Energy Technolog
Infraspecific essential oil and anatomical variations of Salvia nemorosa L. (Labiatae) populations in Iran
No full textQualitative Research
No full textOne of the most important problems in organization and management research is uncompatibility of subject and research method. Traditionally researchers of management and organization have used research methods of natural sciences to explore the unknown of organizations. In this article, author tries to introduce Qualitative Research as an appropriate approach to solve the mentioned problem. Nature, data collection methods, and Trys of Qualitative Research are main sections of present article. The author hopes this article plays an influential role in introducing a new way for researchers in organization and management
Management and Ethics
No full textEthics as a regulatory mechanism for people ' s actions , play a very important role in organizational life .In this article ethical perspectives are presented in four categories :
I. Teleology , 2.Deontology , 3 . Relativism , and 4. Virtue ethics. Then author suggests an integrated Ethical system for organizations, that means a balanced system which takes into consideration all four perspectives: utilitarianism , respect for persons as human beings , Justice , and subordination of rules in society. At the end of the article continuance and maintance of ethical system is expressed
Sufism streamology in the Indian subcontinent and its peaceful coexistence with other religions
Full text linkThe Indian subcontinent is considered one of the five ancient civilizations in the world and the inheritor of a magnificent and diverse culture. India, as the largest country in this subcontinent, is considered the seventh largest country in the world. Due to its strategic importance, this region has always been favored by people from other parts of the world. Regarding the relationship of other nations, races and religions with the people of the Indian subcontinent, they were able to influence the life and culture of the region. One of the distinctive features of this region is the existence of different religions and religious sects, among which Hinduism, Buddhism and Islam are the most important religions of the region. The mentioned religions have many sects in the region, and one of the important Islamic sects is Sufism, which has established a positive interaction with other religions by becoming indigenous in the subcontinent and peacefully coexisting. In this article, after discussing the potentials and capacities of the subcontinent region, the author tries to investigate issues such as the importance of peaceful coexistence in Islam, interring in Islam and Sufism to the subcontinent, different sects of Sufism and its peaceful coexistence with other religions. In this regard, the author believes that Sufism was able to influence Hindu seekers through familiarity with philosophical works, the type of worldview and interaction with mystics and also through the peaceful coexistence emphasized by Islam. By taking advantage of good morals, decent behavior and the call to philanthropy derived from Islam, not only did they gain great influence among the common people, but beyond that, throughout history, they were able to attract the devotion of kings and gain a lot of power in the courts of some rulers of India
Pollen morphological analysis of the genus Lallemantia (Lamiaceae) of Iran
Full text linkLallemantia is a small genus of Lamiaceae with five herbaceous annual or biennial species. Some of these species are of medicinal value, while others have been used as the source of food. All five Lallemantia species occur in Iran. Although, there are many discussions about infra-generic variations in the genus, very scarce comprehensive studies are found about its taxonomy. Therefore, in the current study, pollen grain morphology was investigated using scanning electron microscopy. We used SPSS ver. 15 and PAST ver. 2.17 for multivariate statistical analyses of data. In total, we studied eleven qualitative and quantitative traits. Pollen equatorial and polar views were similar among the species and were prolate and circular, respectively. Pollen ornamentations differed as bireticulate (L. royleana and L. iberica), microreticulatm (L. peltata and L. Baldshuanica) and reticulate- faveolate (L. canescens). PCA-biplot showed some traits such as pori length/width ratio were important in identifications of species. The studied species created two groups in the WARD method tree of palynological data. L. royleana and L. baldshuanica were grouped together, and in the other group L. canescens and L. iberica placed nearly and L. peltata placed far from them. Our obtained results were similar to previous morphological study of the genus. The present study revealed taxonomic implication of the micromorphological study in the interspecific classification of the genus
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