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21.
Objectives: Skin‐derived precursors are recognized to be a potentially autologous and accessible source of neural precursor cells for drug screening or cell‐based treatments, in many neurological disorders. Thus, it is necessary to investigate appropriate methods for cryopreservation of such human skin‐derived precursors (hSKPs). The aim of this study was to evaluate different cryopreservation techniques for retention of hSKPs to discover an optimized protocol. Materials and methods: We cryopreserved hSKPs treated with 0%, 10%, 20%, 30% and 40% foetal bovine serum (FBS) and three concentrations of dimethylsulphoxide (DMSO) 5%, 10% and 15%, with two different storage periods in liquid nitrogen (2 days: short‐term storage; and 2 months: long‐term storage). Then, we assessed survival and proliferation levels of the cells after freeze–thaw processes, by viability measurement and colony‐forming assay. For detecting hSKPs, we used immunocytochemistry and RT‐PCR assessments. Results: Our findings indicated that hSKPs cryopreserved in 5% DMSO without FBS, had better survival and proliferation potentials compared to other working formulations. With various concentrations of cryoprotectants over different time periods, hSKPs retained their differentiation potentiality and were able to differentiate into neurons (NFM and βΙΙΙ tubulin‐positive), glial cells (GFAP‐positive) and smooth muscle cells (SMA‐positive). Conclusions: Results revealed that in only 5% DMSO, hSKPs could be cryopreserved for long‐term storage with considerable survival and proliferation levels, without losing multipotency.  相似文献   
22.
The stability of gemcitabine anticancer drug on the functionalized (8,0) zigzag carbon nanotube as a drug delivery vehicle is studied within the formalism of the density functional theory calculations to understand the role of the pyrrolidine functional group in binding the adsorbed molecule to the drug delivery system as well as improving water solubility. The binding energies, natural bond orbital calculations, and the quantum theory of atoms in molecules results are obtained to provide more evidences related to the intermolecular interaction between gemcitabine drug and the functionalized nanotube. The negative binding energy corresponds to favorable binding of gemcitabine drug to the functionalized nanotube and presence of the active sites available for hydrogen bond formation facilitates better drug binding to the nanotube sidewall. The results presented in this article indicate that pyrrolidine functionalized carbon nanotube seems to be a novel material for drug delivery applications.

Communicated by Heidar Moradnia  相似文献   

23.
Breast cancer (BC) is an important cause of female cancer-related death. It has recently been demonstrated that metabolic disorders including lipid metabolism are a hallmark of cancer cells. Lipin-1 is an enzyme that displays phosphatidate phosphatase activity and regulates the rate-limiting step in the pathway of triglycerides and phospholipids synthesis. The objective of this study was to evaluate lipin-1 expression, its prognostic significance, and its correlation with p53 tumor suppressor in patients with BC. In this study, 55 pairs of fresh samples of BC and adjacent noncancerous tissue were used to analyze lipin-1, using quantitative real-time polymerase chain reaction and immunohistochemistry (IHC) staining. The expression of other clinicopathological variables and p53 was also examined using IHC technique. The cell migration was studied in MCF-7 and MDA-MB231 cells following the inhibition of lipin-1 by propranolol. Our results show that the relative expression of lipin-1 messenger RNA was significantly higher in BC tissues compared with the adjacent normal tissue and its inhibition reduced cell migration in cancer cells. This upregulation was negatively correlated with histological grade of tumor and p53 status (p = .001 and p = .034) respectively and positively correlated with the tumor size (p = .006). Our results also seem to indicate that the high lipin-1 expression is related to a good prognosis in patients with BC. The expression of lipin-1 may be considered as a novel independent prognostic factor. The inhibition of lipin-1 may also have therapeutic significance for patients with BC. The correlation between lipin-1 and p53 confirms the role of p53 in the regulation of lipid metabolism in cancer cells.  相似文献   
24.
On many occasions, the effects of wind-induced waves and currents on flow and salinity fields in water bodies are evaluated separately. Some coupling mechanisms of the two phenomena, however, can have a significant impact on the flow and salinity conditions, in particular in sensitive aquatic ecosystems. This article attempts to quantify the wave contributions to the flow and salinity regimes in Lake Urmia, Iran. The salinity conditions in the lake have become an environmentally important subject, partly because this shallow hypersaline aquatic ecosystem is considered to be one of the largest natural habitats of a unique multicellular organism, Artemia urmiana. This brine shrimp is the major food source for many of the protected and rare shorebirds that visit the lake and can grow and survive in only certain ranges of salinity. The lake has also experienced considerable man-made changes during the past three decades. Previous studies that have modeled the flow and salinity regimes in the lake have overlooked the wave-coupling effects, and some have concluded that major remedial actions are necessary to restore the lake ecosystem. The wave-coupling effects were found to have significant impacts on the spatiotemporal variations of flow and salinity in the lake. Wave actions were intensifying vertical stratification, considerably influencing the flow and salinity regimes. It was found that improvements in the lake salinity conditions provided by the wave actions were comparable to potential improvements that expensive mitigation scenarios may offer. The relative magnitude of the wave coupling was found to be the highest in shallow/large water bodies, and it increased as the wave height and the initial salinity increased, suggesting that these wave-coupling effects are substantial, especially in large, shallow, hypersaline lakes.  相似文献   
25.
MicroRNAs (miRNAs) have been implicated in the orchestration of diverse cellular processes including differentiation, proliferation, and apoptosis and are believed to play pivotal roles as oncogenes and tumor suppressors. miR-122, a liver specific miRNA, is significantly down-regulated in most hepatocellular carcinomas (HCCs) but its role in tumorigenesis remains poorly understood. Here we identify AKT3 as a novel and direct target of miR-122. Restoration of miR-122 expression in HCC cell lines decreases AKT3 levels, inhibits cell migration and proliferation, and induces apoptosis. These anti-tumor phenotypes can be rescued by reconstitution of AKT3 expression indicating the essential role of AKT3 in miR-122 mediated HCC transformation. In vivo, restoration of miR-122 completely inhibited xenograft growth of HCC tumor in mice. Our data strongly suggest that miR-122 is a tumor suppressor that targets AKT3 to regulate tumorigenesis in HCCs and a potential therapeutic candidate for liver cancer.  相似文献   
26.
27.
Journal of Plant Growth Regulation - Lepidium sativum L. is an annual herb with various medicinal and industrial applications. In addition, the elicitation process is considered as a highly...  相似文献   
28.
Bottlenose dolphins (Tursiops truncatus) use the frequency contour of whistles produced by conspecifics for individual recognition. Here we tested a bottlenose dolphin’s (Tursiops truncatus) ability to recognize frequency modulated whistle-like sounds using a three alternative matching-to-sample paradigm. The dolphin was first trained to select a specific object (object A) in response to a specific sound (sound A) for a total of three object-sound associations. The sounds were then transformed by amplitude, duration, or frequency transposition while still preserving the frequency contour of each sound. For comparison purposes, 30 human participants completed an identical task with the same sounds, objects, and training procedure. The dolphin’s ability to correctly match objects to sounds was robust to changes in amplitude with only a minor decrement in performance for short durations. The dolphin failed to recognize sounds that were frequency transposed by plus or minus ½ octaves. Human participants demonstrated robust recognition with all acoustic transformations. The results indicate that this dolphin’s acoustic recognition of whistle-like sounds was constrained by absolute pitch. Unlike human speech, which varies considerably in average frequency, signature whistles are relatively stable in frequency, which may have selected for a whistle recognition system invariant to frequency transposition.  相似文献   
29.
A simple, clean and environmentally benign route to the synthesis of 2-amino-4H-chromenes is described using Preyssler type heteropolyacid, H(14)[NaP(5)W(30)O(110)], as a green and reusable catalyst in water. The products were obtained in very good yields.  相似文献   
30.
Cobalt(III) complexes with potentially tetradentate salophen (H2salophen = N,N′-bis(salicylidene)-1,2-phenylenediamine) as equatorial ligand and with different axial amine ligands (NH3, cyclohexylamine, aniline, 4-picoline and pyridine) were synthesized and characterized by IR, 1H NMR, elemental analysis. Electronic spectra and electrochemical properties of the complexes were studied in DMF solutions. The lowest energy transitions, which occur between 464.8 and 477 nm, are attributed mainly to the intraligand charge transfer, confirmed by Zindo/S electronic structure calculations. The reduction potentials of Co(III)/Co(II) are more affected than those of Co(II)/Co(I) by the axial amine ligands. The crystal structure of the [CoIII(salophen)(4- picoline)2]ClO4 · CH2Cl2 was determined, indicating that the cobalt(III) center is six coordinated surrounded by the tetradentate salophen ligand and two 4-picoline ligands. The crystal packing of the complex shows a layered structure, in which the perchlorate counter ions and also the lattice solvent molecules are intercalated between the bc planes of the complex cations.  相似文献   
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