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Sample records for addition cell morphology

  1. Acetate Salts as Nonhalogen Additives To Improve Perovskite Film Morphology for High-Efficiency Solar Cells.

    PubMed

    Wu, Qiliang; Zhou, Pengcheng; Zhou, Weiran; Wei, Xiangfeng; Chen, Tao; Yang, Shangfeng

    2016-06-22

    A two-step method has been popularly adopted to fabricate a perovskite film of planar heterojunction organo-lead halide perovskite solar cells (PSCs). However, this method often generates uncontrollable film morphology with poor coverage. Herein, we report a facile method to improve perovskite film morphology by incorporating a small amount of acetate (CH3COO(-), Ac(-)) salts (NH4Ac, NaAc) as nonhalogen additives in CH3NH3I solution used for immersing PbI2 film, resulting in improved CH3NH3PbI3 film morphology. Under the optimized NH4Ac additive concentration of 10 wt %, the best power conversion efficiency (PCE) reaches 17.02%, which is enhanced by ∼23.2% relative to that of the pristine device without additive, whereas the NaAc additive does not lead to an efficiency enhancement despite the improvement of the CH3NH3PbI3 film morphology. SEM study reveals that NH4Ac and NaAc additives can both effectively improve perovskite film morphology by increasing the surface coverage via diminishing pinholes. The improvement on CH3NH3PbI3 film morphology is beneficial for increasing the optical absorption of perovskite film and improving the interfacial contact at the perovskite/spiro-OMeTAD interface, leading to the increase of short-circuit current and consequently efficiency enhancement of the PSC device for NH4Ac additive only.

  2. Morphology-Controlled High-Efficiency Small Molecule Organic Solar Cells without Additive Solvent Treatment

    PubMed Central

    Kim, Il Ku; Jo, Jun Hyung; Yun, Jung-Ho

    2016-01-01

    This paper focuses on nano-morphology-controlled small-molecule organic solar cells without solvent treatment for high power-conversion efficiencies (PCEs). The maximum high PCE reaches up to 7.22% with a bulk-heterojunction (BHJ) thickness of 320 nm. This high efficiency was obtained by eliminating solvent additives such as 1,8-diiodooctane (DIO) to find an alternative way to control the domain sizes in the BHJ layer. Furthermore, the generalized transfer matrix method (GTMM) analysis has been applied to confirm the effects of applying a different thickness of BHJs for organic solar cells from 100 to 320 nm, respectively. Finally, the study showed an alternative way to achieve high PCE organic solar cells without additive solvent treatments to control the morphology of the bulk-heterojunction.

  3. Low-boiling-point solvent additives can also enable morphological control in polymer solar cells

    SciTech Connect

    Mahadevapuram, Rakesh C.; Carr, John A.; Chen, Yuqing; Bose, Sayantan; Nalwa, Kanwar S.; Petrich, Jacob W.; Chaudhary, Sumit

    2013-11-02

    Processing organic photovoltaic (OPV) blend solutions with high-boiling-point solvent additives has recently been used for morphological control in bulk-heterojunction OPV cells. Here we show that even low-boiling-point solvents can be effective additives. When P3HT:PCBM OPV cells were processed with a low-boiling-point solvent tetrahydrafuran as an additive in parent solvent o-dichlorobenzene, charge extraction increased leading to fill factors as high as 69.5%, without low work-function cathodes, electrode buffer layers or thermal treatment. This was attributed to PCBM demixing from P3HT domains and better vertical phase separation, as indicated by photoluminescence lifetimes, hole mobilities, and shunt leakage currents. Dependence on solvent parameters and applicability beyond P3HT system was also investigated. (C) 2013 Elsevier B.V. All rights reserved.

  4. Tuning perovskite morphology by polymer additive for high efficiency solar cell.

    PubMed

    Chang, Chun-Yu; Chu, Cheng-Ya; Huang, Yu-Ching; Huang, Chien-Wen; Chang, Shuang-Yuan; Chen, Chien-An; Chao, Chi-Yang; Su, Wei-Fang

    2015-03-04

    Solution processable planar heterojunction perovskite solar cell is a very promising new technology for low cost renewable energy. One of the most common cell structures is FTO/TiO2/CH3NH3PbI3-xClx/spiro-OMeTAD/Au. The main issues of this type of solar cell are the poor coverage and morphology control of the perovskite CH3NH3PbI3-xClx film on TiO2. For the first time, we demonstrate that the problems can be easily resolved by using a polymer additive in perovskite precursor solution during the film formation process. A 25% increase in power conversion efficiency at a value of 13.2% is achieved by adding 1 wt % of poly(ethylene glycol) in the perovskite layer using a 150 °C processed TiO2 nanoparticle layer. The morphology of this new perovskite was carefully studied by SEM, XRD, and AFM. The results reveal that the additive controls the size and aggregation of perovskite crystals and helps the formation of smooth film over TiO2 completely. Thus, the Voc and Jsc are greatly increased for a high efficiency solar cell. The amount of additive is optimized at 1 wt % due to its insulating characteristics. This research provides a facile way to fabricate a high efficiency perovskite solar cell by the low temperature solution process (<150 °C), which has the advancement of conserving energy over the traditional high temperature sintering TiO2 compact layer device.

  5. Selective Morphology Control of Bulk Heterojunction in Polymer Solar Cells Using Binary Processing Additives.

    PubMed

    Jung, Yen-Sook; Yeo, Jun-Seok; Kim, Nam-Koo; Lee, Sehyun; Kim, Dong-Yu

    2016-11-09

    We report the effect of binary additives on the fabrication of polymer solar cells (PSCs) based on a bulk heterojunction (BHJ) system. The combination of 1,8-diiodooctane (DIO), a high-boiling and selective solvent, for fullerene derivatives and poly(dimethylsiloxane) (PDMS) precursor, a nonvolatile insulating additive, affords complementary functions on the effective modulation of BHJ morphology. It was found that DIO and PDMS precursor each play different roles in the control of BHJ morphology, and thus, the power conversion efficiency (PCE) can be further enhanced to 7.6% by improving the fill factor (FF) from 6.8% compared to that achieved using a conventional device employing only a DIO additive. In the BHJ of the active layer, DIO suppressed the large phase separation of PBDTTT-CF and PC71BM while allowing the formation of continuous polymer networks in the donor polymer through phase separation of the PDMS precursor and BHJ components. The appropriate amount of PDMS precursor does not disturb charge transport in the BHJ despite having insulating properties. In addition, the dependence of photovoltaic parameters on different light intensities reveals that the charge recombination in the device with DIO and PDMS precursor decreases compared to that achieved using the device with only DIO.

  6. Revealing the Effect of Additives with Different Solubility on the Morphology and the Donor Crystalline Structures of Organic Solar Cells.

    PubMed

    Zhao, Jiao; Zhao, Suling; Xu, Zheng; Qiao, Bo; Huang, Di; Zhao, Ling; Li, Yang; Zhu, Youqin; Wang, Peng

    2016-07-20

    The impact of two kinds of additives, such as 1,8-octanedithiol (ODT), 1,8-diiodooctane (DIO), diphenylether (DPE), and 1-chloronaphthalene (CN), on the performance of poly[(5,6-difluoro-2,1,3-benzothiadiazol-4,7-diyl)-alt-(3,3‴-di(2-octyldodecyl)2,2';5',2″;5″,2‴-quaterthiophen-5,5‴-diyl)] (PffBT4T-2OD):[6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) based polymer solar cell are investigated. The polymer solar cells (PSCs) of PffBT4T-2OD:PC71BM by using CN show a more improved PCE of 10.23%. The solubility difference of PffBT4T-2OD in DIO and CN creates the fine transformation in phase separation and favorable nanoscale morphology. Grazing incidence X-ray diffraction (GIXRD) data clearly shows molecular stacking and orientation of the active layer. Interestingly, DIO and CN have different functions on the effect of the molecular orientation. These interesting studies provide important guidance to optimize and control complicated molecular orientations and nanoscale morphology of PffBT4T-2OD based thick films for the application in PSCs.

  7. Origin of effects of additive solvent on film-morphology in solution-processed nonfullerene solar cells.

    PubMed

    Chen, Yuxia; Zhang, Xin; Zhan, Chuanlang; Yao, Jiannian

    2015-04-01

    In this paper, we report an efficient nonfullerene solar cell based on small molecules of p-DTS(FBTTh2)2 and bis-PDI-T. Characterization data indicate that the nature of the acceptor aggregate is a key factor that affects the photocurrent. There is a good relationship between the short-circuit current density (J(SC)) and the phase size of the acceptor-rich domains. The phase size of the acceptor-rich domains is tuned by both the additive types and additive content. As the kind of additive goes from 1-chloronaphthalene (CN) to 1,8-octanedithiol (ODT) and 1,8-diiodooctane (DIO), by this order the solubility of the acceptor in the additive is down, the phase size significantly decreases from over 400 nm down to 30 nm. Also, the acceptor's domain size decreases from 80 to 30 nm as the DIO content ([DIO]) is down from 1% to 0.15%. Following this trend, less DIO remains in the wet film as residue after the host chloroform evaporates, and thus less acceptor can be dissolved in the residue DIO. This decreasing of DIO content acts on the film-morphology similarly as the additive changes down to the one having a lower solubility. Accordingly, our results indicate that it is the dissolved amount of the organic component in the residue additive solvent of the wet film that plays a role in turning the phase size. The efficiency from this small molecule system is significantly raised from 0.02% up to 3.7% by selecting the additive type and fine-tuning the additive content.

  8. Photovoltaic properties and morphology of organic solar cells based on liquid-crystal semiconducting polymer with additive

    SciTech Connect

    Suzuki, Atsushi; Zushi, Masahito; Suzuki, Hisato; Ogahara, Shinichi; Akiyama, Tsuyoshi; Oku, Takeo

    2014-02-20

    Bulk heterojunction organic solar cell based on liquid crystal semiconducting polymers of poly[9,9-dioctylfluorene-co-bithiophene] (F8T2) as p-type semiconductors and fullerenes (C{sub 60}) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) as electron donor and acceptor has been fabricated and characterized for improving photovoltaic and optical properties. The photovoltaic performance including current voltage curves in the dark and illumination of the F8T2/C{sub 60} conventional and inverted bulk heterojunction solar cells were investigated. Relationship between the photovoltaic properties and morphological behavior was focused on tuning for optimization of photo-voltaic performance under annealing condition near glass transition temperature. Additive-effect of diiodooctane (DIO) and poly(3-hexylthiophene-2,5-diyl) (P3HT) on the photovoltaic performance and optical properties was investigated. Mechanism of the photovoltaic properties of the conventional and inverted solar cells will be discussed by the experimental results.

  9. Multitask Imidazolium Salt Additives for Innovative Poly(l-lactide) Biomaterials: Morphology Control, Candida spp. Biofilm Inhibition, Human Mesenchymal Stem Cell Biocompatibility, and Skin Tolerance.

    PubMed

    Schrekker, Clarissa M L; Sokolovicz, Yuri C A; Raucci, Maria G; Selukar, Balaji S; Klitzke, Joice S; Lopes, William; Leal, Claudio A M; de Souza, Igor O P; Galland, Griselda B; Dos Santos, João Henrique Z; Mauler, Raquel S; Kol, Moshe; Dagorne, Samuel; Ambrosio, Luigi; Teixeira, Mário L; Morais, Jonder; Landers, Richard; Fuentefria, Alexandre M; Schrekker, Henri S

    2016-08-24

    Candida species have great ability to colonize and form biofilms on medical devices, causing infections in human hosts. In this study, poly(l-lactide) films with different imidazolium salt (1-n-hexadecyl-3-methylimidazolium chloride (C16MImCl) and 1-n-hexadecyl-3-methylimidazolium methanesulfonate (C16MImMeS)) contents were prepared, using the solvent casting process. Poly(l-lactide)-imidazolium salt films were obtained with different surface morphologies (spherical and directional), and the presence of the imidazolium salt in the surface was confirmed. These films with different concentrations of the imidazolium salts C16MImCl and C16MImMeS presented antibiofilm activity against isolates of Candida tropicalis, Candida parapsilosis, and Candida albicans. The minor antibiofilm concentration assay enabled one to determine that an increasing imidazolium salt content promoted, in general, an increase in the inhibition percentage of biofilm formation. Scanning electron microscopy micrographs confirmed the effective prevention of biofilm formation on the imidazolium salt containing biomaterials. Lower concentrations of the imidazolium salts showed no cytotoxicity, and the poly(l-lactide)-imidazolium salt films presented good cell adhesion and proliferation percentages with human mesenchymal stem cells. Furthermore, no acute microscopic lesions were identified in the histopathological evaluation after contact between the films and pig ear skin. In combination with the good morphological, physicochemical, and mechanical properties, these poly(l-lactide)-based materials with imidazolium salt additives can be considered as promising biomaterials for use in the manufacturing of medical devices.

  10. Influence of the addition of β-TCP on the morphology, thermal properties and cell viability of poly (lactic acid) fibers obtained by electrospinning.

    PubMed

    Siqueira, L; Passador, F R; Costa, M M; Lobo, A O; Sousa, E

    2015-01-01

    Electrospinning is a simple and low-cost way to fabricate fibers. Among the various polymers used in electrospinning process, the poly (lactic acid) (PLA) stands out due to its excellent biodegradability and biocompatibility. Calcium phosphate ceramics has been recognized as an attractive biomaterial because their chemical composition is similar to the mineral component of the hard tissue in the body. Furthermore, they are bioactive and osteoinductive and some are even quite biodegradable. The beta-tricalcium phosphate (β-TCP) particles were synthesized by solid state reaction. Different contents of β-TCP particles were incorporated in polymer matrices to form fibers of PLA/β-TCP composites by electrospinning aiming a possible application as a scaffold for tissue engineering. The fibers were characterized by scanning electron microscopy (SEM), infrared (FTIR), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The average diameter of the fibers varied in the range of 260-519.6 ± 50 nm. The presence of β-TCP particles promoted changes on thermal properties of the fibers. The composite with 8 wt-% of β-TCP showed a low degree of crystallinity and can be used for application in tissue engineering. The cell viability was analyzed by reduction of the methyl tetrazolium salt by the pyruvate dehydrogenase enzymatic complex present in the matrix of mitochondria (MTT test). All PLA fiber groups, with different contents of β-TCP, showed cytocompatibility ability with non-cytotoxicity effect and bioactive properties using SBF assay.

  11. Plastic solar cell interface and morphological characterization

    NASA Astrophysics Data System (ADS)

    Guralnick, Brett W.

    Plastic solar cell research has become an intense field of study considering these devices may be lightweight, flexible and reduce the cost of photovoltaic devices. The active layer of plastic solar cells are a combination of two organic components which blend to form an internal morphology. Due to the poor electrical transport properties of the organic components it is important to understand how the morphology forms in order to engineer these materials for increased efficiency. The focus of this thesis is a detailed study of the interfaces between the plastic solar cell layers and the morphology of the active layer. The system studied in detail is a blend of P3HT and PCBM that acts as the primary absorber, which is the electron donor, and the electron acceptor, respectively. The key morphological findings are, while thermal annealing increases the crystallinity parallel to the substrate, the morphology is largely unchanged following annealing. The deposition and mixing conditions of the bulk heterojunction from solution control the starting morphology. The spin coating speed, concentration, solvent type, and solution mixing time are all critical variables in the formation of the bulk heterojunction. In addition, including the terminals or inorganic layers in the analysis is critical because the inorganic surface properties influence the morphology. Charge transfer in the device occurs at the material interfaces, and a highly resistive transparent conducting oxide layer limits device performance. It was discovered that the electron blocking layer between the transparent conducting oxide and the bulk heterojunction is compromised following annealing. The electron acceptor material can diffuse into this layer, a location which does not benefit device performance. Additionally, the back contact deposition is important since the organic material can be damaged by the thermal evaporation of Aluminum, typically used for plastic solar cells. Depositing a thin thermal and

  12. Influence of urea additives on micellar morphology/protein conformation.

    PubMed

    Gull, Nuzhat; Kumar, Sanjeev; Ahmad, Basir; Khan, Rizwan Hassan; Kabir-ud-Din

    2006-08-01

    The present study highlights the fact that the effect of additives (urea, monomethylurea, thiourea) on the supramolecular assemblies and proteins is strikingly similar. To investigate the effect, a viscometeric study on sphere-to-rod transition (s-->r) was undertaken in a system (3.5% tetradecyltrimethylammonium bromide+0.05 M NaBr + 1-pentanol [P.M. Lindemuth, G.L. Bertand, J. Phys. Chem. 97 (1993) 7769]) in the presence and absence of the said additives. [1-pentanol] needed for s-->r (i.e. [1-pentanol]s-->r) was determined from the relative viscosity versus [1-pentanol] profiles. It was observed that the additives preponed as well as postponed s-->r depending upon their nature and concentrations. These effects are explained in terms of increased polarity of the medium and the adsorption ability of urea/monomethylurea on the charged surfactant monomers of the micelle. In case of thiourea, postponement of s-->r was observed throughout which is attributed to its structure. To derive an analogy between micelles and proteins the additive-induced conformational changes of the protein, bovine serum albumin (BSA) was taken to monitor secondary structural changes and tryptophanyl fluorescence. A marked increase in secondary structure (far-UVCD) and increased tryptophanyl fluorescence with a marked blue shift in lambdamax was observed in presence of low concentrations of urea or alkylurea. This indicates that a more compact environment is created in presence of these additives, if added judiciously. Addition of thiourea to BSA caused a marked quenching without any significant change in lambdamax. The large decrease in tryptophanyl emission in presence of low thiourea concentrations seems to be specific and related to thiourea structure as no corresponding changes were observed in urea/alkylurea. All these effects pertaining to protein behavior fall in line with that of morphological observations on the present as well as surfactant systems studied earlier [S. Kumar, N

  13. Recent Advances in Morphological Cell Image Analysis

    PubMed Central

    Chen, Shengyong; Zhao, Mingzhu; Wu, Guang; Yao, Chunyan; Zhang, Jianwei

    2012-01-01

    This paper summarizes the recent advances in image processing methods for morphological cell analysis. The topic of morphological analysis has received much attention with the increasing demands in both bioinformatics and biomedical applications. Among many factors that affect the diagnosis of a disease, morphological cell analysis and statistics have made great contributions to results and effects for a doctor. Morphological cell analysis finds the cellar shape, cellar regularity, classification, statistics, diagnosis, and so forth. In the last 20 years, about 1000 publications have reported the use of morphological cell analysis in biomedical research. Relevant solutions encompass a rather wide application area, such as cell clumps segmentation, morphological characteristics extraction, 3D reconstruction, abnormal cells identification, and statistical analysis. These reports are summarized in this paper to enable easy referral to suitable methods for practical solutions. Representative contributions and future research trends are also addressed. PMID:22272215

  14. Effect of crystals and fibrous network polymer additives on cellular morphology of microcellular foams

    NASA Astrophysics Data System (ADS)

    Miyamoto, Ryoma; Utano, Tatsumi; Yasuhara, Shunya; Ishihara, Shota; Ohshima, Masahiro

    2015-05-01

    In this study, the core-back foam injection molding was used for preparing microcelluar polypropylene (PP) foam with either a 1,3:2,4 bis-O-(4-methylbenzylidene)-D-sorbitol gelling agent (Gel-all MD) or a fibros network polymer additive (Metablen 3000). Both agent and addiive could effectively control the celluar morphology in foams but somehow different ways. In course of cooling the polymer with Gel-all MD in the mold caity, the agent enhanced the crystal nucleation and resulted in the large number of small crystals. The crystals acted as effective bubble nucleation agent in foaming process. Thus, the agent reduced the cell size and increased the cell density, drastically. Furthermore, the small crystals provided an inhomogenuity to the expanding cell wall and produced the high open cell content with nano-scale fibril structure. Gell-all as well as Metablene 3000 formed a gel-like fibrous network in melt. The network increased the elongational viscosity and tended to prevent the cell wall from breaking up. The foaming temperature window was widened by the presence of the network. Especially, the temperature window where the macro-fibrous structure was formed was expanded to the higher temperature. The effects of crystal nucleating agent and PTFE on crystals' size and number, viscoelsticity, rheological propreties of PP and cellular morphology were compared and thorougly investigated.

  15. Mitochondrial dynamics and morphology in beta-cells.

    PubMed

    Stiles, Linsey; Shirihai, Orian S

    2012-12-01

    Mitochondrial dynamics contribute to the regulation of mitochondrial shape as well as various mitochondrial functions and quality control. This is of particular interest in the beta-cell because of the key role mitochondria play in the regulation of beta-cell insulin secretion function. Moreover, mitochondrial dysfunction has been suggested to contribute to the development of Type 2 Diabetes. Genetic tools that shift the balance of mitochondrial fusion and fission result in alterations to beta-cell function and viability. Additionally, conditions that induce beta-cell dysfunction, such as exposure to a high nutrient environment, disrupt mitochondrial morphology and dynamics. While it has been shown that mitochondria display a fragmented morphology in islets of diabetic patients and animal models, the mechanism behind this is currently unknown. Here, we review the current literature on mitochondrial morphology and dynamics in the beta-cell as well as some of the unanswered question in this field.

  16. Morphological properties of mouse retinal ganglion cells.

    PubMed

    Coombs, J; van der List, D; Wang, G-Y; Chalupa, L M

    2006-06-19

    The mouse retina offers an increasingly valuable model for vision research given the possibilities for genetic manipulation. Here we assess how the structural properties of mouse retinal ganglion cells relate to the stratification pattern of the dendrites of these neurons within the inner plexiform layer. For this purpose, we used 14 morphological measures to classify mouse retinal ganglion cells parametrically into different clusters. Retinal ganglion cells were labeled in one of three ways: Lucifer Yellow injection, 'DiOlistics' or transgenic expression of yellow fluorescent protein. The resulting analysis of 182 cells revealed 10 clusters of monostratified cells, with dendrites confined to either On or Off sublaminae of the inner plexiform layer, and four clusters of bistratified cells, dendrites spanning the On and Off sublaminae. We also sought to establish how these parametrically identified retinal ganglion cell clusters relate to cell types identified previously on the basis of immunocytochemical staining and the expression of yellow fluorescent protein. Cells labeled with an antibody against melanopsin were found to be located within a single cluster, while those labeled with the SMI-32 antibody were in four different clusters. Yellow fluorescent protein expressing cells were distributed within 13 of the 14 clusters identified here, which demonstrates that yellow fluorescent protein expression is a useful method for labeling virtually the entire population of mouse retinal ganglion cells. Collectively, these findings provide a valuable baseline for future studies dealing with the effects of genetic mutations on the morphological development of these neurons.

  17. The effect of additives on the Cu 2O crystal morphology in acetate bath by electrodeposition

    NASA Astrophysics Data System (ADS)

    Sun, Fang; Guo, Yupeng; Tian, Yumei; Zhang, Jidong; Lv, Xiaotang; Li, Minggang; Zheng, Yunhui; Wang, Zichen

    2008-01-01

    Cuprous oxide (Cu 2O) thin films were formed on indium-doped tin oxide (ITO) covered glass substrates by cathodic deposition of cupric acetate. The influence of additives on crystal morphology of Cu 2O was studied in acetate bath. We found that the simple salts contained Cl - ions in electrolyte could change the crystal morphology. It was shown that the morphology evolved from star like to cube like by increasing the concentration of Cl - ions of the capping agents, which indicated that Cu 2O crystal morphology varied with the Cl - ions concentration.

  18. Cells with dendritic cell morphology and immunophenotype, binuclear morphology, and immunosuppressive function in dendritic cell cultures.

    PubMed

    Dong, Rong; Moulding, Dale; Himoudi, Nourredine; Adams, Stuart; Bouma, Gerben; Eddaoudi, Ayad; Basu, B Piku; Derniame, Sophie; Chana, Prabhjoat; Duncan, Andrew; Anderson, John

    2011-01-01

    Culturing of human peripheral blood CD14 positive monocytes is a method for generation of dendritic cells (DCs) for experimental purposes or for use in clinical grade vaccines. When culturing human DCs in this manner for clinical vaccine production, we noticed that 5-10% of cells within the bulk culture were binuclear or multiple nuclear, but had typical dendritic cell morphology and immunophenotype. We refer to the cells as binuclear cells in dendritic cell cultures (BNiDCs). By using single cell PCR analysis of mitochondrial DNA polymorphisms we demonstrated that approximately 20-25% of cells in DC culture undergo a fusion event. Flow sorted BNiDC express low HLA-DR and IL-12p70, but high levels of IL-10. In mixed lymphocyte reactions, purified BNiDC suppressed lymphocyte proliferation. Blockade of dendritic cell-specific transmembrane protein (DC-STAMP) decreased the number of binuclear cells in DC cultures. BNiDC represent a potentially tolerogenic population within DC preparations for clinical use.

  19. Cryptococcal Cell Morphology Affects Host Cell Interactions and Pathogenicity

    PubMed Central

    Nielsen, Judith N.; Charlier, Caroline; Baltes, Nicholas J.; Chrétien, Fabrice; Heitman, Joseph; Dromer, Françoise; Nielsen, Kirsten

    2010-01-01

    Cryptococcus neoformans is a common life-threatening human fungal pathogen. The size of cryptococcal cells is typically 5 to 10 µm. Cell enlargement was observed in vivo, producing cells up to 100 µm. These morphological changes in cell size affected pathogenicity via reducing phagocytosis by host mononuclear cells, increasing resistance to oxidative and nitrosative stress, and correlated with reduced penetration of the central nervous system. Cell enlargement was stimulated by coinfection with strains of opposite mating type, and ste3aΔ pheromone receptor mutant strains had reduced cell enlargement. Finally, analysis of DNA content in this novel cell type revealed that these enlarged cells were polyploid, uninucleate, and produced daughter cells in vivo. These results describe a novel mechanism by which C. neoformans evades host phagocytosis to allow survival of a subset of the population at early stages of infection. Thus, morphological changes play unique and specialized roles during infection. PMID:20585559

  20. Customization of Aspergillus niger Morphology Through Addition of Talc Micro Particles

    PubMed Central

    Wucherpfennig, Thomas; Lakowitz, Antonia; Driouch, Habib; Krull, Rainer; Wittmann, Christoph

    2012-01-01

    The filamentous fungus A. niger is a widely used strain in a broad range of industrial processes from food to pharmaceutical industry. One of the most intriguing and often uncontrollable characteristics of this filamentous organism is its complex morphology. It ranges from dense spherical pellets to viscous mycelia (Figure 1). Various process parameters and ingredients are known to influence fungal morphology 1. Since optimal productivity correlates strongly with a specific morphological form, the fungal morphology often represents the bottleneck of productivity in industrial production. A straight forward and elegant approach to precisely control morphological shape is the addition of inorganic insoluble micro particles (like hydrous magnesium silicate, aluminum oxide or titanium silicate oxide) to the culture medium contributing to increased enzyme production 2-6. Since there is an obvious correlation between micro particle dependent morphology and enzyme production it is desirable to mathematically link productivity and morphological appearance. Therefore a quantitative precise and holistic morphological description is targeted. Thus, we present a method to generate and characterize micro particle dependent morphological structures and to correlate fungal morphology with productivity (Figure 1) which possibly contributes to a better understanding of the morphogenesis of filamentous microorganisms. The recombinant strain A. niger SKAn1015 is cultivated for 72 h in a 3 L stirred tank bioreactor. By addition of talc micro particles in concentrations of 1 g/L, 3 g/L and 10 g/L prior to inoculation a variety of morphological structures is reproducibly generated. Sterile samples are taken after 24, 48 and 72 hours for determination of growth progress and activity of the produced enzyme. The formed product is the high-value enzyme β-fructofuranosidase, an important biocatalyst for neo-sugar formation in food or pharmaceutical industry, which catalyzes among others the

  1. Customization of Aspergillus niger morphology through addition of talc micro particles.

    PubMed

    Wucherpfennig, Thomas; Lakowitz, Antonia; Driouch, Habib; Krull, Rainer; Wittmann, Christoph

    2012-03-15

    The filamentous fungus A. niger is a widely used strain in a broad range of industrial processes from food to pharmaceutical industry. One of the most intriguing and often uncontrollable characteristics of this filamentous organism is its complex morphology. It ranges from dense spherical pellets to viscous mycelia. Various process parameters and ingredients are known to influence fungal morphology. Since optimal productivity correlates strongly with a specific morphological form, the fungal morphology often represents the bottleneck of productivity in industrial production. A straight forward and elegant approach to precisely control morphological shape is the addition of inorganic insoluble micro particles (like hydrous magnesium silicate, aluminum oxide or titanium silicate oxide) to the culture medium contributing to increased enzyme production. Since there is an obvious correlation between micro particle dependent morphology and enzyme production it is desirable to mathematically link productivity and morphological appearance. Therefore a quantitative precise and holistic morphological description is targeted. Thus, we present a method to generate and characterize micro particle dependent morphological structures and to correlate fungal morphology with productivity which possibly contributes to a better understanding of the morphogenesis of filamentous microorganisms. The recombinant strain A. niger SKAn1015 is cultivated for 72 h in a 3 L stirred tank bioreactor. By addition of talc micro particles in concentrations of 1 g/L, 3 g/L and 10 g/L prior to inoculation a variety of morphological structures is reproducibly generated. Sterile samples are taken after 24, 48 and 72 hours for determination of growth progress and activity of the produced enzyme. The formed product is the high-value enzyme β-fructofuranosidase, an important biocatalyst for neo-sugar formation in food or pharmaceutical industry, which catalyzes among others the reaction of sucrose to

  2. Cell Shape Dependent Regulation of Nuclear Morphology

    PubMed Central

    Chen, Bo; Co, Carlos; Ho, Chia-Chi

    2015-01-01

    Recent studies suggest that actin filaments are essential in how a cell controls its nuclear shape. However, little is known about the relative importance of membrane tension in determining nuclear morphology. In this study, we used adhesive micropatterned substrates to alter the cellular geometry (aspect ratio, size, and shape) that allowed direct membrane tension or without membrane lateral contact with the nucleus and investigate nuclear shape remodeling and orientation on a series of rectangular shapes. Here we showed that at low cell aspect ratios the orientation of the nucleus was regulated by actin filaments while cells with high aspect ratios can maintain nuclear shape and orientation even when actin polymerization was blocked. A model adenocarcinoma cell showed similar behavior in the regulation of nuclear shape in response to changes in cell shape but actin filaments were essential in maintaining cell shape. Our results highlight the two distinct mechanisms to regulate nuclear shape through cell shape control and the difference between fibroblasts and a model cancerous cell in cell adhesion and cell shape control. PMID:26210179

  3. Limb blastema cell: a stem cell for morphological regeneration.

    PubMed

    Tamura, Koji; Ohgo, Shiro; Yokoyama, Hitoshi

    2010-01-01

    The limb blastema cell, which is a major source of mesenchymal components in the limb regenerate, serves as a stem cell that possesses an undifferentiated state and multipotency. A remarkable property of the limb blastema cell can be seen in its capability for morphogenesis. Elucidation of the molecular basis for morphological regeneration is essential for success in organ regeneration in humans, and characterization of limb blastema cells will provide many insights into how to create three-dimensional morphology during the regeneration process. In this review, we deal with positional memory, a key trait of the limb blastema cell in regard to morphological regeneration, making reference to classic surgical experiments, comparative descriptions of limb and fin blastemas, and genetic/epigenetic regulation of gene transcription. Urodele amphibians, anuran amphibians, and teleosts are likely to share fundamental mechanisms for morphological regeneration, but there are several differences in the process of regeneration, including the epigenetic conditions. Accumulation of knowledge of the molecular mechanisms and epigenetic modifications of gene activation in morphological regeneration of the model organisms for which an overview is provided in this review will lead to successful stimulation of regenerative capacity in amniotes, which only have a limited capability for morphological regeneration.

  4. Effect of Blend Composition and Additives on the Morphology of PCPDTBT:PC71BM Thin Films for Organic Photovoltaics.

    PubMed

    Schaffer, Christoph J; Schlipf, Johannes; Dwi Indari, Efi; Su, Bo; Bernstorff, Sigrid; Müller-Buschbaum, Peter

    2015-09-30

    The use of solvent additives in the fabrication of bulk heterojunction polymer:fullerene solar cells allows to boost efficiencies in several low bandgap polymeric systems. It is known that solvent additives tune the nanometer scale morphology of the bulk heterojunction. The full mechanism of efficiency improvement is, however, not completely understood. In this work, we investigate the influences of blend composition and the addition of 3 vol % 1,8-octanedithiol (ODT) as solvent additive on polymer crystallization and both, vertical and lateral morphologies of poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta [2,1-b;3,4-b']dithiophene)-alt-4,7(2,1,3-benzothiadiazole)] and [6,6]-phenyl C71-butyric acid methyl ester (PCPDTBT:PC71BM) blend thin films processed from chlorobenzene-based solutions. The nanoscale morphology is probed with grazing incidence small- and wide-angle X-ray scattering as well as X-ray reflectivity and complemented with UV/vis spectroscopy. In PCPDTBT:PC71BM films the use of ODT is found to lower the solubility of fullerene in the polymer matrix and to promote polymer crystallization, both vertical and lateral microphase separation with morphological coarsening, and formation of a fullerene-rich topping layer. The enhanced photovoltaic performance is explained by these findings.

  5. Morphology Studies of Polymer Bulk Heterojunction Solar Cells

    NASA Astrophysics Data System (ADS)

    Moon, Ji Sun

    Energy is a prerequisite for creating and sustaining life. The need for energy increases globally as the world's population and economy grow. However, conventional energy sources---fossil fuels---generate carbon dioxide and contribute to global warming, perhaps the most serious environmental problem of our time. Carbon dioxide-free energy is required to stop global warming. Polymer solar cells have been attracting a great deal of interest as a source of renewable energy with a great potential for low cost. Polymer bulk heterojunction (BHJ) solar cells have been greatly improved; the power conversion efficiency is already up to 9.2% making the future of the polymer solar cell very promising. This thesis is a study of the morphology of polymer:fullerene BHJ, one of the most critical and challenging parts of high efficiency polymer solar cells. To discover the morphology, cross-section as well as top-down transmission electron microscopy were used. The contrast was achieved by utilizing phase contrast microscopy. Thermal annealing, dependence of BHJ thickness, processing additives, solution sequential process and solution sequential process with the use of cosolvent that affects/controls the BHJ morphology are studied in detail.

  6. Human Mesenchymal Stem Cell Morphology and Migration on Microtextured Titanium

    PubMed Central

    Banik, Brittany L.; Riley, Thomas R.; Platt, Christina J.; Brown, Justin L.

    2016-01-01

    The implant used in spinal fusion procedures is an essential component to achieving successful arthrodesis. At the cellular level, the implant impacts healing and fusion through a series of steps: first, mesenchymal stem cells (MSCs) need to adhere and proliferate to cover the implant; second, the MSCs must differentiate into osteoblasts; third, the osteoid matrix produced by the osteoblasts needs to generate new bone tissue, thoroughly integrating the implant with the vertebrate above and below. Previous research has demonstrated that microtextured titanium is advantageous over smooth titanium and PEEK implants for both promoting osteogenic differentiation and integrating with host bone tissue; however, no investigation to date has examined the early morphology and migration of MSCs on these surfaces. This study details cell spreading and morphology changes over 24 h, rate and directionality of migration 6–18 h post-seeding, differentiation markers at 10 days, and the long-term morphology of MSCs at 7 days, on microtextured, acid-etched titanium (endoskeleton), smooth titanium, and smooth PEEK surfaces. The results demonstrate that in all metrics, the two titanium surfaces outperformed the PEEK surface. Furthermore, the rough acid-etched titanium surface presented the most favorable overall results, demonstrating the random migration needed to efficiently cover a surface in addition to morphologies consistent with osteoblasts and preosteoblasts. PMID:27243001

  7. Morphology and Performance of Polymer Solar Cell Characterized by DPD Simulation and Graph Theory.

    PubMed

    Du, Chunmiao; Ji, Yujin; Xue, Junwei; Hou, Tingjun; Tang, Jianxin; Lee, Shuit-Tong; Li, Youyong

    2015-11-19

    The morphology of active layers in the bulk heterojunction (BHJ) solar cells is critical to the performance of organic photovoltaics (OPV). Currently, there is limited information for the morphology from transmission electron microscopy (TEM) techniques. Meanwhile, there are limited approaches to predict the morphology /efficiency of OPV. Here we use Dissipative Particle Dynamics (DPD) to determine 3D morphology of BHJ solar cells and show DPD to be an efficient approach to predict the 3D morphology. Based on the 3D morphology, we estimate the performance indicator of BHJ solar cells by using graph theory. Specifically, we study poly (3-hexylthiophene)/[6, 6]-phenyl-C61butyric acid methyl ester (P3HT/PCBM) BHJ solar cells. We find that, when the volume fraction of PCBM is in the region 0.4 ∼ 0.5, P3HT/PCBM will show bi-continuous morphology and optimum performance, consistent with experimental results. Further, the optimum temperature (413 K) for the morphology and performance of P3HT/PCBM is in accord with annealing results. We find that solvent additive plays a critical role in the desolvation process of P3HT/PCBM BHJ solar cell. Our approach provides a direct method to predict dynamic 3D morphology and performance indicator for BHJ solar cells.

  8. Morphology and Performance of Polymer Solar Cell Characterized by DPD Simulation and Graph Theory

    NASA Astrophysics Data System (ADS)

    Du, Chunmiao; Ji, Yujin; Xue, Junwei; Hou, Tingjun; Tang, Jianxin; Lee, Shuit-Tong; Li, Youyong

    2015-11-01

    The morphology of active layers in the bulk heterojunction (BHJ) solar cells is critical to the performance of organic photovoltaics (OPV). Currently, there is limited information for the morphology from transmission electron microscopy (TEM) techniques. Meanwhile, there are limited approaches to predict the morphology /efficiency of OPV. Here we use Dissipative Particle Dynamics (DPD) to determine 3D morphology of BHJ solar cells and show DPD to be an efficient approach to predict the 3D morphology. Based on the 3D morphology, we estimate the performance indicator of BHJ solar cells by using graph theory. Specifically, we study poly (3-hexylthiophene)/[6, 6]-phenyl-C61butyric acid methyl ester (P3HT/PCBM) BHJ solar cells. We find that, when the volume fraction of PCBM is in the region 0.4 ∼ 0.5, P3HT/PCBM will show bi-continuous morphology and optimum performance, consistent with experimental results. Further, the optimum temperature (413 K) for the morphology and performance of P3HT/PCBM is in accord with annealing results. We find that solvent additive plays a critical role in the desolvation process of P3HT/PCBM BHJ solar cell. Our approach provides a direct method to predict dynamic 3D morphology and performance indicator for BHJ solar cells.

  9. Morphology and Performance of Polymer Solar Cell Characterized by DPD Simulation and Graph Theory

    PubMed Central

    Du, Chunmiao; Ji, Yujin; Xue, Junwei; Hou, Tingjun; Tang, Jianxin; Lee, Shuit-Tong; Li, Youyong

    2015-01-01

    The morphology of active layers in the bulk heterojunction (BHJ) solar cells is critical to the performance of organic photovoltaics (OPV). Currently, there is limited information for the morphology from transmission electron microscopy (TEM) techniques. Meanwhile, there are limited approaches to predict the morphology /efficiency of OPV. Here we use Dissipative Particle Dynamics (DPD) to determine 3D morphology of BHJ solar cells and show DPD to be an efficient approach to predict the 3D morphology. Based on the 3D morphology, we estimate the performance indicator of BHJ solar cells by using graph theory. Specifically, we study poly (3-hexylthiophene)/[6, 6]-phenyl-C61butyric acid methyl ester (P3HT/PCBM) BHJ solar cells. We find that, when the volume fraction of PCBM is in the region 0.4 ∼ 0.5, P3HT/PCBM will show bi-continuous morphology and optimum performance, consistent with experimental results. Further, the optimum temperature (413 K) for the morphology and performance of P3HT/PCBM is in accord with annealing results. We find that solvent additive plays a critical role in the desolvation process of P3HT/PCBM BHJ solar cell. Our approach provides a direct method to predict dynamic 3D morphology and performance indicator for BHJ solar cells. PMID:26581407

  10. TiO2 anode materials for lithium-ion batteries with different morphology and additives

    NASA Astrophysics Data System (ADS)

    Liu, Xiang; Ng, Yip Hang; Leung, Yu Hang; Liu, Fangzhou; Djurišic, Aleksandra B.; Xie, Mao Hai; Chan, Wai Kin

    2014-03-01

    Electrochemical performances of different TiO2 nanostructures, TiO2/CNT composite and TiO2 with titanium isopropoxide (TTIP) treatment anode were investigated. For different TiO2 nanostructures, we investigated vertically aligned TiO2 nanotubes on Ti foil and TiO2 nanotube-powders fabricated by rapid breakdown anodization technique. The morphology of the prepared samples was characterized by scanning probe microscopy (SEM). The electrochemical lithium storage abilities were studied by galvanostatic method. In addition, carbon nanotubes (CNT) additives and solution treatment process of TiO2 anode were investigated, and the results show that the additives and treatment could enhance the cycling performance of the TiO2 anode on lithium ion batteries.

  11. Synchrotron X-ray CT characterization of titanium parts fabricated by additive manufacturing. Part I. Morphology.

    PubMed

    Scarlett, Nicola Vivienne Yorke; Tyson, Peter; Fraser, Darren; Mayo, Sheridan; Maksimenko, Anton

    2016-07-01

    Synchrotron X-ray tomography has been applied to the study of titanium parts fabricated by additive manufacturing (AM). The AM method employed here was the Arcam EBM(®) (electron beam melting) process which uses powdered titanium alloy, Ti64 (Ti alloy with approximately 6%Al and 4%V), as the feed and an electron beam for the sintering/welding. The experiment was conducted on the Imaging and Medical Beamline of the Australian Synchrotron. Samples were chosen to examine the effect of build direction and complexity of design on the surface morphology and final dimensions of the piece.

  12. Correlating the morphological and light scattering properties of biological cells

    NASA Astrophysics Data System (ADS)

    Moran, Marina

    The scattered light pattern from a biological cell is greatly influenced by the internal structure and optical properties of the cell. This research project examines the relationships between the morphological and scattering properties of biological cells through numerical simulations. The mains goals are: (1) to develop a procedure to analytically model biological cells, (2) to quantitatively study the effects of a range of cell characteristics on the features of the light scattering patterns, and (3) to classify cells based on the features of their light scattering patterns. A procedure to create an analytical cell model was developed which extracted structural information from the confocal microscopic images of cells and allowed for the alteration of the cell structure in a controlled and systematic way. The influence of cell surface roughness, nuclear size, and mitochondrial volume density, spatial distribution, size and shape on the light scattering patterns was studied through numerical simulations of light scattering using the Discrete Dipole Approximation. It was found that the light scattering intensity in the scattering angle range of 25° to 45° responded to changes in the surface fluctuation of the cell and the range of 90° to 110° was well suited for characterization of mitochondrial density and nuclear size. A comparison of light scattering pattern analysis methods revealed that the angular distribution of the scattered light and Gabor filters were most helpful in differentiating between the cell characteristics. In addition, a measured increase in the Gabor energy of the light scattering patterns in response to an increase in the complexity of the cell models suggested that a complex nuclear structure and mitochondria should be included when modeling biological cells for light scattering simulations. Analysis of the scattering pattern features with Gabor filters resulted in discrimination of the cell models according to cell surface roughness

  13. Synthesis of barium and strontium carbonate crystals with unusual morphologies using an organic additive

    NASA Astrophysics Data System (ADS)

    Chen, Long; Jiang, Jizhong; Bao, Zuben; Pan, Jian; Xu, Weibing; Zhou, Lili; Wu, Zhigang; Chen, Xu

    2013-12-01

    In this paper, strontium carbonate (SrCO3) and barium carbonate (BaCO3) crystals were synthesized in the presence of an organic additive-hexamethylenetetramine (HMT) using two CO2 sources. Scanning electron microscopy and X-ray powder diffractometry were used to characterize the products. The results showed that the morphologies of orthorhombic strontianite SrCO3 transformed from branch-like to flower-like, and to capsicum-like at last, while the morphologies of BaCO3 change from fiber-like to branchlike, and to rod-like finally with an increase of the molar ratio HMT/Sr2+ and HMT/Ba2+ from 0.2 to 10 using ammonium carbonate as CO2 source. When using diethyl carbonate instead of ammonium carbonate as CO2 source, SrCO3 flowers aggregated by rods and BaCO3 shuttles were formed. The possible formation mechanisms of SrCO3 and BaCO3 crystals obtained in different conditions were also discussed.

  14. Variations in cell morphology in the canine cruciate ligament complex.

    PubMed

    Smith, K D; Vaughan-Thomas, A; Spiller, D G; Clegg, P D; Innes, J F; Comerford, E J

    2012-08-01

    Cell morphology may reflect the mechanical environment of tissues and influence tissue physiology and response to injury. Normal cruciate ligaments (CLs) from disease-free stifle joints were harvested from dog breeds with a high (Labrador retriever) and low (Greyhound) risk of cranial cruciate ligament (CCL) rupture. Antibodies against the cytoskeletal components vimentin and alpha tubulin were used to analyse cell morphology; nuclei were stained with 4',6-diamidino-2-phenylindole, and images were collected using conventional and confocal microscopy. Both cranial and caudal CLs contained cells of heterogenous morphologies. Cells were arranged between collagen bundles and frequently had cytoplasmic processes. Some of these processes were long (type A cells), others were shorter, thicker and more branched (type B cells), and some had no processes (type C cells). Processes were frequently shown to contact other cells, extending longitudinally and transversely through the CLs. Cells with longer processes had fusiform nuclei, and those with no processes had rounded nuclei and were more frequent in the mid-substance of both CLs. Cells with long processes were more commonly noted in the CLs of the Greyhound. As contact between cells may facilitate direct communication, variances in cell morphology between breeds at a differing risk of CCL rupture may reflect differences in CL physiology.

  15. Endothelial cell responses in terms of adhesion, proliferation, and morphology to stiffness of polydimethylsiloxane elastomer substrates.

    PubMed

    Ataollahi, Forough; Pramanik, Sumit; Moradi, Ali; Dalilottojari, Adel; Pingguan-Murphy, Belinda; Wan Abas, Wan Abu Bakar; Abu Osman, Noor Azuan

    2015-07-01

    Extracellular environments can regulate cell behavior because cells can actively sense their mechanical environments. This study evaluated the adhesion, proliferation and morphology of endothelial cells on polydimethylsiloxane (PDMS)/alumina (Al2 O3 ) composites and pure PDMS. The substrates were prepared from pure PDMS and its composites with 2.5, 5, 7.5, and 10 wt % Al2 O3 at a curing temperature of 50°C for 4 h. The substrates were then characterized by mechanical, structural, and morphological analyses. The cell adhesion, proliferation, and morphology of cultured bovine aortic endothelial (BAEC) cells on substrate materials were evaluated by using resazurin assay and 1,1'-dioctadecyl-1,3,3,3',3'-tetramethylindocarbocyanine perchlorate-acetylated LDL (Dil-Ac-LDL) cell staining, respectively. The composites (PDMS/2.5, 5, 7.5, and 10 wt % Al2 O3 ) exhibited higher stiffness than the pure PDMS substrate. The results also revealed that stiffer substrates promoted endothelial cell adhesion and proliferation and also induced spread morphology in the endothelial cells compared with lesser stiff substrates. Statistical analysis showed that the effect of time on cell proliferation depended on stiffness. Therefore, this study concludes that the addition of different Al2 O3 percentages to PDMS elevated substrate stiffness which in turn increased endothelial cell adhesion and proliferation significantly and induced spindle shape morphology in endothelial cells.

  16. Neuronize: a tool for building realistic neuronal cell morphologies

    PubMed Central

    Brito, Juan P.; Mata, Susana; Bayona, Sofia; Pastor, Luis; DeFelipe, Javier; Benavides-Piccione, Ruth

    2013-01-01

    This study presents a tool, Neuronize, for building realistic three-dimensional models of neuronal cells from the morphological information extracted through computer-aided tracing applications. Neuronize consists of a set of methods designed to build 3D neural meshes that approximate the cell membrane at different resolution levels, allowing a balance to be reached between the complexity and the quality of the final model. The main contribution of the present study is the proposal of a novel approach to build a realistic and accurate 3D shape of the soma from the incomplete information stored in the digitally traced neuron, which usually consists of a 2D cell body contour. This technique is based on the deformation of an initial shape driven by the position and thickness of the first order dendrites. The addition of a set of spines along the dendrites completes the model, building a final 3D neuronal cell suitable for its visualization in a wide range of 3D environments. PMID:23761740

  17. Effect of hydroxyapatite surface morphology on cell adhesion.

    PubMed

    Iwamoto, Takashi; Hieda, Yohki; Kogai, Yasumichi

    2016-12-01

    We obtained hydroxyapatite (HAp) materials as a block by mixing HAp nanoparticles and polymer, and then calcining the mixtures. The surface morphology of the HAp materials was tuned by varying heat treatment conditions. After calcining the mixtures at 1200 or 800°C for 4h, the surface morphology of the HAp materials was flat or convexo-concave, respectively. The flat surface morphology, which showed micrometer-ordered grain boundaries, was formed by the aggregation of HAp nanoparticles. On the other hand, the convexo-concave surface morphology resulted from the agglomeration of HAp nanoparticles after heat treatment at 800°C for 4h with nanometer-ordered particle size. We tested cell adhesion to HAp materials with flat or convexo-concave surface morphology and found that cells adhered well to the flat HAp materials but not to the convexo-concave HAp materials. This technique for selectively preparing HAp materials with flat or convexo-concave surface morphology was very easy because we merely mixed commercial HAp nanoparticles with polymer and then calcined the mixtures. As a result, the heat treatment temperature affected the surface morphology of our HAp materials, and their surface morphologies contributed to cell adhesion independently of other material properties.

  18. Nanoparticle Induced Cell Magneto-Rotation: Monitoring Morphology, Stress and Drug Sensitivity of a Suspended Single Cancer Cell

    PubMed Central

    Elbez, Remy; McNaughton, Brandon H.; Patel, Lalit; Pienta, Kenneth J.; Kopelman, Raoul

    2011-01-01

    Single cell analysis has allowed critical discoveries in drug testing, immunobiology and stem cell research. In addition, a change from two to three dimensional growth conditions radically affects cell behavior. This already resulted in new observations on gene expression and communication networks and in better predictions of cell responses to their environment. However, it is still difficult to study the size and shape of single cells that are freely suspended, where morphological changes are highly significant. Described here is a new method for quantitative real time monitoring of cell size and morphology, on single live suspended cancer cells, unconfined in three dimensions. The precision is comparable to that of the best optical microscopes, but, in contrast, there is no need for confining the cell to the imaging plane. The here first introduced cell magnetorotation (CM) method is made possible by nanoparticle induced cell magnetization. By using a rotating magnetic field, the magnetically labeled cell is actively rotated, and the rotational period is measured in real-time. A change in morphology induces a change in the rotational period of the suspended cell (e.g. when the cell gets bigger it rotates slower). The ability to monitor, in real time, cell swelling or death, at the single cell level, is demonstrated. This method could thus be used for multiplexed real time single cell morphology analysis, with implications for drug testing, drug discovery, genomics and three-dimensional culturing. PMID:22180784

  19. Surface topography during neural stem cell differentiation regulates cell migration and cell morphology.

    PubMed

    Czeisler, Catherine; Short, Aaron; Nelson, Tyler; Gygli, Patrick; Ortiz, Cristina; Catacutan, Fay Patsy; Stocker, Ben; Cronin, James; Lannutti, John; Winter, Jessica; Otero, José Javier

    2016-12-01

    We sought to determine the contribution of scaffold topography to the migration and morphology of neural stem cells by mimicking anatomical features of scaffolds found in vivo. We mimicked two types of central nervous system scaffolds encountered by neural stem cells during development in vitro by constructing different diameter electrospun polycaprolactone (PCL) fiber mats, a substrate that we have shown to be topographically similar to brain scaffolds. We compared the effects of large fibers (made to mimic blood vessel topography) with those of small-diameter fibers (made to mimic radial glial process topography) on the migration and differentiation of neural stem cells. Neural stem cells showed differential migratory and morphological reactions with laminin in different topographical contexts. We demonstrate, for the first time, that neural stem cell biological responses to laminin are dependent on topographical context. Large-fiber topography without laminin prevented cell migration, which was partially reversed by treatment with rock inhibitor. Cell morphology complexity assayed by fractal dimension was inhibited in nocodazole- and cytochalasin-D-treated neural precursor cells in large-fiber topography, but was not changed in small-fiber topography with these inhibitors. These data indicate that cell morphology has different requirements on cytoskeletal proteins dependent on the topographical environment encountered by the cell. We propose that the physical structure of distinct scaffolds induces unique signaling cascades that regulate migration and morphology in embryonic neural precursor cells. J. Comp. Neurol. 524:3485-3502, 2016. © 2016 Wiley Periodicals, Inc.

  20. Changes, and the Relevance Thereof, in Mitochondrial Morphology during Differentiation into Endothelial Cells

    PubMed Central

    Shin, Ji Won; Park, So Hee; Kang, Yun Gyeong; Wu, Yanru; Choi, Hyun Ju

    2016-01-01

    The roles of mitochondria in various physiological functions of vascular endothelial cells have been investigated extensively. Morphological studies in relation to physiological functions have been performed. However, there have been few reports of morphological investigations related to stem cell differentiation. This was the first morphological study of mitochondria in relation to endothelial differentiation and focused on quantitative analysis of changes in mitochondrial morphology, number, area, and length during differentiation of human mesenchymal stem cells (hMSCs) into endothelial-like cells. To induce differentiation, we engaged vascular endothelial growth factors and flow-induced shear stress. Cells were classified according to the expression of von Willebrand factor as hMSCs, differentiating cells, and almost fully differentiated cells. Based on imaging analysis, we investigated changes in mitochondrial number, area, and length. In addition, mitochondrial networks were quantified on a single-mitochondrion basis by introducing a branch form factor. The data indicated that the mitochondrial number, area per cell, and length were decreased with differentiation. The mitochondrial morphology became simpler with progression of differentiation. These findings could be explained in view of energy level during differentiation; a higher level of energy is needed during differentiation, with larger numbers of mitochondria with branches. Application of this method to differentiation into other lineages will explain the energy levels required to control stem cell differentiation. PMID:27517609

  1. A novel mechanotactic 3D modeling of cell morphology

    NASA Astrophysics Data System (ADS)

    Jamaleddin Mousavi, Seyed; Hamdy Doweidar, Mohamed

    2014-08-01

    Cell morphology plays a critical role in many biological processes, such as cell migration, tissue development, wound healing and tumor growth. Recent investigations demonstrate that, among other stimuli, cells adapt their shapes according to their substrate stiffness. Until now, the development of this process has not been clear. Therefore, in this work, a new three-dimensional (3D) computational model for cell morphology has been developed. This model is based on a previous cell migration model presented by the same authors. The new model considers that during cell-substrate interaction, cell shape is governed by internal cell deformation, which leads to an accurate prediction of the cell shape according to the mechanical characteristic of its surrounding micro-environment. To study this phenomenon, the model has been applied to different numerical cases. The obtained results, which are qualitatively consistent with well-known related experimental works, indicate that cell morphology not only depends on substrate stiffness but also on the substrate boundary conditions. A cell located within an unconstrained soft substrate (several kPa) with uniform stiffness is unable to adhere to its substrate or to send out pseudopodia. When the substrate stiffness increases to tens of kPa (intermediate and rigid substrates), the cell can adequately adhere to its substrate. Subsequently, as the traction forces exerted by the cell increase, the cell elongates and its shape changes. Within very stiff (hard) substrates, the cell cannot penetrate into its substrate or send out pseudopodia. On the other hand, a cell is found to be more elongated within substrates with a constrained surface. However, this elongation decreases when the cell approaches it. It can be concluded that the higher the net traction force, the greater the cell elongation, the larger the cell membrane area, and the less random the cell alignment.

  2. MORPHOLOGICAL ABERRATION OF ARTHROBACTER GLOBIFORMIS CELLS DUE TO BIOTIN DEFICIENCY.

    PubMed

    CHAN, E C

    1964-03-01

    Chan, E. C. S. (University of New Brunswick, Fredericton, New Brunswick, Canada). Morphological aberration of Arthrobacter globiformis cells due to biotin deficiency. J. Bacteriol. 87:641-651. 1964.-Morphological aberration of Arthrobacter globiformis strain 425 was shown to occur during growth in a chemically defined medium without added biotin. Such aberrant cells could revert back to normal coccoid forms upon inoculation into fresh medium supplemented with the vitamin. This abnormal cellular development occurred even when there was good growth (turbidity) or increase in total cell mass. Light photomicrographs of negative and cell-wall stains of the organism at different times of the morphological growth cycle are presented in support of these observations. The relationship between cellular aberration and the biochemical role of biotin is briefly discussed.

  3. Single-cell resolution of morphological changes in hemogenic endothelium.

    PubMed

    Bos, Frank L; Hawkins, John S; Zovein, Ann C

    2015-08-01

    Endothelial-to-hematopoietic transition (EHT) occurs within a population of hemogenic endothelial cells during embryogenesis, and leads to the formation of the adult hematopoietic system. Currently, the prospective identification of specific endothelial cells that will undergo EHT, and the cellular events enabling this transition, are not known. We set out to define precisely the morphological events of EHT, and to correlate cellular morphology with the expression of the transcription factors RUNX1 and SOX17. A novel strategy was developed to allow for correlation of immunofluorescence data with the ultrastructural resolution of scanning electron microscopy. The approach can identify single endothelial cells undergoing EHT, as identified by the ratio of RUNX1 to SOX17 immunofluorescence levels, and the morphological changes associated with the transition. Furthermore, this work details a new technical resource that is widely applicable for correlative analyses of single cells in their native tissue environments.

  4. Characterization of Mode I Fracture and Morphological Properties of PLLA Blends with Addition of Lysine Triisocyanate

    NASA Astrophysics Data System (ADS)

    Vannaladsaysy, Vilay; Todo, Mitsugu

    Poly(L-lactic acid) (PLLA) was toughened by blending with three different ductile biopolymers such as poly (ε-caprolactone) (PCL), poly(butylene succinate-co-e-caprolactone) (PBSC), poly (butylene succinate-co-L-lactate) (PBSL). The blend ratio was fixed to 50:50. Lysine triisocyanate (LTI) was added to the blends as a compatibilizer. Characterizations such as Fourier transform infra-red (FT-IR) spectroscopy, field-emission electron microscope (FE-SEM), and mode I fracture test were used to characterize the effectiveness of LTI on the mechanical and morphological properties of various PLLA blends. It was found that PLLA/PCL blend shows the highest toughness energy among the binary blends. On the other hand, addition of LTI in PLLA/PBSC blend exhibits the best toughness property. Based on the FE-SEM observation, fractured surfaces of PLLA blends with LTI indicate ductile fracture with dense elongated fibrils. The largest damage zone is generated in the vicinity of crack-trip, suggesting that high energy dissipation occurred in the crack-trip region. FT-IR analysis also suggested that the NCO groups of LTI were acted as a compatibilizer, as the results of interaction between the two phases of the polymer blends.

  5. Effects of nutrient addition on leaf chemistry, morphology, and photosynthetic capacity of three bog shrubs.

    PubMed

    Bubier, Jill L; Smith, Rose; Juutinen, Sari; Moore, Tim R; Minocha, Rakesh; Long, Stephanie; Minocha, Subhash

    2011-10-01

    Plants in nutrient-poor environments typically have low foliar nitrogen (N) concentrations, long-lived tissues with leaf traits designed to use nutrients efficiently, and low rates of photosynthesis. We postulated that increasing N availability due to atmospheric deposition would increase photosynthetic capacity, foliar N, and specific leaf area (SLA) of bog shrubs. We measured photosynthesis, foliar chemistry and leaf morphology in three ericaceous shrubs (Vaccinium myrtilloides, Ledum groenlandicum and Chamaedaphne calyculata) in a long-term fertilization experiment at Mer Bleue bog, Ontario, Canada, with a background deposition of 0.8 g N m(-2) a(-1). While biomass and chlorophyll concentrations increased in the highest nutrient treatment for C. calyculata, we found no change in the rates of light-saturated photosynthesis (A(max)), carboxylation (V(cmax)), or SLA with nutrient (N with and without PK) addition, with the exception of a weak positive correlation between foliar N and A(max) for C. calyculata, and higher V(cmax) in L. groenlandicum with low nutrient addition. We found negative correlations between photosynthetic N use efficiency (PNUE) and foliar N, accompanied by a species-specific increase in one or more amino acids, which may be a sign of excess N availability and/or a mechanism to reduce ammonium (NH(4)) toxicity. We also observed a decrease in foliar soluble Ca and Mg concentrations, essential minerals for plant growth, but no change in polyamines, indicators of physiological stress under conditions of high N accumulation. These results suggest that plants adapted to low-nutrient environments do not shift their resource allocation to photosynthetic processes, even after reaching N sufficiency, but instead store the excess N in organic compounds for future use. In the long term, bog species may not be able to take advantage of elevated nutrients, resulting in them being replaced by species that are better adapted to a higher nutrient environment.

  6. Design of Bicontinuous Donor/Acceptor Morphologies for Use as Organic Solar Cell Active Layers

    NASA Astrophysics Data System (ADS)

    Kipp, Dylan; Mok, Jorge; Verduzco, Rafael; Ganesan, Venkat

    Two of the primary challenges limiting the marketability of organic solar cells are i) the smaller device efficiency of the organic solar cell relative to the conventional silicon-based solar cell and ii) the long term thermal instability of the device active layer. The achievement of equilibrium donor/acceptor morphologies with the characteristics believed to yield high device performance characteristics could address each of these two challenges. In this work, we present the results of a combined simulations and experiments-based approach to investigate if a conjugated BCP additive can be used to control the self-assembled morphologies taken on by conjugated polymer/PCBM mixtures. First, we use single chain in mean field Monte Carlo simulations to identify regions within the conjugated polymer/PCBM composition space in which addition of copolymers can lead to bicontinuous equilibrium morphologies with high interfacial areas and nanoscale dimensions. Second, we conduct experiments as directed by the simulations to achieve such morphologies in the PTB7 + PTB7- b-PNDI + PCBM model blend. We characterize the results of our experiments via a combination of transmission electron microscopy and X-ray scattering techniques and demonstrate that the morphologies from experiments agree with those predicted in simulations. Accordingly, these results indicate that the approach utilized represents a promising approach to intelligently design the morphologies taken on by organic solar cell active layers.

  7. Formulation strategies for optimizing the morphology of polymeric bulk heterojunction organic solar cells: a brief review

    NASA Astrophysics Data System (ADS)

    Vongsaysy, Uyxing; Bassani, Dario M.; Servant, Laurent; Pavageau, Bertrand; Wantz, Guillaume; Aziz, Hany

    2014-01-01

    Polymeric bulk heterojunction (BHJ) organic solar cells represent one of the most promising technologies for renewable energy with a low fabrication cost. Control over BHJ morphology is one of the key factors in obtaining high-efficiency devices. This review focuses on formulation strategies for optimizing the BHJ morphology. We address how solvent choice and the introduction of processing additives affect the morphology. We also review a number of recent studies concerning prediction methods that utilize the Hansen solubility parameters to develop efficient solvent systems.

  8. Counting white blood cells using morphological granulometries

    NASA Astrophysics Data System (ADS)

    Theera-Umpon, Nipon; Gader, Paul D.

    2000-04-01

    We describe a modification of the mixture proportion estimation algorithm based on the granulometric mixing theorem. The modified algorithm is applied to the problem of counting different types of white blood cells in bone marrow images. In principle, the algorithm can be used to count the proportion of cells in each class without explicitly segmenting and classifying them. The direct application of the original algorithm does not converge well for more than two classes. The modified algorithm uses prior statistics to initially segment the mixed pattern spectrum and then applies the one-primitive estimation algorithm to each initial component. Applying the algorithm to one class at a time results in better convergence. The counts produced by the modified algorithm on six classes of cells--myeloblast, promyelocyte, myelocyte, metamyelocyte, band, and PolyMorphoNuclear--are very close to the human expert's numbers; the deviation of the algorithm counts is similar to the deviation of counts produced by human experts. The important technical contributions are that the modified algorithm uses prior statistics for each shape class in place or prior knowledge of the total number of objects in an image, and it allows for more than one primitive from each class.

  9. Morphological and functional platelet abnormalities in Berkeley sickle cell mice.

    PubMed

    Shet, Arun S; Hoffmann, Thomas J; Jirouskova, Marketa; Janczak, Christin A; Stevens, Jacqueline R M; Adamson, Adewole; Mohandas, Narla; Manci, Elizabeth A; Cynober, Therese; Coller, Barry S

    2008-01-01

    Berkeley sickle cell mice are used as animal models of human sickle cell disease but there are no reports of platelet studies in this model. Since humans with sickle cell disease have platelet abnormalities, we studied platelet morphology and function in Berkeley mice (SS). We observed elevated mean platelet forward angle light scatter (FSC) values (an indirect measure of platelet volume) in SS compared to wild type (WT) (37+/-3.2 vs. 27+/-1.4, mean+/-SD; p<0.001), in association with moderate thrombocytopenia (505+/-49 x 10(3)/microl vs. 1151+/-162 x 10(3)/microl; p<0.001). Despite having marked splenomegaly, SS mice had elevated levels of Howell-Jolly bodies and "pocked" erythrocytes (p<0.001 for both) suggesting splenic dysfunction. SS mice also had elevated numbers of thiazole orange positive platelets (5+/-1% vs. 1+/-1%; p<0.001), normal to low plasma thrombopoietin levels, normal plasma glycocalicin levels, normal levels of platelet recovery, and near normal platelet life spans. Platelets from SS mice bound more fibrinogen and antibody to P-selectin following activation with a threshold concentration of a protease activated receptor (PAR)-4 peptide compared to WT mice. Enlarged platelets are associated with a predisposition to arterial thrombosis in humans and some humans with SCD have been reported to have large platelets. Thus, additional studies are needed to assess whether large platelets contribute either to pulmonary hypertension or the large vessel arterial occlusion that produces stroke in some children with sickle cell disease.

  10. Effect on the morphology and optical properties of CH3NH3PbI3 with additive of NH4Cl

    NASA Astrophysics Data System (ADS)

    Yan, Xiaoliang; Yang, Xiao; Wang, Ruizhi; Li, Heng; Sheng, Chuanxiang

    2017-02-01

    Rapid emergence of solar cells based on mixed organic-inorganic halide perovskite have led to high power conversion efficiencies of over 20% in recent years. Looking for a simple and convenient way to fine-control of the perovskite film morphology is becoming one of the main issues. In this work, we explore the effect of adding NH4Cl on crystallization process and optical properties of perovskite. With adding NH4Cl, the perovskite films prepared by one-step method present better morphology than films without adding NH4Cl, namely, smoother surface and better coverage which result in uniform and much more stable photoluminescence intensities as well as longer lifetime of photoexcitations. More importantly, the photovoltaic cells fabricated with the addition of the NH4Cl have far better performance than the cells without additives. Therefore, one-step fabrication method can also control the morphology of perovskite films finely for both optical application and solar cells with adding proper additive.

  11. Supramolecular Approaches to Nanoscale Morphological Control in Organic Solar Cells.

    PubMed

    Haruk, Alexander M; Mativetsky, Jeffrey M

    2015-06-11

    Having recently surpassed 10% efficiency, solar cells based on organic molecules are poised to become a viable low-cost clean energy source with the added advantages of mechanical flexibility and light weight. The best-performing organic solar cells rely on a nanostructured active layer morphology consisting of a complex organization of electron donating and electron accepting molecules. Although much progress has been made in designing new donor and acceptor molecules, rational control over active layer morphology remains a central challenge. Long-term device stability is another important consideration that needs to be addressed. This review highlights supramolecular strategies for generating highly stable nanostructured organic photovoltaic active materials by design.

  12. Lanthanum Nitrate As Electrolyte Additive To Stabilize the Surface Morphology of Lithium Anode for Lithium-Sulfur Battery.

    PubMed

    Liu, Sheng; Li, Guo-Ran; Gao, Xue-Ping

    2016-03-01

    Lithium-sulfur (Li-S) battery is regarded as one of the most promising candidates beyond conventional lithium ion batteries. However, the instability of the metallic lithium anode during lithium electrochemical dissolution/deposition is still a major barrier for the practical application of Li-S battery. In this work, lanthanum nitrate, as electrolyte additive, is introduced into Li-S battery to stabilize the surface of lithium anode. By introducing lanthanum nitrate into electrolyte, a composite passivation film of lanthanum/lithium sulfides can be formed on metallic lithium anode, which is beneficial to decrease the reducibility of metallic lithium and slow down the electrochemical dissolution/deposition reaction on lithium anode for stabilizing the surface morphology of metallic Li anode in lithium-sulfur battery. Meanwhile, the cycle stability of the fabricated Li-S cell is improved by introducing lanthanum nitrate into electrolyte. Apparently, lanthanum nitrate is an effective additive for the protection of lithium anode and the cycling stability of Li-S battery.

  13. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  14. Morphological effect of oscillating magnetic nanoparticles in killing tumor cells

    NASA Astrophysics Data System (ADS)

    Cheng, Dengfeng; Li, Xiao; Zhang, Guoxin; Shi, Hongcheng

    2014-04-01

    Forced oscillation of spherical and rod-shaped iron oxide magnetic nanoparticles (MNPs) via low-power and low-frequency alternating magnetic field (AMF) was firstly used to kill cancer cells in vitro. After being loaded by human cervical cancer cells line (HeLa) and then exposed to a 35-kHz AMF, MNPs mechanically damaged cell membranes and cytoplasm, decreasing the cell viability. It was found that the concentration and morphology of the MNPs significantly influenced the cell-killing efficiency of oscillating MNPs. In this preliminary study, when HeLa cells were pre-incubated with 100 μg/mL rod-shaped MNPs (rMNP, length of 200 ± 50 nm and diameter of 50 to 120 nm) for 20 h, MTT assay proved that the cell viability decreased by 30.9% after being exposed to AMF for 2 h, while the cell viability decreased by 11.7% if spherical MNPs (sMNP, diameter of 200 ± 50 nm) were used for investigation. Furthermore, the morphological effect of MNPs on cell viability was confirmed by trypan blue assay: 39.5% rMNP-loaded cells and 15.1% sMNP-loaded cells were stained after being exposed to AMF for 2 h. It was also interesting to find that killing tumor cells at either higher (500 μg/mL) or lower (20 μg/mL) concentration of MNPs was less efficient than that achieved at 100 μg/mL concentration. In conclusion, the relatively asymmetric morphological rod-shaped MNPs can kill cancer cells more effectively than spherical MNPs when being exposed to AMF by virtue of their mechanical oscillations.

  15. Morphologic changes in basal cells during repair of tracheal epithelium.

    PubMed Central

    Wang, C. Z.; Evans, M. J.; Cox, R. A.; Burke, A. S.; Zhu, Q.; Herndon, D. N.; Barrow, R. E.

    1992-01-01

    Basal cells are differentiated with respect to junctional adhesion mechanisms and play a role in attachment of columnar epithelium to the basal lamina. Although much is known about nonciliated and ciliated cell differentiation during the repair process after injury, little is known about the basal cell. We studied the morphology of basal cells and quantitated junctional adhesion structures during repair of tracheal epithelium exposed to toxic cotton smoke. Ten adult ewes were given a smoke injury to a portion of the upper cervical trachea and were killed at 4, 6, 8, 10, and 18 days after injury for morphometric studies. At 4 days, there was a stratified reparative epithelium over the basal lamina, which was two to four cells in depth. The basal cells were identified by their hemidesmosome (HD) attachment to the basal lamina. Basal cells were about 69% larger than controls and flattened rather than columnar. The amount of HD attachment was 192% greater than controls. In contrast, volume density of cytokeratin filaments had decreased about 47%. Basal cells had returned to normal numbers and size and a columnar shape by day 18. The amount of desmosome (D) and HD attachment and volume density of cytokeratins had also reached control levels by day 18. These data indicate that morphology of basal cells changes during the initial stages of reparative regeneration but returns to normal by 18 days. Morphologic changes appear to reflect changes in size of the cell associated with cell division rather than differentiation of recently divided basal cells. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:1381564

  16. Morphology control of the perovskite films for efficient solar cells.

    PubMed

    Zheng, Lingling; Zhang, Danfei; Ma, Yingzhuang; Lu, Zelin; Chen, Zhijian; Wang, Shufeng; Xiao, Lixin; Gong, Qihuang

    2015-06-21

    In the past two years, the power conversion efficiency (PCE) of organic-inorganic hybrid perovskite solar cells has significantly increased up to 20.1%. These state-of-the-art new devices surpass other third-generation solar cells to become the most promising rival to the silicon-based solar cells. Since the morphology of the perovskite film is one of the most crucial factors to affect the performance of the device, many approaches have been developed for its improvement. This review provides a systematical summary of the methods for morphology control. Introductions and discussions on the mechanisms and relevant hotspots are also given. Understanding the growth process of perovskite crystallites has great benefits for further efficiency improvement and enlightens us to exploit new technologies for large-scale, low-cost and high-performance perovskite solar cells.

  17. [Effects of infusion media on human red blood cell morphology].

    PubMed

    Burova, O O; Gusev, A A; Petrikov, S S; Gusev, S A; Basyreva, L Iu

    2006-01-01

    The effect of various infusion media on the structure of human red blood cells was evaluated in vitro and in vivo. The in vitro experiments used 10% sodium chloride (NaCl) solution, 10% glucose solution, 20% albumin solution, Rheopolyglucin, HyperHAES solution (18 g of NaCl in combination with 60 g of hydroxyethylstarch (HES), 200/0.5), Voluven (HES 130/0.4/9:1), and a combination of hypertensive NaCl solution and Rheopolyglucin. The morphofunctional response of red blood cells was studied in the clinical setting when 6% Voluven solution (HES 130/0.4/ 9:1) and hypertensive NaCl and glucose solutions were used. It was established that 10% NaCl solution caused considerable changes in the morphology of red blood cells both in the experiment and in patients with severe brain injury. The magnitude of structural changes increased as blood NaCl concentrations became higher. 10% glucose solution, Voluven, Rheopolyglucin, and albumin did not virtually affect the structure of red blood cells. Infusion of Voluven (500 ml of 6% solution for 40 minutes) induced no changes in the morphology of red blood cells in the clinical setting. Among the test solutions used to correct intracranial hypertension (HyperHAES, 10% NaCl, a combination of rheopolyglucin and 10% NaCl), HyperHAES exerted the least effect on the morphology of red blood cells.

  18. Bovine oviductal epithelial cells: long term culture characterization and impact of insulin on cell morphology.

    PubMed

    Palma-Vera, S; Einspanier, R; Schoen, J

    2014-09-01

    In vitro models that resemble cell function in vivo are needed to understand oviduct physiology. This study aimed to assess cell functions and insulin effects on bovine oviductal epithelial cells (BOECs) cultured in an air-liquid interface. BOECs (n=6) were grown in conditioned Ham's F12, DMEM or Ham's F12/DMEM with 10% fetal calf serum (FCS) for 3 weeks. After selecting the most suitable medium (Ham's F12), increasing insulin concentrations (1 ng/mL, 20 ng/mL and 5 μg/mL) were applied, and cell morphology and trans-epithelial electrical resistance (TEER; n=4) were evaluated after 3 and 6 weeks. Keratin immunohistochemistry and mRNA expression of oviductal glycoprotein 1 (OVGP1) and progesterone receptor (PGR) were conducted (n=4) to assess cell differentiation. BOECs grown without insulin supplementation or with 1 ng/mL of insulin displayed polarization and secretory activity. However, cells exhibited only 50% of the height of their in vivo counterparts. Cultures supplemented with 20 ng/mL insulin showed the highest quality, but the 5 μg/mL concentration induced massive growth. TEER correlated negatively with insulin concentration (r=-0.459; p=0.009). OVGP1 and PGR transcripts were still detectable after 3 and 6 weeks. Cellular localization of keratins closely resembled that of BOECs in vivo. Cultures showed heterogeneous expression of PGR and OVGP1 in response to estradiol (10 pg/mL). In summary, BOECs grown for long term in an air-liquid interface expressed markers of cell differentiation. Additionally, insulin supplementation (20 ng/mL) improved the cell morphology in vitro.

  19. Morphology evolution in high-performance polymer solar cells processed from nonhalogenated solvent

    DOE PAGES

    Cai, Wanzhu; Liu, Peng; Jin, Yaocheng; ...

    2015-05-26

    A new processing protocol based on non-halogenated solvent and additive is developed to produce polymer solar cells with power conversion efficiencies better than those processed from commonly used halogenated solvent-additive pair. Morphology studies show that good performance correlates with a finely distributed nanomorphology with a well-defined polymer fibril network structure, which leads to balanced charge transport in device operation.

  20. Tendon cell outgrowth rates and morphology associated with kevlar-49.

    PubMed

    Zimmerman, M; Gordon, K E

    1988-12-01

    A rat tendon cell model was used to evaluate the in vitro biocompatibility of kevlar-49. The cell response to kevlar was compared to carbon AS-4 and nylon sutures. Three trials were run and cell growth rates were statistically similar for all the materials tested. A separate experiment was conducted in which the same fiber materials were placed in the same Petri dish. Again, the rates were similar for each material. Finally, the cells were observed with a scanning electron microscope, and the three classic cell morphologies associated with this tendon cell model were observed. Also, cellular attachment to the fiber and cellular encapsulation of the fiber were identical for the three materials tested. Kevlar-49 proved to be comparable to carbon AS4 and nylon sutures in terms of cellular response and cell outgrowth rates.

  1. Early Holocene human remains from the Argentinean Pampas: additional evidence for distinctive cranial morphology of early South Americans.

    PubMed

    Pucciarelli, Héctor M; Perez, S Ivan; Politis, Gustavo G

    2010-10-01

    The cranial morphology of Early Holocene American human samples is characterized by a long and narrow cranial vault, whereas more recent samples exhibit a shorter and wider cranial vault. Two hypotheses have been proposed to account for the morphological differences between early and late-American samples: (a) the migratory hypothesis that suggests that the morphological variation between early and late American samples was the result of a variable number of migratory waves; and (b) the local diversification hypothesis, that is, the morphological differences between early and late American samples were mainly generated by local, random (genetic drift), and nonrandom factors (selection and phenotypic plasticity). We present the first craniometric study of three early skulls from the Argentinean Pampas, dated ∼8,000 cal. years BP (Arroyo Seco 2, Chocorí, and La Tigra), and one associated with mega-faunal remains (Fontezuelas skull). In addition, we studied several Late Holocene samples. We show that the skulls from the Argentinean Pampas are morphologically similar to other Early Holocene American skulls (i.e., Lagoa Santa from Brazil, Tequendama, Checua, and Aguazuque from Colombia, Lauricocha from Peru, and early Mexicans) that exhibit long and narrow cranial vaults. These samples differ from the Late Holocene American samples that exhibit a shorter and wider cranial vault. Our results underscore the important differences in cranial morphology between early and late-American samples. However, we emphasize the need for further studies to discuss alternative hypotheses regarding such differences.

  2. Measurement of red blood cell mechanics during morphological changes.

    PubMed

    Park, YongKeun; Best, Catherine A; Badizadegan, Kamran; Dasari, Ramachandra R; Feld, Michael S; Kuriabova, Tatiana; Henle, Mark L; Levine, Alex J; Popescu, Gabriel

    2010-04-13

    The human red blood cell (RBC) membrane, a fluid lipid bilayer tethered to an elastic 2D spectrin network, provides the principal control of the cell's morphology and mechanics. These properties, in turn, influence the ability of RBCs to transport oxygen in circulation. Current mechanical measurements of RBCs rely on external loads. Here we apply a noncontact optical interferometric technique to quantify the thermal fluctuations of RBC membranes with 3 nm accuracy over a broad range of spatial and temporal frequencies. Combining this technique with a new mathematical model describing RBC membrane undulations, we measure the mechanical changes of RBCs as they undergo a transition from the normal discoid shape to the abnormal echinocyte and spherical shapes. These measurements indicate that, coincident with this morphological transition, there is a significant increase in the membrane's shear, area, and bending moduli. This mechanical transition can alter cell circulation and impede oxygen delivery.

  3. Dynamic and reversible surface topography influences cell morphology.

    PubMed

    Kiang, Jennifer D; Wen, Jessica H; del Álamo, Juan C; Engler, Adam J

    2013-08-01

    Microscale and nanoscale surface topography changes can influence cell functions, including morphology. Although in vitro responses to static topography are novel, cells in vivo constantly remodel topography. To better understand how cells respond to changes in topography over time, we developed a soft polyacrylamide hydrogel with magnetic nickel microwires randomly oriented in the surface of the material. Varying the magnetic field around the microwires reversibly induced their alignment with the direction of the field, causing the smooth hydrogel surface to develop small wrinkles; changes in surface roughness, ΔRRMS , ranged from 0.05 to 0.70 μm and could be oscillated without hydrogel creep. Vascular smooth muscle cell morphology was assessed when exposed to acute and dynamic topography changes. Area and shape changes occurred when an acute topographical change was imposed for substrates exceeding roughness of 0.2 μm, but longer-term oscillating topography did not produce significant changes in morphology irrespective of wire stiffness. These data imply that cells may be able to use topography changes to transmit signals as they respond immediately to changes in roughness.

  4. Influence of collagen addition on the thermal and morphological properties of chitosan/xanthan hydrogels.

    PubMed

    Horn, Marilia M; Martins, Virginia C A; Plepis, Ana Maria de Guzzi

    2015-09-01

    This study investigates the collagen influence on thermal and morphological characteristics of chitosan/xanthan hydrogels for potential tissue engineering applications. Anionic collagen was prepared by selective hydrolysis of type I collagen found in bovine tendons. Chitosan was obtained from the partial deacetylation of squid pen β-chitin and xanthan was acquired from Fluka. The hydrogels were obtained in different ratios and were characterized by thermal and morphological analysis. FT-IR suggested only electrostatic interactions between NH3(+) groups of chitosan and COO(-) groups of xanthan and collagen. Thermogravimetric curves showed that hydrogels contain a great amount of water (above 98%) and the presence of collagen does not change this characteristic. Freezing-bound water transition in DSC curves was shifted to higher values due to the increase of water/polymer interaction, mainly when different ratios of chitosan and xanthan were used. SEM images showed sheet-form structures with the presence of collagen promoting an increase in pore size.

  5. Organic solar cells: an overview focusing on active layer morphology.

    PubMed

    Benanti, Travis L; Venkataraman, D

    2006-01-01

    Solar cells constructed of organic materials are becoming increasingly efficient due to the discovery of the bulk heterojunction concept. This review provides an overview of organic solar cells. Topics covered include: a brief history of organic solar cell development; device construction, definitions, and characteristics; and heterojunction morphology and its relation to device efficiency in conjugated polymer/fullerene systems. The aim of this article is to show that researchers are developing a better understanding of how material structure relates to function and that they are applying this knowledge to build more efficient light-harvesting devices.

  6. Polydimethylsiloxane as a Macromolecular Additive for Enhanced Performance of Molecular Bulk Heterojunction Organic Solar Cells

    SciTech Connect

    Graham, Kenneth R.; Mei, Jianguo; Stalder, Romain; Shim, Jae Won; Cheun, Hyeunseok; Steffy, Fred; So, Franky; Kippelen, Bernard; Reynolds, John R.

    2011-03-15

    The effect of the macromolecular additive, polydimethylsiloxane (PDMS), on the performance of solution processed molecular bulk heterojunction solar cells is investigated, and the addition of PDMS is shown to improve device power conversion efficiency by ~70% and significantly reduce cell-to-cell variation, from a power conversion efficiency of 1.25 ± 0.37% with no PDMS to 2.16 ± 0.09% upon the addition of 0.1 mg/mL PDMS to the casting solution. The cells are based on a thiophene and isoindigo containing oligomer as the electron donor and [6,6]-phenyl-C61 butyric acid methyl ester (PC61BM) as the electron acceptor. PDMS is shown to have a strong influence on film morphology, with a significant decrease in film roughness and feature size observed. The morphology change leads to improved performance parameters, most notably an increase in the short circuit current density from 4.3 to 6.8 mA/cm2 upon addition of 0.1 mg/mL PDMS. The use of PDMS is of particular interest, as this additive appears frequently as a lubricant in plastic syringes commonly used in device fabrication; therefore, PDMS may unintentionally be incorporated into device active layers.

  7. Metal-air cell with performance enhancing additive

    DOEpatents

    Friesen, Cody A; Buttry, Daniel

    2015-11-10

    Systems and methods drawn to an electrochemical cell comprising a low temperature ionic liquid comprising positive ions and negative ions and a performance enhancing additive added to the low temperature ionic liquid. The additive dissolves in the ionic liquid to form cations, which are coordinated with one or more negative ions forming ion complexes. The electrochemical cell also includes an air electrode configured to absorb and reduce oxygen. The ion complexes improve oxygen reduction thermodynamics and/or kinetics relative to the ionic liquid without the additive.

  8. Quantitative methods to characterize morphological properties of cell lines.

    PubMed

    Mancia, Annalaura; Elliott, John T; Halter, Michael; Bhadriraju, Kiran; Tona, Alessandro; Spurlin, Tighe A; Middlebrooks, Bobby L; Baatz, John E; Warr, Gregory W; Plant, Anne L

    2012-07-01

    Descriptive terms are often used to characterize cells in culture, but the use of nonquantitative and poorly defined terms can lead to ambiguities when comparing data from different laboratories. Although recently there has been a good deal of interest in unambiguous identification of cell lines via their genetic markers, it is also critical to have definitive, quantitative metrics to describe cell phenotypic characteristics. Quantitative metrics of cell phenotype will aid the comparison of data from experiments performed at different times and in different laboratories where influences such as the age of the population and differences in culture conditions or protocols can potentially affect cellular metabolic state and gene expression in the absence of changes in the genetic profile. Here, we present examples of robust methodologies for quantitatively assessing characteristics of cell morphology and cell-cell interactions, and of growth rates of cells within the population. We performed these analyses with endothelial cell lines derived from dolphin, bovine and human, and with a mouse fibroblast cell line. These metrics quantify some characteristics of these cells lines that clearly distinguish them from one another, and provide quantitative information on phenotypic changes in one of the cell lines over large number of passages.

  9. Supramolecular Approaches to Nanoscale Morphological Control in Organic Solar Cells

    PubMed Central

    Haruk, Alexander M.; Mativetsky, Jeffrey M.

    2015-01-01

    Having recently surpassed 10% efficiency, solar cells based on organic molecules are poised to become a viable low-cost clean energy source with the added advantages of mechanical flexibility and light weight. The best-performing organic solar cells rely on a nanostructured active layer morphology consisting of a complex organization of electron donating and electron accepting molecules. Although much progress has been made in designing new donor and acceptor molecules, rational control over active layer morphology remains a central challenge. Long-term device stability is another important consideration that needs to be addressed. This review highlights supramolecular strategies for generating highly stable nanostructured organic photovoltaic active materials by design. PMID:26110382

  10. A spectral and morphologic method for white blood cell classification

    NASA Astrophysics Data System (ADS)

    Wang, Qian; Chang, Li; Zhou, Mei; Li, Qingli; Liu, Hongying; Guo, Fangmin

    2016-10-01

    The identification of white blood cells is important as it provides an assay for diagnosis of various diseases. To overcome the complexity and inaccuracy of traditional methods based on light microscopy, we proposed a spectral and morphologic method based on hyperspectral blood images. We applied mathematical morphology-based methods to extract spatial information and supervised method is employed for spectral analysis. Experimental results show that white blood cells could be segmented and classified into five types with an overall accuracy of more than 90%. Moreover, the experiments including spectral features reached higher accuracy than the spatial-only cases, with a maximum improvement of nearly 20%. By combing both spatial and spectral features, the proposed method provides higher classification accuracy than traditional methods.

  11. Effect of additives on the performance and morphology of sulfonated copoly (phthalazinone biphenyl ether sulfone) composite nanofiltration membranes☆

    NASA Astrophysics Data System (ADS)

    Guan, Shanshan; Zhang, Shouhai; Liu, Peng; Zhang, Guozhen; Jian, Xigao

    2014-03-01

    Sulfonated copoly (phthalazinone biphenyl ether sulfone) (SPPBES) composite nanofiltration membranes were fabricated by adding low molecular weight additives into SPPBES coating solutions during a dip coating process. Three selected additives: glycol, glycerol and hydroquinone were used in this work. The effect of additives on the membrane performance was studied and discussed in terms of rejection and permeation flux. Among all the composite membranes, the membrane prepared with glycol as an additive achieved the highest Na2SO4 rejection, and the membrane fabricated with glycerol as an additive exhibited the highest flux. The salts rejection of SPPBES composite membranes increased in the following order MgCl2 < NaCl ≤ MgSO4 < Na2SO4. The morphologies of the SPPBES composite membranes were characterized by SEM, it was found that the membrane prepared with hydroquinone showed a rough membrane surface. Composite membrane fabricated with glycol or glycerol as the additive showed very good chemical stability.

  12. Targeted cellular ablation based on the morphology of malignant cells

    PubMed Central

    Ivey, Jill W.; Latouche, Eduardo L.; Sano, Michael B.; Rossmeisl, John H.; Davalos, Rafael V.; Verbridge, Scott S.

    2015-01-01

    Treatment of glioblastoma multiforme (GBM) is especially challenging due to a shortage of methods to preferentially target diffuse infiltrative cells, and therapy-resistant glioma stem cell populations. Here we report a physical treatment method based on electrical disruption of cells, whose action depends strongly on cellular morphology. Interestingly, numerical modeling suggests that while outer lipid bilayer disruption induced by long pulses (~100 μs) is enhanced for larger cells, short pulses (~1 μs) preferentially result in high fields within the cell interior, which scale in magnitude with nucleus size. Because enlarged nuclei represent a reliable indicator of malignancy, this suggested a means of preferentially targeting malignant cells. While we demonstrate killing of both normal and malignant cells using pulsed electric fields (PEFs) to treat spontaneous canine GBM, we proposed that properly tuned PEFs might provide targeted ablation based on nuclear size. Using 3D hydrogel models of normal and malignant brain tissues, which permit high-resolution interrogation during treatment testing, we confirmed that PEFs could be tuned to preferentially kill cancerous cells. Finally, we estimated the nuclear envelope electric potential disruption needed for cell death from PEFs. Our results may be useful in safely targeting the therapy-resistant cell niches that cause recurrence of GBM tumors. PMID:26596248

  13. Targeted cellular ablation based on the morphology of malignant cells.

    PubMed

    Ivey, Jill W; Latouche, Eduardo L; Sano, Michael B; Rossmeisl, John H; Davalos, Rafael V; Verbridge, Scott S

    2015-11-24

    Treatment of glioblastoma multiforme (GBM) is especially challenging due to a shortage of methods to preferentially target diffuse infiltrative cells, and therapy-resistant glioma stem cell populations. Here we report a physical treatment method based on electrical disruption of cells, whose action depends strongly on cellular morphology. Interestingly, numerical modeling suggests that while outer lipid bilayer disruption induced by long pulses (~100 μs) is enhanced for larger cells, short pulses (~1 μs) preferentially result in high fields within the cell interior, which scale in magnitude with nucleus size. Because enlarged nuclei represent a reliable indicator of malignancy, this suggested a means of preferentially targeting malignant cells. While we demonstrate killing of both normal and malignant cells using pulsed electric fields (PEFs) to treat spontaneous canine GBM, we proposed that properly tuned PEFs might provide targeted ablation based on nuclear size. Using 3D hydrogel models of normal and malignant brain tissues, which permit high-resolution interrogation during treatment testing, we confirmed that PEFs could be tuned to preferentially kill cancerous cells. Finally, we estimated the nuclear envelope electric potential disruption needed for cell death from PEFs. Our results may be useful in safely targeting the therapy-resistant cell niches that cause recurrence of GBM tumors.

  14. Targeted cellular ablation based on the morphology of malignant cells

    NASA Astrophysics Data System (ADS)

    Ivey, Jill W.; Latouche, Eduardo L.; Sano, Michael B.; Rossmeisl, John H.; Davalos, Rafael V.; Verbridge, Scott S.

    2015-11-01

    Treatment of glioblastoma multiforme (GBM) is especially challenging due to a shortage of methods to preferentially target diffuse infiltrative cells, and therapy-resistant glioma stem cell populations. Here we report a physical treatment method based on electrical disruption of cells, whose action depends strongly on cellular morphology. Interestingly, numerical modeling suggests that while outer lipid bilayer disruption induced by long pulses (~100 μs) is enhanced for larger cells, short pulses (~1 μs) preferentially result in high fields within the cell interior, which scale in magnitude with nucleus size. Because enlarged nuclei represent a reliable indicator of malignancy, this suggested a means of preferentially targeting malignant cells. While we demonstrate killing of both normal and malignant cells using pulsed electric fields (PEFs) to treat spontaneous canine GBM, we proposed that properly tuned PEFs might provide targeted ablation based on nuclear size. Using 3D hydrogel models of normal and malignant brain tissues, which permit high-resolution interrogation during treatment testing, we confirmed that PEFs could be tuned to preferentially kill cancerous cells. Finally, we estimated the nuclear envelope electric potential disruption needed for cell death from PEFs. Our results may be useful in safely targeting the therapy-resistant cell niches that cause recurrence of GBM tumors.

  15. Changes in cell morphology due to plasma membrane wounding by acoustic cavitation

    PubMed Central

    Schlicher, Robyn K.; Hutcheson, Joshua D.; Radhakrishna, Harish; Apkarian, Robert P.; Prausnitz, Mark R.

    2010-01-01

    Acoustic cavitation-mediated wounding (i.e., sonoporation) has great potential to improve medical and laboratory applications requiring intracellular uptake of exogenous molecules; however, the field lacks detailed understanding of cavitation-induced morphological changes in cells and their relative importance. Here, we present an in-depth study of the effects of acoustic cavitation on cells using electron and confocal microscopy coupled with quantitative flow cytometry. High resolution images of treated cells show that morphologically different types of blebs can occur after wounding conditions caused by ultrasound exposure as well as by mechanical shear and strong laser ablation. In addition, these treatments caused wound-induced non-lytic necrotic death resulting in cell bodies we call wound-derived perikarya (WD-P). However, only cells exposed to acoustic cavitation experienced ejection of intact nuclei and nearly instant lytic necrosis. Quantitative analysis by flow cytometry indicates that wound-derived perikarya are the dominant morphology of nonviable cells, except at the strongest wounding conditions, where nuclear ejection accounts for a significant portion of cell death after ultrasound exposure. PMID:20350691

  16. Effects of a Tantalum Addition on the Morphological and Compositional Evolutions of a Model Ni-AL-Cr Superalloy

    NASA Technical Reports Server (NTRS)

    Booth-Morrison, Christopher; Seidman, David N.; Noebe, Ronald D.

    2008-01-01

    The effects of a 2.0 at.% addition of Ta to a model Ni-Al-Cr superalloy aged at 1073 K are assessed using scanning electron microscopy and atom-probe tomography. The addition of Ta results in appreciable strengthening, and the morphology is found to evolve from a bimodal distribution of spheroidal precipitates, to cuboidal precipitates aligned along the elastically soft <001>-type directions. Tantalum is observed to partition preferentially to the gamma -precipitate phase and decreases the mobility of Ni in the gamma- matrix sufficiently to cause an accumulation of Ni on the gamma-matrix side of the gamma -precipitate/gamma-matrix heterophase interface.

  17. Brain morphology in children with nevoid basal cell carcinoma syndrome.

    PubMed

    Shiohama, Tadashi; Fujii, Katsunori; Miyashita, Toshiyuki; Mizuochi, Hiromi; Uchikawa, Hideki; Shimojo, Naoki

    2017-04-01

    Brain morphology is tightly regulated by diverse signaling pathways. Hedgehog signaling is a candidate pathway considered responsible for regulating brain morphology. Nevoid basal cell carcinoma syndrome (NBCCS), caused by a PTCH1 mutation in the hedgehog signaling pathway, occasionally exhibits macrocephaly and medulloblastoma. Although cerebellar enlargement occurs in ptch1 heterozygous-deficient mice, its impact on human brain development remains unknown. We investigated the brain morphological characteristics of children with NBCCS. We evaluated brain T1-weighted images from nine children with NBCCS and 15 age-matched normal control (NC) children (mean [standard deviation], 12.2 [2.8] vs. 11.6 [2.3] years old). The diameters of the cerebrum, corpus callosum, and brain stem and the cerebellar volume were compared using two-tailed t-tests with Welch's correction. The transverse diameters (150.4 [9.9] vs. 136.0 [5.5] mm, P = 0.002) and longitudinal diameters (165.4 [8.0] vs. 151.3 [8.7] mm, P = 0.0007) of the cerebrum, cross-sectional area of the cerebellar vermis (18.7 [2.6] vs. 11.8 [1.7] cm(2) , P = 0.0001), and total volume of the cerebellar hemispheres (185.1 [13.0] vs. 131.9 [10.4] cm(3) , P = 0.0001) were significantly larger in the children with NBCCS than in NC children. Thinning of the corpus callosum and ventricular enlargement were also confirmed in children with NBCCS. We demonstrate that, on examination of the brain morphology, an increase in the size of the cerebrum, cerebellum, and cerebral ventricles is revealed in children with NBCCS compared to NC children. This suggests that constitutively active hedgehog signaling affects human brain morphology and the PI3K/AKT and RAS/MAPK pathways.

  18. Enhancing Fullerene-Based Solar Cell Lifetimes by Addition of a Fullerene Dumbbell**

    PubMed Central

    Schroeder, Bob C; Li, Zhe; Brady, Michael A; Faria, Gregório Couto; Ashraf, Raja Shahid; Takacs, Christopher J; Cowart, John S; Duong, Duc T; Chiu, Kar Ho; Tan, Ching-Hong; Cabral, João T; Salleo, Alberto; Chabinyc, Michael L; Durrant, James R; McCulloch, Iain

    2014-01-01

    Cost-effective, solution-processable organic photovoltaics (OPV) present an interesting alternative to inorganic silicon-based solar cells. However, one of the major remaining challenges of OPV devices is their lack of long-term operational stability, especially at elevated temperatures. The synthesis of a fullerene dumbbell and its use as an additive in the active layer of a PCDTBT:PCBM-based OPV device is reported. The addition of only 20 % of this novel fullerene not only leads to improved device efficiencies, but more importantly also to a dramatic increase in morphological stability under simulated operating conditions. Dynamic secondary ion mass spectrometry (DSIMS) and TEM are used, amongst other techniques, to elucidate the origins of the improved morphological stability. PMID:25264304

  19. The serotonin receptor 5-HT₇R regulates the morphology and migratory properties of dendritic cells.

    PubMed

    Holst, Katrin; Guseva, Daria; Schindler, Susann; Sixt, Michael; Braun, Armin; Chopra, Himpriya; Pabst, Oliver; Ponimaskin, Evgeni

    2015-08-01

    Dendritic cells are potent antigen-presenting cells endowed with the unique ability to initiate adaptive immune responses upon inflammation. Inflammatory processes are often associated with an increased production of serotonin, which operates by activating specific receptors. However, the functional role of serotonin receptors in regulation of dendritic cell functions is poorly understood. Here, we demonstrate that expression of serotonin receptor 5-HT7 (5-HT7R) as well as its downstream effector Cdc42 is upregulated in dendritic cells upon maturation. Although dendritic cell maturation was independent of 5-HT7R, receptor stimulation affected dendritic cell morphology through Cdc42-mediated signaling. In addition, basal activity of 5-HT7R was required for the proper expression of the chemokine receptor CCR7, which is a key factor that controls dendritic cell migration. Consistent with this, we observed that 5-HT7R enhances chemotactic motility of dendritic cells in vitro by modulating their directionality and migration velocity. Accordingly, migration of dendritic cells in murine colon explants was abolished after pharmacological receptor inhibition. Our results indicate that there is a crucial role for 5-HT7R-Cdc42-mediated signaling in the regulation of dendritic cell morphology and motility, suggesting that 5-HT7R could be a new target for treatment of a variety of inflammatory and immune disorders.

  20. Optimization of molecular organization and nanoscale morphology for high performance low bandgap polymer solar cells

    NASA Astrophysics Data System (ADS)

    He, Ming; Wang, Mengye; Lin, Changjian; Lin, Zhiqun

    2014-03-01

    Rational design and synthesis of low bandgap (LBG) polymers with judiciously tailored HOMO and LUMO levels have emerged as a viable route to high performance polymer solar cells with power conversion efficiencies (PCEs) exceeding 10%. In addition to engineering the energy-level of LBG polymers, the photovoltaic performance of LBG polymer-based solar cells also relies on the device architecture, in particular the fine morphology of the photoactive layer. The nanoscale interpenetrating networks composed of nanostructured donor and acceptor phases are the key to providing a large donor-acceptor interfacial area for maximizing the exciton dissociation and offering a continuous pathway for charge transport. In this Review Article, we summarize recent strategies for tuning the molecular organization and nanoscale morphology toward an enhanced photovoltaic performance of LBG polymer-based solar cells.

  1. Optimization of molecular organization and nanoscale morphology for high performance low bandgap polymer solar cells.

    PubMed

    He, Ming; Wang, Mengye; Lin, Changjian; Lin, Zhiqun

    2014-04-21

    Rational design and synthesis of low bandgap (LBG) polymers with judiciously tailored HOMO and LUMO levels have emerged as a viable route to high performance polymer solar cells with power conversion efficiencies (PCEs) exceeding 10%. In addition to engineering the energy-level of LBG polymers, the photovoltaic performance of LBG polymer-based solar cells also relies on the device architecture, in particular the fine morphology of the photoactive layer. The nanoscale interpenetrating networks composed of nanostructured donor and acceptor phases are the key to providing a large donor-acceptor interfacial area for maximizing the exciton dissociation and offering a continuous pathway for charge transport. In this Review Article, we summarize recent strategies for tuning the molecular organization and nanoscale morphology toward an enhanced photovoltaic performance of LBG polymer-based solar cells.

  2. Morphological properties of mouse retinal ganglion cells during postnatal development.

    PubMed

    Coombs, Julie L; Van Der List, Deborah; Chalupa, Leo M

    2007-08-20

    Quantitative methods were used to assess dendritic stratification and other structural features of developing mouse retinal ganglion cells from birth to after eye opening. Cells were labeled by transgenic expression of yellow fluorescent protein, DiOlistics or diffusion of DiI, and subsequently imaged in three dimensions on a confocal microscope followed by morphometric analysis of 13 different structural properties. At postnatal day 1 (P1), the dendrites of all cells ramified across the vertical extent of the inner plexiform layer (IPL). By P3/4, dendrites were largely confined to different strata of the IPL. The stratification of dendrites initially reflected a retraction of widely ramifying dendritic processes, but for the most part this was due to the subsequent vertical expansion of the IPL. By P8, distinct cell classes could be recognized, although these had not yet attained adult-like properties. The structural features differentiating cell classes were found to follow three different developmental trends. The mean values of one set of morphological parameters were essentially unchanged throughout postnatal development; another set of measures showed a rapid rise with age to adult values; and a third set of measures first increased with age and later decreased, with the regressive events initiated around the time of eye opening. These findings suggest that the morphological development of retinal ganglion cells is regulated by diverse factors operating during different but overlapping time periods. Our results also suggest that dendritic stratification may be more highly specified in the developing mammalian retina than has been previously realized.

  3. Effects of Organic Additives on the Morphology of Various Calcium Phosphates Prepared via Solution and Emulsion Methods

    NASA Astrophysics Data System (ADS)

    Kimura, I.; Wei, T.; Kikushima, Y.; Riman, R.; Akazawa, T.

    2011-10-01

    Dicalcium phosphate anhydrous (DCPA) and dicalcium phosphate dihydrate (DCPD) particles were prepared through the reaction between calcium nitrate and dipotassium hydrogen phosphate in a solution and a multiple emulsion. Organic compounds were added into the phosphate solution with the aim of modifying the morphology. Large parallelogrammic particles of DCPD were obtained with no additive. By adding 2-aminoethanol, the product was changed to rhombic in shape and reduced to one-twentieth in size, and the phase was DCPA. In the multiple emulsion, microspheres composed of DCPA were prepared. They were constructed by flaky, primary particles. The crystalline phase and morphology were affected by the concentrations of surfactants in the oil and outer aqueous phases.

  4. Additional records for Stenosagola newtoni Park & Carlton, 2013 (Staphylinidae: Pselaphinae: Faronitae), with notes on aedeagal morphology

    PubMed Central

    2014-01-01

    Abstract The purpose of this short note is to identify morphospecies sp. 0471 of the Hope River Forest Fragmentation Project. It is Stenosagola newtoni Park & Carlton, 2013. The material listed herein raises the number of published specimen records for Stenosagola newtoni from 2 to 51. All additional 49 specimens are fully winged males, collected in flight intercept traps (FITs), from the South Island of New Zealand. Examination of the new material has resulted in the detection of an error in the original description of Stenosagola newtoni, whereby the mirror image of the aedeagus was inadvertently illustrated. It is not a case of genitalic antisymmetry. PMID:25425940

  5. Additional records for Stenosagolanewtoni Park & Carlton, 2013 (Staphylinidae: Pselaphinae: Faronitae), with notes on aedeagal morphology.

    PubMed

    Thorpe, Stephen E

    2014-01-01

    The purpose of this short note is to identify morphospecies sp. 0471 of the Hope River Forest Fragmentation Project. It is Stenosagolanewtoni Park & Carlton, 2013. The material listed herein raises the number of published specimen records for Stenosagolanewtoni from 2 to 51. All additional 49 specimens are fully winged males, collected in flight intercept traps (FITs), from the South Island of New Zealand. Examination of the new material has resulted in the detection of an error in the original description of Stenosagolanewtoni, whereby the mirror image of the aedeagus was inadvertently illustrated. It is not a case of genitalic antisymmetry.

  6. Laser additive manufacturing of stainless steel micro fuel cells

    NASA Astrophysics Data System (ADS)

    Scotti, Gianmario; Matilainen, Ville; Kanninen, Petri; Piili, Heidi; Salminen, Antti; Kallio, Tanja; Franssila, Sami

    2014-12-01

    This paper introduces laser additive manufacturing as a new method for the fabrication of micro fuel cells: The method opens up the capability of ultrafast prototyping, as the whole device can be produced at once, starting from a digital 3D model. In fact, many different devices can be produced at once, which is useful for the comparison of competing designs. The micro fuel cells are made of stainless steel, so they are very robust, thermally and chemically inert and long-lasting. This enables the researcher to perform a large number of experiments on the same cell without physical or chemical degradation. To demonstrate the validity of our method, we have produced three versions of a micro fuel cell with square pillar flowfield. All three have produced high current and power density, with maximum values of 1.2 A cm-2 for the current and 238 mW cm-2 for power.

  7. Tailoring the morphology of high molecular weight PLLA scaffolds through bioglass addition.

    PubMed

    Barroca, N; Daniel-da-Silva, A L; Vilarinho, P M; Fernandes, M H V

    2010-09-01

    Thermally induced phase separation (TIPS) has proven to be a suitable method for the preparation of porous structures for tissue engineering applications, and particular attention has been paid to increasing the pore size without the use of possible toxic surfactants. Within this context, an alternative method to control the porosity of polymeric scaffolds via the combination with a bioglass is proposed in this work. The addition of a bioactive glass from the 3CaO x P2O5-MgO-SiO2 system enables the porous structure of high molecular weight poly(l-lactic) acid (PLLA) scaffolds prepared by TIPS to be tailored. Bioglass acts as a nucleating catalyst agent of the PLLA matrix, promoting its crystallization, and the glass solubility controls the pore size. A significant increase in the pore size is observed as the bioglass content increases and scaffolds with large pore size (approximately 150 microm) can be prepared. In addition, the bioactive character of the scaffolds is proved by in vitro tests in synthetic plasma. The importance of this approach resides on the combination of the ability to tailor the porosity of polymeric scaffolds via the tunable solubility of bioglasses, without the use of toxic surfactants, leading to a composite structure with suitable properties for bone tissue engineering applications.

  8. Modifications in astrocyte morphology and calcium signaling induced by a brain capillary endothelial cell line.

    PubMed

    Yoder, Elizabeth J

    2002-04-15

    Astrocytes extend specialized endfoot processes to perisynaptic and perivascular regions, and thus are positioned to mediate the bidirectional flow of metabolic, ionic, and other transmissive substances between neurons and the blood stream. While mutual structural and functional interactions between neurons and astrocytes have been documented, less is known about the interactions between astrocytes and cerebrovascular cells. For example, although the ability of astrocytes to induce structural and functional changes in endothelial cells is established, the reciprocity of brain endothelial cells to induce changes in astrocytes is undetermined. This issue is addressed in the present study. Changes in primary cultures of neonatal mouse cortical astrocytes were investigated following their coculture with mouse brain capillary endothelial (bEnd3) cells. The presence of bEnd3 cells altered the morphology of astrocytes by transforming them from confluent monolayers into networks of elongated multicellular columns. These columns did not occur when either bEnd3 cells or astrocytes were cocultured with other cell types, suggesting that astrocytes undergo specific morphological consequences when placed in close proximity to brain endothelial cells. In addition to these structural changes, the pharmacological profile of astrocytes was modified by coculture with bEnd3 cells. Astrocytes in the cocultures showed an increased Ca2+ responsiveness to bradykinin and glutamate, but no change in responsiveness to ATP, as compared to controls. Coculturing the astrocytes with a neuronal cell line resulted in increased responsiveness of the glial responses to glutamate but not to bradykinin. These studies indicate that brain endothelial cells induce changes in astrocyte morphology and pharmacology.

  9. A Morphological identification cell cytotoxicity assay using cytoplasm-localized fluorescent probe (CLFP) to distinguish living and dead cells.

    PubMed

    Lai, Fangfang; Shen, Zhengwei; Wen, Hui; Chen, Jialing; Zhang, Xiang; Lin, Ping; Yin, Dali; Cui, Huaqing; Chen, Xiaoguang

    2017-01-08

    Cell cytotoxicity assays include cell activity assays and morphological identification assays. Currently, all frequently used cytotoxicity assays belong to cell activity assays but suffer from detection limitations. Morphological identification of cell death remains as the gold standard, although the method is difficult to scale up. At present there is no generally accepted morphological identification based cell cytotoxicity assay. In this study, we applied previous developed cell cytoplasm-localized fluorescent probe (CLFP) to display cell morphologies. Under fluorescence microscopy, the fluorescence morphology and intensity of living cells are distinct from dead cells. Based on these characters we extracted the images of living cells from series of samples via computational analysis. Thus, a novel cell morphological identification cytotoxicity assay (CLFP assay) is developed. The performance of the CLFP assay was similar to cell activity assay (MTT assay), but the accuracy of the CLFP assay was superior when measuring the cytotoxicity of active compounds.

  10. A Complex Interaction Between Reduced Reelin Expression and Prenatal Organophosphate Exposure Alters Neuronal Cell Morphology

    PubMed Central

    Mullen, Brian R.; Ross, Brennan; Chou, Joan Wang; Khankan, Rana; Khialeeva, Elvira; Bui, Kimberly

    2016-01-01

    Genetic and environmental factors are both likely to contribute to neurodevelopmental disorders including schizophrenia, autism spectrum disorders, and major depressive disorders. Prior studies from our laboratory and others have demonstrated that the combinatorial effect of two factors—reduced expression of reelin protein and prenatal exposure to the organophosphate pesticide chlorpyrifos oxon—gives rise to acute biochemical effects and to morphological and behavioral phenotypes in adolescent and young adult mice. In the current study, we examine the consequences of these factors on reelin protein expression and neuronal cell morphology in adult mice. While the cell populations that express reelin in the adult brain appear unchanged in location and distribution, the levels of full length and cleaved reelin protein show persistent reductions following prenatal exposure to chlorpyrifos oxon. Cell positioning and organization in the hippocampus and cerebellum are largely normal in animals with either reduced reelin expression or prenatal exposure to chlorpyrifos oxon, but cellular complexity and dendritic spine organization is altered, with a skewed distribution of immature dendritic spines in adult animals. Paradoxically, combinatorial exposure to both factors appears to generate a rescue of the dendritic spine phenotypes, similar to the mitigation of behavioral and morphological changes observed in our prior study. Together, our observations support an interaction between reelin expression and chlorpyrifos oxon exposure that is not simply additive, suggesting a complex interplay between genetic and environmental factors in regulating brain morphology. PMID:27364165

  11. Monitoring cell morphology during necrosis and apoptosis by quantitative phase imaging

    NASA Astrophysics Data System (ADS)

    Mugnano, Martina; Calabuig, Alejandro; Grilli, Simonetta; Miccio, Lisa; Ferraro, Pietro

    2015-05-01

    present a preliminary study on the variation of morphological parameters in case of cell apoptosis induced by exposure to 10 μM cadmium chloride. We employ the same cell line, monitoring the process for 18 hours. In the vast group of environmental pollutants, the toxic heavy metal cadmium is considered a likely candidate as a causative agent of several types of cancers. Widely distributed and used in industry, and with a broad range of target organs and a long half-life (10-30 years) in the human body, this element has been long known for its multiple adverse effects on human health, through occupational or environmental exposure. In apoptosis, we measure cell volume decrease and cell shrinking. Both data of apoptosis and necrosis were analysed by means of a Sigmoidal Statistical Distribution function, which allows several quantitative data to be established, such as swelling and cell death time, flux of intracellular material from inside to outside the cell, initial and final volume versus time. In addition, we can quantitatively study the cytoplasmatic granularity that occurs during necrosis. As a future application, DH could be employed as a non-invasive and label-free method to distinguish between apoptosis and necrosis in terms of morphological parameters.

  12. A Comparison between Growth Morphology of "Eutectic" Cells/Dendrites and Single-Phase Cells/Dendrites

    NASA Technical Reports Server (NTRS)

    Tewari, S. N.; Raj, S. V.; Locci, I. E.

    2003-01-01

    Directionally solidified (DS) intermetallic and ceramic-based eutectic alloys with an in-situ composite microstructure containing finely distributed, long aspect ratio, fiber, or plate reinforcements are being seriously examined for several advanced aero-propulsion applications. In designing these alloys, additional solutes need to be added to the base eutectic composition in order to improve heir high-temperature strength, and provide for adequate toughness and resistance to environmental degradation. Solute addition, however, promotes instability at the planar liquid-solid interface resulting in the formation of two-phase eutectic "colonies." Because morphology of eutectic colonies is very similar to the single-phase cells and dendrites, the stability analysis of Mullins and Sekerka has been extended to describe their formation. Onset of their formation shows a good agreement with this approach; however, unlike the single-phase cells and dendrites, there is limited examination of their growth speed dependence of spacing, morphology, and spatial distribution. The purpose of this study is to compare the growth speed dependence of the morphology, spacing, and spatial distribution of eutectic cells and dendrites with that for the single-phase cells and dendrites.

  13. Alkenyl Carboxylic Acid: Engineering the Nanomorphology in Polymer-Polymer Solar Cells as Solvent Additive.

    PubMed

    Zhang, Yannan; Yuan, Jianyu; Sun, Jianxia; Ding, Guanqun; Han, Lu; Ling, Xufeng; Ma, Wanli

    2017-04-06

    We have investigated a series of commercially available alkenyl carboxylic acids with different alkenyl chain lengths (trans-2-hexenoic acid (CA-6), trans-2-decenoic acid (CA-10), 9-tetradecenoic acid (CA-14)) for use as solvent additives in polymer-polymer non-fullerene solar cells. We systematically investigated their effect on the film absorption, morphology, carrier generation, transport, and recombination in all-polymer solar cells. We revealed that these additives have a significant impact on the aggregation of polymer acceptor, leading to improved phase segregation in the blend film. This in-depth understanding of the additives effect on the nanomorphology in all-polymer solar cell can help further boost the device performance. By using CA-10 with the optimal alkenyl chain length, we achieved fine phase separation, balanced charge transport, and suppressed recombination in all-polymer solar cells. As a result, an optimal power conversion efficiency (PCE) of 5.71% was demonstrated which is over 50% higher than that of the as-cast device (PCE = 3.71%) and slightly higher than that of devices with DIO treatment (PCE = 5.68%). Compared with widely used DIO, these halogen-free alkenyl carboxylic acids have a more sustainable processing as well as better performance, which may make them more promising candidates for use as processing additives in organic non-fullerene solar cells.

  14. Cadmium induces direct morphological changes in mesangial cell culture.

    PubMed

    L'Azou, Béatrice; Dubus, Isabelle; Ohayon-Courtès, Céline; Labouyrie, Jean; Perez, Laurent; Pouvreau, Carole; Juvet, Ludivine; Cambar, Jean

    2002-10-15

    The cadmium produced by industrial and agricultural practice represents a major environmental pollutant which may induce severe damage, especially in the kidney where cadmium accumulates. While cadmium is known to severely impair renal tubular functions, glomerular structures are also potential targets. The present study investigated the effects of cadmium on glomerular mesangial cell cultures after short- and long-term exposures, requiring for each endpoint specific culture conditions. After 30 min exposure to 1 microM CdCl(2), used as non-lethal concentration, 0.14 ng/microg proteins of cadmium was internalized by the cells as evaluated by atomic emision spectrometry and induced a significant, cell surface reduction (8.9+/-1.9%). These morphological changes could be correlated to smooth muscle alpha-actin disorganization, without quantitative change in its protein expression level as evaluated by Western-blot and Northern-blot analysis (SMAmRNA/28sRNA, 1.78 CdCl(2) vs. 1.42 control). For longer exposure times, in complex medium, cadmium uptake was efficient (0.36 ng/microg proteins) and induced changes in the actin cytoskeleton with no loss of cell membrane integrity. This study suggests that cultured mesangial cells provide an alternative model to study the effect of cadmium, and underlines the importance of using well-defined conditions to study further intracellular mechanisms.

  15. Testicular structure and germ cells morphology in salamanders

    PubMed Central

    Uribe, Mari Carmen; Mejía-Roa, Víctor

    2014-01-01

    Testes of salamanders or urodeles are paired elongated organs that are attached to the dorsal wall of the body by a mesorchium. The testes are composed of one or several lobes. Each lobe is morphologically and functionally a similar testicular unit. The lobes of the testis are joined by cords covered by a single peritoneal epithelium and subjacent connective tissue. The cords contain spermatogonia. Spermatogonia associate with Sertoli cells to form spermatocysts or cysts. The spermatogenic cells in a cyst undergo their development through spermatogenesis synchronously. The distribution of cysts displays the cephalo-caudal gradient in respect to the stage of spermatogenesis. The formation of cysts at cephalic end of the testis causes their migration along the lobules to the caudal end. Consequently, the disposition in cephalo-caudal regions of spermatogenesis can be observed in longitudinal sections of the testis. The germ cells are spermatogonia, diploid cells with mitotic activity; primary and second spermatocytes characterized by meiotic divisions that develop haploid spermatids; during spermiogenesis the spermatids differentiate to spermatozoa. During spermiation the cysts open and spermatozoa leave the testicular lobules. After spermiation occurs the development of Leydig cells into glandular tissue. This glandular tissue regressed at the end of the reproductive cycle. PMID:26413406

  16. Cryosurgery as Additional Treatment in Tenosynovial Giant Cell Tumors

    PubMed Central

    Scholte, A.; van der Geest, I. C. M.; Hannink, G.; Schreuder, H. W. B.

    2016-01-01

    Introduction. Tenosynovial giant cell tumors (TGCT) emerge from the synovium and can behave aggressively. Surgical resection is the standard treatment. However, up to half of the patients with diffuse type show recurrences. Several additional treatments have been applied to reduce recurrences; none of these treatments was proven to be superior to surgical resection solely. This article describes the results of additional cryosurgery to surgical resection. Materials and Methods. We retrospectively evaluated 141 TGCT patients, between 1999 and 2007. Twelve patients had additional cryosurgery. The knee (n = 8), hip (n = 2), ankle (n = 1), and elbow (n = 1) were affected. Primary outcome variables were treatment indications, recurrences, and complications. Results. Indications for additional cryosurgery were extended disease, bone involvement, and locations that are difficult to surgically get disease-free such as cruciate ligaments. Five patients had recurrent disease, all of which had prior treatments. None of the primary treated patients had recurrent disease. One patient had a deep infection. Discussion. Cryosurgery may serve as an additional treatment for diffuse TCGT in selected cases. However, because of the small number of patients and the heterogeneous group we could not prove an advantage of additional cryosurgery over surgical resection only. Cryosurgery should be considered for further evaluation in a prospective study. If there is any effect it would be helpful, especially in patients with multiple TGCT recurrences. PMID:28115910

  17. Cell-Substrate Interactions Feedback to Direct Cell Migration along or against Morphological Polarization

    PubMed Central

    Kumar, Girish; Ho, Chia-Chi; Co, Carlos C.

    2015-01-01

    In response to external stimuli, cells polarize morphologically into teardrop shapes prior to moving in the direction of their blunt leading edge through lamellipodia extension and retraction of the rear tip. This textbook description of cell migration implies that the initial polarization sets the direction of cell migration. Using microfabrication techniques to control cell morphologies and the direction of migration without gradients, we demonstrate that after polarization, lamelipodia extension and attachment can feedback to change and even reverse the initial morphological polarization. Cells do indeed migrate faster in the direction of their morphologically polarization. However, feedback from subsequent lamellipodia extension and attachment can be so powerful as to induce cells to reverse and migrate against their initial polarization, albeit at a slower speed. Constitutively active mutants of RhoA show that RhoA stimulates cell motility when cells are guided either along or against their initial polarization. Cdc42 activation and inhibition, which results in loss of directional motility during chemotaxis, only reduces the speed of migration without altering the directionality of migration on the micropatterns. These results reveal significant differences between substrate directed cell migration and that induced by chemotactic gradients. PMID:26186588

  18. Heme-oxygenase-1 implications in cell morphology and the adhesive behavior of prostate cancer cells

    PubMed Central

    Gueron, Geraldine; Giudice, Jimena; Valacco, Pia; Paez, Alejandra; Elguero, Belen; Toscani, Martin; Jaworski, Felipe; Leskow, Federico Coluccio; Cotignola, Javier; Marti, Marcelo; Binaghi, Maria; Navone, Nora; Vazquez, Elba

    2014-01-01

    Prostate cancer (PCa) is the second leading cause of cancer death in men. Although previous studies in PCa have focused on cell adherens junctions (AJs), key players in metastasis, they have left the molecular mechanisms unexplored. Inflammation and the involvement of reactive oxygen species (ROS) are critical in the regulation of cell adhesion and the integrity of the epithelium. Heme oxygenase-1 (HO-1) counteracts oxidative and inflammatory damage. Here, we investigated whether HO-1 is implicated in the adhesive and morphological properties of tumor cells. Genes differentially regulated by HO-1 were enriched for cell motility and adhesion biological processes. HO-1 induction, increased E-cadherin and β-catenin levels. Immunofluorescence analyses showed a striking remodeling of E-cadherin/β-catenin based AJs under HO-1 modulation. Interestingly, the enhanced levels of E-cadherin and β-catenin coincided with a markedly change in cell morphology. To further our analysis we sought to identify HO-1 binding proteins that might participate in the regulation of cell morphology. A proteomics approach identified Muskelin, as a novel HO-1 partner, strongly implicated in cell morphology regulation. These results define a novel role for HO-1 in modulating the architecture of cell-cell interactions, favoring a less aggressive phenotype and further supporting its anti-tumoral function in PCa. PMID:24961479

  19. Chronic Replication Problems Impact Cell Morphology and Adhesion of DNA Ligase I Defective Cells.

    PubMed

    Cremaschi, Paolo; Oliverio, Matteo; Leva, Valentina; Bione, Silvia; Carriero, Roberta; Mazzucco, Giulia; Palamidessi, Andrea; Scita, Giorgio; Biamonti, Giuseppe; Montecucco, Alessandra

    2015-01-01

    Moderate DNA damage resulting from metabolic activities or sub-lethal doses of exogenous insults may eventually lead to cancer onset. Human 46BR.1G1 cells bear a mutation in replicative DNA ligase I (LigI) which results in low levels of replication-dependent DNA damage. This replication stress elicits a constitutive phosphorylation of the ataxia telangiectasia mutated (ATM) checkpoint kinase that fails to arrest cell cycle progression or to activate apoptosis or cell senescence. Stable transfection of wild type LigI, as in 7A3 cells, prevents DNA damage and ATM activation. Here we show that parental 46BR.1G1 and 7A3 cells differ in important features such as cell morphology, adhesion and migration. Comparison of gene expression profiles in the two cell lines detects Bio-Functional categories consistent with the morphological and migration properties of LigI deficient cells. Interestingly, ATM inhibition makes 46BR.1G1 more similar to 7A3 cells for what concerns morphology, adhesion and expression of cell-cell adhesion receptors. These observations extend the influence of the DNA damage response checkpoint pathways and unveil a role for ATM kinase activity in modulating cell biology parameters relevant to cancer progression.

  20. Putative role of border cells in generating spontaneous morphological activity within Kölliker's organ.

    PubMed

    Dayaratne, M W Nishani; Vlajkovic, Srdjan M; Lipski, Janusz; Thorne, Peter R

    2015-12-01

    Kölliker's organ is a transient epithelial structure, comprising a major part of the organ of Corti during pre-hearing stages of development. The auditory system is spontaneously active during development, which serves to retain and refine neural connections. Kölliker's organ is considered a key candidate for generating such spontaneous activity, most likely through purinergic (P2 receptor) signalling and inner hair cell (IHC) activation. Associated with the spontaneous neural activity, ATP released locally by epithelial cells induces rhythmic morphological changes within Kölliker's organ, the purpose of which is not understood. These changes are accompanied by a shift in cellular refractive index, allowing optical detection of this activity in real-time. Using this principle, we investigated the origin of spontaneous morphological activity within Kölliker's organ. Apical turns of Wistar rat cochleae (P9-11) were dissected, and the purinergic involvement was studied following acute tissue exposure to a P2 receptor agonist (ATPγS) and antagonist (suramin). ATPγS induced a sustained darkening throughout Kölliker's organ, reversed by suramin. This effect was most pronounced in the region closest to the inner hair cells, which also displayed the highest frequency of intrinsic morphological events. Additionally, suramin alone induced swelling of this region, suggesting a tight regulation of cell volume by ATP-mediated mechanisms. Histological analysis of cochlear tissues demonstrates the most profound volume changes in the border cell region immediately adjacent to the IHCs. Together, these results underline the role of purinergic signalling in initiating morphological events within Kölliker's organ, and suggest a key involvement of border cells surrounding IHCs in regulating this spontaneous activity.

  1. One-step, low-temperature deposited perovskite solar cell utilizing small molecule additive

    NASA Astrophysics Data System (ADS)

    Chen, Chun-Chao; Hong, Zirou; Li, Gang; Chen, Qi; Zhou, Huanping; Yang, Yang

    2015-01-01

    In the current study, the perovskite absorber (CH3NH3PbI3) is processed via one-step deposition employing the small molecule additive, BmPyPhB, which can be dissolved in dimethylformamide along with precursors. Here, 1,3-Bis[3,5-di(pyridin-3-yl)phenyl]benzene (BmPyPhB) functions as the morphology controller to introduce an intermediate phase during perovskite film growth, which allows well-defined and precrystallized domains formed before the annealing treatment. Furthermore, a chloroform solvent wash procedure is applied afterward to remove BmPyPhB from perovskite without damaging the predetermined morphology. Thus, postannealing as low as 100°C for 5 min can achieve the optimal power conversion efficiency of 8% in a planar-structured inverted solar cell.

  2. Effect of gelatinization and additives on morphology and thermal behavior of corn starch/PVA blend films.

    PubMed

    Luo, Xuegang; Li, Jiwei; Lin, Xiaoyan

    2012-11-06

    The blend films of ungelatinized and gelatinized starch/polyvinyl alcohol (PVA) were prepared with a solution casting method by the introduction of additives (glycerol/urea) or not. The phase morphologies and thermal behaviors of the blends were carefully analyzed. A droplet phase was observed in the blends containing ungelatinized starch and a laminated phase was observed in the blends containing gelatinized starch. For both ungelatinized and gelatinized starch/PVA blends, the melting temperature (T(m)) (210-230 °C) of PVA was detected, and the T(m) of gelatinized starch/PVA blends was higher than that of the ungelatinized starch/PVA blends. Blend films containing 16.8 wt% of glycerol or urea exhibited a decreased T(m). The introduction of additives (glycerol or urea) reduced the decomposition onset temperature of the blend films. These various morphologies and thermal behaviors could be attributed to the different hydrogen bonding interaction characteristics between starch and polyvinyl alcohol at different conditions.

  3. Device and morphological engineering of organic solar cells for enhanced charge transport and photovoltaic performance

    NASA Astrophysics Data System (ADS)

    Adhikari, Nirmal; Khatiwada, Devendra; Dubey, Ashish; Qiao, Qiquan

    2015-01-01

    Conjugated polymers are potential materials for photovoltaic applications due to their high absorption coefficient, mechanical flexibility, and solution-based processing for low-cost solar cells. A bulk heterojunction (BHJ) structure made of donor-acceptor composite can lead to high charge transfer and power conversion efficiency. Active layer morphology is a key factor for device performance. Film formation processes (e.g., spray-coating, spin-coating, and dip-coating), post-treatment (e.g., annealing and UV ozone treatment), and use of additives are typically used to engineer the morphology, which optimizes physical properties, such as molecular configuration, miscibility, lateral and vertical phase separation. We will review electronic donor-acceptor interactions in conjugated polymer composites, the effect of processing parameters and morphology on solar cell performance, and charge carrier transport in polymer solar cells. This review provides the basis for selection of different processing conditions for optimized nanomorphology of active layers and reduced bimolecular recombination to enhance open-circuit voltage, short-circuit current density, and fill factor of BHJ solar cells.

  4. Cytopathic Changes in Rat Microglial Cells Induced by Pathogenic Acanthamoeba culbertsoni: Morphology and Cytokine Release

    PubMed Central

    Shin, Ho-Joon; Cho, Myung-Soo; Jung, Suk-Yul; Kim, Hyung-Il; Park, Sun; Seo, Jang-Hoon; Yoo, Jung-Chil; Im, Kyung-Il

    2001-01-01

    To determine whether pathogenic Acanthamoeba culbertsoni trophozoites and lysate can induce cytopathic changes in primary-culture microglial cells, morphological changes were observed by transmission electron microscopy (TEM). In addition, the secretion of two kinds of cytokines, tumor necrosis factor alpha (TNF-α) and interleukin-1β (IL-1β), from microglial cells was observed. Trophozoites of pathogenic A. culbertsoni made contact with microglial cells and produced digipodia. TEM revealed that microglial cells cocultured with amoebic trophozoites underwent a necrotic process, accompanied by lysis of the cell membrane. TEM of microglial cells cocultured with amoebic lysate showed that the membranes of the small cytoplasmic vacuoles as well as the cell membrane were lysed. The amounts of TNF-α secreted from microglial cells cocultured with A. culbertsoni trophozoites or lysate increased at 6 h of incubation. The amounts of IL-1β secreted from microglial cells cocultured with A. culbertsoni trophozoites at 6 h of incubation was similar to those secreted from the control group, but the amounts decreased during cultivation with A. culbertsoni lysate. These results suggest that pathogenic A. culbertsoni induces the cytopathic effects in primary-culture rat microglial cells, with the effects characterized by necrosis of microglial cells and changes in levels of secretion of TNF-α and IL-1β from microglial cells. PMID:11427438

  5. Quantification of Dynamic Morphological Drug Responses in 3D Organotypic Cell Cultures by Automated Image Analysis

    PubMed Central

    Härmä, Ville; Schukov, Hannu-Pekka; Happonen, Antti; Ahonen, Ilmari; Virtanen, Johannes; Siitari, Harri; Åkerfelt, Malin; Lötjönen, Jyrki; Nees, Matthias

    2014-01-01

    Glandular epithelial cells differentiate into complex multicellular or acinar structures, when embedded in three-dimensional (3D) extracellular matrix. The spectrum of different multicellular morphologies formed in 3D is a sensitive indicator for the differentiation potential of normal, non-transformed cells compared to different stages of malignant progression. In addition, single cells or cell aggregates may actively invade the matrix, utilizing epithelial, mesenchymal or mixed modes of motility. Dynamic phenotypic changes involved in 3D tumor cell invasion are sensitive to specific small-molecule inhibitors that target the actin cytoskeleton. We have used a panel of inhibitors to demonstrate the power of automated image analysis as a phenotypic or morphometric readout in cell-based assays. We introduce a streamlined stand-alone software solution that supports large-scale high-content screens, based on complex and organotypic cultures. AMIDA (Automated Morphometric Image Data Analysis) allows quantitative measurements of large numbers of images and structures, with a multitude of different spheroid shapes, sizes, and textures. AMIDA supports an automated workflow, and can be combined with quality control and statistical tools for data interpretation and visualization. We have used a representative panel of 12 prostate and breast cancer lines that display a broad spectrum of different spheroid morphologies and modes of invasion, challenged by a library of 19 direct or indirect modulators of the actin cytoskeleton which induce systematic changes in spheroid morphology and differentiation versus invasion. These results were independently validated by 2D proliferation, apoptosis and cell motility assays. We identified three drugs that primarily attenuated the invasion and formation of invasive processes in 3D, without affecting proliferation or apoptosis. Two of these compounds block Rac signalling, one affects cellular cAMP/cGMP accumulation. Our approach supports

  6. Morphologic and phenotypic changes of human neuroblastoma cells in culture induced by cytosine arabinoside

    SciTech Connect

    Ponzoni, M.; Lanciotti, M.; Melodia, A.; Casalaro, A.; Cornaglia-Ferraris, P. )

    1989-03-01

    The effects of cytosine-arabinoside (ARA-C) on the growth and phenotypic expression of a new human neuroblastoma (NB) cell line (GI-ME-N) have been extensively tested. Low doses of ARA-C allowing more than 90% cell viability induce morphological differentiation and growth inhibition. Differentiated cells were larger and flattened with elongated dendritic processes; such cells appeared within 48 hours after a dose of ARA-C as low as 0.1 {mu}g/ml. The new morphological aspect reached the maximum expression after 5-6 days of culture being independent from the addition of extra drug to the culture. A decrease in ({sup 3}H)thymidine incorporation was also observed within 24 hours and the cell growth was completely inhibited on the sixth day. Moreover, ARA-C strongly inhibited anchorage-independent growth in soft agar assay. Membrane immunofluorescence showed several dramatic changes in NB-specific antigen expression after 5 days of treatment with ARA-C. At the same time ARA-C also modulated cytoskeletal proteins and slightly increased catecholamine expression. These findings suggest that noncytotoxic doses of ARA-C do promote the differentiation of GI-ME-N neuroblastoma cells associated with reduced expression of the malignant phenotype.

  7. A new live-cell reporter strategy to simultaneously monitor mitochondrial biogenesis and morphology.

    PubMed

    Hodneland Nilsson, Linn Iren; Nitschke Pettersen, Ina Katrine; Nikolaisen, Julie; Micklem, David; Avsnes Dale, Hege; Vatne Røsland, Gro; Lorens, James; Tronstad, Karl Johan

    2015-11-24

    Changes in mitochondrial amount and shape are intimately linked to maintenance of cell homeostasis via adaptation of vital functions. Here, we developed a new live-cell reporter strategy to simultaneously monitor mitochondrial biogenesis and morphology. This was achieved by making a genetic reporter construct where a master regulator of mitochondrial biogenesis, nuclear respiratory factor 1 (NRF-1), controls expression of mitochondria targeted green fluorescent protein (mitoGFP). HeLa cells with the reporter construct demonstrated inducible expression of mitoGFP upon activation of AMP-dependent protein kinase (AMPK) with AICAR. We established stable reporter cells where the mitoGFP reporter activity corresponded with mitochondrial biogenesis both in magnitude and kinetics, as confirmed by biochemical markers and confocal microscopy. Quantitative 3D image analysis confirmed accordant increase in mitochondrial biomass, in addition to filament/network promoting and protecting effects on mitochondrial morphology, after treatment with AICAR. The level of mitoGFP reversed upon removal of AICAR, in parallel with decrease in mtDNA. In summary, we here present a new GFP-based genetic reporter strategy to study mitochondrial regulation and dynamics in living cells. This combinatorial reporter concept can readily be transferred to other cell models and contexts to address specific physiological mechanisms.

  8. [Morphological features of papillary thyroid carcinoma with a focal tall-cell component].

    PubMed

    Abrosimov, A Iu; Kozhushnaia, S M

    2012-01-01

    The morphological features of papillary thyroid macro- and microcarcinomas of classical structure with the focal presence or absence of a tall-cell component were comparatively studied. Histological specimens of 55 neoplasms were examined in 53 patients. A trend was seen for the higher rate of regional metastasis in a group of tall-cell tumors. Additional studies of groups of patients matched for sex, age, and extrathyroid tumor extension are required to make a final conclusion on the metastatic potential and prognostic features of tumors with a tall-cell component. To solve this task, it is expedient to separate neoplasms with a focal tall-cell component from the bulk of classical papillary carcinomas.

  9. Addition of P3HT-grafted Silica nanoparticles improves bulk-heterojunction morphology in P3HT-PCBM blends

    NASA Astrophysics Data System (ADS)

    Garg, Mohit; Padmanabhan, Venkat

    2016-09-01

    We present molecular dynamics simulations of a ternary blend of P3HT, PCBM and P3HT-grafted silica nanoparticles (SiNP) for applications in polymer-based solar cells. Using coarse-grained models, we study the effect of SiNP on the spatial arrangement of PCBM in P3HT. Our results suggest that addition of SiNP not only alters the morphology of PCBM clusters but also improves the crystallinity of P3HT. We exploit the property of grafted SiNP to self-assemble into a variety of anisotropic structures and the tendency of PCBM to preferentially adhere to SiNP surface, due to favorable interactions, to achieve morphologies with desirable characteristics for the active layer, including domain size, crystallinity of P3HT, and elimination of isolated islands of PCBM. As the concentration of SiNP increases, the number of isolated PCBM molecules decreases, which in turn improves the crystallinity of P3HT domains. We also observe that by tuning the grafting parameters of SiNP, it is possible to achieve structures ranging from cylindrical to sheets to highly interconnected network of strings. The changes brought about by addition of SiNP shows a promising potential to improve the performance of these materials when used as active layers in organic photovoltaics.

  10. Addition of P3HT-grafted Silica nanoparticles improves bulk-heterojunction morphology in P3HT-PCBM blends

    PubMed Central

    Garg, Mohit; Padmanabhan, Venkat

    2016-01-01

    We present molecular dynamics simulations of a ternary blend of P3HT, PCBM and P3HT-grafted silica nanoparticles (SiNP) for applications in polymer-based solar cells. Using coarse-grained models, we study the effect of SiNP on the spatial arrangement of PCBM in P3HT. Our results suggest that addition of SiNP not only alters the morphology of PCBM clusters but also improves the crystallinity of P3HT. We exploit the property of grafted SiNP to self-assemble into a variety of anisotropic structures and the tendency of PCBM to preferentially adhere to SiNP surface, due to favorable interactions, to achieve morphologies with desirable characteristics for the active layer, including domain size, crystallinity of P3HT, and elimination of isolated islands of PCBM. As the concentration of SiNP increases, the number of isolated PCBM molecules decreases, which in turn improves the crystallinity of P3HT domains. We also observe that by tuning the grafting parameters of SiNP, it is possible to achieve structures ranging from cylindrical to sheets to highly interconnected network of strings. The changes brought about by addition of SiNP shows a promising potential to improve the performance of these materials when used as active layers in organic photovoltaics. PMID:27628895

  11. Lithium Dinitramide as an Additive in Lithium Power Cells

    NASA Technical Reports Server (NTRS)

    Gorkovenko, Alexander A.

    2007-01-01

    Lithium dinitramide, LiN(NO2)2 has shown promise as an additive to nonaqueous electrolytes in rechargeable and non-rechargeable lithium-ion-based electrochemical power cells. Such non-aqueous electrolytes consist of lithium salts dissolved in mixtures of organic ethers, esters, carbonates, or acetals. The benefits of adding lithium dinitramide (which is also a lithium salt) include lower irreversible loss of capacity on the first charge/discharge cycle, higher cycle life, lower self-discharge, greater flexibility in selection of electrolyte solvents, and greater charge capacity. The need for a suitable electrolyte additive arises as follows: The metallic lithium in the anode of a lithium-ion-based power cell is so highly reactive that in addition to the desired main electrochemical reaction, it engages in side reactions that cause formation of resistive films and dendrites, which degrade performance as quantified in terms of charge capacity, cycle life, shelf life, first-cycle irreversible capacity loss, specific power, and specific energy. The incidence of side reactions can be reduced through the formation of a solid-electrolyte interface (SEI) a thin film that prevents direct contact between the lithium anode material and the electrolyte. Ideally, an SEI should chemically protect the anode and the electrolyte from each other while exhibiting high conductivity for lithium ions and little or no conductivity for electrons. A suitable additive can act as an SEI promoter. Heretofore, most SEI promotion was thought to derive from organic molecules in electrolyte solutions. In contrast, lithium dinitramide is inorganic. Dinitramide compounds are known as oxidizers in rocket-fuel chemistry and until now, were not known as SEI promoters in battery chemistry. Although the exact reason for the improvement afforded by the addition of lithium dinitramide is not clear, it has been hypothesized that lithium dinitramide competes with other electrolyte constituents to react with

  12. Trichodorus petrusalberti n. sp. (Nematoda: Trichodoridae) from Rice with Additional Notes on the Morphology of T. sanniae and T. rinae

    PubMed Central

    De Waele, D.

    1988-01-01

    A new species in the family Trichodoridae, from the rhizosphere of rice (Oryza sativa L.) in Northern Natal, South Africa, is described and illustrated. Trichodorus petrusalberti n. sp. resembles T. taylori De Waele, Mancini, Roca, and Lamberti, 1982, T. hooperi Loof, 1973, and T. complexus Rahman, Jairajpuri, and Ahmad, 1985, from which it is distinguished by the shape of the spicules. It is distinguished from the former two species by the nonthickened terminal cuticle in the males and by the shape and sclerotization of the vulval-vaginal region in lateral view in the females. Additional morphological details are given for T. sanniae Vermeulen and Heyns, 1985 and T. rinae Vermeulen and Heyns, 1985. PMID:19290188

  13. Additive to regulate the perovskite crystal film growth in planar heterojunction solar cells

    SciTech Connect

    Song, Xin; Sun, Po; Chen, Zhi-Kuan E-mail: iamzkchen@njtech.edu.cn; Wang, Weiwei; Ma, Wanli E-mail: iamzkchen@njtech.edu.cn

    2015-01-19

    We reported a planar heterojunction perovskite solar cell fabricated from MAPbI{sub 3−x}Cl{sub x} perovskite precursor solution containing 1-chloronaphthalene (CN) additive. The MAPbI{sub 3−x}Cl{sub x} perovskite films have been characterized by UV-vis, SEM, XRD, and steady-state photoluminescence (PL). UV-vis absorption spectra measurement shows that the absorbance of the film with CN additive is significantly higher than the pristine film and the absorption peak is red shift by 30 nm, indicating the perovskite film with additive possessing better crystal structures. In-situ XRD study of the perovskite films with additive demonstrated intense diffraction peaks from MAPbI{sub 3−x}Cl{sub x} perovskite crystal planes of (110), (220), and (330). SEM images of the films with additive indicated the films were more smooth and homogenous with fewer pin-holes and voids and better surface coverage than the pristine films. These results implied that the additive CN is beneficial to regulate the crystallization transformation kinetics of perovskite to form high quality crystal films. The steady-state PL measurement suggested that the films with additive contained less charge traps and defects. The planar heterojunction perovskite solar cells fabricated from perovskite precursor solution containing CN additive demonstrated 30% enhancement in performance compared to the devices with pristine films. The improvement in device efficiency is mainly attributed to the good crystal structures, more homogenous film morphology, and also fewer trap centers and defects in the films with the additive.

  14. Spontaneous activity of morphologically identified ganglion cells in the developing ferret retina.

    PubMed

    Liets, Lauren C; Olshausen, Bruno A; Wang, Guo-Yong; Chalupa, Leo M

    2003-08-13

    Whole-cell patch-clamp recordings were made from morphologically identified ganglion cells in the intact retina of developing ferrets. As early as 3 d after birth, all ganglion cells exhibited bursts of spontaneous activity, with the interval between bursts gradually decreasing with maturity. By 2 weeks after birth, ganglion cells could be morphologically differentiated into three major classes (alpha, beta, and gamma), and at this time each cell class was characterized by a distinct pattern of spontaneous activity. Dual patch-clamp recordings from pairs of neighboring cells revealed that cells of all morphological classes burst in a coordinated manner, regardless of cell type. These observations suggest that a common mechanism underlies the bursting patterns exhibited by all ganglion cell classes, and that class-specific firing patterns emerge coincident with retinal ganglion cell morphological differentiation.

  15. A morphological classification of retinal ganglion cells in the Japanese catshark Scyliorhinus torazame.

    PubMed

    Muguruma, Kaori; Stell, William K; Yamamoto, Naoyuki

    2014-01-01

    Retinal ganglion cells (GCs) in the Japanese catshark Scyliorhinus torazame were labeled retrogradely with biotinylated dextran amine (BDA3000). First the labeled cells were classified into 5 morphological types (types I-III: small GCs; types IV and V: large GCs) according to the size of the soma and the dendritic arborization pattern as seen in retinal wholemounts. Type I cells were stellate, with dendrites radiating in different directions. Type II cells had bipolar dendritic trees, with 2 primary dendrites extending in opposite directions. Type III cells had a single thick primary dendrite. Type IV cells were stellate, with dendrites covering a large area centered on the cell body. Type V cells were asymmetric, with most dendrites extending opposite to the axon as a large, fan-shaped dendritic field. Subsequently a wholemount was cross-sectioned, and we classified cells further into multiple subtypes according to the level of dendritic arborization within the inner plexiform layer. The present results suggest the existence of many types of GCs in elasmobranchs in addition to the 3 types of large GCs that have been characterized previously. Some of the newly described GC subtypes in the catshark retina appear to be similar to some of those reported in actinopterygians.

  16. Mesoporous Titania Powders: The Role of Precursors, Ligand Addition and Calcination Rate on Their Morphology, Crystalline Structure and Photocatalytic Activity

    PubMed Central

    Masolo, Elisabetta; Meloni, Manuela; Garroni, Sebastiano; Mulas, Gabriele; Enzo, Stefano; Baró, Maria Dolors; Rossinyol, Emma; Rzeszutek, Agnieszka; Herrmann-Geppert, Iris; Pilo, Maria

    2014-01-01

    We evaluate the influence of the use of different titania precursors, calcination rate, and ligand addition on the morphology, texture and phase content of synthesized mesoporous titania samples, parameters which, in turn, can play a key role in titania photocatalytic performances. The powders, obtained through the evaporation-induced self-assembly method, are characterized by means of ex situ X-Ray Powder Diffraction (XRPD) measurements, N2 physisorption isotherms and transmission electron microscopy. The precursors are selected basing on two different approaches: the acid-base pair, using TiCl4 and Ti(OBu)4, and a more classic route with Ti(OiPr)4 and HCl. For both precursors, different specimens were prepared by resorting to different calcination rates and with and without the addition of acetylacetone, that creates coordinated species with lower hydrolysis rates, and with different calcination rates. Each sample was employed as photoanode and tested in the water splitting reaction by recording I-V curves and comparing the results with commercial P25 powders. The complex data framework suggests that a narrow pore size distribution, due to the use of acetylacetone, plays a major role in the photoactivity, leading to a current density value higher than that of P25. PMID:28344237

  17. Pyrrolidinone derivatives as processing additives for solution processed organic solar cells

    NASA Astrophysics Data System (ADS)

    Vongsaysy, Uyxing; Pavageau, Bertrand; Servant, Laurent; Aziz, Hany

    2014-10-01

    Processing additives are widely used to increase the efficiency of solution processed organic solar cells. We use the Hansen solubility parameters (HSPs) to investigate novel processing additives. The HSPs predict pyrrolidinone derivatives to be efficient processing additives for OSC systems based on poly(3-hexylthiophene)/[6,6]-phenyl-C61- butyric acid methyl ester (P3HT/PCBM). Two pyrrolidinone derivatives are identified: 1-methyl-2-pyrrolidinone and 1- benzyl-2-pyrrolidinone. The processing additives are introduced with various concentrations in the formulation of P3HT and PCBM solution. The electrical characterizations show that the two processing additives significantly increase the short circuit current and thus the power conversion efficiency of the OSCs. The results thus highlight HSPs as an effective and relatively straightforward tool that can be employed to optimize OSC morphology from a theoretical standpoint. Such a tool will be invaluable for identifying additives for novel high efficiency polymer species as they are synthesized, and thus to streamline the device fabrication and device optimization process.

  18. Live-cell imaging study of mitochondrial morphology in mammalian cells exposed to X-rays.

    PubMed

    Noguchi, M; Kanari, Y; Yokoya, A; Narita, A; Fujii, K

    2015-09-01

    Morphological changes in mitochondria induced by X-irradiation in normal murine mammary gland cells were studied with a live-cell microscopic imaging technique. Mitochondria were visualised by staining with a specific fluorescent probe in the cells, which express fluorescent ubiquitination-based cell-cycle indicator 2 (Fucci2) probes to visualise cell cycle. In unirradiated cells, the number of cells with fragmented mitochondria was about 20 % of the total cells through observation period (96 h). In irradiated cells, the population with fragmented mitochondria significantly increased depending on the absorbed dose. Particularly, for 8 Gy irradiation, the accumulation of fragmentation persists even in the cells whose cell cycle came to a stand (80 % in G1 (G0-like) phase). The fraction reached to a maximum at 96 h after irradiation. The kinetics of the fraction with fragmented mitochondria was similar to that for cells in S/G2/M phase (20 %) through the observation period (120 h). The evidences show that, in irradiated cells, some signals are continually released from a nucleus or cytoplasm even in the G0-like cells to operate some sort of protein machineries involved in mitochondrial fission. It is inferred that this delayed mitochondrial fragmentation is strongly related to their dysfunction, and hence might modulate radiobiological effects such as mutation or cell death.

  19. Charge dynamics in alkanedithiols-additives in P3HT:PCBM bulk heterojunction solar cells

    NASA Astrophysics Data System (ADS)

    Solanki, Ankur; Wu, Bo; Lam, Yeng Ming; Sum, Tze Chien

    2014-10-01

    Addition of a small fraction of high boiling point solvent into the host of donor/acceptor blend is one the best approach to control the morphology in order to enhance the power conversion efficiency of organic bulk heterojunction (BHJ) solar cell devices. Herein, we focus on the effect of two thiol-based additives (1,6-hexanedithiol (HDT) and 1,5-pentanedithiol (PDT)) on the charge dynamics of P3HT:PCBM blend system, studied by transient absorption spectroscopy (TAS) and correlated with the solar cell device performance. TAS reveals a more efficient charge generation and polaron formation in the systems with additives as compared to those without (NA systems), at the onset which persists up to few microseconds. The recombination dynamics also exhibits the reduced recombination losses on adding these additives in this system; however, there is marginal change of recombination dynamics in PDT added system with the control. These charge dynamics were validated using the analytical model proposed in our previous work and also correlated with improved device performance (ηNA = 0.9%, ηHDT = 2.7%, ηPDT = 1.6%).

  20. Consecutive Morphology Controlling Operations for Highly Reproducible Mesostructured Perovskite Solar Cells.

    PubMed

    Wu, Yongzhen; Chen, Wei; Yue, Youfeng; Liu, Jian; Bi, Enbing; Yang, Xudong; Islam, Ashraful; Han, Liyuan

    2015-09-23

    Perovskite solar cells have shown high photovoltaic performance but suffer from low reproducibility, which is mainly caused by low uniformity of the active perovskite layer in the devices. The nonuniform perovskites further limit the fabrication of large size solar cells. In this work, we control the morphology of CH3NH3PbI3 on a mesoporous TiO2 substrate by employing consecutive antisolvent dripping and solvent-vapor fumigation during spin coating of the precursor solution. The solvent-vapor treatment is found to enhance the perovskite pore filling and increase the uniformity of CH3NH3PbI3 in the porous scaffold layer but slightly decrease the uniformity of the perovskite capping layer. An additional antisolvent dripping is employed to recover the uniform perovskite capping layer. Such consecutive morphology controlling operations lead to highly uniform perovskite in both porous and capping layers. By using the optimized perovskite deposition procedure, the reproducibility of mesostructured solar cells was greatly improved such that a total of 40 devices showed an average efficiency of 15.3% with a very small standard deviation of 0.32. Moreover, a high efficiency of 14.9% was achieved on a large-size cell with a working area of 1.02 cm(2).

  1. Morphological Spectrum of Basal Cell Carcinoma in Southern Karnataka

    PubMed Central

    Lobo, Flora Dorothy; Naik, Ramdas; Khadilkar, Urmila Niranjan; Kini, Hema; Kini, Ullal Anand

    2016-01-01

    Introduction Basal Cell Carcinoma (BCC) is the most common skin cancer worldwide, which appears over sun-exposed skin as slow-growing, locally invasive lesion that rarely metastasizes. Many phenotypic presentations are possible. BCCs are more common in males and tend to occur in older people. Majority is found on the head and neck. Many histopathological subtypes have been defined including nodular, micronodular, cystic, superficial, pigmented, adenoid, infiltrating, sclerosing, keratotic, infundibulocystic, metatypical, basosquamous and fibroepitheliomatous. Mixed patterns are common. Aim The aim was to study morphological spectrum of BCC in a tertiary care hospital in southern Karnataka. Materials and Methods This was a retrospective analysis of 100 cases of BCCs reported in the Department of Pathology over a 9-year period from 2006 to 2014. Results The mean age of presentation was 62 years. There was slight female preponderance (56%). The most common location was face (65%) and the most common presentation was ulceration (45%). Of the 100 BCCs, 50% were nodular, 13% infiltrating, 6% basosquamous, 4% superficial, 3% keratotic, 3% multinodular and 1% mixed. Conclusion BCC, besides being the commonest cutaneous cancer, is also known for its numerous histological patterns which are shown to have prognostic implications. This study reveals the frequency of the various histological patterns of BCC in southern Karnataka, where it has been rarely studied before. PMID:27504291

  2. The effect of solvent additives on morphology and excited-state dynamics in PCPDTBT:PCBM photovoltaic blends.

    PubMed

    Etzold, Fabian; Howard, Ian A; Forler, Nina; Cho, Don M; Meister, Michael; Mangold, Hannah; Shu, Jie; Hansen, Michael Ryan; Müllen, Klaus; Laquai, Frédéric

    2012-06-27

    The dependence of the thin film morphology and excited-state dynamics for the low-bandgap donor-acceptor copolymer poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']-dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT) in pristine films and in blends (1:2) with [6,6]-phenyl-C(61)-butyric acid methyl ester (PCBM) on the use of the solvent additive 1,8-octanedithiol (ODT) is studied by solid-state nuclear magnetic resonance (NMR) spectroscopy and broadband visible and near-infrared pump-probe transient absorption spectroscopy (TAS) covering a spectral range from 500-2000 nm. The latter allows monitoring of the dynamics of excitons, bound interfacial charge-transfer (CT) states, and free charge carriers over a time range from femto- to microseconds. The broadband pump-probe experiments reveal that excitons are not only generated in the polymer but also in PCBM-rich domains. Depending on the morphology controlled by the use of solvent additives, polymer excitons undergo mainly ultrafast dissociation (<100 fs) in blends prepared without ODT or diffusion-limited dissociation in samples prepared with ODT. Excitons generated in PCBM diffuse slowly to the interface in both samples and undergo dissociation on a time scale of several tens of picoseconds up to hundreds of picoseconds. In both samples a significant fraction of the excitons creates strongly bound interfacial CT states, which exhibit subnanosecond geminate recombination. The total internal quantum efficiency loss due to geminate recombination is estimated to be 50% in samples prepared without ODT and is found to be reduced to 30% with ODT, indicating that more free charges are generated in samples prepared with solvent additives. In samples prepared with ODT, the free charges exhibit clear intensity-dependent recombination dynamics, which can be modeled by Langevin-type recombination with a bimolecular recombination coefficient of 6.3 × 10(-11) cm(3) s(-1). In samples prepared without ODT, an

  3. Control of morphology and nanostructure of copper and cobalt oxalates: Effect of complexing ions, polymeric additives and molecular weight

    NASA Astrophysics Data System (ADS)

    Bowen, Paul; Pujol, Ollivier; Jongen, Nathalie; Lemaître, Jacques; Fink, Alke; Stadleman, Pierre; Hofmann, Heinrich

    2010-11-01

    Precipitated oxalates are often nanostructured and can be used as precursors for nanostructured oxides for different applications. The modification of the particle shape and nanostructures of both copper and cobalt oxalates has been demonstrated using polymeric additives or complexing counter-ions. In the case of cobalt oxalate the characteristic elongated rod particle shape (axial ratio of 10) can be modified by using polymethymethacrylate (PMMA) to produce particles with lower axial ratios of 2, through cubes all the way to platelets (axial ratio 0.2). The PMMA inhibits the growth of the particles along the [101] direction more and more strongly as the concentration of the polymer increases. The crystallite size from XRD line broadening is not modified by the PMMA indicating that the PMMA does not influence the nucleation and growth but modifies the aggregation kinetics. Copper oxalates precipitated in the presence of different cellulose derived polymers with different molecular weights and functional groups (methyl and propyl) showed sensitivity to both molecular weight and functional group. Higher molecular weights did not influence the copper oxalate particle shape, whereas methyl cellulose gave elongated particles and propyl celluloses gave platelet like particles. Copper oxalate precipitated in the presence of acetate counter ions gave platelets with an axial ratio of 0.15 compared to the cushion-like morphology (axial ratio 0.5). The primary crystallites were more elongated along the [001] direction in the presence of acetate, modifying the proportion of the hydrophobic and hydrophilic surfaces and hence influencing the aggregation kinetics and particle shape. The copper and cobalt oxalate particle formation seems to be dominated by the primary particle aggregation with the different additives interacting specifically with different crystallographic faces of the primary particles. By tuning this interaction particles with different shapes and substructures

  4. Effect of an iodine-containing additive on the composition, structure, and morphology of chemically deposited lead selenide films

    NASA Astrophysics Data System (ADS)

    Smirnova, Z. I.; Bakanov, V. M.; Maskaeva, L. N.; Markov, V. F.; Voronin, V. I.

    2014-12-01

    The effect of an ammonium iodide additive on the elemental and phase compositions, structural parameters, and surface morphology of lead selenide films synthesized by chemical deposition from aqueous solutions has been studied using X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray analysis. It has been established that the obtained PbSe films have a multiphase structure. The iodine content of the films is directly proportional to the NH4I concentration in the reaction mixture and increases linearly with an increase in this concentration to 0.25 mol/L. No individual iodine-containing phases have been detected in the film structure. However, the introduction of iodine leads to an increase in the PbSe phase lattice parameter from ˜6.11 to ˜6.16 Å and to a decrease in the crystal grain size to ˜ 20 nm. It has been found that there is a correlation between the grain size, lattice parameter, and ammonium iodide concentration in the reaction mixture, which can be explained by changes in the film growth mechanism at the initial growth steps.

  5. Surface modification of additive manufactured Ti6Al4V alloy with Ag nanoparticles: wettability and surface morphology study

    NASA Astrophysics Data System (ADS)

    Chudinova, E.; Surmeneva, M.; Koptioug, A.; Sharonova, A.; Loza, K.; Surmenev, R.

    2016-02-01

    In this work, the use of electrophoretic deposition to modify the surface of Ti6Al4V alloy fabricated via additive manufacturing technology is reported. Poly(vinylpyrrolidone) (PVP)-stabilized silver nanoparticles (AgNPs) had a spherical shape with a diameter of the metallic core of 100±20 nm and ζ -potential -15 mV. The AgNPs- coated Ti6Al4V alloy was studied in respect with its chemical composition and surface morphology, water contact angle, hysteresis, and surface free energy. The results of SEM microphotography analysis showed that the AgNPs were homogeneously distributed over the surface. Hysteresis and water contact angle measurements revealed the effect of the deposited AgNPs layer, namely an increased water contact angle and decreased contact angle hysteresis. However, the average water contact angle was 125° for PVP-stabilized-AgNPs-coated surface, whereas ethylene glycol gave the average contact angle of 17°. A higher surface energy is observed for AgNPs-coated Ti6Al4V surface (70.17 mN/m) compared with the uncoated surface (49.07 mN/m).

  6. Cytotoxicity and morphological effects induced by carvacrol and thymol on the human cell line Caco-2.

    PubMed

    Llana-Ruiz-Cabello, María; Gutiérrez-Praena, Daniel; Pichardo, Silvia; Moreno, F Javier; Bermúdez, José María; Aucejo, Susana; Cameán, Ana María

    2014-02-01

    Essential oils used as additives in the food industry due to its flavour, antimicrobial and antioxidant properties. Therefore, human can be exposed orally to these compounds through the ingestion of foods. In this sense, the present work aims to assess toxicological effects of oregano essential oil on the digestive tract. In concrete, the cytotoxic effects of two components of the oregano essential oils, carvacrol and thymol, and their mixture, on the intestinal cells line Caco-2 after 24 and 48 h of exposure are studied. The basal cytotoxicity endpoints assayed (total protein content, neutral red uptake and the tetrazolium salt reduction) and the annexin/propidium iodide staining indicated that carvacrol and the mixture carvacrol/thymol induced toxic effects. Moreover, a morphological study was performed in order to determine the ultrastructural cellular damages caused by these substances. The main morphological alterations were vacuolated cytoplasm, altered organelles and finally cell death. In addition, although no cytotoxic effects were recorded for thymol at any concentration and time of exposure, ultrastructural changes evidenced cellular damage such as lipid degeneration, mitochondrial damage, nucleolar segregation and apoptosis.

  7. Cartography of cell morphology in tomato pericarp at the fruit scale.

    PubMed

    Legland, D; Devaux, M-F; Bouchet, B; Guillon, F; Lahaye, M

    2012-07-01

    In fleshy fruits, the variability of cell morphology at the fruit scale is largely unknown. It presents both a huge variability and a high level of organization. Better knowledge of cell morphology heterogeneity within the fruit is necessary to understand fruit development, to model fruit mechanical behaviour, or to investigate variations of physico-chemical measurements. A generic approach is proposed to build cartographies of cell morphology at the fruit scale, which depict regions corresponding to different cell morphologies. The approach is based on: (1) sampling the whole fruit at known positions; (2) imaging and quantifying local cell morphology; (3) pooling measurements to take biological variability into account and (4) projecting results in a morphology model of the whole fruit. The result is a synthetic representation of cell morphology variations within the whole fruit. The method was applied to the characterization of cell morphology in tomato pericarp. Two different imaging scales that provided complementary descriptions were used: 3D confocal microscopy and macroscopy. The approach is generic and can be adapted to other fruits or other products.

  8. Physical Explanation of Coupled Cell-Cell Rotational Behavior and Interfacial Morphology: A Particle Dynamics Model

    PubMed Central

    Leong, Fong Yew

    2013-01-01

    Previous studies have reported persistent rotational behavior between adherent cell-cell pairs cultured on micropatterned substrates, and this rotation is often accompanied by a sigmoidal deflection of the cell-cell interface. Interestingly, the cell-cell rotation runs in the opposite reference frame from what could be expected of single cell locomotion. Specifically, the rotation of the cell pair consists of each individual cell protruding from the inwardly regressive arm of the cell-cell interface, and retracting from the other outwardly protrusive arm. To this author’s knowledge, the cause of this elusive behavior has not yet been clarified. Here, we propose a physical model based on particle dynamics, accounting for actomyosin forcing, viscous dissipation, and cortical tension. The results show that a correlation in actomyosin force vectors leads to both persistent rotational behavior and interfacial deflection in a simulated cell cluster. Significantly, the model, without any artificial cues, spontaneously and consistently reproduces the same rotational reference frame as experimentally observed. Further analyses show that the interfacial deflection depends predominantly on cortical tension, whereas the cluster rotation depends predominantly on actomyosin forcing. Together, these results corroborate the hypothesis that both rotational and morphological phenomena are, in fact, physically coupled by an intracellular torque of a common origin. PMID:24268142

  9. Physical explanation of coupled cell-cell rotational behavior and interfacial morphology: a particle dynamics model.

    PubMed

    Leong, Fong Yew

    2013-11-19

    Previous studies have reported persistent rotational behavior between adherent cell-cell pairs cultured on micropatterned substrates, and this rotation is often accompanied by a sigmoidal deflection of the cell-cell interface. Interestingly, the cell-cell rotation runs in the opposite reference frame from what could be expected of single cell locomotion. Specifically, the rotation of the cell pair consists of each individual cell protruding from the inwardly regressive arm of the cell-cell interface, and retracting from the other outwardly protrusive arm. To this author's knowledge, the cause of this elusive behavior has not yet been clarified. Here, we propose a physical model based on particle dynamics, accounting for actomyosin forcing, viscous dissipation, and cortical tension. The results show that a correlation in actomyosin force vectors leads to both persistent rotational behavior and interfacial deflection in a simulated cell cluster. Significantly, the model, without any artificial cues, spontaneously and consistently reproduces the same rotational reference frame as experimentally observed. Further analyses show that the interfacial deflection depends predominantly on cortical tension, whereas the cluster rotation depends predominantly on actomyosin forcing. Together, these results corroborate the hypothesis that both rotational and morphological phenomena are, in fact, physically coupled by an intracellular torque of a common origin.

  10. Morphological and histological characteristics of mammary dysplasias occurring in cell dissociation-derived murine mammary outgrowths

    SciTech Connect

    Ethier, S.P.; Adams, L.M.; Ullrich, R.L.

    1984-10-01

    The morphological and histological characteristics of ductal dysplasias that were observed in mammary outgrowths derived from monodispersed mammary cells of carcinogen-treated mice are described. Mammary outgrowths were derived by injecting either 10(4) or 10(5) enzymatically dissociated mammary cells, obtained from control or carcinogen-treated BALB/c mice, into gland-free mammary fat pads of syngeneic hosts. The mammary dysplasias observed varied considerably in morphological and histological characteristics. The majority of the lesions were ductal in origin and were associated with epithelial hyperplasia which ranged from mild hyperplasia, in which only a few extra layers of epithelium were present, to severe hyperplasia, in which the ducts and end buds were occluded and distended with epithelial cells. In addition, papillary and lobular lesions were observed which were also associated with varying degrees of hyperplasia. The range of mammary dysplasias observed in these outgrowths closely resembles that of lesions associated with the pathogenesis of mammary carcinoma in mice, rats, and humans.

  11. Cell proliferation and hair cell addition in the ear of the goldfish, Carassius auratus

    NASA Technical Reports Server (NTRS)

    Lanford, P. J.; Presson, J. C.; Popper, A. N.

    1996-01-01

    Cell proliferation and hair cell addition have not been studied in the ears of otophysan fish, a group of species who have specialized hearing capabilities. In this study we used the mitotic S-phase marker bromodeoxyuridine (BrdU) to identify proliferating cells in the ear of one otophysan species, Carassius auratus (the goldfish). Animals were sacrificed at 3 h or 5 days postinjection with BrdU and processed for immunocytochemistry. The results of the study show that cell proliferation occurs in all of the otic endorgans and results in the addition of new hair cells. BrdU-labeled cells were distributed throughout all epithelia, including the primary auditory endorgan (saccule), where hair cell phenotypes vary considerably along the rostrocaudal axis. This study lays the groundwork for our transmission electron microscopy study of proliferative cells in the goldfish ear (Presson et al., Hearing Research 100 (1996) 10-20) as well as future studies of hair cell development in this species. The ability to predict, based on epithelial location, the future phenotype of developing hair cells in the saccule of the goldfish make that endorgan a particularly powerful model system for the investigation of early hair cell differentiation.

  12. Effects of dinitrotoluenes on morphological cell transformation and intercellular communication in Syrian hamster embryo cells.

    PubMed

    Holen, I; Mikalsen, S O; Sanner, T

    1990-01-01

    The effects of four isomers of dinitrotoluene (DNT) and technical DNT (a mixture of DNT isomers and other compounds, with 2,4-DNT as the major constituent) were studied in two short-term in vitro assays. None of the isomers or technical DNT induced an increase in morphological transformation of Syrian hamster embryo (SHE) cells. Four DNT metabolites (2,4-diaminotoluene, 2-amino-4-nitrotoluene, 2-amino-6-nitrotoluene, and 2,4-dinitobenzoic acid), representing different stages in reduction or oxidation of DNT isomers, were also negative for induction of morphological transformation. The DNT isomers were tested in an intercellular communication assay based on dye transfer. 2,4-DNT, 2,6-DNT, and technical DNT inhibited intercellular communication in the SHE cell line BPNi at toxic concentrations. This may be reminiscent of in vivo data showing promoting activity of these compound. 2,3-DNT and 3,4-DNT did not inhibit communication.

  13. Morphological cell transformation of Syrian hamster embryo (SHE) cells by the cyanotoxin, cylindrospermopsin.

    PubMed

    Maire, M-A; Bazin, E; Fessard, V; Rast, C; Humpage, A R; Vasseur, P

    2010-06-15

    Cylindrospermopsin (CYN) is a cyanotoxin which has been implicated in human intoxication and animal mortality. Genotoxic activity of this hepatotoxin is known but its carcinogenic activity remains to be elucidated. In this work, CYN was assessed for its cell-transforming activity using the Syrian hamster embryo (SHE) cell transformation assay. This in vitro assay is used to evaluate the carcinogenic potential of chemical, physical and biological agents in SHE cells, which are primary, normal, diploid, genetically stable and capable of metabolic activation. We demonstrated that CYN induced a significant increase in morphological cell transformation in SHE cells following a 7-day continuous treatment in the range of non-cytotoxic concentrations 1 x 10(-7)-1 x 10(-2) ng/mL.

  14. KLP6: a newly identified kinesin that regulates the morphology and transport of mitochondria in neuronal cells.

    PubMed

    Tanaka, Kousuke; Sugiura, Yoshimi; Ichishita, Ryohei; Mihara, Katsuyoshi; Oka, Toshihiko

    2011-07-15

    Mitochondria utilize diverse cytoskeleton-based mechanisms to control their functions and morphology. Here, we report a role for kinesin-like protein KLP6, a newly identified member of the kinesin family, in mitochondrial morphology and dynamics. An RNA interference screen using Caenorhabditis elegans led us to identify a C. elegans KLP-6 involved in maintaining mitochondrial morphology. We cloned a cDNA coding for a rat homolog of C. elegans KLP-6, which is an uncharacterized kinesin in vertebrates. A rat KLP6 mutant protein lacking the motor domain induced changes in mitochondrial morphology and significantly decreased mitochondrial motility in HeLa cells, but did not affect the morphology of other organelles. In addition, the KLP6 mutant inhibited transport of mitochondria during anterograde movement in differentiated neuro 2a cells. To date, two kinesins, KIF1Bα and kinesin heavy chain (KHC; also known as KIF5) have been shown to be involved in the distribution of mitochondria in neurons. Expression of the kinesin heavy chain/KIF5 mutant prevented mitochondria from entering into neurites, whereas both the KLP6 and KIF1Bα mutants decreased mitochondrial transport in axonal neurites. Furthermore, both KLP6 and KIF1Bα bind to KBP, a KIF1-binding protein required for axonal outgrowth and mitochondrial distribution. Thus, KLP6 is a newly identified kinesin family member that regulates mitochondrial morphology and transport.

  15. Interfacial properties of cell culture media with cell-protecting additives.

    PubMed

    Michaels, J D; Nowak, J E; Mallik, A K; Koczo, K; Wasan, D T; Papoutsakis, E T

    1995-08-20

    In an effort to identify key rheological properties that contribute to cell protection against shear damage, we have measured surface shear and dilatationai viscosities, dynamic surface tension, foaminess, and foam stability for media containing cell-protecting additives. In a companion article,(18) we found that cell-to-bubble attachment was decreased in media containing Methocel, Pluronic F68, or polyvinyl alcohol (PVA). In medium containing polyethylene glycol (PEG) or potyvinyl-pyrrolidone (PVP), attachment was increased. PEG, PVP, serum (FBS), and serum albumin (BSA) increased the surface viscosity of the air/medium surface (thus, producing a more rigid interface), whereas F68 and PVA lowered it greatly. Foaming experiments showed that Methocel, PEG, PVA, and F68 decreased the foam half-life while FBS, BSA, and PVP were foam stabilizers. Interestingly, the foam stability of CHO cell suspensions decreased significantly for cell concentrations higher than ca. 2 x 10(6) cells/mL. Nonviable CHO cells reduced foam stability further. Dynamic surface tension values of the media tested were found significantly differentfrom their static surface tension values. The interfacial properties measured and the results presented in the companion study suggest that the additives that lower dynamic surface tension the most (Methocel, F68, and PVA) correlate well with reduced cell-to-bubble attachment, and thus, cell protection. Reduced dynamic surface tension with these additives implies faster surfactant adsorption, mobile interfaces, lower surface viscosity, and foam destabilization. Because PEG and PVP resulted in increased cell-to-bubble attachment and had different interfacial properties, a different mechanism (compared with Methocel, PVP, and F68) is apparently responsible for their protective effect. Finally, cell protection offered by FBS and BSA is attributed to the foam stabilization properties provided by these additives. (c) 1995 John Wiley & Sons Inc.

  16. Low hydrostatic head electrolyte addition to fuel cell stacks

    DOEpatents

    Kothmann, Richard E.

    1983-01-01

    A fuel cell and system for supply electrolyte, as well as fuel and an oxidant to a fuel cell stack having at least two fuel cells, each of the cells having a pair of spaced electrodes and a matrix sandwiched therebetween, fuel and oxidant paths associated with a bipolar plate separating each pair of adjacent fuel cells and an electrolyte fill path for adding electrolyte to the cells and wetting said matrices. Electrolyte is flowed through the fuel cell stack in a back and forth fashion in a path in each cell substantially parallel to one face of opposite faces of the bipolar plate exposed to one of the electrodes and the matrices to produce an overall head uniformly between cells due to frictional pressure drop in the path for each cell free of a large hydrostatic head to thereby avoid flooding of the electrodes. The bipolar plate is provided with channels forming paths for the flow of the fuel and oxidant on opposite faces thereof, and the fuel and the oxidant are flowed along a first side of the bipolar plate and a second side of the bipolar plate through channels formed into the opposite faces of the bipolar plate, the fuel flowing through channels formed into one of the opposite faces and the oxidant flowing through channels formed into the other of the opposite faces.

  17. Notch regulates cell fate and dendrite morphology of newborn neurons in the postnatal dentate gyrus

    PubMed Central

    Breunig, Joshua J.; Silbereis, John; Vaccarino, Flora M.; Šestan, Nenad; Rakic, Pasko

    2007-01-01

    The lifelong addition of neurons to the hippocampus is a remarkable form of structural plasticity, yet the molecular controls over proliferation, neuronal fate determination, survival, and maturation are poorly understood. Expression of Notch1 was found to change dynamically depending on the differentiation state of neural precursor cells. Through the use of inducible gain- and loss-of-function of Notch1 mice we show that this membrane receptor is essential to these distinct processes. We found in vivo that activated Notch1 overexpression induces proliferation, whereas γ-secretase inhibition or genetic ablation of Notch1 promotes cell cycle exit, indicating that the level of activated Notch1 regulates the magnitude of neurogenesis from postnatal progenitor cells. Abrogation of Notch signaling in vivo or in vitro leads to a transition from neural stem or precursor cells to transit-amplifying cells or neurons. Further, genetic Notch1 manipulation modulates survival and dendritic morphology of newborn granule cells. These results provide evidence for the expansive prevalence of Notch signaling in hippocampal morphogenesis and plasticity, suggesting that Notch1 could be a target of diverse traumatic and environmental modulators of adult neurogenesis. PMID:18077357

  18. Aminothiol WR-1065 protects endothelial cell morphology against alterations induced by lipopolysaccharide.

    PubMed

    Podolski, J L; Mooteri, S N; Drab-Weiss, E A; Onoda, J M; Saclarides, T J; Rubin, D B

    1998-12-01

    In septic patients, lipopolysaccharide (LPS) damages the vascular endothelium, which manifests as tissue edema and impaired healing. This pathology occurs when LPS distorts endothelial cell morphology partly by generating free radicals. A radioprotector that scavenges free radicals, the aminothiol WR-1065 ([N-2-mercaptoethyl]-1-3-diaminopropane) was found in a prior study to normalize the morphology of irradiated endothelial cells (Mooteri SN, Podolski JL, Drab EA, et al: Radiat Res 145:217-224, 1996). The aim of this study was to determine whether WR-1065 also normalized endothelial cell morphology following exposure to LPS. For this aim, portions of bovine aortic endothelial cell cultures were denuded and exposed to LPS at 1 ng/mL. After 30 min, the apical membrane expressed increased integrin receptor to fibronectin, alpha5beta1. After 5 h, the morphology of the cells at the leading edge was distorted, and cell-cell contact was lessened. Also, filamentous actin-containing stress fibers were dissipated; however, filamentous actin content per cell was unchanged. Treatment with 2 mM WR-1065 for 2 h prior to LPS exposure attenuated the increased expression of alpha5beta1 and promoted cell-cell contact in the migrating endothelial cells. WR-1065 also promoted the retention of stress fibers and actin cytoskeletal shape in cells treated with LPS. Thus, LPS distorted endothelial cell morphology after increasing apical membrane expression of alpha5beta1 and dissipating stress fibers, effects prevented by WR-1065.

  19. Improved performance by morphology control via fullerenes in PBDT-TBT-alkoBT based organic solar cells

    SciTech Connect

    Khatiwada, Devendra; Venkatesan, Swaminathan; Chen, QIliang; Chen, Jihua; Adhikari, Nirmal; Dubey, Ashish; Mitul, Abu Farzan; Mohammed, Lal; Qiao, Qiquan

    2015-01-01

    In this work, we report improved performance by controlling morphology using different fullerene derivatives in poly{2-octyldodecyloxy-benzo[1,2-b;3,4-b]dithiophene-alt-5,6-bis(dodecyloxy)-4,7- di(thieno[3,2-b]thiophen-2-yl)-benzo[c][1,2,5]thiadiazole} (PBDT-TBT-alkoBT) based organic solar cells. PC60BM and PC70BM fullerenes were used to investigate the characteristic change in morphology and device performance. Fullerene affects device efficiency by changing active layer morphology. PC70BM with broader absorption than PC60BM resulted in reduced device performance which was elucidated by the intermixed granular morphology separating each larger grain in the PC70BM/polymer composite layer which created higher density of traps. However after adding additive 1,8-diiodooctane (DIO), the fibrous morphology was observed due to reduced solubility of polymer and increased solubility of PC70BM in chloroform. The fibrous morphology improved charge transport leading to increase in overall device performance. Atomic force microscopies (AFM), photo induced charge extraction by linearly increasing voltage (photo-CELIV), and Kelvin prove force microscope (KPFM) were used to investigate nanoscale morphology of active layer with different fullerene derivatives. For PC60BM based active layer, AFM images revealed dense fibrous morphology and more distinct fibrous morphology was observed by adding DIO. The PC70BM based active layer only exhibited intermixed granular morphology instead of fibrous morphology observed in PC60BM based active layer. However, addition of DIO in PC70BM based active layer led to fibrous morphology. When additive DIO was not used, a wider distribution of surface potential was observed for PC70BM than PC60BM based active layer by KPFM measurements, indicating 2 polymer and fullerene domains are separated. When DIO was used, narrower distribution of surface potential for both PC70

  20. Improved performance by morphology control via fullerenes in PBDT-TBT-alkoBT based organic solar cells

    DOE PAGES

    Khatiwada, Devendra; Venkatesan, Swaminathan; Chen, QIliang; ...

    2015-01-01

    In this work, we report improved performance by controlling morphology using different fullerene derivatives in poly{2-octyldodecyloxy-benzo[1,2-b;3,4-b]dithiophene-alt-5,6-bis(dodecyloxy)-4,7- di(thieno[3,2-b]thiophen-2-yl)-benzo[c][1,2,5]thiadiazole} (PBDT-TBT-alkoBT) based organic solar cells. PC60BM and PC70BM fullerenes were used to investigate the characteristic change in morphology and device performance. Fullerene affects device efficiency by changing active layer morphology. PC70BM with broader absorption than PC60BM resulted in reduced device performance which was elucidated by the intermixed granular morphology separating each larger grain in the PC70BM/polymer composite layer which created higher density of traps. However after adding additive 1,8-diiodooctane (DIO), the fibrous morphology was observed due to reduced solubility of polymer and increasedmore » solubility of PC70BM in chloroform. The fibrous morphology improved charge transport leading to increase in overall device performance. Atomic force microscopies (AFM), photo induced charge extraction by linearly increasing voltage (photo-CELIV), and Kelvin prove force microscope (KPFM) were used to investigate nanoscale morphology of active layer with different fullerene derivatives. For PC60BM based active layer, AFM images revealed dense fibrous morphology and more distinct fibrous morphology was observed by adding DIO. The PC70BM based active layer only exhibited intermixed granular morphology instead of fibrous morphology observed in PC60BM based active layer. However, addition of DIO in PC70BM based active layer led to fibrous morphology. When additive DIO was not used, a wider distribution of surface potential was observed for PC70BM than PC60BM based active layer by KPFM measurements, indicating 2 polymer and fullerene domains are separated. When DIO was used, narrower distribution of surface potential for both PC70BM and PC60BM based active layers was observed. Photo-CELIV experiment

  1. Additives Effects on Crystal Morphology of Dihydroxylammonium 5,5ʹ-Bistetrazole-1,1ʹ-diolate by Molecular Dynamics Simulations

    NASA Astrophysics Data System (ADS)

    Xiong, Shu-Ling; Chen, Shu-Sen; Jin, Shao-Hua; Li, Li-Jie

    2016-10-01

    Dihydroxylammonium 5,5‧-bistetrazole-1,1‧-diolate (TKX-50) is a newly synthesized explosive with excellent comprehensive properties: high energy storage, low impact sensitivity, and low toxicity. To understand and improve the crystal morphology of TKX-50, we reported the polymer consistent force field to simulate the crystal morphology of TKX-50 by growth morphology (GM) method. We then used this force field in molecular dynamics (MD) simulations to predict the influences of additives on crystal facets of TKX-50. The calculated results indicate that ethanol, ethylene glycol, and acetic acid are more favorable to the spheroidization of TKX-50, which provides a theoretical support for the additive selection of crystalline system. Furthermore, we added the selected additives in the recrystallization system of TKX-50. The recrystallized samples possessed a small aspect ratio and were close to spherical in shape, which indicates that the experimental results are consistent with the simulated results.

  2. Ovarian Cancer Cell Line Panel (OCCP): Clinical Importance of In Vitro Morphological Subtypes

    PubMed Central

    Beaufort, Corine M.; Helmijr, Jean C. A.; Piskorz, Anna M.; Hoogstraat, Marlous; Ruigrok-Ritstier, Kirsten; Besselink, Nicolle; Murtaza, Muhammed; van IJcken, Wilfred F. J.; Heine, Anouk A. J.; Smid, Marcel; Koudijs, Marco J.; Brenton, James D.; Berns, Els M. J. J.; Helleman, Jozien

    2014-01-01

    Epithelial ovarian cancer is a highly heterogeneous disease and remains the most lethal gynaecological malignancy in the Western world. Therapeutic approaches need to account for inter-patient and intra-tumoural heterogeneity and detailed characterization of in vitro models representing the different histological and molecular ovarian cancer subtypes is critical to enable reliable preclinical testing. There are approximately 100 publicly available ovarian cancer cell lines but their cellular and molecular characteristics are largely undescribed. We have characterized 39 ovarian cancer cell lines under uniform conditions for growth characteristics, mRNA/microRNA expression, exon sequencing, drug response for clinically-relevant therapeutics and collated all available information on the original clinical features and site of origin. We tested for statistical associations between the cellular and molecular features of the lines and clinical features. Of the 39 ovarian cancer cell lines, 14 were assigned as high-grade serous, four serous-type, one low-grade serous and 20 non-serous type. Three morphological subtypes: Epithelial (n = 21), Round (n = 7) and Spindle (n = 12) were identified that showed distinct biological and molecular characteristics, including overexpression of cell movement and migration-associated genes in the Spindle subtype. Comparison with the original clinical data showed association of the spindle-like tumours with metastasis, advanced stage, suboptimal debulking and poor prognosis. In addition, the expression profiles of Spindle, Round and Epithelial morphologies clustered with the previously described C1-stromal, C5-mesenchymal and C4 ovarian subtype expression profiles respectively. Comprehensive profiling of 39 ovarian cancer cell lines under controlled, uniform conditions demonstrates clinically relevant cellular and genomic characteristics. This data provides a rational basis for selecting models to develop specific treatment

  3. Light scatter characteristics of blast cells in acute myeloid leukaemia: association with morphology and immunophenotype.

    PubMed Central

    Vidriales, M B; Orfao, A; López-Berges, M C; González, M; López-Macedo, A; García, M A; Galende, J; San Miguel, J F

    1995-01-01

    AIMS--To analyse the forward scatter/side scatter (FSC/SSC) distribution of acute myeloblastic leukaemia (AML) blast cells in order to assess whether it correlates with their morphology, immunophenotype, and clinical and biological disease characteristics. METHODS--FSC/SSC patterns were established upon taking into account the localisation of the residual T lymphocytes in the FSC/SSC dot plot as an internal biological standard. One hundred and seventy one newly diagnosed AML patients were analysed and five different FSC/SSC patterns were established. These five patterns could be grouped into two major categories taking into account the FSC/SSC distribution of normal cells in a bone marrow aspirate: immature patterns (1 and 2) and mature patterns (3, 4, and 5). These FSC/SSC patterns were correlated with different clinical and biological characteristics of AML patients. RESULTS--No significant associations were detected in relation to the clinical and haematological disease characteristics and the prognosis of these patients. By contrast there was a significant correlation between the FSC/SSC pattern of the AML blast cells and the FAB classification. An increased reactivity for the antigens associated with myeloid differentiation such as CD13, CD33, CD11b, CD15, CD14, CD4, CD56, and/or CD16 was detected among cases showing a mature FSC/SSC pattern (3, 4, and 5), both in the whole series and even within each of the FAB AML subtypes. By contrast, the reactivity for the CD34 precursor cell associated antigen was higher among those cases displaying an immature FSC/SSC pattern, this being observed even within each FAB subgroup. CONCLUSIONS--The FSC/SSC pattern distribution of AML blast cells not only provides an additional objective and reproductible system for the classification of these leukaemias but it may also represent a connection between the FAB morphological groups and the immunophenotypic classification of AML patients. Images PMID:7629293

  4. Changes in morphology, cell wall composition and soluble proteome in Rhodobacter sphaeroides cells exposed to chromate.

    PubMed

    Italiano, Francesca; Rinalducci, Sara; Agostiano, Angela; Zolla, Lello; De Leo, Francesca; Ceci, Luigi R; Trotta, Massimo

    2012-10-01

    The response of the carotenoidless Rhodobacter sphaeroides mutant R26 to chromate stress under photosynthetic conditions is investigated by biochemical and spectroscopic measurements, proteomic analysis and cell imaging. Cell cultures were found able to reduce chromate within 3-4 days. Chromate induces marked changes in the cellular dimension and morphology, as revealed by atomic force microscopy, along with compositional changes in the cell wall revealed by infrared spectroscopy. These effects are accompanied by significant changes in the level of several proteins: 15 proteins were found up-regulated and 15 down-regulated. The protein content found in chromate exposed cells is in good agreement with the biochemical, spectroscopic and microscopic results. Moreover at the present stage no specific chromate-reductase could be found in the soluble proteome, indicating that detoxification of the pollutant proceeds via aspecific reductants.

  5. Polymer Solar Cells: Understanding Solvent Interactions and Morphology, and Strategies for Efficiency Improvements

    NASA Astrophysics Data System (ADS)

    Chang, Lilian

    Organic solar cells have the potential to be unrivaled in terms of processing cost, speed, and simplicity. The simplest of such devices consists of a single bulk-heterojunction (BHJ) active layer, in which the electron donor (conjugated polymer) and electron acceptor (fullerene) are deposited from a common solvent. The performance of BHJ solar cells is strongly correlated with the nanoscale structure of the active layer. Various processing techniques have been explored to improve the nanoscale morphology of the BHJ layer, e.g. by varying the casting solvent, thermal annealing, solvent annealing, and solvent additives. An understanding of the role of residual solvent in the BHJ layer is imperative in order to develop strategies for morphology stabilization and preserve the longevity of the device. This work highlights the effect of residual solvents on acceptor, (6,6)-phenyl-C61-butyric acid methyl ester (PCBM) diffusion and ultimately the stability of the morphology. We first show that solvent is retained within the BHJ film despite prolonged heat treatment, leading to extensive phase separation between poly(3-hexylthiophene) (P3HT) and PCBM. We then show that the addition of a small volume fraction of nitrobenzene to the casting solution inhibits the diffusion of PCBM in the film and improves the fill factor of the BHJ device without further tempering. Other commonly used additives for morphology improvement were also investigated, i.e. 1,8-diiodooctane and 1-chloronaphthalene. We show that the choice of solvent additives has direct implications on morphological evolution, i.e. P3HT:PCBM BHJ films processed with a small amount of 1,8-diiodooctane or 1-chloronaphthalene have more crystalline PCBM domains compared to crystalline P3HT domains, while the opposite is true for films cast with nitrobenzene additive and films cast purely from chlorobenzene. The BHJ film cross-links when annealed at 300°C in the presence of 1,8-diiodooctane. Cross-linking is found to

  6. Double-Staining Method for Differentiation of Morphological Changes and Membrane Integrity of Campylobacter coli Cells

    PubMed Central

    Alonso, Jose L.; Mascellaro, Salvatore; Moreno, Yolanda; Ferrús, María A.; Hernández, Javier

    2002-01-01

    We developed a double-staining procedure involving NanoOrange dye (Molecular Probes, Eugene, Oreg.) and membrane integrity stains (LIVE/DEAD BacLight kit; Molecular Probes) to show the morphological and membrane integrity changes of Campylobacter coli cells during growth. The conversion from a spiral to a coccoid morphology via intermediary forms and the membrane integrity changes of the C. coli cells can be detected with the double-staining procedure. Our data indicate that young or actively growing cells are mainly spiral shaped (green-stained cells), but older cells undergo a degenerative change to coccoid forms (red-stained cells). Club-shaped transition cell forms were observed with NanoOrange stain. Chlorinated drinking water affected the viability but not the morphology of C. coli cells. PMID:12324366

  7. Morphology control of lithium peroxide using Pd3Co as an additive in aprotic Li-O2 batteries

    NASA Astrophysics Data System (ADS)

    Cho, Sung Man; Yom, Jee Ho; Hwang, Sun Woo; Seong, Il Won; Kim, Jiwoong; Cho, Sung Ho; Yoon, Woo Young

    2017-02-01

    During discharge in aprotic Li-O2 batteries, lithium peroxide (Li2O2) can be formed by a surface- or solution-mediated route. In the surface-mediated process, a Li2O2 film is formed electrochemically on the cathode surface, leading to low capacity and rate capability. In contrast, in high donor or acceptor number electrolyte systems, Li2O2 toroids are formed by solution-mediated growth through a disproportionation reaction, resulting in high capacity and rate capability. However, during charging, high donor or acceptor number solvents cause poor rechargeability because of the high crystallinity of Li2O2 toroids and byproduct formation. Therefore, controlling the size of Li2O2 in a solution-mediated discharge process is the key to the development of Li-O2 batteries with high capacity and good rechargeability. We demonstrate the application of Pd3Co nanoparticles to enhance the rechargeability of a Li-O2 cell in a solution-mediated process. Scanning electron microscopy and X-ray diffraction studies indicate that the Li2O2 particles formed during discharge are small and the decomposition of the reaction products is reversible. A cell fabricated with Pd3Co nanoparticles exhibits a lower overpotential than the one without the nanoparticles. The additive may provide nucleation sites for Li2O2 particles, leading to enhanced rechargeability and appropriate capacity in a solution-mediated process for Li-O2 batteries.

  8. Effects of hypergravity on adipose-derived stem cell morphology, mechanical property and proliferation.

    PubMed

    Tavakolinejad, Alireza; Rabbani, Mohsen; Janmaleki, Mohsen

    2015-08-21

    Alteration in specific inertial conditions can lead to changes in morphology, proliferation, mechanical properties and cytoskeleton of cells. In this report, the effects of hypergravity on morphology of Adipose-Derived Stem Cells (ADSCs) are indicated. ADSCs were repeatedly exposed to discontinuous hypergravity conditions of 10 g, 20 g, 40 g and 60 g by utilizing centrifuge (three times of 20 min exposure, with an interval of 40 min at 1 g). Cell morphology in terms of length, width and cell elongation index and cytoskeleton of actin filaments and microtubules were analyzed by image processing. Consistent changes observed in cell elongation index as morphological change. Moreover, cell proliferation was assessed and mechanical properties of cells in case of elastic modulus of cells were evaluated by Atomic Force Microscopy. Increase in proliferation and decrease in elastic modulus of cells are further results of this study. Staining ADSC was done to show changes in cytoskeleton of the cells associated to hypergravity condition specifically in microfilament and microtubule components. After exposing to hypergravity, significant changes were observed in microfilaments and microtubule density as components of cytoskeleton. It was concluded that there could be a relationship between changes in morphology and MFs as the main component of the cells.

  9. Regulation of mitochondrial morphology and cell cycle by microRNA-214 targeting Mitofusin2.

    PubMed

    Bucha, Sudha; Mukhopadhyay, Debashis; Bhattacharyya, Nitai Pada

    2015-10-02

    Huntington's disease (HD) is an autosomal dominant neurodegenerative disease caused by the increase in CAG repeats beyond 36 at the exon1 of the gene Huntingtin (HTT). Among the various dysfunctions of biological processes in HD, transcription deregulation due to abnormalities in actions of transcription factors has been considered to be one of the important pathological conditions. In addition, deregulation of microRNA (miRNA) expression has been described in HD. Earlier, expression of microRNA-214 (miR-214) has been shown to increase in HD cell models and target HTT gene; the expression of the later being inversely correlated to that of miR-214. In the present communication, we observed that the expressions of several HTT co-expressed genes are modulated by exogenous expression of miR-214 or by its mutant. Among several HTT co-expressed genes, MFN2 was shown to be the direct target of miR-214. Exogenous expression of miR-214, repressed the expression of MFN2, increased the distribution of fragmented mitochondria and altered the distribution of cells in different phases of cell cycle. In summary, we have shown that increased expression of miR-214 observed in HD cell model could target MFN2, altered mitochondrial morphology and deregulated cell cycle. Inhibition of miR-214 could be a possible target of intervention in HD pathogenesis.

  10. Oestradiol and progesterone differentially alter cytoskeletal protein expression and flame cell morphology in Taenia crassiceps.

    PubMed

    Ambrosio, Javier R; Ostoa-Saloma, Pedro; Palacios-Arreola, M Isabel; Ruíz-Rosado, Azucena; Sánchez-Orellana, Pedro L; Reynoso-Ducoing, Olivia; Nava-Castro, Karen E; Martínez-Velázquez, Nancy; Escobedo, Galileo; Ibarra-Coronado, Elizabeth G; Valverde-Islas, Laura; Morales-Montor, Jorge

    2014-09-01

    We examined the effects of oestradiol (E2) and progesterone (P4) on cytoskeletal protein expression in the helminth Taenia crassiceps - specifically actin, tubulin and myosin. These proteins assemble into flame cells, which constitute the parasite excretory system. Total protein extracts were obtained from E2- and P4-treated T. crassiceps cysticerci and untreated controls, and analysed by one- and two-dimensional protein electrophoresis, flow cytometry, immunofluorescence and videomicroscopy. Exposure of T. crassiceps cysticerci to E2 and P4 induced differential protein expression patterns compared with untreated controls. Changes in actin, tubulin and myosin expression were confirmed by flow cytometry of parasite cells and immunofluorescence. In addition, parasite morphology was altered in response to E2 and P4 versus controls. Flame cells were primarily affected at the level of the ciliary tuft, in association with the changes in actin, tubulin and myosin. We conclude that oestradiol and progesterone act directly on T. crassiceps cysticerci, altering actin, tubulin and myosin expression and thus affecting the assembly and function of flame cells. Our results increase our understanding of several aspects of the molecular crosstalk between host and parasite, which might be useful in designing anthelmintic drugs that exclusively impair parasitic proteins which mediate cell signaling and pathogenic reproduction and establishment.

  11. Toxicity Minimized Cryoprotectant Addition and Removal Procedures for Adherent Endothelial Cells

    PubMed Central

    Davidson, Allyson Fry; Glasscock, Cameron; McClanahan, Danielle R.; Benson, James D.; Higgins, Adam Z.

    2015-01-01

    Ice-free cryopreservation, known as vitrification, is an appealing approach for banking of adherent cells and tissues because it prevents dissociation and morphological damage that may result from ice crystal formation. However, current vitrification methods are often limited by the cytotoxicity of the concentrated cryoprotective agent (CPA) solutions that are required to suppress ice formation. Recently, we described a mathematical strategy for identifying minimally toxic CPA equilibration procedures based on the minimization of a toxicity cost function. Here we provide direct experimental support for the feasibility of these methods when applied to adherent endothelial cells. We first developed a concentration- and temperature-dependent toxicity cost function by exposing the cells to a range of glycerol concentrations at 21°C and 37°C, and fitting the resulting viability data to a first order cell death model. This cost function was then numerically minimized in our state constrained optimization routine to determine addition and removal procedures for 17 molal (mol/kg water) glycerol solutions. Using these predicted optimal procedures, we obtained 81% recovery after exposure to vitrification solutions, as well as successful vitrification with the relatively slow cooling and warming rates of 50°C/min and 130°C/min. In comparison, conventional multistep CPA equilibration procedures resulted in much lower cell yields of about 10%. Our results demonstrate the potential for rational design of minimally toxic vitrification procedures and pave the way for extension of our optimization approach to other adherent cell types as well as more complex systems such as tissues and organs. PMID:26605546

  12. ACME: automated cell morphology extractor for comprehensive reconstruction of cell membranes.

    PubMed

    Mosaliganti, Kishore R; Noche, Ramil R; Xiong, Fengzhu; Swinburne, Ian A; Megason, Sean G

    2012-01-01

    The quantification of cell shape, cell migration, and cell rearrangements is important for addressing classical questions in developmental biology such as patterning and tissue morphogenesis. Time-lapse microscopic imaging of transgenic embryos expressing fluorescent reporters is the method of choice for tracking morphogenetic changes and establishing cell lineages and fate maps in vivo. However, the manual steps involved in curating thousands of putative cell segmentations have been a major bottleneck in the application of these technologies especially for cell membranes. Segmentation of cell membranes while more difficult than nuclear segmentation is necessary for quantifying the relations between changes in cell morphology and morphogenesis. We present a novel and fully automated method to first reconstruct membrane signals and then segment out cells from 3D membrane images even in dense tissues. The approach has three stages: 1) detection of local membrane planes, 2) voting to fill structural gaps, and 3) region segmentation. We demonstrate the superior performance of the algorithms quantitatively on time-lapse confocal and two-photon images of zebrafish neuroectoderm and paraxial mesoderm by comparing its results with those derived from human inspection. We also compared with synthetic microscopic images generated by simulating the process of imaging with fluorescent reporters under varying conditions of noise. Both the over-segmentation and under-segmentation percentages of our method are around 5%. The volume overlap of individual cells, compared to expert manual segmentation, is consistently over 84%. By using our software (ACME) to study somite formation, we were able to segment touching cells with high accuracy and reliably quantify changes in morphogenetic parameters such as cell shape and size, and the arrangement of epithelial and mesenchymal cells. Our software has been developed and tested on Windows, Mac, and Linux platforms and is available

  13. Easily accessible polymer additives for tuning the crystal-growth of perovskite thin-films for highly efficient solar cells.

    PubMed

    Dong, Qingqing; Wang, Zhaowei; Zhang, Kaicheng; Yu, Hao; Huang, Peng; Liu, Xiaodong; Zhou, Yi; Chen, Ning; Song, Bo

    2016-03-14

    For perovskite solar cells (Pero-SCs), one of the key issues with respect to the power conversion efficiency (PCE) is the morphology control of the perovskite thin-films. In this study, an easily-accessible additive polyethylenimine (PEI) is utilized to tune the morphology of CH3NH3PbI3-xClx. With addition of 1.00 wt% of PEI, the smoothness and crystallinity of the perovskite were greatly improved, which were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). A summit PCE of 14.07% was achieved for the p-i-n type Pero-SC, indicating a 26% increase compared to those of the devices without the additive. Both photoluminescence (PL) and alternating current impedance spectroscopy (ACIS) analyses confirm the efficiency results after the addition of PEI. This study provides a low-cost polymer additive candidate for tuning the morphology of perovskite thin-films, and might be a new clue for the mass production of Pero-SCs.

  14. Bioeffective Ultrasound at Very Low Doses: Reversible Manipulation of Neuronal Cell Morphology and Function in Vitro

    NASA Astrophysics Data System (ADS)

    Muratore, Robert; LaManna, Justine; Szulman, Erin; Kalisz, M. S. Andrew; Lamprecht, Michael; Simon, M. S. Melissa; Yu, M. S. Zhe; Xu, Nina; Morrison, Barclay

    2009-04-01

    Direct and safe manipulation of neurons by external means is an increasingly studied therapeutic modality with the potential to treat many neurological diseases. Anticipating such future applications, we investigated reversible bioeffects of very low dose focused ultrasound on neuronal cell morphology and function in vitro. To test morphological changes, undifferentiated PC12 cells were serum-cultured. The culture plates were placed on an inverted optical microscope. An f/1.1 ultrasound transducer with a water-filled coupling cone was focused on the culture and excited with 30-ms 4.67-MHz 100-kPa pulses. To test functional changes, rat hippocampal slices were cultured and individually transferred to the well of a 60-channel multi electrode array. An f/2.1 ultrasound transducer with a water-filled coupling cone was focused on a culture and excited with 100-μs 4.04-MHz 77-kPa pulses. The culture was stimulated before and after the ultrasonic stimulus with a 100-μs 100-μA biphasic electrical stimulus. Optical microscopy of PC12 cultures under insonification revealed that cells that were clustered near the ultrasound focal region elongated by approximately 2 μm during insonification and returned to approximately their original shapes following insonification. We conclude that the acoustic radiation force is capable of reversibly deforming cultured cells. In the rat hippocampal cultures, the ultrasonically and electrically evoked responses exhibited similar biphasic waveforms. In addition, robust electrically evoked responses following insonification indicated that the insonified cultures remained viable. We conclude that low-dose ultrasound can stimulate neurons; the mechanism is currently under investigation.

  15. The influence of morphology on charge transport/recombination dynamics in planar perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Yu, Man; Wang, Yi; Wang, Hao-Yi; Han, Jun; Qin, Yujun; Zhang, Jian-Ping; Ai, Xi-Cheng

    2016-10-01

    The photovoltaic performance of planar perovskite solar cell is significantly influenced by the morphology of perovskite film. In this work, five kinds of devices with different perovskite film morphologies were prepared by varying the concentration of CH3NH3Cl in precursor solutions. We found that best morphology of perovskite film results in the excellent photovoltaic performance with an average efficiency of 15.52% and a champion efficiency of 16.38%. Transient photovoltage and photocurrent measurements are performed to elucidate the mechanism of photoelectric conversion processes, which shows that the charge recombination is effectively suppressed and the charge transport is obviously promoted by optimized morphology.

  16. Battery and fuel cell electrodes containing stainless steel charging additive

    DOEpatents

    Zuckerbrod, David; Gibney, Ann

    1984-01-01

    An electrode for use in electrochemical energy cells is made, comprising a hydrophilic layer and a hydrophobic layer, where the hydrophilic layer comprises a hydrophilic composite which includes: (i) carbon particles; (ii) stainless steel particles; (iii) a nonwetting agent; and (iv) a catalyst, where at least one current collector contacts said composite.

  17. Cell Painting, a high-content image-based assay for morphological profiling using multiplexed fluorescent dyes

    PubMed Central

    Bray, Mark-Anthony; Singh, Shantanu; Han, Han; Davis, Chadwick T.; Borgeson, Blake; Hartland, Cathy; Kost-Alimova, Maria; Gustafsdottir, Sigrun M.; Gibson, Christopher C.; Carpenter, Anne E.

    2016-01-01

    In morphological profiling, quantitative data are extracted from microscopy images of cells to identify biologically relevant similarities and differences among samples based on these profiles. This protocol describes the design and execution of experiments using Cell Painting, a morphological profiling assay multiplexing six fluorescent dyes imaged in five channels, to reveal eight broadly relevant cellular components or organelles. Cells are plated in multi-well plates, perturbed with the treatments to be tested, stained, fixed, and imaged on a high-throughput microscope. Then, automated image analysis software identifies individual cells and measures ~1,500 morphological features (various measures of size, shape, texture, intensity, etc.) to produce a rich profile suitable for detecting subtle phenotypes. Profiles of cell populations treated with different experimental perturbations can be compared to suit many goals, such as identifying the phenotypic impact of chemical or genetic perturbations, grouping compounds and/or genes into functional pathways, and identifying signatures of disease. Cell culture and image acquisition takes two weeks; feature extraction and data analysis take an additional 1-2 weeks. PMID:27560178

  18. Cell Painting, a high-content image-based assay for morphological profiling using multiplexed fluorescent dyes.

    PubMed

    Bray, Mark-Anthony; Singh, Shantanu; Han, Han; Davis, Chadwick T; Borgeson, Blake; Hartland, Cathy; Kost-Alimova, Maria; Gustafsdottir, Sigrun M; Gibson, Christopher C; Carpenter, Anne E

    2016-09-01

    In morphological profiling, quantitative data are extracted from microscopy images of cells to identify biologically relevant similarities and differences among samples based on these profiles. This protocol describes the design and execution of experiments using Cell Painting, which is a morphological profiling assay that multiplexes six fluorescent dyes, imaged in five channels, to reveal eight broadly relevant cellular components or organelles. Cells are plated in multiwell plates, perturbed with the treatments to be tested, stained, fixed, and imaged on a high-throughput microscope. Next, an automated image analysis software identifies individual cells and measures ∼1,500 morphological features (various measures of size, shape, texture, intensity, and so on) to produce a rich profile that is suitable for the detection of subtle phenotypes. Profiles of cell populations treated with different experimental perturbations can be compared to suit many goals, such as identifying the phenotypic impact of chemical or genetic perturbations, grouping compounds and/or genes into functional pathways, and identifying signatures of disease. Cell culture and image acquisition takes 2 weeks; feature extraction and data analysis take an additional 1-2 weeks.

  19. Transition-Metal Additives For Long-Life Na/NiCI(2) Cells

    NASA Technical Reports Server (NTRS)

    Bugga, Ratnakumar V.; Surampudi, Subbarao; Halpert, Gerald

    1995-01-01

    Transition-metal additives in cathodes of Na/NiCI(2) high-temperature, rechargeable electrochemical cells found to slow premature fading of charge/discharge capacity. Decline in capacity of cell attributed to agglomeration of Ni particles at cathode: this agglomeration reduces electrochemical area of cathode. Depending on choice of transition-metal additive for particular cell, additive might even participate in desired electrochemical reactions in cell, contributing to specific energy of cell.

  20. Modeling the Excess Cell Surface Stored in a Complex Morphology of Bleb-Like Protrusions

    PubMed Central

    Wessler, Timothy; Yang, Xiaofeng; Chen, Alex; Roach, Nathan; Elston, Timothy C.; Wang, Qi; Jacobson, Ken; Forest, M. Gregory

    2016-01-01

    Cells transition from spread to rounded morphologies in diverse physiological contexts including mitosis and mesenchymal-to-amoeboid transitions. When these drastic shape changes occur rapidly, cell volume and surface area are approximately conserved. Consequently, the rounded cells are suddenly presented with a several-fold excess of cell surface whose area far exceeds that of a smooth sphere enclosing the cell volume. This excess is stored in a population of bleb-like protrusions (BLiPs), whose size distribution is shown by electron micrographs to be skewed. We introduce three complementary models of rounded cell morphologies with a prescribed excess surface area. A 2D Hamiltonian model provides a mechanistic description of how discrete attachment points between the cell surface and cortex together with surface bending energy can generate a morphology that satisfies a prescribed excess area and BLiP number density. A 3D random seed-and-growth model simulates efficient packing of BLiPs over a primary rounded shape, demonstrating a pathway for skewed BLiP size distributions that recapitulate 3D morphologies. Finally, a phase field model (2D and 3D) posits energy-based constitutive laws for the cell membrane, nematic F-actin cortex, interior cytosol, and external aqueous medium. The cell surface is equipped with a spontaneous curvature function, a proxy for the cell surface-cortex couple, that is a priori unknown, which the model “learns” from the thin section transmission electron micrograph image (2D) or the “seed and growth” model image (3D). Converged phase field simulations predict self-consistent amplitudes and spatial localization of pressure and stress throughout the cell for any posited stationary morphology target and cell compartment constitutive properties. The models form a general framework for future studies of cell morphological dynamics in a variety of biological contexts. PMID:27015526

  1. Morphology control of polymer: Fullerene solar cells by nanoparticle self-assembly

    NASA Astrophysics Data System (ADS)

    Zhang, Wenluan

    During the past two decades, research in the field of polymer based solar cells has attracted great effort due to their simple processing, mechanical flexibility and potential low cost. A standard polymer solar cell is based on the concept of a bulk-heterojunction composed of a conducting polymer as the electron donor and a fullerene derivative as the electron acceptor. Since the exciton lifetime is limited, this places extra emphasis on control of the morphology to obtain improved device performance. In this thesis, detailed characterization and novel morphological design of polymer solar cells was studied, in addition, preliminary efforts to transfer laboratory scale methods to industrialized device fabrication was made. Magnetic contrast neutron reflectivity was used to study the vertical concentration distribution of fullerene nanoparticles within poly(2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2- b]thiophene (pBTTT) thin film. Due to the wide space between the side chains of polymer, these fullerene nanoparticles intercalate between them creating a stable co-crystal structure. Therefore, a high volume fraction of fullerene was needed to obtain optimal device performance as phase separated conductive pathways are required and resulted in a homogeneous fullerene concentration profile through the film. Small angle neutron scattering was used to find there is amorphous fullerene even at lower concentration since it was previously believed that all fullerene formed a co-crystal. These fullerene molecules evolve into approximately 15 nm sized agglomerates at higher concentrations to improve electron transport. Unfortunately, thermal annealing gives these agglomerates mobility to form micrometer sized crystals and reduce the device performance. In standard poly(3-hexylthiophene) (P3HT):[6,6]-phenyl-C61-butyric acid methyl ester (PCMBM) solar cells, a higher concentration of PCBM at the cathode interface is desired due to the band alignment structure. This was

  2. Elucidating the effect of the lead iodide complexation degree behind the morphology and performance of perovskite solar cells.

    PubMed

    Mastria, R; Colella, S; Qualtieri, A; Listorti, A; Gigli, G; Rizzo, A

    2017-03-17

    The inclusion of iodide additives in hybrid perovskite precursor solutions has been successfully exploited to improve the solar cell efficiency but their impact on perovskite formation, morphology and photovoltaic performance is still not clear. Here an extensive analysis of the effect of iodide additives in the solution-phase and during the perovskite film formation, as well as their effect on device performance is provided. The results demonstrate that in the solution-phase the additives promote the formation of lead poly-iodide species resulting in the disaggregation of the inorganic lead iodide framework and in the formation of smaller nuclei inducing the growth of uniform and smooth perovskite films. Most importantly, the complexation capability of different iodide additives does not only directly affect film morphology but also influences the density of defect states by varying the stoichiometry of precursors. These findings demonstrate that the fine control of the interactions of the chemical species in the solution-phase is essential for the precise control of the morphology at the nanoscale and the growth of the perovskite films with a reduced density of defect states. Therefore, the in-depth understanding of all the processes involved in the solution-phase is the first step for the development of a facile and reproducible approach for the fabrication of hybrid perovskite solar cells with enhanced photovoltaic performance.

  3. Morphology Analysis and Optimization: Crucial Factor Determining the Performance of Perovskite Solar Cells.

    PubMed

    Zeng, Wenjin; Liu, Xingming; Guo, Xiangru; Niu, Qiaoli; Yi, Jianpeng; Xia, Ruidong; Min, Yong

    2017-03-24

    This review presents an overall discussion on the morphology analysis and optimization for perovskite (PVSK) solar cells. Surface morphology and energy alignment have been proven to play a dominant role in determining the device performance. The effect of the key parameters such as solution condition and preparation atmosphere on the crystallization of PVSK, the characterization of surface morphology and interface distribution in the perovskite layer is discussed in detail. Furthermore, the analysis of interface energy level alignment by using X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy is presented to reveals the correlation between morphology and charge generation and collection within the perovskite layer, and its influence on the device performance. The techniques including architecture modification, solvent annealing, etc. were reviewed as an efficient approach to improve the morphology of PVSK. It is expected that further progress will be achieved with more efforts devoted to the insight of the mechanism of surface engineering in the field of PVSK solar cells.

  4. Fractal morphology of Beta vulgaris L. cell suspension culture permeabilized with Triton X-100®

    NASA Astrophysics Data System (ADS)

    Arenas-Ocampo, M.; Alamilla-Beltrán, L.; Vanegas-Espinoza, P. E.; Camacho-Díaz, B. H.; Campos-Mendiola, R.; Gutiérrez-López, G.; Jiménez-Aparicio, A.

    2012-02-01

    In this work, morphology of Beta vulgaris L. cells permeabilized with 0.7mM of Triton X-100® was evaluated using digital image processing and concepts of fractal dimension (perimeter- area relations). Important morphometric changes were found when the contact-time with chemical agent was increased. The size of cells decreased, the cells lost the roundness and their shape was more sinuous; this behaviour was a result of a probable shrinkage caused by the excess of exposure with the permeabilization agent. Morphology of B. vulgaris cells after permeabilization, exhibited a fractal nature since the slope of the ratio of the logarithm of the perimeter vs logarithm of the area was higher than unit. Fractal geometry of the cell morphology was affected as a result of the exposure to Triton X-100®. Those changes can be attributed to the loss of turgor and structure of the cell wall.

  5. Effects of hierarchical micro/nano-topographies on the morphology, proliferation and differentiation of osteoblast-like cells.

    PubMed

    Huang, Qianli; Elkhooly, Tarek A; Liu, Xujie; Zhang, Ranran; Yang, Xing; Shen, Zhijian; Feng, Qingling

    2016-09-01

    Coating the surfaces of titanium-based implants with appropriate hierarchical micro/nano-topographies resembling the structure of natural bone significantly enhances their biological performance. However, the relationship between nanostructures surfaces and their effects on modulating cellular response is not clearly understood. Moreover, it is not clear whether the surface chemistry or topography is the main factor on modulating cellular behavior, because the commonly used surface modification techniques for titanium-based implants simultaneously modify surface topography and chemistry. The aim of this study is to investigate osteoblast-like cell adhesion, proliferation and differentiation on hierarchical micro/nano-topographies with similar surface chemistry but different nano-scale features. Micro-arc oxidation and post hydrothermal treatment were employed to fabricate micro/nano-topographies on titanium. According to the morphological features, they were classified as microcrater (micro-topography), nanoplate (hierarchical topography with nanoplates) and nanoleaf (hierarchical topography with nanoleaves). The response of osteoblast like cells (SaOS-2) was studied on each surface after sputtering with a thin layer of gold (Au) to minimize the influence of surface chemistry. The morphological evaluation after histochemical staining revealed that the adherent cells were polygonal-shaped on microcrater surface, roundish on nanoplate surface and elongated on nanoleaf surface. Additionally, compared to microcrater surface, nanoplate surface slowed down cell proliferation and exhibited no enhancement on cell differentiation. However, nanoleaf surface supported cell proliferation and promoted cell differentiation. The results indicate that tuning morphological features of nanostructures on micro-topography can serve as a promising strategy to specifically modulate cellular response, such as cell morphology, proliferation, differentiation and mineralization.

  6. The rap GTPases regulate B cell morphology, immune-synapse formation, and signaling by particulate B cell receptor ligands.

    PubMed

    Lin, Kevin B L; Freeman, Spencer A; Zabetian, Saba; Brugger, Hayley; Weber, Michele; Lei, Victor; Dang-Lawson, May; Tse, Kathy W K; Santamaria, Rene; Batista, Facundo D; Gold, Michael R

    2008-01-01

    B lymphocytes spread and extend membrane processes when searching for antigens and form immune synapses upon contacting cells that display antigens on their surface. Although these dynamic morphological changes facilitate B cell activation, the signaling pathways underlying these processes are not fully understood. We found that activation of the Rap GTPases was essential for these changes in B cell morphology. Rap activation was important for B cell receptor (BCR)- and lymphocyte-function-associated antigen-1 (LFA-1)-induced spreading, for BCR-induced immune-synapse formation, and for particulate BCR ligands to induce localized F-actin assembly and membrane-process extension. Rap activation and F-actin assembly were also required for optimal BCR signaling in response to particulate antigens but not soluble antigens. Thus by controlling B cell morphology and cytoskeletal organization, Rap might play a key role in the activation of B cells by particulate and cell-associated antigens.

  7. Morphology and expression status investigations of specific surface markers on B-cell chronic lymphocytic leukemia cells.

    PubMed

    Niu, Suli; Chan, Ryan; Berini, Pierre; Wang, Chen; Zou, Shan

    2013-11-01

    The morphology of cells and expression status of specific surface markers [cluster of differentiation (CD)], such as CD5, CD19, CD20, CD38, and CD45, have long been considered as the essential indicators for the diagnosis and prognosis of B-cell chronic lymphocytic leukemia (B-CLL). Clinically, it is difficult to simultaneously obtain cell morphology and distribution of surface markers with flow cytometry, especially for some surrogate markers such as CD38. Here, as an alternative and complementary prognostic method, fluorescence microscopy and image processing method are introduced to directly visualize the cells from patients and to quantitatively determine the expression status of surface markers. In this study, the morphological parameters of B-CLL cells were measured to establish the correlation between the cellular morphology and the surface marker expression. It was clear that the CD38+ and CD38- B-CLL cells from the same CD38+ patients had hardly any size differences; however, an increase in perimeter was observed for CD38- patients. Moreover, the expression level of the receptors on the cell was independent of the cell size. There was no evidence showing that the expression intensities of CD19 and CD38 were related to each other for the CD38+ B-CLL cells. On the same cells, CD5 was more selectively expressed on the cell membrane; however, the expression patterns suggested that the cell membrane of CD38- B-CLL cells contained the least expression level of CD19.

  8. Morphology of human embryonic kidney cells in culture after space flight

    NASA Technical Reports Server (NTRS)

    Todd, P.; Kunze, M. E.; Williams, K.; Morrison, D. R.; Lewis, M. L.; Barlow, G. H.

    1985-01-01

    The ability of human embyronic kidney cells to differentiate into small epithelioid, large epithelioid, domed, and fenestrated morphological cell types following space flight is examined. Kidney cells exposed to 1 day at 1 g, then 1 day in orbit, and a 12 minute passage through the electrophoretic separator are compared with control cultures. The data reveal that 70 percent of small epithelioid, 16 percent of large epithelioid, 9 percent of dome-forming, and 5 percent of fenestrated cells formed in the space exposed cells; the distributions correlate well with control data. The formation of domed cells from cells cultured from low electrophoretic mobility fractions and small epithelioid cells from high mobility fractions is unaffected by space flight conditions. It is concluded that storage under microgravity conditions does not influence the morphological differentiation of human embryonic kidney cells in low-passage culture.

  9. Endothelial Cell Morphology and Migration are Altered by Changes in Gravitational Fields

    NASA Technical Reports Server (NTRS)

    Melhado, Caroline; Sanford, Gary; Harris-Hooker, Sandra

    1997-01-01

    Many of the physiological changes of the cardiovascular system during space flight may originate from the dysfunction of basic biological mechanisms caused by microgravity. The weightlessness affects the system when blood and other fluids move to the upper body causing the heart to enlarge to handle the increased blood flow to the upper extremities and decrease circulating volume. Increase arterial pressure triggers baroreceptors which signal the brain to adjust heart rate. Hemodynarnic studies indicate that the microgravity-induced headward fluid redistribution results in various cardiovascular changes such as; alteration of vascular permeability resulting in lipid accumulation in the lumen of the vasculature and degeneration of the the vascular wall, capillary alteration with extensive endothelial invagination. Achieving a true microgravity environment in ground based studies for prolonged periods is virtually impossible. The application of vector-averaged gravity to mammalian cells using horizontal clinostat produces alterations of cellular behavior similar to those observed in microgravity. Similarly, the low shear, horizontally rotating bioreactor (originally designed by NASA) also duplicates several properties of microgravity. Additionally, increasing gravity, i.e., hypcrgravity is easily achieved. Hypergravity has been found to increase the proliferation of several different cell lines (e.g., chick embryo fibroblasts) while decreasing cell motility and slowing liver regeneration following partial hepatectomy. The effect of altered gravity on cells maybe similar to those of other physical forces, i.e. shear stress. Previous studies examining laminar flow and shear stress on endothelial cells found that the cells elongate, orient with the direction of flow, and reorganize their F-actin structure, with concomitant increase in cell stiffness. These studies suggest that alterations in the gravity environment will change the behavior of most cells, including

  10. Morphology and connectivity of the small bistratified A8 amacrine cell in the mouse retina

    PubMed Central

    Lee, Sammy C.S.; Meyer, Arndt; Schubert, Timm; Hüser, Laura; Dedek, Karin; Haverkamp, Silke

    2015-01-01

    Amacrine cells comprise ~30 morphological types in the mammalian retina. The synaptic connectivity and function of a few GABAergic wide-field amacrine cells have recently been studied, however, with the exception of the rod pathway-specific AII amacrine cell the connectivity of glycinergic small-field amacrine cells has not been investigated in the mouse retina. Here, we studied the morphology and connectivity pattern of the small-field A8 amacrine cell. A8 cells in mouse retina are bistratified with lobular processes in the ON sublamina and arboreal dendrites in the OFF sublamina of the inner plexiform layer. The distinct bistratified morphology was first visible at postnatal day 8, reaching the adult shape at P13, around eye opening. The connectivity of A8 cells to bipolar cells and ganglion cells was studied by double and triple immunolabeling experiments using various cell markers combined with synaptic markers. Our data suggest that A8 amacrine cells receive glutamatergic input from both OFF and ON cone bipolar cells. Furthermore, A8 cells are coupled to ON cone bipolar cells by gap junctions, and provide inhibitory input via glycine receptor (GlyR) subunit α1 to OFF cone bipolar cells and to ON A-type ganglion cells. Measurements of spontaneous glycinergic postsynaptic currents and GlyR immunolabeling revealed that A8 cells express GlyRs containing the α2 subunit. Taken together, the bistratified A8 cell makes very similar synaptic contacts with cone bipolar cells as the rod pathway-specific AII amacrine cell. However, unlike AII cells, A8 amacrine cells provide glycinergic input to ON A-type ganglion cells. PMID:25630271

  11. Late steps of parvoviral infection induce changes in cell morphology.

    PubMed

    Pakkanen, Kirsi; Nykky, Jonna; Vuento, Matti

    2008-11-01

    Previously, virus-induced non-filopodial extensions have not been encountered in connection with viral infections. Here, we report emergence of long extensions protruding from Norden laboratory feline kidney (NLFK) and A72 (canine fibroma) cells infected with canine parvovirus for 72 h. These extensions significantly differ in length and number from those appearing in control cells. The most striking feature in the extensions is the length, reaching up to 130 microm, almost twice the average length of a healthy NLFK cell. In A72 cells, the extensions were even longer, up to 200 microm. The results presented here also suggest that the events leading to the growth of these extensions start earlier in infection and abnormal extension growth is detectable already at 24-h post-infection (p.i.). These extensions may have a vital role in the cell-to-cell transmission of the virus.

  12. Oleic acid induces specific alterations in the morphology, gene expression and steroid hormone production of cultured bovine granulosa cells.

    PubMed

    Yenuganti, Vengala Rao; Viergutz, Torsten; Vanselow, Jens

    2016-06-01

    After parturition, one of the major problems related to nutritional management that is faced by the majority of dairy cows is negative energy balance (NEB). During NEB, excessive lipid mobilization takes place and hence the levels of free fatty acids, among them oleic acid, increase in the blood, but also in the follicular fluid. This accumulation can be associated with serious metabolic and reproductive disorders. In the present study, we analyzed the effects of physiological concentrations of oleic acid on cell morphology, apoptosis, necrosis, proliferation and steroid production, and on the abundance of selected transcripts in cultured bovine granulosa cells. Increasing oleic acid concentrations induced intracellular lipid droplet accumulation, thus resulting in a foam cell-like morphology, but had no effects on apoptosis, necrosis or proliferation. Oleic acid also significantly reduced the transcript abundance of the gonadotropin hormone receptors, FSHR and LHCGR, steroidogenic genes STAR, CYP11A1, HSD3B1 and CYP19A1, the cell cycle regulator CCND2, but not of the proliferation marker PCNA. In addition, treatment increased the transcript levels of the fatty acid transporters CD36 and SLC27A1, and decreased the production of 17-beta-estradiol and progesterone. From these data it can be concluded that oleic acid specifically affects morphological and physiological features and gene expression levels thus altering the functionality of granulosa cells. Suggestively, these effects might be partly due to the reduced expression of FSHR and thus the reduced responsiveness to FSH stimulation.

  13. Isolation and morphology of Stem Cells from Deciduous Tooth (SHED) and Human Dental Pulp Stem Cells (hDPSC)

    NASA Astrophysics Data System (ADS)

    Ariffin, Shahrul Hisham Zainal; Manogaran, Thanaletchumi; Abidin, Intan Zarina Zainol; Senafi, Sahidan; Wahab, Rohaya Megat Abdul

    2016-11-01

    Dental pulp is a tissue obtained from pulp chamber of deciduous and permanent tooth which contain stem cells. Stem cell isolation procedure is performed to obtain cells from tissue using enzymatic digestion. The aim of this study is to isolate and observe the morphology of stem cells during passage 0 and passage 3. Dental pulp from deciduous and permanent tooth was enzymatically digested using collagenase Type I and cells obtained were cultured in DMEM-KO that contains 10% fetal bovine serum, 1% antibiotic-antimycotic solution and 0.001× GlutaMax®. During culture, cell morphology was observed under the microscope on day 3, 16 and 33 and captured using cellB software. Giemsa staining was conducted on cells at passage 3. Cells attached at the bottom of the flask on day 3 and started forming small colonies. Cells became confluent after approximately 4 weeks. Both Stem Cells from Deciduous Tooth (SHED) and Human Dental Pulp Stem Cells (hDPSC) exhibited fibroblast-like morphology during passage 0 and passage 3. Meanwhile, Giemsa staining at passage 3 revealed single intact nucleus surrounded by fibroblastic cytoplasm structure. It can be concluded that SHED and hDPSC showed consistent fibroblast-like morphology throughout culture period.

  14. Hybrid Solar Cells with Prescribed Nanoscale Morphologies Based onHyperbranched Semiconductor Nanocrystals

    SciTech Connect

    Gur, Ilan; Fromer, Neil A.; Chen, Chih-Ping; Kanaras, AntoniosG.; Alivisatos, A. Paul

    2006-09-09

    In recent years, the search to develop large-area solar cells at low cost has led to research on photovoltaic (PV) systems based on nanocomposites containing conjugated polymers. These composite films can be synthesized and processed at lower costs and with greater versatility than the solid state inorganic semiconductors that comprise today's solar cells. However, the best nanocomposite solar cells are based on a complex architecture, consisting of a fine blend of interpenetrating and percolating donor and acceptor materials. Cell performance is strongly dependent on blend morphology, and solution-based fabrication techniques often result in uncontrolled and irreproducible blends, whose composite morphologies are difficult to characterize accurately. Here we incorporate 3-dimensional hyper-branched colloidal semiconductor nanocrystals in solution-processed hybrid organic-inorganic solar cells, yielding reproducible and controlled nanoscale morphology.

  15. Control of cell morphology of probiotic Lactobacillus acidophilus for enhanced cell stability during industrial processing.

    PubMed

    Senz, Martin; van Lengerich, Bernhard; Bader, Johannes; Stahl, Ulf

    2015-01-02

    The viability of bacteria during industrial processing is an essential quality criterion for bacterial preparations, such as probiotics and starter cultures. Therefore, producing stable microbial cultures during proliferation is of great interest. A strong correlation between the culture medium and cellular morphology was observed for the lactic acid bacterium Lactobacillus acidophilus NCFM, which is commonly used in the dairy industry as a probiotic supplement and as a starter culture. The cell shapes ranged from single short rods to long filamentous rods. The culture medium composition could control this phenomenon of pleomorphism, especially the use of peptone in combination with an adequate heating of the medium during preparation. Furthermore, we observed a correlation between the cell size and stability of the microorganisms during industrial processing steps, such as freeze-drying, extrusion encapsulation and storage following dried preparations. The results revealed that short cells are more stable than long cells during each of the industrially relevant processing steps. As demonstrated for L. acidophilus NCFM, the adaptation of the medium composition and optimized medium preparation offer the possibility to increase the concentration of viable cells during up- and survival rate during down-stream processing.

  16. Comparing Two Intestinal Porcine Epithelial Cell Lines (IPECs): Morphological Differentiation, Function and Metabolism

    PubMed Central

    Nossol, Constanze; Barta-Böszörményi, Anicò; Kahlert, Stefan; Zuschratter, Werner; Faber-Zuschratter, Heidi; Reinhardt, Nicole; Ponsuksili, Siriluk; Wimmers, Klaus; Diesing, Anne-Kathrin; Rothkötter, Hermann-Josef

    2015-01-01

    The pig shows genetical and physiological resemblance to human, which predestines it as an experimental animal model especially for mucosal physiology. Therefore, the intestinal epithelial cell lines 1 and J2 (IPEC-1, IPEC-J2) - spontaneously immortalised cell lines from the porcine intestine - are important tools for studying intestinal function. A microarray (GeneChip Porcine Genome Array) was performed to compare the genome wide gene expression of IPECs. Different significantly up-regulated pathways were identified, like “lysosome”, “pathways in cancer”, “regulation of actin cytoskeleton” and “oxidative phosphorylation” in IPEC-J2 in comparison to IPEC-1. On the other hand, “spliceosome”, “ribosome”, “RNA-degradation” and “tight junction” are significantly down-regulated pathways in IPEC-J2 in comparison to IPEC-1. Examined pathways were followed up by functional analyses. ATP-, oxygen, glucose and lactate-measurement provide evidence for up-regulation of oxidative phosphorylation in IPEC-J2. These cells seem to be more active in their metabolism than IPEC-1 cells due to a significant higher ATP-content as well as a higher O2- and glucose-consumption. The down-regulated pathway “ribosome” was followed up by measurement of RNA- and protein content. In summary, IPEC-J2 is a morphologically and functionally more differentiated cell line in comparison to IPEC-1. In addition, IPEC-J2 cells are a preferential tool for in vitro studies with the focus on metabolism. PMID:26147118

  17. 1,8-Diiodooctane as the processing additive to improve the efficiency of P3HT:PC61BM solar cells.

    PubMed

    Fan, Xing; Zhao, Suling; Yue, Cui; Yang, Qianqian; Gong, Wei; Chen, Yu; Wang, Huanhua; Jia, Quanjie; Xu, Zheng; Xu, Xurong

    2014-05-01

    Controlling the blend morphology is critical for achieving high power conversion efficiency in polymer/fullerene bulk heterojunction (BHJ) photovoltaic devices. As a simple and effective method to control morphology, adding processing additives has been widely applied in the organic BHJ solar cells. In this paper, we demonstrate that adding 1,8-diiodooctane as a processing additives is an effective method to improve the morphology and the efficiency of bulk heterojunctions (BHJ) solar cells based on the regioregular poly(3-hexylthiophene) (P3HT) and a soluble fullerene derivative ([6,6]-phenyl C61-butyric acid methyl ester, PC61BM). We investigated the unique way in which the 1,8-diiodooctane plays the rule to enhance the performance of solar cells according to different morphology and crystallinity of active layers prepared with and without the additive. The morphology is studied with atomic force microscopy (AFM) and Grazing Incidence X-ray Diffraction (GIXRD). We also find a balance between a large interfacial area for exciton dissociation and continuous pathways for carrier transportation when the additive is used.

  18. Effects of hypergravity on adipose-derived stem cell morphology, mechanical property and proliferation

    SciTech Connect

    Tavakolinejad, Alireza; Rabbani, Mohsen; Janmaleki, Mohsen

    2015-08-21

    Alteration in specific inertial conditions can lead to changes in morphology, proliferation, mechanical properties and cytoskeleton of cells. In this report, the effects of hypergravity on morphology of Adipose-Derived Stem Cells (ADSCs) are indicated. ADSCs were repeatedly exposed to discontinuous hypergravity conditions of 10 g, 20 g, 40 g and 60 g by utilizing centrifuge (three times of 20 min exposure, with an interval of 40 min at 1 g). Cell morphology in terms of length, width and cell elongation index and cytoskeleton of actin filaments and microtubules were analyzed by image processing. Consistent changes observed in cell elongation index as morphological change. Moreover, cell proliferation was assessed and mechanical properties of cells in case of elastic modulus of cells were evaluated by Atomic Force Microscopy. Increase in proliferation and decrease in elastic modulus of cells are further results of this study. Staining ADSC was done to show changes in cytoskeleton of the cells associated to hypergravity condition specifically in microfilament and microtubule components. After exposing to hypergravity, significant changes were observed in microfilaments and microtubule density as components of cytoskeleton. It was concluded that there could be a relationship between changes in morphology and MFs as the main component of the cells. - Highlights: • Hypergravity (10 g, 20 g, 40 g and 60 g) affects on adipose derived stem cells (ADSCs). • ADSCs after exposure to the hypergravity are more slender. • The height of ADSCs increases in all test groups comparing their control group. • Hypergravity decreases ADSCs modulus of elasticity and cell actin fiber content. • Hypergravity enhances proliferation rate of ADSCs.

  19. Effect of surface potential on epithelial cell adhesion, proliferation and morphology.

    PubMed

    Chang, Hsun-Yun; Kao, Wei-Lun; You, Yun-Wen; Chu, Yi-Hsuan; Chu, Kuo-Jui; Chen, Peng-Jen; Wu, Chen-Yi; Lee, Yu-Hsuan; Shyue, Jing-Jong

    2016-05-01

    Cell adhesion is the basis of individual cell survival, division and motility. Hence, understanding the effects that the surface properties have on cell adhesion, proliferation and morphology are crucial. In particular, surface charge/potential has been identified as an important factor that affects cell behavior. However, how cells respond to incremental changes in surface potential remains unclear. By using binary self-assembled monolayer (SAM) modified Au surfaces that are similar in mechanical/chemical properties and provide a series of surface potentials, the effect of surface potential on the behavior of cells can be studied. In this work, the effect of surface potential on epithelial cells, including human embryonic kidney (HEK293T) and human hepatocellular carcinoma (HepG2), were examined. The results showed that the adhesion density of epithelial cells increased with increasing surface potential, which is similar to but varied more significantly compared with fibroblasts. The proliferation rate is found to be independent of surface potential in both cell types. Furthermore, epithelial cells show no morphological change with respect to surface potential, whereas the morphology of the fibroblasts clearly changed with the surface potential. These differences between the cell types were rationalized by considering the difference in extracellular matrix composition. Laminin-dominant epithelial cells showed higher adhesion density and less morphological change than did fibronectin-dominant fibroblasts because the more significant adsorption of positively charged laminin on the surface enhanced the adhesion of epithelial cells. In contrast, due to the dominance of negatively charged fibronectin that adsorbed weakly on the surface, fibroblasts had to change their morphology to fit the inhomogeneous fibronectin-adsorbed area.

  20. A morphological study of the retinal ganglion cells of the Afghan pika (Ochotona rufescens).

    PubMed

    Akaishi, Y; Uchiyama, H; Ito, H; Shimizu, Y

    1995-03-01

    The distribution and morphology of the retinal ganglion cells was studied in a relative of the rabbit, the Afghan pika. The total number of retinal ganglion cells was approximately 170,000. The total number of optic nerve fibers was between 160,000 and 190,000, corresponding to the total number of retinal ganglion cells. Retinal ganglion cells were found to have a horizontal region of high-density. The maximum density was 5250 cells/mm2. This region was located in the central retina below the optic disc. This area contained numerous closely packed small ganglion cells, while the peripheral retina (especially in the dorsal periphery) contained large ganglion cells more loosely dispersed. The retinal ganglion cells labeled by horseradish peroxidase (HRP) were morphologically classified into three types based on dendritic length and ramification pattern.

  1. Improved method for the quantification of motility in glia and other morphologically complex cells.

    PubMed

    Sild, Mari; Chatelain, Robert P; Ruthazer, Edward S

    2013-01-01

    Cells such as astrocytes and radial glia with many densely ramified, fine processes pose particular challenges for the quantification of structural motility. Here we report the development of a method to calculate a motility index for individual cells with complex, dynamic morphologies. This motility index relies on boxcar averaging of the difference images generated by subtraction of images collected at consecutive time points. An image preprocessing step involving 2D projection, edge detection, and dilation of the raw images is first applied in order to binarize the images. The boxcar averaging of difference images diminishes the impact of artifactual pixel fluctuations while accentuating the group-wise changes in pixel values which are more likely to represent real biological movement. Importantly, this provides a value that correlates with mean process elongation and retraction rates without requiring detailed reconstructions of very complex cells. We also demonstrate that additional increases in the sensitivity of the method can be obtained by denoising images using the temporal frequency power spectra, based on the fact that rapid intensity fluctuations over time are mainly due to imaging artifact. The MATLAB programs implementing these motility analysis methods, complete with user-friendly graphical interfaces, have been made publicly available for download.

  2. Effects of solvent additive on “s-shaped” curves in solution-processed small molecule solar cells

    PubMed Central

    Chou, Shu-Hua; Huang, Ye

    2016-01-01

    A novel molecular chromophore, p-SIDT(FBTThCA8)2, is introduced as an electron-donor material for bulk heterojunction (BHJ) solar cells with broad absorption and near ideal energy levels for the use in combination with common acceptor materials. It is found that films cast from chlorobenzene yield devices with strongly s-shaped current–voltage curves, drastically limiting performance. We find that addition of the common solvent additive diiodooctane, in addition to facilitating crystallization, leads to improved vertical phase separation. This yields much better performing devices, with improved curve shape, demonstrating the importance of morphology control in BHJ devices and improving the understanding of the role of solvent additives. PMID:28144323

  3. Parametric analysis of colony morphology of non-labelled live human pluripotent stem cells for cell quality control

    PubMed Central

    Kato, Ryuji; Matsumoto, Megumi; Sasaki, Hiroto; Joto, Risako; Okada, Mai; Ikeda, Yurika; Kanie, Kei; Suga, Mika; Kinehara, Masaki; Yanagihara, Kana; Liu, Yujung; Uchio-Yamada, Kozue; Fukuda, Takayuki; Kii, Hiroaki; Uozumi, Takayuki; Honda, Hiroyuki; Kiyota, Yasujiro; Furue, Miho K

    2016-01-01

    Given the difficulties inherent in maintaining human pluripotent stem cells (hPSCs) in a healthy state, hPSCs should be routinely characterized using several established standard criteria during expansion for research or therapeutic purposes. hPSC colony morphology is typically considered an important criterion, but it is not evaluated quantitatively. Thus, we designed an unbiased method to evaluate hPSC colony morphology. This method involves a combination of automated non-labelled live-cell imaging and the implementation of morphological colony analysis algorithms with multiple parameters. To validate the utility of the quantitative evaluation method, a parent cell line exhibiting typical embryonic stem cell (ESC)-like morphology and an aberrant hPSC subclone demonstrating unusual colony morphology were used as models. According to statistical colony classification based on morphological parameters, colonies containing readily discernible areas of differentiation constituted a major classification cluster and were distinguishable from typical ESC-like colonies; similar results were obtained via classification based on global gene expression profiles. Thus, the morphological features of hPSC colonies are closely associated with cellular characteristics. Our quantitative evaluation method provides a biological definition of ‘hPSC colony morphology’, permits the non-invasive monitoring of hPSC conditions and is particularly useful for detecting variations in hPSC heterogeneity. PMID:27667091

  4. Auxin regulates SNARE-dependent vacuolar morphology restricting cell size.

    PubMed

    Löfke, Christian; Dünser, Kai; Scheuring, David; Kleine-Vehn, Jürgen

    2015-03-05

    The control of cellular growth is central to multicellular patterning. In plants, the encapsulating cell wall literally binds neighbouring cells to each other and limits cellular sliding/migration. In contrast to its developmental importance, growth regulation is poorly understood in plants. Here, we reveal that the phytohormone auxin impacts on the shape of the biggest plant organelle, the vacuole. TIR1/AFBs-dependent auxin signalling posttranslationally controls the protein abundance of vacuolar SNARE components. Genetic and pharmacological interference with the auxin effect on vacuolar SNAREs interrelates with auxin-resistant vacuolar morphogenesis and cell size regulation. Vacuolar SNARE VTI11 is strictly required for auxin-reliant vacuolar morphogenesis and loss of function renders cells largely insensitive to auxin-dependent growth inhibition. Our data suggests that the adaptation of SNARE-dependent vacuolar morphogenesis allows auxin to limit cellular expansion, contributing to root organ growth rates.

  5. Systematic morphological profiling of human gene and allele function via Cell Painting.

    PubMed

    Rohban, Mohammad Hossein; Singh, Shantanu; Wu, Xiaoyun; Berthet, Julia B; Bray, Mark-Anthony; Shrestha, Yashaswi; Varelas, Xaralabos; Boehm, Jesse S; Carpenter, Anne E

    2017-03-18

    We hypothesized that human genes and disease-associated alleles might be systematically functionally annotated using morphological profiling of cDNA constructs, via a microscopy-based Cell Painting assay. Indeed, 50% of the 220 tested genes yielded detectable morphological profiles, which grouped into biologically meaningful gene clusters consistent with known functional annotation (e.g., the RAS-RAF-MEK-ERK cascade). We used novel subpopulation-based visualization methods to interpret the morphological changes for specific clusters. This unbiased morphologic map of gene function revealed TRAF2/c-REL negative regulation of YAP1/WWTR1-responsive pathways. We confirmed this discovery of functional connectivity between the NF-κB pathway and Hippo pathway effectors at the transcriptional level, thereby expanding knowledge of these two signaling pathways that critically regulate tumor initiation and progression. We make the images and raw data publicly available, providing an initial morphological map of major biological pathways for future study.

  6. Modification of the surface morphology of 4H-SiC by addition of Sn and Al in solution growth with SiCr solvents

    NASA Astrophysics Data System (ADS)

    Komatsu, Naoyoshi; Mitani, Takeshi; Hayashi, Yuichiro; Kato, Tomohisa; Harada, Shunta; Ujihara, Toru; Okumura, Hajime

    2017-01-01

    For solution growth of 4H-SiC with Si0.6-x-yCr0.4AlxSny solvents, the changes in surface morphology and polytype induced by the addition of Sn and Al to the Si0.6Cr0.4 solvent were investigated. Growth with Si0.6Cr0.4 solvents resulted in a rough surface covered with large macrosteps that were several micrometers high, and the polytype of the grown layer transformed to 6H and 15R-SiC. The surface roughening and polytype instability were suppressed when more than 2 at% Al was added to the SiCr0.4 solvent. We also found that the combined addition of both 2-4 at% Sn and 0.5-1 at% Al resulted in smooth surface morphology. We discussed the modification of the surface morphology of 4H-SiC caused by the additives in terms of the wetting properties of the solvents. Based on the results of experiments and thermodynamic calculations, the addition of both Sn and Al increased the liquid/solid interfacial energy. Because the two-dimensional nucleation energy increases with the interfacial energy, we conclude that smooth step flow growth of 4H-SiC was achieved by lowering the frequency of two-dimensional nucleation on the growth surface.

  7. Protein SUMOylation is Involved in Cell-cycle Progression and Cell Morphology in Giardia lamblia.

    PubMed

    Di Genova, Bruno M; da Silva, Richard C; da Cunha, Júlia P C; Gargantini, Pablo R; Mortara, Renato A; Tonelli, Renata R

    2016-11-19

    The unicellular protozoa Giardia lamblia is a food- and waterborne parasite that causes giardiasis. This illness is manifested as acute and self-limited diarrhea and can evolve to long-term complications. Successful establishment of infection by Giardia trophozoites requires adhesion to host cells and colonization of the small intestine, where parasites multiply by mitotic division. The tight binding of trophozoites to host cells occurs by means of the ventral adhesive disc, a spiral array of microtubules and associated proteins such as giardins. In this work we show that knock down of the Small Ubiquitin-like MOdifier (SUMO) results in less adhesive trophzoites, decreased cell proliferation and deep morphological alterations, including at the ventral disc. Consistent with the reduced proliferation, SUMO knocked-down trophozoites were arrested in G1 and in S phases of the cell cycle. Mass spectrometry analysis of anti-SUMO immunoprecipitates was performed to identify SUMO substrates possibly involved in these events. Among the identified SUMOylation targets, α-tubulin was further validated by Western blot and confirmed to be a SUMO target in Giardia trophozoites.

  8. Cytokines profile and peripheral blood mononuclear cells morphology in Rett and autistic patients.

    PubMed

    Pecorelli, Alessandra; Cervellati, Franco; Belmonte, Giuseppe; Montagner, Giulia; Waldon, PhiAnh; Hayek, Joussef; Gambari, Roberto; Valacchi, Giuseppe

    2016-01-01

    A potential role for immune dysfunction in autism spectrum disorders (ASD) has been well established. However, immunological features of Rett syndrome (RTT), a genetic neurodevelopmental disorder closely related to autism, have not been well addressed yet. By using multiplex Luminex technology, a panel of 27 cytokines and chemokines was evaluated in serum from 10 RTT patients with confirmed diagnosis of MECP2 mutation (typical RTT), 12 children affected by classic autistic disorder and 8 control subjects. The cytokine/chemokine gene expression was assessed by real time PCR on mRNA of isolated peripheral blood mononuclear cells (PBMCs). Moreover, ultrastructural analysis of PBMCs was performed using transmission electron microscopy (TEM). Significantly higher serum levels of interleukin-8 (IL-8), IL-9, IL-13 were detected in RTT compared to control subjects, and IL-15 shows a trend toward the upregulation in RTT. In addition, IL-1β and VEGF were the only down-regulated cytokines in autistic patients with respect to RTT. No difference in cytokine/chemokine profile between autistic and control groups was detected. These data were also confirmed by ELISA real time PCR. At the ultrastructural level, the most severe morphological abnormalities were observed in mitochondria of both RTT and autistic PBMCs. In conclusion, our study shows a deregulated cytokine/chemokine profile together with morphologically altered immune cells in RTT. Such abnormalities were not quite as evident in autistic subjects. These findings indicate a possible role of immune dysfunction in RTT making the clinical features of this pathology related also to the immunology aspects, suggesting, therefore, novel possible therapeutic interventions for this disorder.

  9. Prenatal stress is a vulnerability factor for altered morphology and biological activity of microglia cells

    PubMed Central

    Ślusarczyk, Joanna; Trojan, Ewa; Głombik, Katarzyna; Budziszewska, Bogusława; Kubera, Marta; Lasoń, Władysław; Popiołek-Barczyk, Katarzyna; Mika, Joanna; Wędzony, Krzysztof; Basta-Kaim, Agnieszka

    2015-01-01

    Several lines of evidence suggest that the dysregulation of the immune system is an important factor in the development of depression. Microglia are the resident macrophages of the central nervous system and a key player in innate immunity of the brain. We hypothesized that prenatal stress (an animal model of depression) as a priming factor could affect microglial cells and might lead to depressive-like disturbances in adult male rat offspring. We investigated the behavioral changes (sucrose preference test, Porsolt test), the expression of C1q and CD40 mRNA and the level of microglia (Iba1 positive) in 3-month-old control and prenatally stressed male offspring rats. In addition, we characterized the morphological and biochemical parameters of potentially harmful (NO, iNOS, IL-1β, IL-18, IL-6, TNF-α, CCL2, CXCL12, CCR2, CXCR4) and beneficial (insulin-like growth factor-1 (IGF-1), brain derived neurotrophic factor (BDNF)) phenotypes in cultures of microglia obtained from the cortices of 1–2 days old control and prenatally stressed pups. The adult prenatally stressed rats showed behavioral (anhedonic- and depression-like) disturbances, enhanced expression of microglial activation markers and an increased number of Iba1-immunopositive cells in the hippocampus and frontal cortex. The morphology of glia was altered in cultures from prenatally stressed rats, as demonstrated by immunofluorescence microscopy. Moreover, in these cultures, we observed enhanced expression of CD40 and MHC II and release of pro-inflammatory cytokines, including IL-1β, IL-18, TNF-α and IL-6. Prenatal stress significantly up-regulated levels of the chemokines CCL2, CXCL12 and altered expression of their receptors, CCR2 and CXCR4 while IGF-1 production was suppressed in cultures of microglia from prenatally stressed rats. Our results suggest that prenatal stress may lead to excessive microglia activation and contribute to the behavioral changes observed in depression in adulthood. PMID

  10. Analysis of cancer cell morphology in fluorescence microscopy image exploiting shape descriptor

    NASA Astrophysics Data System (ADS)

    Kang, Mi-Sun; Kim, Hye-Ryun; Kim, Sudong; Ryu, Gyu Ha; Kim, Myoung-Hee

    2016-04-01

    Cancer cell morphology is closely related to their phenotype and activity. These characteristics are important in drug-response prediction for personalized cancer therapeutics. We used multi-channel fluorescence microscopy images to analyze the morphology of highly cohesive cancer cells. First, we detected individual nuclei regions in single-channel images using advanced simple linear iterative clustering. The center points of the nuclei regions were used as seeds for the Voronoi diagram method to extract spatial arrangement features from cell images. Human cancer cell populations form irregularly shaped aggregates, making their detection more difficult. We overcame this problem by identifying individual cells using an image-based shape descriptor. Finally, we analyzed the correlation between cell agglutination and cell shape.

  11. Limits of Applicability of the Voronoi Tessellation Determined by Centers of Cell Nuclei to Epithelium Morphology.

    PubMed

    Kaliman, Sara; Jayachandran, Christina; Rehfeldt, Florian; Smith, Ana-Sunčana

    2016-01-01

    It is well accepted that cells in the tissue can be regarded as tiles tessellating space. A number of approaches were developed to find an appropriate mathematical description of such cell tiling. A particularly useful approach is the so called Voronoi tessellation, built from centers of mass of the cell nuclei (CMVT), which is commonly used for estimating the morphology of cells in epithelial tissues. However, a study providing a statistically sound analysis of this method's accuracy is not available in the literature. We addressed this issue here by comparing a number of morphological measures of the cells, including area, perimeter, and elongation obtained from such a tessellation with identical measures extracted from direct imaging acquired by staining the cell membranes. After analyzing the shapes of 15,000 MDCK II epithelial cells under several conditions, we find that CMVT reasonably well reproduces many of the morphological properties of the tissue with an error that is between 10 and 15%. Moreover, cross-correlations between different morphological measures are reproduced qualitatively correctly by this method. However, all of the properties including the cell perimeters, number of neighbors, and anisotropy measures often suffer from systematic or size dependent errors. These discrepancies originate from the polygonal nature of the tessellation which sets the limits of the applicability of CMVT.

  12. Comparison of the Cell-Wall Composition of Morphologically Distinct Actinomycetes

    PubMed Central

    Yamaguchi, Tatsuro

    1965-01-01

    Yamaguchi, Tatsuro (The University of Tokyo, Tokyo, Japan). Comparison of the cell-wall composition of morphologically distinct actinomycetes. J. Bacteriol. 89:444–453. 1965.—Cell-wall composition of various morphologically distinct actinomycetes was studied to determine the relationship, if any, between cell-wall composition and morphological criteria in actinomycete taxonomy. The methods used were similar to those of Cummins and Harris. At least five types of cell-wall composition were obtained; however, these were not always correlated with groupings by the conventional classification system. For instance, the sporangium-forming actinomycetes, Actinoplanaceae, had three types of cell-wall composition; the composition of cell walls of Promicromonospora, Micromonospora, and Microbispora was the same as, or similar to, that of Actinomyces, Actinoplanes, and Streptosporangium, respectively; Chainia, Actinopycnidium, Actinosporangium, and Microellobosporia had the same cell-wall composition as Streptomyces, whereas that of Streptoverticillium was slightly different. Possible implications of cell-wall composition and morphological differentiation of hyphae for the taxonomy and phylogeny of actinomycetes are also discussed. PMID:14255713

  13. Limits of Applicability of the Voronoi Tessellation Determined by Centers of Cell Nuclei to Epithelium Morphology

    PubMed Central

    Kaliman, Sara; Jayachandran, Christina; Rehfeldt, Florian; Smith, Ana-Sunčana

    2016-01-01

    It is well accepted that cells in the tissue can be regarded as tiles tessellating space. A number of approaches were developed to find an appropriate mathematical description of such cell tiling. A particularly useful approach is the so called Voronoi tessellation, built from centers of mass of the cell nuclei (CMVT), which is commonly used for estimating the morphology of cells in epithelial tissues. However, a study providing a statistically sound analysis of this method's accuracy is not available in the literature. We addressed this issue here by comparing a number of morphological measures of the cells, including area, perimeter, and elongation obtained from such a tessellation with identical measures extracted from direct imaging acquired by staining the cell membranes. After analyzing the shapes of 15,000 MDCK II epithelial cells under several conditions, we find that CMVT reasonably well reproduces many of the morphological properties of the tissue with an error that is between 10 and 15%. Moreover, cross-correlations between different morphological measures are reproduced qualitatively correctly by this method. However, all of the properties including the cell perimeters, number of neighbors, and anisotropy measures often suffer from systematic or size dependent errors. These discrepancies originate from the polygonal nature of the tessellation which sets the limits of the applicability of CMVT. PMID:27932987

  14. Morphology control of zinc regeneration for zinc-air fuel cell and battery

    NASA Astrophysics Data System (ADS)

    Wang, Keliang; Pei, Pucheng; Ma, Ze; Xu, Huachi; Li, Pengcheng; Wang, Xizhong

    2014-12-01

    Morphology control is crucial both for zinc-air batteries and for zinc-air fuel cells during zinc regeneration. Zinc dendrite should be avoided in zinc-air batteries and zinc pellets are yearned to be formed for zinc-air fuel cells. This paper is mainly to analyze the mechanism of shape change and to control the zinc morphology during charge. A numerical three-dimensional model for zinc regeneration is established with COMSOL software on the basis of ionic transport theory and electrode reaction electrochemistry, and some experiments of zinc regeneration are carried out. The deposition process is qualitatively analyzed by the kinetics Monte Carlo method to study the morphological change from the electrocrystallization point of view. Morphological evolution of deposited zinc under different conditions of direct currents and pulse currents is also investigated by simulation. The simulation shows that parametric variables of the flowing electrolyte, the surface roughness and the structure of the electrode, the charging current and mode affect morphological evolution. The uniform morphology of deposited zinc is attained at low current, pulsating current or hydrodynamic electrolyte, and granular morphology is obtained by means of an electrode of discrete columnar structure in combination with high current and flowing electrolyte.

  15. Morphological features (defects) in fuel cell membrane electrode assemblies

    NASA Astrophysics Data System (ADS)

    Kundu, S.; Fowler, M. W.; Simon, L. C.; Grot, S.

    Reliability and durability issues in fuel cells are becoming more important as the technology and the industry matures. Although research in this area has increased, systematic failure analysis, such as a failure modes and effects analysis (FMEA), are very limited in the literature. This paper presents a categorization scheme of causes, modes, and effects related to fuel cell degradation and failure, with particular focus on the role of component quality, that can be used in FMEAs for polymer electrolyte membrane (PEM) fuel cells. The work also identifies component defects imparted on catalyst-coated membranes (CCM) by manufacturing and proposes mechanisms by which they can influence overall degradation and reliability. Six major defects have been identified on fresh CCM materials, i.e., cracks, orientation, delamination, electrolyte clusters, platinum clusters, and thickness variations.

  16. Vertical and lateral morphology effects on solar cell performance for a thiophene–quinoxaline copolymer:PC 70BM blend

    DOE PAGES

    Hansson, Rickard; Ericsson, Leif K. E.; Holmes, Natalie P.; ...

    2015-02-13

    The distribution of electron donor and acceptor in the active layer is known to strongly influence the electrical performance of polymer solar cells for most of the high performance polymer:fullerene systems. The formulation of the solution from which the active layer is spincoated plays an important role in the quest for morphology control. We have studied how the choice of solvent and the use of small amounts of a low vapour pressure additive in the coating solution influence the film morphology and the solar cell performance for blends of poly[2,3-bis-(3-octyloxyphenyl)quinoxaline-5,8-diyl-alt-thiophene-2,5-diyl] (TQ1) and [6,6]-phenyl C71-butyric acid methyl ester (PC70BM). We havemore » investigated the lateral morphology using atomic force microscopy (AFM) and scanning transmission X-ray microscopy (STXM), the vertical morphology using dynamic secondary ion mass spectrometry (d-SIMS) and variable-angle spectroscopic ellipsometry (VASE), and the surface composition using near-edge X-ray absorption fine structure (NEXAFS). The lateral phase-separated domains observed in films spincoated from single solvents, increase in size with increasing solvent vapour pressure and decreasing PC70BM solubility, but are not observed when 1-chloronaphthalene (CN) is added. A strongly TQ1-enriched surface layer is formed in all TQ1:PC70BM blend films and rationalized by surface energy differences. The photocurrent and power conversion efficiency strongly increased upon the addition of CN, while the leakage current decreased by one to two orders of magnitude. The higher photocurrent correlates with the finer lateral structure and stronger TQ1-enrichment at the interface with the electron-collecting electrode. This indicates that the charge transport and collection are not hindered by this polymer-enriched surface layer. Neither the open-circuit voltage nor the series resistance of the devices are sensitive to the differences in morphology.« less

  17. Three-dimensional counting of morphologically normal human red blood cells via digital holographic microscopy

    NASA Astrophysics Data System (ADS)

    Yi, Faliu; Moon, Inkyu; Lee, Yeon H.

    2015-01-01

    Counting morphologically normal cells in human red blood cells (RBCs) is extremely beneficial in the health care field. We propose a three-dimensional (3-D) classification method of automatically determining the morphologically normal RBCs in the phase image of multiple human RBCs that are obtained by off-axis digital holographic microscopy (DHM). The RBC holograms are first recorded by DHM, and then the phase images of multiple RBCs are reconstructed by a computational numerical algorithm. To design the classifier, the three typical RBC shapes, which are stomatocyte, discocyte, and echinocyte, are used for training and testing. Nonmain or abnormal RBC shapes different from the three normal shapes are defined as the fourth category. Ten features, including projected surface area, average phase value, mean corpuscular hemoglobin, perimeter, mean corpuscular hemoglobin surface density, circularity, mean phase of center part, sphericity coefficient, elongation, and pallor, are extracted from each RBC after segmenting the reconstructed phase images by using a watershed transform algorithm. Moreover, four additional properties, such as projected surface area, perimeter, average phase value, and elongation, are measured from the inner part of each cell, which can give significant information beyond the previous 10 features for the separation of the RBC groups; these are verified in the experiment by the statistical method of Hotelling's T-square test. We also apply the principal component analysis algorithm to reduce the dimension number of variables and establish the Gaussian mixture densities using the projected data with the first eight principal components. Consequently, the Gaussian mixtures are used to design the discriminant functions based on Bayesian decision theory. To improve the performance of the Bayes classifier and the accuracy of estimation of its error rate, the leaving-one-out technique is applied. Experimental results show that the proposed method can

  18. Three-dimensional numerical model of cell morphology during migration in multi-signaling substrates.

    PubMed

    Mousavi, Seyed Jamaleddin; Doweidar, Mohamed Hamdy

    2015-01-01

    Cell Migration associated with cell shape changes are of central importance in many biological processes ranging from morphogenesis to metastatic cancer cells. Cell movement is a result of cyclic changes of cell morphology due to effective forces on cell body, leading to periodic fluctuations of the cell length and cell membrane area. It is well-known that the cell can be guided by different effective stimuli such as mechanotaxis, thermotaxis, chemotaxis and/or electrotaxis. Regulation of intracellular mechanics and cell's physical interaction with its substrate rely on control of cell shape during cell migration. In this notion, it is essential to understand how each natural or external stimulus may affect the cell behavior. Therefore, a three-dimensional (3D) computational model is here developed to analyze a free mode of cell shape changes during migration in a multi-signaling micro-environment. This model is based on previous models that are presented by the same authors to study cell migration with a constant spherical cell shape in a multi-signaling substrates and mechanotaxis effect on cell morphology. Using the finite element discrete methodology, the cell is represented by a group of finite elements. The cell motion is modeled by equilibrium of effective forces on cell body such as traction, protrusion, electrostatic and drag forces, where the cell traction force is a function of the cell internal deformations. To study cell behavior in the presence of different stimuli, the model has been employed in different numerical cases. Our findings, which are qualitatively consistent with well-known related experimental observations, indicate that adding a new stimulus to the cell substrate pushes the cell to migrate more directionally in more elongated form towards the more effective stimuli. For instance, the presence of thermotaxis, chemotaxis and electrotaxis can further move the cell centroid towards the corresponding stimulus, respectively, diminishing the

  19. Development of High-Antifouling PPSU Ultrafiltration Membrane by Using Compound Additives: Preparation, Morphologies, and Filtration Resistant Properties

    PubMed Central

    Liu, Jie; Zhong, Zhencheng; Ma, Rui; Zhang, Weichen; Li, Jiding

    2016-01-01

    In this study, flat sheet asymmetric polyphenylsulfone (PPSU) ultrafiltration membranes with enhanced antifouling properties were prepared with a non-solvent induced phase separation (NIPS) method through compound additives containing a polymeric pore-forming agent, a small molecular non-solvent and a surfactant. The formation processes of the porous asymmetric membranes with different kinds of additives were studied in detail, and the microstructure controllable preparation of membrane was achieved by establishing a bridge between the membrane preparation parameters and separation performances. All prepared membranes were characterized by using a scanning electron microscope (SEM), contact angle analysis, porosity, maximum pore size, water and BSA solution permeability studies. The performance efficiency of the membrane was evaluated by using BSA as a model foulant in terms of permeability, solute rejection (R), Rm (membrane inherent resistance), Rc (cake layer resistance), and Rp (pore plugging resistance). The results showed that when the compound additives were used, the inter-connected pores were observed, maximum pore size, contact angle and membrane filtration resistance decreased, while the porosity increased. When PVP compound additives were added, the water flux increased from 80.4 to 148.1 L/(m2·h), the BSA rejection increased from 53.2% to 81.5%. A similar trend was observed for membranes with added PEG compound additives; the water flux and BSA rejection simultaneously increased. The filtration resistance decreased as a result of compound additives. The uniformity of membrane and the number of effective pores could be enhanced by adding compound additives through the cooperation of different additives. PMID:27338487

  20. Development of High-Antifouling PPSU Ultrafiltration Membrane by Using Compound Additives: Preparation, Morphologies, and Filtration Resistant Properties.

    PubMed

    Liu, Jie; Zhong, Zhencheng; Ma, Rui; Zhang, Weichen; Li, Jiding

    2016-06-21

    In this study, flat sheet asymmetric polyphenylsulfone (PPSU) ultrafiltration membranes with enhanced antifouling properties were prepared with a non-solvent induced phase separation (NIPS) method through compound additives containing a polymeric pore-forming agent, a small molecular non-solvent and a surfactant. The formation processes of the porous asymmetric membranes with different kinds of additives were studied in detail, and the microstructure controllable preparation of membrane was achieved by establishing a bridge between the membrane preparation parameters and separation performances. All prepared membranes were characterized by using a scanning electron microscope (SEM), contact angle analysis, porosity, maximum pore size, water and BSA solution permeability studies. The performance efficiency of the membrane was evaluated by using BSA as a model foulant in terms of permeability, solute rejection (R), Rm (membrane inherent resistance), Rc (cake layer resistance), and Rp (pore plugging resistance). The results showed that when the compound additives were used, the inter-connected pores were observed, maximum pore size, contact angle and membrane filtration resistance decreased, while the porosity increased. When PVP compound additives were added, the water flux increased from 80.4 to 148.1 L/(m²·h), the BSA rejection increased from 53.2% to 81.5%. A similar trend was observed for membranes with added PEG compound additives; the water flux and BSA rejection simultaneously increased. The filtration resistance decreased as a result of compound additives. The uniformity of membrane and the number of effective pores could be enhanced by adding compound additives through the cooperation of different additives.

  1. Effect of a phytogenic feed additive on performance, ovarian morphology, serum lipid parameters and egg sensory quality in laying hen

    PubMed Central

    Saki, Ali Asghar; Aliarabi, Hassan; Hosseini Siyar, Sayed Ali; Salari, Jalal; Hashemi, Mahdi

    2014-01-01

    This present study was conducted to evaluate the effects of dietary inclusion of 4, 8 and 12 g kg-1 phytogenic feed additives mixture on performance, egg quality, ovary parameters, serum biochemical parameters and yolk trimethylamine level in laying hens. The results of experiment have shown that egg weight was increased by supplementation of 12 g kg-1 feed additive whereas egg production, feed intake and feed conversion ratio (FCR) were not significantly affected. There were no significant differences in egg quality parameters by supplementation of phytogenic feed additive, whereas yolk trimethylamine level was decreased as the feed additive level increased. The sensory evaluation parameters did not differ significantly. No significant differences were found in serum cholesterol and triglyceride levels between the treatments but low- and high-density lipoprotein were significantly increased. Number of small follicles and ovary weight were significantly increased by supplementation of 12 g kg-1 feed additive. Overall, dietary supplementation of polyherbal additive increased egg weigh, improved ovary characteristics and declined yolk trimethylamine level. PMID:25610580

  2. Effect of a phytogenic feed additive on performance, ovarian morphology, serum lipid parameters and egg sensory quality in laying hen.

    PubMed

    Saki, Ali Asghar; Aliarabi, Hassan; Hosseini Siyar, Sayed Ali; Salari, Jalal; Hashemi, Mahdi

    2014-01-01

    This present study was conducted to evaluate the effects of dietary inclusion of 4, 8 and 12 g kg(-1) phytogenic feed additives mixture on performance, egg quality, ovary parameters, serum biochemical parameters and yolk trimethylamine level in laying hens. The results of experiment have shown that egg weight was increased by supplementation of 12 g kg(-1) feed additive whereas egg production, feed intake and feed conversion ratio (FCR) were not significantly affected. There were no significant differences in egg quality parameters by supplementation of phytogenic feed additive, whereas yolk trimethylamine level was decreased as the feed additive level increased. The sensory evaluation parameters did not differ significantly. No significant differences were found in serum cholesterol and triglyceride levels between the treatments but low- and high-density lipoprotein were significantly increased. Number of small follicles and ovary weight were significantly increased by supplementation of 12 g kg(-1) feed additive. Overall, dietary supplementation of polyherbal additive increased egg weigh, improved ovary characteristics and declined yolk trimethylamine level.

  3. In situ visualization of intracellular morphology of epidermal cells using stimulated Raman scattering microscopy

    NASA Astrophysics Data System (ADS)

    Egawa, Mariko; Tokunaga, Kyoya; Hosoi, Junichi; Iwanaga, Shinya; Ozeki, Yasuyuki

    2016-08-01

    Visualization of epidermal cells is important because the differentiation patterns of keratinocytes (KCs) are considered to be related to the functions and condition of skin. Optical microscopy has been widely used to investigate epidermal cells, but its applicability is still limited because of the need for sample fixation and staining. Here, we report our staining-free observation of epidermal cells in both tissue and culture by stimulated Raman scattering (SRS) microscopy that provides molecular vibrational contrast. SRS allowed us to observe a variety of cellular morphologies in skin tissue, including ladder-like structures in the spinous layer, enucleation of KCs in the granular layer, and three-dimensional cell column structures in the stratum corneum. We noticed that some cells in the spinous layer had a brighter signal in the cytoplasm than KCs. To examine the relevance of the observation of epidermal layers, we also observed cultured epidermal cells, including KCs at various differentiation stages, melanocytes, and Langerhans cell-like cells. Their SRS images also demonstrated various morphologies, suggesting that the morphological differences observed in tissue corresponded to the cell lineage. These results indicate the possible application of SRS microscopy to dermatological investigation of cell lineages and types in the epidermis by cellular-level analysis.

  4. Morphological alterations of Vero cell exposed to coplanar PCB 126 and noncoplanar PCB 153.

    PubMed

    Shen, Kaili; Shen, Chaofeng; Chen, Lei; Chen, Xincai; Chen, Yingxu

    2012-01-01

    Polychlorinated biphenyls (PCBs) are widespread, persistent environmental contaminants that display a complex spectrum of toxicological properties. Exposure to PCBs has been associated with morphological anomalies in cell cultures. However, most mechanistic studies of PCBs' toxic activity have been focused on coplanar congeners. It is of importance to determine whether PCB treatment would influence cell configuration and whether these changes would depend on the structural characteristics of PCBs. In this study, we investigated cell morphological alteration in Vero cell cultures after exposure to coplanar PCB 126 and noncoplanar PCB 153. The survival of Vero cells was measured through the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) test. Cytotoxicity results suggested that PCB congeners had a toxic, antiproliferative effect on Vero cells. Morphological studies described structural modifications and provided evidence that apoptosis might be the main cell death pathway in PCB 153-treated cells. The comparison between PCB 126 and PCB 153 indicated that the cell death mechanisms involved in coplanar or noncoplanar PCB congener exposure were different in Vero cells.

  5. Distinctive Features of the Human Marginal Zone and Cajal–Retzius Cells: Comparison of Morphological and Immunocytochemical Features at Midgestation

    PubMed Central

    Tkachenko, Lyubov A.; Zykin, Pavel A.; Nasyrov, Ruslan A.; Krasnoshchekova, Elena I.

    2016-01-01

    Despite a long history of research of cortical marginal zone (MZ) organization and development, a number of issues remain unresolved. One particular issue is the problem of Cajal–Retzius cells (C–R) identification. It is currently based on morphology and Reelin expression. The aim of this research is to investigate MZ cytoarchitectonics and Reelin-producing cells morphotypes in the superior temporal, pre- and postcentral cortex at GW24–26. We used Reelin (Reln) as the marker for C–R cells and microtubule-associated protein 2 (MAP2) and neurofilament heavy chain protein (N200) as markers of neuronal maturation. The MZ of all of the investigated areas had the distinct cytoarchitectonic of alternating cell sparse (MZP, SR) and cell dense (SGL, DGL) layers. The distribution of the neuromarkers across the MZ also showed layer specificity. MAP2-positive cells were only found in the SGL. N200 and Reelin-positive neurons in the MZP. N200-positive processes were forming a plexus at the DGL level. All of the N200-positive neurons found were in the MZP and had distinctive morphological features of C–R cells. All of the N200-positive neurons in MZ were also positive for Reelin, whereas MAP2-positive cells lack Reelin. Thus, the joint use of two immunomarkers allowed us to discern the C–R cells based on their morphotype and neurochemistry and indicate that the Reelin-positive cells of MZ at 24–26 GW were morphologically C–R cells. In the current study, we identified three C–R cells morphotypes. Using a 3D reconstruction, we made sure that all of them belonged to the single morphotype of triangular C–R cells. This approach will allow future studies to separate C–R cells from other Reelin-producing neurons which appear at later corticogenesis stages. In addition, our findings support the assumption that a plexus could be formed not only with C–R cells processes but also possibly by other cell processes by the poorly researched DGL, which is only allocated

  6. Three-Dimensional Numerical Model of Cell Morphology during Migration in Multi-Signaling Substrates

    PubMed Central

    Mousavi, Seyed Jamaleddin; Hamdy Doweidar, Mohamed

    2015-01-01

    Cell Migration associated with cell shape changes are of central importance in many biological processes ranging from morphogenesis to metastatic cancer cells. Cell movement is a result of cyclic changes of cell morphology due to effective forces on cell body, leading to periodic fluctuations of the cell length and cell membrane area. It is well-known that the cell can be guided by different effective stimuli such as mechanotaxis, thermotaxis, chemotaxis and/or electrotaxis. Regulation of intracellular mechanics and cell’s physical interaction with its substrate rely on control of cell shape during cell migration. In this notion, it is essential to understand how each natural or external stimulus may affect the cell behavior. Therefore, a three-dimensional (3D) computational model is here developed to analyze a free mode of cell shape changes during migration in a multi-signaling micro-environment. This model is based on previous models that are presented by the same authors to study cell migration with a constant spherical cell shape in a multi-signaling substrates and mechanotaxis effect on cell morphology. Using the finite element discrete methodology, the cell is represented by a group of finite elements. The cell motion is modeled by equilibrium of effective forces on cell body such as traction, protrusion, electrostatic and drag forces, where the cell traction force is a function of the cell internal deformations. To study cell behavior in the presence of different stimuli, the model has been employed in different numerical cases. Our findings, which are qualitatively consistent with well-known related experimental observations, indicate that adding a new stimulus to the cell substrate pushes the cell to migrate more directionally in more elongated form towards the more effective stimuli. For instance, the presence of thermotaxis, chemotaxis and electrotaxis can further move the cell centroid towards the corresponding stimulus, respectively, diminishing the

  7. Investigation of cell morphology for disease diagnostics via high content screening

    NASA Astrophysics Data System (ADS)

    Khatau, Shyam

    2013-03-01

    Ninety percent of all cancer-related deaths are caused by metastatic disease, i.e. the spreading of a subset of cells from a primary tumor in an organ to distal sites in other organs. Understanding this progression from localized to metastatic disease is essential for further developing effective therapeutic and treatment strategies. However, despite research efforts, no distinct genetic, epigenetic, or proteomic signature of cancer metastasis has been identified so far. Metastasis is a physical event: through invasion and migration through the dense, tortuous stromal matrix, intravasation, shear forces of blood flow, successful re-attachment to blood vessel walls, migration, the colonization of a distal site, and, finally, reactivation following dormancy, metastatic cells may share precise physical properties. Cell morphology is the most direct physical property that can be measured. In this work, we develop a high throughput cell phenotyping process and investigate the morphological signature of primary tumor cells and liver metastatic pancreatic cancer cells.

  8. Induction of morphological changes in death-induced cancer cells monitored by holographic microscopy.

    PubMed

    El-Schich, Zahra; Mölder, Anna; Tassidis, Helena; Härkönen, Pirkko; Falck Miniotis, Maria; Gjörloff Wingren, Anette

    2015-03-01

    We are using the label-free technique of holographic microscopy to analyze cellular parameters including cell number, confluence, cellular volume and area directly in the cell culture environment. We show that death-induced cells can be distinguished from untreated counterparts by the use of holographic microscopy, and we demonstrate its capability for cell death assessment. Morphological analysis of two representative cell lines (L929 and DU145) was performed in the culture flasks without any prior cell detachment. The two cell lines were treated with the anti-tumour agent etoposide for 1-3days. Measurements by holographic microscopy showed significant differences in average cell number, confluence, volume and area when comparing etoposide-treated with untreated cells. The cell volume of the treated cell lines was initially increased at early time-points. By time, cells decreased in volume, especially when treated with high doses of etoposide. In conclusion, we have shown that holographic microscopy allows label-free and completely non-invasive morphological measurements of cell growth, viability and death. Future applications could include real-time monitoring of these holographic microscopy parameters in cells in response to clinically relevant compounds.

  9. Morphologic Plasticity and Periodicity: Porcine Cerebral Microvascular Cells in Culture

    DTIC Science & Technology

    1990-02-01

    The cells were subcultured no Bandeiraea Simplicifolia (BSA-1), Ulex europaeus ( UEA -1), earlier than 7 d by treatment with trypsin-EDTA. The Triticum...EP013, DdCUMENTATION ,AG,.) I FILE COPY! * lb. RESTRICTIVE MARKINGS 2 AA 967 -- 3. DISTRIBUTIONIAVAILAaITY OFROT _2 967 Approved for public release...ORGANIZATION 6b. OFFICE SYMBOL 7a. NAME OF MONITORING ORGANIZATION Naval Medical ResearchI (if applicable) I INaval Medical Command 6-. ADDRESS (Cty

  10. Persistence of sister chromatid exchanges and in vitro morphological transformation of Syrian hamster fetal cells by chemical and physical carcinogens

    SciTech Connect

    Popescu, N.C.; Amsbaugh, S.C.; DiPaolo, J.A.

    1985-11-01

    The induction of neoplastic cell transformation is closely associated with DNA alterations which occur shortly after carcinogen exposure. Sister chromatid exchange (SCE) formation is a sensitive indicator of carcinogen-DNA interaction and correlates with the induction of morphological cell transformation. The persistence of lesions generating SCE produced by chemical and physical carcinogens and its relevance to the induction of morphologic transformation was evaluated in coordinated experiments with cultured Syrian hamster fetal cells (HFC). Exponentially growing HFC were exposed for 1 h to benzo(a)pyrene (BP), methyl-methanesulfonate (MMS), cis-platinum (II) diaminedichloride (cis Pt II), N-methyl-N'-nitrosourea (MNU), mitomycin C (MMC), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), N-acetoxy-2-fluorenyl-acetamide (AcAAF) or u.v. light irradiated. SCE analysis demonstrates that for a period of 48 h after carcinogen exposure, during which time the cells undergo at least four replicative cycles, DNA damage generating SCE induced by all chemical carcinogens either persisted or was partially removed, whereas u.v.-induced lesions were completely removed. An elevated SCE frequency persisted after two additional cell cycles after treatment with BP, AcAAF or MMC without increased cell lethality as compared to other carcinogens whose lesions were completely eliminated during the same period.

  11. Morphological and physiological changes induced by high hydrostatic pressure in exponential- and stationary-phase cells of Escherichia coli: relationship with cell death.

    PubMed

    Mañas, Pilar; Mackey, Bernard M

    2004-03-01

    The relationship between a loss of viability and several morphological and physiological changes was examined with Escherichia coli strain J1 subjected to high-pressure treatment. The pressure resistance of stationary-phase cells was much higher than that of exponential-phase cells, but in both types of cell, aggregation of cytoplasmic proteins and condensation of the nucleoid occurred after treatment at 200 MPa for 8 min. Although gross changes were detected in these cellular structures, they were not related to cell death, at least for stationary-phase cells. In addition to these events, exponential-phase cells showed changes in their cell envelopes that were not seen for stationary-phase cells, namely physical perturbations of the cell envelope structure, a loss of osmotic responsiveness, and a loss of protein and RNA to the extracellular medium. Based on these observations, we propose that exponential-phase cells are inactivated under high pressure by irreversible damage to the cell membrane. In contrast, stationary-phase cells have a cytoplasmic membrane that is robust enough to withstand pressurization up to very intense treatments. The retention of an intact membrane appears to allow the stationary-phase cell to repair gross changes in other cellular structures and to remain viable at pressures that are lethal to exponential-phase cells.

  12. New paradigm to assess brain cell morphology by diffusion-weighted MR spectroscopy in vivo

    PubMed Central

    Palombo, Marco; Ligneul, Clémence; Najac, Chloé; Le Douce, Juliette; Flament, Julien; Escartin, Carole; Hantraye, Philippe; Brouillet, Emmanuel; Bonvento, Gilles; Valette, Julien

    2016-01-01

    The brain is one of the most complex organs, and tools are lacking to assess its cellular morphology in vivo. Here we combine original diffusion-weighted magnetic resonance (MR) spectroscopy acquisition and novel modeling strategies to explore the possibility of quantifying brain cell morphology noninvasively. First, the diffusion of cell-specific metabolites is measured at ultra-long diffusion times in the rodent and primate brain in vivo to observe how cell long-range morphology constrains metabolite diffusion. Massive simulations of particles diffusing in synthetic cells parameterized by morphometric statistics are then iterated to fit experimental data. This method yields synthetic cells (tentatively neurons and astrocytes) that exhibit striking qualitative and quantitative similarities with histology (e.g., using Sholl analysis). With our approach, we measure major interspecies difference regarding astrocytes, whereas dendritic organization appears better conserved throughout species. This work suggests that the time dependence of metabolite diffusion coefficient allows distinguishing and quantitatively characterizing brain cell morphologies noninvasively. PMID:27226303

  13. MIRO1 influences the morphology and intracellular distribution of mitochondria during embryonic cell division in Arabidopsis.

    PubMed

    Yamaoka, Shohei; Nakajima, Masaki; Fujimoto, Masaru; Tsutsumi, Nobuhiro

    2011-02-01

    Regulating the morphology and intracellular distribution of mitochondria is essential for embryo development in animals. However, the importance of such regulation is not clearly defined in plants. The evolutionarily conserved Miro proteins are known to be involved in the regulation of mitochondrial morphology and motility. We previously demonstrated that MIRO1, an Arabidopsis thaliana orthologue of the Miro protein, is required for embryogenesis. An insertional mutation in the MIRO1 gene causes arrest of embryonic cell division, leading to abortion of the embryo at an early stage. Here we investigated the role of MIRO1 in the regulation of mitochondrial behaviour in egg cells and early-stage embryos using GFP-labeled mitochondria. Two-photon laser scanning microscopy revealed that, in miro1 mutant egg cells, mitochondria are abnormally enlarged, although egg cell formation is nearly unaffected. After fertilization and subsequent zygotic cell division, the homozygous miro1 mutant two-celled embryo contained a significantly reduced number of mitochondria in its apical cell compared with the wild type, suggesting that the miro1 mutation inhibits proper intracellular distribution of mitochondria, leading to an arrest of embryonic cell division. Our findings suggest that proper mitochondrial morphology and intracellular distribution are maintained by MIRO1 and are vital for embryonic cell division.

  14. Engineering Cyanobacterial Cell Morphology for Enhanced Recovery and Processing of Biomass.

    PubMed

    Jordan, Adam; Chandler, Jenna; MacCready, Joshua S; Huang, Jingcheng; Osteryoung, Katherine W; Ducat, Daniel C

    2017-02-24

    Cyanobacteria are emerging as alternative crop species for the production of fuels, chemicals, and biomass. Yet, the success of these microbes depends upon the development of cost-effective technologies that permit scaled cultivation and cell harvesting. Here, we investigate the feasibility of engineering cell morphology in order to improve biomass recovery and decrease energetic costs associated with lysing cyanobacterial cells. Specifically, we modify the levels of Min system proteins in Synechococcus elongatus sp. PCC 7942. The Min system has established functions in controlling cell division by regulating assembly of FtsZ, a tubulin-like protein required to define the bacterial division plane. We show that altering expression of two FtsZ-regulatory proteins, MinC and Cdv3, permits control over cell morphology by disrupting FtsZ localization and cell division, without preventing continued cell growth. By varying the expression of these proteins, we can tune the length of cyanobacterial cells across a broad dynamic range: anywhere from a ∼20% increased length relative to wildtype to near-millimeter lengths. Highly elongated cells exhibit increased rates of sedimentation under low centrifugal forces or by gravity-assisted settling. Furthermore, hyperelongated cells are also more susceptible to lysis through the application of mild physical stress. Collectively, these results demonstrate a novel approach towards decreasing harvesting and processing costs associated with mass cyanobacterial cultivation through altering morphology at the cellular level.Importance: We show that the cell length of a model cyanobacterial species can be programmed through the rational manipulation of expression of protein factors that suppress cell division. In some instances, we are able to increase the size of these cells to near millimeter lengths through this approach. The resulting elongated cells have favorable properties with regard to cell harvesting and lysis. Furthermore

  15. Imaging Nuclear Morphology and Organization in Cleared Plant Tissues Treated with Cell Cycle Inhibitors.

    PubMed

    de Souza Junior, José Dijair Antonino; de Sa, Maria Fatima Grossi; Engler, Gilbert; Engler, Janice de Almeida

    2016-01-01

    Synchronization of root cells through chemical treatment can generate a large number of cells blocked in specific cell cycle phases. In plants, this approach can be employed for cell suspension cultures and plant seedlings. To identify plant cells in the course of the cell cycle, especially during mitosis in meristematic tissues, chemical inhibitors can be used to block cell cycle progression. Herein, we present a simplified and easy-to-apply protocol to visualize mitotic figures, nuclei morphology, and organization in whole Arabidopsis root apexes. The procedure is based on tissue clearing, and fluorescent staining of nuclear DNA with DAPI. The protocol allows carrying out bulk analysis of nuclei and cell cycle phases in root cells and will be valuable to investigate mutants like overexpressing lines of genes disturbing the plant cell cycle.

  16. Morphology of retinal ganglion cells in the flying fox (Pteropus scapulatus): a lucifer yellow investigation.

    PubMed

    Dann, J F; Buhl, E H

    1990-11-15

    The morphology of retinal ganglion cells was determined in megachiroptera, commonly known as flying foxes. Retinal ganglion cells were intracellularly injected with the fluorescent dye Lucifer yellow in fixed retinae from adult little red flying foxes (Pteropus scapulatus) captured in their natural habitat. Ganglion cells closely resembled the three main classes of cat retinal ganglion cells, and therefore were classified into alpha-, beta-, and gamma-type cells. The size of the alpha- and beta-type somas and dendritic fields increased with increasing distance from the area centralis. However, this eccentricity dependence was not as pronounced as in the cat. The gamma-type cells were sub-divided into mono-, bi-, and diffusely stratified, in accordance with the ramification of their dendrites within the inner plexiform layer. The alpha- and beta-type cells were uni-stratified in either the sublamina of the inner plexiform layer closest to the ganglion cell layer or in that closest to the inner nuclear layer. These laminae correspond to those in the cat retina which contain the dendritic ramifications of ganglion cells whose central receptive fields respond best to onset of light (the "on-centre" cells), or to ganglion cells whose centres respond optimally to light being extinguished (the "off-centre" cells). Thus the flying fox retina contains a morphological correlate of the "on"/"off" dichotomy of alpha and beta cells in the cat retina. In general the flying fox retinal ganglion cells exhibit a degree of morphological complexity reminiscent of cat retinal cells and this may reflect similar functional properties.

  17. Nanomechanical clues from morphologically normal cervical squamous cells could improve cervical cancer screening

    NASA Astrophysics Data System (ADS)

    Geng, Li; Feng, Jiantao; Sun, Quanmei; Liu, Jing; Hua, Wenda; Li, Jing; Ao, Zhuo; You, Ke; Guo, Yanli; Liao, Fulong; Zhang, Youyi; Guo, Hongyan; Han, Jinsong; Xiong, Guangwu; Zhang, Lufang; Han, Dong

    2015-09-01

    Applying an atomic force microscope, we performed a nanomechanical analysis of morphologically normal cervical squamous cells (MNSCs) which are commonly used in cervical screening. Results showed that nanomechanical parameters of MNSCs correlate well with cervical malignancy, and may have potential in cancer screening to provide early diagnosis.Applying an atomic force microscope, we performed a nanomechanical analysis of morphologically normal cervical squamous cells (MNSCs) which are commonly used in cervical screening. Results showed that nanomechanical parameters of MNSCs correlate well with cervical malignancy, and may have potential in cancer screening to provide early diagnosis. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr03662c

  18. In-Depth Understanding of the Morphology-Performance Relationship in Polymer Solar Cells.

    PubMed

    Huang, Wenchao; Gann, Eliot; Cheng, Yi-Bing; McNeill, Christopher R

    2015-07-01

    It is well-established that thermal annealing optimizes the morphology and improves the efficiency of P3HT-based organic solar cells, but the effects of different cooling rates after annealing are not well understood. In this paper, we use a model system based on poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) to examine the relationship between morphology and device performance for annealing before (preannealing) and after (postannealing) the application of the electrode, with different cooling rates and in different device architectures. In the conventional structure, postannealing is confirmed to significantly enhance efficiency. The device prepared with a slow cooling rate (3.6%) shows a higher average power conversion efficiency than that prepared with a fast cooling rate (3.3%). The microstructural changes underlying this 10% increase in device performance and further effects of cooling rate, pre- and postannealing, and device architecture are comprehensively examined with a combination of synchrotron-based techniques, including grazing incidence wide-angle X-ray scattering, near-edge X-ray absorption fine structure spectroscopy, and X-ray photoelectron spectroscopy. The best device in the conventional architecture (postannealed with slow cooling rate) shows a more face-on orientation and narrower orientational distribution of P3HT crystallites. In addition, postannealing leads to PCBM diffusion toward the blend/top electrode interface. The enrichment of PCBM at the blend/top electrode interface plays a positive role in aiding electron collection at the electrode in the conventional structure, but it has a negative effect on the performance of the inverted structure, where hole collection at the top electrode instead is required. For this reason, in an inverted structure, preannealed films with slow cooling exhibit the best photovoltaic performance.

  19. Influence of USP laser radiation on cell morphology: HaCat and MG-63 cell lines for bone and soft tissue modelling in dentistry

    NASA Astrophysics Data System (ADS)

    Meister, Joerg; Schelle, Florian; Beier, Imke; Bourauel, Christoph; Frentzen, Matthias; Kraus, Dominik

    Due to the high intensities of USP laser radiation, the interaction with matter is always attended with a plasma formation. Therefore the surrounding tissue can be influenced by heat generation and additional light emission from the UV up to the near and mid infrared. In dentistry it is of importance that the treatment of bone and soft tissues, i.e. oral mucosa, with a USP laser should not cause any kind of morphological changes on the cell level leading to a delayed wound healing or cell mutation. HaCaT keratinocyte cells were used for epidermal (soft tissue) and MG-63 osteoblast-like cells for hard tissue (bone) modelling. Cell growing was realized on glas cover slips. Irradiation was carried out with a USP Nd:YVO4 laser having a center wavelength at 1064 nm. Based on the pulse duration of 8 ps and a pulse repetition rate of 500 kHz the laser emits an average power of 9 W. For efficiency testing of cell removal on glas cover slips, 1, 5, 25, 50 and 75 repetitions of the scanning pattern (scan loops) were used. Heat distribution during laser irradiation was measured with an infrared camera system. Subsequently haematoxylin staining and SEM investigations were used to analyse the morphological changes. Differences of cell removal efficiency were observed with repetitions <=25. Irradiated areas with repetitions >=50 were cell-free. Additionally, repetitions >=25 showed side effects for both cell lines. Cell destruction in both cell lines could be verified using the haematoxylin staining and the SEM pictures.

  20. Cellient™ automated cell block versus traditional cell block preparation: a comparison of morphologic features and immunohistochemical staining.

    PubMed

    Wagner, David G; Russell, Donna K; Benson, Jenna M; Schneider, Ashley E; Hoda, Rana S; Bonfiglio, Thomas A

    2011-10-01

    Traditional cell block (TCB) sections serve as an important diagnostic adjunct to cytologic smears but are also used today as a reliable preparation for immunohistochemical (IHC) studies. There are many ways to prepare a cell block and the methods continue to be revised. In this study, we compare the TCB with the Cellient™ automated cell block system. Thirty-five cell blocks were obtained from 16 benign and 19 malignant nongynecologic cytology specimens at a large university teaching hospital and prepared according to TCB and Cellient protocols. Cell block sections from both methods were compared for possible differences in various morphologic features and immunohistochemical staining patterns. In the 16 benign cases, no significant morphologic differences were found between the TCB and Cellient cell block sections. For the 19 malignant cases, some noticeable differences in the nuclear chromatin and cellularity were identified, although statistical significance was not attained. Immunohistochemical or special stains were performed on 89% of the malignant cases (17/19). Inadequate cellularity precluded full evaluation in 23% of Cellient cell block IHC preparations (4/17). Of the malignant cases with adequate cellularity (13/17), the immunohistochemical staining patterns from the different methods were identical in 53% of cases. The traditional and Cellient cell block sections showed similar morphologic and immunohistochemical staining patterns. The only significant difference between the two methods concerned the lower overall cell block cellularity identified during immunohistochemical staining in the Cellient cell block sections.

  1. Continuous lateral gradients in film morphology for position sensitive detection and organic solar cell optimization

    NASA Astrophysics Data System (ADS)

    Campoy-Quiles, M.; Randon, V.; Mróz, M. M.; Jarzaguet, M.; Garriga, M.; Cabanillas-González, J.

    2013-07-01

    We present a method to fabricate binary organic donor and acceptor blends exhibiting a controlled lateral gradient in morphology. Upon combining photometry, ellipsometry and Xray maps together with photoinduced absorption measurements, we show how the gradual exposure to solvent vapor results in a varying degree of polymer crystallinity for the polythiophene/soluble fullerene system along one direction. These morphologically graded samples are characterized by a spectral photoresponse that depends on the specific location in the area of the device where the light beam impinges, a property that stands as proof-of-concept for position sensitive detection. Moreover, we demonstrate that the development of graded morphologies is an effective one-step method which allows for fast performance optimization of organic solar cells. Finally, the appropriateness of eight different solvents for morphology control via vapor annealing is evaluated in a time-effective way using the advanced method, which helps to identify boiling point and solubility as the key processing parameters.

  2. Evaluation of the effects of Cimicifugae Rhizoma on the morphology and viability of mesenchymal stem cells

    PubMed Central

    JEONG, SU-HYEON; LEE, JI-EUN; KIM, BO-BAE; KO, YOUNGKYUNG; PARK, JUN-BEOM

    2015-01-01

    Cimicifugae Rhizoma is a traditional herbal medicine used to treat various diseases in Korea, China and Japan. Cimicifugae Rhizoma is primarily derived from Cimicifuga heracleifolia Komarov or Cimicifuga foetida Linnaeus. Cimicifugae Rhizoma has been used as an anti-inflammatory, analgesic and antipyretic remedy. The present study was performed to evaluate the extracts of Cimicifugae Rhizoma on the morphology and viability of human stem cells derived from gingiva. Stem cells derived from gingiva were grown in the presence of Cimicifugae Rhizoma at final concentrations that ranged from 0.001 to 1,000 µg/ml. The morphology of the cells was viewed under an inverted microscope and the analysis of cell proliferation was performed using a Cell Counting kit-8 (CCK-8) assay on days 1, 3, 5 and 7. Under an optical microscope, the control cells exhibited a spindle-shaped, fibroblast-like morphology. The shapes of the cells in the groups treated with 0.001, 0.01, 0.1, 1 and 10 µg/ml Cimicifugae Rhizoma were similar to the shapes in the control group. Significant alterations in morphology were noted in the 100 and 1,000 µg/ml groups when compared with the control group. The cells in the 100 and 1,000 µg/ml groups were rounder, and fewer cells were present. The cultures that were grown in the presence of Cimicifugae Rhizoma at a concentration of 0.001 µg/ml on day 1 had an increased CCK-8 value. The cultures grown in the presence of Cimicifugae Rhizoma at a concentration of 10 µg/ml on day 7 had a reduced CCK-8 value. Within the limits of this study, Cimicifugae Rhizoma influenced the viability of stem cells derived from the gingiva, and its direct application onto oral tissues may have adverse effects at high concentrations. The concentration and application time of Cimicifugae Rhizoma should be meticulously controlled to obtain optimal results. PMID:26622366

  3. Understanding the Role of Additives in Improving the Performance of Polymer:Fullerene Bulk Heterojunction Solar Cells

    NASA Astrophysics Data System (ADS)

    Chen, Wei

    2014-03-01

    Solar cells based on the polymer:fullerene bulk heterojunction (BHJ) represent one of the most promising technologies for next-generation solar energy conversion due to their low-cost and scalability. In the last fifteen years, research efforts have led to organic photovoltaic (OPV) devices with power conversion efficiencies (PCEs) ~ 12%, but these values are still insufficient for the devices to become widely marketable. To further improve solar cell performance, a thorough understanding of the complex processing-structure-performance relationships in OPV devices is required. Recently, the use of processing additives have been proved to be one of the most effective methods to tune the nanomorphology of polymer:fullerene active layer, as the incorporation of a small percentage of solvent additives results in a nearly doubling of device efficiency. However, the physics behind these improved performances by processing additives still remains unclear. In this work, by taking advantage of resonant soft x-ray scattering (RSoXS) and energy-filtered transmission electron microscopy (EFTEM), we have determined that the solvent additives induce the change in the formation mechanism of polymer:fullerene nanomorphologies in the process of film casting. Progress established in the course of these studies on structural and morphological characterizations will serve as the foundation for further improving the efficiency of polymer solar cells to realize their large-scale commercial use.

  4. Automatic Robust Neurite Detection and Morphological Analysis of Neuronal Cell Cultures in High-content Screening

    PubMed Central

    Wu, Chaohong; Schulte, Joost; Sepp, Katharine J.; Littleton, J. Troy

    2011-01-01

    Cell-based high content screening (HCS) is becoming an important and increasingly favored approach in therapeutic drug discovery and functional genomics. In HCS, changes in cellular morphology and biomarker distributions provide an information-rich profile of cellular responses to experimental treatments such as small molecules or gene knockdown probes. One obstacle that currently exists with such cell-based assays is the availability of image processing algorithms that are capable of reliably and automatically analyzing large HCS image sets. HCS images of primary neuronal cell cultures are particularly challenging to analyze due to complex cellular morphology. Here we present a robust method for quantifying and statistically analyzing the morphology of neuronal cells in HCS images. The major advantages of our method over existing software lie in its capability to correct non-uniform illumination using the contrast-limited adaptive histogram equalization method; segment neuromeres using Gabor-wavelet texture analysis; and detect faint neurites by a novel phase-based neurite extraction algorithm that is invariant to changes in illumination and contrast and can accurately localize neurites. Our method was successfully applied to analyze a large HCS image set generated in a morphology screen for polyglutamine-mediated neuronal toxicity using primary neuronal cell cultures derived from embryos of a Drosophila Huntington’s Disease (HD) model. PMID:20405243

  5. Morphology Evolution of High Efficiency Perovskite Solar Cells via Vapor Induced Intermediate Phases.

    PubMed

    Zuo, Lijian; Dong, Shiqi; De Marco, Nicholas; Hsieh, Yao-Tsung; Bae, Sang-Hoon; Sun, Pengyu; Yang, Yang

    2016-12-07

    Morphology is critical component to achieve high device performance hybrid perovskite solar cells. Here, we develop a vapor induced intermediate phase (VIP) strategy to manipulate the morphology of perovskite films. By exposing the perovskite precursor films to different saturated solvent vapor atmospheres, e.g., dimethylformamide and dimethylsufoxide, dramatic film morphological evolution occurs, associated with the formation of different intermediate phases. We observe that the crystallization kinetics is significantly altered due to the formation of these intermediate phases, yielding highly crystalline perovskite films with less defect states and high carrier lifetimes. The perovskite solar cells with the reconstructed films exhibits the highest power conversion efficiency (PCE) up to 19.2% under 1 sun AM 1.5G irradiance, which is among the highest planar heterojunction perovskite solar cells. Also, the perovskite solar cells with VIP processing shows less hysteresis behavior and a stabilized power output over 18%. Our work opens up a new direction for morphology control through intermediate phase formation, and paves the way toward further enhancing the device performances of perovskite solar cells.

  6. Morphological study of a connexin 43-GFP reporter mouse highlights glial heterogeneity, amacrine cells, and olfactory ensheathing cells.

    PubMed

    Theofilas, Panos; Steinhäuser, Christian; Theis, Martin; Derouiche, Amin

    2017-03-30

    Connexin 43 (Cx43) is the main astrocytic connexin and forms the basis of the glial syncytium. The morphology of connexin-expressing cells can be best studied in transgenic mouse lines expressing cytoplasmic fluorescent reporters, since immunolabeling the plaques can obscure the shapes of the individual cells. The Cx43kiECFP mouse generated by Degen et al. (FASEBJ 26:4576, 2012) expresses cytosolic ECFP and has previously been used to establish that Cx43 may not be expressed by all astrocytes within a population, and this can vary in a region-dependent way. To establish this mouse line as a tool for future astrocyte and connexin research, we sought to consolidate reporter authenticity, studying cell types and within-region population heterogeneity. Applying anti-GFP, all cell types related to astroglia were positive-namely, protoplasmic astrocytes in the hippocampus, cortex, thalamus, spinal cord, olfactory bulb, cerebellum with Bergmann glia and astrocytes also in the molecular layer, and retinal Müller cells and astrocytes. Labeled cell types further comprise white matter astrocytes, olfactory ensheathing cells, radial glia-like stem cells, retinal pigment epithelium cells, ependymal cells, and meningeal cells. We furthermore describe a retinal Cx43-expressing amacrine cell morphologically reminiscent of ON-OFF wide-field amacrine cells, representing the first example of a mammalian CNS neuron-expressing Cx43 protein. In double staining with cell type-specific markers (GFAP, S100ß, glutamine synthetase), Cx43 reporter expression in the hippocampus and cortex was restricted to GFAP(+) astrocytes. Altogether, this mouse line is a highly reliable tool for studies of Cx43-expressing CNS cells and astroglial cell morphology. © 2017 Wiley Periodicals, Inc.

  7. A study on the effect of the polymeric additive HPMC on morphology and polymorphism of ortho-aminobenzoic acid crystals

    NASA Astrophysics Data System (ADS)

    Simone, E.; Cenzato, M. V.; Nagy, Z. K.

    2016-07-01

    In the present study, the effect of Hydroxy Propyl Methyl Cellulose (HPMC) on the crystallization of ortho-aminobenzoic acid (OABA) was investigated by seeded and unseeded cooling crystallization experiments. The influence of HPMC on the induction time, crystal shape of Forms I and II of OABA and the polymorphic transformation time was studied. Furthermore, the capability of HPMC to inhibit growth of Form I was evaluated quantitatively and modeled using population balance equations (PBE) solved with the method of moments. The additive was found to strongly inhibit nucleation and growth of Form I as well as to increase the time for the polymorphic transformation from Form II to I. Solvent was also found to influence the shape of Form I crystals at equal concentrations of HPMC. In situ process analytical technology (PAT) tools, including Raman spectroscopy, focused beam reflectance measurement (FBRM) and attenuated total reflectance (ATR) UV-vis spectroscopy were used in combination with off-line techniques, such as optical microscopy, scanning electron microscopy (SEM), Raman spectroscopy, Malvern Mastersizer and differential scanning calorimetry (DSC) to study the crystals produced. The results illustrate how shape, size and stability of the two polymorphs of OABA can be controlled and tailored using a polymeric additive.

  8. A Mechanistic Understanding of a Binary Additive System to Synergistically Boost Efficiency in All-Polymer Solar Cells

    PubMed Central

    Kim, Yu Jin; Ahn, Sunyong; Wang, Dong Hwan; Park, Chan Eon

    2015-01-01

    All-polymer solar cells are herein presented utilizing the PBDTTT-CT donor and the P(NDI2OD-T2) acceptor with 1,8-diiodooctane (DIO) and 1-chloronaphthalene (CN) binary solvent additives. A systematic study of the polymer/polymer bulk heterojunction photovoltaic cells processed from the binary additives revealed that the microstructures and photophysics were quite different from those of a pristine system. The combination of DIO and CN with a DIO/CN ratio of 3:1 (3 vol% DIO, 1 vol% CN and 96 vol% o-DCB) led to suitable penetrating polymer networks, efficient charge generation and balanced charge transport, which were all beneficial to improving the efficiency. This improvement is attributed to increase in power conversion efficiency from 2.81% for a device without additives to 4.39% for a device with the binary processing additives. A detailed investigation indicates that the changes in the polymer:polymer interactions resulted in the formation of a percolating nasnoscale morphology upon processing with the binary additives. Depth profile measurements with a two-dimensional grazing incidence wide-angle X-ray scattering confirm this optimum phase feature. Furthermore impedance spectroscopy also finds evidence for synergistically boosting the device performance. PMID:26658472

  9. A Mechanistic Understanding of a Binary Additive System to Synergistically Boost Efficiency in All-Polymer Solar Cells

    NASA Astrophysics Data System (ADS)

    Kim, Yu Jin; Ahn, Sunyong; Wang, Dong Hwan; Park, Chan Eon

    2015-12-01

    All-polymer solar cells are herein presented utilizing the PBDTTT-CT donor and the P(NDI2OD-T2) acceptor with 1,8-diiodooctane (DIO) and 1-chloronaphthalene (CN) binary solvent additives. A systematic study of the polymer/polymer bulk heterojunction photovoltaic cells processed from the binary additives revealed that the microstructures and photophysics were quite different from those of a pristine system. The combination of DIO and CN with a DIO/CN ratio of 3:1 (3 vol% DIO, 1 vol% CN and 96 vol% o-DCB) led to suitable penetrating polymer networks, efficient charge generation and balanced charge transport, which were all beneficial to improving the efficiency. This improvement is attributed to increase in power conversion efficiency from 2.81% for a device without additives to 4.39% for a device with the binary processing additives. A detailed investigation indicates that the changes in the polymer:polymer interactions resulted in the formation of a percolating nasnoscale morphology upon processing with the binary additives. Depth profile measurements with a two-dimensional grazing incidence wide-angle X-ray scattering confirm this optimum phase feature. Furthermore impedance spectroscopy also finds evidence for synergistically boosting the device performance.

  10. A Mechanistic Understanding of a Binary Additive System to Synergistically Boost Efficiency in All-Polymer Solar Cells.

    PubMed

    Kim, Yu Jin; Ahn, Sunyong; Wang, Dong Hwan; Park, Chan Eon

    2015-12-11

    All-polymer solar cells are herein presented utilizing the PBDTTT-CT donor and the P(NDI2OD-T2) acceptor with 1,8-diiodooctane (DIO) and 1-chloronaphthalene (CN) binary solvent additives. A systematic study of the polymer/polymer bulk heterojunction photovoltaic cells processed from the binary additives revealed that the microstructures and photophysics were quite different from those of a pristine system. The combination of DIO and CN with a DIO/CN ratio of 3:1 (3 vol% DIO, 1 vol% CN and 96 vol% o-DCB) led to suitable penetrating polymer networks, efficient charge generation and balanced charge transport, which were all beneficial to improving the efficiency. This improvement is attributed to increase in power conversion efficiency from 2.81% for a device without additives to 4.39% for a device with the binary processing additives. A detailed investigation indicates that the changes in the polymer:polymer interactions resulted in the formation of a percolating nasnoscale morphology upon processing with the binary additives. Depth profile measurements with a two-dimensional grazing incidence wide-angle X-ray scattering confirm this optimum phase feature. Furthermore impedance spectroscopy also finds evidence for synergistically boosting the device performance.

  11. Suitable parameter choice on quantitative morphology of A549 cell in epithelial–mesenchymal transition

    PubMed Central

    Ren, Zhou-Xin; Yu, Hai-Bin; Li, Jian-Sheng; Shen, Jun-Ling; Du, Wen-Sen

    2015-01-01

    Evaluation of morphological changes in cells is an integral part of study on epithelial to mesenchymal transition (EMT), however, only a few papers reported the changes in quantitative parameters and no article compared different parameters for demanding better parameters. In the study, the purpose was to investigate suitable parameters for quantitative evaluation of EMT morphological changes. A549 human lung adenocarcinoma cell line was selected for the study. Some cells were stimulated by transforming growth factor-β1 (TGF-β1) for EMT, and other cells were as control without TGF-β1 stimulation. Subsequently, cells were placed in phase contrast microscope and three arbitrary fields were captured and saved with a personal computer. Using the tools of Photoshop software, some cells in an image were selected, segmented out and exchanged into unique hue, and other part in the image was shifted into another unique hue. The cells were calculated with 29 morphological parameters by Image Pro Plus software. A parameter between cells with or without TGF-β1 stimulation was compared statistically and nine parameters were significantly different between them. Receiver operating characteristic curve (ROC curve) of a parameter was described with SPSS software and F-test was used to compare two areas under the curves (AUCs) in Excel. Among them, roundness and radius ratio were the most AUCs and were significant higher than the other parameters. The results provided a new method with quantitative assessment of cell morphology during EMT, and found out two parameters, roundness and radius ratio, as suitable for quantification. PMID:26182364

  12. Effects of Angular Frequency During Clinorotation on Mesenchymal Stem Cell Morphology and Migration

    NASA Technical Reports Server (NTRS)

    Luna, Carlos; Yew, Alvin G.; Hsieh, Adam H.

    2015-01-01

    Background/Objectives: Ground-based microgravity simulation can reproduce the apparent effects of weightlessness in spaceflight using clinostats that continuously reorient the gravity vector on a specimen, creating a time-averaged nullification of gravity. In this work, we investigated the effects of clinorotation speed on the morphology, cytoarchitecture, and migration behavior of human mesenchymal stem cells (hMSCs). Methods: We compared cell responses at clinorotation speeds of 0, 30, 60, and 75 rpm over 8 hours in a recently developed lab-on-chip-based clinostat system. Time lapse light microscopy was used to visualize changes in cell morphology during and after cessation of clinorotation. Cytoarchitecture was assessed by actin and vinculin staining, and chemotaxis was examined using time lapse light microscopy of cells in NGF (100 ng/ml) gradients. Results: Among clinorotated groups, cell area distributions indicated a greater inhibition of cell spreading with higher angular frequency (p is less than 0.005), though average cell area at 30 rpm after 8 hours became statistically similar to control (p = 0.794). Cells at 75rpm clinorotation remained viable and were able to re-spread after clinorotation. In chemotaxis chambers clinorotation did not alter migration patterns in elongated cells, but most clinorotated cells exhibited cell retraction, which strongly compromised motility.

  13. Morphology, properties, and performance of electrodeposited n-CdSe in liquid junction solar cells

    SciTech Connect

    Tomkiewicz, M.; Ling, I.; Parsons, W.S.

    1982-09-01

    The authors describe the mechanisms for galvanostatic electrodeposition of CdSe in terms of competition between chemical reactions that lead to Se formation and electrochemical reduction of Se as polyselenide, at the interfaces between selenium and selenide. This mechanism leads to a cauliflower morphology for the resulting film. This morphology is ideal for a photoanode in the liquid junction solar cell configuration, and the authors describe the performance of such an electrode. In spite of the unique morphology, solid-state properties of the film can be evaluated and the methodology for these evaluations is presented. The performance of the liquid junction solar cells is limited by the dark current and the dielectric properties of the material. The authors also describe the effects of metal ions such as Zn/sup +2/, Ru/sup +3/, and Ga/sup +3/ on the various electrode properties.

  14. Variable cell morphology approach for individual-based modeling of microbial communities.

    PubMed

    Storck, Tomas; Picioreanu, Cristian; Virdis, Bernardino; Batstone, Damien J

    2014-05-06

    An individual-based, mass-spring modeling framework has been developed to investigate the effect of cell properties on the structure of biofilms and microbial aggregates through Lagrangian modeling. Key features that distinguish this model are variable cell morphology described by a collection of particles connected by springs and a mechanical representation of deformable intracellular, intercellular, and cell-substratum links. A first case study describes the colony formation of a rod-shaped species on a planar substratum. This case shows the importance of mechanical interactions in a community of growing and dividing rod-shaped cells (i.e., bacilli). Cell-substratum links promote formation of mounds as opposed to single-layer biofilms, whereas filial links affect the roundness of the biofilm. A second case study describes the formation of flocs and development of external filaments in a mixed-culture activated sludge community. It is shown by modeling that distinct cell-cell links, microbial morphology, and growth kinetics can lead to excessive filamentous proliferation and interfloc bridging, possible causes for detrimental sludge bulking. This methodology has been extended to more advanced microbial morphologies such as filament branching and proves to be a very powerful tool in determining how fundamental controlling mechanisms determine diverse microbial colony architectures.

  15. Variable Cell Morphology Approach for Individual-Based Modeling of Microbial Communities

    PubMed Central

    Storck, Tomas; Picioreanu, Cristian; Virdis, Bernardino; Batstone, Damien J.

    2014-01-01

    An individual-based, mass-spring modeling framework has been developed to investigate the effect of cell properties on the structure of biofilms and microbial aggregates through Lagrangian modeling. Key features that distinguish this model are variable cell morphology described by a collection of particles connected by springs and a mechanical representation of deformable intracellular, intercellular, and cell-substratum links. A first case study describes the colony formation of a rod-shaped species on a planar substratum. This case shows the importance of mechanical interactions in a community of growing and dividing rod-shaped cells (i.e., bacilli). Cell-substratum links promote formation of mounds as opposed to single-layer biofilms, whereas filial links affect the roundness of the biofilm. A second case study describes the formation of flocs and development of external filaments in a mixed-culture activated sludge community. It is shown by modeling that distinct cell-cell links, microbial morphology, and growth kinetics can lead to excessive filamentous proliferation and interfloc bridging, possible causes for detrimental sludge bulking. This methodology has been extended to more advanced microbial morphologies such as filament branching and proves to be a very powerful tool in determining how fundamental controlling mechanisms determine diverse microbial colony architectures. PMID:24806936

  16. Influence of curvature on the morphology of brain microvascular endothelial cells

    NASA Astrophysics Data System (ADS)

    Ye, Mao; Yang, Zhen; Wong, Andrew; Searson, Peter; Searson Group Team

    2013-03-01

    There are hundreds or thousands of endothelial cells around the perimeter of a single artery or vein, and hence an individual cell experiences little curvature. In contrast, a single endothelial cell may wrap around itself to form the lumen of a brain capillary. Curvature plays a key role in many biological, chemical and physical processes, however, its role in dictating the morphology and polarization of brain capillary endothelial cells has not been investigated. We hypothesize that curvature and shear flow play a key role in determining the structure and function of the blood-brain barrier (BBB). We have developed the ``rod'' assay to study the influence of curvature on the morphology of confluent monolayers of endothelial cells. In this assay cells are plated onto glass rods pulled down to the desired diameter in the range from 5 - 500 μm and coated with collagen. We show that curvature has a significant influence on the morphology of endothelial cells and may have an important role in blood-brain barrier function.

  17. Intratumoral morphologic and molecular heterogeneity of rhabdoid renal cell carcinoma: challenges for personalized therapy.

    PubMed

    Singh, Rajesh R; Murugan, Paari; Patel, Lalit R; Voicu, Horatiu; Yoo, Suk-Young; Majewski, Tadeusz; Mehrotra, Meenakshi; Wani, Khalida; Tannir, Nizar; Karam, Jose A; Jonasch, Eric; Wood, Christopher G; Creighton, Chad J; Medeiros, L Jeffrey; Broaddus, Russell R; Tamboli, Pheroze; Baggerly, Keith A; Aldape, Kenneth D; Czerniak, Bogdan; Luthra, Rajyalakshmi; Sircar, Kanishka

    2015-09-01

    Rhabdoid histology in clear-cell renal cell carcinoma is associated with a poor prognosis. The prognosis of patients with clear-cell renal cell carcinoma may also be influenced by molecular alterations. The aim of this study was to evaluate the association between histologic features and salient molecular changes in rhabdoid clear-cell renal cell carcinoma. We macrodissected the rhabdoid and clear-cell epithelioid components from 12 cases of rhabdoid clear-cell renal cell carcinoma. We assessed cancer-related mutations from eight cases using a clinical next-generation exome-sequencing platform. The transcriptome of rhabdoid clear-cell renal cell carcinoma (n=8) and non-rhabdoid clear-cell renal cell carcinoma (n=37) was assessed by RNA-seq and gene expression microarray. VHL (63%) showed identical mutations in all regions from the same tumor. BAP1 (38%) and PBRM1 (13%) mutations were identified in the rhabdoid but not in the epithelioid component and were mutually exclusive in 3/3 cases and 1 case, respectively. SETD2 (63%) mutations were discordant between different histologic regions in 2/5 cases, with mutations called only in the epithelioid and rhabdoid components, respectively. The transcriptome of rhabdoid clear-cell renal cell carcinoma was distinct from advanced-stage and high-grade clear-cell renal cell carcinoma. The diverse histologic components of rhabdoid clear-cell renal cell carcinoma, however, showed a similar transcriptomic program, including a similar prognostic gene expression signature. Rhabdoid clear-cell renal cell carcinoma is transcriptomically distinct and shows a high rate of SETD2 and BAP1 mutations and a low rate of PBRM1 mutations. Driver mutations in clear-cell renal cell carcinoma are often discordant across different morphologic regions, whereas the gene expression program is relatively stable. Molecular profiling of clear-cell renal cell carcinoma may improve by assessing for gene expression and sampling tumor foci from different

  18. Intratumoral Morphologic and Molecular Heterogeneity of Rhabdoid Renal Cell Carcinoma: Challenges for Personalized Therapy

    PubMed Central

    Singh, Rajesh R.; Murugan, Paari; Patel, Lalit R.; Voicu, Horatiu; Yoo, Suk-Young; Majewski, Tadeusz; Mehrotra, Meenakshi; Wani, Khalida; Tannir, Nizar; Karam, Jose A.; Jonasch, Eric; Wood, Christopher G.; Creighton, Chad J.; Medeiros, L. Jeffrey; Broaddus, Russell R.; Tamboli, Pheroze; Baggerly, Keith A.; Aldape, Kenneth D.; Czerniak, Bogdan; Luthra, Rajyalakshmi; Sircar, Kanishka

    2015-01-01

    Rhabdoid histology in clear cell renal cell carcinoma is associated with a poor prognosis. The prognosis of patients with clear cell renal cell carcinoma may also be influenced by molecular alterations. The aim of this study was to evaluate the association between histologic features and salient molecular changes in rhabdoid clear cell renal cell carcinoma. We macrodissected the rhabdoid and clear cell epithelioid components from 12 cases of rhabdoid clear cell renal cell carcinoma. We assessed cancer related mutations from 8 cases using a clinical next generation exome sequencing platform. The transcriptome of rhabdoid clear cell renal cell carcinoma (n=8) and non-rhabdoid clear cell renal cell carcinoma (n=37) was assessed by RNA-seq and gene expression microarray. VHL (63%) showed identical mutations in all regions from the same tumor. BAP1 (38%) and PBRM1 (13%) mutations were identified in the rhabdoid but not the epithelioid component and were mutually exclusive in 3/3 cases and 1 case, respectively. SETD2 (63%) mutations were discordant between different histologic regions in 2/5 cases, with mutations called only in the epithelioid and rhabdoid components, respectively. The transcriptome of rhabdoid clear cell renal cell carcinoma was distinct from advanced stage and high grade clear cell renal cell carcinoma. The diverse histologic components of rhabdoid clear cell renal cell carcinoma, however, showed a similar transcriptomic program, including a similar prognostic gene expression signature. Rhabdoid clear cell renal cell carcinoma is transcriptomically distinct and shows a high rate of SETD2 and BAP1 mutations and a low rate of PBRM1 mutations. Driver mutations in clear cell renal cell carcinoma are often discordant across different morphologic regions whereas the gene expression program is relatively stable. Molecular profiling of clear cell renal cell carcinoma may improve by assessing for gene expression and sampling tumor foci from different histologic

  19. ALS/FTLD-linked TDP-43 regulates neurite morphology and cell survival in differentiated neurons

    SciTech Connect

    Han, Jeong-Ho; Yu, Tae-Hoon; Ryu, Hyun-Hee; Jun, Mi-Hee; Ban, Byung-Kwan; Jang, Deok-Jin; Lee, Jin-A

    2013-08-01

    Tar-DNA binding protein of 43 kDa (TDP-43) has been characterized as a major component of protein aggregates in brains with neurodegenerative diseases such as frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). However, physiological roles of TDP-43 and early cellular pathogenic effects caused by disease associated mutations in differentiated neurons are still largely unknown. Here, we investigated the physiological roles of TDP-43 and the effects of missense mutations associated with diseases in differentiated cortical neurons. The reduction of TDP-43 by siRNA increased abnormal neurites and decreased cell viability. ALS/FTLD-associated missense mutant proteins (A315T, Q331K, and M337V) were partially mislocalized to the cytosol and neurites when compared to wild-type and showed abnormal neurites similar to those observed in cases of loss of TDP-43. Interestingly, cytosolic expression of wild-type TDP-43 with mutated nuclear localization signals also induced abnormal neurtie morphology and reduction of cell viability. However, there was no significant difference in the effects of cytosolic expression in neuronal morphology and cell toxicity between wild-type and missense mutant proteins. Thus, our results suggest that mislocalization of missense mutant TDP-43 may contribute to loss of TDP-43 function and affect neuronal morphology, probably via dominant negative action before severe neurodegeneration in differentiated cortical neurons. Highlights: • The function of nuclear TDP-43 in neurite morphology in mature neurons. • Partial mislocalization of TDP-43 missense mutants into cytosol from nucleus. • Abnormal neurite morphology caused by missense mutants of TDP-43. • The effect of cytosolic expression of TDP-43 in neurite morphology and in cell survival.

  20. Corticosterone induced morphological changes of hippocampal and amygdaloid cell lines are dependent on 5-HT7 receptor related signal pathway.

    PubMed

    Xu, Y; Zhang, C; Wang, R; Govindarajan, S S; Barish, P A; Vernon, M M; Fu, C; Acharya, A P; Chen, L; Boykin, E; Yu, J; Pan, J; O'Donnell, J M; Ogle, W O

    2011-05-19

    Stress is an unavoidable life experience. It induces mood, cognitive dysfunction and plasticity changes in chronically stressed individuals. Among the various brain regions that have been studied, the hippocampus and amygdala have been observed to have different roles in controlling the limbic-hypothalamic-pituitary-adrenal axis (limbic-HPA axis). This study investigated how the stress hormone corticosterone (CORT) affects neuronal cells. The first aim is to test whether administration of CORT to hippocampal and amygdaloid cell lines induces different changes in the 5-HT receptor subtypes. The second goal is to determine whether stress induced morphological changes in these two cell lines were involved in the 5-HT receptor subtypes expression. We now show that 5-HT(7) receptor mRNA levels were significantly upregulated in HT-22 cells, but downregulated in AR-5 cells by exposure to a physiologically relevant level of CORT (50 μM) for 24 h, which was later confirmed by primary hippocampal and amygdaloid neuron cultures. Additionally, pretreatment of cells with 5-HT(7) antagonist SB-269970 or agonist LP-44 reversed CORT induced cell lesion in a dose-dependent manner. Moreover, CORT induced different changes in neurite length, number of neurites and soma size in HT-22 and AR-5 cells were also reversed by pretreatment with either SB-269970 or LP-44. The different effects of 5-HT(7) receptors on cell lines were observed in two members of the Rho family small GTPase expression: the Cdc-42 and RhoA. These observed results support the hypothesis that 5-HT may differentially modulate neuronal morphology in the hippocampus and amygdala depending on the expression levels of the 5-HT receptor subtypes during stress hormone insults.

  1. Cortisol affects tight junction morphology between pavement cells of rainbow trout gills in single-seeded insert culture.

    PubMed

    Sandbichler, Adolf Michael; Farkas, Julia; Salvenmoser, Willi; Pelster, Bernd

    2011-12-01

    A primary culture system of rainbow trout gill pavement cells grown on permeable support (single-seeded insert, SSI) was used to examine histological and physiological changes induced by the addition of the corticosteroid hormone cortisol. Pavement cell epithelia were cultured under symmetrical conditions (L15 apical/L15 basolateral) and developed a high transepithelial resistance (TER, 6.84 ± 1.99 kΩ cm(2), mean ± SEM) with a low phenol red diffusion rate (PRD, 0.15 ± 0.03 μmol l(-1)/day). Addition of cortisol to the basolateral compartment increased TER twofold and reduced PRD threefold over a 5-day period. A similar increase in TER could be seen after 24 h apical freshwater (FW) in control cultures. In cortisol-treated cultures FW exposure did not change TER, but PRD increased significantly. Histochemical staining of the cytoskeleton of cells in SSI culture revealed a morphological partitioning into a single mucosal layer of polarized, polygonal cells featuring cortical F-actin rings which were comparable to F-actin rings of epithelial cells on the lamellar and filamental surface, and several unorganized serosal layers of cells with F-actin stress fibers. Addition of cortisol increased cell density by 18% and in the mucosal layer it led to smaller, less polygonal cells with increased height and increased cell contact area. In transmission electron microscopic images two pairs of cytoplasmatic electron-dense structures confining the zonula occludens apically and basally toward the zonula adhaerens were found. Addition of cortisol increased the distance between those paired structures, hence led to deeper tight junctions. The cortisol-induced increase in barrier properties, therefore, involves a structural fortification of the tight junctions which was not generally modified by a short 24-h apical freshwater stress. These results identify cortisol as a regulator of tight junction morphology between pavement cells of euryhaline fish such as the

  2. Breaking the barriers of all-polymer solar cells: Solving electron transporter and morphology problems

    NASA Astrophysics Data System (ADS)

    Gavvalapalli, Nagarjuna

    All-polymer solar cells (APSC) are a class of organic solar cells in which hole and electron transporting phases are made of conjugated polymers. Unlike polymer/fullerene solar cell, photoactive material of APSC can be designed to have hole and electron transporting polymers with complementary absorption range and proper frontier energy level offset. However, the highest reported PCE of APSC is 5 times less than that of polymer/fullerene solar cell. The low PCE of APSC is mainly due to: i) low charge separation efficiency; and ii) lack of optimal morphology to facilitate charge transfer and transport; and iii) lack of control over the exciton and charge transport in each phase. My research work is focused towards addressing these issues. The charge separation efficiency of APSC can be enhanced by designing novel electron transporting polymers with: i) broad absorption range; ii) high electron mobility; and iii) high dielectric constant. In addition to with the above parameters chemical and electronic structure of the repeating unit of conjugated polymer also plays a role in charge separation efficiency. So far only three classes of electron transporting polymers, CN substituted PPV, 2,1,3-benzothiadiazole derived polymers and rylene diimide derived polymers, are used in APSC. Thus to enhance the charge separation efficiency new classes of electron transporting polymers with the above characteristics need to be synthesized. I have developed a new straightforward synthetic strategy to rapidly generate new classes of electron transporting polymers with different chemical and electronic structure, broad absorption range, and high electron mobility from readily available electron deficient monomers. In APSCs due to low entropy of mixing, polymers tend to micro-phase segregate rather than forming the more useful nano-phase segregation. Optimizing the polymer blend morphology to obtain nano-phase segregation is specific to the system under study, time consuming, and not

  3. Morphologic and proteomic characterization of exosomes released by cultured extravillous trophoblast cells

    SciTech Connect

    Atay, Safinur; Gercel-Taylor, Cicek; Kesimer, Mehmet; Taylor, Douglas D.

    2011-05-01

    Exosomes represent an important intercellular communication vehicle, mediating events essential for the decidual microenvironment. While we have demonstrated exosome induction of pro-inflammatory cytokines, to date, no extensive characterization of trophoblast-derived exosomes has been provided. Our objective was to provide a morphologic and proteomic characterization of these exosomes. Exosomes were isolated from the conditioned media of Swan71 human trophoblast cells by ultrafiltration and ultracentrifugation. These were analyzed for density (sucrose density gradient centrifugation), morphology (electron microscopy), size (dynamic light scattering) and protein composition (Ion Trap mass spectrometry and western immunoblotting). Based on density gradient centrifugation, microvesicles from Sw71 cells exhibit a density between 1.134 and 1.173 g/ml. Electron microscopy demonstrated that microvesicles from Sw71 cells exhibit the characteristic cup-shaped morphology of exosomes. Dynamic light scattering showed a bell-shaped curve, indicating a homogeneous population with a mean size of 165 nm {+-} 0.5 nm. Ion Trap mass spectrometry demonstrated the presence of exosome marker proteins (including CD81, Alix, cytoskeleton related proteins, and Rab family). The MS results were confirmed by western immunoblotting. Based on morphology, density, size and protein composition, we defined the release of exosomes from extravillous trophoblast cells and provide their first extensive characterization. This characterization is essential in furthering our understanding of 'normal' early pregnancy.

  4. Nanofiber Composite Membranes for Alkaline Fuel Cells: Generation of Compositional, Morphological, and Functional Property Relationships

    DTIC Science & Technology

    2015-12-01

    properties of nanofiber composite anion-exchange membranes for alkaline fuel cells. A new membrane fabrication strategy, utilizing polymer fiber...electrospinning, will be employed to make hydroxide-conducting membranes with an entirely new morphology, where one electrospun polymer provides pathways...for ion conductivity and the second electrospun polymer restricts ionomer swelling and imparts mechanical strength to the membrane. The functional

  5. [Cultivation and morphological characteristics of rat adipose tissue-derived vascular endothelial cells in vitro].

    PubMed

    Lin, Yunfeng; Chen, Xizhe; Tian, Weidong; Yan, Zhengbin; Zheng, Xiaohui

    2006-08-01

    The subcutaneous adipose tissue from the inguen of four Sprague-Dawley rats was obtained, then digested with one volume of collagenase type I and cultured with BGJb medium. The obtained adipose stromal cells were induced in human endothelial-SFM for 7 d. The cells were observed under inverted microscope every day and identified by transmission electron microscope and immunocytochemical staining with factor VIII antigen. The results showed the induced cells uniformly had characteristic cobblestone morphology of endothelial cells. Factor VIII antigen staining was positive in cytoplasm. Under transmission electron microscope, the cells displayed many finger like microvilli and numerous lysosomes, mitochondria, a few coarse endoplasmic reticulum and Weibel-Palade bodies. The characteristics of the rat adipose tissue-derived endothelial cells were consistent with those of vascular endothelial cells derived from other tissues. It seems that subcutaneous adipose tissue may represent a new alternative source of endogenous vascular endothelial cells.

  6. Using volatile additives to alter the morphology and performance of active layers in thin-film molecular photovoltaic devices incorporating bulk heterojunctions.

    PubMed

    Dang, Minh Trung; Wuest, James D

    2013-12-07

    Thin-film photovoltaic devices composed of polymers or small molecules have an exciting future as sources of renewable energy because they can be made in large sizes on flexible surfaces by inexpensive techniques of fabrication. Significant progress in developing new molecular photovoltaic materials and device architectures has been achieved in the last decade. The identity of molecular components in active layers and their individual optoelectronic properties obviously help determine the properties of devices; in addition, however, the behavior of devices depends critically on the nature of the local organization of the components. Recent studies have shown that the morphology of active layers can be tuned by adjusting various parameters, including the solvent used to cast the layer, thermal annealing, and special processing additives. In this review, we summarize the effect of volatile additives on the nanoscale morphology of molecular blends, and we show how these effects can improve the performance of devices. Although we focus on the behavior of mixtures of the type used in current molecular thin-film photovoltaic devices, the subject of our review will interest researchers in all areas of science and technology requiring materials in which separate phases must form intimate long-lived intermixtures with defined structures.

  7. Human aortic endothelial cell morphology influenced by topography of porous silicon substrates.

    PubMed

    Formentín, Pilar; Catalán, Úrsula; Fernández-Castillejo, Sara; Alba, Maria; Baranowska, Malgorzata; Solà, Rosa; Pallarès, Josep; Marsal, Lluís F

    2015-10-01

    Porous silicon has received much attention because of its optical properties and for its usefulness in cell-based biosensing, drug delivery, and tissue engineering applications. Surface properties of the biomaterial are associated with cell adhesion and with proliferation, migration, and differentiation. The present article analyzes the behavior of human aortic endothelial cells in macro- and nanoporous collagen-modified porous silicon samples. On both substrates, cells are well adhered and numerous. Confocal microscopy and scanning electron microscopy were employed to study the effects of porosity on the morphology of the cells. On macroporous silicon, filopodia is not observed but the cell spreads on the surface, increasing the lamellipodia surface which penetrates the macropore. On nanoporous silicon, multiple filopodia were found to branch out from the cell body. These results demonstrate that the pore size plays a key role in controlling the morphology and growth rate of human aortic endothelial cells, and that these forms of silicon can be used to control cell development in tissue engineering as well as in basic cell biology research.

  8. Liver-cell patterning lab chip: mimicking the morphology of liver lobule tissue.

    PubMed

    Ho, Chen-Ta; Lin, Ruei-Zeng; Chen, Rong-Jhe; Chin, Chung-Kuang; Gong, Song-En; Chang, Hwan-You; Peng, Hwei-Ling; Hsu, Long; Yew, Tri-Rung; Chang, Shau-Feng; Liu, Cheng-Hsien

    2013-09-21

    A lobule-mimetic cell-patterning technique for on-chip reconstruction of centimetre-scale liver tissue of heterogeneous hepatic and endothelial cells via an enhanced field-induced dielectrophoresis (DEP) trap is demonstrated and reported. By mimicking the basic morphology of liver tissue, the classic hepatic lobule, the lobule-mimetic-stellate-electrodes array was designed for cell patterning. Through DEP manipulation, well-defined and enhanced spatial electric field gradients were created for in-parallel manipulation of massive individual cells. With this liver-cell patterning labchip design, the original randomly distributed hepatic and endothelial cells inside the microfluidic chamber can be manipulated separately and aligned into the desired pattern that mimicks the morphology of liver lobule tissue. Experimental results showed that both hepatic and endothelial cells were orderly guided, snared, and aligned along the field-induced orientation to form the lobule-mimetic pattern. About 95% cell viability of hepatic and endothelial cells was also observed after cell-patterning demonstration via a fluorescent assay technique. The liver function of CYP450-1A1 enzyme activity showed an 80% enhancement for our engineered liver tissue (HepG2+HUVECs) compared to the non-patterned pure HepG2 for two-day culturing.

  9. Observation of Nanoscale Morphological and Structural Degradation in Perovskite Solar Cells by In-Situ TEM

    DOE PAGES

    Yang, Bin; Dyck, Ondrej K.; Univ. of Tennessee, Knoxville, TN; ...

    2016-11-04

    The chemical stability of organometallic halide perovskites is a major barrier facing their application in the fast rising field of next generation photovoltaics. These materials were shown to undergo degradation due to the influence of heat or moisture, significantly limiting the lifetime of associated devices. To overcome this stability issue, a fundamental understanding of degradation mechanisms is of foremost importance. Here, high resolution in situ transmission electron microscopy and electron energy loss spectroscopy elemental mapping were applied to probe morphological and structural changes in perovskite films during controlled environmental exposure treatments. Both moisture and oxygen in ambient air are revealedmore » to facilitate degradation in CH3NH3PbI3 perovskites through decomposition and oxidation pathways, respectively. In addition, even in moisture- and oxygen-free environment evident degradation could be induced by heating at the solar cell s real-field operating temperature and the degradation was found to originate from defect sites. These findings provide fundamental insight to prevent degradation of perovskite materials and associated devices for realistic applications.« less

  10. Observation of Nanoscale Morphological and Structural Degradation in Perovskite Solar Cells by In-Situ TEM

    SciTech Connect

    Yang, Bin; Dyck, Ondrej K.; Ming, Wenmei; Du, Mao-Hua; Das, Sanjib; Rouleau, Christopher M.; Duscher, Gerd; Geohegan, David B.; Xiao, Kai

    2016-11-04

    The chemical stability of organometallic halide perovskites is a major barrier facing their application in the fast rising field of next generation photovoltaics. These materials were shown to undergo degradation due to the influence of heat or moisture, significantly limiting the lifetime of associated devices. To overcome this stability issue, a fundamental understanding of degradation mechanisms is of foremost importance. Here, high resolution in situ transmission electron microscopy and electron energy loss spectroscopy elemental mapping were applied to probe morphological and structural changes in perovskite films during controlled environmental exposure treatments. Both moisture and oxygen in ambient air are revealed to facilitate degradation in CH3NH3PbI3 perovskites through decomposition and oxidation pathways, respectively. In addition, even in moisture- and oxygen-free environment evident degradation could be induced by heating at the solar cell s real-field operating temperature and the degradation was found to originate from defect sites. These findings provide fundamental insight to prevent degradation of perovskite materials and associated devices for realistic applications.

  11. Mitotic position and morphology of committed precursor cells in the zebrafish retina adapt to architectural changes upon tissue maturation.

    PubMed

    Weber, Isabell P; Ramos, Ana P; Strzyz, Paulina J; Leung, Louis C; Young, Stephen; Norden, Caren

    2014-04-24

    The development of complex neuronal tissues like the vertebrate retina requires the tight orchestration of cell proliferation and differentiation. Although the complexity of transcription factors and signaling pathways involved in retinogenesis has been studied extensively, the influence of tissue maturation itself has not yet been systematically explored. Here, we present a quantitative analysis of mitotic events during zebrafish retinogenesis that reveals three types of committed neuronal precursors in addition to the previously known apical progenitors. The identified precursor types present at distinct developmental stages and exhibit different mitotic location (apical versus nonapical), cleavage plane orientation, and morphology. Interestingly, the emergence of nonapically dividing committed bipolar cell precursors can be linked to an increase in apical crowding caused by the developing photoreceptor cell layer. Furthermore, genetic interference with neuronal subset specification induces ectopic divisions of committed precursors, underlining the finding that progressing morphogenesis can effect precursor division position.

  12. Filopodial morphology correlates to the capture efficiency of primary T-cells on nanohole arrays.

    PubMed

    Kim, Dong-Joo; Kim, Gil-Sung; Seol, Jin-Kyeong; Hyung, Jung-Hwan; Park, No-Won; Lee, Mi-Ri; Lee, Myung Kyu; Fan, Rong; Lee, Sang-Kwon

    2014-06-01

    Nanostructured surfaces emerge as a new class of material for capture and separation of cell populations including primary immune cells and disseminating rare tumor cells, but the underlying mechanism remains elusive. Although it has been speculated that nanoscale topological structures on cell surface are involved in the cell capture process, there are no studies that systematically analyze the relation between cell surface structures and the capture efficiency. Here we report on the first mechanistic study by quantifying the morphological parameters of cell surface nanoprotrusions, including filopodia, lamellipodia, and microvilli in the early stage of cell capture (< 20 min) in correlation to the efficiency of separating primary T lymphocytes. This was conducted by using a set of nanohole arrays (NHAs) with varying hole and pitch sizes. Our results showed that the formation of filopodia (e.g., width of filopodia and the average number of the filopodial filaments per cell) depends on the feature size of the nanostructures and the cell separation efficiency is strongly correlated to the number of filopodial fibers, suggesting a possible role of early stage mechanosensing and cell spreading in determining the efficiency of cell capture. In contrast, the length of filopodial filaments was less significantly correlated to the cell capture efficiency and the nanostructure dimensions of the NHAs. This is the first mechanistic study on nanostructure-based immune cell capture and provides new insights to not only the biology of cell-nanomaterial interaction but also the design of new rare cell capture technologies with improved efficiency and specificity.

  13. Periodic Mesoporous Organosilica Nanoparticles with Controlled Morphologies and High Drug/Dye Loadings for Multicargo Delivery in Cancer Cells.

    PubMed

    Croissant, Jonas G; Fatieiev, Yevhen; Omar, Haneen; Anjum, Dalaver H; Gurinov, Andrey; Lu, Jie; Tamanoi, Fuyuhiko; Zink, Jeffrey I; Khashab, Niveen M

    2016-07-04

    Despite the worldwide interest generated by periodic mesoporous organosilica (PMO) bulk materials, the design of PMO nanomaterials with controlled morphology remains largely unexplored and their properties unknown. In this work, we describe the first study of PMO nanoparticles (NPs) based on meta-phenylene bridges, and we conducted a comparative structure-property relationship investigation with para-phenylene-bridged PMO NPs. Our findings indicate that the change of the isomer drastically affects the structure, morphology, size, porosity and thermal stability of PMO materials. We observed a much higher porosity and thermal stability of the para-based PMO which was likely due to a higher molecular periodicity. Additionally, the para isomer could generate multipodal NPs at very low stirring speed and upon this discovery we designed a phenylene-ethylene bridged PMO with a controlled Janus morphology. Unprecedentedly high payloads could be obtained from 40 to 110 wt % regardless of the organic bridge of PMOs. Finally, we demonstrate for the first time the co-delivery of two cargos by PMO NPs. Importantly, the cargo stability in PMOs did not require the capping of the pores, unlike pure silica, and the delivery could be autonomously triggered in cancer cells by acidic pH with nearly 70 % cell killing.

  14. Bi-Sn alloy catalyst for simultaneous morphology and doping control of silicon nanowires in radial junction solar cells

    SciTech Connect

    Yu, Zhongwei; Lu, Jiawen; Qian, Shengyi; Xu, Jun; Xu, Ling; Wang, Junzhuan; Shi, Yi; Chen, Kunji; Yu, Linwei E-mail: linwei.yu@polytechnique.edu

    2015-10-19

    Low-melting point metals such as bismuth (Bi) and tin (Sn) are ideal choices for mediating a low temperature growth of silicon nanowires (SiNWs) for radial junction thin film solar cells. The incorporation of Bi catalyst atoms leads to sufficient n-type doping in the SiNWs core that exempts the use of hazardous dopant gases, while an easy morphology control with pure Bi catalyst has never been demonstrated so far. We here propose a Bi-Sn alloy catalyst strategy to achieve both a beneficial catalyst-doping and an ideal SiNW morphology control. In addition to a potential of further growth temperature reduction, we show that the alloy catalyst can remain quite stable during a vapor-liquid-solid growth, while providing still sufficient n-type catalyst-doping to the SiNWs. Radial junction solar cells constructed over the alloy-catalyzed SiNWs have demonstrated a strongly enhanced photocurrent generation, thanks to optimized nanowire morphology, and largely improved performance compared to the reference samples based on the pure Bi or Sn-catalyzed SiNWs.

  15. Temperature and CO(2) additively regulate physiology, morphology and genomic responses of larval sea urchins, Strongylocentrotus purpuratus.

    PubMed

    Padilla-Gamiño, Jacqueline L; Kelly, Morgan W; Evans, Tyler G; Hofmann, Gretchen E

    2013-05-22

    Ocean warming and ocean acidification, both consequences of anthropogenic production of CO2, will combine to influence the physiological performance of many species in the marine environment. In this study, we used an integrative approach to forecast the impact of future ocean conditions on larval purple sea urchins (Strongylocentrotus purpuratus) from the northeast Pacific Ocean. In laboratory experiments that simulated ocean warming and ocean acidification, we examined larval development, skeletal growth, metabolism and patterns of gene expression using an orthogonal comparison of two temperature (13°C and 18°C) and pCO2 (400 and 1100 μatm) conditions. Simultaneous exposure to increased temperature and pCO2 significantly reduced larval metabolism and triggered a widespread downregulation of histone encoding genes. pCO2 but not temperature impaired skeletal growth and reduced the expression of a major spicule matrix protein, suggesting that skeletal growth will not be further inhibited by ocean warming. Importantly, shifts in skeletal growth were not associated with developmental delay. Collectively, our results indicate that global change variables will have additive effects that exceed thresholds for optimized physiological performance in this keystone marine species.

  16. Understanding Solvent Manipulation of Morphology in Bulk-Heterojunction Organic Solar Cells.

    PubMed

    Chen, Yuxia; Zhan, Chuanlang; Yao, Jiannian

    2016-10-06

    Film morphology greatly influences the performance of bulk-heterojunction (BHJ)-structure-based solar cells. It is known that an interpenetrating bicontinuous network with nanoscale-separated donor and acceptor phases for charge transfer, an ordered molecular packing for exciton diffusion and charge transport, and a vertical compositionally graded structure for charge collection are prerequisites for achieving highly efficient BHJ organic solar cells (OSCs). Therefore, control of the morphology to obtain an ideal structure is a key problem. For this solution-processing BHJ system, the solvent participates fully in film processing. Its involvement is critical in modifying the nanostructure of BHJ films. In this review, we discuss the effects of solvent-related methods on the morphology of BHJ films, including selection of the casting solvent, solvent mixture, solvent vapor annealing, and solvent soaking. On the basis of a discussion on interaction strength and time between solvent and active materials, we believe that the solvent-morphology-performance relationship will be clearer and that solvent selection as a means to manipulate the morphology of BHJ films will be more rational.

  17. Hybrid morphology dependence of CdTe:CdSe bulk-heterojunction solar cells.

    PubMed

    Tan, Furui; Qu, Shengchun; Zhang, Weifeng; Wang, Zhanguo

    2014-01-01

    A nanocrystal thin-film solar cell operating on an exciton splitting pattern requires a highly efficient separation of electron-hole pairs and transportation of separated charges. A hybrid bulk-heterojunction (HBH) nanostructure providing a large contact area and interpenetrated charge channels is favorable to an inorganic nanocrystal solar cell with high performance. For this freshly appeared structure, here in this work, we have firstly explored the influence of hybrid morphology on the photovoltaic performance of CdTe:CdSe bulk-heterojunction solar cells with variation in CdSe nanoparticle morphology. Quantum dot (QD) or nanotetrapod (NT)-shaped CdSe nanocrystals have been employed together with CdTe NTs to construct different hybrid structures. The solar cells with the two different hybrid active layers show obvious difference in photovoltaic performance. The hybrid structure with densely packed and continuously interpenetrated two phases generates superior morphological and electrical properties for more efficient inorganic bulk-heterojunction solar cells, which could be readily realized in the NTs:QDs hybrid. This proved strategy is applicable and promising in designing other highly efficient inorganic hybrid solar cells.

  18. The relationship of fibroblast translocations to cell morphology and stress fibre density.

    PubMed

    Lewis, L; Verna, J M; Levinstone, D; Sher, S; Marek, L; Bell, E

    1982-02-01

    Translocation of human fibroblasts in culture was studied using techniques of time-lapse cinemicrography, indirect immunofluorescence, and computer analysis. An inverse relationship between the velocity of cells during the last hour of life and the density of stress fibers seen by immune staining was demonstrated. Translocating cells generally assumed one of two interconvertible morphologies: a triangular tailed shape or tailed fibroblast (TF), and a tailless form that resembled a half-moon, which we call a half-moon fibroblast (HMF). The tail of TFs formed only on regions of substrate that had been previously traversed by cells. The half-moon morphology developed either on previously used or on virgin substrate. Cells adopted the HMF rather than the TF morphology with a four-fold greater frequency. HMFs translocated slightly faster than TFs. The foregoing observation suggest that the fibroblast tail is not an organelle essential for translocation. Since our technique allowed us to distinguish between cells which were cycling and those which had left cycle, we compared their velocities and found them to be similar. Also the average velocities of cells of different population-doubling levels (10th, 30th, 40th) were approximately equal.

  19. Influence of boron addition to Ti-13Zr-13Nb alloy on MG63 osteoblast cell viability and protein adsorption.

    PubMed

    Majumdar, P; Singh, S B; Dhara, S; Chakraborty, M

    2015-01-01

    Cell proliferation, cell morphology and protein adsorption on near β-type Ti-13Zr-13Nb (TZN) alloy and Ti-13Zr-13Nb-0.5B (TZNB) composite have been investigated and compared to evaluate the effect of boron addition which has been added to the Ti alloy to improve their poor tribological properties by forming in situ TiB precipitates. MG63 cell proliferation on substrates with different chemistry but the same topography was compared. The MTT assay test showed that the cell viability on the TZN alloy was higher than the boron containing TZNB composite after 36 h of incubation and the difference was pronounced after 7 days. However, both the materials showed substantially higher cell attachment than the control (polystyrene). For the same period of incubation in fetal bovine serum (FBS), the amount of protein adsorbed on the surface of boron free TZN samples was higher than that in the case of boron containing TZNB composite. The presence of boron in the TZN alloy influenced protein adsorption and cell response and they are lower in TZNB than in TZN as a result of the associated difference in chemical characteristics.

  20. Morphological characterization of testicular cells, spermatogenesis and formation of spermatophores in a fish ectoparasite Argulus bengalensis Ramakrishna, 1951 (Crustacea: Branchiura).

    PubMed

    Banerjee, Anirban; Manna, Subha; Saha, Samar Kumar

    2014-02-01

    The present study has been carried out to describe the cell morphology of the developing male gametes in a fish ectoparasite, Argulus bengalensis Ramakrishna, 1951. With respect to cell volume and nucleoplasmic index, spermatogonia are the smallest and primary spermatocytes are the largest in this lineage. The spermatogonia and the differentiating spermatogenic cells are in separate niches and confined to different enclaves within each testicular lobe. Spermiogenesis occurs within the inner enclave of each testicular lobe. During this process the nucleus becomes streamlined; an acrosome is formed, axoneme is originated, and residual cytoplasm is discarded through the flagellum. The sperm cell morphology displays a general pattern comprising head, mid-piece, and a full length flagellum. In the axoneme 9+2 arrangement of the microtubule is conserved. In addition to the axoneme, some more singlet microtubules are found surrounding a fiber sheath and around one of the mitochondria adjacent to the axoneme. This arrangement indicates a close phylogenetic relationship with pentastomida. In the present study, structure and formation of spermatophore are described in this branchiuran parasite.

  1. The proton dissociation constant of additive effect on self-assembly of poly(3-hexyl-thiophene) for organic solar cells

    NASA Astrophysics Data System (ADS)

    Wang, Po-Hsun; Lee, Hsu-Feng; Huang, Yi-Chiang; Jung, Yi-Jiun; Gong, Fang-Lin; Huang, Wen-Yao

    2014-07-01

    In the decision on the pros and cons of the optical and electrical properties of organic solar cells, the morphology has proven to be very important. Easy to change the morphology via adding a small amount of additive, because proton dissociation constant is the main reason for their application. In this study, the use of poly(3-hexylthiophene) and [6,6]-phenyl C 61-butyric acid methyl ester as the donor and acceptor materials, and were subsequently doped with different quantity of 4,4'-sulfonyldiphenol, 4,4'-dihydroxybiphenyl, biphenyl-4,4'-dithiol. When the proton dissociation constant is higher and lower respectively, the morphology reveals earthworms-like and fiber-like. For the reason that when the additive is biphenyl-4,4'-dithiol, it can improve the power conversion efficiency of about 27% and the incident photon-to-current conversion efficiency of about 12%.

  2. Retinal ganglion cells in the eastern newt Notophthalmus viridescens: topography, morphology, and diversity.

    PubMed

    Pushchin, Igor I; Karetin, Yuriy A

    2009-10-20

    The topography and morphology of retinal ganglion cells (RGCs) in the eastern newt were studied. Cells were retrogradely labeled with tetramethylrhodamine-conjugated dextran amines or horseradish peroxidase and examined in retinal wholemounts. Their total number was 18,025 +/- 3,602 (mean +/- SEM). The spatial density of RGCs varied from 2,100 cells/mm(2) in the retinal periphery to 4,500 cells/mm(2) in the dorsotemporal retina. No prominent retinal specializations were found. The spatial resolution estimated from the spatial density of RGCs varied from 1.4 cycles per degree in the periphery to 1.95 cycles per degree in the region of the peak RGC density. A sample of 68 cells was camera lucida drawn and subjected to quantitative analysis. A total of 21 parameters related to RGC morphology and stratification in the retina were estimated. Partitionings obtained by using different clustering algorithms combined with automatic variable weighting and dimensionality reduction techniques were compared, and an effective solution was found by using silhouette analysis. A total of seven clusters were identified and associated with potential cell types. Kruskal-Wallis ANOVA-on-Ranks with post hoc Mann-Whitney U tests showed significant pairwise between-cluster differences in one or more of the clustering variables. The average silhouette values of the clusters were reasonably high, ranging from 0.52 to 0.79. Cells assigned to the same cluster displayed similar morphology and stratification in the retina. The advantages and limitations of the methodology adopted are discussed. The present classification is compared with known morphological and physiological RGC classifications in other salamanders.

  3. Kinetoplast morphology and segregation pattern as a marker for cell cycle progression in Leishmania donovani.

    PubMed

    Minocha, Neha; Kumar, Devanand; Rajanala, Kalpana; Saha, Swati

    2011-01-01

    Trypanosomatids are typified by uniquely configured mitochondrial DNA--the kinetoplast. The replication timing of kinetoplast DNA (kDNA) is closely linked to nuclear S phase, but nuclear and kinetoplast compartments display staggered timing of segregation, post-replication. Kinetoplast division is completed before nuclear division in Trypanosoma species while nuclear division is completed first in Crithidia species. Leishmania donovani is the causative agent of visceral leishmaniasis, a form of leishmanial infection that is often fatal. Cell cycle related studies in Leishmania are hampered by difficulties in synchronizing these cells. This report examines the replication/segregation pattern and morphology of the kinetoplast in L. donovani with the aim of determining if these traits can be used to assign cell cycle stage to individual cells. By labeling replicating cells with bromodeoxyuridine after synchronization with hydroxyurea, we find that although both nuclear and kDNA initiate replication in early S phase, nuclear division precedes kinetoplast segregation in 80% of the cells. The kinetoplast is roundish/short rod-like in G1 and in early to mid-S phase, but prominently elongated/bilobed in late S phase and early G2/M. These morphological traits and segregation pattern of the kinetoplast can be used as a marker for cell cycle stage in a population of asynchronously growing L. donovani promastigotes, in place of cell synchronization procedures or instead of using antibody staining for cell cycle stage marker proteins.

  4. Morphological analysis of nuclear separation and cell division during the life cycle of Escherichia coli.

    PubMed Central

    Woldringh, C L

    1976-01-01

    Quantitative electron microscope observations were performed on Escherichia coli B/r after balanced growth with doubling times (tau) of 32 and 60 min. The experimental approach allowed the timing of morphological events during the cell cycle by classifying serially sectioned cells according to length. Visible separation of the nucleoplasm was found to coincide with the time of termination of chromosome replication as predicted by the Cooper-Helmstetter model. The duration of the process of constrictive cell division (10 min) appeared to be independent of the growth rate for tau equals 60 min or less but to increase with increase doubling time in more slowly growing cells. Physiological division, i.e., compartmentalization prior to physical separation of the cells, was only observed to occur in the last minute of the cell cycle. The morphological results indicate that cell elongation continues during the division process in cells with tau equals 32 min, but fails to continue in cells with tau equals 60 min. Images PMID:1107308

  5. Systematic high-content genome-wide RNAi screens of endothelial cell migration and morphology

    PubMed Central

    Williams, Steven P.; Gould, Cathryn M.; Nowell, Cameron J.; Karnezis, Tara; Achen, Marc G.; Simpson, Kaylene J.; Stacker, Steven A.

    2017-01-01

    Many cell types undergo migration during embryogenesis and disease. Endothelial cells line blood vessels and lymphatics, which migrate during development as part of angiogenesis, lymphangiogenesis and other types of vessel remodelling. These processes are also important in wound healing, cancer metastasis and cardiovascular conditions. However, the molecular control of endothelial cell migration is poorly understood. Here, we present a dataset containing siRNA screens that identify known and novel components of signalling pathways regulating migration of lymphatic endothelial cells. These components are compared to signalling in blood vascular endothelial cells. Further, using high-content microscopy, we captured a dataset of images of migrating cells following transfection with a genome-wide siRNA library. These datasets are suitable for the identification and analysis of genes involved in endothelial cell migration and morphology, and for computational approaches to identify signalling networks controlling the migratory response and integration of cell morphology, gene function and cell signaling. This may facilitate identification of protein targets for therapeutically modulating angiogenesis and lymphangiogenesis in the context of human disease. PMID:28248931

  6. Effects of temperature and cellular interactions on the mechanics and morphology of human cancer cells investigated by atomic force microscopy.

    PubMed

    Li, Mi; Liu, LianQing; Xi, Ning; Wang, YueChao; Xiao, XiuBin; Zhang, WeiJing

    2015-09-01

    Cell mechanics plays an important role in cellular physiological activities. Recent studies have shown that cellular mechanical properties are novel biomarkers for indicating the cell states. In this article, temperature-controllable atomic force microscopy (AFM) was applied to quantitatively investigate the effects of temperature and cellular interactions on the mechanics and morphology of human cancer cells. First, AFM indenting experiments were performed on six types of human cells to investigate the changes of cellular Young's modulus at different temperatures and the results showed that the mechanical responses to the changes of temperature were variable for different types of cancer cells. Second, AFM imaging experiments were performed to observe the morphological changes in living cells at different temperatures and the results showed the significant changes of cell morphology caused by the alterations of temperature. Finally, by co-culturing human cancer cells with human immune cells, the mechanical and morphological changes in cancer cells were investigated. The results showed that the co-culture of cancer cells and immune cells could cause the distinct mechanical changes in cancer cells, but no significant morphological differences were observed. The experimental results improved our understanding of the effects of temperature and cellular interactions on the mechanics and morphology of cancer cells.

  7. Advanced Manufacturing Technologies (AMT): Additive Manufactured Hot Fire Planning and Testing in GRC Cell 32 Project

    NASA Technical Reports Server (NTRS)

    Fikes, John C.

    2014-01-01

    The objective of this project is to hot fire test an additively manufactured thrust chamber assembly TCA (injector and thrust chamber). GRC will install the additively manufactured Inconel 625 injector, two additively manufactured (SLM) water cooled Cu-Cr thrust chamber barrels and one additively manufactured (SLM) water cooled Cu-Cr thrust chamber nozzle on the test stand in Cell 32 and perform hot fire testing of the integrated TCA.

  8. Effects of tacrolimus on morphology, proliferation and differentiation of mesenchymal stem cells derived from gingiva tissue

    PubMed Central

    HA, DONG-HO; YONG, CHUL SOON; KIM, JONG OH; JEONG, JEE-HEON; PARK, JUN-BEOM

    2016-01-01

    Tacrolimus is a 23-membered macrolide lactone with potent immunosuppressive activity that is effective in the prophylaxis of organ rejection following kidney, heart and liver transplantation. Tacrolimus also exerts a variety of actions on bone metabolism. The aim of the present study was to evaluate the effects of different concentrations of tacrolimus on the morphology and viability of human stem cells derived from the gingiva. Gingival-derived stem cells were grown in the presence of tacrolimus at final concentrations ranging from 0.001 to 100 µg/ml. The morphology of the cells was viewed under an inverted microscope and the cell viability was analyzed using Cell Counting kit-8 (CCK-8) on days 1, 3, 5 and 7. Alizarin Red S staining was used to assess mineralization of treated cells. The control group showed spindle-shaped, fibroblast-like morphology and the shapes of the cells in 0.001, 0.01, 0.1, 1 and 10 µg/ml tacrolimus were similar to those of the control group. All groups except the 100 µg/ml group showed increased cell proliferation over time. Cultures grown in the presence of tacrolimus at 0.001, 0.01, 0.1, 1 and 10 µg/ml were not identified to be significantly different compared with the control at days 1, 3 and 5 using the CCK-8 assays. Increased mineralized deposits were noted with increased incubation time. Treatment with tacrolimus from 0.001 to 1 µg/ml led to an increase in mineralization compared with the control group. Within the limits of this study, tacrolimus at the tested concentrations (ranging from 0.001 to 10 µg/ml) did not result in differences in the viability of stem cells derived from gingiva; however it did enhance osteogenic differentiation of the stem cells. PMID:27177273

  9. A simple ImageJ macro tool for analyzing mitochondrial network morphology in mammalian cell culture.

    PubMed

    Valente, Andrew J; Maddalena, Lucas A; Robb, Ellen L; Moradi, Fereshteh; Stuart, Jeffrey A

    2017-03-14

    Mitochondria exist in a dynamic cycle of fusion and fission whose balance directly influences the morphology of the 'mitochondrial network', a term that encompasses the branched, reticular structure of fused mitochondria as well as the separate, punctate individual organelles within a eukaryotic cell. Over the past decade, the significance of the mitochondrial network has been increasingly appreciated, motivating the development of various approaches to analyze it. Here, we describe the Mitochondrial Network Analysis (MiNA) toolset, a relatively simple pair of macros making use of existing ImageJ plug-ins, allowing for semi-automated analysis of mitochondrial networks in cultured mammalian cells. MiNA is freely available at https://github.com/ScienceToolkit/MiNA. The tool incorporates optional preprocessing steps to enhance the quality of images before converting the images to binary and producing a morphological skeleton for calculating nine parameters to quantitatively capture the morphology of the mitochondrial network. The efficacy of the macro toolset is demonstrated using a sample set of images from SH-SY5Y, C2C12, and mouse embryo fibroblast (MEF) cell cultures treated under different conditions and exhibiting hyperfused, fused, and fragmented mitochondrial network morphologies.

  10. Morphological features of IFN-γ–stimulated mesenchymal stromal cells predict overall immunosuppressive capacity

    PubMed Central

    Klinker, Matthew W.; Marklein, Ross A.; Lo Surdo, Jessica L.; Wei, Cheng-Hong

    2017-01-01

    Human mesenchymal stromal cell (MSC) lines can vary significantly in their functional characteristics, and the effectiveness of MSC-based therapeutics may be realized by finding predictive features associated with MSC function. To identify features associated with immunosuppressive capacity in MSCs, we developed a robust in vitro assay that uses principal-component analysis to integrate multidimensional flow cytometry data into a single measurement of MSC-mediated inhibition of T-cell activation. We used this assay to correlate single-cell morphological data with overall immunosuppressive capacity in a cohort of MSC lines derived from different donors and manufacturing conditions. MSC morphology after IFN-γ stimulation significantly correlated with immunosuppressive capacity and accurately predicted the immunosuppressive capacity of MSC lines in a validation cohort. IFN-γ enhanced the immunosuppressive capacity of all MSC lines, and morphology predicted the magnitude of IFN-γ–enhanced immunosuppressive activity. Together, these data identify MSC morphology as a predictive feature of MSC immunosuppressive function. PMID:28283659

  11. How well can morphology assess cell death modality? A proteomics study

    PubMed Central

    Chernobrovkin, Alexey L; Zubarev, Roman A

    2016-01-01

    While the focus of attempts to classify cell death programs has finally shifted in 2010s from microscopy-based morphological characteristics to biochemical assays, more recent discoveries have put the underlying assumptions of many such assays under severe stress, mostly because of the limited specificity of the assays. On the other hand, proteomics can quantitatively measure the abundances of thousands of proteins in a single experiment. Thus proteomics could develop a modern alternative to both semiquantitative morphology assessment as well as single-molecule biochemical assays. Here we tested this hypothesis by analyzing the proteomes of cells dying after been treated with various chemical agents. The most striking finding is that, for a multivariate model based on the proteome changes in three cells lines, the regulation patterns of the 200–500 most abundant proteins typically attributed to household type more accurately reflect that of the proteins directly interacting with the drug than any other protein subset grouped by common function or biological process, including cell death. This is in broad agreement with the 'rigid cell death mechanics' model where drug action mechanism and morphological changes caused by it are bijectively linked. This finding, if confirmed, will open way for a broad use of proteomics in death modality assessment. PMID:27752363

  12. Hsp90 mediates the crosstalk between galactose metabolism and cell morphology pathways in yeast.

    PubMed

    Gopinath, Rajaneesh Karimpurath; Leu, Jun-Yi

    2017-02-01

    Galactose metabolism in the yeast Saccharomyces cerevisiae is carried out by a specialized GAL pathway consisting of structural and regulatory proteins. It is known that cells with unbalanced Gal proteins accumulate toxic metabolic intermediates and exhibit severe growth defects. Recently, we found that the molecular chaperone Hsp90 controls the abundance of multiple Gal proteins, possibly to prevent these defects. Hsp90 regulates various cellular processes including cell morphology in response to environmental cues. Yeast cells are known to resort to filamentous growth upon exposure to galactose or other environmental stresses. Our previous and current findings support the "Hsp90 titration model" of Hsp90 buffering, which links the cell morphology and galactose pathways. Our results suggest that, when a large proportion of Hsp90 molecules are used to help Gal proteins, the Hsp90 client proteins in cell morphology pathways are left unattended, leading to filamentous growth. It remains unclear whether this phenomenon serves any biological function or simply reflects a cellular constraint. Nonetheless, it provides an alternative explanation why the GAL pathway is degenerated in some yeast species.

  13. Cell morphology of extrusion foamed poly(lactic acid) using endothermic chemical foaming agent.

    PubMed

    Matuana, Laurent M; Faruk, Omar; Diaz, Carlos A

    2009-12-01

    Poly(lactic acid) (PLA) was foamed with an endothermic chemical foaming agent (CFA) through an extrusion process. The effects of polymer melt flow index, CFA content, and processing speed on the cellular structures, void fraction, and cell-population density of foamed PLA were investigated. The apparent melt viscosity of PLA was measured to understand the effect of melt index on the cell morphology of foamed PLA samples. The void fraction was strongly dependent on the PLA melt index. It increased with increasing melt index, reaching a maximum value, after which it decreased. Melt index showed no significant effect on the cell-population density of foamed samples within the narrow range studied. A gas containment limit was observed in PLA foamed with CFA. Both the void fraction and cell-population density increased with an initial increase in CFA content, reached a maximum value, and then decreased as CFA content continued to increase. The processing speed also affected the morphology of PLA foams. The void fraction reached a maximum value as the extruder's screw speed increased to 40 rpm and a further increase in the processing speed tended to reduce the void fraction of foamed samples. By contrast, cell-population density increased one order of magnitude by increasing the screw speed from 20 to 120 rpm. The experimental results indicate that a homogeneous and finer cellular morphology could be successfully achieved in PLA foamed in an extrusion process with a proper combination of polymer melt flow index, CFA content, and processing speed.

  14. A two-stage morphological classifier of foci occurring in cell transformation assays

    NASA Astrophysics Data System (ADS)

    Crosta, Giovanni F.; Urani, Chiara; Bussinelli, Luca

    2009-02-01

    Cell Transformation Assays (CTA) rely on the detection of phenotypic changes, namely foci, induced by chemicals (e.g., xenobiotics or candidate drugs) in mammalian cells such as C3H10T1/2 mouse fibroblasts. A focus is a cell colony and as such is made visible by standardized techniques of light microscopy. Foci exhibit a variety of morphological features, by which three "Types" have been defined. Types II and III consist of cells having undergone neoplastic transformation. The assignment of a focus to a Type is based on the evaluation of phenotypic features by a trained human expert. An automated, two-stage morphological classifier of foci is described herewith. Morphological descriptors are extracted from light microscope images by the "spectrum enhancement" algorithm, which separates structure from texture. Said descriptors are submitted to a classifier, the first stage of which is trained to discriminate transformed cells from normal ones and the 2nd stage to discriminate Type III from Type II. The classifier operating in recognition mode (on images not used for training) is satisfactory in terms of confusion matrix entries. The whole procedure is aimed at removing subjectivity from the scoring and classification of foci and thus make CTA a more powerful tool in carcinogenesis studies.

  15. The selective role of ECM components on cell adhesion, morphology, proliferation and communication in vitro.

    PubMed

    Schlie-Wolter, Sabrina; Ngezahayo, Anaclet; Chichkov, Boris N

    2013-06-10

    Cell binding to the extracellular matrix (ECM) is essential for cell and tissue functions. In this context, each tissue consists of a unique ECM composition, which may be responsible for tissue-specific cell responses. Due to the complexity of ECM-cell interactions-which depend on the interplay of inside-out and outside-in signaling cascades, cell and tissue specificity of ECM-guidance is poorly understood. In this paper, we investigate the role of different ECM components like laminin, fibronectin, and collagen type I with respect to the essential cell behaviour patterns: attachment dynamics such as adhesion kinetic and force, formation of focal adhesion complexes, morphology, proliferation, and intercellular communication. A detailed in vitro comparison of fibroblasts, endothelial cells, osteoblasts, smooth muscle cells, and chondrocytes reveals significant differences in their cell responses to the ECM: cell behaviour follows a cell specific ligand priority ranking, which was independent of the cell type origin. Fibroblasts responded best to fibronectin, chondrocytes best to collagen I, the other cell types best to laminin. This knowledge is essential for optimization of tissue-biomaterial interfaces in all tissue engineering applications and gives insight into tissue-specific cell guidance.

  16. Repressed synthesis of ribosomal proteins generates protein-specific cell cycle and morphological phenotypes.

    PubMed

    Thapa, Mamata; Bommakanti, Ananth; Shamsuzzaman, Md; Gregory, Brian; Samsel, Leigh; Zengel, Janice M; Lindahl, Lasse

    2013-12-01

    The biogenesis of ribosomes is coordinated with cell growth and proliferation. Distortion of the coordinated synthesis of ribosomal components affects not only ribosome formation, but also cell fate. However, the connection between ribosome biogenesis and cell fate is not well understood. To establish a model system for inquiries into these processes, we systematically analyzed cell cycle progression, cell morphology, and bud site selection after repression of 54 individual ribosomal protein (r-protein) genes in Saccharomyces cerevisiae. We found that repression of nine 60S r-protein genes results in arrest in the G2/M phase, whereas repression of nine other 60S and 22 40S r-protein genes causes arrest in the G1 phase. Furthermore, bud morphology changes after repression of some r-protein genes. For example, very elongated buds form after repression of seven 60S r-protein genes. These genes overlap with, but are not identical to, those causing the G2/M cell cycle phenotype. Finally, repression of most r-protein genes results in changed sites of bud formation. Strikingly, the r-proteins whose repression generates similar effects on cell cycle progression cluster in the ribosome physical structure, suggesting that different topological areas of the precursor and/or mature ribosome are mechanistically connected to separate aspects of the cell cycle.

  17. Control over the morphology and segregation of Zebrafish germ cell granules during embryonic development

    PubMed Central

    Strasser, Markus J; Mackenzie, Natalia C; Dumstrei, Karin; Nakkrasae, La-Iad; Stebler, Jürg; Raz, Erez

    2008-01-01

    Background Zebrafish germ cells contain granular-like structures, organized around the cell nucleus. These structures share common features with polar granules in Drosophila, germinal granules in Xenopus and chromatoid bodies in mice germ cells, such as the localization of the zebrafish Vasa, Piwi and Nanos proteins, among others. Little is known about the structure of these granules as well as their segregation in mitosis during early germ-cell development. Results Using transgenic fish expressing a fluorescently labeled novel component of Zebrafish germ cell granules termed Granulito, we followed the morphology and distribution of the granules. We show that whereas these granules initially exhibit a wide size variation, by the end of the first day of development they become a homogeneous population of medium size granules. We investigated this resizing event and demonstrated the role of microtubules and the minus-end microtubule dependent motor protein Dynein in the process. Last, we show that the function of the germ cell granule resident protein the Tudor domain containing protein-7 (Tdrd7) is required for determination of granule morphology and number. Conclusion Our results suggest that Zebrafish germ cell granules undergo a transformation process, which involves germ cell specific proteins as well as the microtubular network. PMID:18507824

  18. EVALUATION OF BENZO[C]CHRYSENE DIHYDRODIOLS IN THE MORPHOLOGICAL CELL TRANSFORMATION OF MOUSE EMBRYO FIBROBLAST C3H10T1/2CL8 CELLS

    EPA Science Inventory

    EVALUATION OF BENZO[c]CHRYSENE DIHYDRODIOLS IN THE MORPHOLOGICAL CELL TRANSFORMATION OF MOUSE EMBRYO FIBROBLAST C3H10T?CL8 CELLS

    Abstract The morphological cell transforming activities of three dihydrodiols of benzo[c]chrysene (B[c]C), trans-B[c]C-7,8-diol, trans-B[c]C-9...

  19. Investigation on 3D morphological changes of in vitro cells through digital holographic microscopy

    NASA Astrophysics Data System (ADS)

    Memmolo, Pasquale; Miccio, Lisa; Merola, Francesco; Netti, Paolo A.; Coppola, Giuseppe; Ferraro, Pietro

    2013-04-01

    We report the investigation of the identification and measurement of region of interest (ROI) in quantitative phase-contrast maps (QPMs) of biological cells by digital holographic microscopy (DHM), with the aim to analyze the 3D positions and 3D morphology together. We consider as test case for our tool the in vitro bull sperm head morphometry analysis. Extraction and measurement of various morphological parameters are performed by using two methods: the anisotropic diffusion filter, that is based on the Gaussian diffusivity function which allows more accuracy of the edge position, and the simple thresholding filter. In particular we consider the calculation of area, ellipticity, perimeter, major axis, minor axis and shape factor as a morphological parameter, instead, for the estimation of 3D position, we compute the centroid, the weighted centroid and the maximum phase values. A statistical analysis on a data set composed by N = 14 holograms relative to bovine spermatozoa and its reference holograms is reported.

  20. You are what you talk: quorum sensing induces individual morphologies and cell division modes in Dinoroseobacter shibae.

    PubMed

    Patzelt, Diana; Wang, Hui; Buchholz, Ina; Rohde, Manfred; Gröbe, Lothar; Pradella, Silke; Neumann, Alexander; Schulz, Stefan; Heyber, Steffi; Münch, Karin; Münch, Richard; Jahn, Dieter; Wagner-Döbler, Irene; Tomasch, Jürgen

    2013-12-01

    Dinoroseobacter shibae, a member of the Roseobacter clade abundant in marine environments, is characterized by a pronounced pleomorphism. Cell shapes range from variable-sized ovoid rods to long filaments with a high copy number of chromosomes. Time-lapse microscopy shows cells dividing either by binary fission or by budding from the cell poles. Here we demonstrate that this morphological heterogeneity is induced by quorum sensing (QS). D. shibae utilizes three acylated homoserine lactone (AHL) synthases (luxI1-3) to produce AHLs with unsaturated C18 side chains. A ΔluxI1-knockout strain completely lacking AHL biosynthesis was uniform in morphology and divided by binary fission only. Transcriptome analysis revealed that expression of genes responsible for control of cell division was reduced in this strain, providing the link between QS and the observed phenotype. In addition, flagellar biosynthesis and type IV secretion system (T4SS) were downregulated. The wild-type phenotype and gene expression could be restored through addition of synthetic C18-AHLs. Their effectiveness was dependent on the number of double bonds in the acyl side chain and the regulated trait. The wild-type expression level of T4SS genes was fully restored even by an AHL with a saturated C18 side chain that has not been detected in D. shibae. QS induces phenotypic individualization of D. shibae cells rather than coordinating the population. This strategy might be beneficial in unpredictably changing environments, for example, during algal blooms when resource competition and grazing exert fluctuating selective pressures. A specific response towards non-native AHLs might provide D. shibae with the capacity for complex interspecies communication.

  1. Morphological and biochemical characterization of mitochondria in Torpedo red blood cells.

    PubMed

    Pica, A; Scacco, S; Papa, F; De Nitto, E; Papa, S

    2001-02-01

    A study is presented on the morphology and respiratory functions of mitochondria from Torpedo marmorata red blood cells. In vivo staining of red blood cells and transmission electron microscopy showed the existence of a considerable number of vital and orthodox mitochondria which decreased from young erythroblasts to mature erythrocytes from 60-50 to 30-20 per cell. In erythrocytes mitochondria exhibited a canonical, functional respiratory chain. The content and activity of cytochromes in erythrocytes were, however, significantly lower as compared to mammalian tissues.

  2. Supervised classification of etoposide-treated in vitro adherent cells based on noninvasive imaging morphology.

    PubMed

    Mölder, Anna Leida; Persson, Johan; El-Schich, Zahra; Czanner, Silvester; Gjörloff-Wingren, Anette

    2017-04-01

    Single-cell studies using noninvasive imaging is a challenging, yet appealing way to study cellular characteristics over extended periods of time, for instance to follow cell interactions and the behavior of different cell types within the same sample. In some cases, e.g., transplantation culturing, real-time cellular monitoring, stem cell studies, in vivo studies, and embryo growth studies, it is also crucial to keep the sample intact and invasive imaging using fluorophores or dyes is not an option. Computerized methods are needed to improve throughput of image-based analysis and for use with noninvasive microscopy such methods are poorly developed. By combining a set of well-documented image analysis and classification tools with noninvasive microscopy, we demonstrate the ability for long-term image-based analysis of morphological changes in single cells as induced by a toxin, and show how these changes can be used to indicate changes in biological function. In this study, adherent cell cultures of DU-145 treated with low-concentration (LC) etoposide were imaged during 3 days. Single cells were identified by image segmentation and subsequently classified on image features, extracted for each cell. In parallel with image analysis, an MTS assay was performed to allow comparison between metabolic activity and morphological changes after long-term low-level drug response. Results show a decrease in proliferation rate for LC etoposide, accompanied by changes in cell morphology, primarily leading to an increase in cell area and textural changes. It is shown that changes detected by image analysis are already visible on day 1 for [Formula: see text] etoposide, whereas effects on MTS and viability are detected only on day 3 for [Formula: see text] etoposide concentration, leading to the conclusion that the morphological changes observed occur before and at lower concentrations than a reduction in cell metabolic activity or viability. Three classifiers are compared and we

  3. Morphological characteristics of blood cells in monitor lizards: is erythrocyte size linked to actual body size?

    PubMed

    Frýdlová, Petra; Hnízdo, Jan; Chylíková, Lenka; Simková, Olga; Cikánová, Veronika; Velenský, Petr; Frynta, Daniel

    2013-04-01

    Blood cell morphology and count are not uniform across species. Recently, between-species comparisons revealed that the size of red blood cells is associated with body size in some lizard taxa, and this finding was interpreted in the context of the metabolic theory. In the present study, we examined the numbers and the size of blood cells in 2 species of monitor lizards, the mangrove-dwelling monitor (Varanus indicus) and the savannah monitor (V. exanthematicus), and we compared these traits in individuals of different body size. The results revealed that during the course of ontogeny, the size of red blood cells increases with body mass. Because the mass-specific metabolic rate decreases with body size and the cell volume-to-surface ratio decreases with the cell size, changes in the erythrocyte size might be the result of oxygen transport adjustment.

  4. Retinal ganglion cells in the Pacific redfin, Tribolodon brandtii dybowski, 1872: morphology and diversity.

    PubMed

    Pushchin, Igor; Karetin, Yuriy

    2014-04-15

    We studied the morphology and diversity of retinal ganglion cells in the Pacific redfin, Tribolodon brandtii. These cells were retrogradely labeled with horseradish peroxidase and examined in retinal whole mounts. A sample of 203 cells was drawn with a camera lucida. A total of 19 structural parameters were estimated for each cell, and a variety of clustering algorithms were used to classify the cells. The optimal solution was determined by using silhouette analysis. It was based on three variables associated with dendritic field size and dendrite stratification in the retina. Kruskal-Wallis ANOVA-on-ranks with post hoc Mann-Whitney U tests showed significant pairwise between-cluster differences in two or more of the original variables. In total, eight cell types were discovered. The advantages and drawbacks of the methodology adopted are discussed. The present classification is compared with classifications proposed for other teleosts.

  5. The selective role of ECM components on cell adhesion, morphology, proliferation and communication in vitro

    SciTech Connect

    Schlie-Wolter, Sabrina; Ngezahayo, Anaclet; Chichkov, Boris N.

    2013-06-10

    Cell binding to the extracellular matrix (ECM) is essential for cell and tissue functions. In this context, each tissue consists of a unique ECM composition, which may be responsible for tissue-specific cell responses. Due to the complexity of ECM-cell interactions—which depend on the interplay of inside-out and outside-in signaling cascades, cell and tissue specificity of ECM-guidance is poorly understood. In this paper, we investigate the role of different ECM components like laminin, fibronectin, and collagen type I with respect to the essential cell behaviour patterns: attachment dynamics such as adhesion kinetic and force, formation of focal adhesion complexes, morphology, proliferation, and intercellular communication. A detailed in vitro comparison of fibroblasts, endothelial cells, osteoblasts, smooth muscle cells, and chondrocytes reveals significant differences in their cell responses to the ECM: cell behaviour follows a cell specific ligand priority ranking, which was independent of the cell type origin. Fibroblasts responded best to fibronectin, chondrocytes best to collagen I, the other cell types best to laminin. This knowledge is essential for optimization of tissue-biomaterial interfaces in all tissue engineering applications and gives insight into tissue-specific cell guidance. -- Highlights: • We analyse the impact of ECM components on cell behaviour in vitro. • We compare five different cell types, using the same culture conditions. • The ECM significantly guides all cell responses. • Cell behaviour follows a cell specific ligand-priority ranking. • This gives insight in tissue formation and is essential for biomedical applications.

  6. Distinct Morphology of Human T-Cell Leukemia Virus Type 1-Like Particles

    PubMed Central

    Maldonado, José O.; Cao, Sheng; Zhang, Wei; Mansky, Louis M.

    2016-01-01

    The Gag polyprotein is the main retroviral structural protein and is essential for the assembly and release of virus particles. In this study, we have analyzed the morphology and Gag stoichiometry of human T-cell leukemia virus type 1 (HTLV-1)-like particles and authentic, mature HTLV-1 particles by using cryogenic transmission electron microscopy (cryo-TEM) and scanning transmission electron microscopy (STEM). HTLV-1-like particles mimicked the morphology of immature authentic HTLV-1 virions. Importantly, we have observed for the first time that the morphology of these virus-like particles (VLPs) has the unique local feature of a flat Gag lattice that does not follow the curvature of the viral membrane, resulting in an enlarged distance between the Gag lattice and the viral membrane. Other morphological features that have been previously observed with other retroviruses include: (1) a Gag lattice with multiple discontinuities; (2) membrane regions associated with the Gag lattice that exhibited a string of bead-like densities at the inner leaflet; and (3) an arrangement of the Gag lattice resembling a railroad track. Measurement of the average size and mass of VLPs and authentic HTLV-1 particles suggested a consistent range of size and Gag copy numbers in these two groups of particles. The unique local flat Gag lattice morphological feature observed suggests that HTLV-1 Gag could be arranged in a lattice structure that is distinct from that of other retroviruses characterized to date. PMID:27187442

  7. Systematic morphological profiling of human gene and allele function via Cell Painting

    PubMed Central

    Rohban, Mohammad Hossein; Singh, Shantanu; Wu, Xiaoyun; Berthet, Julia B; Bray, Mark-Anthony; Shrestha, Yashaswi; Varelas, Xaralabos; Boehm, Jesse S; Carpenter, Anne E

    2017-01-01

    We hypothesized that human genes and disease-associated alleles might be systematically functionally annotated using morphological profiling of cDNA constructs, via a microscopy-based Cell Painting assay. Indeed, 50% of the 220 tested genes yielded detectable morphological profiles, which grouped into biologically meaningful gene clusters consistent with known functional annotation (e.g., the RAS-RAF-MEK-ERK cascade). We used novel subpopulation-based visualization methods to interpret the morphological changes for specific clusters. This unbiased morphologic map of gene function revealed TRAF2/c-REL negative regulation of YAP1/WWTR1-responsive pathways. We confirmed this discovery of functional connectivity between the NF-κB pathway and Hippo pathway effectors at the transcriptional level, thereby expanding knowledge of these two signaling pathways that critically regulate tumor initiation and progression. We make the images and raw data publicly available, providing an initial morphological map of major biological pathways for future study. DOI: http://dx.doi.org/10.7554/eLife.24060.001 PMID:28315521

  8. Lipophilic organic pollutants induce changes in phospholipid and membrane protein composition leading to Vero cell morphological change.

    PubMed

    Liao, Ting T; Wang, Lei; Jia, Ru W; Fu, Xiao H; Chua, Hong

    2014-01-01

    Membrane damage related to morphological change in Vero cells is a sensitive index of the composite biotoxicity of trace lipophilic chemicals. However, judging whether the morphological change in Vero cells happens and its ratio are difficult because it is not a quantitative characteristic. To find biomarkers of cell morphological change for quantitatively representing the ratio of morphological changed cell, the mechanism of cell membrane damage driven by typical lipophilic chemicals, such as trichlorophenol (TCP) and perfluorooctanesulphonate (PFOS), was explored. The ratio of morphologically changed cells generally increased with increased TCP or PFOS concentrations, and the level of four major components of phospholipids varied with concentrations of TCP or PFOS, but only the ratio of phosphatidylcholine (PC)/phosphatidylethanolamine (PE) decreased regularly as TCP or PFOS concentrations increased. Analysis of membrane proteins showed that the level of vimentin in normal cell membranes is high, while it decreases or vanishes after TCP exposure. These variations in phospholipid and membrane protein components may result in membrane leakage and variation in rigid structure, which leads to changes in cell morphology. Therefore, the ratio of PC/PE and amount of vimentin may be potential biomarkers for representing the ratio of morphological changed Vero cell introduced by trace lipophilic compounds, thus their composite bio-toxicity.

  9. NOTCH2 signaling confers immature morphology and aggressiveness in human hepatocellular carcinoma cells.

    PubMed

    Hayashi, Yoshihiro; Osanai, Makoto; Lee, Gang-Hong

    2015-10-01

    The NOTCH family of membranous receptors plays key roles during development and carcinogenesis. Since NOTCH2, yet not NOTCH1 has been shown essential for murine hepatogenesis, NOTCH2 rather than NOTCH1 may be more relevant to human hepatocarcinogenesis; however, no previous studies have supported this hypothesis. We therefore assessed the role of NOTCH2 in human hepatocellular carcinoma (HCC) by immunohistochemistry and cell culture. Immunohistochemically, 19% of primary HCCs showed nuclear staining for NOTCH2, indicating activated NOTCH2 signaling. NOTCH2-positive HCCs were on average in more advanced clinical stages, and exhibited more immature cellular morphology, i.e. higher nuclear-cytoplasmic ratios and nuclear densities. Such features were not evident in NOTCH1‑positive HCCs. In human HCC cell lines, abundant NOTCH2 expression was associated with anaplasia, represented by loss of E-cadherin. When NOTCH2 signaling was stably downregulated in HLF cells, an anaplastic HCC cell line, the cells were attenuated in potential for in vitro invasiveness and migration, as well as in vivo tumorigenicity accompanied by histological maturation. Generally, inverse results were obtained for a differentiated HCC cell line, Huh7, manipulated to overexpress activated NOTCH2. These findings suggested that the NOTCH2 signaling may confer aggressive behavior and immature morphology in human HCC cells.

  10. Phorbol 12-myristate 13-acetate prevents isoproterenol-induced morphological change in cultured vascular smooth muscle cells

    SciTech Connect

    Nabika, Toru; Chaldakov, G.N.; Nara, Yasuo; Endo, Jiro; Yamori, Yukio )

    1988-10-01

    The effect of phorbol 12-myristate 13-acetate (PMA) on isoproterenol (ISO)- and dibutyryl cAMP (dBcAMP)-induced morphological change and cytoskeletal reorganization was studied in cultured vascular smooth muscle cells (VSMC) using the fluorescence staining of actin and microtubules. The treatment of VSMC with 1.0 {mu}M of ISO or with 1.0 mM of dBcAMP for 90 min induced the disruption of actin-containing stress fibers followed by cytoplasmic arborization. The addition of 100 nM of PMA prevented both the destruction of actin fibers and cell arborization induced either by ISO or by dBcAMP. These results indicated that the inhibition of arborization by PMA was mediated through the activation of protein kinase C. Colchicine at 5.0 {mu}M also had an inhibitory effect on ISO- and dBcAMP-induced cell arborization. However, immunofluorescence studies revealed that colchicine but not PMA elicited the reorganization of microtubules, suggesting that the effect of PMA was mediated through a mechanism different from that of colchicine. The observations indicated that the morphology of VSMC was regulated through the alteration of cytoskeletal organization induced by cAMP-mediated and by protein kinase C-dependent systems.

  11. The morphologies of breast cancer cell lines in three-dimensionalassays correlate with their profiles of gene expression

    SciTech Connect

    Kenny, Paraic A.; Lee, Genee Y.; Myers, Connie A.; Neve, RichardM.; Semeiks, Jeremy R.; Spellman, Paul T.; Lorenz, Katrin; Lee, Eva H.; Barcellos-Hoff, Mary Helen; Petersen, Ole W.; Gray, Joe W.; Bissell, MinaJ.

    2007-01-31

    3D cell cultures are rapidly becoming the method of choice for the physiologically relevant modeling of many aspects of non-malignant and malignant cell behavior ex vivo. Nevertheless, only a limited number of distinct cell types have been evaluated in this assay to date. Here we report the first large scale comparison of the transcriptional profiles and 3D cell culture phenotypes of a substantial panel of human breast cancer cell lines. Each cell line adopts a colony morphology of one of four main classes in 3D culture. These morphologies reflect, at least in part, the underlying gene expression profile and protein expression patterns of the cell lines, and distinct morphologies were also associated with tumor cell invasiveness and with cell lines originating from metastases. We further demonstrate that consistent differences in genes encoding signal transduction proteins emerge when even tumor cells are cultured in 3D microenvironments.

  12. Metal-air cell comprising an electrolyte with a room temperature ionic liquid and hygroscopic additive

    DOEpatents

    Friesen, Cody A.; Krishnan, Ramkumar; Tang, Toni; Wolfe, Derek

    2014-08-19

    An electrochemical cell comprising an electrolyte comprising water and a hydrophobic ionic liquid comprising positive ions and negative ions. The electrochemical cell also includes an air electrode configured to absorb and reduce oxygen. A hydrophilic or hygroscopic additive modulates the hydrophobicity of the ionic liquid to maintain a concentration of the water in the electrolyte is between 0.001 mol % and 25 mol %.

  13. Glucocorticoid receptor blockade inhibits brain cell addition and aggressive signaling in electric fish, Apteronotus leptorhynchus.

    PubMed

    Dunlap, Kent D; Jashari, Denisa; Pappas, Kristina M

    2011-08-01

    When animals are under stress, glucocorticoids commonly inhibit adult neurogenesis by acting through glucocorticoid receptors (GRs). However, in some cases, conditions that elevate glucocorticoids promote adult neurogenesis, and the role of glucocorticoid receptors in these circumstances is not well understood. We examined the involvement of GRs in social enhancement of brain cell addition and aggressive signaling in electric fish, Apteronotus leptorhynchus. In this species, long-term social interaction simultaneously elevates plasma cortisol, enhances brain cell addition and increases production of aggressive electrocommunication signals ("chirps"). We implanted isolated and paired fish with capsules containing nothing (controls) or the GR antagonist, RU486, recorded chirp production and locomotion for 7d, and measured the density of newborn cells in the periventricular zone. Compared to isolated controls, paired controls showed elevated chirping in two phases: much higher chirp rates in the first 5h and moderately higher nocturnal rates thereafter. Treating paired fish with RU486 reduced chirp rates in both phases to those of isolated fish, demonstrating that GR activation is crucial for socially induced chirping. Neither RU486 nor social interaction affected locomotion. RU486 treatment to paired fish had a partial effect on cell addition: paired RU486 fish had less cell addition than paired control fish but more than isolated fish. This suggests that cortisol activation of GRs contributes to social enhancement of cell addition but works in parallel with another GR-independent mechanism. RU486 also reduced cell addition in isolated fish, indicating that GRs participate in the regulation of cell addition even when cortisol levels are low.

  14. Mechanical and Electrical Behavior of Organic Solar Cells Probed Through Detailed Morphological Control

    NASA Astrophysics Data System (ADS)

    Awartani, Omar Marwan

    One of the main advantages of organic solar cells is their potential to be used in flexible or even stretchable applications. Most research in the field of organic solar cells is focused on materials synthesis, device physics, and the relationship between morphology and the optoelectronic performance. In order for this technology to be commercially competitive, especially for flexible applications, a more complete picture that explores the mechanical properties of organic materials and how they relate to their optoelectronic properties is necessary. This thesis consists of two main research tracks: The first track focuses mainly on the effect of morphology on the mechanical, electrical and optical performance of organic solar cells controlled through varying processing conditions. Two mechanical properties are investigated including the elastic modulus and crack onset strain of P3HT, PCBM and blend (BHJ) films. The second track utilizes the high achievable ductility of organic semiconducting films that is investigated in the first track of the thesis, to create novel solar cell device architectures and to gain insight into the performance and recombination losses of organic solar cells. Processing ductile BHJ films is used to create organic solar cells with controlled level of polarization with both opaque and semi-transparent architectures. Moreover, using the strain-alignment method the efficiency of low and high order P3HT aggregates is probed within the same film to show similar internal quantum efficiency for the two different morphological P3HT domains. This selective probing technique provides significant insight into performance loss mechanisms in organic solar cells.

  15. Toker cells of the breast. Morphological and immunohistochemical characterization of 40 cases.

    PubMed

    Di Tommaso, Luca; Franchi, Giada; Destro, Annarita; Broglia, Fabiana; Minuti, Francesco; Rahal, Daoud; Roncalli, Massimo

    2008-09-01

    Toker cells are epithelial cells with clear cytoplasm usually free of cytologic atypia localized within the nipple epidermis. Rarely, they can be so numerous and atypical as to require a careful distinction from malignant cells of Paget's disease. The purpose of this paper was to better define the prevalence of these atypical Toker cells and to investigate phenotypic markers that can be helpful in the differential diagnosis with Paget's disease. Forty cases containing Toker cells were identified in the nipples of 390 patients (10.2%) who underwent complete breast mastectomy. In 24 cases (60%), Toker cells were cytologically bland and benign, disappearing after a few consecutive sections ("normal Toker cells"). In 11 cases (27.5%), Toker cells were more numerous and persistent on serial sections, still retaining bland cytologic features ("hyperplastic Toker cells"). In 5 cases (12.5%), hyperplastic Toker cells also became cytologically atypical ("hyperplastic and atypical Toker cells"). On immunohistochemistry, Toker cells were positive for estrogen (25/25) and progesterone (20/23) receptors, and negative for CD138 (18/19) and p53 (14/14); some hyperplastic and atypical Toker cells (4 cases) and hyperplastic Toker cells (1 case) showed faint immunoreactivity for HER2/NEU. For comparison, Paget's disease were negative for estrogen (6/10) and progesterone (7/10) receptors, and positive for CD138 (7/10), p53 (6/10), and HER2/NEU (9/10). Both Toker cells and Paget's disease stained positive for cytokeratin 7 and epithelial membrane antigen, and negative for p63. In conclusion, Toker cells are detectable in 10% of the nipples and are usually cytologically bland, but in 10% of the cases they can be morphologically atypical. The combined use of CD138/p53 is very helpful in distinguishing these atypical Toker cells from those of Paget's disease.

  16. Biocompatible mesoporous silica nanoparticles with different morphologies for animal cell membrane penetration

    SciTech Connect

    Trewyn, B.; Nieweg, J.; Zhao, Y,; Lin, V.

    2007-11-24

    Two MCM-41 type, fluorescein-labeled mesoporous silica nanomaterials (MSNs) consisting of spherical and tube-shaped particles were synthesized and characterized. Both materials have hexagonally arranged mesopores with high surface area (>950 m{sup 2}/g) and a narrow distribution of pore diameters. The cellular uptake efficiency and kinetics of both MSNs were measured in a cancer cell line (CHO) and a noncancerous cell line (fibroblasts) by flow cytometry and fluorescence confocal microscopy. The correlation between the particle morphology and aggregation of MSNs to the effectiveness of cellular uptake was investigated. We envision that our study on the morphology dependent endocytosis of MSNs would lead to future developments of efficient transmembrane nanodevices for intracellular sensing and gene/drug delivery.

  17. Glioma grading using cell nuclei morphologic features in digital pathology images

    NASA Astrophysics Data System (ADS)

    Reza, Syed M. S.; Iftekharuddin, Khan M.

    2016-03-01

    This work proposes a computationally efficient cell nuclei morphologic feature analysis technique to characterize the brain gliomas in tissue slide images. In this work, our contributions are two-fold: 1) obtain an optimized cell nuclei segmentation method based on the pros and cons of the existing techniques in literature, 2) extract representative features by k-mean clustering of nuclei morphologic features to include area, perimeter, eccentricity, and major axis length. This clustering based representative feature extraction avoids shortcomings of extensive tile [1] [2] and nuclear score [3] based methods for brain glioma grading in pathology images. Multilayer perceptron (MLP) is used to classify extracted features into two tumor types: glioblastoma multiforme (GBM) and low grade glioma (LGG). Quantitative scores such as precision, recall, and accuracy are obtained using 66 clinical patients' images from The Cancer Genome Atlas (TCGA) [4] dataset. On an average ~94% accuracy from 10 fold crossvalidation confirms the efficacy of the proposed method.

  18. Glioma Grading Using Cell Nuclei Morphologic Features in Digital Pathology Images

    PubMed Central

    Reza, Syed M. S.; Iftekharuddin, Khan M.

    2016-01-01

    This work proposes a computationally efficient cell nuclei morphologic feature analysis technique to characterize the brain gliomas in tissue slide images. In this work, our contributions are two-fold: 1) obtain an optimized cell nuclei segmentation method based on the pros and cons of the existing techniques in literature, 2) extract representative features by k-mean clustering of nuclei morphologic features to include area, perimeter, eccentricity, and major axis length. This clustering based representative feature extraction avoids shortcomings of extensive tile [1] [2] and nuclear score [3] based methods for brain glioma grading in pathology images. Multilayer perceptron (MLP) is used to classify extracted features into two tumor types: glioblastoma multiforme (GBM) and low grade glioma (LGG). Quantitative scores such as precision, recall, and accuracy are obtained using 66 clinical patients’ images from The Cancer Genome Atlas (TCGA) [4] dataset. On an average ~94% accuracy from 10 fold cross-validation confirms the efficacy of the proposed method. PMID:27942094

  19. Morphological and physiological evidence for interstitial cell of Cajal-like cells in the guinea pig gallbladder.

    PubMed

    Lavoie, Brigitte; Balemba, Onesmo B; Nelson, Mark T; Ward, Sean M; Mawe, Gary M

    2007-03-01

    Gallbladder smooth muscle (GBSM) exhibits spontaneous rhythmic electrical activity, but the origin and propagation of this activity are not understood. We used morphological and physiological approaches to determine whether interstitial cells of Cajal (ICC) are present in the guinea pig extrahepatic biliary tree. Light microscopic studies involving Kit tyrosine kinase immunohistochemistry and laser confocal imaging of Ca(2+) transients revealed ICC-like cells in the gallbladder. One type of ICC-like cell had elongated cell bodies with one or two primary processes and was observed mainly along GBSM bundles and nerve fibres. The other type comprised multipolar cells that were located at the origin and intersection of muscle bundles. Electron microscopy revealed ICC-like cells that were rich in mitochondria, caveolae and smooth endoplasmic reticulum and formed close appositions between themselves and with GBSM cells. Rhythmic Ca(2+) flashes, which represent Ca(2+) influx during action potentials, were synchronized in any given GBSM bundle and associated ICC-like cells. Gap junction uncouplers (1-octanol, carbenoxolone, 18beta-glycyrrhetinic acid and connexin mimetic peptide) eliminated or greatly reduced Ca(2+) flashes in GBSM, but they persisted in ICC-like cells, whereas the Kit tyrosine kinase inhibitor, imanitib mesylate, eliminated or reduced action potentials and Ca(2+) flashes in both cell types, as well as associated tissue contractions. This study provides morphological and physiological evidence for the existence of ICC-like cells in the gallbladder and presents data supporting electrical coupling between ICC-like and GBSM cells. The results support a role for ICC-like cells in the generation and propagation of spontaneous rhythmicity, and hence, the excitability of gallbladder.

  20. Rapid morphological oscillation of mitochondrion-rich cell in estuarine mudskipper following salinity changes.

    PubMed

    Sakamoto, T; Yokota, S; Ando, M

    2000-05-01

    Morphological changes in the chloride cells or mitochondrion-rich (MR) cells in the skin under the pectoral fin of the estuarine mudskipper (Periophthalmus modestus) were examined in relation to intertidal salinity oscillation in river mouth. MR cells were distinguished between those in contact with the water (cells labeled with both mitochondrial probe DASPEI and Concanavalin-A, an apical surface marker of MR cells) and those that are not (DASPEI-positive only). After transfer of the fish from seawater to freshwater, no difference in the total MR cell density was observed, but the subpopulation of MR cells that are Concanavalin-A-positive decreased dramatically within 30 min. After 6 hr in freshwater, the fish were returned to seawater; the number of Con-A-positive MR cells increased to the initial levels rapidly. Thus, in seawater, mudskippers seem to open the apical crypts of the MR cells to secrete salt; in freshwater, they close the crypt of the MR cells tentatively, and tolerate hypotonicity until the rising tide. This unique response of chloride cells may also be seen in gills of other estuarine species.

  1. Stabilization of gene expression and cell morphology after explant recycling during fin explant culture in goldfish.

    PubMed

    Chenais, Nathalie; Lareyre, Jean-Jacques; Le Bail, Pierre-Yves; Labbe, Catherine

    2015-07-01

    The development of fin primary cell cultures for in vitro cellular and physiological studies is hampered by slow cell outgrowth, low proliferation rate, poor viability, and sparse cell characterization. Here, we investigated whether the recycling of fresh explants after a first conventional culture could improve physiological stability and sustainability of the culture. The recycled explants were able to give a supplementary cell culture showing faster outgrowth, cleaner cell layers and higher net cell production. The cells exhibited a highly stabilized profile for marker gene expression including a low cytokeratin 49 (epithelial marker) and a high collagen 1a1 (mesenchymal marker) expression. Added to the cell spindle-shaped morphology, motility behavior, and actin organization, this suggests that the cells bore stable mesenchymal characteristics. This contrast with the time-evolving expression pattern observed in the control fresh explants during the first 2 weeks of culture: a sharp decrease in cytokeratin 49 expression was concomitant with a gradual increase in col1a1. We surmise that such loss of epithelial features for the benefit of mesenchymal ones was triggered by an epithelial to mesenchymal transition (EMT) process or by way of a progressive population replacement process. Overall, our findings provide a comprehensive characterization of this new primary culture model bearing mesenchymal features and whose stability over culture time makes those cells good candidates for cell reprogramming prior to nuclear transfer, in a context of fish genome preservation.

  2. Effect of non-solvent additives on the morphology, pore structure, and direct contact membrane distillation performance of PVDF-CTFE hydrophobic membranes.

    PubMed

    Zheng, Libing; Wu, Zhenjun; Zhang, Yong; Wei, Yuansong; Wang, Jun

    2016-07-01

    Four common types of additives for polymer membrane preparation including organic macromolecule and micromolecule additives, inorganic salts and acids, and the strong non-solvent H2O were used to prepare poly (vinylidene fluoride-co-chlorotrifluoroethylene) (PVDF-CTFE) hydrophobic flat-sheet membranes. Membrane properties including morphology, porosity, hydrophobicity, pore size and pore distribution were investigated, and the permeability was evaluated via direct contact membrane distillation (DCMD) of 3.5g/L NaCl solution in a DCMD configuration. Both inorganic and organic micromolecule additives were found to slightly influence membrane hydrophobicity. Polyethylene glycol (PEG), organic acids, LiCl, MgCl2, and LiCl/H2O mixtures were proved to be effective additives to PVDF-CTFE membranes due to their pore-controlling effects and the capacity to improve the properties and performance of the resultant membranes. The occurrence of a pre-gelation process showed that when organic and inorganic micromolecules were added to PVDF-CTFE solution, the resultant membranes presented a high interconnectivity structure. The membrane prepared with dibutyl phthalate (DBP) showed a nonporous surface and symmetrical cross-section. When H2O and LiCl/H2O mixtures were also used as additives, they were beneficial for solid-liquid demixing, especially when LiCl/H2O mixed additives were used. The membrane prepared with 5% LiCl+2% H2O achieved a flux of 24.53kg/(m(2)·hr) with 99.98% salt rejection. This study is expected to offer a reference not only for PVDF-CTFE membrane preparation but also for other polymer membranes.

  3. Endothelial Cell Morphology and Migration are Altered by Changes in Gravitational Fields

    NASA Technical Reports Server (NTRS)

    Melhado, Caroline; Sanford, Gary; Harris-Hooker, Sandra

    1997-01-01

    Endothelial cell migration is important to vascular wall regeneration following injury or stress. However, the mechanism(s) governing this response is not well understood. The microgravity environment of space may complicate the response of these cells to injury. To date, there are no reports in this area. We examined how bovine aortic (BAEC) and pulmonary (BPEC) endothelial cells respond to denudation injury under hypergravity (HGrav) and simulated microgravity (MGrav), using image analysis. In 10% FBS, the migration of confluent BAEC and BPEC into the denuded area was not affected by HGrav or MGrav. However, in low FBS (0.5%), signficantly retarded migration under MGrav, and increased migration under HGrav was found. MGrav also decreased the migration of postconfluent BPEC while HGrav showed no difference. Both MGrav and HGrav strongly decreased the migration of postconfluent BAEC. Also, both cell lines showed significant morphological changes by scanning electron microscopy. These studies indicate that endothelial cell function is affected by changes in gravity.

  4. Gene Therapy Restores Hair Cell Stereocilia Morphology in Inner Ears of Deaf Whirler Mice.

    PubMed

    Chien, Wade W; Isgrig, Kevin; Roy, Soumen; Belyantseva, Inna A; Drummond, Meghan C; May, Lindsey A; Fitzgerald, Tracy S; Friedman, Thomas B; Cunningham, Lisa L

    2016-02-01

    Hereditary deafness is one of the most common disabilities affecting newborns. Many forms of hereditary deafness are caused by morphological defects of the stereocilia bundles on the apical surfaces of inner ear hair cells, which are responsible for sound detection. We explored the effectiveness of gene therapy in restoring the hair cell stereocilia architecture in the whirlin mouse model of human deafness, which is deaf due to dysmorphic, short stereocilia. Wild-type whirlin cDNA was delivered via adeno-associated virus (AAV8) by injection through the round window of the cochleas in neonatal whirler mice. Subsequently, whirlin expression was detected in infected hair cells (IHCs), and normal stereocilia length and bundle architecture were restored. Whirlin gene therapy also increased inner hair cell survival in the treated ears compared to the contralateral nontreated ears. These results indicate that a form of inherited deafness due to structural defects in cochlear hair cells is amenable to restoration through gene therapy.

  5. Keratin-containing inclusions affect cell morphology and distribution of cytosolic cellular components.

    PubMed

    Hanada, Shinichiro; Harada, Masaru; Kumemura, Hiroto; Omary, M Bishr; Kawaguchi, Takumi; Taniguchi, Eitaro; Koga, Hironori; Yoshida, Takafumi; Maeyama, Michiko; Baba, Shinji; Ueno, Takato; Sata, Michio

    2005-04-01

    Many neurodegenerative diseases are characterized by the presence of protein aggregates bundled with intermediate filaments (IFs) and similar structures, known as Mallory bodies (MBs), are observed in various liver diseases. IFs are anchored at desmosomes and hemidesmosomes, however, interactions with other intercellular junctions have not been determined. We investigated the effect of IF inclusions on junction-associated and cytosolic proteins in various cultured cells. We performed gene transfection of the green fluorescent protein (GFP)-tagged cytokeratin (CK) 18 mutant arg89cys (GFP-CK18 R89C) in cultured cells and observed CK aggregations as well as loss of IF networks. Among various junction-associated proteins, zonula occludens-1 and beta-catenin were colocalized with CK aggregates on immunofluorescent analyses. Similar results were obtained on immunostaining for cytosolic proteins, 14-3-3 zeta protein, glucose-6-phosphate dehydrogenase and DsRed. E-cadherin, a basolateral membrane protein in polarized epithelia, was present on both the apical and basolateral domains in GFP-CK18 R89C-transfected cells. Furthermore, cells containing CK aggregates were significantly larger than GFP-tagged wild type CK18 (GFP-WT CK18)-transfected or non-transfected cells (P < 0.01) and sometimes their morphology was significantly altered. Our data indicate that CK aggregates affect not only cell morphology but also the localization of various cytosolic components, which may affect the cellular function.

  6. Primary Esophageal Extranasal NK/T Cell Lymphoma With Biphasic Morphology

    PubMed Central

    Ye, Zi-Yin; Cao, Qing-Hua; Liu, Fang; Lu, Xiao-Fang; Li, Shu-Rong; Li, Chang-Zhao; Chen, Shao-Hong

    2015-01-01

    Abstract We report a case of esophageal extranasal NK/T cell lymphoma with biphasic morphologic features revealed by a deep large piecemeal biopsy. A 40-year-old man present with pharyngalgia, dysphagia, recurrent fever, and 5-kg weight loss for 8 months. Endoscopy demonstrated progressing longitudinal ulcers and mucosal bridges along the esophagus. The first and second biopsies obtained superficial mucosa with scattered bland-looking small lymphocytes. A subsequent large piecemeal snare abscission for biopsy showed atypical lymphoid cells infiltrating into the deep lamina propria and muscularis mucosae, whereas the superficial lamina propria was highly edematous with scant small lymphocytes. Immunohistochemical studies confirmed that both underlying atypical cells and superficial small lymphocytes were neoplastic, sharing an identical immunophenotype: positive for CD2, CD3, CD43, CD8, CD56, TIA-1 and granzyme B. Epstein-Barr virus–encoded small RNAs were found in both cells. The histologic findings were diagnostic of primary esophageal extranasal NK/T cell lymphoma. However, the patient developed bone marrow depression during chemotherapy and died of massive cerebral hemorrhage after the first cycle of chemotherapy. Primary esophageal extranodal NK/T cell lymphoma nasal type is extremely rare. We show the biphasic morphology of this disease, which highlights the importance of deep biopsy for accurate diagnosis. PMID:26181557

  7. Comparisons of cell culture medium using distribution of morphological features in microdevice.

    PubMed

    Sasaki, Hiroto; Enomoto, Junko; Ikeda, Yurika; Honda, Hiroyuki; Fukuda, Junji; Kato, Ryuji

    2016-01-01

    As the number of available cell types grows, it becomes necessary to develop more effective ways to optimize the cell-culture medium for each cell line and culture condition. However, because of the vast number of parameters that must be decided, such as the combination of components, optimization is both laborious and costly. Microdevices are a cost-effective way to perform such evaluations because they use only a small volume of media and enable high-throughput analyses. However, assays performed in microdevices are themselves minimized, and each assay unit (well/chamber) commonly contains an insufficient number of cells for comprehensive evaluations such as gene-expression or flow-cytometry analyses. To address this issue, we introduced image-based analysis in conjunction with microdevice assays; this approach allows quantification of every cell in each assay unit. To quantitatively profile differences in cellular behaviors in a microdevice under different culture media conditions, we developed a non-staining image-based analysis method that utilizes cellular morphology. Our approach combines the structural advantages of microdevices, which can increase the stability of images, and the quantitative advantages of an image-based cell evaluation technique that utilizes time-course population change in several morphological features. Our results demonstrate that cellular changes due to small alterations in the concentration of serum in medium or differences in the basal medium can be profiled using only microscopic images.

  8. Role of 4- tert -Butylpyridine as a Hole Transport Layer Morphological Controller in Perovskite Solar Cells

    SciTech Connect

    Wang, Shen; Sina, Mahsa; Parikh, Pritesh; Uekert, Taylor; Shahbazian, Brian; Devaraj, Arun; Meng, Ying Shirley

    2016-09-14

    Hybrid organic-inorganic materials for high efficiency, low cost photovoltaic devices have seen rapid progress since the introduction of lead based perovskites and solid-state hole transport layers. Although majority of the materials used for perovskite solar cells (PSC) are introduced from dye-sensitized solar cells (DSSCs), the presence of a perovskite capping layer as opposed to a single dye molecule (in DSSCs) changes the interactions between the various layers in perovskite solar cells. 4-tert-butylpyridine (tBP), commonly used in PSCs, is assumed to function as a charge recombination inhibitor, similar to DSSCs. However, the presence of a perovskite capping layer calls for a re-evaluation of its function in PSCs. Using TEM (transmission electron microscopy), we first confirm the role of tBP as a HTL morphology controller in PSCs. Our observations suggest that tBP significantly improves the uniformity of the HTL and avoids accumulation of Li salt. We also study degradation pathways by using FTIR (Fourier transform infrared spectroscopy) and APT (atom probe tomography) to investigate and visualize in 3-dimensions the moisture content associated with the Li salt. Long term effects, over 1000 hours, due to evaporation of tBP have also been studied. Based on our findings, a PSC failure mechanism associated with the morphological change of the HTL is proposed. tBP, the morphology controller in HTL, plays a key role in this process and thus this study highlights the need for additive materials with higher boiling points for consistent long term performance of PSCs.

  9. A direct evidence of morphological degradation on a nanometer scale in polymer solar cells.

    PubMed

    Schaffer, Christoph J; Palumbiny, Claudia M; Niedermeier, Martin A; Jendrzejewski, Christian; Santoro, Gonzalo; Roth, Stephan V; Müller-Buschbaum, Peter

    2013-12-10

    In situ measurement of a polymer solar cell using micro grazing incidence small angle X-ray scattering (μGISAXS) and current-voltage tracking is demonstrated. While measuring electric characteristics under illumination, morphological changes are probed by μGISAXS. The X-ray beam (green) impinges on the photo active layer with a shallow angle and scatters on a 2d detector. Degradation is explained by the ongoing nanomorphological changes observed.

  10. A simple method to adjust the morphology of gradient three-dimensional PTB7-Th:PC71BM polymer solar cells.

    PubMed

    Zhao, Ling; Zhao, Suling; Xu, Zheng; Yang, Qianqian; Huang, Di; Xu, Xurong

    2015-03-12

    Multiple interfaces are necessary for exciton separation in bulk heterojunction (BHJ) solar cells and continuous pathways for carrier transportation in donor : acceptor blend films, especially along the vertical direction, for efficient charge collection. Therefore film morphology is critically important to satisfy both in the construction of high performance organic solar cells (OSCs). In this work, the cooperative effect of solvent additives and solvent flux treatment on film morphology was confirmed. Furthermore, the correlation between a single processing parameter and the resulting morphology has been investigated. Our results show that film morphology can be tuned by changing the volume fraction of the solvent additive. Beyond that, after methanol fluxing, the OSC performance improves significantly, as short circuit current density (JSC) increases from 13.85 mA cm(-2) to 15.17 mA cm(-2) and fill factor (FF) from 62.9% to 65.7%, simultaneously. As a result, power conversion efficiency (PCE) increases from 6.79% to 7.67%. The favorable morphology was further investigated using time-of-flight secondary-ion mass spectroscopy (TOF-SIMS), and atomic force microscopy (AFM).

  11. Retinoic acid improves morphology of cultured peritoneal mesothelial cells from patients undergoing dialysis.

    PubMed

    Retana, Carmen; Sanchez, Elsa I; Gonzalez, Sirenia; Perez-Lopez, Alejandro; Cruz, Armando; Lagunas-Munoz, Jesus; Alfaro-Cruz, Carmen; Vital-Flores, Socorro; Reyes, José L

    2013-01-01

    Patients undergoing continuous ambulatory peritoneal dialysis are classified according to their peritoneal permeability as low transporter (low solute permeability) or High transporter (high solute permeability). Factors that determine the differences in permeability between them have not been fully disclosed. We investigated morphological features of cultured human peritoneal mesothelial cells from low or high transporter patients and its response to All trans retinoic Acid (ATRA, vitamin A active metabolite), as compared to non-uremic human peritoneal mesothelial cells. Control cells were isolated from human omentum. High or low transporter cells were obtained from dialysis effluents. Cells were cultured in media containing ATRA (0, 50, 100 or 200 nM). We studied length and distribution of microvilli and cilia (scanning electron microscopy), epithelial (cytokeratin, claudin-1, ZO-1 and occludin) and mesenchymal (vimentin and α-smooth muscle actin) transition markers by immunofluorescence and Western blot, and transforming growth factor β1 expression by Western blot. Low and high transporter exhibited hypertrophic cells, reduction in claudin-1, occludin and ZO-1 expression, cytokeratin and vimentin disorganization and positive α-smooth muscle actin label. Vimentin, α-smooth muscle actin and transforming growth factor-β1 were overexpressed in low transporter. Ciliated cells were diminished in low and high transporters. Microvilli number and length were severely reduced in high transporter. ATRA reduced hypertrophic cells number in low transporter. It also improved cytokeratin and vimentin organization, decreased vimentin and α-smooth muscle actin expression, and increased claudin 1, occludin and ZO-1 expression, in low and high transporter. In low transporter, ATRA reduced transforming growth factor-β1 expression. ATRA augmented percentage of ciliated cells in low and high transporter. It also augmented cilia length in high transporter. Alterations in

  12. Distribution and morphology of retinal ganglion cells in the Japanese quail.

    PubMed

    Ikushima, M; Watanabe, M; Ito, H

    1986-06-25

    A ganglion cell density map was produced from the Nissl-stained retinal whole mount of the Japanese quail. Ganglion cell density diminished nearly concentrically from the central area toward the retinal periphery. The mean soma area of ganglion cells in isodensity zones increased as the cell density decreased. The histograms of soma areas in each zone indicated that a population of small-sized ganglion cells persists into the peripheral retina. The total number of ganglion cells was estimated at about 2.0 million. Electron microscopic examination of the optic nerve revealed thin unmyelinated axons to comprise 69% of the total fiber count (about 2.0 million). Since there was no discrepancy between both the total numbers of neurons in the ganglion cell layer and optic nerve fibers, it is inferred that displaced amacrine cells are few, if any. The spectrum in optic nerve fiber diameter showed a unimodal skewed distribution quite similar to the histogram of soma areas of ganglion cells in the whole retina. This suggests a close correlation between soma areas and axon diameters. Retinal ganglion cells filled from the optic nerve with horseradish peroxidase were classified into 7 types according to such morphological characteristics as size, shape and location of the soma, as well as dendritic arborization pattern. Taking into account areal ranges of somata of each cell type, it can be assumed that most of the ganglion cells in the whole retinal ganglion cell layer are composed of type I, II and III cells, and that the population of uniformly small-sized ganglion cells corresponds to type I cells and is an origin of unmyelinated axons in the optic nerve.

  13. Morphology and chirality control self-assembly of sickle hemoglobin inside red blood cells

    NASA Astrophysics Data System (ADS)

    Li, Xuejin; Lei, Huan; Caswell, Bruce; Karniadakis, George

    2012-02-01

    Sickle cells exhibit abnormal morphology and membrane mechanics in the deoxygenated state due to the polymerization of the interior sickle hemoglobin (HbS). In this study, the dynamics of self-assembly behavior of HbS in solution and corresponding induced cell morphologies have been investigated by dissipative particle dynamics approach. A coarse-grained HbS model, which contains hydrophilic and hydrophobic particles, is constructed to match the structural properties and physical description (including crowding effects) of HbS. The hydrophobic interactions are shown to be necessary with chirality being the main driver for the formation of HbS fibers. In the absence of chain chirality, only the self-assembled small aggregates are observed whereas self-assembled elongated step-like bundle microstructures appear when we consider the chain chirality. Several typical cell morphologies (sickle, granular, elongated shapes), induced by the growth of HbS fibers, are revealed and their deviations from the biconcave shape are quantified by the asphericity and elliptical shape factors.

  14. Multifractal characterization of morphology of human red blood cells membrane skeleton.

    PubMed

    Ţălu, Ş; Stach, S; Kaczmarska, M; Fornal, M; Grodzicki, T; Pohorecki, W; Burda, K

    2016-04-01

    The purpose of this paper is to show applicability of multifractal analysis in investigations of the morphological changes of ultra-structures of red blood cells (RBCs) membrane skeleton measured using atomic force microscopy (AFM). Human RBCs obtained from healthy and hypertensive donors as well as healthy erythrocytes irradiated with neutrons (45 μGy) were studied. The membrane skeleton of the cells was imaged using AFM in a contact mode. Morphological characterization of the three-dimensional RBC surfaces was realized by a multifractal method. The nanometre scale study of human RBCs surface morphology revealed a multifractal geometry. The generalized dimensions Dq and the singularity spectrum f(α) provided quantitative values that characterize the local scale properties of their membrane skeleton organization. Surface characterization was made using areal ISO 25178-2: 2012 topography parameters in combination with AFM topography measurement. The surface structure of human RBCs is complex with hierarchical substructures resulting from the organization of the erythrocyte membrane skeleton. The analysed AFM images confirm a multifractal nature of the surface that could be useful in histology to quantify human RBC architectural changes associated with different disease states. In case of very precise measurements when the red cell surface is not wrinkled even very fine differences can be uncovered as was shown for the erythrocytes treated with a very low dose of ionizing radiation.

  15. Morphological changes among hippocampal dentate granule cells exposed to early kindling-epileptogenesis

    PubMed Central

    Singh, Shatrunjai P.; He, Xiaoping; McNamara, James O.; Danzer, Steve C.

    2013-01-01

    Temporal lobe epilepsy is associated with changes in the morphology of hippocampal dentate granule cells. These changes are evident in numerous models that are associated with substantial neuron loss and spontaneous recurrent seizures. By contrast, previous studies have shown that in the kindling model, it is possible to administer a limited number of stimulations sufficient to produce a lifelong enhanced sensitivity to stimulus evoked seizures without associated spontaneous seizures and minimal neuronal loss. Here we examined whether stimulation of the amygdala sufficient to evoke five convulsive seizures (class IV or greater on Racine’s scale) produce morphological changes similar to those observed in models of epilepsy associated with substantial cell loss. The morphology of GFP-expressing granule cells from Thy-1 GFP mice was examined either one day or one month after the last evoked seizure. Interestingly, significant reductions in dendritic spine density were evident one day after the last seizure, the magnitude of which had diminished by one month. Further, there was an increase in the thickness of the granule cell layer one day after the last evoked seizure, which was absent a month later. We also observed an increase in the area of the proximal axon, which again returned to control levels a month later. No differences in the number of basal dendrites were detected at either time point. These findings demonstrate that the early stages of kindling epileptogenesis produce transient changes in the granule cell body layer thickness, molecular layer spine density and axon proximal area, but do not produce striking rearrangements of granule cell structure. PMID:23893783

  16. Morphological Changes in CHO and VERO Cells Treated with T-2 Mycotoxin. Correlation with Inhibition of Protein Synthesis

    DTIC Science & Technology

    1984-08-21

    Changes in CHO and VERO Cells Treated with T-2 Mycotoxin . Correlation with Publication Inhibition of Protein Synthesis 6. PERFORMING ORG. REPORT...Chinese hamster ovary (CHO) and African green monkey kidney (VERO) cells to T-2 mycotoxin resulted in several morphological changes which appeared to be...Data Entered) . . . .. 0 Morphological Changes in CHO and VERO Cells Treated with T-2 • Mycotoxin . Correlation with Inhibition of Protein Synthesis

  17. The use of Electrolyte Additives to Improve the High Temperature Resilience of Li-Ion Cells

    NASA Technical Reports Server (NTRS)

    Smart, Marshall C.; Lucht, B. L.; Ratnakumar, Bugga V.

    2007-01-01

    This viewgraph presentation reviews the use of electrolyte additves to improve the resillience of Lithium ion cells. The objective of this work is to identify lithium-ion electrolytes, which will lead to Li-ion cells with a wide operational temperature range (+60 to -60 C), and to develop Li-ion electrolytes which result in cells that display improved high temperature resilience. Significant improvement in the high temperature resilience of Li-ion cells containing these additives was observed, with the most dramatic benefit being displayed by addition of DMAc. When the electrochemical properties of the individual electrodes were analyzed, the degradation of the anode kinetics was slowed most dramatically by the incorporation of DMAc into the electrolytes. Whereas, the greatest retention in the cathode kinetics was observed in the cell containing the electrolyte with VC added.

  18. Morphology and performances of the anodic oxide films on Ti6Al4V alloy formed in alkaline-silicate electrolyte with aminopropyl silane addition under low potential

    NASA Astrophysics Data System (ADS)

    Chen, Jiali; Wang, Jinwei; Yuan, Hongye

    2013-11-01

    Oxide films on Ti6Al4V alloy are prepared using sodium hydroxide-sodium silicate as the base electrolyte with addition of aminopropyl trimethoxysilane (APS) as additive by potentiostatic anodizing under 10 V. APS is incorporated into the films during anodizing and the surface morphology of the oxide films is changed from particle stacked to honeycomb-like porous surfaces as shown by scanning electron microscopy (SEM) with Energy Disperse Spectroscopy (EDX). The surface roughness and aminopropyl existence on the oxide films result in their differences in wettability as tested by the surface profile topography and contact angle measurements. The anti-abrasive ability of the anodic films is improved with the addition of APS due to its toughening effects and serving as lubricants in the ceramic oxide films as measured by ball-on-disk friction test. Also, potentiodynamic corrosion test proves that their anticorrosive ability in 3.5 wt.% NaCl is greatly improved as reflected by their much lower corrosion current (Icorr) and higher corrosion potential (Ecorr) than those of the substrate.

  19. From nano to micro: topographical scale and its impact on cell adhesion, morphology and contact guidance

    NASA Astrophysics Data System (ADS)

    Nguyen, Anh Tuan; Sathe, Sharvari R.; Yim, Evelyn K. F.

    2016-05-01

    Topography, among other physical factors such as substrate stiffness and extracellular forces, is known to have a great influence on cell behaviours. Optimization of topographical features, in particular topographical dimensions ranging from nanoscale to microscale, is the key strategy to obtain the best cellular performance for various applications in tissue engineering and regenerative medicine. In this review, we provide a comprehensive survey on the significance of sizes of topography and their impacts on cell adhesion, morphology and alignment, and neurite guidance. Also recent works mimicking the hierarchical structure of natural extracellular matrix by combining both nanoscale and microscale topographies are highlighted.

  20. Assessing epithelial cell nuclear morphology by using azimuthal light scattering spectroscopy

    NASA Astrophysics Data System (ADS)

    Yu, Chung-Chieh; Lau, Condon; Tunnell, James W.; Hunter, Martin; Kalashnikov, Maxim; Fang-Yen, Christopher; Fulghum, Stephen F.; Badizadegan, Kamran; Dasari, Ramachandra R.; Feld, Michael S.

    2006-11-01

    We describe azimuthal light scattering spectroscopy (ϕ/LSS), a novel technique for assessing epithelial-cell nuclear morphology. The difference between the spectra measured at azimuthal angles ϕ=0° and ϕ=90° preferentially isolates the single backscattering contribution due to large (˜10 μm) structures such as epithelial cell nuclei by discriminating against scattering from smaller organelles and diffusive background. We demonstrate the feasibility of using ϕ/LSS for cancer detection by showing that spectra from cancerous colon tissue exhibit significantly greater azimuthal asymmetry than spectra from normal colonic tissues.

  1. [In vitro modification of the morphology and the growth of cells infected with scrapie (author's transl)].

    PubMed

    Markovits, P; Dormont, D; Maunoury, R; Delamarche, C; Delpech, A; Dianoux, L; Latarjet, R

    1982-02-15

    Seven cell lines originated either in brains or in neuroblastomas of Mice, were infected with Scrapie. After 12 to 16 in vitro passages, 6 lines out of 7 showed changes of their morphology, and of their growth, resembling those occurring in the course of a malignant transformation. The Scrapie infected cells acquired the capacity to form 2 to 4 times more colonies in liquid medium than the controls, and to develop large tridimensional colonies in semisolid medium. The role of Scrapie in these changes is discussed.

  2. Identification and quantitation of morphological cell types in electrophoretically separated human embryonic kidney cell cultures

    NASA Technical Reports Server (NTRS)

    Williams, K. B.; Kunze, M. E.; Todd, P. W.

    1985-01-01

    Four major cell types were identified by phase microscopy in early passage human embryonic kidney cell cultures. They are small and large epithelioid, domed, and fenestrated cells. Fibroblasts are also present in some explants. The percent of each cell type changes with passage number as any given culture grows. As a general rule, the fraction of small epithelioid cells increases, while the fraction of fenestrated cells, always small, decreases further. When fibroblasts are present, they always increase in percentage of the total cell population. Electrophoretic separation of early passage cells showed that the domed cells have the highest electrophoretic mobility, fibroblasts have an intermediate high mobility, small epithelioid cells have a low mobility, broadly distributed, and fenestrated cells have the lowest mobility. All cell types were broadly distributed among electrophoretic subfractions, which were never pure but only enriched with respect to a given cell type.

  3. FoxP2 protein levels regulate cell morphology changes and migration patterns in the vertebrate developing telencephalon.

    PubMed

    Garcia-Calero, Elena; Botella-Lopez, Arancha; Bahamonde, Olga; Perez-Balaguer, Ariadna; Martinez, Salvador

    2016-07-01

    In the mammalian telencephalon, part of the progenitor cells transition from multipolar to bipolar morphology as they invade the mantle zone. This associates with changing patterns of radial migration. However, the molecules implicated in these morphology transitions are not well known. In the present work, we analyzed the function of FoxP2 protein in this process during telencephalic development in vertebrates. We analyzed the expression of FoxP2 protein and its relation with cell morphology and migratory patterns in mouse and chicken developing striatum. We observed FoxP2 protein expressed in a gradient from the subventricular zone to the mantle layer in mice embryos. In the FoxP2 low domain cells showed multipolar migration. In the striatal mantle layer where FoxP2 protein expression is higher, cells showed locomoting migration and bipolar morphology. In contrast, FoxP2 showed a high and homogenous expression pattern in chicken striatum, thus bipolar morphology predominated. Elevation of FoxP2 in the striatal subventricular zone by in utero electroporation promoted bipolar morphology and impaired multipolar radial migration. In mouse cerebral cortex we obtained similar results. FoxP2 promotes transition from multipolar to bipolar morphology by means of gradiental expression in mouse striatum and cortex. Together these results indicate a role of FoxP2 differential expression in cell morphology control of the vertebrate telencephalon.

  4. Following the biochemical and morphological changes of Bacillus atrophaeus cells during the sporulation process using Bioaerosol Mass Spectrometry.

    PubMed

    Tobias, Herbert J; Pitesky, Maurice E; Fergenson, David P; Steele, Paul T; Horn, Joanne; Frank, Matthias; Gard, Eric E

    2006-10-01

    Bioaerosol Mass Spectrometry (BAMS), a real-time single cell analytical technique, was used to follow the biochemical and morphological changes within a group of Bacillus atrophaeus cells by measuring individual cells during the process of sporulation. A mutant of B. atrophaeus that lacks the ability to produce dipicolinic acid (DPA) was also analyzed. Single cell aerodynamic sizing was used to follow gross morphological changes, and chemical analysis of single cells by mass spectrometry was used to follow some biochemical changes of B. atrophaeus cells during endospore formation.

  5. Morphological Variability and Distinct Protein Profiles of Cultured and Endosymbiotic Symbiodinium cells Isolated from Exaiptasia pulchella

    NASA Astrophysics Data System (ADS)

    Pasaribu, Buntora; Weng, Li-Chi; Lin, I.-Ping; Camargo, Eddie; Tzen, Jason T. C.; Tsai, Ching-Hsiu; Ho, Shin-Lon; Lin, Mong-Rong; Wang, Li-Hsueh; Chen, Chii-Shiarng; Jiang, Pei-Luen

    2015-10-01

    Symbiodinium is a dinoflagellate that plays an important role in the physiology of the symbiotic relationships of Cnidarians such as corals and sea anemones. However, it is very difficult to cultivate free-living dinoflagellates after being isolated from the host, as they are very sensitive to environmental changes. How these symbiont cells are supported by the host tissue is still unclear. This study investigated the characteristics of Symbiodinium cells, particularly with respect to the morphological variability and distinct protein profiles of both cultured and endosymbiotic Symbiodinium which were freshly isolated from Exaiptasia pulchella. The response of the cellular morphology of freshly isolated Symbiodinium cells kept under a 12 h L:12 h D cycle to different temperatures was measured. Cellular proliferation was investigated by measuring the growth pattern of Symbiodinium cells, the results of which indicated that the growth was significantly reduced in response to the extreme temperatures. Proteomic analysis of freshly isolated Symbiodinium cells revealed twelve novel proteins that putatively included transcription translation factors, photosystem proteins, and proteins associated with energy and lipid metabolism, as well as defense response. The results of this study will bring more understandings to the mechanisms governing the endosymbiotic relationship between the cnidarians and dinoflagellates.

  6. Phenomenology based multiscale models as tools to understand cell membrane and organelle morphologies

    PubMed Central

    Ramakrishnan, N.; Radhakrishnan, Ravi

    2016-01-01

    An intriguing question in cell biology is “how do cells regulate their shape?” It is commonly believed that the observed cellular morphologies are a result of the complex interaction among the lipid molecules (constituting the cell membrane), and with a number of other macromolecules, such as proteins. It is also believed that the common biophysical processes essential for the functioning of a cell also play an important role in cellular morphogenesis. At the cellular scale—where typical dimensions are in the order of micrometers—the effects arising from the molecular scale can either be modeled as equilibrium or non-equilibrium processes. In this chapter, we discuss the dynamically triangulated Monte Carlo technique to model and simulate membrane morphologies at the cellular scale, which in turn can be used to investigate several questions related to shape regulation in cells. In particular, we focus on two specific problems within the framework of isotropic and anisotropic elasticity theories: namely, (i) the origin of complex, physiologically relevant, membrane shapes due to the interaction of the membrane with curvature remodeling proteins, and (ii) the genesis of steady state cellular shapes due to the action of non-equilibrium forces that are generated by the fission and fusion of transport vesicles and by the binding and unbinding of proteins from the parent membrane. PMID:27087801

  7. Cystic Renal Oncocytoma and Tubulocystic Renal Cell Carcinoma: Morphologic and Immunohistochemical Comparative Study.

    PubMed

    Skenderi, Faruk; Ulamec, Monika; Vranic, Semir; Bilalovic, Nurija; Peckova, Kvetoslava; Rotterova, Pavla; Kokoskova, Bohuslava; Trpkov, Kiril; Vesela, Pavla; Hora, Milan; Kalusova, Kristyna; Sperga, Maris; Perez Montiel, Delia; Alvarado Cabrero, Isabel; Bulimbasic, Stela; Branzovsky, Jindrich; Michal, Michal; Hes, Ondrej

    2016-02-01

    Renal oncocytoma (RO) may present with a tubulocystic growth in 3% to 7% of cases, and in such cases its morphology may significantly overlap with tubulocystic renal cell carcinoma (TCRCC). We compared the morphologic and immunohistochemical characteristics of these tumors, aiming to clarify the differential diagnostic criteria, which facilitate the discrimination of RO from TCRCC. Twenty-four cystic ROs and 15 TCRCCs were selected and analyzed for: architectural growth patterns, stromal features, cytomorphology, ISUP nucleolar grade, necrosis, and mitotic activity. Immunohistochemical panel included various cytokeratins (AE1-AE3, OSCAR, CAM5.2, CK7), vimentin, CD10, CD117, AMACR, CA-IX, antimitochondrial antigen (MIA), EMA, and Ki-67. The presence of at least focal solid growth and islands of tumor cells interspersed with loose stroma, lower ISUP nucleolar grade, absence of necrosis, and absence of mitotic figures were strongly suggestive of a cystic RO. In contrast, the absence of solid and island growth patterns and presence of more compact, fibrous stroma, accompanied by higher ISUP nucleolar grade, focal necrosis, and mitotic figures were all associated with TCRCC. TCRCC marked more frequently for vimentin, CD10, AMACR, and CK7 and had a higher proliferative index by Ki-67 (>15%). CD117 was negative in 14/15 cases. One case was weakly CD117 reactive with cytoplasmic positivity. All cystic RO cases were strongly positive for CD117. The remaining markers (AE1-AE3, CAM5.2, OSCAR, CA-IX, MIA, EMA) were of limited utility. Presence of tumor cell islands and solid growth areas and the type of stroma may be major morphologic criteria in differentiating cystic RO from TCRCC. In difficult cases, or when a limited tissue precludes full morphologic assessment, immunohistochemical pattern of vimentin, CD10, CD117, AMACR, CK7, and Ki-67 could help in establishing the correct diagnosis.

  8. Early B cell factor 1 regulates adipocyte morphology and lipolysis in white adipose tissue.

    PubMed

    Gao, Hui; Mejhert, Niklas; Fretz, Jackie A; Arner, Erik; Lorente-Cebrián, Silvia; Ehrlund, Anna; Dahlman-Wright, Karin; Gong, Xiaowei; Strömblad, Staffan; Douagi, Iyadh; Laurencikiene, Jurga; Dahlman, Ingrid; Daub, Carsten O; Rydén, Mikael; Horowitz, Mark C; Arner, Peter

    2014-06-03

    White adipose tissue (WAT) morphology characterized by hypertrophy (i.e., fewer but larger adipocytes) associates with increased adipose inflammation, lipolysis, insulin resistance, and risk of diabetes. However, the causal relationships and the mechanisms controlling WAT morphology are unclear. Herein, we identified EBF1 as an adipocyte-expressed transcription factor with decreased expression/activity in WAT hypertrophy. In human adipocytes, the regulatory targets of EBF1 were enriched for genes controlling lipolysis and adipocyte morphology/differentiation, and in both humans and murine models, reduced EBF1 levels associated with increased lipolysis and adipose hypertrophy. Although EBF1 did not affect adipose inflammation, TNFα reduced EBF1 gene expression. High-fat diet intervention in Ebf1(+/-) mice resulted in more pronounced WAT hypertrophy and attenuated insulin sensitivity compared with wild-type littermate controls. We conclude that EBF1 is an important regulator of adipose morphology and fat cell lipolysis and may constitute a link between WAT inflammation, altered lipid metabolism, adipose hypertrophy, and insulin resistance.

  9. Early B-cell Factor 1 Regulates Adipocyte Morphology and Lipolysis in White Adipose Tissue

    PubMed Central

    Gao, Hui; Mejhert, Niklas; Fretz, Jackie A.; Arner, Erik; Lorente-Cebrián, Silvia; Ehrlund, Anna; Dahlman-Wright, Karin; Gong, Xiaowei; Strömblad, Staffan; Douagi, Iyadh; Laurencikiene, Jurga; Dahlman, Ingrid; Daub, Carsten O.; Rydén, Mikael; Horowitz, Mark C.; Arner, Peter

    2014-01-01

    Summary White adipose tissue (WAT) morphology characterized by hypertrophy (i.e. fewer but larger adipocytes) associates with increased adipose inflammation, lipolysis, insulin resistance and risk of diabetes. However, the causal relationships and the mechanisms controlling WAT morphology are unclear. Herein, we identified EBF1 as an adipocyte-expressed transcription factor with decreased expression/activity in WAT hypertrophy. In human adipocytes, the regulatory targets of EBF1 were enriched for genes controlling lipolysis and adipocyte morphology/differentiation and in both humans and murine models, reduced EBF1 levels associated with increased lipolysis and adipose hypertrophy. Although EBF1 did not affect adipose inflammation, TNFα reduced EBF1 gene expression. High fat diet-intervention in Ebf1+/− mice resulted in more pronounced WAT hypertrophy and attenuated insulin sensitivity compared with wild-type littermate controls. We conclude that EBF1 is an important regulator of adipose morphology and fat cell lipolysis and may constitute a link between WAT inflammation, altered lipid metabolism, adipose hypertrophy and insulin resistance. PMID:24856929

  10. Influence of graphite flake addition to sediment on electrogenesis in a sediment-type fuel cell.

    PubMed

    Lenin Babu, M; Venkata Mohan, S

    2012-04-01

    Graphite flakes at levels of 5%, 15%, 20% and 40% (weight per sediment volume) were added to lake bed sediment and electrogenesis in a sediment-type fuel cell was evaluated. Addition of graphite flakes by 20% to the sediment showed higher electrogenic activity of the fuel cell (578mV; 0.37mW) compared to control (304mV; 0.26mW). Further increment in the graphite loading showed a negative influence on the fuel cell behavior. A higher energy and capacitance were recorded with 20% addition of graphite flakes compared to the control. Increase in the exchange current density and decrease in the Tafel slope and electron transfer coefficient was observed with addition of graphite flakes. Apparent surface coverage analysis also supported the higher performance upon addition of 20% graphite flakes. The relative increase in the conductivity of bed due to addition of graphite flakes might be the reason for observed electrogenic activity. Marginal variation in the substrate utilization ( [Formula: see text] 50-55%) was observed with the addition of graphite flakes. By adding an optimum level of graphite flakes to sediment influences the fuel cell performance.

  11. Comparative study of electrolyte additives using electrochemical impedance spectroscopy on symmetric cells

    NASA Astrophysics Data System (ADS)

    Petibon, R.; Sinha, N. N.; Burns, J. C.; Aiken, C. P.; Ye, Hui; VanElzen, Collette M.; Jain, Gaurav; Trussler, S.; Dahn, J. R.

    2014-04-01

    The effect of various electrolyte additives and additive combinations added to a 1 M LiPF6 EC:EMC electrolyte on the positive and negative electrodes surface of 1 year old wound LiCoO2/graphite cells and Li[Ni0.4Mn0.4Co0.2])O2/graphite cells was studied using electrochemical impedance spectroscopy (EIS) on symmetric cells. The additives tested were: vinylene carbonate (VC), trimethoxyboroxine (TMOBX), fluoroethylene carbonate (FEC), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and H2O alone or in combination. In general, compared to control electrolyte, the additives tested reduced the impedance of the positive electrode and increased the impedance of the negative electrode with the exception of LiTFSI in Li[Ni0.4Mn0.4Co0.2]O2/graphite wound cells. Higher charge voltage led to higher positive electrode impedance, with the exception of 2%VC + 2% FEC, and 2% LiTFSI. In some cases, some additives when mixed with another controlled the formation of the SEI at one electrode, and shared the formation of the SEI at one electrode when mixed with a different additive.

  12. The Morphological and Molecular Changes of Brain Cells Exposed to Direct Current Electric Field Stimulation

    PubMed Central

    Pelletier, Simon J.; Lagacé, Marie; St-Amour, Isabelle; Arsenault, Dany; Cisbani, Giulia; Chabrat, Audrey; Fecteau, Shirley; Lévesque, Martin

    2015-01-01

    Background: The application of low-intensity direct current electric fields has been experimentally used in the clinic to treat a number of brain disorders, predominantly using transcranial direct current stimulation approaches. However, the cellular and molecular changes induced by such treatment remain largely unknown. Methods: Here, we tested various intensities of direct current electric fields (0, 25, 50, and 100V/m) in a well-controlled in vitro environment in order to investigate the responses of neurons, microglia, and astrocytes to this type of stimulation. This included morphological assessments of the cells, viability, as well as shape and fiber outgrowth relative to the orientation of the direct current electric field. We also undertook enzyme-linked immunosorbent assays and western immunoblotting to identify which molecular pathways were affected by direct current electric fields. Results: In response to direct current electric field, neurons developed an elongated cell body shape with neurite outgrowth that was associated with a significant increase in growth associated protein-43. Fetal midbrain dopaminergic explants grown in a collagen gel matrix also showed a reorientation of their neurites towards the cathode. BV2 microglial cells adopted distinct morphological changes with an increase in cyclooxygenase-2 expression, but these were dependent on whether they had already been activated with lipopolysaccharide. Finally, astrocytes displayed elongated cell bodies with cellular filopodia that were oriented perpendicularly to the direct current electric field. Conclusion: We show that cells of the central nervous system can respond to direct current electric fields both in terms of their morphological shape and molecular expression of certain proteins, and this in turn can help us to begin understand the mechanisms underlying the clinical benefits of direct current electric field. PMID:25522422

  13. Transcorneal electrical stimulation alters morphology and survival of retinal ganglion cells after optic nerve damage.

    PubMed

    Henrich-Noack, Petra; Voigt, Nadine; Prilloff, Sylvia; Fedorov, Anton; Sabel, Bernhard A

    2013-05-24

    Traumatic optic nerve injury leads to retrograde death of retinal ganglion cells (RGCs), but transcorneal electrical stimulation (TES) can increase the cell survival rate. To understand the mechanisms and to further define the TES-induced effects we monitored in living animals RGC morphology and survival after optic nerve crush (ONC) in real time by using in vivo confocal neuroimaging (ICON) of the retina. ONC was performed in rats and ICON was performed before crush and on post-lesion days 3, 7 and 15 which allowed us to repeatedly record RGC number and size. TES or sham-stimulation were performed immediately after the crush and on post-injury day 11. Three days after ONC we detected a higher percentage of surviving RGCs in the TES group as compared to sham-treated controls. However, the difference was below significance level on day 7 and disappeared completely by day 15. The death rate was more variable amongst the TES-treated rats than in the control group. Morphological analysis revealed that average cell size changed significantly in the control group but not in stimulated animals and the morphological alterations of surviving neurons were smaller in TES-treated compared to control cells. In conclusion, TES delays post-traumatic cell death significantly. Moreover, we found "responder animals" which also benefited in the long-term from the treatment. Our in vivo cellular imaging results provide evidence that TES reduces ONC-associated neuronal swelling and shrinkage especially in RGCs which survived long-term. Further studies are now needed to determine the differences of responders vs. non-responders.

  14. Black silicon SERS substrate: effect of surface morphology on SERS detection and application of single algal cell analysis.

    PubMed

    Deng, Yu-Luen; Juang, Yi-Je

    2014-03-15

    In this study, we have investigated the effect of the surface morphology of the black silicon substrate on surface enhanced Raman spectroscopy (SERS) and explored its application of single algal cell detection. By adjusting the O2 and SF6 flow rates in the cryogenic plasma etching process, different surface morphologies of the black silicon substrate was produced without performing the lithographic process. It was found the Raman signals were better enhanced as the tip density of the black silicon substrate increased. In addition, as the thickness of the deposited gold layer increased, the SERS effect increased as well, which could be owing to the generation of more hot spots by bridging individual silicon tips through deposition of gold layer. For the black silicon substrate with tip density of 30 tips/μm(2) and covered by 400 nm deposited gold layer, the detection limit of 10 fM R6G solution concentration with uniform SERS effect across the substrate was achieved. Furthermore, detection of individual algal cell (Chlorella vulgaris) was performed at the SERS substrate as fabricated and the Raman signals of carotenoid and lipid were substantially enhanced.

  15. 27 T ultra-high static magnetic field changes orientation and morphology of mitotic spindles in human cells

    PubMed Central

    Zhang, Lei; Hou, Yubin; Li, Zhiyuan; Ji, Xinmiao; Wang, Ze; Wang, Huizhen; Tian, Xiaofei; Yu, Fazhi; Yang, Zhenye; Pi, Li; Mitchison, Timothy J; Lu, Qingyou; Zhang, Xin

    2017-01-01

    Purified microtubules have been shown to align along the static magnetic field (SMF) in vitro because of their diamagnetic anisotropy. However, whether mitotic spindle in cells can be aligned by magnetic field has not been experimentally proved. In particular, the biological effects of SMF of above 20 T (Tesla) have never been reported. Here we found that in both CNE-2Z and RPE1 human cells spindle orients in 27 T SMF. The direction of spindle alignment depended on the extent to which chromosomes were aligned to form a planar metaphase plate. Our results show that the magnetic torque acts on both microtubules and chromosomes, and the preferred direction of spindle alignment relative to the field depends more on chromosome alignment than microtubules. In addition, spindle morphology was also perturbed by 27 T SMF. This is the first reported study that investigated the cellular responses to ultra-high magnetic field of above 20 T. Our study not only found that ultra-high magnetic field can change the orientation and morphology of mitotic spindles, but also provided a tool to probe the role of spindle orientation and perturbation in developmental and cancer biology. DOI: http://dx.doi.org/10.7554/eLife.22911.001 PMID:28244368

  16. Morphology-dependent light trapping in thin-film organic solar cells.

    PubMed

    Grote, Richard R; Brown, Steven J; Driscoll, Jeffrey B; Osgood, Richard M; Schuller, Jon A

    2013-09-09

    The active layer materials used in organic photovoltaic (OPV) cells often self-assemble into highly ordered morphologies, resulting in significant optical anisotropies. However, the impact of these anisotropies on light trapping in nanophotonic OPV architectures has not been considered. In this paper, we show that optical anisotropies in a canonical OPV material, P3HT, strongly affect absorption enhancements in ultra-thin textured OPV cells. In particular we show that plasmonic and gap-mode solar cell architectures redistribute electromagnetic energy into the out-of-plane field component, independent of the active layer orientation. Using analytical and numerical calculations, we demonstrate how the absorption in these solar cell designs can be significantly increased by reorienting polymer domains such that strongly absorbing axes align with the direction of maximum field enhancement.

  17. Zinc air refuelable battery: alternative zinc fuel morphologies and cell behavior

    SciTech Connect

    Cooper, J.F.; Krueger, R.

    1997-01-01

    Multicell zinc/air batteries have been tested previously in the laboratory and as part of the propulsion system of an electric bus; cut zinc wire was used as the anode material. This battery is refueled by a hydraulic transport of 0.5-1 mm zinc particles into hoppers above each cell. We report an investigation concerning alternative zinc fuel morphologies, and energy losses associated with refueling and with overnight or prolonged standby. Three types of fuel pellets were fabricated, tested and compared with results for cut wire: spheres produced in a fluidized bed electrolysis cell; elongated particles produced by gas-atomization; and pellets produced by chopping 1 mm porous plates made of compacted zinc fines. Relative sizes of the particles and cell gap dimensions are critical. All three types transported within the cell 1553 and showed acceptable discharge characteristics, but a fluidized bed approach appears especially attractive for owner/user recovery operations.

  18. Principles of connectivity among morphologically defined cell types in adult neocortex.

    PubMed

    Jiang, Xiaolong; Shen, Shan; Cadwell, Cathryn R; Berens, Philipp; Sinz, Fabian; Ecker, Alexander S; Patel, Saumil; Tolias, Andreas S

    2015-11-27

    Since the work of Ramón y Cajal in the late 19th and early 20th centuries, neuroscientists have speculated that a complete understanding of neuronal cell types and their connections is key to explaining complex brain functions. However, a complete census of the constituent cell types and their wiring diagram in mature neocortex remains elusive. By combining octuple whole-cell recordings with an optimized avidin-biotin-peroxidase staining technique, we carried out a morphological and electrophysiological census of neuronal types in layers 1, 2/3, and 5 of mature neocortex and mapped the connectivity between more than 11,000 pairs of identified neurons. We categorized 15 types of interneurons, and each exhibited a characteristic pattern of connectivity with other interneuron types and pyramidal cells. The essential connectivity structure of the neocortical microcircuit could be captured by only a few connectivity motifs.

  19. Morphologic and cytochemical characteristics of green turtle (Chelonia mydas) blood cells

    USGS Publications Warehouse

    Work, T.M.; Raskin, R.E.; Balazs, G.H.; Whittaker, S.D.

    1998-01-01

    Objective - To identify and characterize blood cells from free-ranging Hawaiian green turtles, Chelonia mydas. Sample Population - 26 green turtles from Puako on the island of Hawaii and Kaneohe Bay on the island of Oahu. Procedure - Blood was examined, using light and electron microscopy and cytochemical stains that included benzidine peroxidase, chloroacetate esterase, alpha naphthyl butyrate esterase, acid phosphatase, Sudan black B, periodic acid-Schiff, and toluidine blue. Results - 6 types of WBC were identified: lymphocytes, monocytes, thrombocytes, heterophils, basophils, and eosinophils (small and large). Morphologic characteristics of mononuclear cells and most granulocytes were similar to those of cells from other reptiles except that green turtles have both large and small eosinophils. Conclusions - Our classification of green turtle blood cells clarifies imporoper nomenclature reported previously and provides a reference for future hematologic studies in this species.

  20. Influence of basement membrane proteins and endothelial cell-derived factors on the morphology of human fetal-derived astrocytes in 2D.

    PubMed

    Levy, Amanda F; Zayats, Maya; Guerrero-Cazares, Hugo; Quiñones-Hinojosa, Alfredo; Searson, Peter C

    2014-01-01

    Astrocytes are the most prevalent type of glial cell in the brain, participating in a variety of diverse functions from regulating cerebral blood flow to controlling synapse formation. Astrocytes and astrocyte-conditioned media are widely used in models of the blood-brain barrier (BBB), however, very little is known about astrocyte culture in 2D. To test the hypothesis that surface coating and soluble factors influence astrocyte morphology in 2D, we quantitatively analyzed the morphology of human fetal derived astrocytes on glass, matrigel, fibronectin, collagen IV, and collagen I, and after the addition soluble factors including platelet-derived growth factor (PDGF), laminin, basic fibroblast growth factor (bFGF), and leukemia inhibitory factor (LIF). Matrigel surface coatings, as well as addition of leukemia inhibitory factor (LIF) to the media, were found to have the strongest effects on 2D astrocyte morphology, and may be important in improving existing BBB models. In addition, the novel set of quantitative parameters proposed in this paper provide a test for determining the influence of compounds on astrocyte morphology, both to screen for new endothelial cell-secreted factors that influence astrocytes, and to determine in a high-throughput way which factors are important for translation to more complex, 3D BBB models.

  1. Target morphology and cell memory: a model of regenerative pattern formation

    PubMed Central

    Bessonov, Nikolai; Levin, Michael; Morozova, Nadya; Reinberg, Natalia; Tosenberger, Alen; Volpert, Vitaly

    2015-01-01

    Despite the growing body of work on molecular components required for regenerative repair, we still lack a deep understanding of the ability of some animal species to regenerate their appropriate complex anatomical structure following damage. A key question is how regenerating systems know when to stop growth and remodeling – what mechanisms implement recognition of correct morphology that signals a stop condition? In this work, we review two conceptual models of pattern regeneration that implement a kind of pattern memory. In the first one, all cells communicate with each other and keep the value of the total signal received from the other cells. If a part of the pattern is amputated, the signal distribution changes. The difference fromthe original signal distribution stimulates cell proliferation and leads to pattern regeneration, in effect implementing an error minimization process that uses signaling memory to achieve pattern correction. In the second model, we consider a more complex pattern organization with different cell types. Each tissue contains a central (coordinator) cell that controls the tissue and communicates with the other central cells. Each of them keeps memory about the signals received from other central cells. The values of these signals depend on the mutual cell location, and the memory allows regeneration of the structure when it is modified. The purpose of these models is to suggest possible mechanisms of pattern regeneration operating on the basis of cell memory which are compatible with diverse molecular implementation mechanisms within specific organisms. PMID:26889161

  2. Morphologic maturation of tachykinin peptide-expressing cells in the postnatal rabbit retina.

    PubMed

    Casini, G; Trasarti, L; Andolfi, L; Bagnoli, P

    1997-04-18

    Tachykinin (TK) peptides, which include substance P, neurokinin A, two neurokinin A-related peptides and neurokinin B, are widely present in the nervous system, including the retina, where they act as neurotransmitters/modulators as well as growth factors. In the present study, we investigated the maturation of TK-immunoreactive (IR) cells in the rabbit retina with the aim of further contributing to the knowledge of the development of transmitter-identified retinal cell populations. In the adult retina, the pattern of TK immunostaining is consistent with the presence of TK peptides in amacrine, displaced amacrine, interplexiform and ganglion cells. In the newborn retina, intensely immunostained TK-IR somata are located in the ganglion cell layer (GCL) and in the inner nuclear layer (INL) adjacent to the inner plexiform layer (IPL). They are characterized by an oval-shaped cell body originating a single process without ramifications. TK-IR processes are occasionally observed in the IPL and in the outer plexiform layer (OPL). Long TK-IR fiber bundles are observed in the ganglion cell axon layer. TK-IR profiles resembling small somata are rarely observed in the INL adjacent to the OPL. At postnatal day (PND) 2, some TK-IR cells display more complex morphologic features, including processes with secondary ramifications. Long TK-IR processes in the IPL are often seen to terminate with growth cones. Between PND 6 and PND 11 (eye opening), there is a dramatic increase in the number of immunolabeled processes with growth cones both in the IPL and in the OPL and the mature lamination of TK-IR fibers in laminae 1, 3 and 5 of the IPL is established. TK-IR cells attain mature morphological characteristics and the rare, putative TK-IR somata in the distal INL are no longer observed. After eye opening, growth cones are not present and the pattern typical of the adult is reached. These observations indicate that the development of TK-IR cells can be divided into an early phase

  3. Morphological Characteristics of Electrophysiologically Characterized Layer Vb Pyramidal Cells in Rat Barrel Cortex

    PubMed Central

    Loucif, Alexandre J. C.; Schubert, Dirk; Möck, Martin

    2016-01-01

    Layer Vb pyramidal cells are the major output neurons of the neocortex and transmit the outcome of cortical columnar signal processing to distant target areas. At the same time they contribute to local tactile information processing by emitting recurrent axonal collaterals into the columnar microcircuitry. It is, however, not known how exactly the two types of pyramidal cells, called slender-tufted and thick-tufted, contribute to the local circuitry. Here, we investigated in the rat barrel cortex the detailed quantitative morphology of biocytin-filled layer Vb pyramidal cells in vitro, which were characterized for their intrinsic electrophysiology with special emphasis on their action potential firing pattern. Since we stained the same slices for cytochrome oxidase, we could also perform layer- and column-related analyses. Our results suggest that in layer Vb the unambiguous action potential firing patterns "regular spiking (RS)" and "repetitive burst spiking (RB)" (previously called intrinsically burst spiking) correlate well with a distinct morphology. RS pyramidal cells are somatodendritically of the slender-tufted type and possess numerous local intralaminar and intracolumnar axonal collaterals, mostly reaching layer I. By contrast, their transcolumnar projections are less well developed. The RB pyramidal cells are somatodendritically of the thick-tufted type and show only relatively sparse local axonal collaterals, which are preferentially emitted as long horizontal or oblique infragranular collaterals. However, contrary to many previous slice studies, a substantial number of these neurons also showed axonal collaterals reaching layer I. Thus, electrophysiologically defined pyramidal cells of layer Vb show an input and output pattern which suggests RS cells to be more "locally segregating" signal processors whereas RB cells seem to act more on a "global integrative" scale. PMID:27706253

  4. Determining the optimum morphology in high-performance polymer-fullerene organic photovoltaic cells

    PubMed Central

    Hedley, Gordon J.; Ward, Alexander J.; Alekseev, Alexander; Howells, Calvyn T.; Martins, Emiliano R.; Serrano, Luis A.; Cooke, Graeme; Ruseckas, Arvydas; Samuel, Ifor D. W.

    2013-01-01

    The morphology of bulk heterojunction organic photovoltaic cells controls many of the performance characteristics of devices. However, measuring this morphology is challenging because of the small length-scales and low contrast between organic materials. Here we use nanoscale photocurrent mapping, ultrafast fluorescence and exciton diffusion to observe the detailed morphology of a high-performance blend of PTB7:PC71BM. We show that optimized blends consist of elongated fullerene-rich and polymer-rich fibre-like domains, which are 10–50 nm wide and 200–400 nm long. These elongated domains provide a concentration gradient for directional charge diffusion that helps in the extraction of charge pairs with 80% efficiency. In contrast, blends with agglomerated fullerene domains show a much lower efficiency of charge extraction of ~45%, which is attributed to poor electron and hole transport. Our results show that the formation of narrow and elongated domains is desirable for efficient bulk heterojunction solar cells. PMID:24343223

  5. Stabilization of gene expression and cell morphology after explant recycling during fin explant culture in goldfish

    SciTech Connect

    Chenais, Nathalie; Lareyre, Jean-Jacques; Le Bail, Pierre-Yves; Labbe, Catherine

    2015-07-01

    The development of fin primary cell cultures for in vitro cellular and physiological studies is hampered by slow cell outgrowth, low proliferation rate, poor viability, and sparse cell characterization. Here, we investigated whether the recycling of fresh explants after a first conventional culture could improve physiological stability and sustainability of the culture. The recycled explants were able to give a supplementary cell culture showing faster outgrowth, cleaner cell layers and higher net cell production. The cells exhibited a highly stabilized profile for marker gene expression including a low cytokeratin 49 (epithelial marker) and a high collagen 1a1 (mesenchymal marker) expression. Added to the cell spindle-shaped morphology, motility behavior, and actin organization, this suggests that the cells bore stable mesenchymal characteristics. This contrast with the time-evolving expression pattern observed in the control fresh explants during the first 2 weeks of culture: a sharp decrease in cytokeratin 49 expression was concomitant with a gradual increase in col1a1. We surmise that such loss of epithelial features for the benefit of mesenchymal ones was triggered by an epithelial to mesenchymal transition (EMT) process or by way of a progressive population replacement process. Overall, our findings provide a comprehensive characterization of this new primary culture model bearing mesenchymal features and whose stability over culture time makes those cells good candidates for cell reprogramming prior to nuclear transfer, in a context of fish genome preservation. - Highlights: • Recycled fin explants outgrow cells bearing stable mesenchymal traits. • Cell production and quality is enhanced in the recycled explant culture system. • Fresh fin primary culture is highly variable and loose epithelial traits over time.

  6. Secreted or nonsecreted forms of acidic fibroblast growth factor produced by transfected epithelial cells influence cell morphology, motility, and invasive potential.

    PubMed Central

    Jouanneau, J; Gavrilovic, J; Caruelle, D; Jaye, M; Moens, G; Caruelle, J P; Thiery, J P

    1991-01-01

    Addition of exogenous acidic fibroblast growth factor (aFGF) to NBT-II epithelial carcinoma cells results in fibroblastic transformation and cell motility. We have generated aFGF-producing NBT-II cells by transfection with recombinant expression vectors containing human aFGF cDNA, or the human aFGF cDNA coupled to a signal peptide (SP) sequence. The effects of the nonsecreted and the secreted 16-kDa growth factor on the morphology, motility, and cell invasive potential (gelatinase activity) were compared. aFGF coupled to a SP was actively secreted out of the producing cells. The secretion of aFGF was not necessary for induction of gelatinase activity, as this was observed in NBT-II cells producing aFGF with or without SP. Production of aFGF, whether secreted or not secreted, resulted in increased in vitro motility of most isolated clones; however, there was no correlation between aFGF level and motility rate. The data suggest that expression of aFGF in NBT-II cells induces metastatic potential through an autocrine or intracrine mechanism. Images PMID:1707175

  7. [Additional phragmoplast corrects abnormal cytokinesis in wheat x rye hybrid pollen mother cells].

    PubMed

    Gordeeva, E I; Shamina, N V; Dudka, L F; Kovtunenko, V Ia; Bolobolova, E U

    2009-01-01

    The phragmoplast dysfunction in wheat x rye hybrid F1 male meiosis has been described. The pollen mother cells (PMCs) show the phenotype where transition from central spindle fibers (forming a solid bundle) to a phragmoplast (hollow cylinder) is blocked. The blockade suppresses centrifugal movement of the phragmoplast and cell plate formation. The resulting cells occur to be binucleate. Sometimes, the two nuclei join and form one restitution nucleus. PMCs of wheat x rye F1 hybrid N D-144gp 06r. F1 (T. aestivum c. 93-60 T 9 x S. cereale c. Saratovskaya 7) showing this phenotype have an additional phragmoplast at late telophase. This happens like that in the case of immobile phragmoplast formation in meiosis in bicotyledons: the new phragmoplast arises by the aid of microtubules polymerization starting from the spindle poles. The new additional phragmoplast builds a new cell plate and accomplishes cytokinesis.

  8. Morphology studies on high-temperature polymer electrolyte membrane fuel cell electrodes

    NASA Astrophysics Data System (ADS)

    Mack, Florian; Klages, Merle; Scholta, Joachim; Jörissen, Ludwig; Morawietz, Tobias; Hiesgen, Renate; Kramer, Dominik; Zeis, Roswitha

    2014-06-01

    The electrode morphology influences the properties and performance of polymer electrolyte membrane fuel cells (PEMFC). Here we report our studies of two different electrodes for high-temperature PEMFC prepared by spraying and coating and their impact on the fuel cell performance. Differences in 3D microstructure and adhesion between catalyst layer and gas diffusion layer (GDL) of the electrodes were studied with X-ray microtomography. Scanning electrode microscope investigations show hairline cracks between agglomerates on the surface of the sprayed electrode, whereas the coated electrode shows a network of shrinkage cracks in the catalyst layer. The distribution of the electrode binder polytetrafluoroethylene (PTFE) is related to the locally resolved conductivity, which was determined by scanning the electrode surfaces with a conductive atomic force microscopy (AFM) tip. The macrostructures of the sprayed and coated electrodes are different but contain similar pore structures. The coated electrode has a higher PTFE concentration on the top region, which tends to form a nonconductive and less wettable "skin" on the electrode surface and delays the start-up of the fuel cell. In contrast to low-temperature PEMFC, the electrode morphology has only a minor impact on the steady-state cell performance of high-temperature PEMFC.

  9. Estimation and extraction of B-cell linear epitopes predicted by mathematical morphology approaches.

    PubMed

    Chang, Hao-Teng; Liu, Chih-Hong; Pai, Tun-Wen

    2008-01-01

    B-cell epitope prediction facilitates the design and synthesis of short peptides for various immunological applications. Several algorithms have been developed to predict B-cell linear epitopes (LEs) from primary sequences of antigens, providing important information for immunobiological experiments and antibody design. This paper describes two robust methods, LE prediction with/without local peak extraction (LEP-LP and LEP-NLP), based on antigenicity scale and mathematical morphology for the prediction of B-cell LEs. Previous studies revealed that LEs could occur in regions with low-to-moderate but not globally high antigenicity scales. Hence, we developed a method adopting mathematical morphology to extract local peaks from a linear combination of the propensity scales of physico-chemical characteristics at each antigen residue. Comparison among LEP-LP/LEP-NLP, BepiPred and BEPITOPE revealed that our algorithms performed better in retrieving epitopes with low-to-moderate antigenicity and achieved comparable performance according to receiver operation characteristics (ROC) curve analysis. Of the identified LEs, over 30% were unable to be predicted by BepiPred and BEPITOPE employing an average threshold of antigenicity index or default settings. Our LEP-LP method provides a bioinformatics approach for predicting B-cell LEs with low- to-moderate antigenicity. The web-based server was established at http://biotools.cs.ntou.edu.tw/lepd_antigenicity. php for free use.

  10. Toward bulk heterojunction polymer solar cells with thermally stable active layer morphology

    NASA Astrophysics Data System (ADS)

    Cardinaletti, Ilaria; Kesters, Jurgen; Bertho, Sabine; Conings, Bert; Piersimoni, Fortunato; D'Haen, Jan; Lutsen, Laurence; Nesladek, Milos; Van Mele, Bruno; Van Assche, Guy; Vandewal, Koen; Salleo, Alberto; Vanderzande, Dirk; Maes, Wouter; Manca, Jean V.

    2014-01-01

    When state-of-the-art bulk heterojunction organic solar cells with ideal morphology are exposed to prolonged storage or operation at elevated temperatures, a thermally induced disruption of the active layer blend can occur, in the form of a separation of donor and acceptor domains, leading to diminished photovoltaic performance. Toward the long-term use of organic solar cells in real-life conditions, an important challenge is, therefore, the development of devices with a thermally stable active layer morphology. Several routes are being explored, ranging from the use of high glass transition temperature, cross-linkable and/or side-chain functionalized donor and acceptor materials, to light-induced dimerization of the fullerene acceptor. A better fundamental understanding of the nature and underlying mechanisms of the phase separation and stabilization effects has been obtained through a variety of analytical, thermal analysis, and electro-optical techniques. Accelerated aging systems have been used to study the degradation kinetics of bulk heterojunction solar cells in situ at various temperatures to obtain aging models predicting solar cell lifetime. The following contribution gives an overview of the current insights regarding the intrinsic thermally induced aging effects and the proposed solutions, illustrated by examples of our own research groups.

  11. The Influence of Genome and Cell Size on Brain Morphology in Amphibians.

    PubMed

    Roth, Gerhard; Walkowiak, Wolfgang

    2015-08-10

    In amphibians, nerve cell size is highly correlated with genome size, and increases in genome and cell size cause a retardation of the rate of development of nervous (as well as nonnervous) tissue leading to secondary simplification. This yields an inverse relationship between genome and cell size on the one hand and morphological complexity of the tectum mesencephali as the main visual center, the size of the torus semicircularis as the main auditory center, the size of the amphibian papilla as an important peripheral auditory structure, and the size of the cerebellum as a major sensorimotor center. Nervous structures developing later (e.g., torus and cerebellum) are more affected by secondary simplification than those that develop earlier (e.g., the tectum). This effect is more prominent in salamanders and caecilians than in frogs owing to larger genome and cells sizes in the former two taxa. We hypothesize that because of intragenomic evolutionary processes, important differences in brain morphology can arise independently of specific environmental selection.

  12. Dendritic Morphology of Caudal Periaqueductal Gray Projecting Retinal Ganglion Cells in Mongolian Gerbil (Meriones unguiculatus)

    PubMed Central

    Ren, Chaoran; Pu, Mingliang; Cui, Qi; So, Kwok-Fai

    2014-01-01

    In this study we investigated the morphological features of the caudal periaqueductal gray (cPAG)-projecting retinal ganglion cells (RGCs) in Mongolian gerbils using retrograde labeling, in vitro intracellular injection, confocal microscopy and three-dimensional reconstruction approaches. cPAG-projecting RGCs exhibit small somata (10–17 µm) and irregular dendritic fields (201–298 µm). Sizes of somata and dendritic fields do not show obvious variation at different distance from the optic disk (eccentricity). Dendrites are moderately branched. Morphological analysis (n = 23) reveals that cPAG-projecting RGCs ramified in sublamina a and b in the inner plexiform layer. These cells exhibit different stratification patterns based on the thickness of dendritic bands in sublaminas a and b: majority of analyzed cells (16 out of 23) have two bands of arborizations share similar thickness. The rest of analyzed cells (7 out of 23) exhibit thinner band in sublamina a than in sublamina b. Together, the present study suggests that cPAG of Mongolian gerbil could receive direct retinal inputs from two types of bistratified RGCs. Furthermore, a small subset of melanopsin-expressing RGCs (total 41 in 6 animals) is shown to innervate the rostral PAG (rPAG). Functional characteristics of these non-visual center projecting RGCs remain to be determined. PMID:25054882

  13. A&M. Hot cell addition (TAN633). Floor plan, elevations. Arrangement of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    A&M. Hot cell addition (TAN-633). Floor plan, elevations. Arrangement of monorail along corridor, four hot cells, plug access openings, viewing windows, photo darkroom. Ralph M. Parsons 1229-13-ANP/GE-3-633-A-1. Date: December 1956 as redrawn in August 1998. Approved by INEEL Classification Office for public release. INEEL index code no. 034-0633-00-693-107315 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  14. Dynamic changes in brewing yeast cells in culture revealed by statistical analyses of yeast morphological data.

    PubMed

    Ohnuki, Shinsuke; Enomoto, Kenichi; Yoshimoto, Hiroyuki; Ohya, Yoshikazu

    2014-03-01

    The vitality of brewing yeasts has been used to monitor their physiological state during fermentation. To investigate the fermentation process, we used the image processing software, CalMorph, which generates morphological data on yeast mother cells and bud shape, nuclear shape and location, and actin distribution. We found that 248 parameters changed significantly during fermentation. Successive use of principal component analysis (PCA) revealed several important features of yeast, providing insight into the dynamic changes in the yeast population. First, PCA indicated that much of the observed variability in the experiment was summarized in just two components: a change with a peak and a change over time. Second, PCA indicated the independent and important morphological features responsible for dynamic changes: budding ratio, nucleus position, neck position, and actin organization. Thus, the large amount of data provided by imaging analysis can be used to monitor the fermentation processes involved in beer and bioethanol production.

  15. Whole-cell patch-clamp recordings from morphologically- and neurochemically-identified hippocampal interneurons.

    PubMed

    Booker, Sam A; Song, Jie; Vida, Imre

    2014-09-30

    GABAergic inhibitory interneurons play a central role within neuronal circuits of the brain. Interneurons comprise a small subset of the neuronal population (10-20%), but show a high level of physiological, morphological, and neurochemical heterogeneity, reflecting their diverse functions. Therefore, investigation of interneurons provides important insights into the organization principles and function of neuronal circuits. This, however, requires an integrated physiological and neuroanatomical approach for the selection and identification of individual interneuron types. Whole-cell patch-clamp recording from acute brain slices of transgenic animals, expressing fluorescent proteins under the promoters of interneuron-specific markers, provides an efficient method to target and electrophysiologically characterize intrinsic and synaptic properties of specific interneuron types. Combined with intracellular dye labeling, this approach can be extended with post-hoc morphological and immunocytochemical analysis, enabling systematic identification of recorded neurons. These methods can be tailored to suit a broad range of scientific questions regarding functional properties of diverse types of cortical neurons.

  16. Morphological characterization of retinal bipolar cells in the marine teleost Rhinecanthus aculeatus.

    PubMed

    Pignatelli, Vincenzo; Marshall, Justin

    2010-08-01

    The marine teleost Rhinecanthus aculeatus (Balistidae) has recently been shown to possess trichromatic color vision supported by a retinal combination of double and single cones. Double cones are composed of two members with different spectral sensitivity. It is not known whether a correlation exists between the chromatic wiring of double cones to the inner retina and trichromacy, nor how unmixed, chromatic information is extracted from the two members of the couple. In mammalians, bipolar cells determine color segregation by means of the midget system, central to trichromatic color vision; however, midget bipolar cells have never been described in teleosts. On the basis of its likely importance in transferring chromatic photoreceptor signals to the inner retina, we have morphologically characterized the retinal bipolar cell types of R. aculeatus using DiOlistic staining techniques to verify if an anatomical specialization of this group of cells is required to support trichromatic color vision. Thirteen cell types are described: eight putative OFF types and five putative ON types. Of these, four had axonal boutons ramifying in both sublayers (ON and OFF) of the inner plexiform layer, six had terminals restricted to the OFF layer, and three cell types had terminals restricted to the ON layer. Dendritic arbors of bipolar cells had narrower diameters (5-40 microm) in comparison to bipolar cells of other teleost species; this supports the idea that a low degree of photoreceptor to bipolar convergence is correlated with trichromacy in this retina and possibly with the function of double cones as color receptors.

  17. Epithelial cell morphology and adhesion on diamond films deposited and chemically modified by plasma processes.

    PubMed

    Rezek, Bohuslav; Ukraintsev, Egor; Krátká, Marie; Taylor, Andrew; Fendrych, Frantisek; Mandys, Vaclav

    2014-09-01

    The authors show that nanocrystalline diamond (NCD) thin films prepared by microwave plasma enhanced chemical vapor deposition apparatus with a linear antenna delivery system are well compatible with epithelial cells (5637 human bladder carcinoma) and significantly improve the cell adhesion compared to reference glass substrates. This is attributed to better adhesion of adsorbed layers to diamond as observed by atomic force microscopy (AFM) beneath the cells. Moreover, the cell morphology can be adjusted by appropriate surface treatment of diamond by using hydrogen and oxygen plasma. Cell bodies, cytoplasmic rims, and filopodia were characterized by Peakforce AFM. Oxidized NCD films perform better than other substrates under all conditions (96% of cells adhered well). A thin adsorbed layer formed from culture medium and supplemented with fetal bovine serum (FBS) covered the diamond surface and played an important role in the cell adhesion. Nevertheless, 50-100 nm large aggregates formed from the RPMI medium without FBS facilitated cell adhesion also on hydrophobic hydrogenated NCD (increase from 23% to 61%). The authors discuss applicability for biomedical uses.

  18. Morphology and dynamic scaling analysis of cell colonies with linear growth fronts

    NASA Astrophysics Data System (ADS)

    Huergo, M. A. C.; Pasquale, M. A.; Bolzán, A. E.; Arvia, A. J.; González, P. H.

    2010-09-01

    The growth of linear cell colony fronts is investigated from the morphology of cell monolayer colonies, the cell size and shape distribution, the front displacement velocity, and the dynamic scaling analysis of front roughness fluctuations. At the early growth stages, colony patterns consist of rather ordered compact domains of small cells, whereas at advanced stages, an uneven distribution of cells sets in, and some large cells and cells exhibiting large filopodia are produced. Colony front profiles exhibit overhangs and behave as fractals with the dimension DF=1.25±0.05 . The colony fronts shift at 0.22±0.02μmmin-1 average constant linear velocity and their roughness (w) increases with time (t) . Dynamic scaling analysis of experimental and overhang-corrected growth profile data shows that w versus system width l log-log plots collapse to a single curve when l exceeds a certain threshold value lo , a width corresponding to the average diameter of few cells. Then, the influence of overhangs on the roughness dynamics becomes negligible, and a growth exponent β=0.33±0.02 is derived. From the structure factor analysis of overhang-corrected profiles, a global roughness exponent αs=0.50±0.05 is obtained. For l>200μm , this set of exponents fulfills the Family-Vicsek relationship. It is consistent with the predictions of the continuous Kardar-Parisi-Zhang model.

  19. Nanopattern-induced changes in morphology and motility of smooth muscle cells.

    PubMed

    Yim, Evelyn K F; Reano, Ron M; Pang, Stella W; Yee, Albert F; Chen, Christopher S; Leong, Kam W

    2005-09-01

    Cells are known to be surrounded by nanoscale topography in their natural extracellular environment. The cell behavior, including morphology, proliferation, and motility of bovine pulmonary artery smooth muscle cells (SMC) were studied on poly(methyl methacrylate) (PMMA) and poly(dimethylsiloxane) (PDMS) surfaces comprising nanopatterned gratings with 350 nm linewidth, 700 nm pitch, and 350 nm depth. More than 90% of the cells aligned to the gratings, and were significantly elongated compared to the SMC cultured on non-patterned surfaces. The nuclei were also elongated and aligned. Proliferation of the cells was significantly reduced on the nanopatterned surfaces. The polarization of microtubule organizing centers (MTOC), which are associated with cell migration, of SMC cultured on nanopatterned surfaces showed a preference towards the axis of cell alignment in an in vitro wound healing assay. In contrast, the MTOC of SMC on non-patterned surfaces preferentially polarized towards the wound edge. It is proposed that this nanoimprinting technology will provide a valuable platform for studies in cell-substrate interactions and for development of medical devices with nanoscale features.

  20. Solvent additive effects on small molecule crystallization in bulk heterojunction solar cells probed during spin casting.

    PubMed

    Perez, Louis A; Chou, Kang Wei; Love, John A; van der Poll, Thomas S; Smilgies, Detlef-M; Nguyen, Thuc-Quyen; Kramer, Edward J; Amassian, Aram; Bazan, Guillermo C

    2013-11-26

    Solvent additive processing can lead to drastic improvements in the power conversion efficiency (PCE) in solution processable small molecule (SPSM) bulk heterojunction solar cells. In situ grazing incidence wide-angle X-ray scattering is used to investigate the kinetics of crystallite formation during and shortly after spin casting. The additive is shown to have a complex effect on structural evolution invoking polymorphism and enhanced crystalline quality of the donor SPSM.

  1. Uv-Light Stabilization Additive Package For Solar Cell Module And Laminated Glass Applications

    DOEpatents

    Hanoka, Jack I.; Klemchuk, Peter P.

    2002-03-05

    An ultraviolet light stabilization additive package is used in an encapsulant material that may be used in solar cell modules, laminated glass and a variety of other applications. The ultraviolet light stabilization additive package comprises a first hindered amine light stabilizer and a second hindered amine light stabilizer. The first hindered amine light stabilizer provides thermal oxidative stabilization, and the second hindered amine light stabilizer providing photo-oxidative stabilization.

  2. Physiological and morphological characterization of ganglion cells in the salamander retina

    PubMed Central

    Wang, Jing; Jacoby, Roy; Wu, Samuel M.

    2016-01-01

    Retinal ganglion cells (RGCs) integrate visual information from the retina and transmit collective signals to the brain. A systematic investigation of functional and morphological characteristics of various types of RGCs is important to comprehensively understand how the visual system encodes and transmits information via various RGC pathways. This study evaluated both physiological and morphological properties of 67 RGCs in dark-adapted flat-mounted salamander retina by examining light-evoked cation and chloride current responses via voltage-clamp recordings and visualizing morphology by Lucifer yellow fluorescence with a confocal microscope. Six groups of RGCs were described: asymmetrical ON–OFF RGCs, symmetrical ON RGCs, OFF RGCs, and narrow-, medium- and wide-field ON–OFF RGCs. Dendritic field diameters of RGCs ranged 102–490 µm: narrow field (<200 µm, 31% of RGCs), medium field (200–300 µm, 45%) and wide field (>300 µm, 24%). Dendritic ramification patterns of RGCs agree with the sub-lamina A/B rule. 34% of RGCs were monostratified, 24% bistratified and 42% diffusely stratified. 70% of ON RGCs and OFF RGCs were monostratified. Wide-field RGCs were diffusely stratified. 82% of RGCs generated light-evoked ON–OFF responses, while 11% generated ON responses and 7% OFF responses. Response sensitivity analysis suggested that some RGCs obtained separated rod/cone bipolar cell inputs whereas others obtained mixed bipolar cell inputs. 25% of neurons in the RGC layer were displaced amacrine cells. Although more types may be defined by more refined classification criteria, this report is to incorporate more physiological properties into RGC classification. PMID:26731645

  3. Physiological and morphological characterization of ganglion cells in the salamander retina.

    PubMed

    Wang, Jing; Jacoby, Roy; Wu, Samuel M

    2016-02-01

    Retinal ganglion cells (RGCs) integrate visual information from the retina and transmit collective signals to the brain. A systematic investigation of functional and morphological characteristics of various types of RGCs is important to comprehensively understand how the visual system encodes and transmits information via various RGC pathways. This study evaluated both physiological and morphological properties of 67 RGCs in dark-adapted flat-mounted salamander retina by examining light-evoked cation and chloride current responses via voltage-clamp recordings and visualizing morphology by Lucifer yellow fluorescence with a confocal microscope. Six groups of RGCs were described: asymmetrical ON-OFF RGCs, symmetrical ON RGCs, OFF RGCs, and narrow-, medium- and wide-field ON-OFF RGCs. Dendritic field diameters of RGCs ranged 102-490 μm: narrow field (<200 μm, 31% of RGCs), medium field (200-300 μm, 45%) and wide field (>300 μm, 24%). Dendritic ramification patterns of RGCs agree with the sublamina A/B rule. 34% of RGCs were monostratified, 24% bistratified and 42% diffusely stratified. 70% of ON RGCs and OFF RGCs were monostratified. Wide-field RGCs were diffusely stratified. 82% of RGCs generated light-evoked ON-OFF responses, while 11% generated ON responses and 7% OFF responses. Response sensitivity analysis suggested that some RGCs obtained separated rod/cone bipolar cell inputs whereas others obtained mixed bipolar cell inputs. 25% of neurons in the RGC layer were displaced amacrine cells. Although more types may be defined by more refined classification criteria, this report is to incorporate more physiological properties into RGC classification.

  4. Morphology and Immunoreactivity of Retrogradely Double-Labeled Ganglion Cells in the Mouse Retina

    PubMed Central

    Wu, Samuel M.

    2011-01-01

    Purpose. To examine the specificity and reliability of a retrograde double-labeling technique that was recently established for identification of retinal ganglion cells (GCs) and to characterize the morphology of displaced (d)GCs (dGs). Methods. A mixture of the gap-junction–impermeable dye Lucifer yellow (LY) and the permeable dye neurobiotin (NB) was applied to the optic nerve stump for retrograde labeling of GCs and the cells coupled with them. A confocal microscope was adopted for morphologic observation. Results. GCs were identified by LY labeling, and they were all clearly labeled by NB. Cells coupled to GCs contained a weak NB signal but no LY. LY and NB revealed axon bundles, somas and dendrites of GCs. The retrogradely identified GCs numbered approximately 50,000 per retina, and they constituted 44% of the total neurons in the ganglion cell layer (GCL). Somas of retrogradely identified dGs were usually negative for glycine, ChAT (choline acetyltransferase), bNOS (brain-type nitric oxidase), GAD (glutamate decarboxylase), and glial markers, and occasionally, they were weakly GABA-positive. dGs averaged 760 per retina and composed 1.7% of total GCs. Sixteen morphologic subtypes of dGs were encountered, three of which were distinct from known GCs. dGs sent dendrites to either sublaminas of the IPL, mostly sublamina a. Conclusions. The retrograde labeling is reliable for identification of GCs. dGs participate in ON and OFF light pathways but favor the OFF pathway. ChAT, bNOS, glycine, and GAD remain reliable AC markers in the GCL. GCs may couple to GABAergic ACs, and the gap junctions likely pass NB and GABA. PMID:21482641

  5. ETM study of electroporation influence on cell morphology in human malignant melanoma and human primary gingival fibroblast cells

    PubMed Central

    Skolucka, Nina; Daczewska, Malgorzata; Saczko, Jolanta; Chwilkowska, Agnieszka; Choromanska, Anna; Kotulska, Malgorzata; Kaminska, Iwona; Kulbacka, Julita

    2011-01-01

    Objective To estimate electroporation (EP) influence on malignant and normal cells. Methods Two cell lines including human malignant melanoma (Me-45) and normal human gingival fibroblast (HGFs) were used. EP parameters were the following: 250, 1 000, 1 750, 2 500 V/cm; 50 µs by 5 impulses for every case. The viability of cells after EP was estimated by MTT assay. The ultrastructural analysis was observed by transmission electron microscope (Zeiss EM 900). Results In the current study we observed the intracellular effect following EP on Me-45 and HGF cells. At the conditions applied, we did not observe any significant damage of mitochondrial activity in both cell lines treated by EP. Conversely, we showed that EP in some conditions can stimulate cells to proliferation. Some changes induced by EP were only visible in electron microscopy. In fibroblast cells we observed significant changes in lower parameters of EP (250 and 1 000 V/cm). After applying higher electric field intensities (2 500 V/cm) we detected many vacuoles, myelin-like bodies and swallowed endoplasmic reticulum. In melanoma cells such strong pathological modifications after EP were not observed, in comparison with control cells. The ultrastructure of both treated cell lines was changed according to the applied parameters of EP. Conclusions We can claim that EP conditions are cell line dependent. In terms of the intracellular morphology, human fibroblasts are more sensitive to electric field as compared with melanoma cells. Optimal conditions should be determined for each cell line. Summarizing our study, we can conclude that EP is not an invasive method for human normal and malignant cells. This technique can be safely applied in chemotherapy for delivering drugs into tumor cells. PMID:23569735

  6. A Chemomechanical Model for Nuclear Morphology and Stresses during Cell Transendothelial Migration.

    PubMed

    Cao, Xuan; Moeendarbary, Emad; Isermann, Philipp; Davidson, Patricia M; Wang, Xiao; Chen, Michelle B; Burkart, Anya K; Lammerding, Jan; Kamm, Roger D; Shenoy, Vivek B

    2016-10-04

    It is now evident that the cell nucleus undergoes dramatic shape changes during important cellular processes such as cell transmigration through extracellular matrix and endothelium. Recent experimental data suggest that during cell transmigration the deformability of the nucleus could be a limiting factor, and the morphological and structural alterations that the nucleus encounters can perturb genomic organization that in turn influences cellular behavior. Despite its importance, a biophysical model that connects the experimentally observed nuclear morphological changes to the underlying biophysical factors during transmigration through small constrictions is still lacking. Here, we developed a universal chemomechanical model that describes nuclear strains and shapes and predicts thresholds for the rupture of the nuclear envelope and for nuclear plastic deformation during transmigration through small constrictions. The model includes actin contraction and cytosolic back pressure that squeeze the nucleus through constrictions and overcome the mechanical resistance from deformation of the nucleus and the constrictions. The nucleus is treated as an elastic shell encompassing a poroelastic material representing the nuclear envelope and inner nucleoplasm, respectively. Tuning the chemomechanical parameters of different components such as cell contractility and nuclear and matrix stiffnesses, our model predicts the lower bounds of constriction size for successful transmigration. Furthermore, treating the chromatin as a plastic material, our model faithfully reproduced the experimentally observed irreversible nuclear deformations after transmigration in lamin-A/C-deficient cells, whereas the wild-type cells show much less plastic deformation. Along with making testable predictions, which are in accord with our experiments and existing literature, our work provides a realistic framework to assess the biophysical modulators of nuclear deformation during cell transmigration.

  7. Effects of biaxial oscillatory shear stress on endothelial cell proliferation and morphology.

    PubMed

    Chakraborty, Amlan; Chakraborty, Sutirtha; Jala, Venkatakrishna R; Haribabu, Bodduluri; Sharp, M Keith; Berson, R Eric

    2012-03-01

    Wall shear stress (WSS) on anchored cells affects their responses, including cell proliferation and morphology. In this study, the effects of the directionality of pulsatile WSS on endothelial cell proliferation and morphology were investigated for cells grown in a Petri dish orbiting on a shaker platform. Time and location dependent WSS was determined by computational fluid dynamics (CFD). At low orbital speed (50 rpm), WSS was shown to be uniform (0-1 dyne/cm(2)) across the bottom of the dish, while at higher orbital speed (100 and 150 rpm), WSS remained fairly uniform near the center and fluctuated significantly (0-9 dyne/cm(2)) near the side walls of the dish. Since WSS on the bottom of the dish is two-dimensional, a new directional oscillatory shear index (DOSI) was developed to quantify the directionality of oscillating shear. DOSI approached zero for biaxial oscillatory shear of equal magnitudes near the center and approached one for uniaxial pulsatile shear near the wall, where large tangential WSS dominated a much smaller radial component. Near the center (low DOSI), more, smaller and less elongated cells grew, whereas larger cells with greater elongation were observed in the more uniaxial oscillatory shear (high DOSI) near the periphery of the dish. Further, cells aligned with the direction of the largest component of shear but were randomly oriented in low magnitude biaxial shear. Statistical analyses of the individual and interacting effects of multiple factors (DOSI, shear magnitudes and orbital speeds) showed that DOSI significantly affected all the responses, indicating that directionality is an important determinant of cellular responses.

  8. Evaluation of critical materials in five additional advance design photovoltaic cells

    SciTech Connect

    Smith, S.A.; Watts, R.L.; Martin, P.; Gurwell, W.E.

    1981-02-01

    The objective of this study is to identify potential material supply constraints due to the large-scale deployment of five advanced photovoltaic (PV) cell designs, and to suggest strategies to reduce the impacts of these production capacity limitations and potential future material shortages. The Critical Materials Assessment Program (CMAP) screens the designs and their supply chains and identifies potential shortages which might preclude large-scale use of the technologies. The results of the screening of five advanced PV cell designs are presented: (1) indium phosphide/cadmium sulfide, (2) zinc phosphide, (3) cadmium telluride/cadmium sulfide, (4) copper indium selenium, and (5) cadmium selenide photoelectrochemical. Each of these five cells is screened individually assuming that they first come online in 1991, and that 25 Gwe of peak capacity is online by the year 2000. A second computer screening assumes that each cell first comes online in 1991 and that each cell has a 5 GWe of peak capacity by the year 2000, so that the total online capacity for the five cells is 25 GWe. Based on a review of the preliminary baseline screening results, suggestions were made for varying such parameters as the layer thickness, cell production processes, etc. The resulting PV cell characterizations were then screened again by the CMAP computer code. The CMAP methodology used to identify critical materials is described; and detailed characterizations of the advanced photovoltaic cell designs under investigation, descriptions of additional cell production processes, and the results are presented. (WHK)

  9. Defining an additivity framework for mixture research in inducible whole-cell biosensors

    PubMed Central

    Martin-Betancor, K.; Ritz, C.; Fernández-Piñas, F.; Leganés, F.; Rodea-Palomares, I.

    2015-01-01

    A novel additivity framework for mixture effect modelling in the context of whole cell inducible biosensors has been mathematically developed and implemented in R. The proposed method is a multivariate extension of the effective dose (EDp) concept. Specifically, the extension accounts for differential maximal effects among analytes and response inhibition beyond the maximum permissive concentrations. This allows a multivariate extension of Loewe additivity, enabling direct application in a biphasic dose-response framework. The proposed additivity definition was validated, and its applicability illustrated by studying the response of the cyanobacterial biosensor Synechococcus elongatus PCC 7942 pBG2120 to binary mixtures of Zn, Cu, Cd, Ag, Co and Hg. The novel method allowed by the first time to model complete dose-response profiles of an inducible whole cell biosensor to mixtures. In addition, the approach also allowed identification and quantification of departures from additivity (interactions) among analytes. The biosensor was found to respond in a near additive way to heavy metal mixtures except when Hg, Co and Ag were present, in which case strong interactions occurred. The method is a useful contribution for the whole cell biosensors discipline and related areas allowing to perform appropriate assessment of mixture effects in non-monotonic dose-response frameworks PMID:26606975

  10. Ultrasound-microbubble mediated cavitation of plant cells: effects on morphology and viability.

    PubMed

    Qin, Peng; Xu, Lin; Zhong, Wenjing; Yu, Alfred C H

    2012-06-01

    The interaction between ultrasound pulses and microbubbles is known to generate acoustic cavitation that may puncture biological cells. This work presents new experimental findings on the bioeffects of ultrasound-microbubble mediated cavitation in plant cells with emphasis on direct observations of morphological impact and analysis of viability trends in tobacco BY-2 cells that are widely studied in higher plant physiology. The tobacco cell suspensions were exposed to 1 MHz ultrasound pulses in the presence of 1% v/v microbubbles (10% duty cycle; 1 kHz pulse repetition frequency; 70 mm between probe and cells; 1-min exposure time). Few bioeffects were observed at low peak negative pressures (<0.4 MPa) where stable cavitation presumably occurred. In contrast, at 0.9 MPa peak negative pressure (with more inertial cavitation activities according to our passive cavitation detection results), random pores were found on tobacco cell wall (observed via scanning electron microscopy) and enhanced exogenous uptake into the cytoplasm was evident (noted in our fluorescein isothiocyanate dextran uptake analysis). Also, instant lysis was observed in 23.4% of cells (found using trypan blue staining) and programmed cell death was seen in 23.3% of population after 12 h (determined by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling [TUNEL]). These bioeffects generally correspond in trend with those for mammalian cells. This raises the possibility of developing ultrasound-microbubble mediated cavitation into a targeted gene transfection paradigm for plant cells and, conversely, adopting plant cells as experimental test-beds for sonoporation-based gene therapy in mammalian cells.

  11. Dynamics and morphology characteristics of cell colonies with radially spreading growth fronts

    NASA Astrophysics Data System (ADS)

    Huergo, M. A. C.; Pasquale, M. A.; González, P. H.; Bolzán, A. E.; Arvia, A. J.

    2011-08-01

    The dynamics of two-dimensional (2D) radially spreading growth fronts of Vero cell colonies was investigated utilizing two types of colonies, namely type I starting from clusters with a small number of cells, which initially exhibited arbitrary-shaped rough growth fronts and progressively approached quasicircular ones as the cell population increased; and type II colonies, starting from a relatively large circular three-dimensional (3D) cell cluster. For large cell population colonies, the fractal dimension of the fronts was DF=1.20±0.05. For low cell populations, the mean colony radius increased exponentially with time, but for large ones the constant radial front velocity 0.20±0.02 μm min-1 was reached. Colony spreading was accompanied by changes in both cell morphology and average size, and by the formation of very large cells, some of them multinuclear. Therefore the heterogeneity of colonies increased and local driving forces that set in began to influence the 2D growth front kinetics. The retardation effect related to the exponential to constant radial front velocity transition was assigned to a number of possible interferences including the cell duplication and 3D growth in the bulk of the colony. The dynamic scaling analysis of overhang-corrected rough colony fronts, after arc-radius coordinate system transformation, resulted in roughness exponent α = 0.50±0.05 and growth exponent β = 0.32±0.04, for arc lengths greater than 100 μm. This set of scaling exponents agreed with that predicted by the Kardar, Parisi, and Zhang continuous equation. For arc lengths shorter than 2-3 cell diameters, the value α = 0.85±0.05 would be related to a cell front roughening caused by temporarily membrane deformations occasionally interfered by cell proliferation.

  12. A Fraction of CD133+ CNE2 Cells Is Made of Giant Cancer Cells with Morphological Evidence of Asymmetric Mitosis

    PubMed Central

    Jiang, Qingping; Zhang, Qianbing; Wang, Shuang; Xie, Siming; Fang, Weiyi; Liu, Zhen; Liu, Jinsong; Yao, Kaitai

    2015-01-01

    CD133 has been suggested as a broad-spectrum marker for cancer stem cells(CSCs). The present study investigated the expression of CD133 in biopsy tissues of nasopharyngeal carcinoma (NPC), NPC cell lines and the immortalized cell line NP69 by immunohistochemistry, flow cytometry and qRT-PCR. CD133+ cancer cells were isolated using magnetic-activated cell sorting technology. The study demonstrated that CD133+ cells are rare in NPC tissues and cell lines and that their self-renewal and proliferation abilities are stronger than those of CD133- cells and suggested that CD133+ NPC cells have characteristics of cancer stem cells. We further observed CD133+ cancer cells using a light microscope and scanning electron microscope. Generally, CD133+ cells are small, regular and round with small microvilli. On the other hand, CD133- cells are more polymorphic and larger with long micromicrovilli. Additionally, in some fields, several giant cancer cells (GCCs) in the CD133+ cell group were identified under the light microscope. Most of them were polynuclear cells. Under the scanning electron microscope, we found indefinite regular small bodies on the surface of or surrounding the giant cancer cells, some of which appeared to be creeping out the parental cells. This phenomenon was not observed in the CD133- cell groups. Through comparison with descriptions of apoptotic bodies in the literature and from the results of the acridine orange test, we propose that some of the small bodies are daughter cells of the GCCs. This phenomenon is a mode of division of cancer cells called neosis, or budding, which is a form of reproduction for simple organisms. Budding is satisfied with the rapid speed of tumor development. GCCs could be isolated by CD133 beads because the daughter cells have stem-cell characteristics and express stem-cell markers. PMID:26535065

  13. In vitro comet and micronucleus assays do not predict morphological transforming effects of silica particles in Syrian Hamster Embryo cells.

    PubMed

    Darne, Christian; Coulais, Catherine; Terzetti, Francine; Fontana, Caroline; Binet, Stéphane; Gaté, Laurent; Guichard, Yves

    2016-01-15

    Crystalline silica particles and asbestos have both been classified as carcinogenic by the International Agency for Research on Cancer (IARC). However, because of the limited data available, amorphous silica was not classifiable. In vitro, the carcinogenic potential of natural crystalline and amorphous silica particles has been revealed by the Syrian Hamster Embryo (SHE) cell transformation assay. On the other hand, the genotoxic potential of those substances has not been investigated in SHE cells. And yet, genotoxicity assays are commonly used for hazard evaluation and they are often used as in vitro assays of reference to predict a possible carcinogenic potential. The main objective of this study was to compare the genotoxic potential and the carcinogenic potential of different crystalline and amorphous silica particles in SHE cells. Three silica samples of different crystallinity were used: natural amorphous silica, partially crystallized silica and quartz silica particles. Their genotoxicity were tested through the in vitro micronucleus assay and the comet assay in SHE, and their carcinogenic potential through the SHE transformation assay. In addition, silica samples were also tested with the same genotoxicity assays in V79 hamster-lung cells, a common in vitro model for particle exposure. Results obtained in the micronucleus and the comet assays show that none of the silica was capable of inducing genotoxic effects in SHE cells and only the amorphous silica induced genotoxic effects in V79 cells. However in the SHE cell transformation assays, the partially crystallized and quartz silica were able to induce morphological cell transformation. Together, these data suggest that, in vitro, the short-term genotoxic assays alone are not sufficient to predict the hazard and the carcinogenic potential of this type of particles; SHE transformation assay appears a more reliable tool for this purpose and should be included in the "in vitro battery assays" for hazard

  14. Heterogeneity in mitochondrial morphology and membrane potential is independent of the nuclear division cycle in multinucleate fungal cells.

    PubMed

    Gerstenberger, John P; Occhipinti, Patricia; Gladfelter, Amy S

    2012-03-01

    In the multinucleate filamentous fungus Ashbya gossypii, nuclei divide asynchronously in a common cytoplasm. We hypothesize that the division cycle machinery has a limited zone of influence in the cytoplasm to promote nuclear autonomy. Mitochondria in cultured mammalian cells undergo cell cycle-specific changes in morphology and membrane potential and therefore can serve as a reporter of the cell cycle state of the cytoplasm. To evaluate if the cell cycle state of nuclei in A. gossypii can influence the adjacent cytoplasm, we tested whether local mitochondrial morphology and membrane potential in A. gossypii are associated with the division state of a nearby nucleus. We found that mitochondria exhibit substantial heterogeneity in both morphology and membrane potential within a single multinucleated cell. Notably, differences in mitochondrial morphology or potential are not associated with a specific nuclear division state. Heterokaryon mutants with a mixture of nuclei with deletions of and wild type for the mitochondrial fusion/fission genes DNM1 and FZO1 exhibit altered mitochondrial morphology and severe growth and sporulation defects. This dominant effect suggests that the gene products may be required locally near their expression site rather than diffusing widely in the cell. Our results demonstrate that mitochondrial dynamics are essential in these large syncytial cells, yet morphology and membrane potential are independent of nuclear cycle state.

  15. Enhanced performance of polymer:fullerene bulk heterojunction solar cells upon graphene addition

    SciTech Connect

    Robaeys, Pieter Dierckx, Wouter; Dexters, Wim; Spoltore, Donato; Drijkoningen, Jeroen; Bonaccorso, Francesco; Bourgeois, Emilie; D'Haen, Jan; Haenen, Ken; Manca, Jean V.; Nesladek, Milos; Liesenborgs, Jori; Van Reeth, Frank; Lombardo, Antonio; Ferrari, Andrea C.

    2014-08-25

    Graphene has potential for applications in solar cells. We show that the short circuit current density of P3HT (Poly(3-hexylthiophene-2,5-diyl):PCBM((6,6)-Phenyl C61 butyric acid methyl ester) solar cells is enhanced by 10% upon the addition of graphene, with a 15% increase in the photon to electric conversion efficiency. We discuss the performance enhancement by studying the crystallization of P3HT, as well as the electrical transport properties. We show that graphene improves the balance between electron and hole mobilities with respect to a standard P3HT:PCBM solar cell.

  16. Using wavelet denoising and mathematical morphology in the segmentation technique applied to blood cells images.

    PubMed

    Boix, Macarena; Cantó, Begoña

    2013-04-01

    Accurate image segmentation is used in medical diagnosis since this technique is a noninvasive pre-processing step for biomedical treatment. In this work we present an efficient segmentation method for medical image analysis. In particular, with this method blood cells can be segmented. For that, we combine the wavelet transform with morphological operations. Moreover, the wavelet thresholding technique is used to eliminate the noise and prepare the image for suitable segmentation. In wavelet denoising we determine the best wavelet that shows a segmentation with the largest area in the cell. We study different wavelet families and we conclude that the wavelet db1 is the best and it can serve for posterior works on blood pathologies. The proposed method generates goods results when it is applied on several images. Finally, the proposed algorithm made in MatLab environment is verified for a selected blood cells.

  17. Solvent polarity and nanoscale morphology in bulk heterojunction organic solar cells: A case study

    SciTech Connect

    Thomas, Ajith; Elsa Tom, Anju; Ison, V. V. E-mail: praveen@materials.iisc.ernet.in; Rao, Arun D.; Varman, K. Arul; Ranjith, K.; Ramamurthy, Praveen C. E-mail: praveen@materials.iisc.ernet.in; Vinayakan, R.

    2014-03-14

    Organic bulk heterojunction solar cells were fabricated under identical experimental conditions, except by varying the solvent polarity used for spin coating the active layer components and their performance was evaluated systematically. Results showed that presence of nitrobenzene-chlorobenzene composition governs the morphology of active layer formed, which is due to the tuning of solvent polarity as well as the resulting solubility of the P3HT:PCBM blend. Trace amount of nitrobenzene favoured the formation of better organised P3HT domains, as evident from conductive AFM, tapping mode AFM and surface, and cross-sectional SEM analysis. The higher interfacial surface area thus generated produced cells with high efficiency. But, an increase in the nitrobenzene composition leads to a decrease in cell performance, which is due to the formation of an active layer with larger size polymer domain networks with poor charge separation possibility.

  18. Metre-long cell-laden microfibres exhibit tissue morphologies and functions

    NASA Astrophysics Data System (ADS)

    Onoe, Hiroaki; Okitsu, Teru; Itou, Akane; Kato-Negishi, Midori; Gojo, Riho; Kiriya, Daisuke; Sato, Koji; Miura, Shigenori; Iwanaga, Shintaroh; Kuribayashi-Shigetomi, Kaori; Matsunaga, Yukiko T.; Shimoyama, Yuto; Takeuchi, Shoji

    2013-06-01

    Artificial reconstruction of fibre-shaped cellular constructs could greatly contribute to tissue assembly in vitro. Here we show that, by using a microfluidic device with double-coaxial laminar flow, metre-long core-shell hydrogel microfibres encapsulating ECM proteins and differentiated cells or somatic stem cells can be fabricated, and that the microfibres reconstitute intrinsic morphologies and functions of living tissues. We also show that these functional fibres can be assembled, by weaving and reeling, into macroscopic cellular structures with various spatial patterns. Moreover, fibres encapsulating primary pancreatic islet cells and transplanted through a microcatheter into the subrenal capsular space of diabetic mice normalized blood glucose concentrations for about two weeks. These microfibres may find use as templates for the reconstruction of fibre-shaped functional tissues that mimic muscle fibres, blood vessels or nerve networks in vivo.

  19. Improved morphology control using a modified two-step method for efficient perovskite solar cells.

    PubMed

    Bi, Dongqin; El-Zohry, Ahmed M; Hagfeldt, Anders; Boschloo, Gerrit

    2014-11-12

    A two-step wet chemical synthesis method for methylammonium lead(II) triiodide (CH3NH3PbI3) perovskite is further developed for the preparation of highly reproducible solar cells, with the following structure: fluorine-doped tin oxide (FTO)/TiO2 (compact)/TiO2 (mesoporous)/CH3NH3PbI3/spiro-OMeTAD/Ag. The morphology of the perovskite layer could be controlled by careful variation of the processing conditions. Specifically, by modifying the drying process and inclusion of a dichloromethane treatment, more uniform films could be prepared, with longer emission lifetime in the perovskite material and longer electron lifetime in solar cell devices, as well as faster electron transport and enhanced charge collection at the selective contacts. Solar cell efficiencies up to 13.5% were obtained.

  20. The cloning of growth associated protein 43 of Gekko japonicus and its effect on cell morphology.

    PubMed

    Feng, Xiao; Zhou, Youlang; Liu, Mei; Gu, Xingxing; Wang, Yongjun; Ding, Fei; Gu, Xiaosong; Liu, Yan

    2012-07-01

    The growth-associated protein 43 (GAP-43) gene of Gekko japonicus was obtained from a brain and spinal cord cDNA library. The results of northern blot analysis showed the gecko GAP-43 gene transcript is 1.7 kb in length, and it was abundantly expressed in tissues of brain, spinal cord and ovary. Gecko GAP-43 promoted the outgrowth of Gsn3 cells and PC12 cell in vitro, and phosphorylation at serine 42 modulated the effect of GAP-43 on cell spreading and morphology. The change in GAP-43 expression in the spinal cord after tail amputation was examined by reverse transcription polymerase chain reaction (RT-PCR). The level of GAP-43 in the spinal cord was increased during the time course we examined, indicating a possible correlation between GAP-43 expression and the spinal cord injury and regeneration.

  1. Dextran-based hydrogel formed by thiol-Michael addition reaction for 3D cell encapsulation.

    PubMed

    Liu, Zhen Qi; Wei, Zhao; Zhu, Xv Long; Huang, Guo You; Xu, Feng; Yang, Jian Hai; Osada, Yoshihito; Zrínyi, Miklós; Li, Jian Hui; Chen, Yong Mei

    2015-04-01

    Cell encapsulation in three-dimensional (3D) hydrogels can mimic native cell microenvironment and plays a major role in cell-based transplantation therapies. In this contribution, a novel in situ-forming hydrogel, Dex-l-DTT hydrogel ("l" means "linked-by"), by cross-linking glycidyl methacrylate derivatized dextran (Dex-GMA) and dithiothreitol (DTT) under physiological conditions, has been developed using thiol-Michael addition reaction. The mechanical properties, gelation process and degree of swelling of the hydrogel can be easily adjusted by changing the pH of phosphate buffer saline. The 3D cell encapsulation ability is demonstrated by encapsulating rat bone marrow mesenchymal stem cells (BMSCs) and NIH/3T3 fibroblasts into the in situ-forming hydrogel with maintained high viability. The BMSCs also maintain their differentiation potential after encapsulation. These results demonstrate that the Dex-l-DTT hydrogel holds great potential for biomedical field.

  2. Assessing the potential of colony morphology for dissecting the CFU-F population from human bone marrow stromal cells.

    PubMed

    Gothard, D; Dawson, J I; Oreffo, R O C

    2013-05-01

    Mesenchymal stem cells (MSCs) provide an ideal cell source for bone tissue engineering strategies. However, bone marrow stromal cell (BMSC) populations that contain MSCs are highly heterogeneous expressing a wide variety of proliferative and differentiation potentials. Current MSC isolation methods employing magnetic-activated and fluorescent-activated cell sorting can be expensive and time consuming and, in the absence of specific MSC markers, fail to generate homogeneous populations. We have investigated the potential of various colony morphology descriptors to provide correlations with cell growth potential. Density-independent colony forming unit-fibroblastic (CFU-F) capacity is a MSC prerequisite and resultant colonies display an array of shapes and sizes that might be representative of cell function. Parent colonies were initially categorised according to their diameter and cell density and grouped before passage for the subsequent assessment of progeny colonies. Whereas significant morphological differences between distinct parent populations indicated a correlation with immunophenotype, enhanced CFU-F capacity was not observed when individual colonies were isolated according to these morphological parameters. Colony circularity, an alternative morphological measure, displayed a strong correlation with subsequent cell growth potential. The current study indicates the potential of morphological descriptors for predicting cell growth rate and suggests new directions for research into dissection of human BMSC CFU-F populations.

  3. Subepithelial B cells in the human palatine tonsil. I. Morphologic, cytochemical and phenotypic characterization.

    PubMed

    Dono, M; Burgio, V L; Tacchetti, C; Favre, A; Augliera, A; Zupo, S; Taborelli, G; Chiorazzi, N; Grossi, C E; Ferrarini, M

    1996-09-01

    This study describes the purification of a subset of tonsillar B cells which share phenotypic, morphologic and cytochemical features with subepithelial (SE) B cells. These cells, which represented the 5-10% of the total tonsillar B cells, were found in the Percoll gradient fraction of highest density, together with resting follicular mantle (FM) B cells. The latter B cells, however, expressed surface CD5 and could be removed by an immune rosetting procedure. The remaining small CD5- B cells had a surface phenotype (IgM+, IgD+, CD23-, CD38+/-, CD10-, CD44+) that was different from that of FM (IgM+, IgD+, CD23+, CD39+, CD38-, CD10-, CD44+2) and of germinal center (GC) (CD23-, CD39-, CD38+, CD10+, CD44+/-, IgG+) B cells isolated from the same cell suspensions. Furthermore, the absence of surface activation markers (CD71 and CD69) and of surface IgG allowed us to distinguish small CD5- B cells from activated and memory cells migrating within Percoll fractions of lower density. In situ immunohistochemical studies revealed that B cells with an identical phenotype as that of small CD5- B cells could be detected predominantly in the SE region (lamina propria) of the tonsil, and also within the epithelium lining the cryptae. This area was also comprised of a relatively minor proportion of activated B cells, not found in the small CD5- B cell fraction owing to the separation procedure used. Consistent with the notion that the SE area could be a site of B cell activation was also the presence of activated macrophages and of plasma cells. Thirty to forty percent of small CD5- B cells isolated in suspension were positive for the endogeneous alkaline phosphatase (ALP) activity. In contrast, only a few FM B cells were ALP+, while GC cells were consistently ALP-. In situ studies also demonstrated a prevalent expression of ALP activity by the B cells in the SE area. At the ultrastructural level, small CD5- B cells were clearly different from both FM and GC B cells. They displayed a

  4. Effect of the additional anode layers on the absorption enhancement characteristic of plasmonic organic solar cells

    NASA Astrophysics Data System (ADS)

    Yoo, Sanghyuk; Kim, Jungho

    2014-12-01

    We numerically investigate the effect of additional anode layers on the absorption enhancement characteristic of pyramidal-grating plasmonic organic solar cells (OSCs) using the finite element method. The behaviors of the plasmonic absorption enhancement are compared between a “simple” structure consisting of only the active and metal cathode layers and a “practical” structure with the additional anode layers. The plasmonic absorption enhancement is identified by comparing the polarization-dependent absorbance spectra between the planar and plasmonic OSCs. When the active-layer thickness is small, the plasmonic resonance condition changes owing to the addition of the anode layers. When the active-layer thickness is large, the plasmonic resonance condition and corresponding absorption behavior show a slight difference irrespective of the inclusion of the additional anode layers. Therefore, the additional anode layers should be included in the optical analysis and design of plasmonic OSCs when the active-layer thickness is small.

  5. From Morphology to Interfaces to Tandem Geometries: Enhancing the Performance of Perovskite/Polymer Solar Cells

    NASA Astrophysics Data System (ADS)

    Russell, Thomas

    We have taken a new approach to develop mesoporous lead iodide scaffolds, using the nucleation and growth of lead iodide crystallites in a wet film. A simple time-dependent growth control enabled the manipulation of the mesoporous lead iodide layer quality in a continuous manner. The morphology of lead iodide is shown to influence the subsequent crystallization of methyamoniumleadiodide film by using angle-dependent grazing incidence x-ray scattering. The morphology of lead iodide film can be fine-tuned, and thus the methyamoniumleadiodide film quality can be effectively controlled, leading to an optimization of the perovskite active layer. Using this strategy, perovskite solar cells with inverted PHJ structure showed a PCE of 15.7 per cent with little hysteresis. Interface engineering is critical for achieving efficient solar cells, yet a comprehensive understanding of the interface between metal electrode and electron transport layer (ETL) is lacking. A significant power conversion efficiency (PCE) improvement of fullerene/perovskite planar heterojunction solar cells was achieved by inserting a fulleropyrrolidine interlayer between the silver electrode and electron transport layer. The interlayer was found to enhance recombination resistance, increases electron extraction rate and prolongs free carrier lifetime. We also uncovered a facile solution-based fabrication of high performance tandem perovskite/polymer solar cells where the front sub-cell consists of perovskite and the back sub-cell is a polymer-based layer. A record maximum PCE of 15.96 per cent was achieved, demonstrating the synergy between the perovskite and semiconducting polymers. This design balances the absorption of the perovskite and the polymer, eliminates the adverse impact of thermal annealing during perovskite fabrication, and affords devices with no hysteresis. This work was performed in collaboration with Y. Liu, Z. Page, D. Venkataraman and T. Emrick (UMASS), F. Liu (LBNL) and Q. Hu and R

  6. [Additive effect of marihuana and retrovirus in the anergy of natural killer cells in mice].

    PubMed

    Ongrádi, J; Specter, S; Horváth, A; Friedman, H

    1999-01-10

    Among the immunosuppressive effects of marijuana, impairment of natural killer cell activity is significant. HIV also inhibits these cells. Friend leukemia virus complex and its helper component Rowson-Parr virus induce early immunosuppression in mice resembling human AIDS, and late leukemia, providing a small animal AIDS model. Leukemia susceptible BALB/c and resistant C57BL/6 mice were infected with these viruses. At different time points, their natural killer cells separated from spleens were treated with 0 to 10 micrograms/ml tetrahydrocannabinol, subsequently mixed with Yac-1 target cells for 4 and 18 h. The natural killer cell activity in both mouse strains infected by either virus complex or helper virus weakened on days 2 to 4 postinfection, normalized by day 8 and enhanced on days 11 to 14. Natural killer cell activity upon the effect of low concentration (1.0 to 2.5 micrograms/ml) of tetrahydrocannabinol slightly increased in BALB/c, was unaffected in C57BL/6, especially in 18 h assays. In the combined effects of marijuana and retrovirus, damages by marijuana dominated over those of retroviruses. Inhibition or reactive enhancement of natural killer cell activity on the effect of viruses are similar to those of infected but marijuana-free counterparts, but on the level of uninfected cells treated with marijuana. The effects of marijuana and retrovirus are additive resulting in anergy of natural killer cells.

  7. Expression of VHL Causes Three-Dimensional Morphological Changes in Renal Cells Indicative of Proximal Tubule Differentiation

    PubMed Central

    Chiatar, Shivannah S; Eze, Ogechukwu P; Schoenfeld, Alan R

    2013-01-01

    Mutations in the von Hippel-Lindau (VHL) tumor suppressor gene are responsible for the VHL hereditary cancer syndrome, and are associated with the majority of clear cell renal cell carcinomas. In this study, scanning electron microscopy of VHL-negative renal carcinoma cells was utilized to examine the effects of VHL re-expression on the morphology of these cells. Significant differences were observed between the morphology of VHL-negative control cells and those with reintroduced VHL, with VHL expression mediating an apical surface that mounded upward, as opposed to the flat surfaces seen with VHL-negative cells. In long term cultures, rounded VHL-expressing cells grew in clusters on top the monolayer, and microvilli were observed on the apical face of these cells, in a manner suggestive of proximal tubule differentiation. In contrast, VHL-negative cells remained flat and did not develop microvilli in long-term cultures. Since VHL is a key member of an ubiquitin E3 ligase complex whose best known target is hypoxia-inducible factor alpha (HIF-α), we looked at the effects of HIF-α expression on cell morphology. Knockdown of HIF-2α in cells that only express this isoform had no effect on the morphology of the cells. These results indicate that VHL expression directs three dimensional morphological changes in renal cells indicative of differentiation, and while dysregulation of HIF-α may be necessary for tumorigenesis following VHL loss, it is not the major determinant of these VHL-mediated morphological changes. PMID:24308012

  8. Morphology of the Epidermis of the Neotropical Catfish Pimelodella lateristriga (Lichtenstein, 1823) with Emphasis in Club Cells

    PubMed Central

    Damasceno, Eduardo Medeiros; Monteiro, Juliana Castro; Duboc, Luiz Fernando; Dolder, Heidi; Mancini, Karina

    2012-01-01

    The epidermis of Ostariophysi fish is composed of 4 main cell types: epidermal cells (or filament containing cells), mucous cells, granular cells and club cells. The morphological analysis of the epidermis of the catfish Pimelodella lateristriga revealed the presence of only two types of cells: epidermal and club cells. The latter were evident in the middle layer of the epidermis, being the largest cells within the epithelium. Few organelles were located in the perinuclear region, while the rest of the cytoplasm was filled with a non-vesicular fibrillar substance. Club cells contained two irregular nuclei with evident nucleoli and high compacted peripheral chromatin. Histochemical analysis detected prevalence of protein within the cytoplasm other than carbohydrates, which were absent. These characteristics are similar to those described to most Ostariophysi studied so far. On the other hand, the epidermal cells differ from what is found in the literature. The present study described three distinct types, as follows: superficial, abundant and dense cells. Differences among them were restricted to their cytoplasm and nucleus morphology. Mucous cells were found in all Ostariophysi studied so far, although they were absent in P. lateristriga, along with granular cells, also typical of other catfish epidermis. The preset study corroborates the observations on club cells' morphology in Siluriformes specimens, and shows important differences in epidermis composition and cell structure of P. lateristriga regarding the literature data. PMID:23226253

  9. Methanol exposure interferes with morphological cell movements in the Drosophila embryo and causes increased apoptosis in the CNS.

    PubMed

    Mellerick, Dervla M; Liu, Heather

    2004-09-05

    Despite the significant contributions of tissue culture and bacterial models to toxicology, whole animal models for developmental neurotoxins are limited in availability and ease of experimentation. Because Drosophila is a well understood model for embryonic development that is highly accessible, we asked whether it could be used to study methanol developmental neurotoxicity. In the presence of 4% methanol, approximately 35% of embryos die and methanol exposure leads to severe CNS defects in about half those embryos, where the longitudinal connectives are dorsally displaced and commissure formation is severely reduced. In addition, a range of morphological defects in other germ layers is seen, and cell movement is adversely affected by methanol exposure. Although we did not find any evidence to suggest that methanol exposure affects the capacity of neuroblasts to divide or induces inappropriate apoptosis in these cells, in the CNS of germ band retracted embryos, the number of apoptotic nuclei is significantly increased in methanol-exposed embryos in comparison to controls, particularly in and adjacent to the ventral midline. Apoptosis contributes significantly to methanol neurotoxicity because embryos lacking the cell death genes grim, hid, and reaper have milder CNS defects resulting from methanol exposure than wild-type embryos. Our data suggest that when neurons and glia are severely adversely affected by methanol exposure, the damaged cells are cleared by apoptosis, leading to embryonic death. Thus, the Drosophila embryo may prove useful in identifying and unraveling mechanistic aspects of developmental neurotoxicity, specifically in relation to methanol toxicity.

  10. Improved performance of air-cathode microbial fuel cell through additional Tween 80

    NASA Astrophysics Data System (ADS)

    Wen, Qing; Kong, Fanying; Ma, Fang; Ren, Yueming; Pan, Zhongcheng

    The ability of electron transfer from microbe cell to anode electrode plays a key role in microbial fuel cell (MFC). This study explores a new approach to improve the MFC performance and electron transfer rate through addition of Tween 80. Results demonstrate that, for an air-cathode MFC operating on 1 g L -1 glucose, when the addition of Tween 80 increases from 0 to 80 mg L -1, the maximum power density increases from 21.5 to 187 W m -3 (0.6-5.2 W m -2), the corresponding current density increases from 1.8 to 17 A m -2, and the resistance of MFC decreases from 27.0 to 5.7 Ω. Electrochemical impedance spectroscopy (EIS) analysis suggests that the improvement of overall performance of the MFC can be attributed to the addition of Tween 80. The high power density achieved here may be due to the increase of permeability of cell membranes by addition of Tween 80, which reduces the electron transfer resistance through the cell membrane and increases the electron transfer rate and number, consequently enhances the current and power output. A promising way of utilizing surfactant to improve energy generation of MFC is demonstrated.

  11. Morphological Changes of Myoepithelial Cells in the Rat Submandibular Gland Following the Application of Surgical Stimuli

    PubMed Central

    Kawabe, Yoshihiro; Mizobe, Kenich; Bando, Yasuhiko; Sakiyama, Koji; Taira, Fuyoko; Tomomura, Akito; Araki, Hisao; Amano, Osamu

    2016-01-01

    Myoepithelial cells (MECs) exist on the basal surface of acini in major exocrine glands, include myofilaments and various constructive proteins, and share characteristics with smooth muscle and epithelial cells. MECs project several ramified processes to invest acini, and possibly contract to compress acini to support the secretion by the glandular cells. However, the functional roles of MECs in salivary secretion are still unclear. We investigated morphological changes in immunostained MECs using the anti-α-smooth muscle actin (αSMA) antibody in operated or non-operated contralateral (NC) submandibular glands after partial or total resection. Furthermore, we investigated and discuss other salivary glands of rats. MECs in the parotid, sublingual and submandibular gland of adult rats exhibited different shapes and localizations. After surgery, in both operated and NC glands, the number of MECs and αSMA-immunopositive areas increased significantly. Three-dimensional analysis using a confocal laser-scanning microscope revealed that substantial and significant enhancement became evident in the number, length, and thickness of MEC-processes covering acini of the operated and NC submandibular glands. The preset findings indicate that MECs alter the morphology of their processes in operated and NC glands after surgery of the partial or total resection. It is suggested that MECs promote salivary secretion using elongated, thickened, and more ramified processes. PMID:28127104

  12. Automated counting of morphologically normal red blood cells by using digital holographic microscopy and statistical methods

    NASA Astrophysics Data System (ADS)

    Moon, Inkyu; Yi, Faliu

    2015-09-01

    In this paper we overview a method to automatically count morphologically normal red blood cells (RBCs) by using off-axis digital holographic microscopy and statistical methods. Three kinds of RBC are used as training and testing data. All of the RBC phase images are obtained with digital holographic microscopy (DHM) that is robust to transparent or semitransparent biological cells. For the determination of morphologically normal RBCs, the RBC's phase images are first segmented with marker-controlled watershed transform algorithm. Multiple features are extracted from the segmented cells. Moreover, the statistical method of Hotelling's T-square test is conducted to show that the 3D features from 3D imaging method can improve the discrimination performance for counting of normal shapes of RBCs. Finally, the classifier is designed by using statistical Bayesian algorithm and the misclassification rates are measured with leave-one-out technique. Experimental results show the feasibility of the classification method for calculating the percentage of each typical normal RBC shape.

  13. Titanium dioxide nanoparticles inhibit proliferation and induce morphological changes and apoptosis in glial cells.

    PubMed

    Márquez-Ramírez, Sandra Gissela; Delgado-Buenrostro, Norma Laura; Chirino, Yolanda Irasema; Iglesias, Gisela Gutiérrez; López-Marure, Rebeca

    2012-12-16

    Titanium dioxide nanoparticles (TiO(2) NPs) are widely used in the chemical, electrical and electronic industries. TiO(2) NPs can enter directly into the brain through the olfactory bulb and be deposited in the hippocampus region. We determined the effect of TiO(2) NPs on rat and human glial cells, C6 and U373, respectively. We evaluated proliferation by crystal violet staining, internalization of TiO(2) NPs, and cellular morphology by TEM analysis, as well as F-actin distribution by immunostaining and cell death by detecting active caspase-3 and DNA fragmentation. TiO(2) NPs inhibited proliferation and induced morphological changes that were related with a decrease in immuno-location of F-actin fibers. TiO(2) NPs were internalized and formation of vesicles was observed. TiO(2) NPs induced apoptosis after 96h of treatment. Hence, TiO(2) NPs had a cytotoxic effect on glial cells, suggesting that exposure to TiO(2) NPs could cause brain injury and be hazardous to health.

  14. Ovine Mesenchymal Stromal Cells: Morphologic, Phenotypic and Functional Characterization for Osteochondral Tissue Engineering

    PubMed Central

    Sanjurjo-Rodríguez, Clara; Castro-Viñuelas, Rocío; Hermida-Gómez, Tamara; Fernández-Vázquez, Tania; Fuentes-Boquete, Isaac Manuel; de Toro-Santos, Francisco Javier; Blanco-García, Francisco Javier

    2017-01-01

    Introduction Knowledge of ovine mesenchymal stromal cells (oMSCs) is currently expanding. Tissue engineering combining scaffolding with oMSCs provides promising therapies for the treatment of osteochondral diseases. Purpose The aim was to isolate and characterize oMSCs from bone marrow aspirates (oBMSCs) and to assess their usefulness for osteochondral repair using β-tricalcium phosphate (bTCP) and type I collagen (Col I) scaffolds. Methods Cells isolated from ovine bone marrow were characterized morphologically, phenotypically, and functionally. oBMSCs were cultured with osteogenic medium on bTCP and Col I scaffolds. The resulting constructs were evaluated by histology, immunohistochemistry and electron microscopy studies. Furthermore, oBMSCs were cultured on Col I scaffolds to develop an in vitro cartilage repair model that was assessed using a modified International Cartilage Research Society (ICRS) II scale. Results oBMSCs presented morphology, surface marker pattern and multipotent capacities similar to those of human BMSCs. oBMSCs seeded on Col I gave rise to osteogenic neotissue. Assessment by the modified ICRS II scale revealed that fibrocartilage/hyaline cartilage was obtained in the in vitro repair model. Conclusions The isolated ovine cells were demonstrated to be oBMSCs. oBMSCs cultured on Col I sponges successfully synthesized osteochondral tissue. The data suggest that oBMSCs have potential for use in preclinical models prior to human clinical studies. PMID:28141815

  15. Titanium oxide morphology controls charge collection efficiency in quantum dot solar cells.

    PubMed

    Kolay, Ankita; Kumar, P Naresh; Kumar, Sarode Krishna; Deepa, Melepurath

    2017-02-08

    Charge transfer at the TiO2/quantum dots (QDs) interface, charge collection at the TiO2/QDs/current collector (FTO or SnO2:F) interface, and back electron transfer at the TiO2/QDs/S(2-) interface are processes controlled by the electron transport layer or TiO2. These key processes control the power conversion efficiencies (PCEs) of quantum dot solar cells (QDSCs). Here, four TiO2 morphologies, porous nanoparticles (PNPs), nanowires (NWs), nanosheets (NSHs) and nanoparticles (NPs), were sensitized with CdS and the photovoltaic performances were compared. The marked differences in the cell parameters on going from one morphology to the other have been explained by correlating the shape, structure and the above-described interfacial properties of a given TiO2 morphology to the said parameters. The average magnitudes of PCEs follow the order: NWs (5.96%) > NPs (4.95%) > PNPs (4.85%) > NSHs (2.5%), with the champion cell based on NWs exhibiting a PCE of 6.29%. For NWs, an optimal balance between the fast photo-excited electron injection to NWs at the NW/CdS interface, the high resistance offered at the TiO2 NW/CdS/S(2-) interfaces to electron recombination with the oxidized electrolyte or with the holes in CdS, the low electron transport resistance in NWs, and low dark currents, yields the highest efficiency due to directional unhindered transport of electrons afforded by the NWs. For NSHs, electron trapping in the two dimensional sheets, and a high electron recombination rate prevent the effective transfer of electrons to FTO, thus reducing short circuit current density significantly, resulting in a poor performance. This study provides a deep understanding of charge transfer, transport and collection processes necessary for the design of efficient QDSCs.

  16. Fractal morphology of Beta vulgaris L. cell suspension culture permeabilized with Triton X-100®

    NASA Astrophysics Data System (ADS)

    Arenas-Ocampo, M.; Alamilla-Beltrán, L.; Vanegas-Espinoza, P.; Camacho-Díaz, B.; Campos-Mendiola, R.; Gutiérrez-López, G.; Jiménez-Aparicio, A.

    2012-02-01

    In this work, morphology of Beta vulgaris L. cells permeabilized with 0.7mM of Triton X-100® was evaluated using digital image processing and concepts of fractal dimension (perimeter- area relations). Important morphometric changes were found when the contact-time with chemical agent was increased. The size of cells decreased, the cells lost the roundness and their shape was more sinuous; this behaviour was a result of a probable shrinkage caused by the excess of exposure with the permeabilization agent. Morphology of B. vulgaris cells after permeabilization, exhibited a fractal nature since the slope of the ratio of the logarithm of the perimeter vs logarithm of the area was higher than unit. Fractal geometry of the cell morphology was affected as a result of the exposure to Triton X-100®. Those changes can be attributed to the loss of turgor and structure of the cell wall.

  17. Morphology and ultrastructure of Interfilum and Klebsormidium (Klebsormidiales, Streptophyta) with special reference to cell division and thallus formation

    PubMed Central

    Mikhailyuk, Tatiana; Holzinger, Andreas; Massalski, Andrzej; Karsten, Ulf

    2014-01-01

    Representatives of the closely related genera, Interfilum and Klebsormidium, are characterized by unicells, dyads or packets in Interfilum and contrasting uniseriate filaments in Klebsormidium. According to the literature, these distinct thallus forms originate by different types of cell division, sporulation (cytogony) versus vegetative cell division (cytotomy), but investigations of their morphology and ultrastructure show a high degree of similarity. Cell walls of both genera are characterized by triangular spaces between cell walls of neighbouring cells and the parental wall or central space among the walls of a cell packet, exfoliations and projections of the parental wall and cap-like and H-like fragments of the cell wall. In both genera, each cell has its individual cell wall and it also has part of the common parental wall or its remnants. Therefore, vegetative cells of Interfilum and Klebsormidium probably divide by the same type of cell division (sporulation-like). Various strains representing different species of the two genera are characterized by differences in cell wall ultrastructure, particularly the level of preservation, rupture or gelatinization of the parental wall surrounding the daughter cells. The differing morphologies of representatives of various lineages result from features of the parental wall during cell separation and detachment. Cell division in three planes (usual in Interfilum and a rare event in Klebsormidium) takes place in spherical or short cylindrical cells, with the chloroplast positioned perpendicularly or obliquely to the filament (dyad) axis. The morphological differences are mainly a consequence of differing fates of the parental wall after cell division and detachment. The development of different morphologies within the two genera mostly depends on characters such as the shape of cells, texture of cell walls, mechanical interactions between cells and the influence of environmental conditions. PMID:26504365

  18. Solid polymer electrolyte electrochemical storage cell containing a redox shuttle additive for overcharge protection

    DOEpatents

    Richardson, Thomas J.; Ross, Philip N.

    1999-01-01

    A class of organic redox shuttle additives is described, preferably comprising nitrogen-containing aromatics compounds, which can be used in a high temperature (85.degree. C. or higher) electrochemical storage cell comprising a positive electrode, a negative electrode, and a solid polymer electrolyte to provide overcharge protection to the cell. The organic redox additives or shuttles are characterized by a high diffusion coefficient of at least 2.1.times.10.sup.-8 cm.sup.2 /second and a high onset potential of 2.5 volts or higher. Examples of such organic redox shuttle additives include an alkali metal salt of 1,2,4-triazole, an alkali metal salt of imidazole, 2,3,5,6-tetramethylpyrazine, 1,3,5-tricyanobenzene, and a dialkali metal salt of 3-4-dihydroxy-3-cyclobutene-1,2-dione.

  19. Quantification of cell, actin, and nuclear DNA morphology with high-throughput microscopy and CalMorph.

    PubMed

    Okada, Hiroki; Ohnuki, Shinsuke; Ohya, Yoshikazu

    2015-04-01

    Automated image acquisition and processing systems have been developed to quantitatively describe yeast cell morphology. These systems are superior to the preceding qualitative methods in terms of reproducibility, as they completely avoid subjective recognition of images. Because high-throughput microscopy has enabled rapid production of numerous cellular images, reinforcement of high-performance and high-throughput automated image-processing techniques has been in increasing demand in the field of biology. This protocol describes how to use a high-throughput microscope in conjunction with the image-processing software CalMorph, which outputs more than 500 morphological parameters, for quantification of cell, actin, and nuclear DNA morphology.

  20. Effects of Low PBP2b Levels on Cell Morphology and Peptidoglycan Composition in Streptococcus pneumoniae R6

    PubMed Central

    Berg, Kari Helene; Stamsås, Gro Anita; Straume, Daniel

    2013-01-01

    Streptococcus pneumoniae produces two class B penicillin-binding proteins, PBP2x and PBP2b, both of which are essential. It is generally assumed that PBP2x is specifically involved in septum formation, while PBP2b is dedicated to peripheral cell wall synthesis. However, little experimental evidence exists to substantiate this belief. In the present study, we obtained evidence that strongly supports the view that PBP2b is essential for peripheral peptidoglycan synthesis. Depletion of PBP2b expression gave rise to long chains of cells in which individual cells were compressed in the direction of the long axis and looked lentil shaped. This morphological change is consistent with a role for pneumococcal PBP2b in the synthesis of the lateral cell wall. Depletion of PBP2x, on the other hand, resulted in lemon-shaped and some elongated cells with a thickened midcell region. Low PBP2b levels gave rise to changes in the peptidoglycan layer that made pneumococci sensitive to exogenously added LytA during logarithmic growth and refractory to chain dispersion upon addition of LytB. Interestingly, analysis of the cell wall composition of PBP2b-depleted pneumococci revealed that they had a larger proportion of branched stem peptides in their peptidoglycan than the corresponding undepleted cells. Furthermore, MurM-deficient mutants, i.e., mutants lacking the ability to synthesize branched muropeptides, were found to require much higher levels of PBP2b to sustain growth than those required by MurM-proficient strains. These findings might help to explain why increased incorporation of branched muropeptides is required for high-level beta-lactam resistance in S. pneumoniae. PMID:23873916

  1. Morphological and proteomic analysis of early stage of osteoblast differentiation in osteoblastic progenitor cells

    SciTech Connect

    Hong, Dun; Chen, Hai-Xiao; Yu, Hai-Qiang; Liang, Yong; Wang, Carrie; Lian, Qing-Quan; Deng, Hai-Teng; Ge, Ren-Shan

    2010-08-15

    Bone remodeling relies on a dynamic balance between bone formation and resorption, mediated by osteoblasts and osteoclasts, respectively. Under certain stimuli, osteoprogenitor cells may differentiate into premature osteoblasts and further into mature osteoblasts. This process is marked by increased alkaline phosphatase (ALP) activity and mineralized nodule formation. In this study, we induced osteoblast differentiation in mouse osteoprogenitor MC3T3-E1 cells and divided the process into three stages. In the first stage (day 3), the MC3T3-E1 cell under osteoblast differentiation did not express ALP or deposit a mineralized nodule. In the second stage, the MC3T3-E1 cell expressed ALP but did not form a mineralized nodule. In the third stage, the MC3T3-E1 cell had ALP activity and formed mineralized nodules. In the present study, we focused on morphological and proteomic changes of MC3T3-E1 cells in the early stage of osteoblast differentiation - a period when premature osteoblasts transform into mature osteoblasts. We found that mean cell area and mean stress fiber density were increased in this stage due to enhanced cell spreading and decreased cell proliferation. We further analyzed the proteins in the signaling pathway of regulation of the cytoskeleton using a proteomic approach and found upregulation of IQGAP1, gelsolin, moesin, radixin, and Cfl1. After analyzing the focal adhesion signaling pathway, we found the upregulation of FLNA, LAMA1, LAMA5, COL1A1, COL3A1, COL4A6, and COL5A2 as well as the downregulation of COL4A1, COL4A2, and COL4A4. In conclusion, the signaling pathway of regulation of the cytoskeleton and focal adhesion play critical roles in regulating cell spreading and actin skeleton formation in the early stage of osteoblast differentiation.

  2. Crystal Morphologies of Organolead Trihalide in Mesoscopic/Planar Perovskite Solar Cells.

    PubMed

    Zhou, Yuanyuan; Vasiliev, Alexander L; Wu, Wenwen; Yang, Mengjin; Pang, Shuping; Zhu, Kai; Padture, Nitin P

    2015-06-18

    The crystal morphology of organolead trihalide perovskite (OTP) light absorbers can have profound influence on the perovskite solar cells (PSCs) performance. Here we have used a combination of conventional transmission electron microscopy (TEM) and high-resolution TEM (HRTEM), in cross-section and plan-view, to characterize the morphologies of a solution-processed OTP (CH3NH3PbI3 or MAPbI3) within mesoporous TiO2 scaffolds and within capping and planar layers. Studies of TEM specimens prepared with and without the use of focused ion beam (FIB) show that FIBing is a viable method for preparing TEM specimens. HRTEM studies, in conjunction with quantitative X-ray diffraction, show that MAPbI3 perovskite within mesoporous TiO2 scaffold has equiaxed grains of size 10-20 nm and relatively low crystallinity. In contrast, the grain size of MAPbI3 perovskite in the capping and the planar layers can be larger than 100 nm in our PSCs, and the grains can be elongated and textured, with relatively high crystallinity. The observed differences in the performance of planar and mesoscopic-planar hybrid PSCs can be attributed in part to the striking differences in their perovskite-grain morphologies.

  3. Genomic variations leading to alterations in cell morphology of Campylobacter spp

    PubMed Central

    Esson, Diane; Mather, Alison E.; Scanlan, Eoin; Gupta, Srishti; de Vries, Stefan P. W.; Bailey, David; Harris, Simon R.; McKinley, Trevelyan J.; Méric, Guillaume; Berry, Sophia K.; Mastroeni, Pietro; Sheppard, Samuel K.; Christie, Graham; Thomson, Nicholas R.; Parkhill, Julian; Maskell, Duncan J.; Grant, Andrew J.

    2016-01-01

    Campylobacter jejuni, the most common cause of bacterial diarrhoeal disease, is normally helical. However, it can also adopt straight rod, elongated helical and coccoid forms. Studying how helical morphology is generated, and how it switches between its different forms, is an important objective for understanding this pathogen. Here, we aimed to determine the genetic factors involved in generating the helical shape of Campylobacter. A C. jejuni transposon (Tn) mutant library was screened for non-helical mutants with inconsistent results. Whole genome sequence variation and morphological trends within this Tn library, and in various C. jejuni wild type strains, were compared and correlated to detect genomic elements associated with helical and rod morphologies. All rod-shaped C. jejuni Tn mutants and all rod-shaped laboratory, clinical and environmental C. jejuni and Campylobacter coli contained genetic changes within the pgp1 or pgp2 genes, which encode peptidoglycan modifying enzymes. We therefore confirm the importance of Pgp1 and Pgp2 in the maintenance of helical shape and extended this to a wide range of C. jejuni and C. coli isolates. Genome sequence analysis revealed variation in the sequence and length of homopolymeric tracts found within these genes, providing a potential mechanism of phase variation of cell shape. PMID:27910897

  4. Streptomyces natalensis programmed cell death and morphological differentiation are dependent on oxidative stress

    PubMed Central

    Beites, Tiago; Oliveira, Paulo; Rioseras, Beatriz; Pires, Sílvia D. S.; Oliveira, Rute; Tamagnini, Paula; Moradas-Ferreira, Pedro; Manteca, Ángel; Mendes, Marta V.

    2015-01-01

    Streptomyces are aerobic Gram-positive bacteria characterized by a complex life cycle that includes hyphae differentiation and spore formation. Morphological differentiation is triggered by stressful conditions and takes place in a pro-oxidant environment, which sets the basis for an involvement of the oxidative stress response in this cellular process. Characterization of the phenotypic traits of Streptomyces natalensis ΔkatA1 (mono-functional catalase) and ΔcatR (Fur-like repressor of katA1 expression) strains in solid medium revealed that both mutants had an impaired morphological development process. The sub-lethal oxidative stress caused by the absence of KatA1 resulted in the formation of a highly proliferative and undifferentiated vegetative mycelium, whereas de-repression of CatR regulon, from which KatA1 is the only known representative, resulted in the formation of scarce aerial mycelium. Both mutant strains had the transcription of genes associated with aerial mycelium formation and biosynthesis of the hyphae hydrophobic layer down-regulated. The first round of the programmed cell death (PCD) was inhibited in both strains which caused the prevalence of the transient primary mycelium (MI) over secondary mycelium (MII). Our data shows that the first round of PCD and morphological differentiation in S. natalensis is dependent on oxidative stress in the right amount at the right time. PMID:26256439

  5. Foveolar Müller Cells of the Pied Flycatcher: Morphology and Distribution of Intermediate Filaments Regarding Cell Transparency.

    PubMed

    Zueva, Lidia; Golubeva, Tatiana; Korneeva, Elena; Makarov, Vladimir; Khmelinskii, Igor; Inyushin, Mikhail

    2016-04-01

    Specialized intermediate filaments (IFs) have critical importance for the clearness and uncommon transparency of vertebrate lens fiber cells, although the physical mechanisms involved are poorly understood. Recently, an unusual low-scattering light transport was also described in retinal Müller cells. Exploring the function of IFs in Müller cells, we have studied the morphology and distribution pattern of IFs and other cytoskeletal filaments inside the Müller cell main processes in the foveolar part of the avian (pied flycatcher) retina. We found that some IFs surrounded by globular nanoparticles (that we suggest are crystallines) are present in almost every part of the Müller cells that span the retina, including the microvilli. Unlike IFs implicated in the mechanical architecture of the cell, these IFs are not connected to any specific cellular membranes. Instead, they are organized into bundles, passing inside the cell from the endfeet to the photoreceptor, following the geometry of the processes, and repeatedly circumventing numerous obstacles. We believe that the presently reported data effectively confirm that the model of nanooptical channels built of the IFs may provide a viable explanation of Müller cell transparency.

  6. Morphological, Biochemical, and Functional Study of Viral Replication Compartments Isolated from Adenovirus-Infected Cells

    PubMed Central

    Hidalgo, Paloma; Anzures, Lourdes; Hernández-Mendoza, Armando; Guerrero, Adán; Wood, Christopher D.; Valdés, Margarita; Dobner, Thomas

    2016-01-01

    ABSTRACT Adenovirus (Ad) replication compartments (RC) are nuclear microenvironments where the viral genome is replicated and a coordinated program of late gene expression is established. These virus-induced nuclear sites seem to behave as central hubs for the regulation of virus-host cell interactions, since proteins that promote efficient viral replication as well as factors that participate in the antiviral response are coopted and concentrated there. To gain further insight into the activities of viral RC, here we report, for the first time, the morphology, composition, and activities of RC isolated from Ad-infected cells. Morphological analyses of isolated RC particles by superresolution microscopy showed that they were indistinguishable from RC within infected cells and that they displayed a dynamic compartmentalization. Furthermore, the RC-containing fractions (RCf) proved to be functional, as they directed de novo synthesis of viral DNA and RNA as well as RNA splicing, activities that are associated with RC in vivo. A detailed analysis of the production of viral late mRNA from RCf at different times postinfection revealed that viral mRNA splicing occurs in RC and that the synthesis, posttranscriptional processing, and release from RC to the nucleoplasm of individual viral late transcripts are spatiotemporally separate events. The results presented here demonstrate that RCf are a powerful system for detailed study into RC structure, composition, and activities and, as a result, the determination of the molecular mechanisms that induce the formation of these viral sites of adenoviruses and other nuclear-replicating viruses. IMPORTANCE RC may represent molecular hubs where many aspects of virus-host cell interaction are controlled. Here, we show by superresolution microscopy that RCf have morphologies similar to those of RC within Ad-infected cells and that they appear to be compartmentalized, as nucleolin and DBP display different localization in the

  7. Micrometer scale spacings between fibronectin nanodots regulate cell morphology and focal adhesions

    NASA Astrophysics Data System (ADS)

    Horzum, Utku; Ozdil, Berrin; Pesen-Okvur, Devrim

    2014-04-01

    Cell adhesion to extracellular matrix is an important process for both health and disease states. Surface protein patterns that are topographically flat, and do not introduce other chemical, topographical or rigidity related functionality and, more importantly, that mimic the organization of the in vivo extracellular matrix are desired. Previous work showed that vinculin and cytoskeletal organization are modulated by size and shape of surface nanopatterns. However, quantitative analysis on cell morphology and focal adhesions as a function of micrometer scale spacings of FN nanopatterns was absent. Here, electron beam lithography was used to pattern fibronectin nanodots with micrometer scale spacings on a K-casein background on indium tin oxide coated glass which, unlike silicon, is transparent and thus suitable for many light microscopy techniques. Exposure times were significantly reduced using the line exposure mode with micrometer scale step sizes. Micrometer scale spacings of 2, 4 and 8 μm between fibronectin nanodots proved to modulate cell adhesion through modification of cell area, focal adhesion number, size and circularity. Overall, cell behavior was shown to shift at the apparent threshold of 4 μm spacing. The findings presented here offer exciting new opportunities for cell biology research.

  8. A spectral graph theoretic approach to quantification and calibration of collective morphological differences in cell images

    PubMed Central

    Lin, Yu-Shi; Lin, Chung-Chih; Tsai, Yuh-Show; Ku, Tien-Chuan; Huang, Yi-Hung; Hsu, Chun-Nan

    2010-01-01

    Motivation: High-throughput image-based assay technologies can rapidly produce a large number of cell images for drug screening, but data analysis is still a major bottleneck that limits their utility. Quantifying a wide variety of morphological differences observed in cell images under different drug influences is still a challenging task because the result can be highly sensitive to sampling and noise. Results: We propose a graph-based approach to cell image analysis. We define graph transition energy to quantify morphological differences between image sets. A spectral graph theoretic regularization is applied to transform the feature space based on training examples of extremely different images to calibrate the quantification. Calibration is essential for a practical quantification method because we need to measure the confidence of the quantification. We applied our method to quantify the degree of partial fragmentation of mitochondria in collections of fluorescent cell images. We show that with transformation, the quantification can be more accurate and sensitive than that without transformation. We also show that our method outperforms competing methods, including neighbourhood component analysis and the multi-variate drug profiling method by Loo et al. We illustrate its utility with a study of Annonaceous acetogenins, a family of compounds with drug potential. Our result reveals that squamocin induces more fragmented mitochondria than muricin A. Availability: Mitochondrial cell images, their corresponding feature sets (SSLF and WSLF) and the source code of our proposed method are available at http://aiia.iis.sinica.edu.tw/. Contact: chunnan@iis.sinica.edu.tw Supplementary information: Supplementary data are available at Bioinformatics online. PMID:20529919

  9. GNG11 (G-protein γ subunit 11) suppresses cell growth with induction of reactive oxygen species and abnormal nuclear morphology in human SUSM-1 cells.

    PubMed

    Takauji, Yuki; Kudo, Ikuru; En, Atsuki; Matsuo, Ryo; Hossain, Mohammad; Nakabayashi, Kazuhiko; Miki, Kensuke; Fujii, Michihiko; Ayusawa, Dai

    2017-04-05

    Enforced expression of GNG11, G-protein γ subunit 11, induces cellular senescence in normal human diploid fibroblasts. We here examined the effect of the expression of GNG11 on the growth of immortalized human cell lines, and found that it suppressed the growth of SUSM-1 cells, but not of HeLa cells. We then compared these two cell lines to understand the molecular basis for the action of GNG11. We found that expression of GNG11 induced the generation of reactive oxygen species (ROS) and abnormal nuclear morphology in SUSM-1 cells but not in HeLa cells. Increased ROS generation by GNG11 would likely be caused by the down-regulation of the antioxidant enzymes in SUSM-1 cells. We also found that SUSM-1 cells, even under normal culture conditions, showed higher levels of ROS and higher incidence of abnormal nuclear morphology than HeLa cells, and that abnormal nuclear morphology was relevant to the increased ROS generation in SUSM-1 cells. Thus, SUSM-1 and HeLa cells showed differences in the regulation of ROS and nuclear morphology, which might account for their different responses to the expression of GNG11. Then, SUSM-1 cells may provide a unique system to study the regulatory relationship between ROS generation, nuclear morphology, and G-protein signaling.

  10. The influence of the amorphous polymer on conductivity, morphologies and thermal properties of polyether-based blends with addition of inorganic salt

    NASA Astrophysics Data System (ADS)

    Chan, C. H.; Sim, L. H.; Kammer, H. W.; Tan, W.

    2012-06-01

    Thermodynamic control of the dispersion of lithium (Li) salt in different phases of semicrystalline/amorphous polymer blends is elucidated in this study. Solid polymer electrolytes of poly(ethylene oxide) (PEO), epoxidized natural rubber (ENR), random copolymer of poly(acrylate) (PAc) and as well as polymer blends of PEO with ENR and PAc doped with various concentrations of Li salt were studied. The salt concentrations (CLi) of solid polymer electrolytes vary between CLi = 0.02 and 0.15. The influence of the ENR or PAc on the properties of PEO after addition of Li salt is discussed. Blends of PEO/ENR and PEO/PAc are immiscible by elucidation of the glass transition temperature (Tg) as well as the morphological analyses. PEO, ENR and PAc possess oxygen in their respective chemical structures, which may be able to coordinate with the Li salt added. Non uniformity of Li salt concentration in different phases of the blends is highlighted for both systems. The conductivity of PEO/ENR and PEO/PAc blends doped with Li salt is primarily governed by PEO. The results for Tg suggest that higher solubility of Li salt in PEO as compared to ENR in the former case and restricted ion transport in the glassy PAc (with Tg≈30°C after addition of Li salt in the latter system. These may be the attributing factors for the enhancement of conductivity of the doped-PEO/ENR blends as compared to that of the doped-PEO/PAc blends. This suggests that PEO exhibits greater extent of complexation with LiClO4 as compared to that of the ENR and PAc as supported by Fourier-transform infra-red (FTIR) studies.

  11. CD34+ stromal cells/fibroblasts/fibrocytes/telocytes as a tissue reserve and a principal source of mesenchymal cells. Location, morphology, function and role in pathology.

    PubMed

    Díaz-Flores, L; Gutiérrez, R; García, M P; Sáez, F J; Díaz-Flores, L; Valladares, F; Madrid, J F

    2014-07-01

    We review the morphofunctional characteristics of CD34+ stromal fibroblastic/fibrocytic cells (CD34+ SFCs) and report our observations. We consider the following aspects of CD34+ SFCs: A) The confusing terms applied to this cell type, often combining the prefix CD34 with numerous names, including fibroblasts, fibrocytes, dendrocytes, keratocytes, telocytes and stromal, dendritic, adventitial, supraadventitial, perivascular, paravascular and delimiting cells; B) Changes in their immunophenotype, e.g., loss of CD34 expression and gain of other markers, such as those defining mesenchymal and derivate cells (myofibroblasts, osteoblasts, chondroblasts, adipocytes); C) Morphology (elongated or triangular cell body and thin, moniliform, bipolar or multipolar cytoplasmic processes), immunohistochemistry (co-expression of and changes in molecular expression) and structure (characteristics of nucleus and cytoplasmic organelles, and points of contact and junctions in quiescent and activated stages by light and electron microscopy); D) Location and distribution in the vessels (adventitia or external layer), in the tissues (connective, adipose, blood, muscle and nervous) and in the organs and systems (skin, oral cavity and oropharynx, respiratory, digestive, urinary, male, female, endocrine and lymphoid systems, serosal and synovial membranes, heart, eye and meninges); E) Origin from the mesoderm and cranial neural crest in the embryo, and from stem cells (themselves or other cells) and/or peripheral blood pluripotent stem cells (circulating progenitor cells) in post-natal life; F) Functions, such as synthesis of different molecules, progenitor of mesenchymal cells, immunomodulation, parenchymal regulation (growth, maturation and differentiation of adjacent cells), induction of angiogenesis, scaffolding support of other cells and phagocytic properties. Since CD34+ SFCs are the main reservoir of tissue mesenchymal cells (great mesenchymal potential, probably higher than that

  12. Melanopsin‐expressing ganglion cells on macaque and human retinas form two morphologically distinct populations

    PubMed Central

    Liao, Hsi‐Wen; Ren, Xiaozhi; Peterson, Beth B.; Marshak, David W.; Yau, King‐Wai; Gamlin, Paul D.

    2016-01-01

    ABSTRACT The long‐term goal of this research is to understand how retinal ganglion cells that express the photopigment melanopsin, also known as OPN4, contribute to vision in humans and other primates. Here we report the results of anatomical studies using our polyclonal antibody specifically against human melanopsin that confirm and extend previous descriptions of melanopsin cells in primates. In macaque and human retina, two distinct populations of melanopsin cells were identified based on dendritic stratification in either the inner or the outer portion of the inner plexiform layer (IPL). Variation in dendritic field size and cell density with eccentricity was confirmed, and dendritic spines, a new feature of melanopsin cells, were described. The spines were the sites of input from DB6 diffuse bipolar cell axon terminals to the inner stratifying type of melanopsin cells. The outer stratifying melanopsin type received inputs from DB6 bipolar cells via a sparse outer axonal arbor. Outer stratifying melanopsin cells also received inputs from axon terminals of dopaminergic amacrine cells. On the outer stratifying melanopsin cells, ribbon synapses from bipolar cells and conventional synapses from amacrine cells were identified in electron microscopic immunolabeling experiments. Both inner and outer stratifying melanopsin cell types were retrogradely labeled following tracer injection in the lateral geniculate nucleus (LGN). In addition, a method for targeting melanopsin cells for intracellular injection using their intrinsic fluorescence was developed. This technique was used to demonstrate that melanopsin cells were tracer coupled to amacrine cells and would be applicable to electrophysiological experiments in the future. J. Comp. Neurol. 524:2845–2872, 2016. © 2016 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc. PMID:26972791

  13. Impact of electrolyte solvent and additive choices on high voltage Li-ion pouch cells

    NASA Astrophysics Data System (ADS)

    Xia, Jian; Nelson, K. J.; Lu, Zhonghua; Dahn, J. R.

    2016-10-01

    The effects that various electrolyte solvents and electrolyte additives had on both LaPO4-coated LiNi0.4Mn0.4Co0.2O2 and uncoated LiNi0.4Mn0.4Co0.2O2/graphite pouch cells were studied using automated storage, electrochemical impedance spectroscopy, gas production and long-term cycling experiments. Storage experiments showed that the voltage drop during storage at 4.3 or 4.4 V for both coated and uncoated cells was very similar for the same electrolyte choice. At 4.5 V or above, the LaPO4-coated cells had a significantly smaller voltage drop than the uncoated cells except when fluorinated electrolytes were used. Automated charge discharge cycling/impedance spectroscopy testing of cells held at 4.5 V for 24 h every cycle showed that all cells containing ethylene carbonate:ethyl methyl carbonate electrolyte or sulfolane:ethyl methyl carbonate electrolyte exhibited severe capacity fade. By contrast, cells containing fluorinated electrolytes had the best capacity retention and smallest impedance growth during these aggressive cycling/hold tests. Long-term cycling experiments to 4.5 V confirmed that cells containing fluorinated electrolyte had the best cycling performance in the uncoated LiNi0.4Mn0.4Co0.2O2/graphite cells while cells containing sulfolane:ethyl methyl carbonate electrolyte had the best cycling performance in coated LiNi0.4Mn0.4Co0.2O2/graphite cells.

  14. Active dentate granule cells encode experience to promote the addition of adult-born hippocampal neurons.

    PubMed

    Kirschen, Gregory W; Shen, Jia; Tian, Mu; Schroeder, Bryce; Wang, Jia; Man, Guoming; Wu, Song; Ge, Shaoyu

    2017-04-03

    The continuous addition of new dentate granule cells, exquisitely regulated by brain activity, renders the hippocampus plastic. However, how neural circuits encode experiences to impact the addition of adult-born neurons remains unknown. Here, we used endoscopic Ca(2+) imaging to track the real-time activity of individual dentate granule cells in freely-behaving mice. For the first time, we found that active dentate granule cells responded to a novel experience by preferentially increasing their Ca(2+) event frequency. This elevated activity, which we found to be associated with object exploration, returned to baseline by one hour in the same environment, but could be dishabituated via introduction to a novel environment. To seamlessly transition between environments, we next established a freely-controllable virtual reality system for unrestrained mice. We again observed increased firing of active neurons in a virtual enriched environment. Interestingly, multiple novel virtual experiences accumulatively increased the number of newborn neurons when compared to a single experience. Finally, optogenetic silencing of existing dentate granule cells during novel environmental exploration perturbed experience-induced neuronal addition. Together, our study shows that the adult brain conveys novel, enriched experiences to increase the addition of adult-born hippocampal neurons by increasing the firing of active dentate granule cells.SIGNIFICANCE STATEMENTAdult brains are constantly reshaping themselves from synapses to circuits as we encounter novel experiences from moment to moment. Importantly, this reshaping includes the addition of newborn hippocampal neurons. However, it remains largely unknown how our circuits encode experience-induced brain activity to govern the addition of new hippocampal neurons. By coupling in vivo Ca(2+) imaging of dentate granule neurons with a novel unrestrained virtual reality system for rodents, we discovered that a new experience rapidly

  15. Effects of NaOH addition on performance of the direct hydrazine fuel cell

    NASA Astrophysics Data System (ADS)

    Yin, Wen Xia; Li, Zhou Peng; Zhu, Jing Ke; Qin, Hai Ying

    In this work, we suggested a figuration of the direct hydrazine fuel cell (DHFC) using non-precious metals as the anode catalyst, ion exchange membranes as the electrolyte and alkaline hydrazine solutions as the fuel. NaOH addition in the anolyte effectively improved the open circuit voltage and the performance of the DHFC. A power density of 84 mW cm -2 has been achieved when operating the cell at room temperature. It was found that the cell performance was mainly influenced by anode polarization when using alkaline N 2H 4 solutions with low NaOH concentrations. However, when using alkaline N 2H 4 solutions with high NaOH concentrations as the fuel, the cell performance was mainly influenced by cathode polarization.

  16. Poly iron sulfate flocculant as an effective additive for improving the performance of microbial fuel cells.

    PubMed

    Miyahara, Morio; Sakamoto, Akihiro; Kouzuma, Atsushi; Watanabe, Kazuya

    2016-12-01

    Laboratory microbial fuel cells were supplied with artificial wastewater and used to examine how supplementation with poly iron sulfate, an inorganic polymer flocculant widely used in wastewater-treatment plants, affects electricity generation and anode microbiomes. It is shown that poly iron sulfate substantially increases electric outputs from microbial fuel cells. Microbiological analyses show that iron and sulfate separately affect anode microbiomes, and the increase in power output is associated with the increases in bacteria affiliated with the families Geobacteraceae and/or Desulfuromonadaceae. We suggest that poly iron sulfate is an effective additive for increasing the electric output from microbial fuel cells. Other utilities of poly iron sulfate in microbial fuel cells are also discussed.

  17. Prolonged cold storage of red blood cells by oxygen removal and additive usage

    DOEpatents

    Bitensky, Mark W.; Yoshida, Tatsuro

    1998-01-01

    Prolonged cold storage of red blood cells by oxygen removal and additive usage. A cost-effective, 4.degree. C. storage procedure that preserves red cell quality and prolongs post-transfusion in vivo survival is described. The improved in vivo survival and the preservation of adenosine triphosphate levels, along with reduction in hemolysis and membrane vesicle production of red blood cells stored at 4.degree. C. for prolonged periods of time, is achieved by reducing the oxygen level therein at the time of storage; in particular, by flushing the cells with an inert gas, and storing them in an aqueous solution which includes adenine, dextrose, mannitol, citrate ion, and dihydrogen phosphate ion, but no sodium chloride, in an oxygen-permeable container which is located in an oxygen-free environment containing oxygen-scavenging materials.

  18. Prolonged cold storage of red blood cells by oxygen removal and additive usage

    DOEpatents

    Bitensky, M.W.; Yoshida, Tatsuro

    1998-08-04

    Prolonged cold storage of red blood cells by oxygen removal and additive usage. A cost-effective, 4 C storage procedure that preserves red cell quality and prolongs post-transfusion in vivo survival is described. The improved in vivo survival and the preservation of adenosine triphosphate levels, along with reduction in hemolysis and membrane vesicle production of red blood cells stored at 4 C for prolonged periods of time, is achieved by reducing the oxygen level therein at the time of storage; in particular, by flushing the cells with an inert gas, and storing them in an aqueous solution which includes adenine, dextrose, mannitol, citrate ion, and dihydrogen phosphate ion, but no sodium chloride, in an oxygen-permeable container which is located in an oxygen-free environment containing oxygen-scavenging materials. 8 figs.

  19. Complex morphology of gastrin-releasing G-cells in the antral region of the mouse stomach.

    PubMed

    Frick, Claudia; Rettenberger, Amelie Therese; Lunz, Malena Luisa; Breer, Heinz

    2016-11-01

    Gastrin-releasing enteroendocrine cells (G-cells) are usually described as flask-shaped cells with a large base and a small apical pole, integrated in the epithelium lining the basal region of the antral invaginations in the stomach. By means of a transgenic mouse line in which the enhanced version of GFP is endogenously expressed under the control of a gastrin promoter, we have analyzed the spatial distribution and morphological features of G-cells. We found that G-cells were not only located at the basal region of the invagination but to a lesser extent also at the upper region. Visualization of the entire cellular morphology revealed that G-cells show complex morphologies. Basally located G-cells are roundish-shaped cells which project a prominent apical process towards the lumen and extend basal protrusions containing the hormone gastrin that were frequently found in close proximity to blood vessels and occasionally in the vicinity of nerve fibers. Inspection of G-cells in the upper region of antral invaginations disclosed a novel population of G-cells. These cells have a spindle-like contour and long apical and basal processes which extend vertically along the antral invagination, parallel to the lumen. This G-cell population seems to be in contact with a network of nerve fibers. While the functional role of these untypical G-cells is still elusive, the results of this study provide some useful indications to possible roles of these G-cells.

  20. Efficiency improvement using bis(trifluoromethane) sulfonamide lithium salt as a chemical additive in porphyrin based organic solar cells.

    PubMed

    Arrechea, Susana; Aljarilla, Ana; de la Cruz, Pilar; Palomares, Emilio; Sharma, Ganesh D; Langa, Fernando

    2016-10-20

    Two new conjugated acceptor-π-donor-π-acceptor (A-π-D-π-A) porphyrins have been synthesised using 3-ethylrhodanine (1a) or dicyanovinylene (1b) groups as acceptor units. Their optical and electrochemical properties made these materials excellent electron donors along with PC71BM as the acceptor for solution-processed bulk heterojunction organic solar cells. The devices based on 1a:PC71BM (1 : 2) and 1b:PC71BM (1 : 2) processed with CB showed low power conversion efficiencies (PCE) of 2.30% and 2.80%, respectively. Nonetheless, after processing the active layer using a mixture of 3 vol% of a pyridine additive in THF, the PCE was enhanced up to 5.14% and 6.06% for 1a:PC71BM and 1b:PC71BM, respectively. Moreover, when we used LiTFSI as the chemical additive in pyridine/CB-processed 1b:PC71BM an excellent PCE of 7.63% was recorded. The effects over the film morphology and the device characteristics (Jsc, Voc and FF) due to the introduction of LiTFSI are discussed.

  1. Some Lewis acid-base adducts involving boron trifluoride as electrolyte additives for lithium ion cells

    NASA Astrophysics Data System (ADS)

    Nie, Mengyun; Madec, L.; Xia, J.; Hall, D. S.; Dahn, J. R.

    2016-10-01

    Three complexes with boron trifluoride (BF3) as the Lewis acid and different Lewis bases were synthesized and used as electrolyte additives in Li[Ni1/3Mn1/3Co1/3]O2/graphite and Li[Ni0.42Mn0.42Co0.16]O2/graphite pouch cells. Lewis acid-base adducts with a boron-oxygen (Bsbnd O) bond were trimethyl phosphate boron trifluoride (TMP-BF) and triphenyl phosphine oxide boron trifluoride (TPPO-BF). These were compared to pyridine boron trifluoride (PBF) which has a boron-nitrogen (Bsbnd N) bond. The experimental results showed that cells with PBF had the least voltage drop during storage at 4.2 V, 4.4 V and 4.7 V at 40 °C and the best capacity retention during long-term cycling at 55 °C compared to cells with the other additives. Charge-hold-discharge cycling combined with simultaneous electrochemical impedance spectroscopy measurements showed that impedance growth in TMP-BF and TPPO-BF containing cells was faster than cells containing 2%PBF, suggesting that PBF is useful for impedance control at high voltages (>4.4 V). XPS analysis of the SEI films highlighted a specific reactivity of the PBF-derived SEI species that apparently hinders the degradation of both LiPF6 and solvent during formation and charge-hold-discharge cycling. The modified SEI films may explain the improved impedance, the smaller voltage drop during storage and the improved capacity retention during cycling of cells containing the PBF additive.

  2. Acinic Cell Carcinoma of the Parotid Gland with Four Morphological Features

    PubMed Central

    Rosero, David S; Alvarez, Ramiro; Gambó, Paula; Alastuey, María; Valero, Alberto; Torrecilla, Nerea; Roche, A. Belén; Simón, Sara

    2016-01-01

    Acinic cell carcinoma arising in salivary glands is a rare tumor, accounting for 2% to 5% of the primary neoplasms of the parotid gland. When these tumors are well-differentiated, the neoplasia has innocuous aspect, due to the similarity to normal parotid tissue. This makes the diagnosis difficult. Initially the malignancy of this tumor was uncertain; however, recent studies have declared it as malignant. The female / male ratio is 3:2. The nodule usually presents as solitary and well defined shape. Several authors have used different terms to describe histomorphological patterns of these tumors. Four descriptive categories (solid, microcystic, papillary-cystic and follicular) are useful for pathologists. Here we report a case of a 49 yr old man with a left parotid nodule of 5 cm. Parotidectomy was performed at the Hospital Universitario Miguel Servet, in Zaragoza (Spain). The microscopy showed a tumor with acinic semblance, having the four morphologic patterns previously described. The morphological and immunohistochemical study was consistent with the diagnosis of acinic cell carcinoma. PMID:27499783

  3. DamX Controls Reversible Cell Morphology Switching in Uropathogenic Escherichia coli

    PubMed Central

    Khandige, Surabhi; Asferg, Cecilie Antoinette; Rasmussen, Karina Juhl; Larsen, Martin Jakob; Overgaard, Martin

    2016-01-01

    ABSTRACT The ability to change cell morphology is an advantageous characteristic adopted by multiple pathogenic bacteria in order to evade host immune detection and assault during infection. Uropathogenic Escherichia coli (UPEC) exhibits such cellular dynamics and has been shown to transition through a series of distinct morphological phenotypes during a urinary tract infection. Here, we report the first systematic spatio-temporal gene expression analysis of the UPEC transition through these phenotypes by using a flow chamber-based in vitro infection model that simulates conditions in the bladder. This analysis revealed a novel association between the cell division gene damX and reversible UPEC filamentation. We demonstrate a lack of reversible bacterial filamentation in a damX deletion mutant in vitro and absence of a filamentous response by this mutant in a murine model of cystitis. While deletion of damX abrogated UPEC filamentation and secondary surface colonization in tissue culture and in mouse infections, transient overexpression of damX resulted in reversible UPEC filamentation. In this study, we identify a hitherto-unknown damX-mediated mechanism underlying UPEC morphotypical switching. Murine infection studies showed that DamX is essential for establishment of a robust urinary tract infection, thus emphasizing its role as a mediator of virulence. Our study demonstrates the value of an in vitro methodology, in which uroepithelium infection is closely simulated, when undertaking targeted investigations that are challenging to perform in animal infection models. PMID:27486187

  4. Quantitative analysis of mitochondrial morphology and membrane potential in living cells using high-content imaging, machine learning, and morphological binning.

    PubMed

    Leonard, Anthony P; Cameron, Robert B; Speiser, Jaime L; Wolf, Bethany J; Peterson, Yuri K; Schnellmann, Rick G; Beeson, Craig C; Rohrer, Bärbel

    2015-02-01

    Understanding the processes of mitochondrial dynamics (fission, fusion, biogenesis, and mitophagy) has been hampered by the lack of automated, deterministic methods to measure mitochondrial morphology from microscopic images. A method to quantify mitochondrial morphology and function is presented here using a commercially available automated high-content wide-field fluorescent microscopy platform and R programming-language-based semi-automated data analysis to achieve high throughput morphological categorization (puncta, rod, network, and large & round) and quantification of mitochondrial membrane potential. In conjunction with cellular respirometry to measure mitochondrial respiratory capacity, this method detected that increasing concentrations of toxicants known to directly or indirectly affect mitochondria (t-butyl hydroperoxide [TBHP], rotenone, antimycin A, oligomycin, ouabain, and carbonyl cyanide-p-trifluoromethoxyphenylhydrazone [FCCP]), decreased mitochondrial networked areas in cultured 661w cells to 0.60-0.80 at concentrations that inhibited respiratory capacity to 0.20-0.70 (fold change compared to vehicle). Concomitantly, mitochondrial swelling was increased from 1.4- to 2.3-fold of vehicle as indicated by changes in large & round areas in response to TBHP, oligomycin, or ouabain. Finally, the automated identification of mitochondrial location enabled accurate quantification of mitochondrial membrane potential by measuring intramitochondrial tetramethylrhodamine methyl ester (TMRM) fluorescence intensity. Administration of FCCP depolarized and administration of oligomycin hyperpolarized mitochondria, as evidenced by changes in intramitochondrial TMRM fluorescence intensities to 0.33- or 5.25-fold of vehicle control values, respectively. In summary, this high-content imaging method accurately quantified mitochondrial morphology and membrane potential in hundreds of thousands of cells on a per-cell basis, with sufficient throughput for pharmacological

  5. Influence of electrolyte co-additives on the performance of dye-sensitized solar cells

    PubMed Central

    2011-01-01

    The presence of specific chemical additives in the redox electrolyte results in an efficient increase of the photovoltaic performance of dye-sensitized solar cells (DSCs). The most effective additives are 4-tert-butylpyridine (TBP), N-methylbenzimidazole (NMBI) and guanidinium thiocyanate (GuNCS) that are adsorbed onto the photoelectrode/electrolyte interface, thus shifting the semiconductor's conduction band edge and preventing recombination with triiodides. In a comparative work, we investigated in detail the action of TBP and NMBI additives in ionic liquid-based redox electrolytes with varying iodine concentrations, in order to extract the optimum additive/I2 ratio for each system. Different optimum additive/I2 ratios were determined for TBP and NMBI, despite the fact that both generally work in a similar way. Further addition of GuNCS in the optimized electrolytic media causes significant synergistic effects, the action of GuNCS being strongly influenced by the nature of the corresponding co-additive. Under the best operation conditions, power conversion efficiencies as high as 8% were obtained. PMID:21711833

  6. Wrinkled, wavelength-tunable graphene-based surface topographies for directing cell alignment and morphology

    PubMed Central

    Wang, Zhongying; Tonderys, Daniel; Leggett, Susan E.; Williams, Evelyn Kendall; Kiani, Mehrdad T.; Steinberg, Ruben Spitz; Qiu, Yang; Wong, Ian Y.; Hurt, Robert H.

    2015-01-01

    Textured surfaces with periodic topographical features and long-range order are highly attractive for directing cell-material interactions. They mimic physiological environments more accurately than planar surfaces and can fundamentally alter cell alignment, shape, gene expression, and cellular assembly into superstructures or microtissues. Here we demonstrate for the first time that wrinkled graphene-based surfaces are suitable as textured cell attachment substrates, and that engineered wrinkling can dramatically alter cell alignment and morphology. The wrinkled surfaces are fabricated by graphene oxide wet deposition onto pre-stretched elastomers followed by relaxation and mild thermal treatment to stabilize the films in cell culture medium. Multilayer graphene oxide films form periodic, delaminated buckle textures whose wavelengths and amplitudes can be systematically tuned by variation in the wet deposition process. Human and murine fibroblasts attach to these textured films and remain viable, while developing pronounced alignment and elongation relative to those on planar graphene controls. Compared to lithographic patterning of nanogratings, this method has advantages in the simplicity and scalability of fabrication, as well as the opportunity to couple the use of topographic cues with the unique conductive, adsorptive, or barrier properties of graphene materials for functional biomedical devices. PMID:25848137

  7. Cotton fiber tips have diverse morphologies and show evidence of apical cell wall synthesis

    PubMed Central

    Stiff , Michael R.; Haigler, Candace H.

    2016-01-01

    Cotton fibers arise through highly anisotropic expansion of a single seed epidermal cell. We obtained evidence that apical cell wall synthesis occurs through examining the tips of young elongating Gossypium hirsutum (Gh) and G. barbadense (Gb) fibers. We characterized two tip types in Gh fiber (hemisphere and tapered), each with distinct apical diameter, central vacuole location, and distribution of cell wall components. The apex of Gh hemisphere tips was enriched in homogalacturonan epitopes, including a relatively high methyl-esterified form associated with cell wall pliability. Other wall components increased behind the apex including cellulose and the α-Fuc-(1,2)-β-Gal epitope predominantly found in xyloglucan. Gb fibers had only one narrow tip type featuring characters found in each Gh tip type. Pulse-labeling of cell wall glucans indicated wall synthesis at the apex of both Gh tip types and in distal zones. Living Gh hemisphere and Gb tips ruptured preferentially at the apex upon treatment with wall degrading enzymes, consistent with newly synthesized wall at the apex. Gh tapered tips ruptured either at the apex or distantly. Overall, the results reveal diverse cotton fiber tip morphologies and support primary wall synthesis occurring at the apex and discrete distal regions of the tip. PMID:27301434

  8. Morphological signs of apoptosis in axotomized ganglion cells of the rabbit retina.

    PubMed

    Germain, F; Fernández, E; de la Villa, P

    2007-02-09

    Optic nerve section in mammals induces apoptotic death of retinal ganglion cells (RGCs). However, a small population of RGCs survives for a relatively long time. These cells experience significant morphological changes due to the apoptotic process, but some of these changes are not clearly differentiated from those experienced in necrotic cells. In the present work, rabbit RGCs were studied 1 month after optic nerve section using light microscopy after neurobiotin injection, transmission electron microscopy (EM) and scanning electron microscopy (SEM). Apoptosis was identified by terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling and characteristic signs of apoptosis were observed in the EM images. Ultrastructural analyses showed vacuolar degeneration in the cytoplasm and normal cellular structure loss. Signs of membrane changes were observed in axotomized RGCs by SEM. Early changes seen in the cell membrane suggest that axotomy may cause important changes in the cytoskeleton. We conclude that characteristic signs of apoptosis at the cell membrane level are clearly observed in rabbit RGCs after axotomy and they may be responsible for the cellular death.

  9. 4-Vinyl-1,3-Dioxolane-2-One as an Additive for Li-Ion Cells

    NASA Technical Reports Server (NTRS)

    Smart, Marshall; Bugga, Ratnakumar

    2006-01-01

    Electrolyte additive 4-vinyl-1,3-dioxolane-2-one has been found to be promising for rechargeable lithium-ion electrochemical cells. This and other additives, along with advanced electrolytes comprising solutions of LiPF6 in various mixtures of carbonate solvents, have been investigated in a continuing effort to improve the performances of rechargeable lithium-ion electrochemical cells, especially at low temperatures. In contrast to work by other researchers who have investigated the use of this additive to improve the high-temperature resilience of Li-ion cells, the current work involves the incorporation of 4-vinyl-1,3-dioxolane-2-one into quaternary carbonate electrolyte mixtures, previously optimized for low-temperature applications, resulting in improved low-temperature performance. The benefit afforded by 4-vinyl-1,3- dioxolane-2-one can be better understood in the light of relevant information from a number of prior NASA Tech Briefs articles about electrolytes and additives for such cells. To recapitulate: The loss of performance with decreasing temperature is attributable largely to a decrease of ionic conductivity and the increase in viscosity of the electrolyte. What is needed to extend the lower limit of operating temperature is a stable electrolyte solution with relatively small lowtemperature viscosity, a large electric permittivity, adequate coordination behavior, and appropriate ranges of solubilities of liquid and salt constituents. Whether the anode is made of graphitic or non-graphitic carbon, a film on the surface of the anode acts as a solid/electrolyte interface (SEI), the nature of which is critical to low-temperature performance. Desirably, the surface film should exert a chemically protective (passivating) effect on both the anode and the electrolyte, yet should remain conductive to lithium ions to facilitate intercalation and de-intercalation of the ions into and out of the carbon during discharging and charging, respectively. The additives

  10. Zebrafish mesonephric renin cells are functionally conserved and comprise two distinct morphological populations.

    PubMed

    Rider, Sebastien A; Christian, Helen C; Mullins, Linda J; Howarth, Amelia R; MacRae, Calum A; Mullins, John J

    2017-04-01

    Zebrafish provide an excellent model in which to assess the role of the renin-angiotensin system in renal development, injury, and repair. In contrast to mammals, zebrafish kidney organogenesis terminates with the mesonephros. Despite this, the basic functional structure of the nephron is conserved across vertebrates. The relevance of teleosts for studies relating to the regulation of the renin-angiotensin system was established by assessing the phenotype and functional regulation of renin-expressing cells in zebrafish. Transgenic fluorescent reporters for renin (ren), smooth muscle actin (acta2), and platelet-derived growth factor receptor-beta (pdgfrb) were studied to determine the phenotype and secretory ultrastructure of perivascular renin-expressing cells. Whole kidney ren transcription responded to altered salinity, pharmacological renin-angiotensin system inhibition, and renal injury. Mesonephric ren-expressing cells occupied niches at the preglomerular arteries and afferent arterioles, forming intermittent epithelioid-like multicellular clusters exhibiting a granular secretory ultrastructure. In contrast, renin cells of the efferent arterioles were thin bodied and lacked secretory granules. Renin cells expressed the perivascular cell markers acta2 and pdgfrb Transcriptional responses of ren to physiological challenge support the presence of a functional renin-angiotensin system and are consistent with the production of active renin. The reparative capability of the zebrafish kidney was harnessed to demonstrate that ren transcription is a marker for renal injury and repair. Our studies demonstrate substantive conservation of renin regulation across vertebrates, and ultrastructural studies of renin cells reveal at least two distinct morphologies of mesonephric perivascular ren-expressing cells.

  11. Viral morphogenesis and morphological changes in human neuronal cells following Tioman and Menangle virus infection.

    PubMed

    Yaiw, K C; Hyatt, A; Vandriel, R; Crameri, S G; Eaton, B; Wong, M H; Wang, L F; Ng, M L; Bingham, J; Shamala, D; Wong, K T

    2008-01-01

    Tioman virus (TioPV) and Menangle virus (MenPV) are two antigenically and genetically related paramyxoviruses (genus: Rubulavirus, family: Paramyxoviridae) isolated from Peninsular Malaysia (2001) and Australia (1997), respectively. Both viruses are potential zoonotic agents. In the present study, the infectivity, growth kinetics, morphology and morphogenesis of these two paramyxoviruses in a human neuronal cell (SK-N-SH) line were investigated. Sub-confluent SK-N-SH cells were infected with TioPV and MenPV at similar multiplicity of infection. These cells were examined by conventional and immunoelectron microscopy, and virus titres in the supernatants were assayed. Syncytia were observed for both infections in SK-N-SH cells and were more pronounced during the early stages of TioPV infection. The TioPV titre increased consistently (10(1)) every 12 h after infection. In MenPV-infected cells, cellular material was frequently observed within budding virions, and microfilaments and microtubules were abundant. Viral budding was common, and extracellular MenPVs tended to be more pleomorphic compared to TioPVs, which appeared to be more spherical in appearance. The MenPV cytoplasmic viral inclusion appeared to be comparatively smaller, loose and interspersed with randomly scattered circle-like particles, whereas huge tubule-like cytoplasmic inclusions were observed in TioPV-infected cells. Both viruses also displayed different cellular pathology in the SK-N-SH cells. The intracellular ultrastructural characteristics of these two viruses in infected neuronal cells may allow them to be differentiated by electron microscopy.

  12. Androgens Exert a Cysticidal Effect upon Taenia crassiceps by Disrupting Flame Cell Morphology and Function

    PubMed Central

    Ambrosio, Javier R.; Valverde-Islas, Laura; Nava-Castro, Karen E.; Palacios- Arreola, M. Isabel; Ostoa-Saloma, Pedro; Reynoso-Ducoing, Olivia; Escobedo, Galileo; Ruíz-Rosado, Azucena; Dominguez-Ramírez, Lenin; Morales-Montor, Jorge

    2015-01-01

    The effects of testosterone (T4) and dihydrotestosterone (DHT) on the survival of the helminth cestode parasite Taenia crassiceps, as well as their effects on actin, tubulin and myosin expression and their assembly into the excretory system of flame cells are described in this paper. In vitro evaluations on parasite viability, flow cytometry, confocal microscopy, video-microscopy of live flame cells, and docking experiments of androgens interacting with actin, tubulin, and myosin were conducted. Our results show that T4 and DHT reduce T. crassiceps viability in a dose- and time-dependent fashion, reaching 90% of mortality at the highest dose used (40 ng/ml) and time exposed (10 days) in culture. Androgen treatment does not induce differences in the specific expression pattern of actin, tubulin, and myosin isoforms as compared with control parasites. Confocal microscopy demonstrated a strong disruption of the parasite tegument, with reduced assembly, shape, and motion of flame cells. Docking experiments show that androgens are capable of affecting parasite survival and flame cell morphology by directly interacting with actin, tubulin and myosin without altering their protein expression pattern. We show that both T4 and DHT are able to bind actin, tubulin, and myosin affecting their assembly and causing parasite intoxication due to impairment of flame cell function. Live flame cell video microscopy showing a reduced motion as well changes in the shape of flame cells are also shown. In summary, T4 and DHT directly act on T. crassiceps cysticerci through altering parasite survival as well as the assembly and function of flame cells. PMID:26076446

  13. Androgens Exert a Cysticidal Effect upon Taenia crassiceps by Disrupting Flame Cell Morphology and Function.

    PubMed

    Ambrosio, Javier R; Valverde-Islas, Laura; Nava-Castro, Karen E; Palacios-Arreola, M Isabel; Ostoa-Saloma, Pedro; Reynoso-Ducoing, Olivia; Escobedo, Galileo; Ruíz-Rosado, Azucena; Dominguez-Ramírez, Lenin; Morales-Montor, Jorge

    2015-01-01

    The effects of testosterone (T4) and dihydrotestosterone (DHT) on the survival of the helminth cestode parasite Taenia crassiceps, as well as their effects on actin, tubulin and myosin expression and their assembly into the excretory system of flame cells are described in this paper. In vitro evaluations on parasite viability, flow cytometry, confocal microscopy, video-microscopy of live flame cells, and docking experiments of androgens interacting with actin, tubulin, and myosin were conducted. Our results show that T4 and DHT reduce T. crassiceps viability in a dose- and time-dependent fashion, reaching 90% of mortality at the highest dose used (40 ng/ml) and time exposed (10 days) in culture. Androgen treatment does not induce differences in the specific expression pattern of actin, tubulin, and myosin isoforms as compared with control parasites. Confocal microscopy demonstrated a strong disruption of the parasite tegument, with reduced assembly, shape, and motion of flame cells. Docking experiments show that androgens are capable of affecting parasite survival and flame cell morphology by directly interacting with actin, tubulin and myosin without altering their protein expression pattern. We show that both T4 and DHT are able to bind actin, tubulin, and myosin affecting their assembly and causing parasite intoxication due to impairment of flame cell function. Live flame cell video microscopy showing a reduced motion as well changes in the shape of flame cells are also shown. In summary, T4 and DHT directly act on T. crassiceps cysticerci through altering parasite survival as well as the assembly and function of flame cells.

  14. Morphological and biochemical changes during formocresol induced cell death in murine peritoneal macrophages: apoptotic and necrotic features.

    PubMed

    Cardoso, María Lorena; Todaro, Juan Santiago; Aguirre, María Victoria; Juaristi, Julián Antonio; Brandan, Nora Cristina

    2010-10-01

    The present study was conducted to investigate the role of Formocresol (FC)-induced apoptosis and necrotic cell death in murine peritoneal macrophages (pMø). Macrophages were cultured with 1:100 FC for 2 to 24 h. The viability (trypan blue assay), cell morphology (scanning electronic microscope), and apoptotic and necrotic indexes (light and fluorescent microscopy) were determined at different scheduled times. Simultaneously, the expressions of proteins related to stress, survival, and cell death were measured by western blotting. FC-exposed macrophages exhibited maximal apoptosis from 2 to 6 h, coincident with Bax overexpression (P < 0.001). Additionally, Bcl-x(L) showed maximal expression between 12 and 24 h suggesting its survival effect in pMø. The lowest pMø viability and the increment of the necrotic rate from 4 to 12 h were observed in accordance to Fas and Hsp60 overexpressions. In summary, all the experimental data suggest that two different pathways emerge in pMø exposed to FC, one leading Bax-dependent apoptosis (2-6 h) and the other one favoring necrosis (4-18 h), related to Fas-receptor and Hsp60 stress signal.

  15. Alkyl Pyrocarbonate Electrolyte Additives for Performance Enhancement of Li Ion Cells

    NASA Technical Reports Server (NTRS)

    Smart, M. C.; Ratnakumar, B. V.; Surampudi, S.

    2000-01-01

    Lithium ion rechargeable batteries are being developed for various aerospace applications under a NASA-DoD Interagency program. These applications require further improvements in several areas, specifically in the cycle life for LEO and GEO satellites and in the low temperature performance for the Mars Lander and Rover missions. Accordingly, we have been pursuing research studies to achieve improvement in the low temperature performance, long cycle life and active life of Li ion cells. The studies are mainly focused on electrolytes, to identify newer formulations of new electrolyte additives to enhance Li permeability (at low temperatures) and stability towards the electrode. The latter approach is particularly aimed at the formation suitable SEI (solid electrolyte interphase) on carbon electrodes. In this paper, we report the beneficial effect of using alkyl pyrocarbonates as electrolyte additives to improve the low temperature performance of Li ion cells.

  16. Morphological changes and nuclear translocation of DLC1 tumor suppressor protein precede apoptosis in human non-small cell lung carcinoma cells

    SciTech Connect

    Yuan Baozhu Jefferson, Amy M.; Millecchia, Lyndell; Popescu, Nicholas C.; Reynolds, Steven H.

    2007-11-01

    We have previously shown that reactivation of DLC1, a RhoGAP containing tumor suppressor gene, inhibits tumorigenicity of human non-small cell lung carcinoma cells (NSCLC). After transfection of NSCLC cells with wild type (WT) DLC1, changes in cell morphology were observed. To determine whether such changes have functional implications, we generated several DLC1 mutants and examined their effects on cell morphology, proliferation, migration and apoptosis in a DLC1 deficient NSCLC cell line. We show that WT DLC1 caused actin cytoskeleton-based morphological alterations manifested as cytoplasmic extensions and membrane blebbings in most cells. Subsequently, a fraction of cells exhibiting DLC1 protein nuclear translocation (PNT) underwent caspase 3-dependent apoptosis. We also show that the RhoGAP domain is essential for the occurrence of morphological alterations, PNT and apoptosis, and the inhibition of cell migration. DLC1 PNT is dependent on a bipartite nuclear localizing sequence and most likely is regulated by a serine-rich domain at N-terminal part of the DLC1 protein. Also, we found that DLC1 functions in the cytoplasm as an inhibitor of tumor cell proliferation and migration, but in the nucleus as an inducer of apoptosis. Our analyses provide evidence for a possible link between morphological alterations, PNT and proapoptotic and anti-oncogenic activities of DLC1 in lung cancer.