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271.
Anjum Qureshi Dolly Singh N.L. Singh S. Ataoglu Arif N. Gulluoglu Ambuj Tripathi D.K. Avasthi 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2009,267(20):3456-3460
Changes in the optical, structural, dielectric properties and surface morphology of a polypropylene/TiO2 composite due to swift heavy ion irradiation were studied by means of UV–visible spectroscopy, X-ray diffraction, impedance gain phase analyzer and atomic force microscopy. Samples were irradiated with 140 MeV Ag11+ ions at fluences of 1 × 1011 and 5 × 1012 ions/cm2. UV–visible absorption analysis reveals a decrease in optical direct band gap from 2.62 to 2.42 eV after a fluence of 5 × 1012 ions/cm2. X-ray diffractograms show an increase in crystallinity of the composite due to irradiation. The dielectric constants obey the Universal law given by ε α f n−1, where n varies from 0.38 to 0.91. The dielectric constant and loss are observed to change significantly due to irradiation. Cole–cole diagrams have shown the frequency dependence of the complex impedance at different fluences. The average surface roughness of the composite decreases upon irradiation. 相似文献
272.
May Nasser Bin-Jumah Muhammad Shahid Nadeem Sadaf Jamal Gilani Fahad A. Al-Abbasi Inam Ullah Sami I. Alzarea Mohammed M. Ghoneim Sultan Alshehri Aziz Uddin Bibi Nazia Murtaza Imran Kazmi 《International journal of molecular sciences》2022,23(3)
Aging is a complex process indicated by low energy levels, declined physiological activity, stress induced loss of homeostasis leading to the risk of diseases and mortality. Recent developments in medical sciences and an increased availability of nutritional requirements has significantly increased the average human lifespan worldwide. Several environmental and physiological factors contribute to the aging process. However, about 40% human life expectancy is inherited among generations, many lifespan associated genes, genetic mechanisms and pathways have been demonstrated during last decades. In the present review, we have evaluated many human genes and their non-human orthologs established for their role in the regulation of lifespan. The study has included more than fifty genes reported in the literature for their contributions to the longevity of life. Intact genomic DNA is essential for the life activities at the level of cell, tissue, and organ. Nucleic acids are vulnerable to oxidative stress, chemotherapies, and exposure to radiations. Efficient DNA repair mechanisms are essential for the maintenance of genomic integrity, damaged DNA is not replicated and transferred to next generations rather the presence of deleterious DNA initiates signaling cascades leading to the cell cycle arrest or apoptosis. DNA modifications, DNA methylation, histone methylation, histone acetylation and DNA damage can eventually lead towards apoptosis. The importance of calorie restriction therapy in the extension of lifespan has also been discussed. The role of pathways involved in the regulation of lifespan such as DAF-16/FOXO (forkhead box protein O1), TOR and JNK pathways has also been particularized. The study provides an updated account of genetic factors associated with the extended lifespan and their interactive contributory role with cellular pathways. 相似文献
273.
Abida Bano Sofia Rashid Mushtaq Ahmad Ghulam R. Bhatti Ghulam Yaseen Farida Anjum Sidra N. Ahmed Muhammad Zafar Maliha Asma Shazia Sultana Muhammad Adeel Fethi A. Ozdemir Omer Kilic 《Microscopy research and technique》2020,83(6):579-588
The study was conducted to highlight a detailed account of morphology of pollen chosen species of Lamiaceae through scanning electron microscopy, and the anatomical characteristics of leaf epidermis of seven species using simple light microscopy. In results, Anisomeles indica and Otostegia aucheri belong to subfamily Lamioideae because it has tricolpate pollen while the rest eight species belong to subfamily Nepetoideae (hexacolpate pollen). The exine sculpturing of pollen of studied species was found to be reticulate. In the family Lamiaceae, four kinds of stomata were found anomocytic, anisocytic, diacytic, and actinocytic, respectively. The cell wall patterns of epidermal cells were irregular or polygonal with straight or undulate walls. It was noted that the variety of the epidermal trichomes seems of taxonomically important for the identification of species of Lamiaceae. Both nonglandular and glandular trichomes were analyzed. The nonglandular trichomes were characterized with long, thin, and pointed apical unicellular cells. The nonglandular trichomes were A‐shaped in Thymus linearis. In Perovskia abrotanoides, stellate glandular trichomes were observed whereas in A. indica and Mentha royleana both glandular and nonglandular trichomes were found. In A. indica, the nonglandular trichomes were sessile and peltate in M. royleana. For the first time in this study, pollen and foliar micromorphological features of selected species of this area are carried out. These taxonomic characters were found to be important in discrimination of species from each other. In future, the detailed study with comprehensive morphology coupled with other important characters is required for delimitation of taxa at various levels. 相似文献
274.
Nazia Yaqoob Ijaz Ahmed Bhatti Farooq Anwar Muhammad Rafique Asi 《European Journal of Lipid Science and Technology》2010,112(4):488-495
The characteristics of oils extracted from gamma‐irradiated sunflower (Halianthus annuus) and maize (Zea mays) seeds at absorbed doses of 2, 4, 6, 8, and 10 kGy were investigated. Gamma irradiation did not affect the lipid, protein, fiber, and ash contents of neither sunflower nor maize seeds significantly (p>0.05). No significant changes were observed for the values of refractive index and density between the control and irradiated sunflower and maize oils. Peroxide value, acid value, para‐anisidine value, and conjugated dienes and trienes contents increased, while iodine values decreased in the irradiated oils as compared to those of control oils (p<0.05). A small decrease in the contents of α‐, γ‐, and δ‐tocopherols of both sunflower and maize oils was noted by radiation treatment up to 6 kGy, however, the decline was more pronounced at higher dosages. The effects of irradiation on the fatty acid composition of sunflower oil showed a significant (p<0.05) change in the amounts of stearic, oleic, and linoleic acids, while the concentration of palmitic acid was unaffected even at 10 kGy. Similar trends in the fatty acid profile were found for both the sunflower and maize oil. 相似文献
275.
A hallmark of G-protein-coupled receptors (GPCRs) is their ability to recognize and respond to chemically diverse ligands. Lysophospholipids constitute a relatively recent addition to these ligands and carry out their biological functions by activating G-proteins coupled to a large family of cell-surface receptors. This review aims to highlight salient features of cell signaling by one class of these receptors, known as lysophosphatidic acid (LPA) receptors, in the context of phosphatidylinositol 3-kinase (PI3K)–AKT pathway activation. LPA moieties efficiently activate AKT phosphorylation and activation in a multitude of cell types. The interplay between LPA, its receptors, the associated Gαi/o subunits, PI3K and AKT contributes to the regulation of cell survival, migration, proliferation and confers chemotherapy-resistance in certain cancers. However, detailed information on the regulation of PI3K–AKT signals induced by LPA receptors is missing from the literature. Here, some urgent issues for investigation are highlighted. 相似文献
276.
Appraisal of the tire derived rubber (TDR) medium for wastewater treatment under aerobic and anaerobic conditions 下载免费PDF全文
277.
Talat Zeeshan Safia Anjum Salma Waseem Lubna Mustufa 《Ceramics International》2018,44(15):17709-17715
The simple and cost-effective powder metallurgy method has been employed to prepare a series of copper substituted cobalt chromium ferrites CuxCo1-xCr0.5Fe2O4 (x?=?0, 0.2, 0.4, 0.6, 0.8, 1.0). The calcination of the samples has been carried out at 1100?°C for 24?h. X-Ray Diffractometer (XRD) and Fourier transform infrared spectroscopy (FTIR) measurement proves the formation of cubic spinel ferrites. Vibrating Sample Magnetometer (VSM)) analysis revealed that the substitution of copper in the Co-Cr ferrites leads to reduce the magnetic moment that in turns decrease the saturation magnetization and coercivity. The Ultra violet visible spectroscopy (UV–VIS) showed that the band gap energy increases with copper substitution which is due to reduction in crystallite size. The results indicate that the replacement of copper with the cobalt-chromium ferries strongly influences the crystal structure, microstructure, magnetic parameters and band gap energy. 相似文献
278.
Kari Kopra Salla Valtonen Randa Mahran Jonas N. Kapp Nazia Hassan William Gillette Bryce Dennis Lianbo Li Kenneth D. Westover Andreas Plückthun Harri Hrm 《International journal of molecular sciences》2022,23(13)
Thermal unfolding methods are commonly used as a predictive technique by tracking the protein’s physical properties. Inherent protein thermal stability and unfolding profiles of biotherapeutics can help to screen or study potential drugs and to find stabilizing or destabilizing conditions. Differential scanning calorimetry (DSC) is a ‘Gold Standard’ for thermal stability assays (TSA), but there are also a multitude of other methodologies, such as differential scanning fluorimetry (DSF). The use of an external probe increases the assay throughput, making it more suitable for screening studies, but the current methodologies suffer from relatively low sensitivity. While DSF is an effective tool for screening, interpretation and comparison of the results is often complicated. To overcome these challenges, we compared three thermal stability probes in small GTPase stability studies: SYPRO Orange, 8-anilino-1-naphthalenesulfonic acid (ANS), and the Protein-Probe. We studied mainly KRAS, as a proof of principle to obtain biochemical knowledge through TSA profiles. We showed that the Protein-Probe can work at lower concentration than the other dyes, and its sensitivity enables effective studies with non-covalent and covalent drugs at the nanomolar level. Using examples, we describe the parameters, which must be taken into account when characterizing the effect of drug candidates, of both small molecules and Designed Ankyrin Repeat Proteins. 相似文献
279.
Tanzila Saba Sana Ullah Khan Naveed Islam Naveed Abbas Amjad Rehman Nadeem Javaid Adeel Anjum 《Microscopy research and technique》2019,82(6):775-785
The advancement of computer‐ and internet‐based technologies has transformed the nature of services in healthcare by using mobile devices in conjunction with cloud computing. The classical phenomenon of patient–doctor diagnostics is extended to a more robust advanced concept of E‐health, where remote online/offline treatment and diagnostics can be performed. In this article, we propose a framework which incorporates a cloud‐based decision support system for the detection and classification of malignant cells in breast cancer, while using breast cytology images. In the proposed approach, shape‐based features are used for the detection of tumor cells. Furthermore, these features are used for the classification of cells into malignant and benign categories using Naive Bayesian and Artificial Neural Network. Moreover, an important phase addressed in the proposed framework is the grading of the affected cells, which could help in grade level necessary medical procedures for patients during the diagnostic process. For demonstrating the e effectiveness of the proposed approach, experiments are performed on real data sets comprising of patients data, which has been collected from the pathology department of Lady Reading Hospital of Pakistan. Moreover, a cross‐validation technique has been performed for the evaluation of the classification accuracy, which shows performance accuracy of 98% as compared to physical methods used by a pathologist for the detection and classification of the malignant cell. Experimental results show that the proposed approach has significantly improved the detection and classification of the malignant cells in breast cytology images. 相似文献
280.
Islam Adeela Anjum Tayaba Khan Nazar 《International Journal on Document Analysis and Recognition》2023,26(3):335-346
International Journal on Document Analysis and Recognition (IJDAR) - Extraction of text lines from handwritten document images is important for downstream text recognition tasks. It is challenging... 相似文献