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Sample records for cell blot technique

  1. Single cell-resolution western blotting.

    Science.gov (United States)

    Kang, Chi-Chih; Yamauchi, Kevin A; Vlassakis, Julea; Sinkala, Elly; Duncombe, Todd A; Herr, Amy E

    2016-08-01

    This protocol describes how to perform western blotting on individual cells to measure cell-to-cell variation in protein expression levels and protein state. Like conventional western blotting, single-cell western blotting (scWB) is particularly useful for protein targets that lack selective antibodies (e.g., isoforms) and in cases in which background signal from intact cells is confounding. scWB is performed on a microdevice that comprises an array of microwells molded in a thin layer of a polyacrylamide gel (PAG). The gel layer functions as both a molecular sieving matrix during PAGE and a blotting scaffold during immunoprobing. scWB involves five main stages: (i) gravity settling of cells into microwells; (ii) chemical lysis of cells in each microwell; (iii) PAGE of each single-cell lysate; (iv) exposure of the gel to UV light to blot (immobilize) proteins to the gel matrix; and (v) in-gel immunoprobing of immobilized proteins. Multiplexing can be achieved by probing with antibody cocktails and using antibody stripping/reprobing techniques, enabling detection of 10+ proteins in each cell. We also describe microdevice fabrication for both uniform and pore-gradient microgels. To extend in-gel immunoprobing to gels of small pore size, we describe an optional gel de-cross-linking protocol for more effective introduction of antibodies into the gel layer. Once the microdevice has been fabricated, the assay can be completed in 4-6 h by microfluidic novices and it generates high-selectivity, multiplexed data from single cells. The technique is relevant when direct measurement of proteins in single cells is needed, with applications spanning the fundamental biosciences to applied biomedicine.

  2. APPLICATION OF WESTERN BLOTTING TECHNIQUE FOR EVALUATING THE EXPRESSION OF VASOPRESSIN RECEPTORS IN THE HEART CELLS; IMPORTANCE IN THE CARDIOVASCULAR SYSTEM

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    Manoj G Tyagi

    2012-08-01

    Full Text Available Vasopressin, a posterior pituitary hormone is responsible for water reabsorption by the kidneys and maintenance of cardio-vascular homeostasis. Vasopressin receptors are characterized as VR 1 (V1a, VR2 (V2, and VR3 (V1b. VR1, which is abundant in vascular smooth muscles, causes vasoconstriction by increasing intracellular calcium via the phosphatidylinositol bisphosphonate pathway and a positive inotropic effect in cardiac muscle. VR2 has also been shown to be expressed in the heart. There is emerging role for vasopressin receptors in health and disease. This study describes the application of Western blotting to elucidate the importance of vasopressin receptors in the heart cells.

  3. A Study of Rubisco through Western Blotting and Tissue Printing Techniques

    Science.gov (United States)

    Ma, Zhong; Cooper, Cynthia; Kim, Hyun-Joo; Janick-Buckner, Diane

    2009-01-01

    We describe a laboratory exercise developed for a cell biology course for second-year undergraduate biology majors. It was designed to introduce undergraduates to the basic molecular biology techniques of Western blotting and immunodetection coupled with the technique of tissue printing in detecting the presence, relative abundance, and…

  4. Western blotting as a method for studying cell-biomaterial interactions : The role of protein collection

    NARCIS (Netherlands)

    van Kooten, TG; Klein, CL; Kirkpatrick, CJ

    2001-01-01

    Research of cell-biomaterial interactions is building on knowledge and methods available in cell and molecular biology. Western blotting is one of the options to characterize protein expression in cell populations. Method transfer to biomaterial model systems is not trivial because of the structure

  5. Use of a Western blot technique for the serodiagnosis of glanders

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    de Souza Marcilia MA

    2011-01-01

    Full Text Available Abstract Background The in vivo diagnosis of glanders relies on the highly sensitive complement fixation test (CFT. Frequently observed false positive results are troublesome for veterinary authorities and cause financial losses to animal owners. Consequently, there is an urgent need to develop a test with high specificity. Hence, a Western blot assay making use of a partly purified lipopolysaccaride (LPS containing antigen of three Burkholderia mallei strains was developed. The test was validated investigating a comprehensive set of positive and negative sera obtained from horses and mules from endemic and non endemic areas. Results The developed Western blot assay showed a markedly higher diagnostic specificity when compared to the prescribed CFT and therefore can be used as a confirmatory test. However, the CFT remains the test of choice for routine testing of glanders due to its high sensitivity, its feasibility using standard laboratory equipment and its worldwide distribution in diagnostic laboratories. Conclusions The CFT should be amended by the newly validated Western blot to increase the positive likelihood ratio of glanders serodiagnosis in non endemic areas or areas with low glanders prevalence. Its use for international trade of horses and mules should be implemented by the OIE.

  6. Glyceraldehyde-3-phosphate dehydrogenase: a universal internal control for Western blots in prokaryotic and eukaryotic cells.

    Science.gov (United States)

    Wu, Yonghong; Wu, Min; He, Guowei; Zhang, Xiao; Li, Weiguang; Gao, Yan; Li, Zhihui; Wang, Zhaoyan; Zhang, Chenggang

    2012-04-01

    In the current study, we examined the expression level of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) protein in a number of organisms and the stability of GAPDH under various conditions. Our results revealed that GAPDH is present in multiple Escherichia coli strains, the yeast strain GS115, Caenorhabditis elegans, rat PC12 cells, and both mouse and rat brain. Furthermore, GAPDH was stably expressed under different concentrations of inducer and at different times of induction in E. coli (BL21) cells and yeast GS115 cells. Stable expression of GAPDH protein was also observed in C.elegans and PC12 cells that were treated with different concentrations of paraquat or sodium sulfite, respectively. In addition, we were able to detect and identify the endogenous gapA protein in E.coli via immunoprecipitation and MALDI-TOF-MS analysis. Endogenous gapA protein and exogenously expressed (subcloned) GAPDH proteins were detected in E. coli BL21 but not for gapC. With the exception of gapC in E. coli, the various isoforms of GAPDH possessed enzymatic activity. Finally, sequence analysis revealed that the GAPDH proteins were 76% identical, with the exception of E. coli gapC. Taken together, our results indicate that GAPDH could be universally used as an internal control for the Western blot analysis of prokaryotic and eukaryotic samples.

  7. Evaluation of immunodominant proteins of Mycobacterium avium paratuberculosis cell wall by Western blot analysis.

    Science.gov (United States)

    Hashemi, Maryam; Madani, Rasool; Razmi, Nematollah

    2014-04-01

    Mycobacterium avium subspecies paratuberculosis (M. paratuberculosis) is a slow growing mycobactin, whose dependence on mycobacterial species is known to be the causative agent of Johne's disease (paratuberculosis) in all species of domestic ruminants worldwide. The organism is transmitted via close contact, ingestion, or transplacentally from mother to fetus and occurs commonly in grazing domestic animals. Johne's disease (JD) is characterized by gradual weight loss, decreased milk production, and diarrhea due to the chronic, progressive, granulomatous enteritis and lymphadenitis. The disease can cause serious economic damage to the dairy industry due to the loss of milk production and early culling of infected animals. In recent years, researchers have focused on the identification of a specific antigen of M. paratuberculosis to use in diagnosis test and preparation of effective vaccine. The goal of this study is evaluation of the immunodominant proteins of M. paratuberculosis cell wall. The amount of protein was determined with a Lowry assay (22.68 μg/100 μL). For production of polyclonal antibody against proteins of M. paratuberculosis cell wall, a New Zealand white rabbit was immunized with antigen and Freund's adjuvant. After immunization, the rabbit was bled to produce enriched serum. Antibodies were purified from serum with ion exchange chromatography. In the Ouchterlony test, the reactions between antigen and antibodies were seen in dilutions of one quarter for serum, one quarter for Ig, and one half for IgG by clear precipitation lines due to the well immunization of the rabbit. Electrophoresis and Western blot analysis were used and subsequently a sharp band appeared in nitrocellulose paper; these bands were about 25, 37, 50, 75, and 150 kDa molecular weight, which indicated immunodominant proteins.

  8. Cross-Reactions between Toxocara canis and Ascaris suum in the diagnosis of visceral larva migrans by western blotting technique

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    NUNES Cáris Maroni

    1997-01-01

    Full Text Available Visceral larva migrans (VLM is a clinical syndrome caused by infection of man by Toxocara spp, the common roundworm of dogs and cats. Tissue migration of larval stages causes illness specially in children. Because larvae are difficult to detect in tissues, diagnosis is mostly based on serology. After the introduction of the enzyme-linked immunosorbent assay (ELISA using the larval excretory-secretory antigen of T. canis (TES, the diagnosis specificity was greatly improved although cross-reactivity with other helminths are still being reported. In Brazil, diagnosis is routinely made after absorption of serum samples with Ascaris suum antigens, a nematode antigenicaly related with Ascaris lumbricoides which is a common intestinal nematode of children. In order to identify T. canis antigens that cross react to A. suum antigens we analyzed TES antigen by SDS-PAGE and Western blotting techniques. When we used serum samples from patients suspected of VLM and positive result by ELISA as well as a reference serum sample numerous bands were seen (molecular weight of 210-200 kDa, 116-97 kDa, 55-50 kDa and 35-29 kDa. Among these there is at least one band with molecular weight around 55-66 kDa that seem to be responsible for the cross-reactivity between T. canis e A. suum once it disappears when previous absorption of serum samples with A. suum antigens is performed

  9. Modification of T-cell antigenic properties of tetanus toxoid by SDS-PAGE separation. Implications for T-cell blotting

    DEFF Research Database (Denmark)

    Christensen, C B; Theander, T G

    1997-01-01

    Using Tetanus Toxoid (TT) as a model antigen the T-cell Blotting method was evaluated. Peripheral blood mononuclear cell (PBMC) cultures were stimulated by blotted nitrocellulose-bound TT or soluble TT. SDS-Poly-Acrylamide-Gel-Electrophoresis separated TT only induced proliferation in 20% of the ......Using Tetanus Toxoid (TT) as a model antigen the T-cell Blotting method was evaluated. Peripheral blood mononuclear cell (PBMC) cultures were stimulated by blotted nitrocellulose-bound TT or soluble TT. SDS-Poly-Acrylamide-Gel-Electrophoresis separated TT only induced proliferation in 20...... that SDS-PAGE alters the ability of TT to induce T-cell proliferation, possibly due to unpolymerized acrylamide binding to proteins during SDS-PAGE. The use of SDS-PAGE T-cell blotting in the screening for T-cell antigens must therefore be reconsidered. We suggest the use of SDS-Agarose Gel Electrophoresis...

  10. Lectin staining and Western blot data showing differential sialylation of nutrient-deprived cancer cells to sialic acid supplementation.

    Science.gov (United States)

    Badr, Haitham A; AlSadek, Dina M M; Mathew, Mohit P; Li, Chen-Zhong; Djansugurova, Leyla B; Yarema, Kevin J; Ahmed, Hafiz

    2015-12-01

    This report provides data that are specifically related to the differential sialylation of nutrient deprived breast cancer cells to sialic acid supplementation in support of the research article entitled, "Nutrient-deprived cancer cells preferentially use sialic acid to maintain cell surface glycosylation" [1]. Particularly, breast cancer cells, when supplemented with sialic acid under nutrient deprivation, display sialylated glycans at the cell surface, but non-malignant mammary cells show sialylated glycans intracellularly. The impact of sialic acid supplementation under nutrient deprivation was demonstrated by measuring levels of expression and sialylation of two markers, EGFR1 and MUC1. This Data in Brief article complements the main manuscript by providing detailed instructions and representative results for cell-level imaging and Western blot analyses of changes in sialylation during nutrient deprivation and sialic acid supplementation. These methods can be readily generalized for the study of many types of glycosylation and various glycoprotein markers through the appropriate selection of fluorescently-labeled lectins.

  11. Detection of Sleeping Beauty transposition in the genome of host cells by non-radioactive Southern blot analysis.

    Science.gov (United States)

    Aravalli, Rajagopal N; Park, Chang W; Steer, Clifford J

    2016-08-26

    The Sleeping Beauty transposon (SB-Tn) system is being used widely as a DNA vector for the delivery of therapeutic transgenes, as well as a tool for the insertional mutagenesis in animal models. In order to accurately assess the insertional potential and properties related to the integration of SB it is essential to determine the copy number of SB-Tn in the host genome. Recently developed SB100X transposase has demonstrated an integration rate that was much higher than the original SB10 and that of other versions of hyperactive SB transposases, such as HSB3 or HSB17. In this study, we have constructed a series of SB vectors carrying either a DsRed or a human β-globin transgene that was encompassed by cHS4 insulator elements, and containing the SB100X transposase gene outside the SB-Tn unit within the same vector in cis configuration. These SB-Tn constructs were introduced into the K-562 erythroid cell line, and their presence in the genomes of host cells was analyzed by Southern blot analysis using non-radioactive probes. Many copies of SB-Tn insertions were detected in host cells regardless of transgene sequences or the presence of cHS4 insulator elements. Interestingly, the size difference of 2.4 kb between insulated SB and non-insulated controls did not reflect the proportional difference in copy numbers of inserted SB-Tns. We then attempted methylation-sensitive Southern blots to assess the potential influence of cHS4 insulator elements on the epigenetic modification of SB-Tn. Our results indicated that SB100X was able to integrate at multiple sites with the number of SB-Tn copies larger than 6 kb in size. In addition, the non-radioactive Southern blot protocols developed here will be useful to detect integrated SB-Tn copies in any mammalian cell type.

  12. Lectin staining and Western blot data showing differential sialylation of nutrient-deprived cancer cells to sialic acid supplementation

    Directory of Open Access Journals (Sweden)

    Haitham A. Badr

    2015-12-01

    Full Text Available This report provides data that are specifically related to the differential sialylation of nutrient deprived breast cancer cells to sialic acid supplementation in support of the research article entitled, “Nutrient-deprived cancer cells preferentially use sialic acid to maintain cell surface glycosylation" [1]. Particularly, breast cancer cells, when supplemented with sialic acid under nutrient deprivation, display sialylated glycans at the cell surface, but non-malignant mammary cells show sialylated glycans intracellularly. The impact of sialic acid supplementation under nutrient deprivation was demonstrated by measuring levels of expression and sialylation of two markers, EGFR1 and MUC1. This Data in Brief article complements the main manuscript by providing detailed instructions and representative results for cell-level imaging and Western blot analyses of changes in sialylation during nutrient deprivation and sialic acid supplementation. These methods can be readily generalized for the study of many types of glycosylation and various glycoprotein markers through the appropriate selection of fluorescently-labeled lectins.

  13. Northern blotting analysis

    DEFF Research Database (Denmark)

    Josefsen, Knud; Nielsen, Henrik

    2011-01-01

    Northern blotting analysis is a classical method for analysis of the size and steady-state level of a specific RNA in a complex sample. In short, the RNA is size-fractionated by gel electrophoresis and transferred by blotting onto a membrane to which the RNA is covalently bound. Then, the membran...

  14. Utility of Schistosoma bovis Adult Worm Antigens for Diagnosis of Human Schistosomiasis by Enzyme-Linked Immunosorbent Assay and Electroimmunotransfer Blot Techniques

    Science.gov (United States)

    Pardo, J.; Carranza, C.; Turrientes, M. C.; Arellano, J. L. Pérez; Vélez, R. López; Ramajo, V.; Muro, A.

    2004-01-01

    Immunodiagnostic methods based on the detection of antibodies continue to be the most effective and practical methods for the diagnosis of imported schistosomiasis. Schistosoma bovis is a species whose final natural hosts are bovines, ovines, caprines, and small wild ruminants. Different studies have demonstrated the analogies existing between S. bovis and other Schistosoma species which affect humans. The objective of this work was to evaluate the utility of S. bovis adult worm antigens (AWA) for the diagnosis of imported human schistosomiasis by enzyme-linked immunosorbent assay (ELISA) and electroimmunotransfer blotting (EITB) techniques. By detecting eggs, the ELISA for S. bovis AWA was able to definitively detect imported cases with a sensitivity of 94%. The specificity of the ELISA for S. bovis AWA was 97%. There were no differences between the results of the S. bovis AWA ELISA for patients infected with Schistosoma mansoni and those infected with Schistosoma haematobium. The EITB technique showed bands of 85, 37, and 20 kDa, which are characteristic of infections with Schistosoma spp. Specific bands to indicate infection by different species of Schistosoma have not been detected. The combined use of the ELISA for S. bovis AWA and EITB increased the global sensitivity of the study to 97%. Our findings suggest that the ELISA for S. bovis AWA is a useful test for the immunodiagnosis of imported schistosomiasis and that EITB for detecting S. bovis AWA permits the confirmation of diagnosis when the ELISA for S. bovis AWA is positive. PMID:15539523

  15. Western blot analysis of a limited number of cells: a valuable adjunct to proteome analysis of paraffin wax-embedded, alcohol-fixed tissue after laser capture microdissection.

    Science.gov (United States)

    Martinet, Wim; Abbeloos, Vanessa; Van Acker, Nathalie; De Meyer, Guido R Y; Herman, Arnold G; Kockx, Mark M

    2004-03-01

    In recent years, laser capture microdissection (LCM) has been used successfully to obtain distinct populations of cells for subsequent molecular analysis. Because of the limited sample availability and the absence of in vitro amplification steps for proteins, the use of LCM for proteome analysis largely depends on highly sensitive protein detection methods. In this study, a western blot protocol was developed and validated for the detection of beta-actin and the moderately expressed cell death protein caspase-3 in small numbers of cells. Initially, cultured human U937 monocytes and whole sections of paraffin wax-embedded, alcohol-fixed human tonsils were used to optimize protein electrophoresis and western blotting conditions. High-performance NuPAGE Bis-Tris gels in combination with high-quality transfer membranes, optimized antibody concentrations, and a sensitive chemiluminescent substrate provided a strong signal for beta-actin with approximately 500 U937 cells. In the same way, procaspase-3 could be identified with approximately 1000 cells. Similar results were obtained with germinal centre cells that were procured from paraffin wax-embedded, alcohol-fixed human tonsils by LCM. Treatment of U937 cells with etoposide rapidly induced cell death and allowed the detection of active caspase-3 with approximately 2500 cells (0.8 pg of protein). The findings of this study suggest that western blotting is a valuable adjunct to proteome analysis of LCM procured cells.

  16. A Western blot-based investigation of the yeast secretory pathway designed for an intermediate-level undergraduate cell biology laboratory.

    Science.gov (United States)

    Hood-Degrenier, Jennifer K

    2008-01-01

    The movement of newly synthesized proteins through the endomembrane system of eukaryotic cells, often referred to generally as the secretory pathway, is a topic covered in most intermediate-level undergraduate cell biology courses. An article previously published in this journal described a laboratory exercise in which yeast mutants defective in two distinct steps of protein secretion were differentiated using a genetic reporter designed specifically to identify defects in the first step of the pathway, the insertion of proteins into the endoplasmic reticulum (Vallen, 2002). We have developed two versions of a Western blotting assay that serves as a second way of distinguishing the two secretory mutants, which we pair with the genetic assay in a 3-wk laboratory module. A quiz administered before and after students participated in the lab activities revealed significant postlab gains in their understanding of the secretory pathway and experimental techniques used to study it. A second survey administered at the end of the lab module assessed student perceptions of the efficacy of the lab activities; the results of this survey indicated that the experiments were successful in meeting a set of educational goals defined by the instructor.

  17. Whole cell entrapment techniques.

    Science.gov (United States)

    Trelles, Jorge A; Rivero, Cintia W

    2013-01-01

    Microbial whole cells are efficient, ecological, and low-cost catalysts that have been successfully applied in the pharmaceutical, environmental, and alimentary industries, among others. Microorganism immobilization is a good way to carry out the bioprocess under preparative conditions. The main advantages of this methodology lie in their high operational stability, easy upstream separation and bioprocess scale-up feasibility. Cell entrapment is the most widely used technique for whole cell immobilization. This technique-in which the cells are included within a rigid network-is porous enough to allow the diffusion of substrates and products, protects the selected microorganism from the reaction medium, and has high immobilization efficiency (100 % in most cases).

  18. A comparison of the immune parameters of dogs infected with visceral leishmaniasis using Western blot and neutralization techniques Comparação dos parâmetros imunológicos de cães infectados com leishmaniose visceral usando as técnicas de Western blot e neutralização

    Directory of Open Access Journals (Sweden)

    Yeda L. Nogueira

    2007-12-01

    Full Text Available The Western blot technique was used to demonstrate the presence of antibodies in the blood of dogs that presented canine visceral leishmaniasis. This technique was used against some specific molecules present in the lysate of the promastigote form of Leshmania chagasi.Through the association of the results of the Western blot technique with the morphological alterations seen as a result of the serum neutralization technique performed in McCoy cells (which mimetizes the macrophage it was possible to observe the role of some molecules of great relevance in determining the disease in symptomatic dogs as well as that of some other molecules associated with asymptomatic infected dogs that may become transmitters as well as differentiating them as asymptomatic resistant dogs. In the sera analyses carried out during the immunobloting a variation of 9 to 27 immunoreacting bands was observed, which were then compared using Dice's similarity coefficient. In the dendrogram constructed on the basis of the coefficient, 50% similarity was observed among the total number of reagent bands with the promastigote lysate, thus creating five groups. The main difference observed related to the clinical condition of the dogs: symptomatic and asymptomatic dogs were found in separate groups. The asymptomatic group of dogs was distributed in two different places in the dendrogram because they presented two different behavior patterns regarding the cellular morphology in the serum neutralization reaction: the presence or absence of cellular lysis. According to this analysis it is possible to evaluate the immune status and associate it with specific markers observed in the reaction found in the Western blot strips.A técnica de Western blot foi utilizada para demonstrar a presença de anticorpos do soro de cães, que apresentavam leishmaniose visceral canina, contra algumas moléculas específicas no lisado da forma promastigota de Leshmania chagasi.Através da associa

  19. Northern blotting analysis

    DEFF Research Database (Denmark)

    Josefsen, Knud; Nielsen, Henrik

    2011-01-01

    is analysed by hybridization to one or more specific probes that are labelled for subsequent detection. Northern blotting is relatively simple to perform, inexpensive, and not plagued by artefacts. Recent developments of hybridization membranes and buffers have resulted in increased sensitivity closing...

  20. Lectin staining and Western blot data showing differential sialylation of nutrient-deprived cancer cells to sialic acid supplementation

    OpenAIRE

    Badr, Haitham A.; Dina M. M. AlSadek; Mohit P. Mathew; Chen-Zhong Li; Djansugurova, Leyla B.; Yarema, Kevin J.; Hafiz Ahmed

    2015-01-01

    This report provides data that are specifically related to the differential sialylation of nutrient deprived breast cancer cells to sialic acid supplementation in support of the research article entitled, “Nutrient-deprived cancer cells preferentially use sialic acid to maintain cell surface glycosylation" [1]. Particularly, breast cancer cells, when supplemented with sialic acid under nutrient deprivation, display sialylated glycans at the cell surface, but non-malignant mammary cells show s...

  1. Diamond Anvil Cell Techniques

    Science.gov (United States)

    Piermarini, Gasper J.

    It has often been said that scientific advances are made either in a dramatic and revolutionary way, or, as in the case of the diamond anvil cell (DAC), in a slow and evolutionary manner over a period of several years. For more than 2 decades, commencing in 1958, the DAC developed stepwise from a rather crude qualitative instrument to the sophisticated quantitative research tool it is today, capable of routinely producing sustained static pressures in the multi-megabar range and readily adaptable to numerous scientific measurement techniques because of its optical accessibility, miniature size, and portability.

  2. Studying protein-protein interactions via blot overlay/far western blot.

    Science.gov (United States)

    Hall, Randy A

    2015-01-01

    Blot overlay is a useful method for studying protein-protein interactions. This technique involves fractionating proteins on SDS-PAGE, blotting to nitrocellulose or PVDF membrane, and then incubating with a probe of interest. The probe is typically a protein that is radiolabeled, biotinylated, or simply visualized with a specific antibody. When the probe is visualized via antibody detection, this technique is often referred to as "Far Western blot." Many different kinds of protein-protein interactions can be studied via blot overlay, and the method is applicable to screens for unknown protein-protein interactions as well as to the detailed characterization of known interactions.

  3. Genotypic analysis of cutaneous T-cell lymphoma: a comparative study of Southern blot analysis with polymerase chain reaction amplification of the T-cell receptor-gamma gene.

    Science.gov (United States)

    Curcó, N; Servitje, O; Llucià, M; Bertran, J; Limón, A; Carmona, M; Romagosa, V; Peyrí, J

    1997-11-01

    The diagnosis of early cutaneous T-cell lymphoma (CTCL) is a difficult point in dermatology. Recently, Southern blot analysis (SBA) and polymerase chain reaction (PCR) have been used to detect clonality in initial lesions in which clinical and histological findings are unspecific. Forty-one samples from 25 patients with CTCL were investigated for the presence of T-cell receptor-gamma gene rearrangement using a nested PCR technique and analysed by polyacrylamide gel electrophoresis (PAGE). Conventional SBA was also performed on 28 samples from 20 of these patients. In addition, 20 samples corresponding to patients with large plaque parapsoriasis (LPP), cutaneous B-cell lymphoma (CBCL) and eczema were analysed by PCR in the same way as were the CTCL specimens. Most of the CTCL specimens (81%) showed clonality on PCR analysis. Among patients with mycosis fungoides, 71% of initial patch lesions and 100% of plaques and tumours showed clonal disease. Clonality could be detected in three of four histologically negative post-treatment lesions. Clonal rearrangement was detected in one of three patients with LPP and in three of 10 patients with CBCL. None of the samples corresponding to patients with eczema showed positive results. SBA was significantly less sensitive than PCR in detecting clonality in CTCL patients (42% among early disease and 60% among advanced cases). The results indicate that this PCR/PAGE technique is a reliable and useful method for the detection of clonality in early skin lesions of CTCL patients and probably in the identification of silent extracutaneous involvement.

  4. Cell Phone Detection Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Pratt, Richard M.; Bunch, Kyle J.; Puzycki, David J.; Slaugh, Ryan W.; Good, Morris S.; McMakin, Douglas L.

    2007-10-01

    A team composed of Rick Pratt, Dave Puczyki, Kyle Bunch, Ryan Slaugh, Morris Good, and Doug McMakin teamed together to attempt to exploit cellular telephone features and detect if a person was carrying a cellular telephone into a Limited Area. The cell phone’s electromagnetic properties were measured, analyzed, and tested in over 10 different ways to determine if an exploitable signature exists. The method that appears to have the most potential for success without adding an external tag is to measure the RF spectrum, not in the cell phone band, but between 240 and 400MHz. Figures 1- 7 show the detected signal levels from cell phones from three different manufacturers.

  5. TLC-Blot (Far-Eastern Blot) and Its Application to Functional Lipidomics.

    Science.gov (United States)

    Taki, Takao

    2015-01-01

    A simple method for transfer of lipids-including phospholipids, glycolipids, and neutral lipids-from a high performance thin layer chromatography (HPTLC) plate to a polyvinylidene difluoride (PVDF) membrane, TLC-Blot (Far-Eastern Blot), and its biochemical applications are presented. This chapter presents the conventional procedures for separating lipid from tissue samples, cultured cells, and serum and the subsequent development of TLC. Individual lipids separated on an HPTLC plate can be transferred to the PVDF membrane quantitatively and also isolated from the lipid-blotted membrane by a one-step purification procedure. Immunodetection with monoclonal antibodies and treatment with lipid-metabolizing enzymes on the lipid-blotted membrane are possible. The method for identification of individual lipids transferred on the PVDF membrane using matrix-assisted laser desorption/ionization quadrupole ion trap time-of-flight mass spectrometry (TLC-Blot/MALDI-TOF MS) is shown as a functional lipidomics application.

  6. Selected Reaction Monitoring (SRM) frente a Western Blot

    OpenAIRE

    Heredia Ponce, Zahira Maria; Urbano Gámez, Jose Alberto

    2016-01-01

    We propose the SRM technology as a complementary method to the Western Blot for the detection and quantification of proteins in a sample. The technique Western Blot has its own limitations: i) only a protein-of-choice is detected, ignoring any non-relevant proteins, ii) the sensitivity of the technique depends on the specificity of the antibody and iii) Western Blot is expensive and time-consuming. The advantages of SRM with respect Western Blot are remarkable: i) you can detect up to h...

  7. Automated design of genomic Southern blot probes

    Directory of Open Access Journals (Sweden)

    Komiyama Noboru H

    2010-01-01

    Full Text Available Abstract Background Sothern blotting is a DNA analysis technique that has found widespread application in molecular biology. It has been used for gene discovery and mapping and has diagnostic and forensic applications, including mutation detection in patient samples and DNA fingerprinting in criminal investigations. Southern blotting has been employed as the definitive method for detecting transgene integration, and successful homologous recombination in gene targeting experiments. The technique employs a labeled DNA probe to detect a specific DNA sequence in a complex DNA sample that has been separated by restriction-digest and gel electrophoresis. Critically for the technique to succeed the probe must be unique to the target locus so as not to cross-hybridize to other endogenous DNA within the sample. Investigators routinely employ a manual approach to probe design. A genome browser is used to extract DNA sequence from the locus of interest, which is searched against the target genome using a BLAST-like tool. Ideally a single perfect match is obtained to the target, with little cross-reactivity caused by homologous DNA sequence present in the genome and/or repetitive and low-complexity elements in the candidate probe. This is a labor intensive process often requiring several attempts to find a suitable probe for laboratory testing. Results We have written an informatic pipeline to automatically design genomic Sothern blot probes that specifically attempts to optimize the resultant probe, employing a brute-force strategy of generating many candidate probes of acceptable length in the user-specified design window, searching all against the target genome, then scoring and ranking the candidates by uniqueness and repetitive DNA element content. Using these in silico measures we can automatically design probes that we predict to perform as well, or better, than our previous manual designs, while considerably reducing design time. We went on to

  8. Fast and Simple micro-RNA Northern Blots

    Directory of Open Access Journals (Sweden)

    Nham Tran

    2009-01-01

    Full Text Available RNA northern blots provide robust measurements of gene expression. The simple northern blot technique described in this report has been optimised to provide rapid, reproducible detection and analysis of mature and precursor forms of microRNAs. This protocol economises on the use of commercially available components and secondly reduces the hybridisation step to 2 hours.

  9. Comparison of Linear Array and Line Blot Assay for Detection of Human Papillomavirus and Diagnosis of Cervical Precancer and Cancer in the Atypical Squamous Cell of Undetermined Significance and Low-Grade Squamous Intraepithelial Lesion Triage Study▿

    OpenAIRE

    Castle, Philip E.; Gravitt, Patti E.; Solomon, Diane; Wheeler, Cosette M.; Schiffman, Mark

    2007-01-01

    We evaluated Linear Array (LA), a newly commercialized PGMY09/11 L1 consensus primer PCR test that detects 37 human papillomavirus (HPV) genotypes by reverse line blot hybridization, for the detection of individual HPV genotypes and carcinogenic HPV and its clinical performance for detecting 2-year cumulative cervical precancer and cancer using archived specimens from the Atypical Squamous Cell of Undetermined Significance (ASCUS) and Low-Grade Squamous Intraepithelial Lesion Triage Study. LA...

  10. A Western Blot-based Investigation of the Yeast Secretory Pathway Designed for an Intermediate-Level Undergraduate Cell Biology Laboratory

    Science.gov (United States)

    Hood-DeGrenier, Jennifer K.

    2008-01-01

    The movement of newly synthesized proteins through the endomembrane system of eukaryotic cells, often referred to generally as the secretory pathway, is a topic covered in most intermediate-level undergraduate cell biology courses. An article previously published in this journal described a laboratory exercise in which yeast mutants defective in…

  11. The Design of a Quantitative Western Blot Experiment

    Directory of Open Access Journals (Sweden)

    Sean C. Taylor

    2014-01-01

    Full Text Available Western blotting is a technique that has been in practice for more than three decades that began as a means of detecting a protein target in a complex sample. Although there have been significant advances in both the imaging and reagent technologies to improve sensitivity, dynamic range of detection, and the applicability of multiplexed target detection, the basic technique has remained essentially unchanged. In the past, western blotting was used simply to detect a specific target protein in a complex mixture, but now journal editors and reviewers are requesting the quantitative interpretation of western blot data in terms of fold changes in protein expression between samples. The calculations are based on the differential densitometry of the associated chemiluminescent and/or fluorescent signals from the blots and this now requires a fundamental shift in the experimental methodology, acquisition, and interpretation of the data. We have recently published an updated approach to produce quantitative densitometric data from western blots (Taylor et al., 2013 and here we summarize the complete western blot workflow with a focus on sample preparation and data analysis for quantitative western blotting.

  12. The line blot assay: problems with titrating first and second antibodies for Western blot and immunohistochemistry assays?

    Science.gov (United States)

    Rojas-Espinosa, O; Silva-Miranda, M; Wek-Rodriguez, K; Arce-Paredes, P

    2006-01-01

    We describe a technique designed to assess the optimal dilution of primary and secondary antibodies, to be used in Western blot, dot blot, the multi-antigen print immunoassay (MAPIA) and immunohistochemistry assays. The method that we call "line blot" is not an alternative but a practical, complementary tool for the above techniques that assures definitive results are obtained from single assays, so there is no need to repeat the assay. As with most immunoenzymatic assays, the line blot assay is very sensitive, allowing the detection of absolute amounts of antigen as low as 2.5 ng in the 0.5 cm-long segment line (see Results), depending on the strength of the secondary, enzyme-labelled antibody.

  13. Cell culture techniques in honey bee research

    Science.gov (United States)

    Cell culture techniques are indispensable in most if not all life science disciplines to date. Wherever cell culture models are lacking scientific development is hampered. Unfortunately this has been and still is the case in honey bee research because permanent honey bee cell lines have not yet been...

  14. Uso da técnica de Southern Blot/Hibridização associada à reação em cadeia da polimerase para aumentar a sensibilidade no diagnóstico das infecções por hemoplasmas em gatos domésticos: Use of Southern Blot/Hybridization technique associated to polymerase chain reaction to improve the sensitivity in the diagnosis of hemoplasma infections in domestic cats

    Directory of Open Access Journals (Sweden)

    Daniel B. Macieira

    2009-12-01

    Full Text Available O objetivo deste trabalho foi verificar se a técnica de Southern Blot/Hibridização (SB em associação à reação de polimerização em cadeia (PCR aumenta a sensibilidade na detecção de DNA de hemoplasmas em gatos domésticos (Felis catus. O sangue total foi coletado em tubos contendo o anticoagulante ácido etilenodiamino tetra-acético, o DNA extraído a partir de 149 animais e a PCR realizada com o uso de sequências iniciadoras espécie-específicas, para amplificar subunidade 16S do RNA ribossomal de Mycoplasma haemofelis e 'Candidatus M. haemominutum' dessas amostras. Para a hibridização, foram utilizadas sondas específicas quimicamente marcadas, e os resultados visualizados por meio da adição de substrato quimiluminescente seguida de autoradiografia. Dezoito (12,1% das 149 amostras testadas apresentaram resultado PCR-positivo para o DNA de hemoplasmas. A técnica de SB mostrou que 24/149 (16,1% amostras apresentaram resultado positivo para hemoplasmas, confirmando os 18 resultados PCR-positivos, além de revelar seis outros adicionais (p The aim of this study was to determine whether Southern Blot/Hybridization (SB associated to Polymerase Chain Reaction (PCR improves the sensitivity in the detection of hemoplasma DNA in domestic cats (Felis catus. Whole blood was collected in tubes containing the anticoagulant ethylenediamine tetra-acetic acid and DNA extracted from 149 animals. PCR was performed using species specific primers to amplify the 16S ribosomal RNA subunit of Mycoplasma haemofelis and 'Candidatus M. haemominutum' from these samples. Hybridization was performed using a 16S rDNA probes chemically labeled and the results were visualized using a chemiluminescent substrate addition followed by autoradiography. Eighteen (12.1% of the 149 tested samples had a positive PCR result for hemoplasma species DNA. SB/hybridization technique showed that 24/149 (16.1% samples were positive for hemoplasmas, confirming the 18 PCR

  15. [Stem cells and tissue engineering techniques].

    Science.gov (United States)

    Sica, Gigliola

    2013-01-01

    The therapeutic use of stem cells and tissue engineering techniques are emerging in urology. Here, stem cell types, their differentiating potential and fundamental characteristics are illustrated. The cancer stem cell hypothesis is reported with reference to the role played by stem cells in the origin, development and progression of neoplastic lesions. In addition, recent reports of results obtained with stem cells alone or seeded in scaffolds to overcome problems of damaged urinary tract tissue are summarized. Among others, the application of these biotechnologies in urinary bladder, and urethra are delineated. Nevertheless, apart from the ethical concerns raised from the use of embryonic stem cells, a lot of questions need to be solved concerning the biology of stem cells before their widespread use in clinical trials. Further investigation is also required in tissue engineering utilizing animal models.

  16. Solar Cell Calibration and Measurement Techniques

    Science.gov (United States)

    Bailey, Sheila; Brinker, Dave; Curtis, Henry; Jenkins, Phillip; Scheiman, Dave

    2004-01-01

    The increasing complexity of space solar cells and the increasing international markets for both cells and arrays has resulted in workshops jointly sponsored by NASDA, ESA and NASA. These workshops are designed to obtain international agreement on standardized values for the AMO spectrum and constant, recommend laboratory measurement practices and establish a set of protocols for international comparison of laboratory measurements. A working draft of an ISO standard, WD15387, "Requirements for Measurement and Calibration Procedures for Space Solar Cells" was discussed with a focus on the scope of the document, a definition of primary standard cell, and required error analysis for all measurement techniques. Working groups addressed the issues of Air Mass Zero (AMO) solar constant and spectrum, laboratory measurement techniques, and te international round robin methodology. A summary is presented of the current state of each area and the formulation of the ISO document.

  17. Comparison of linear array and line blot assay for detection of human papillomavirus and diagnosis of cervical precancer and cancer in the atypical squamous cell of undetermined significance and low-grade squamous intraepithelial lesion triage study.

    Science.gov (United States)

    Castle, Philip E; Gravitt, Patti E; Solomon, Diane; Wheeler, Cosette M; Schiffman, Mark

    2008-01-01

    We evaluated Linear Array (LA), a newly commercialized PGMY09/11 L1 consensus primer PCR test that detects 37 human papillomavirus (HPV) genotypes by reverse line blot hybridization, for the detection of individual HPV genotypes and carcinogenic HPV and its clinical performance for detecting 2-year cumulative cervical precancer and cancer using archived specimens from the Atypical Squamous Cell of Undetermined Significance (ASCUS) and Low-Grade Squamous Intraepithelial Lesion Triage Study. LA testing was conducted on enrollment specimens from women referred because of an ASCUS Pap test. To gauge the performance of the new test, the results were compared to those of its prototype predecessor assay, Line Blot Assay (LBA), restricted to paired results (n = 3,335). LA testing was done masked to LBA results and clinical outcomes. The results of LA and LBA testing were compared for detection of carcinogenic HPV and clinical outcomes of cervical precancer and cancer. Overall, 50% and 55% of the women tested positive for carcinogenic HPV by LBA and LA, respectively (P < 0.0001). The percent agreement for carcinogenic HPV detection was 88%, percent positive agreement was 80%, and kappa was 0.76 for detection of carcinogenic HPV by the two assays. There was a significant increase in detection by LA for most of the 37 HPV genotypes targeted by both assays, including for 13 of 14 carcinogenic HPV genotypes. LA detected more multiple-genotype infections for all HPV genotypes among HPV-positive women (P < 0.0001) and for carcinogenic HPV genotypes among carcinogenic-HPV-positive women (P < 0.0001). LA was more sensitive (92.3% versus 87.1%; P = 0.003) and less specific (48.2% versus 54.0%; P < 0.0001) than LBA for 2-year cumulative cervical precancer and cancer as diagnosed by the Pathology Quality Control Group. In conclusion, we found LA to be a promising assay for the detection of HPV genotypes and carcinogenic HPV, and it may be clinically useful for the detection of

  18. Comparison of Linear Array and Line Blot Assay for Detection of Human Papillomavirus and Diagnosis of Cervical Precancer and Cancer in the Atypical Squamous Cell of Undetermined Significance and Low-Grade Squamous Intraepithelial Lesion Triage Study▿

    Science.gov (United States)

    Castle, Philip E.; Gravitt, Patti E.; Solomon, Diane; Wheeler, Cosette M.; Schiffman, Mark

    2008-01-01

    We evaluated Linear Array (LA), a newly commercialized PGMY09/11 L1 consensus primer PCR test that detects 37 human papillomavirus (HPV) genotypes by reverse line blot hybridization, for the detection of individual HPV genotypes and carcinogenic HPV and its clinical performance for detecting 2-year cumulative cervical precancer and cancer using archived specimens from the Atypical Squamous Cell of Undetermined Significance (ASCUS) and Low-Grade Squamous Intraepithelial Lesion Triage Study. LA testing was conducted on enrollment specimens from women referred because of an ASCUS Pap test. To gauge the performance of the new test, the results were compared to those of its prototype predecessor assay, Line Blot Assay (LBA), restricted to paired results (n = 3,335). LA testing was done masked to LBA results and clinical outcomes. The results of LA and LBA testing were compared for detection of carcinogenic HPV and clinical outcomes of cervical precancer and cancer. Overall, 50% and 55% of the women tested positive for carcinogenic HPV by LBA and LA, respectively (P < 0.0001). The percent agreement for carcinogenic HPV detection was 88%, percent positive agreement was 80%, and kappa was 0.76 for detection of carcinogenic HPV by the two assays. There was a significant increase in detection by LA for most of the 37 HPV genotypes targeted by both assays, including for 13 of 14 carcinogenic HPV genotypes. LA detected more multiple-genotype infections for all HPV genotypes among HPV-positive women (P < 0.0001) and for carcinogenic HPV genotypes among carcinogenic-HPV-positive women (P < 0.0001). LA was more sensitive (92.3% versus 87.1%; P = 0.003) and less specific (48.2% versus 54.0%; P < 0.0001) than LBA for 2-year cumulative cervical precancer and cancer as diagnosed by the Pathology Quality Control Group. In conclusion, we found LA to be a promising assay for the detection of HPV genotypes and carcinogenic HPV, and it may be clinically useful for the detection of

  19. Optical Management Techniques for Organic Solar Cells

    CERN Document Server

    Rajagopal, Adharsh

    2016-01-01

    In this thesis, two different optical management techniques for organics based solar cells are explored. The first part is focused on the development of a textured rear reflector for OPVs. The use of textured reflector (TR) facilitates an increase in the optical path length along with light trapping within the active layer. TR was fabricated through a relatively simpler technique by depositing metal films over a microlens array (MLA). Zinc oxide nanoparticles were used to minimize the shadowing effect. Using TR, enhancements in short-circuit current density and power conversion efficiencies up to 10-25% were demonstrated for a polymer based organic solar cell. The second part is focused on improving the effectiveness of MLA incorporation in OPVs. The increase in path length achieved using MLA can be improved by increasing the refractive index of MLA and incorporating MLA directly on the transparent electrode instead of glass substrate. This approach could avoid the optical losses occurring at the interface be...

  20. Current techniques for visualizing RNA in cells

    Science.gov (United States)

    Mannack, Lilith V.J.C.; Eising, Sebastian; Rentmeister, Andrea

    2016-01-01

    Labeling RNA is of utmost interest, particularly in living cells, and thus RNA imaging is an emerging field. There are numerous methods relying on different concepts ranging from hybridization-based probes, over RNA-binding proteins to chemo-enzymatic modification of RNA. These methods have different benefits and limitations. This review aims to outline the current state-of-the-art techniques and point out their benefits and limitations. PMID:27158473

  1. Immunochemische detectiemethoden na western blotting van cytochroom P-450 iso-enzymen

    NARCIS (Netherlands)

    Laan CA; Jansen EHJM

    1992-01-01

    In this report a number of staining techniques on Western blots have been compared with respect to sensitivity, background staining, practical applicability and cost aspects. After electrophoresis of a rat microsomal liver sample followed by blotting, an incubation was performed of a primary antibo

  2. Zinc Blotting Assay for Detection of Zinc-Binding Prolamin in Barley (Hordeum vulgare) Grain

    DEFF Research Database (Denmark)

    Uddin, Mohammad Nasir; Langkilde, Ane; Vincze, Éva

    2014-01-01

    In plants, zinc is commonly found bound to proteins. In barley (Hordeum vulgare), major storage proteins are alcohol-soluble prolamins known as hordeins, and some of them have the potential to bind or store zinc. 65Zn overlay and blotting techniques have been widely used for detecting zinc......-binding protein. However, to our knowledge so far this zinc blotting assay has never been applied to detect a prolamin fraction in barley grains. A radioactive zinc (65ZnCl2) blotting technique was optimized to detect zinc-binding prolamins, followed by development of an easy-to-follow nonradioactive colorimetric...... zinc blotting method with a zinc-sensing dye, dithizone. Hordeins were extracted from mature barley grain, separated by SDS-PAGE, blotted on a membrane, renatured, overlaid, and probed with zinc; subsequently, zinc-binding specificity of certain proteins was detected either by autoradiography or color...

  3. The study of multiple RT-PCR-based reverse dot blot hybridization technique for detecting influenza viruses%多重RT-PCR结合反向杂交技术检测多种流感病毒方法的研究

    Institute of Scientific and Technical Information of China (English)

    杨亮; 钱永华; 曾毅; 张晓梅; 张晓光; 马晶; 王敏; 温乐英; 王大燕; 白天; 舒跃龙

    2010-01-01

    目的 建立一种基于多重RT-PCR结合反向斑点杂交技术的多种流感病毒核酸快速检测方法.方法 对5种亚型流感病毒的HA基因序列进行比对分析,选择合适的保守区域设计引物序列,并在扩增产物序列内部选择高变区设计探针序列.首先,使用生物素标记的引物扩增出同样带标记的PCR产物;然后,产物与膜上的探针杂交,通过生物素-亲和素反应,最后以斑点显色的方式来检测和鉴别不同亚型的流感病毒.实验中还通过摸索不同的引物浓度和探针浓度来优化反应条件.结果 成功建立了一种基于多重RT-PCR结合反向斑点杂交技术的检测方法,该方法能够成功检测和鉴别5种不同亚型的流感病毒,检测灵敏度比传统的RT-PCR方法高100~1000倍.结论 成功建立了一种可高通量快速检测多种流感病毒的多重RT-PCR结合反向斑点杂交技术的检测方法.%Objective To establish a multiplex RT-PCR-based reverse dot blot hybridization technique to detect influenza viruses. Methods Obtain the HA nucleotide sequences of seasonal influenza H1 N1, seasonal influenza H3N2, influenza H1 N1 and human avian influenza H5 N1 from GenBank. Design primers in conservative district and probes t in high variable region respectively, after analyzing the HA nucleotide sequences of influenza virus through the Vector NTI 9.0. Establish and optimize multiple RT-PCR system by comparing amplification efficiency and specificity at different primer concentrations. Establish the reverse dot hybridization system after optimizing the concentration of probes. To compare the sensitivity and specificity of this technique and the general RT-PCR Method through extracting the viral RNA of the mentioned influenza virus which are to be the reference substance. Results Successfully establish a multiplex RT-PCR-based reverse dot blot hybridization technique for detecting influenza viruses. This technique is 100-1000 times more

  4. Recombinant antigen-based immuno-slot blot method for serodiagnosis of syphilis

    Directory of Open Access Journals (Sweden)

    N.S. Sato

    2004-07-01

    Full Text Available Three recombinant antigens of Treponema pallidum Nichols strain were fused with GST, cloned and expressed in Escherichia coli, resulting in high levels of GST-rTp47 and GST-rTp17 expression, and supplementation with arginine tRNA for the AGR codon was needed to obtain GST-rTp15 overexpression. Purified fusion protein yields were 1.9, 1.7 and 5.3 mg/l of cell culture for GST-rTp47, GST-rTp17 and GST-rTp15, respectively. The identities of the antigens obtained were confirmed by automated DNA sequencing using ABI Prism 310 and peptide mapping by Finningan LC/MS. These recombinant antigens were evaluated by immuno-slot blot techniques applied to 137 serum samples from patients with a clinical and laboratory diagnosis of syphilis (61 samples, from healthy blood donors (50 samples, individuals with sexually transmitted disease other than syphilis (3 samples, and from individuals with other spirochetal diseases such as Lyme disease (20 samples and leptospirosis (3 samples. The assay had sensitivity of 95.1% (95% CI, 86.1 to 98.7% and a specificity of 94.7% (95% CI, 87.0 to 98.7%; a stronger reactivity was observed with fraction rTp17. The immunoreactivity results showed that fusion recombinant antigens based-immuno-slot blot techniques are suitable for use in diagnostic assays for syphilis.

  5. An Introductory Undergraduate Course Covering Animal Cell Culture Techniques

    Science.gov (United States)

    Mozdziak, Paul E.; Petitte, James N.; Carson, Susan D.

    2004-01-01

    Animal cell culture is a core laboratory technique in many molecular biology, developmental biology, and biotechnology laboratories. Cell culture is a relatively old technique that has been sparingly taught at the undergraduate level. The traditional methodology for acquiring cell culture training has been through trial and error, instruction when…

  6. Laser-based direct-write techniques for cell printing.

    Science.gov (United States)

    Schiele, Nathan R; Corr, David T; Huang, Yong; Raof, Nurazhani Abdul; Xie, Yubing; Chrisey, Douglas B

    2010-09-01

    Fabrication of cellular constructs with spatial control of cell location (+/-5 microm) is essential to the advancement of a wide range of applications including tissue engineering, stem cell and cancer research. Precise cell placement, especially of multiple cell types in co- or multi-cultures and in three dimensions, can enable research possibilities otherwise impossible, such as the cell-by-cell assembly of complex cellular constructs. Laser-based direct writing, a printing technique first utilized in electronics applications, has been adapted to transfer living cells and other biological materials (e.g., enzymes, proteins and bioceramics). Many different cell types have been printed using laser-based direct writing, and this technique offers significant improvements when compared to conventional cell patterning techniques. The predominance of work to date has not been in application of the technique, but rather focused on demonstrating the ability of direct writing to pattern living cells, in a spatially precise manner, while maintaining cellular viability. This paper reviews laser-based additive direct-write techniques for cell printing, and the various cell types successfully laser direct-written that have applications in tissue engineering, stem cell and cancer research are highlighted. A particular focus is paid to process dynamics modeling and process-induced cell injury during laser-based cell direct writing.

  7. Laser-based direct-write techniques for cell printing

    Energy Technology Data Exchange (ETDEWEB)

    Schiele, Nathan R; Corr, David T [Biomedical Engineering Department, Rensselaer Polytechnic Institute, Troy, NY (United States); Huang Yong [Department of Mechanical Engineering, Clemson University, Clemson, SC (United States); Raof, Nurazhani Abdul; Xie Yubing [College of Nanoscale Science and Engineering, University at Albany, SUNY, Albany, NY (United States); Chrisey, Douglas B, E-mail: schien@rpi.ed, E-mail: chrisd@rpi.ed [Material Science and Engineering Department, Rensselaer Polytechnic Institute, Troy, NY (United States)

    2010-09-15

    Fabrication of cellular constructs with spatial control of cell location ({+-}5 {mu}m) is essential to the advancement of a wide range of applications including tissue engineering, stem cell and cancer research. Precise cell placement, especially of multiple cell types in co- or multi-cultures and in three dimensions, can enable research possibilities otherwise impossible, such as the cell-by-cell assembly of complex cellular constructs. Laser-based direct writing, a printing technique first utilized in electronics applications, has been adapted to transfer living cells and other biological materials (e.g., enzymes, proteins and bioceramics). Many different cell types have been printed using laser-based direct writing, and this technique offers significant improvements when compared to conventional cell patterning techniques. The predominance of work to date has not been in application of the technique, but rather focused on demonstrating the ability of direct writing to pattern living cells, in a spatially precise manner, while maintaining cellular viability. This paper reviews laser-based additive direct-write techniques for cell printing, and the various cell types successfully laser direct-written that have applications in tissue engineering, stem cell and cancer research are highlighted. A particular focus is paid to process dynamics modeling and process-induced cell injury during laser-based cell direct writing. (topical review)

  8. Antibody performance in western blot applications is context-dependent.

    Science.gov (United States)

    Algenäs, Cajsa; Agaton, Charlotta; Fagerberg, Linn; Asplund, Anna; Björling, Lisa; Björling, Erik; Kampf, Caroline; Lundberg, Emma; Nilsson, Peter; Persson, Anja; Wester, Kenneth; Pontén, Fredrik; Wernérus, Henrik; Uhlén, Mathias; Ottosson Takanen, Jenny; Hober, Sophia

    2014-03-01

    An important concern for the use of antibodies in various applications, such as western blot (WB) or immunohistochemistry (IHC), is specificity. This calls for systematic validations using well-designed conditions. Here, we have analyzed 13 000 antibodies using western blot with lysates from human cell lines, tissues, and plasma. Standardized stratification showed that 45% of the antibodies yielded supportive staining, and the rest either no staining (12%) or protein bands of wrong size (43%). A comparative study of WB and IHC showed that the performance of antibodies is application-specific, although a correlation between no WB staining and weak IHC staining could be seen. To investigate the influence of protein abundance on the apparent specificity of the antibody, new WB analyses were performed for 1369 genes that gave unsupportive WBs in the initial screening using cell lysates with overexpressed full-length proteins. Then, more than 82% of the antibodies yielded a specific band corresponding to the full-length protein. Hence, the vast majority of the antibodies (90%) used in this study specifically recognize the target protein when present at sufficiently high levels. This demonstrates the context- and application-dependence of antibody validation and emphasizes that caution is needed when annotating binding reagents as specific or cross-reactive. WB is one of the most commonly used methods for validation of antibodies. Our data implicate that solely using one platform for antibody validation might give misleading information and therefore at least one additional method should be used to verify the achieved data.

  9. A Streamlined Western Blot Exercise: An Efficient and Greener Approach in the Laboratory Classroom

    Science.gov (United States)

    Ness, Traci L.; Robinson, Rebekah L.; Mojadedi, Wais; Peavy, Lydia; Weiland, Mitch H.

    2015-01-01

    SDS-PAGE and western blotting are two commonly taught protein detection techniques in biochemistry and molecular biology laboratory classrooms. A pitfall associated with incorporating these techniques into the laboratory is the significant wait times that do not allow students to obtain timely results. The waiting associated with SDS-PAGE comes…

  10. Isolation of cellular lipid droplets: two purification techniques starting from yeast cells and human placentas.

    Science.gov (United States)

    Mannik, Jaana; Meyers, Alex; Dalhaimer, Paul

    2014-04-01

    Lipid droplets are dynamic organelles that can be found in most eukaryotic and certain prokaryotic cells. Structurally, the droplets consist of a core of neutral lipids surrounded by a phospholipid monolayer. One of the most useful techniques in determining the cellular roles of droplets has been proteomic identification of bound proteins, which can be isolated along with the droplets. Here, two methods are described to isolate lipid droplets and their bound proteins from two wide-ranging eukaryotes: fission yeast and human placental villous cells. Although both techniques have differences, the main method-- density gradient centrifugation--is shared by both preparations. This shows the wide applicability of the presented droplet isolation techniques. In the first protocol, yeast cells are converted into spheroplasts by enzymatic digestion of their cell walls. The resulting spheroplasts are then gently lysed in a loose-fitting homogenizer. Ficoll is added to the lysate to provide a density gradient, and the mixture is centrifuged three times. After the first spin, the lipid droplets are localized to the white-colored floating layer of the centrifuge tubes along with the endoplasmic reticulum (ER), the plasma membrane, and vacuoles. Two subsequent spins are used to remove these other three organelles. The result is a layer that has only droplets and bound proteins. In the second protocol, placental villous cells are isolated from human term placentas by enzymatic digestion with trypsin and DNase I. The cells are homogenized in a loose-fitting homogenizer. Low-speed and medium-speed centrifugation steps are used to remove unbroken cells, cellular debris, nuclei, and mitochondria. Sucrose is added to the homogenate to provide a density gradient and the mixture is centrifuged to separate the lipid droplets from the other cellular fractions. The purity of the lipid droplets in both protocols is confirmed by Western Blot analysis. The droplet fractions from both preps

  11. Frangible electrochemical cell and sealing technique

    Science.gov (United States)

    Halpert, G.; Haynos, J.; Sherfey, J.

    1969-01-01

    Electrochemical cell assembly, which includes a positive electrode plate between two negative electrode plates, is both flexible and compact, and frangible under severe shock conditions. Leak-tight integrity of the housing is maintained by polymer-to-polymer fusion bonds through holes in the expanded metal electrode terminals.

  12. Cell-Detection Technique for Automated Patch Clamping

    Science.gov (United States)

    McDowell, Mark; Gray, Elizabeth

    2008-01-01

    A unique and customizable machinevision and image-data-processing technique has been developed for use in automated identification of cells that are optimal for patch clamping. [Patch clamping (in which patch electrodes are pressed against cell membranes) is an electrophysiological technique widely applied for the study of ion channels, and of membrane proteins that regulate the flow of ions across the membranes. Patch clamping is used in many biological research fields such as neurobiology, pharmacology, and molecular biology.] While there exist several hardware techniques for automated patch clamping of cells, very few of those techniques incorporate machine vision for locating cells that are ideal subjects for patch clamping. In contrast, the present technique is embodied in a machine-vision algorithm that, in practical application, enables the user to identify good and bad cells for patch clamping in an image captured by a charge-coupled-device (CCD) camera attached to a microscope, within a processing time of one second. Hence, the present technique can save time, thereby increasing efficiency and reducing cost. The present technique involves the utilization of cell-feature metrics to accurately make decisions on the degree to which individual cells are "good" or "bad" candidates for patch clamping. These metrics include position coordinates (x,y) in the image plane, major-axis length, minor-axis length, area, elongation, roundness, smoothness, angle of orientation, and degree of inclusion in the field of view. The present technique does not require any special hardware beyond commercially available, off-the-shelf patch-clamping hardware: A standard patchclamping microscope system with an attached CCD camera, a personal computer with an imagedata- processing board, and some experience in utilizing imagedata- processing software are all that are needed. A cell image is first captured by the microscope CCD camera and image-data-processing board, then the image

  13. Cy5 total protein normalization in Western blot analysis.

    Science.gov (United States)

    Hagner-McWhirter, Åsa; Laurin, Ylva; Larsson, Anita; Bjerneld, Erik J; Rönn, Ola

    2015-10-01

    Western blotting is a widely used method for analyzing specific target proteins in complex protein samples. Housekeeping proteins are often used for normalization to correct for uneven sample loads, but these require careful validation since expression levels may vary with cell type and treatment. We present a new, more reliable method for normalization using Cy5-prelabeled total protein as a loading control. We used a prelabeling protocol based on Cy5 N-hydroxysuccinimide ester labeling that produces a linear signal response. We obtained a low coefficient of variation (CV) of 7% between the ratio of extracellular signal-regulated kinase (ERK1/2) target to Cy5 total protein control signals over the whole loading range from 2.5 to 20.0μg of Chinese hamster ovary cell lysate protein. Corresponding experiments using actin or tubulin as controls for normalization resulted in CVs of 13 and 18%, respectively. Glyceraldehyde-3-phosphate dehydrogenase did not produce a proportional signal and was not suitable for normalization in these cells. A comparison of ERK1/2 signals from labeled and unlabeled samples showed that Cy5 prelabeling did not affect antibody binding. By using total protein normalization we analyzed PP2A and Smad2/3 levels with high confidence.

  14. Single-cell epigenomics: techniques and emerging applications.

    Science.gov (United States)

    Schwartzman, Omer; Tanay, Amos

    2015-12-01

    Epigenomics is the study of the physical modifications, associations and conformations of genomic DNA sequences, with the aim of linking these with epigenetic memory, cellular identity and tissue-specific functions. While current techniques in the field are characterizing the average epigenomic features across large cell ensembles, the increasing interest in the epigenetics within complex and heterogeneous tissues is driving the development of single-cell epigenomics. We review emerging single-cell methods for capturing DNA methylation, chromatin accessibility, histone modifications, chromosome conformation and replication dynamics. Together, these techniques are rapidly becoming a powerful tool in studies of cellular plasticity and diversity, as seen in stem cells and cancer.

  15. BLOTS AND ALL: A HISTORY OF THE RORSCHACH INK BLOT TEST IN BRITAIN.

    Science.gov (United States)

    Hubbard, Katherine; Hegarty, Peter

    2016-01-01

    Despite the easily recognizable nature of the Rorschach ink blot test very little is known about the history of the test in Britain. We attend to the oft-ignored history of the Rorschach test in Britain and compare it to its history in the US. Prior to the Second World War, Rorschach testing in Britain had attracted advocates and critiques. Afterward, the British Rorschach Forum, a network with a high proportion of women, developed around the Tavistock Institute in London and The Rorschach Newsletter. In 1968, the International Rorschach Congress was held in London but soon after the group became less exclusive, and fell into decline. A comparative account of the Rorschach in Britain demonstrates how different national institutions invested in the 'projective hypothesis' according to the influence of psychoanalysis, the adoption of a nationalized health system, and the social positioning of 'others' throughout the twentieth century. In comparing and contrasting the history of the Rorschach in Britain and the US, we decentralize and particularize the history of North American Psychology.

  16. A flow cytometry technique to study intracellular signals NF-κB and STAT3 in peripheral blood mononuclear cells

    Directory of Open Access Journals (Sweden)

    Chavarin Patricia

    2007-07-01

    Full Text Available Abstract Background Cytokines have essential roles on intercellular communications and are effective in using a variety of intracellular pathways. Among this multitude of signalling pathways, the NF-κB (nuclear factor kappaB and STAT (signal transducer and activator of transcription families are among the most frequently investigated because of their importance. Indeed, they have important role in innate and adaptive immunity. Current techniques to study NF-κB and STAT rely on specific ELISAs, Western Blots and – most recently described – flow cytometry; so far, investigation of such signalling pathways are most commonly performed on homogeneous cells after purification. Results The present investigation aimed at developing a flow cytometry technique to study transcription factors in various cellular types such as mixtures of B-cells, T-lymphocytes and monocytes/macrophages stimulated in steady state conditions (in other words, as peripheral blood mononuclear cells. To achieve this goal, a two step procedure was carried out; the first one consisted of stimulating PBMCs with IL1β, sCD40L and/or IL10 in such a manner that optimal stimulus was found for each cell subset (and subsequent signal transduction, therefore screened by specific ELISA; the second step consisted of assessing confirmation and fine delineation of technical conditions by specific Western-Blotting for either NF-κB or STAT products. We then went on to sensitize the detection technique for mixed cells using 4 color flow cytometry. Conclusion In response to IL1β, or IL10, the levels of phosphorylated NF-κB and STAT3 – respectively – increased significantly for all the studied cell types. In contrast, B-cells and monocytes/macrophages – but, interestingly, not T-lymphocytes (in the context of PBMCs – responded significantly to sCD40L by increasing phosphorylated NF-κB.

  17. [Application of cell co-culture techniques in medical studies].

    Science.gov (United States)

    Luo, Yun; Sun, Gui-Bo; Qin, Meng; Yao, Fan; Sun, Xiao-Bo

    2012-11-01

    As the cell co-culture techniques can better imitate an in vivo environment, it is helpful in observing the interactions among cells and between cells and the culture environment, exploring the effect mechanisms of drugs and their possible targets and filling the gaps between the mono-layer cell culture and the whole animal experiments. In recently years, they has attracted much more attention from the medical sector, and thus becoming one of research hotspots in drug research and development and bio-pharmaceutical fields. The cell co-culture techniques, including direct and indirect methods, are mainly used for studying pathological basis, new-type treatment methods and drug activity screening. Existing cell co-culture techniques are used for more pharmacological studies on single drug and less studies on interaction of combined drugs, such as collaborative compatibility and attenuation and synergistic effect among traditional Chinese medicines (TCMs). In line with the action characteristics of multi-component and multi-target, the cell co-culture techniques provide certain reference value for future studies on the effect and mechanism of combined TCMs on organisms as well as new methods for studies on TCMs and their compounds. This essay summarizes cell co-culture methods and their application and look into the future of their application in studies on TCMs and compounds.

  18. Characterization of Nora Virus Structural Proteins via Western Blot Analysis

    Directory of Open Access Journals (Sweden)

    Brad L. Ericson

    2016-01-01

    Full Text Available Nora virus is a single stranded RNA picorna-like virus with four open reading frames (ORFs. The coding potentials of the ORFs are not fully characterized, but ORF3 and ORF4 are believed to encode the capsid proteins (VP3, VP4a, VP4b, and VP4c comprising the virion. To determine the polypeptide composition of Nora virus virions, polypeptides from purified virus were compared to polypeptides detected in Nora virus infected Drosophila melanogaster. Nora virus was purified from infected flies and used to challenge mice for the production of antisera. ORF3, ORF4a, ORF4b, and ORF4c were individually cloned and expressed in E. coli; resultant recombinant proteins purified and were used to make monospecific antisera. Antisera were evaluated via Western blot against whole virus particles and Nora virus infected fly lysates. Viral purification yielded two particle types with densities of ~1.31 g/mL (empty particles and ~1.33 g/mL (complete virions. Comparison of purified virus polypeptide composition to Nora virus infected D. melanogaster lysate showed the number of proteins in infected cell lysates is less than purified virus. Our results suggest the virion is composed of 6 polypeptides, VP3, VP4a, two forms of VP4b, and two forms of VP4c. This polypeptide composition is similar to other small RNA insect viruses.

  19. The Use of Biotin to Demonstrate Immunohistochemistry, Western Blotting, and Dot Blots in University Practical Classes

    Science.gov (United States)

    Millar, Thomas James; Knighton, Ronald; Chuck, Jo-Anne

    2012-01-01

    Immunological detection of proteins is an essential method to demonstrate to undergraduate biology students, however, is often difficult in resource and time poor student laboratory sessions. This method describes a failsafe method to rapidly and economically demonstrate this technique using biotinylated proteins or biotin itself as targets for…

  20. Mixed lubrication after rewetting of blotted pleural mesothelium.

    Science.gov (United States)

    Bodega, Francesca; Sironi, Chiara; Porta, Cristina; Pecchiari, Matteo; Zocchi, Luciano; Agostoni, Emilio

    2013-01-15

    Coefficient of kinetic friction (μ) of pleural mesothelium blotted with filter paper, and rewetted with Ringer solution markedly increases; this increase is removed if a sufficient amount of sialomucin or hyaluronan is added to Ringer (Bodega et al., 2012. Respiratory Physiology and Neurobiology 180, 34-39). In this research we found that μ of pleural mesothelium blotted, rewetted, and sliding at physiological velocities and loads, decreased with increase of velocity, mainly at low velocities. Despite this decrease, μ at highest velocity was still double that before blotting. With small concentration of sialomucin or hyaluronan μ was markedly smaller at each velocity, decreased less with increase of velocity, and at highest velocity approached preblotting value. These findings indicate a regime of mixed lubrication in post-blotting Ringer, at variance with boundary lubrication occurring before blotting or postblotting with sufficient macromolecule addition. Greater roughness of mesothelial surface, caused by blotting, likely induces zones of elastohydrodynamic lubrication, which increase with velocity, while contact area decreases.

  1. GTP-blot analysis of small GTP-binding proteins. The C-terminus is involved in renaturation of blotted proteins.

    Science.gov (United States)

    Klinz, F J

    1994-10-01

    Recombinant c-Ha-ras, ralA and rap2, but not rap1A or rap1B proteins retained their ability to bind [alpha-32P]GTP after SDS/PAGE and transfer to nitrocellulose. Recombinant c-Has-ras missing the C-terminal 23 amino acid residues failed to bind [alpha-32P]GTP after the blot, and the ability of recombinant ralA missing the C-terminal 28 amino acid residues to bind [alpha-32P]GTP was decreased many-fold. The presence of nonionic detergents of the polyoxyethylene type such as Tween 20, Triton X-100, Nonidet P40 or Lubrol PX in the incubation buffer was necessary to induce renaturation of blotted recombinant c-Ha-ras protein, whereas other types of detergents were ineffective. We propose that detergents of the polyoxyethylene type induce the refolding of some types of blotted small GTP-binding proteins and that the C-terminus is involved in the refolding process. Membranes from NIH3T3 fibroblasts overexpressing c-Ha-ras protein showed much weaker binding of [alpha-32P]GTP as expected from the level of ras immunoreactivity. Treatment of fibroblasts with lovastatin, an inhibitor of hydroxymethylglutaryl-coenzyme A reductase, caused the accumulation of the unfarnesylated form of c-Ha-ras in the cytosol. Examination of [alpha-32P]GTP-binding and immunoreactivity for cytosolic and membrane-bound c-Ha-ras revealed that binding of [alpha-32P]GTP to unprocessed c-Ha-ras was increased about threefold compared to the same amount of processed c-Ha-ras. Our results demonstrate that detection and quantification of small GTP-binding proteins in eukaryotic cells by GTP-blot analysis is hampered by the fact that these proteins differ strongly in their ability to renature after blotting to nitrocellulose.

  2. Sparse grid techniques for particle-in-cell schemes

    CERN Document Server

    Ricketson, Lee F

    2016-01-01

    We propose the use of sparse grids to accelerate particle-in-cell (PIC) schemes. By using the so-called `combination technique' from the sparse grids literature, we are able to dramatically increase the size of the spatial cells in multi-dimensional PIC schemes while paying only a slight penalty in grid-based error. The resulting increase in cell size allows us to reduce the statistical noise in the simulation without increasing total particle number. We present initial proof-of-principle results from test cases in two and three dimensions that demonstrate the new scheme's efficiency, both in terms of computation time and memory usage.

  3. Controlled shear filtration: A novel technique for animal cell separation.

    Science.gov (United States)

    Vogel, J H; Kroner, K H

    1999-06-20

    A novel rotary microfiltration technique specifically suited for the separation of animal cells has been developed. The concept allows the independent adjustment of wall shear stress, transmembrane pressure, and residence time, allowing straightforward optimization of the microfiltration process. By using a smooth, conically shaped rotor, it is possible to establish a controlled shear field in which animal cells experience a significant hydrodynamic lift away from the membrane surface. It is shown in preliminary experiments that shear-induced cell-rupture speeds up membrane clogging and that cell debris poses the most significant problem in harvesting of BHK cell cultures by dynamic microfiltration. However, a threshold value of shear stability exists which depends on the frequency of passing the shear field, the residence time in the shear field, as well as on cell status. By operating close to this threshold value, cell viability can be maintained while concentration polarization is efficiently minimized. By applying this concept, it is possible to attain flux rates several times higher compared to conventional crossflow filtration. Controlled shear filtration (CSF) can be used for batch harvesting as well as for cell retention in high cell density systems. In batch harvesting of hIL-2 from rBHK cell culture, a constant flux rate of 290 L h-1 m-2 has been adjusted without indication of membrane clogging or fouling.

  4. Use of a Combined Duplex PCR/Dot Blot Assay for more sensitive genetic characterization

    Directory of Open Access Journals (Sweden)

    Erin Curry

    2008-01-01

    Full Text Available A reliable and sensitive method of genetic analysis is necessary to detect multiple specific nucleic acid sequences from samples containing limited template. The most widely utilized method of specific gene detection, polymerase chain reaction (PCR, imparts inconsistent results when assessing samples with restricted template, especially in a multiplex reaction when copies of target genes are unequal. This study aimed to compare two methods of PCR product analysis, fluorescent detection following agarose gel electrophoresis or dot blot hybridization with chemiluminescent evaluation, in the detection of a single copy gene (SRY and a multicopy gene (β-actin. Bovine embryo sex determination was employed to exploit the limited DNA template available and the target genes of unequal copies. Primers were used either independently or together in a duplex reaction with purified bovine genomic DNA or DNA isolated from embryos. When used independently, SRY and β-actin products were detected on a gel at the equivalent of 4-cell or 1-cell of DNA, respectively; however, the duplex reaction produced visible SRY bands at the 256 cell DNA equivalent and β-actin products at the 64 cell DNA equivalent. Upon blotting and hybridization of the duplex PCR reaction, product was visible at the 1–4 cell DNA equivalent. Duplex PCR was also conducted on 186 bovine embryos and product was subjected to gel electrophoresis or dot-blot hybridization in duplicate. Using PCR alone, sex determination was not possible for 22.6% of the samples. Using PCR combined with dot blot hybridization, 100.0% of the samples exhibited either both the male specific and β-actin products or the β-actin signal alone, indicating that the reaction worked in all samples. This study demonstrated that PCR amplification followed by dot blot hybridization provided more conclusive results in the evaluation of samples with low DNA concentrations and target genes of unequal copies.

  5. Apheresis techniques for collection of peripheral blood progenitor cells.

    Science.gov (United States)

    Moog, Rainer

    2004-12-01

    The combination of effective mobilisation protocols and efficient use of apheresis machines has caused peripheral blood progenitor cells (PBPC) transplantation to grow rapidly. The development of apheresis technology has improved over the years. Today PBSC procedures have changed towards systems to minimise operator interaction and to reduce the collection of undesired cells such as polymorphonuclear cells and platelets using functionally closed, sterile environments for PBSC collection in keeping with Good Manufacturing Practice guidelines. Blood cell separators with continuous flow technique allow the processing of more blood than intermittent flow devices resulting in higher PBSC yields. Large volume leukapheresis with the processing of 3-4-fold donor's/patient's blood volume can increase the number of collected progenitor cells. Therefore, intermittent flow cell separators are indicated if only single vein access is available. Anticoagulant induced hypocalcaemia is an often observed side effect in long lasting PBPC harvesting and monitoring of electrolytes should be performed especially at the end of the apheresis procedure to supplement low levels of potassium, calcium or magnesium. Refinement and improvement of collection techniques continue to add to the armamentarium of current approaches for cancer and non-malignant conditions and will enable future strategies.

  6. Routine Western blot to check autophagic flux : Cautions and recommendations

    NARCIS (Netherlands)

    Gomez-Sanchez, Ruben; Pizarro-Estrella, Elisa; Yakhine-Diop, Sokhna M. S.; Rodriguez-Arribas, Mario; Bravo-San Pedro, Jose M.; Fuentes, Jose M.; Gonzalez-Polo, Rosa A.

    2015-01-01

    At present, the analysis of autophagic flux by Western blotting (WB), which measures two of the most important markers of autophagy, i.e., microtubule-associated protein 1 light chain 3 (LC3) and p62, is widely accepted in the scientific community. In this study, we addressed the possible disadvanta

  7. Simultaneous preparation of RNA and nuclei for Northern blot and flow cytometric analysis

    Energy Technology Data Exchange (ETDEWEB)

    Tesfaigzi, J.; Jaramillo, R. [Inhalation Toxicology Research Inst., Albuquerque, NM (United States)

    1996-11-01

    Several methods have been developed to quantify RNA synthesis during the progression of the cell cycle. The rate of RNA synthesis can be detected during different stages of the cell cycle by staining cells with agents that intercalate with nucleic acids. For example, following staining of mammalian cells with acridin orange, the green and red fluorescence that correlates with DNA and RNA content, respectively, can be analyzed by flow cytometry. Increase in RNA content during the progression of cells through the cell cycle can be measured after staining with acridin orange. RNA synthesis resulting from the stimulation of quiescent cells with various growth factors has also been demonstrated by labeling cells with bromo-uridine and using the anti-bromo-deoxyuridine antibody. These methods allow measurement of the overall RNA content in cells; however, they do not allow the measurement of the levels of specific mRNAs throughout the cell cycle. Current methods to quantify specific mRNAs generally require the preparation of a large number of cells (5--10 {times} 10{sup 6} cells) to carry out flow cytometric analyses and to isolate RNA for Northern blot analysis or solution hybridization. In this report, the authors describe a method of simultaneously preparing RNA and nuclei for Northern blot and flow cytometric analyses, respectively. The minimum number of nuclei required to obtain flow cytometric data and the effect of conserving nuclei in methanol for several days are also presented.

  8. HOUSE DUST MITE ALLERGEN (Derp1 AND Blot5) LEVELS IN ASTHMATICS' HOME IN HONGKONG

    Institute of Scientific and Technical Information of China (English)

    Bao-qing Sun; Adrian Wu; Albert Chan; Stanley Chik; Dorothy Wong; Nan-shan Zhong

    2004-01-01

    Objective To measure Derpl and Blot5 allergen levels in asthmatics' homes in Hongkong.Methods Seventy houses were enrolled for a mite indoor environment study. Dust samples were obtained from two sites of each patients' house: bed and floor. Derpl and Blot5 levels were quantified by a two-site monoclonal antibody-based ELISA technique.Results The levels of Derpl allergens found in bed (geometric mean (GM) 3.43 μg/g of dust; 95%CI, 1.89-4.96 μg/g)and on the floor (GM 1.12 μg/g of dust; 95%CI, 0.71-1.53 μg/g) indicated significant differences (P=0.005). However, the levels of Blot5 allergens found in bed (GM 19.00 μg/g of dust; 95%CI, 0.89-38.90 μg/g) and on the floor (GM 6.14 μg/g of dust; 95%CI, 0.40-11.90 μg/g) showed no statistically significant difference. In addition, in regards to the exposure index for Derpl and Blot5 allergens found in bed and on the floor, 17.6% in bed and 8.6% on the floor had levels of Blot5 ≥ 10 μg/g of dust, higher than those obtained for Derp1 (7.2% and 0% in bed and on the floor respectively, P< 0.05); higher percentages in bed and on the floor (25.0% and 35.7%) were observed for levels of Blot5 =0 μg/g of dust as compared with Derpl in bed and on the floor (4.3% and 14.5% respectively, P< 0.05).Conclusions Derpl and Blot5 are the major allergens found in this regional study, Blot5 is a more potent allergen in Hongkong, probably reflecting the high level of exposure to Blomia tropicalis (Bt). Bt and Dermatophagoides pteronyssinus (Dp) allergens should be included for precise diagnosis and effective immuno-therapeutic treatment of mite allergy in Hongkong.

  9. Combined use of Western blot/ELISA to improve the serological diagnosis of human tuberculosis

    Directory of Open Access Journals (Sweden)

    S. T. Beck

    2005-02-01

    Full Text Available Two recombinant antigens and a crude bacterial antigen of a wild M. tuberculosis strain were used to detect specific IgG antibodies in sera from 52 patients with pulmonary tuberculosis, confirmed by an acid-fast smear and serum culture of these patients and that of 25 contacts. The patients were not infected with HIV. We evaluated the sensitivity and specificity of ELISA, based on the recombinant TbF6® and TbF6/DPEP antigen and a search for reactivity patterns in the Western blot technique, using whole mycobacterium antigen. Serum samples from 22 healthy individuals and from 30 patients with lung diseases other than tuberculosis were used as controls. The best ELISA results were obtained with the TbF6/DPEP antigen combination, which gave 85% sensitivity and 91% specificity. ELISA sensitivity improved from 85% to 92% when the Western blot results were used. Western blot specificity was 100% when antibody reactivity with different antigenic bands was analyzed and associated. The association of TbF6/DPEP antigens used in ELISA with specific patterns of reactivity determined by Western blot can help make an identification when classic methods for the diagnosis of pulmonary tuberculosis are not sufficient.

  10. Miniaturized fluorescent RNA dot blot method for rapid quantitation of gene expression

    Directory of Open Access Journals (Sweden)

    Yadetie Fekadu

    2004-06-01

    Full Text Available Abstract Background RNA dot blot hybridization is a commonly used technique for gene expression assays. However, membrane based RNA dot/slot blot hybridization is time consuming, requires large amounts of RNA, and is less suited for parallel assays of more than one gene at a time. Here, we describe a glass-slide based miniaturized RNA dot blot (RNA array procedure for rapid and parallel gene expression analysis using fluorescently labeled probes. Results RNA arrays were prepared by simple manual spotting of RNA onto amino-silane coated microarray glass slides, and used for two-color fluorescent hybridization with specific probes labeled with Cy3 and 18S ribosomal RNA house-keeping gene probe labeled with Cy5 fluorescent dyes. After hybridization, arrays were scanned on a fluorescent microarray scanner and images analyzed using microarray image analysis software. We demonstrate that this method gives comparable results to Northern blot analysis, and enables high throughput quantification of transcripts from nanogram quantities of total RNA in hundreds of samples. Conclusion RNA array on glass slide and detection by fluorescently labeled probes can be used for rapid and parallel gene expression analysis. The method is particularly well suited for gene expression assays that involve quantitation of many transcripts in large numbers of samples.

  11. An IMRT/VMAT Technique for Nonsmall Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Nan Zhao

    2015-01-01

    Full Text Available The study is to investigate a Hybrid IMRT/VMAT technique which combines intensity modulated radiation therapy (IMRT and volumetric modulated arc therapy (VMAT for the treatment of nonsmall cell lung cancer (NSCLC. Two partial arcs VMAT, 5-field IMRT, and hybrid plans were created for 15 patients with NSCLC. The hybrid plans were combination of 2 partial arcs VMAT and 5-field IMRT. The dose distribution of planning target volume (PTV and organs at risk (OARs for hybrid technique was compared with IMRT and VMAT. The monitor units (MUs and treatment delivery time were also evaluated. Hybrid technique significantly improved the target conformity and homogeneity compared with IMRT and VMAT. The mean delivery time of IMRT, VMAT, and hybrid plans was 280 s, 114 s, and 327 s, respectively. The mean MUs needed for IMRT, VMAT, and hybrid plans were 933, 512, and 737, respectively. Hybrid technique reduced V5, V10, V30, and MLD of normal lung compared with VMAT and spared the OARs better with fewer MUs with the cost of a little higher V5, V10, and mean lung dose (MLD of normal lung compared with IMRT. Hybrid IMRT/VMAT can be a viable radiotherapy technique with better plan quality.

  12. An IMRT/VMAT Technique for Nonsmall Cell Lung Cancer.

    Science.gov (United States)

    Zhao, Nan; Yang, Ruijie; Wang, Junjie; Zhang, Xile; Li, Jinna

    2015-01-01

    The study is to investigate a Hybrid IMRT/VMAT technique which combines intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) for the treatment of nonsmall cell lung cancer (NSCLC). Two partial arcs VMAT, 5-field IMRT, and hybrid plans were created for 15 patients with NSCLC. The hybrid plans were combination of 2 partial arcs VMAT and 5-field IMRT. The dose distribution of planning target volume (PTV) and organs at risk (OARs) for hybrid technique was compared with IMRT and VMAT. The monitor units (MUs) and treatment delivery time were also evaluated. Hybrid technique significantly improved the target conformity and homogeneity compared with IMRT and VMAT. The mean delivery time of IMRT, VMAT, and hybrid plans was 280 s, 114 s, and 327 s, respectively. The mean MUs needed for IMRT, VMAT, and hybrid plans were 933, 512, and 737, respectively. Hybrid technique reduced V5, V10, V30, and MLD of normal lung compared with VMAT and spared the OARs better with fewer MUs with the cost of a little higher V5, V10, and mean lung dose (MLD) of normal lung compared with IMRT. Hybrid IMRT/VMAT can be a viable radiotherapy technique with better plan quality.

  13. A spin-drying technique for lyopreservation of mammalian cells.

    Science.gov (United States)

    Chakraborty, Nilay; Chang, Anthony; Elmoazzen, Heidi; Menze, Michael A; Hand, Steven C; Toner, Mehmet

    2011-05-01

    Stabilization of cellular material in the presence of glass-forming sugars at ambient temperatures is a viable approach that has many potential advantages over current cryogenic strategies. Experimental evidence indicates the possibility to preserve biomolecules in glassy matrices of low-molecular mobility using "glass-forming" sugars like trehalose at ambient temperatures. However, when cells are desiccated in trehalose solution using passive drying techniques, a glassy skin is formed at the liquid/vapor interface of the sample. This glassy skin prevents desiccation of the sample beyond a certain level of dryness and induces non-uniformities in the final water content. Cells trapped underneath this glassy skin may degrade due to a relatively high molecular mobility in the sample. This undesirable result underscores the need for development of a uniform, fast drying technique. In the present study, we report a new technique based on the principles of "spin drying" that can effectively address these problems. Forced convective evaporation of water along with the loss of solution due to centrifugal force leads to rapid vitrification of a thin layer of trehalose containing medium that remains on top of cells attached to the spinning glass substrate. The glassy layer produced has a consistent thickness and a small "surface-area-to-volume" ratio that minimizes any non-homogeneity. Thus, the chance of entrapping cells in a high-mobility environment decreases substantially. We compared numerical predictions to experimental observations of the drying time of 0.2-0.6 M trehalose solutions at a variety of spinning speeds ranging from 1000 to 4000 rpm. The model developed here predicts the formation of sugar films with thicknesses of 200-1000 nm, which was in good agreement with experimental results. Preliminary data suggest that after spin drying cells to about 0.159 ± 0.09 gH₂O/gdw (n = 11, ±SE), more than 95% of cells were able to preserve their membrane integrity

  14. High Rate Laser Pitting Technique for Solar Cell Texturing

    Energy Technology Data Exchange (ETDEWEB)

    Hans J. Herfurth; Henrikki Pantsar

    2013-01-10

    High rate laser pitting technique for solar cell texturing Efficiency of crystalline silicon solar cells can be improved by creating a texture on the surface to increase optical absorption. Different techniques have been developed for texturing, with the current state-of-the-art (SOA) being wet chemical etching. The process has poor optical performance, produces surfaces that are difficult to passivate or contact and is relatively expensive due to the use of hazardous chemicals. This project shall develop an alternative process for texturing mc-Si using laser micromachining. It will have the following features compared to the current SOA texturing process: -Superior optical surfaces for reduced front-surface reflection and enhanced optical absorption in thin mc-Si substrates -Improved surface passivation -More easily integrated into advanced back-contact cell concepts -Reduced use of hazardous chemicals and waste treatment -Similar or lower cost The process is based on laser pitting. The objective is to develop and demonstrate a high rate laser pitting process which will exceed the rate of former laser texturing processes by a factor of ten. The laser and scanning technologies will be demonstrated on a laboratory scale, but will use inherently technologies that can easily be scaled to production rates. The drastic increase in process velocity is required for the process to be implemented as an in-line process in PV manufacturing. The project includes laser process development, development of advanced optical systems for beam manipulation and cell reflectivity and efficiency testing. An improvement of over 0.5% absolute in efficiency is anticipated after laser-based texturing. The surface textures will be characterized optically, and solar cells will be fabricated with the new laser texturing to ensure that the new process is compatible with high-efficiency cell processing. The result will be demonstration of a prototype process that is suitable for scale-up to a

  15. Effects of Reusing Gel Electrophoresis and Electrotransfer Buffers on Western Blotting

    Science.gov (United States)

    Omotola, Oluwabukola B.; Heda, Rajiv P.; Avery, Jamie

    2016-01-01

    SDS-PAGE and Western blotting are 2 of the most commonly used biochemical methods for protein analysis. Proteins are electrophoretically separated based on their MWs by SDS-PAGE and then electrotransferred to a solid membrane surface for subsequent protein-specific analysis by immunoblotting, a procedure commonly known as Western blotting. Both of these procedures use a salt-based buffer, with the latter procedure consisting of methanol as an additive known for its toxicity. Previous reports present a contradictory view in favor or against reusing electrotransfer buffer, also known as Towbin’s transfer buffer (TTB), with an aim to reduce the toxic waste. In this report, we present a detailed analysis of not only reusing TTB but also gel electrophoresis buffer (EB) on proteins of low to high MW range. Our results suggest that EB can be reused for at least 5 times without compromising the electrophoretic separation of mixture of proteins in an MW standard, BSA, and crude cell lysates. Additionally, reuse of EB did not affect the quality of subsequent Western blots. Successive reuse of TTB, on the other hand, diminished the signal of proteins of different MWs in a protein standard and a high MW membrane protein cystic fibrosis transmembrane-conductance regulator (CFTR) in Western blotting. PMID:27582639

  16. Advances in PEM fuel cells with CFD techniques

    Energy Technology Data Exchange (ETDEWEB)

    Robalinho, Eric; Cunha, Edgar Ferrari da; Zararya, Ahmed; Linardi, Marcelo [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], Email: eric@ipen.br; Cekinski, Efrain [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil)

    2010-07-01

    This paper presents some applications of computational fluid dynamics techniques in the optimization of Proton Exchange Membrane Fuel Cell (PEMFC) designs. The results concern: modeling of gas distribution channels, the study for both porous anode and cathode and the three-dimensional modeling of a partial geometry layer containing catalytic Gas Diffusion Layers (GDL) and membrane. Numerical results of the simulations of graphite plates flow channels, using ethanol as fuel, are also presented. Some experimental results are compared to the corresponding numerical ones for several cases, demonstrating the importance and usefulness of this computational tool. (author)

  17. Biofilm detection by wound blotting can predict slough development in pressure ulcers: A prospective observational study.

    Science.gov (United States)

    Nakagami, Gojiro; Schultz, Gregory; Gibson, Daniel J; Phillips, Priscilla; Kitamura, Aya; Minematsu, Takeo; Miyagaki, Tomomitsu; Hayashi, Akitatsu; Sasaki, Sanae; Sugama, Junko; Sanada, Hiromi

    2016-12-26

    Bacteria have been found to form multicellular aggregates which have collectively been termed "biofilms." It is hypothesized that biofilm formation is a means to protect bacterial cells including protection form the immune response of humans. This protective mechanism is believed to explain persistent chronic wound infections. At times, the biofilms are abundant enough to see, and remove by simple wiping. However, recent evidence has shown that the removal of these visible portions are not sufficient, and that biofilms can continue to form even with daily wiping. In this work, we tested an approach to detect the biofilms which are present after clinically wiping or sharp wound debridement. Our method is based on a variation of impression cytology in which a nitrocellulose membrane was used to collect surface biofilm components, which were then differentially stained. In this prospective study, members of an interdisciplinary pressure ulcer team at a university hospital tested our method's ability to predict the generation of wound slough in the week that followed each blotting. A total of 70 blots collected from 23 pressure ulcers produced 27 wounds negative for staining and 43 positive. In the negative blots 55.6% were found to have decreased wound slough, while 81.4% with positive staining had either increase or unchanged wound slough generation. These results lead to an odds ratio of positive blotting cases of 9.37 (95% confidence intervals: 2.47-35.5, p = 0.001) for slough formation; suggesting that the changes in wound slough formation can be predicted clinically using a non-invasive wound blotting method.

  18. Cells and Stripes: A novel quantitative photo-manipulation technique.

    Science.gov (United States)

    Mistrik, Martin; Vesela, Eva; Furst, Tomas; Hanzlikova, Hana; Frydrych, Ivo; Gursky, Jan; Majera, Dusana; Bartek, Jiri

    2016-01-18

    Laser micro-irradiation is a technology widely used in the DNA damage response, checkpoint signaling, chromatin remodeling and related research fields, to assess chromatin modifications and recruitment of diverse DNA damage sensors, mediators and repair proteins to sites of DNA lesions. While this approach has aided numerous discoveries related to cell biology, maintenance of genome integrity, aging and cancer, it has so far been limited by a tedious manual definition of laser-irradiated subcellular regions, with the ensuing restriction to only a small number of cells treated and analyzed in a single experiment. Here, we present an improved and versatile alternative to the micro-irradiation approach: Quantitative analysis of photo-manipulated samples using innovative settings of standard laser-scanning microscopes. Up to 200 cells are simultaneously exposed to a laser beam in a defined pattern of collinear rays. The induced striation pattern is then automatically evaluated by a simple algorithm, which provides a quantitative assessment of various laser-induced phenotypes in live or fixed cells. Overall, this new approach represents a more robust alternative to existing techniques, and provides a versatile tool for a wide range of applications in biomedicine.

  19. HIV‑2 antibody detection after indeterminate or negative HIV‑1 Western blot in Cuba, 2005-2008.

    Science.gov (United States)

    Díaz, Dervel F; Ortiz, Eva; Martín, Dayamí; Nibot, Carmen; Rizo, Adis; Silva, Eladio

    2012-01-01

    that HIV-2 Western blot be included in the diagnostic algorithm for HIV-1/2 to followup negative or indeterminate HIV-1 Western blot results. KEYWORDS Diagnosis, laboratory techniques and procedures, antibodies, HIV-2, Western blot, enzyme-linked immunosorbent assay, algorithm, Cuba.

  20. Standardization of Licorice and TCM Formulations Using Eastern Blot Fingerprinting Analysis

    Directory of Open Access Journals (Sweden)

    Yukihiro Shoyama

    2013-01-01

    Full Text Available To prepare the antiglycyrrhizin (GC monoclonal antibody (MAb, GC was treated with NaIO4 resulting in aldehyde which can be combined with carrier protein. An antigen conjugate was performed by a matrix-assisted laser desorption/ionization TOF mass spectrometry to determine the hapten numbers in the conjugate. Anti-GC MAb was prepared from a hybridoma which was fixed from the spleen cells producing anti-GC MAb and the myeloma cells after immunization. The TCM and licorice extract were developed by TLC and blotted to a polyvinylidene difluoride (PVDF membrane. The membrane was treated by NaIO4 and protein, enzyme labeled secondary MAb, and finally substrate was added. Clear spot appeared on PVDF membrane identifying GC against a background containing large amount of impurities. In eastern blotting, the GC molecule was divided into two functions. The aglycone part is recognized as an epitope and the sugar moiety can be combined to membrane. The specific reactivity of sugar moiety in the GC molecule against anti-GC MAb might be modified by the NaIO4 treatment on the membrane because glycyrrhetic acid 3-O-glucuronide can be stained although the cross-reactivity is only 4.3%. Eastern blotting for GC can not only apply for the standardization of licorice and TCM, but also it can open for the other bioactive products.

  1. Determination of Diagnostic Antigens in Cattle Amphistomiasis Using Western Blotting

    Directory of Open Access Journals (Sweden)

    A Halajian

    2009-05-01

    Full Text Available "nBackground: Mixed infection with amphistomes seems common in native cattle of Iran. The aim of this study was to determine diagnostic antigens in cattle mixed amphistomiasis."nMethods: Specific antigens of Cotylophoron cotylophorum, Gastrothylax crumenifer and Paramphisto­mum cervi (mixed infection, the most common species, were collected from cattle was deter­mined. Adult trematodes were collected from the rumen of naturally infected cattle at meat inspec­tion. After their homogenization and centrifugation, somatic antigens were prepared and ana­lyzed by SDS-PAGE. Specific antigens were determinated by western blot with homologous and heterolo­gous sera. SDS-PAGE of whole worms extract was performed at different concentrations and subse­quent gels staining. Immunoblotting analysis using sera from cattle naturally infected with am­phistomes, Dicrocoelium dendriticum, Fasciola spp. and hydatid cyst was performed."nResults: Electrophorese analysis of somatic antigens revealed the presence of 10 and 21 protein bands at 4 µgr/ml and 8 µgr/ml with molecular weights ranging from 25-120 and 25-150 kDa, respectively. The best result was taken at 8 mg/ml concentration. Although western blot of these proteins demon­strate 5 major antigenic polypeptides ranging from 50 to 100 kDa which were recognized by serum of cat­tle naturally infected with mixed amphistomes.

  2. Cell-level battery charge/discharge protection system. [electronic control techniques

    Science.gov (United States)

    Donovan, R. L.; Imamura, M. S.

    1977-01-01

    The paper describes three design approaches to individual cell monitoring and control for sealed secondary battery cells. One technique involves a modular strap-on single cell protector which contains all the electronics required for monitoring cell voltage, responding to external commands, and forming a bypass circuit for the cell. A second technique, the multiplexed cell protector, uses common circuitry to monitor and control each cell in a battery pack. The third technique, the computerized cell protector, by replacing the hard-wired logic of the multiplexed cell protector with a microprocessor, achieves greatest control flexibility and inherent computational capability with a minimum parts count implementation.

  3. Simplex-in-Cell Technique for Collisionless Plasma Simulations

    CERN Document Server

    Kates-Harbeck, Julian; Zrake, Jonathan; Abel, Tom

    2015-01-01

    We extend the simplex-in-cell (SIC) technique recently introduced in the context of collisionless dark matter fluids (Abel et al. 2012; Hahn et al. 2012) to the case of collisionless plasmas. The six-dimensional phase space distribution function $f(\\mathbf x,\\mathbf v)$ is represented by an ensemble of three-dimensional manifolds, which we refer to as sheets. The electric potential field is obtained by solving the Poisson equation on a uniform mesh, where the charge density is evaluated by a spatial projection of the phase space sheets. The SIC representation of phase space density facilitates robust, high accuracy numerical evolution of the Vlasov-Poisson system using significantly fewer tracer particles than comparable particle-in-cell (PIC) approaches by reducing the numerical shot-noise associated with the latter. We introduce the SIC formulation and describe its implementation in a new code, which we validate using standard test problems including plasma oscillations, Landau damping, and two stream insta...

  4. Simplex-in-cell technique for collisionless plasma simulations

    Science.gov (United States)

    Kates-Harbeck, Julian; Totorica, Samuel; Zrake, Jonathan; Abel, Tom

    2016-01-01

    We extend the simplex-in-cell (SIC) technique recently introduced in the context of collisionless dark matter fluids [1,2] to the case of collisionless plasmas. The six-dimensional phase space distribution function f (x , v) is represented by an ensemble of three-dimensional manifolds, which we refer to as sheets. The electric potential field is obtained by solving the Poisson equation on a uniform mesh, where the charge density is evaluated by a spatial projection of the phase space sheets. The SIC representation of phase space density facilitates robust, high accuracy numerical evolution of the Vlasov-Poisson system using significantly fewer tracer particles than comparable particle-in-cell (PIC) approaches by reducing the numerical shot-noise associated with the latter. We introduce the SIC formulation and describe its implementation in a new code, which we validate using standard test problems including plasma oscillations, Landau damping, and two stream instabilities in one dimension. Merits of the new scheme are shown to include higher accuracy and faster convergence rates in the number of particles. We finally motivate and outline the efficient application of SIC to higher dimensional problems.

  5. Recent Advancements and Techniques in Manufacture of Solar Cells: Organic Solar Cells

    Directory of Open Access Journals (Sweden)

    B. Naga Venkata Sai Ganesh,

    2013-03-01

    Full Text Available The major problem faced by the society is power crisis. All the non-renewable resources like fossil fuelsnecessary for producing power are being used excessively, which might result a day in future where, the world might godark due to lack of power producing resources. Usage of renewable resources like solar energy can be a solution to thisproblem. Solar cells invented to overcome this problem show rigidity in their structure which is a drawback. Inorganicsolar cells are rigid and can be mounted only on rooftops. Hence only upper surface of buildings are utilized. In this paperwe bring out a new era or solar cells- organic solar cells, which are flexible. These organic solar cells offer the bestsolution for the above problem for a tradeoff of efficiency. This paper briefs the manufacturing technique of solar cellsfrom plastic i.e. ,organic polymers, their architecture, the working process of solar energy production from the organicsolar cells with their ease of usage

  6. Techniques of Human Embryonic Stem Cell and Induced Pluripotent Stem Cell Derivation.

    Science.gov (United States)

    Lewandowski, Jarosław; Kurpisz, Maciej

    2016-10-01

    Developing procedures for the derivation of human pluripotent stem cells (PSCs) gave rise to novel pathways into regenerative medicine research. For many years, stem cells have attracted attention as a potentially unlimited cell source for cellular therapy in neurodegenerative disorders, cardiovascular diseases, and spinal cord injuries, for example. In these studies, adult stem cells were insufficient; therefore, many attempts were made to obtain PSCs by other means. This review discusses key issues concerning the techniques of pluripotent cell acquisition. Technical and ethical issues hindered the medical use of somatic cell nuclear transfer and embryonic stem cells. Therefore, induced PSCs (iPSCs) emerged as a powerful technique with great potential for clinical applications, patient-specific disease modelling and pharmaceutical studies. The replacement of viral vectors or the administration of analogous proteins or chemical compounds during cell reprogramming are modifications designed to reduce tumorigenesis risk and to augment the procedure efficiency. Intensified analysis of new PSC lines revealed other barriers to overcome, such as epigenetic memory, disparity between human and mouse pluripotency, and variable response to differentiation of some iPSC lines. Thus, multidimensional verification must be conducted to fulfil strict clinical-grade requirements. Nevertheless, the first clinical trials in patients with spinal cord injury and macular dystrophy were recently carried out with differentiated iPSCs, encouraging alternative strategies for potential autologous cellular therapies.

  7. Polymerase chain reaction and Southern blot-based analysis of the C9orf72 hexanucleotide repeat in different motor neuron diseases.

    Science.gov (United States)

    Hübers, Annemarie; Marroquin, Nicolai; Schmoll, Birgit; Vielhaber, Stefan; Just, Marlies; Mayer, Benjamin; Högel, Josef; Dorst, Johannes; Mertens, Thomas; Just, Walter; Aulitzky, Anna; Wais, Verena; Ludolph, Albert C; Kubisch, Christian; Weishaupt, Jochen H; Volk, Alexander E

    2014-05-01

    The GGGGCC-hexanucleotide repeat expansion in C9orf72 is the most common genetic cause of familial amyotrophic lateral sclerosis and frontotemporal dementia. This study determined the frequency of C9orf72 repeat expansions in different motor neuron diseases (amyotrophic lateral sclerosis (ALS), motor neuron diseases affecting primarily the first or the second motor neuron and hereditary spastic paraplegia). Whereas most studies on C9orf72 repeat expansions published so far rely on a polymerase chain reaction-based screening, we applied both polymerase chain reaction-based techniques and Southern blotting. Furthermore, we determined the sensitivity and specificity of Southern blotting of the C9orf72 hexanucleotide repeat in DNA derived from lymphoblastoid cell lines. C9orf72 repeat expansions were found in 27.1% out of 166 familial ALS patients, only once in 68 sporadic ALS patients, and not in 61 hereditary spastic paraplegia patients or 52 patients with motor neuron diseases affecting clinically primarily either the first or the second motor neuron. We found hints for a correlation between C9orf72 repeat length and the age of onset. Somatic instability of the C9orf72 repeat was observed in lymphoblastoid cell lines compared with DNA derived from whole blood from the same patient and therefore caution is warranted for repeat length determination in immortalized cell lines.

  8. A simple DNA recombination screening method by RT-PCR as an alternative to Southern blot

    DEFF Research Database (Denmark)

    Albers, Eliene; Sbroggiò, Mauro; Martin Gonzalez, Javier

    2017-01-01

    The generation of genetically engineered mouse models (GEMMs), including knock-out (KO) and knock-in (KI) models, often requires genomic screening of many mouse ES cell (mESC) clones by Southern blot. The use of large targeting constructs facilitates the recombination of exogenous DNA in a specific...... that match exons flanking the targeting construct. The detection of the expected modification in this PCR product confirms the integration at the correct genomic location and shows that the mutant mRNA is expressed. This is a simple and sensitive strategy to screen locus-specific recombination of targeting...

  9. Design, preparation and use of ligated phosphoproteins: a novel approach to study protein phosphatases by dot blot array, ELISA and Western blot assays.

    Science.gov (United States)

    Sun, Luo; Ghosh, Inca; Barshevsky, Tanya; Kochinyan, Samvel; Xu, Ming-Qun

    2007-07-01

    The study of substrate specificity of protein phosphatases (PPs) is very challenging since it is difficult to prepare a suitable phosphorylated substrate. Phosphoproteins, phosphorylated by a protein kinase, or chemically synthesized phosphopeptides are commonly used substrates for PPs. Both types of these substrates have their advantages and limitations. Phosphoproteins mimic more closely the physiologically relevant PP substrates, but their preparation is technically demanding. Synthetic phosphopeptides present advantages over proteins because they can be easily produced in large quantity and their amino acid sequence can be designed to contain potential determinants of substrate specificity. However, short peptides are less optimal compared to in vivo PP substrates and often display poor and variable binding to different matrices, resulting in low sensitivity in analysis of PP activity on solid support. In this work we utilize the intein-mediated protein ligation (IPL) technique to generate substrates for PPs, combining the advantages of proteins and synthetic peptides in one molecule. The ligation of a synthetic phosphopeptide to an intein-generated carrier protein (CP) with a one-to-one stoichiometry results in the formation of a ligated phosphoprotein (LPP). Three widely used assays, dot blot array, Western blot and ELISA were employed to study the PP activity on LPP substrates. Dephosphorylation was measured by detection of the remaining phosphorylation, or lack of it, with a phospho-specific antibody. The data show the advantage of LPPs over free peptides in assays on solid supports. LPPs exhibited enhanced binding to the matrices used in the study, which significantly improved sensitivity and consistency of the assays. In addition, saturation of the signal was circumvented by serial dilution of the assay samples. This report describes detailed experimental procedures for preparation of LPP substrates and their use in PP assays based on immobilization on

  10. Different domains of Bacillus thuringiensis delta-endotoxins can bind to insect midgut membrane proteins on ligand blots

    NARCIS (Netherlands)

    Maagd, de R.A.; Klei, van der H.; Bakker, P.L.; Stiekema, W.J.; Bosch, D.

    1996-01-01

    We investigated the role of the constituent domains of the CryIA(b) and CryIA(c) δ-endotoxins in binding to midgut epithelial cell membrane proteins of Spodoptera exigua and Manduca sexta on ligand blots. A collection of wild- type and CryIC-CryIA hybrid toxins was used for this purpose. As demonstr

  11. A Technique for Designing Variation Resilient Subthreshold Sram Cell

    Directory of Open Access Journals (Sweden)

    Aminul Islam

    2013-04-01

    Full Text Available This paper presents a technique for designing a variability aware subthreshold SRAM cell. The architecture of the proposed cell is similar to the standard read-decoupled 8-transistor (RD8T SRAM cell with the exception that the access FETS are replaced with transmission gates (TGs. In this work, various design metrics are assessed and compared with RD8T SRAM cell. The proposed design offers 2.14× and 1.75× improvement in TRA (read access time and TWA (write access time respectively compared with RD8T. It proves its robustness against process variations by featuring narrower spread in TRA distribution (2.35× and TWA distribution (3.79× compared with RD8T. The proposed bitcell offers 1.16× higher read current (IREAD and 1.64× lower bitline leakage current (ILEAK respectively compared with RD8T. It also shows its robustness by offering 1.34× (1.58× tighter spread in IREAD (ILEAK compared with RD8T. It exhibits 1.42× larger IREAD to ILEAK ratio. It shows 2.2× higher frequency @ 250 mV with read bitline capacitance of 10 fF. Besides, the proposed bitcell achieves same read stability and write-ability as that of RD8T at the cost of 3 extra transistors. The leakage power of the proposed design is close to that of RD8T.   ABSTRAK: Kertas kerja ini membentangkan teknik merekabentuk sel bawah ambang SRAM yang bolehubah. Senibina sel yang dicadangkan adalah sama dengan sel SRAM 8-transistor (RD8T “pisahan-bacaan” piawai kecuali FET akses  digantikan dengan sel pintu transmisi (TGs. Di dalam kajian ini, beberapa metrik rekabentuk dinilai dan dibandingkan dengan sel RD8T SRAM. Rekabentuk yang dicadangkan menawarkan  peningkatan 2.14× dan 1.75×  dalam TRA (masa akses baca dan TWA (masa akses tulis berbanding dengan RD8T. Ia membuktikan kekukuhan variasi proses dengan menampilkan tebaran yang lebih sempit dalam pengagihan TRA (2.35 × dan pengagihan TWA (3.79 × berbanding dengan RD8T. Sel-Bit yang dicadangkan mempunyai arus baca 1.16

  12. A Novel Technique for Performing PID Susceptibility Screening during the Solar Cell Fabrication Process

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Jaewon; Dahal, Som; Dauksher, Bill; Bowden, Stuart; Tamizhmani, Govindasamy; Hacke, Peter

    2016-11-21

    Various characterization techniques have historically been developed in order to screen potential induced degradation (PID)-susceptible cells, but those techniques require final solar cells. We present a new characterization technique for screening PID-susceptible cells during the cell fabrication process. Illuminated Lock-In Thermography (ILIT) was used to image PID shunting of the cell without metallization and clearly showed PID-affected areas. PID-susceptible cells can be screened by ILIT, and the sample structure can advantageously be simplified as long as the sample has the silicon nitride antireflection coating and an aluminum back surface field.

  13. A simple DNA recombination screening method by RT-PCR as an alternative to Southern blot.

    Science.gov (United States)

    Albers, Eliene; Sbroggiò, Mauro; Martin-Gonzalez, Javier; Avram, Alexandra; Munk, Stephanie; Lopez-Contreras, Andres J

    2017-01-19

    The generation of genetically engineered mouse models (GEMMs), including knock-out (KO) and knock-in (KI) models, often requires genomic screening of many mouse ES cell (mESC) clones by Southern blot. The use of large targeting constructs facilitates the recombination of exogenous DNA in a specific genomic locus, but limits the detection of its correct genomic integration by standard PCR methods. Genomic Long Range PCR (LR-PCR), using primers adjacent to the homology arms, has been used as an alternative to radioactive-based Southern blot screenings. However, LR-PCRs are often difficult and render many false positive and false negative results. Here, we propose an alternative screening method based on the detection of a genetic modification at the mRNA level, which we successfully optimized in two mouse models. This screening method consists of a reverse-transcription PCR (RT-PCR) using primers that match exons flanking the targeting construct. The detection of the expected modification in this PCR product confirms the integration at the correct genomic location and shows that the mutant mRNA is expressed. This is a simple and sensitive strategy to screen locus-specific recombination of targeting constructs which can also be useful to screen KO and KI mutant mice or cell lines including those generated by CRISPR/Cas9.

  14. Rapid detection and differentiation of important Campylobacter spp. in poultry samples by dot blot and PCR.

    Science.gov (United States)

    Fontanot, Marco; Iacumin, Lucilla; Cecchini, Francesca; Comi, Giuseppe; Manzano, Marisa

    2014-10-01

    The detection of Campylobacter, the most commonly reported cause of foodborne gastroenteritis in the European Union, is very important for human health. The most commonly recognised risk factor for infection is the handling and/or consumption of undercooked poultry meat. The methods typically applied to evaluate the presence/absence of Campylobacter in food samples are direct plating and/or enrichment culture based on the Horizontal Method for Detection and Enumeration of Campylobacter spp. (ISO 10272-1B: 2006) and PCR. Molecular methods also allow for the detection of cells that are viable but cannot be cultivated on agar media and that decrease the time required for species identification. The current study proposes the use of two molecular methods for species identification: dot blot and PCR. The dot blot method had a sensitivity of 25 ng for detection of DNA extracted from a pure culture using a digoxigenin-labelled probe for hybridisation; the target DNA was extracted from the enrichment broth at 24 h. PCR was performed using a pair of sensitive and specific primers for the detection of Campylobacter jejuni and Campylobacter coli after 24 h of enrichment in Preston broth. The initial samples were contaminated by 5 × 10 C. jejuni cells/g and 1.5 × 10(2)C. coli cells/g, thus the number of cells present in the enrichment broth at 0 h was 1 or 3 cell/g, respectively.

  15. An effective technique for isolating adult activated Schwann cells

    Institute of Scientific and Technical Information of China (English)

    Jifei Zhang; Lianhong Jin; Yuzhen Zhao

    2006-01-01

    BACKGROUND: Schwann cells (SCs) are neuroglial cells of peripheral nerve and play a key role in repairing peripheral nerve injury; therefore, it provides an important evidence for transplantation of SCs which are characterized by active proliferation and adult high-purity in vitro after nerve injury in clinic, and also develops a new therapeutic way for nerve injury.OBJECTIVE: To investigate an effective technique for isolating adult activated Schwann cells.DESIGN: Controlled observational study.SETTING: Mudanjiang Medical College.MATERIALS: The experiment was completed at the Department of Medical Genetics of Harbin Medical University from March 2003 to April 2005. Health female Wistar rats, aged 2 months, weighting 150-160 g, were randomly divided into 3 groups with 5 in each group.METHODS: The right sciatic nerves from 15 Wistar rats were exposed and transected at the mid thigh under pentobarbital anesthesia (4 mg/kg, I.p). Seven days later, the distal segments of the predegenerated nerves were removed and used to produce adult Schwann cell cultures. The distal segment of the predegenerated nerve, 20 mm in length, was resected. The nerve was cut into pieces 1 mm in length and incubated for 3 hours under CO2 at 37 ℃ with an enzyme mixture of 0.05% collagenase/dispase. Rats were divided into 3 groups:① Group 1: The nerve fragments were explanted in poly-L-lysine and laminin-coated dishes with BS medium from the 1st to the 6th day. On the 6th day, the fragments were removed into a new poly-L-lysine-laminin-coated dish and the BS medium was changed to BS with 10% FBS. The nerve fragments were replaced repeatedly in the same way in new dishes on the 12th and the 18th days. ②Group 2: For the first 3 days, the nerve fragments were fed with BS with 10% FBS. This medium was changed to BS medium on the third day. The nerve fragments were removed to another dish on day 6 and BS medium was changed to BS with 25 mL/L FBS. Hereafter the culture method was the same as

  16. Experimental methods and modeling techniques for description of cell population heterogeneity

    NARCIS (Netherlands)

    Fernandes, R. Lencastre; Nierychlo, M.; Lundin, L.; Pedersen, A. E.; Puentes Téllez, Pilar; Dutta, A.; Carlquist, M.; Bolic, A.; Schapper, D.; Brunetti, A. C.; Helmark, S.; Heins, A. -L; Jensen, A. D.; Nopens, I.; Rottwitt, K.; Szita, N.; van Elsas, J. D.; Nielsen, P. H.; Martinussen, J.; Sorensen, S. J.; Lantz, A. E.; Gernaey, K. V.

    2011-01-01

    With the continuous development, in the last decades, of analytical techniques providing complex information at single cell level, the study of cell heterogeneity has been the focus of several research projects within analytical biotechnology. Nonetheless, the complex interplay between environmental

  17. Experimental methods and modeling techniques for description of cell population heterogeneity

    DEFF Research Database (Denmark)

    Lencastre Fernandes, Rita; Nierychlo, M.; Lundin, L.

    2011-01-01

    With the continuous development, in the last decades, of analytical techniques providing complex information at single cell level, the study of cell heterogeneity has been the focus of several research projects within analytical biotechnology. Nonetheless, the complex interplay between environmen...

  18. Gel electrophoresis of polyphenol oxidase with instant identification by in situ blotting.

    Science.gov (United States)

    Cheng, Tsai-Mu; Huang, Pei-Chen; Pan, Ju-Pin; Lin, Kuan-Yu; Mao, Simon J T

    2007-04-15

    Polyphenol oxidase (PPO) or tyrosinase is an important and ubiquitous enzyme responsible for browning in plants and melanization in animals. The molecular size of the plant PPO is varied among the species and its activity can be enhanced by a variety of anionic detergents. In the present study, we developed a simple method for the first-step identification of PPO in fruit and vegetable extracts. First, 3mm chromatographic paper was immersed in 0.5% (w/v) catechol solution as an immobilized PPO substrate. After running the extract with 10% sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), one side of the glass plate was removed. The plate was immediately laid on top of the dried catechol-paper. A dark-brown band corresponding to PPO was visualized within 1 min and was further confirmed by a conventional Western blot using an antibody prepared against mushroom PPO. It also reveals that some vegetation (such as tomato, radish, and oriental melon) with low or no detectable activity in a conventional enzyme assay actually possessed marked levels of PPO activity when assessed by PAGE-blot. We propose that an inhibitor is associated with PPO in some plants; the inhibitor, however, is dissociated during the electrophoresis. Therefore, in addition to identify the molecular form of PPO, the present technique may explore the existence of PPO inhibitor(s) in plants. The detail of the method with respect to its relevance for searching a natural PPO inhibitor is described and discussed.

  19. Optical diffraction tomography techniques for the study of cell pathophysiology

    CERN Document Server

    Kim, Kyoohyun; Shin, Seungwoo; Lee, SangYun; Yang, Su-A; Park, YongKeun

    2016-01-01

    Three-dimensional imaging of biological cells is crucial for the investigation of cell biology, provide valuable information to reveal the mechanisms behind pathophysiology of cells and tissues. Recent advances in optical diffraction tomography (ODT) have demonstrated the potential for the study of various cells with its unique advantages of quantitative and label-free imaging capability. To provide insight on this rapidly growing field of research and to discuss its applications in biology and medicine, we present the summary of the ODT principle and highlight recent studies utilizing ODT with the emphasis on the applications to the pathophysiology of cells.

  20. Biotechnology Apprenticeship for Secondary-Level Students: Teaching Advanced Cell Culture Techniques for Research.

    Science.gov (United States)

    Lewis, Jennifer R.; Kotur, Mark S.; Butt, Omar; Kulcarni, Sumant; Riley, Alyssa A.; Ferrell, Nick; Sullivan, Kathryn D.; Ferrari, Mauro

    2002-01-01

    Discusses small-group apprenticeships (SGAs) as a method for introducing cell culture techniques to high school participants. Teaches cell culture practices and introduces advance imaging techniques to solve various biomedical engineering problems. Clarifies and illuminates the value of small-group laboratory apprenticeships. (Author/KHR)

  1. Nondestructive cell evaluation techniques in SOFC stack manufacturing

    Science.gov (United States)

    Wunderlich, C.

    2016-04-01

    Independent from the specifics of the application, a cost efficient manufacturing of solid oxide fuel cells (SOFC), its electrolyte membranes and other stack components, leading to reliable long-life stacks is the key for the commercial viability of this fuel cell technology. Tensile and shear stresses are most critical for ceramic components and especially for thin electrolyte membranes as used in SOFC cells. Although stack developers try to reduce tensile stresses acting on the electrolyte by either matching CTE of interconnects and electrolytes or by putting SOFC cells under some pressure - at least during transient operation of SOFC stacks ceramic cells will experience some tensile stresses. Electrolytes are required to have a high Weibull characteristic fracture strength. Practical experiences in stack manufacturing have shown that statistical fracture strength data generated by tests of electrolyte samples give limited information on electrolyte or cell quality. In addition, the cutting process of SOFC electrolytes has a major influence on crack initiation. Typically, any single crack in one the 30 to 80 cells in series connection will lead to a premature stack failure drastically reducing stack service life. Thus, for statistical reasons only 100% defect free SOFC cells must be assembled in stacks. This underlines the need for an automated inspection. So far, only manual processes of visual or mechanical electrolyte inspection are established. Fraunhofer IKTS has qualified the method of optical coherence tomography for an automated high throughput inspection. Alternatives like laser speckle photometry and acoustical methods are still under investigation.

  2. New technique for needle-less implantation of eukaryotic cells

    NARCIS (Netherlands)

    Silva, L.F. Arenas da; Schober, L.; Sloff, M.; Traube, A.; Hart, M.L.; Feitz, W.F.J.; Stenzl, A.

    2015-01-01

    BACKGROUND AIMS: On review of the use of stem cells in the literature, promissory outcomes for functional organ recovery in many subspecialties in medicine underscore its therapeutic potential. The application of stem cells through the use of a needle can result in additional scar formation, which i

  3. Optical Trapping Techniques Applied to the Study of Cell Membranes

    Science.gov (United States)

    Morss, Andrew J.

    Optical tweezers allow for manipulating micron-sized objects using pN level optical forces. In this work, we use an optical trapping setup to aid in three separate experiments, all related to the physics of the cellular membrane. In the first experiment, in conjunction with Brian Henslee, we use optical tweezers to allow for precise positioning and control of cells in suspension to evaluate the cell size dependence of electroporation. Theory predicts that all cells porate at a transmembrane potential VTMof roughly 1 V. The Schwann equation predicts that the transmembrane potential depends linearly on the cell radius r, thus predicting that cells should porate at threshold electric fields that go as 1/r. The threshold field required to induce poration is determined by applying a low voltage pulse to the cell and then applying additional pulses of greater and greater magnitude, checking for poration at each step using propidium iodide dye. We find that, contrary to expectations, cells do not porate at a constant value of the transmembrane potential but at a constant value of the electric field which we find to be 692 V/cm for K562 cells. Delivering precise dosages of nanoparticles into cells is of importance for assessing toxicity of nanoparticles or for genetic research. In the second experiment, we conduct nano-electroporation—a novel method of applying precise doses of transfection agents to cells—by using optical tweezers in conjunction with a confocal microscope to manipulate cells into contact with 100 nm wide nanochannels. This work was done in collaboration with Pouyan Boukany of Dr. Lee's group. The small cross sectional area of these nano channels means that the electric field within them is extremely large, 60 MV/m, which allows them to electrophoretically drive transfection agents into the cell. We find that nano electroporation results in excellent dose control (to within 10% in our experiments) compared to bulk electroporation. We also find that

  4. Advanced characterization techniques for thin film solar cells

    CERN Document Server

    Rau, Uwe; Kirchartz, Thomas

    2011-01-01

    Written by scientists from leading institutes in Germany, USA and Spain who use these techniques as the core of their scientific work and who have a precise idea of what is relevant for photovoltaic devices, this text contains concise and comprehensive lecture-like chapters on specific research methods.They focus on emerging, specialized techniques that are new to the field of photovoltaics yet have a proven relevance. However, since new methods need to be judged according to their implications for photovoltaic devices, a clear introductory chapter describes the basic physics of thin-film

  5. NucleoCounter—An efficient technique for the determination of cell number and viability in animal cell culture processes

    OpenAIRE

    Shah, Dimpalkumar; Naciri, Mariam; Clee, Paul; Al-Rubeai, Mohamed

    2006-01-01

    The NucleoCounter is a novel, portable cell counting device based on the principle of fluorescence microscopy. The present work establishes its use with animal cells and checks its reliability, consistency and accuracy in comparison with other cytometric techniques. The main advantages of this technique are its ability to handle a large number of samples with a high degree of precision and its simplicity and specificity in detecting viable cells quantitatively in a heterogeneous culture. The ...

  6. Sparse grid techniques for particle-in-cell schemes

    Science.gov (United States)

    Ricketson, L. F.; Cerfon, A. J.

    2017-02-01

    We propose the use of sparse grids to accelerate particle-in-cell (PIC) schemes. By using the so-called ‘combination technique’ from the sparse grids literature, we are able to dramatically increase the size of the spatial cells in multi-dimensional PIC schemes while paying only a slight penalty in grid-based error. The resulting increase in cell size allows us to reduce the statistical noise in the simulation without increasing total particle number. We present initial proof-of-principle results from test cases in two and three dimensions that demonstrate the new scheme’s efficiency, both in terms of computation time and memory usage.

  7. Chikungunya virus isolation using simplified cell culture technique in Mauritius.

    Science.gov (United States)

    Pyndiah, M N; Pursem, V; Meetoo, G; Daby, S; Ramuth, V; Bhinkah, P; Chuttoo, R; Paratian, U

    2012-03-01

    During the chikungunya outbreak of 2005 - 2006, the only laboratory facilities available in Mauritius were virus isolation in cell culture tubes and serology. The laboratory was submerged with large numbers of blood samples. Comparative isolation was made in human embryonic lung (HEL) and VERO cells grown in 96-well plate. Culture on HEL cells was found to be more sensitive and presence of cytopathic effect (CPE) was observed earlier than in VERO cells. Out of the 18 300 blood samples inoculated on HEL, 11 165 were positive. This virus isolation method was of great help for the surveillance and control of the vectors. In cases of an outbreak a cheap, rapid and simple method of isolating chikungunya virus is described.

  8. Technique for Outdoor Test on Concentrating Photovoltaic Cells

    Directory of Open Access Journals (Sweden)

    Paola Sansoni

    2015-01-01

    Full Text Available Outdoor experimentation of solar cells is essential to maximize their performance and to assess utilization requirements and limits. More generally tests with direct exposure to the sun are useful to understand the behavior of components and new materials for solar applications in real working conditions. Insolation and ambient factors are uncontrollable but can be monitored to know the environmental situation of the solar exposure experiment. A parallel characterization of the photocells can be performed in laboratory under controllable and reproducible conditions. A methodology to execute solar exposure tests is proposed and practically applied on photovoltaic cells for a solar cogeneration system. The cells are measured with concentrated solar light obtained utilizing a large Fresnel lens mounted on a sun tracker. Outdoor measurements monitor the effects of the exposure of two multijunction photovoltaic cells to focused sunlight. The main result is the continuous acquisition of the V-I (voltage-current curve for the cells in different conditions of solar concentration and temperature of exercise to assess their behavior. The research investigates electrical power extracted, efficiency, temperatures reached, and possible damages of the photovoltaic cell.

  9. "Humanized" stem cell culture techniques: the animal serum controversy.

    Science.gov (United States)

    Tekkatte, Chandana; Gunasingh, Gency Ponrose; Cherian, K M; Sankaranarayanan, Kavitha

    2011-01-01

    Cellular therapy is reaching a pinnacle with an understanding of the potential of human mesenchymal stem cells (hMSCs) to regenerate damaged tissue in the body. The limited numbers of these hMSCs in currently identified sources, like bone marrow, adipose tissue, and so forth, bring forth the need for their in vitro culture/expansion. However, the extensive usage of supplements containing xenogeneic components in the expansion-media might pose a risk to the post-transplantation safety of patients. This warrants the necessity to identify and develop chemically defined or "humanized" supplements which would make in vitro cultured/processed cells relatively safer for transplantation in regenerative medicine. In this paper, we outline the various caveats associated with conventionally used supplements of xenogenic origin and also portray the possible alternatives/additives which could one day herald the dawn of a new era in the translation of in vitro cultured cells to therapeutic interventions.

  10. Stem cell clonality -- theoretical concepts, experimental techniques, and clinical challenges.

    Science.gov (United States)

    Glauche, Ingmar; Bystrykh, Leonid; Eaves, Connie; Roeder, Ingo

    2013-04-01

    Here we report highlights of discussions and results presented at an International Workshop on Concepts and Models of Stem Cell Organization held on July 16th and 17th, 2012 in Dresden, Germany. The goal of the workshop was to undertake a systematic survey of state-of-the-art methods and results of clonality studies of tissue regeneration and maintenance with a particular emphasis on the hematopoietic system. The meeting was the 6th in a series of similar conceptual workshops, termed StemCellMathLab,(2) all of which have had the general objective of using an interdisciplinary approach to discuss specific aspects of stem cell biology. The StemCellMathLab 2012, which was jointly organized by the Institute for Medical Informatics and Biometry, Medical Faculty Carl Gustav Carus, Dresden University of Technology and the Institute for Medical Informatics, Statistics and Epidemiology, Medical Faculty, University of Leipzig, brought together 32 scientists from 8 countries, with scientific backgrounds in medicine, cell biology, virology, physics, computer sciences, bioinformatics and mathematics. The workshop focused on the following questions: (1) How heterogeneous are stem cells and their progeny? and (2) What are the characteristic differences in the clonal dynamics between physiological and pathophysiological situations? In discussing these questions, particular emphasis was placed on (a) the methods for quantifying clones and their dynamics in experimental and clinical settings and (b) general concepts and models for their description. In this workshop summary we start with an introduction to the current state of clonality research and a proposal for clearly defined terminology. Major topics of discussion include clonal heterogeneity in unperturbed tissues, clonal dynamics due to physiological and pathophysiological pressures and conceptual and technical issues of clone quantification. We conclude that an interactive cross-disciplinary approach to research in this

  11. NORTHERN BLOT ANALYSIS OF nm23 GENE EXPRESSION IN HUMAN LUNG CANCER

    Institute of Scientific and Technical Information of China (English)

    LIU Lun-xu; ZHOU Qing-hua; SHI Ying-kang; QIN Yang; SUN Zhi-lin; SUN Ze-fang

    1999-01-01

    Objective: To investigate the role of nm23 gene expression in human lung cancer. Methods: Forty human lung cancer tissues and 19 non-cancer pulmonary tissues were studied for their nm23-H1 and nm23-H2 mRNA expression with non-radioactive Northern blot hybridization. The correlation of nm23 mRNA expression with clinical features of lung cancer was analyzed. Results: The mRNA expression of nm23-H2 gene in poorly differentiated squamous cell carcinoma was significantly decreased compared to that in moderate-high differentiated squamous cell carcinoma. The mRNA expression of nm23-H1 and nm23-H2 gene in small cell lung cancer was significantly decreased compared to that in squamous cell carcinoma. No significant difference in nm23 mRNA expression was observed between lung cancer with and without lymph node metastasis, nor was there significant difference between tumor stage. Conclusion: The mRNA expression of nm23 gene is correlated with the degree of differentiation of lung cancer, but there is no evidence of metastasis suppression effect by nm23 gene.

  12. Application of a Dot Blot Hybridization Platform to Assess Streptococcus uberis Population Structure in Dairy Herds

    Science.gov (United States)

    Albuquerque, Pedro; Ribeiro, Niza; Almeida, Alexandre; Panschin, Irena; Porfirio, Afonso; Vales, Marta; Diniz, Francisca; Madeira, Helena; Tavares, Fernando

    2017-01-01

    Streptococcus uberis is considered one of the most important pathogens associated with bovine mastitis. While traditionally acknowledged as an environmental pathogen, S. uberis has been shown to adopt a contagious epidemiological pattern in several dairy herds. Since different control strategies are employed depending on the mode of transmission, in-depth studies of S. uberis populations are essential to determine the best practices to control this pathogen. In this work, we optimized and validated a dot blot platform, combined with automatic image analysis, to rapidly assess the population structure of infective S. uberis, and evaluated its efficiency when compared to multilocus sequence analysis (MLSA) genotyping. Two dairy herds with prevalent S. uberis infections were followed in a 6 month period, in order to collect and characterize isolates from cows with persistent infections. These herds, located in Portugal (Barcelos and Maia regions), had similar management practices, with the herd from Barcelos being smaller and having a better milking parlor management, since infected cow segregation was immediate. A total of 54 S. uberis isolates were obtained from 24 different cows from the two herds. To overcome operator-dependent analysis of the dot blots and increase the technique's consistency and reliability, the hybridization signals were converted into probability values, with average probabilities higher than 0.5 being considered positive results. These data allowed to confirm the isolates' identity as S. uberis using taxa-specific markers and to determine the presence of virulence- and antibiotic resistance-related genes. In addition, MLSA allowed to disclose the most prevalent S. uberis clonal lineages in both herds. Seven different clusters were identified, with Barcelos showing a high clonal diversity and Maia a dominant lineage infecting most cows, suggesting distinct epidemiological patterns, with S. uberis displaying an environmental or contagious

  13. Stem cell clonality - Theoretical concepts, experimental techniques, and clinical challenges

    NARCIS (Netherlands)

    Glauche, Ingmar; Bystrykh, Leonid; Eaves, COnnie; Roeder, Ingo

    2013-01-01

    Here we report highlights of discussions and results presented at an International Workshop on Concepts and Models of Stem Cell Organization held on July 16th and 17th, 2012 in Dresden, Germany. The goal of the workshop was to undertake a systematic survey of state-of-the-art methods and results of

  14. Total protein analysis as a reliable loading control for quantitative fluorescent Western blotting.

    Directory of Open Access Journals (Sweden)

    Samantha L Eaton

    Full Text Available Western blotting has been a key technique for determining the relative expression of proteins within complex biological samples since the first publications in 1979. Recent developments in sensitive fluorescent labels, with truly quantifiable linear ranges and greater limits of detection, have allowed biologists to probe tissue specific pathways and processes with higher resolution than ever before. However, the application of quantitative Western blotting (QWB to a range of healthy tissues and those from degenerative models has highlighted a problem with significant consequences for quantitative protein analysis: how can researchers conduct comparative expression analyses when many of the commonly used reference proteins (e.g. loading controls are differentially expressed? Here we demonstrate that common controls, including actin and tubulin, are differentially expressed in tissues from a wide range of animal models of neurodegeneration. We highlight the prevalence of such alterations through examination of published "-omics" data, and demonstrate similar responses in sensitive QWB experiments. For example, QWB analysis of spinal cord from a murine model of Spinal Muscular Atrophy using an Odyssey scanner revealed that beta-actin expression was decreased by 19.3±2% compared to healthy littermate controls. Thus, normalising QWB data to β-actin in these circumstances could result in 'skewing' of all data by ∼20%. We further demonstrate that differential expression of commonly used loading controls was not restricted to the nervous system, but was also detectable across multiple tissues, including bone, fat and internal organs. Moreover, expression of these "control" proteins was not consistent between different portions of the same tissue, highlighting the importance of careful and consistent tissue sampling for QWB experiments. Finally, having illustrated the problem of selecting appropriate single protein loading controls, we demonstrate

  15. Photovoltaic Cell Fed 3-Phase Induction Motor Using MPPT Technique

    Directory of Open Access Journals (Sweden)

    Gudimetla Ramesh

    2014-10-01

    Full Text Available This Paper emphasizes on proposing a cost effective photovoltaic (PV fed 3 phase Induction motor drive which serves for rural pumping applications. Generally in a standalone system, the PV unit will charge the battery and the battery set up in turn will serve as a source for the inverter. A new single stage battery less power conversion is employed by designing a maximum power point tracker (MPPT embedded boost converter which makes the overall cost of the setup to go down considerably. The realized as a prototype consisting PV array of 500watts, MPPT aided boost converter, three phase inverter and a three phase squirrel cage induction drive of 300 watts. An efficient and low cost micro controller dspic4011 is used a platform to code and implement the prominent perturb and observe MPPT technique .Sinusoidal pulse width modulation (SPWM is the  control technique employed for  the three phase  inverter. To validate the experimental results simulation of the whole set up is carried out in matlab /simulink environment. Simulation and hardware results reveal that the system is versatile.

  16. RNase protection assays and RNA gel blots: a direct comparison of sensitivity.

    Science.gov (United States)

    Higgs, D C; Colbert, J T

    1992-01-01

    RNase protection assays are commonly thought to be a more sensitive means of detecting and quantitating specific mRNAs than are RNA gel blots (Northern blots). We have directly compared the sensitivity of these two approaches by assaying for known amounts of in vitro synthesized beta-glucuronidase mRNA. With the probes and protocols employed here, the ability to detect a specific mRNA was similar whether RNase protection or RNA gel blot analyses were performed.

  17. A simple dot-blot-Sirius red-based assay for collagen quantification.

    Science.gov (United States)

    Rodríguez-Rodríguez, Pilar; Arribas, Silvia M; de Pablo, Angel Luis López; González, M Carmen; Abderrahim, Fatima; Condezo-Hoyos, Luis

    2013-08-01

    The assessment of collagen content in tissues is important in biomedical research, since this protein is altered in numerous diseases. Hydroxyproline and Sirius red based assays are the most common methods for collagen quantification. However, these procedures have some pitfalls, such as the requirement of oxygen-free medium or expensive equipment and large sample size or being unsuitable for hydrolyzed collagen, respectively. Our objective was to develop a specific, versatile, and user-friendly quantitative method applicable to small tissue samples and extracts obtained from elastin purification, therefore, suitable for simultaneous quantification of elastin. This method is based on the binding of Sirius red to collagen present in a sample immobilized on a PVDF membrane, as in the dot-blot technique, and quantified by a scanner and image analysis software. Sample loading, Sirius red concentration, temperature and incubation time, type of standard substance, albumin interference, and quantification time are optimized. The method enabled the quantification of (1) intact collagen in several rat tissue homogenates, including small resistance-sized arteries, (2) partially hydrolyzed collagen obtained from NaOH extracts, compatible with elastin purification, and (3) for the detection of differences in collagen content between hypertensive and normotensive rats. We conclude that the developed technique can be widely used since it is versatile (quantifies intact and hydrolyzed collagen), requires small sample volumes, is user-friendly (low-cost, easy to use, minimum toxic materials, and reduced time of test), and is specific (minimal interference with serum albumin).

  18. Western blot diagnosis of vivax malaria with multiple stage-specific antigens of the parasite.

    Science.gov (United States)

    Son, E S; Kim, T S; Nam, H W

    2001-06-01

    Western blot analysis was performed to diagnose vivax malaria using stage-specific recombinant antigens. Genomic DNA from the whole blood of a malaria patient was used as templates to amplify the coding regions for the antigenic domains of circumsporozoite protein (CSP-1), merozoite surface protein (MSP-1), apical merozoite antigen (AMA-1), serine repeat antigen (SERA), and exported antigen (EXP-1) of Plasmodium vivax. Each amplified DNA fragment was inserted into a pGEX-4T plasmid to induce the expression of GST fusion protein in Escherichia coli by IPTG. The bacterial cell extracts were separated on 10% SDS-PAGE followed by western blot analysis with patient sera which was confirmed by blood smear examination. When applied with patient sera, 147 (91.9%) out of 160 vivax malaria, 12 (92.3%) out of 13 falciparum malaria, and all 9 vivax/falciparum mixed malaria reacted with at least one antigen, while no reactions occurred with 20 normal uninfected sera. In the case of vivax malaria, CSP-1 reacted with 128 (80.0%) sera, MSP-1 with 102 (63.8%), AMA-1 with 128 (80.0%), SERA with 115 (71.9%), and EXP-1 with 89 (55.6%), respectively. We obtained higher detection rates when using 5 antigens (91.9%) rather than using each antigen solely (55.6-80%), a combination of 2 (76.3-87.5%), 3 (85.6-90.6%), or 4 antigens (89.4-91.3%). This method can be applied to serological diagnosis, mass screening in endemic regions, or safety test in transfusion of prevalent vivax malaria.

  19. Quantitative Phase Imaging Techniques for the Study of Cell Pathophysiology: From Principles to Applications

    Directory of Open Access Journals (Sweden)

    Hyunjoo Park

    2013-03-01

    Full Text Available A cellular-level study of the pathophysiology is crucial for understanding the mechanisms behind human diseases. Recent advances in quantitative phase imaging (QPI techniques show promises for the cellular-level understanding of the pathophysiology of diseases. To provide important insight on how the QPI techniques potentially improve the study of cell pathophysiology, here we present the principles of QPI and highlight some of the recent applications of QPI ranging from cell homeostasis to infectious diseases and cancer.

  20. Application of the wavelet image analysis technique to monitor cell concentration in bioprocesses

    Directory of Open Access Journals (Sweden)

    G. J. R. Garófano

    2005-12-01

    Full Text Available The growth of cells of great practical interest, such as, the filamentous cells of bacterium Streptomyces clavuligerus, the yeast Saccharomyces cerevisiae and the insect Spodoptera frugiperda (Sf9 cell, cultivated in shaking flasks with complex media at appropriate temperatures and pHs, was quantified by the new wavelet transform technique. This image analysis tool was implemented using Matlab 5.2 software to process digital images acquired of samples taken of these three types of cells throughoot their cultivation. The values of the average wavelet coefficients (AWCs of simplified images were compared with experimental measurements of cell concentration and with computer-based densitometric measurements. AWCs were shown to be directly proportional to measurements of cell concentration and to densitometric measurements, making evident the great potential of the wavelet transform technique to quantitatively estimate the growth of several types of cells.

  1. Experimental Verification of Interference Mitigation Techniques for 5G Small Cells

    DEFF Research Database (Denmark)

    Assefa, Dereje; Berardinelli, Gilberto; Tavares, Fernando Menezes Leitão;

    2015-01-01

    deployment with four cells, where each cell features one Access Point (AP) and one User Equipment (UE). In particular, we compare traditional Frequency Reuse Planning (FRP) with the recently proposed Maximum Rank Planning (MRP) technique, which relies on the degrees of freedom offered by the multi......Inter-cell interference is the main performance limiting factor in the dense deployment of small cells targeted by the upcoming 5th Generation (5G) radio access technology. In this paper, we present an experimental evaluation of inter-cell interference mitigation techniques in a real indoor office...... with the USRP N200 hardware by Ettus Research. The experimental results in a fully loaded network reveal the capability of the MRP technique to achieve higher throughput performance than FRP for 90% of the cases when IRC receivers are used. Lower network loads lead to further performance improvements for MRP....

  2. Evaluation of an indigenous western blot kit for human immunodeficiency virus

    Directory of Open Access Journals (Sweden)

    Lakshmi V

    2002-01-01

    Full Text Available PURPOSE: The Western Blot test is considered a gold standard test for the confirmation of an ELISA and/or rapid assay screened reactive sample in the diagnosis of HIV infection, especially in the low risk population. In this study, an indigenously developed HIV W. Blot kit (J.Mitra & Co., New Delhi, India was compared for its performance characteristics with a widely used Western Blot kit, HIV Blot 2.2 (Genelabs, Singapore. Antigens of both HIV-1 and the indicator antigen gp36 of HIV-2 are included in the strips. METHODS: A panel of 150 clinical serum samples was used in the evaluation. All the sera were tested simultaneously by both the kits. RESULTS: The HIV W. Blot kit had high performance characteristics (100% sensitivity and 100% specificity, like the HIV Blot 2.2. The test procedure was easy to perform. There was clear delineation of the bands. CONCLUSIONS: The interpretation of the results on the HIV W. Blot was less prone to subjective errors. The test gave positive bands at even very high serum dilutions in the test kit. This fact indicates that HIV W. Blot probably has a potential application in early phases of infection, when the antibody concentrations are still very low.

  3. Two dimensional numerical simulation of gas discharges: comparison between particle-in-cell and FCT techniques

    Energy Technology Data Exchange (ETDEWEB)

    Soria-Hoyo, C; Castellanos, A [Departamento de Electronica y Electromagnetismo, Facultad de Fisica, Universidad de Sevilla, Avda. Reina Mercedes s/n, 41012 Sevilla (Spain); Pontiga, F [Departamento de Fisica Aplicada II, EUAT, Universidad de Sevilla, Avda. Reina Mercedes s/n, 41012 Sevilla (Spain)], E-mail: cshoyo@us.es

    2008-10-21

    Two different numerical techniques have been applied to the numerical integration of equations modelling gas discharges: a finite-difference flux corrected transport (FD-FCT) technique and a particle-in-cell (PIC) technique. The PIC technique here implemented has been specifically designed for the simulation of 2D electrical discharges using cylindrical coordinates. The development and propagation of a streamer between two parallel electrodes has been used as a convenient test to compare the performance of both techniques. In particular, the phase velocity of the cathode directed streamer has been used to check the internal consistency of the numerical simulations. The results obtained from the two techniques are in reasonable agreement with each other, and both techniques have proved their ability to follow the high gradients of charge density and electric field present in this type of problems. Moreover, the streamer velocities predicted by the simulation are in accordance with the typical experimental values.

  4. Fabrication and processing of polymer solar cells: A review of printing and coating techniques

    DEFF Research Database (Denmark)

    Krebs, Frederik C

    2009-01-01

    -forming techniques such as slot-die coating, gravure coating, knife-over-edge coating, off-set coating, spray coating and printing techniques such as ink jet printing, pad printing and screen printing. The former are used almost exclusively and are not suited for high-volume production whereas the latter are highly...... suited, but little explored in the context of polymer solar cells. A further distinction is made between printing and coating when a film is formed. The entire process leading to polymer solar cells is broken down into the individual steps and the available techniques and materials for each step...

  5. The mouse prostaglandin E receptor EP2 subtype: cloning, expression, and northern blot analysis.

    Science.gov (United States)

    Katsuyama, M; Nishigaki, N; Sugimoto, Y; Morimoto, K; Negishi, M; Narumiya, S; Ichikawa, A

    1995-09-25

    A functional cDNA clone for the mouse prostaglandin (PG) E receptor EP2 subtype was isolated from a mouse cDNA library. The mouse EP2 receptor consists of 362 amino acid residues with seven putative transmembrane domains. [3H]PGE2 bound specifically to the membrane of Chinese hamster ovary cells stably expressing the cloned receptor. This binding was displaced by unlabeled prostanoids in the order of PGE2 = PGE1 > iloprost, a stable PGI2 agonist > PGF2 alpha > PGD2. Binding was also inhibited by butaprost (an EP2 agonist) and to a lesser extent by M&B 28767 (an EP3 agonist), but not by sulprostone (an EP1 and EP3 agonist) or SC-19220 (an EP1 antagonist). PGE2 and butaprost increased the cAMP level in the Chinese hamster ovary cells in a concentration-dependent manner. Northern blot analysis revealed that EP2 mRNA is expressed most abundantly in the uterus, followed by the spleen, lung, thymus, ileum, liver, and stomach.

  6. Investigation of Anti-Toxocara Antibodies in Epileptic Patients and Comparison of Two Methods: ELISA and Western Blotting

    Directory of Open Access Journals (Sweden)

    Mohammad Zibaei

    2013-01-01

    Full Text Available The relationship between Toxocara infection and epilepsy was previously demonstrated by several case-control studies and case reports. These previous studies were often based on the enzyme-linked immunosorbent assay (ELISA using Toxocara excretory-secretory antigens, which are not specific due to cross-reactivity with other parasitic infections such as ascariasis, trichuriasis, and anisakiasis. An immunoblot analysis is highly specific and can detect low levels of Toxocara antibodies. Therefore, this assay may be useful in the identification of toxocariasis in epileptic patients. We examined patients who had epilepsy and healthy subjects for seropositivity for Toxocara infection by ELISA and Western blotting. Out of 85 epileptic patients, 10 (11.8% and 3 (3.5% persons exhibited Toxocara immunoglobulin G (IgG antibodies responses by ELISA and by both techniques, respectively. Moreover, in the healthy group (, 3 (3.5% persons were positive by ELISA, but none was detected by Western blotting. This study indicates that Toxocara infection is a risk factor for epilepsy in Iran. These findings strongly suggest the need to perform Western blotting immunodiagnosis, as well as the ELISA using Toxocara excretory-secretory antigens, to improve diagnosis of human toxocariasis in patients with epilepsy.

  7. Biophysical Techniques for Detection of cAMP and cGMP in Living Cells

    Directory of Open Access Journals (Sweden)

    Viacheslav O. Nikolaev

    2013-04-01

    Full Text Available Cyclic nucleotides cAMP and cGMP are ubiquitous second messengers which regulate myriads of functions in virtually all eukaryotic cells. Their intracellular effects are often mediated via discrete subcellular signaling microdomains. In this review, we will discuss state-of-the-art techniques to measure cAMP and cGMP in biological samples with a particular focus on live cell imaging approaches, which allow their detection with high temporal and spatial resolution in living cells and tissues. Finally, we will describe how these techniques can be applied to the analysis of second messenger dynamics in subcellular signaling microdomains.

  8. Implementation of ion-beam techniques in microsystems manufacturing: opportunities in cell biology

    Science.gov (United States)

    Campo, E. M.; Lopez-Martinez, M. J.; Fernández, E.; Esteve, J..; Plaza, J. A.

    2009-05-01

    Micromachining techniques are proposed to mass-manufacture innovative silicon oxide micropipettes and conventional boron-silicate pipettes with highly customized tips to address increasingly demanding cell handling procedures. Cell handling has become a crucial procedure in cell biology, especially in nuclear transfer, DNA injection, and in assisted reproductive techniques. Most pipette manufacturing procedures involve tedious artisanal methods prone to failure and with limited functionality. We expect high tip customization to have a large impact in current and future cell manipulation, paving the way for augmented functionality. Although proper biocompatibility assessments remain to be explored, initial pierced embryos are seen to continue their division procedure up to at least 24 hours. The continued cellular division is a good sign of biocompatibility. These results suggest that residual chemical agents or gallium ions injected during milling could be harmless to life development. We conclude that we have produced a novel technique combining microfabrication and Focus Ion Beam processes with great potential for industrial applications.

  9. Characterization of excretory-secretory antigens of adult Toxocara canis by western blotting.

    Science.gov (United States)

    Sudhakar, N R; Samanta, S; Sahu, Shivani; Raina, O K; Gupta, S C; Goswami, T K; Lokesh, K M; Kumar, Ashok

    2014-06-01

    Toxocara canis is one of the most common helminth worm of dogs which continues to stimulate both public health concern alongside the higher scientific interest. It may cause visceral and ocular damage in humans especially in children. The identification of specific antigens of T. canis is important so as to develop better diagnostic techniques. Excretory-secretory (ES) antigens were prepared by culturing the adult T. canis worms in RPMI 1640 medium without serum supplementation followed by ammonium sulphate precipitation. These antigens were separated using sodium dodecyl sulphate-electrophoresis (SDS-PAGE). Recovered proteins ranged from 30 to 384 kDa. The specific reactivity of the T. canis excretory-secretory (TC-ES) proteins was checked by western blotting. The immuno-reactivity of the naturally infected dog sera with the TC-ES antigens showed five bands at 43, 57,105, 139 and 175 kDa. The immuno-reactivity of the hyper immune serum raised in rabbits against TC-ES antigens was observed with ten polypeptides of 21, 25, 30, 37, 45, 50, 57, 69, 77 and 105 kDa. Common antigens band were observed at 57 and 105 KDa. These antigens merit further evaluation as candidate for use in diagnosis of toxocariasis in humans and adult dogs.

  10. Identification of toxocara canis antigens by Western blot in experimentally infected rabbits

    Directory of Open Access Journals (Sweden)

    MORALES Olga Lucía

    2002-01-01

    Full Text Available Toxocariasis is a frequent helminthiasis that can cause visceral and ocular damage in humans specially in children. The identification of specific antigens of Toxocara canis is important in order to develop better diagnostic techniques. Ten rabbits were infected orally with a dose of 5000 Toxocara canis embryonated eggs. Rabbits were bled periodically and an ELISA assay was performed to determine levels of specific Toxocara IgG antibodies. ELISA detected antibodies at day 15 after infection. Western blot (WB assay was performed using excretory/secretory antigens (E/S of T. canis second stage larvae. Different antigen concentrations were evaluated: 150, 200, 250 and 300 µg/mL. The concentration of 250 µg/mL was retained for analysis. Rabbit sera were diluted 1:100. Secondary antibody was used at a dilution of 1:1000. Results of WB indicated that in the first month after infection specific antibodies against the 200 KDa, 116 KDa, 92 KDa and 35 KDa antigens were detected; antibodies against the 92 KDa, 80 KDa, 66 KDa, 45 KDa, 31 KDa and 28 KDa antigens appeared later. All positive sera in the ELISA test were also positive in WB. Two antigen bands, 92 KDa and 35 KDa, were identified since the beginning and throughout the course of infection. These antigens merit further evaluation as candidates for use in diagnosis.

  11. Detection of Rickettsia in Rhipicephalus sanguineus ticks and Ctenocephalides felis fleas from southeastern Tunisia by reverse line blot assay.

    Science.gov (United States)

    Khrouf, Fatma; M'Ghirbi, Youmna; Znazen, Abir; Ben Jemaa, Mounir; Hammami, Adnene; Bouattour, Ali

    2014-01-01

    Ticks (n = 663) and fleas (n = 470) collected from domestic animals from southeastern Tunisia were screened for Rickettsia infection using reverse line blot assay. Evidence of spotted fever group Rickettsia was obtained. We detected Rickettsia felis in fleas, Rickettsia massiliae Bar 29 and the Rickettsia conorii Israeli spotted fever strain in ticks, and Rickettsia conorii subsp. conorii and Rickettsia spp. in both arthropods. The sensitivity of the adopted technique allowed the identification of a new association between fleas and R. conorii subsp. conorii species. The presence of these vector-borne Rickettsia infections should be considered when diagnosing this disease in humans in Tunisia.

  12. Molecular biology techniques for the diagnosis of cutaneous T-cell lymphoma.

    Science.gov (United States)

    Wood, G S; Haeffner, A; Dummer, R; Crooks, C F

    1994-04-01

    The molecular biologic analysis of TCR gene rearrangements by Southern blot analysis and various PCR-based assays has contributed significantly to the understanding of CTCL. It is now known that CTCL is a monoclonal T-cell disorder like other T-cell neoplasms and that the same tumor clone is generally present in all sites of tissue involvement. Relative to histopathologic examination, the enhanced sensitivity of molecular biologic assays has allowed the diagnosis of CTCL at an early stage in many cases. In fact, molecular biologic analysis of TCR gene rearrangements suggests that CTCL may contain a dominant monoclonal tumor cell population from the time of its earliest clinically recognizable lesions, such as the cutaneous patches once termed large plaque parapsoriasis and now generally regarded as early CTCL. Furthermore, available data indicate that, at least in some cases, tumor cells are distributed widely among cutaneous and extracutaneous tissues at a time long before this involvement can be appreciated morphologically. It is apparent that, in addition to their value in the early diagnosis and staging of cutaneous lymphomas, these molecular biologic assays are valuable in monitoring the response to therapy, detecting early relapse, and improving understanding of the compartmentalization and trafficking of tumor cells. In order to reap the full clinical benefit from this new information, however, it is important to perform prospective long-term studies designed to determine the clinical significance of molecular biologic data. In addition, the complexity of cutaneous lymphoproliferative disorders dictates that molecular biologic clonality data should never be interpreted in a vacuum. In skin disease, dominant clonality does not always equate with clinical malignancy. The proper diagnosis of CTCL and other cutaneous lymphoproliferative diseases requires the thoughtful integration of molecular biologic data with the clinicopathologic and immunophenotypic

  13. Study on production of useful metabolites by development of advanced cell culture techniques using radiation

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Byung Yeoup; Lee, Seung Sik; Bai, Hyounwoo; Singh, Sudhir; Lee, Eun Mi; Hong, Sung Hyun; Park, Chul Hong; Srilatha, B.; Kim, Mi Ja; Lee, Ohchul

    2012-01-15

    The purpose of this project is improvement of investigation, materialization and evaluation techniques on effectiveness for functional natural compounds throughout development of tissue/cell culture techniques for mass production of useful metabolites using radiation. Research scope includes Development of a technique for radiation tissue and cell culture, Database construction for radiation response in plants and radiation effects, Construction of general-purpose national based techniques of cell culture technique using radiation. Main results are as follow: Development of a technique for radiation tissue and cell culture for Erigeron breviscapus (Vant.) Hand. Mazz.; Identification and functional analysis of AtTDX (chaperone and peroxidase activities); Functional analysis of radiation(gamma ray, electron beam, and proton beam) induced chaperon protein activities (AtTDX); Determine the action mechanism of yPrx2; Development of transgenic plant with bas I gene from Arabidopsis; Development of transgenic plant with EoP gene from centipedegrass; Identification of radiation induced multi functional compounds from Aloe; Determination of the effects of radiation on removing undesirable color and physiological activities (Schizandra chinensis baillon, centipedegrass); Determine the action mechanism of transgenic plant with 2-Cys Prx for heat stress resistance; Determination of the effects of centipedegrass extracts on anti-cancer activities; Functional analysis of centipedegrass extracts (anti-virus effects)

  14. A Rapid Culture Technique Produces Functional Dendritic-Like Cells from Human Acute Myeloid Leukemia Cell Lines

    Directory of Open Access Journals (Sweden)

    Jian Ning

    2011-01-01

    Full Text Available Most anti-cancer immunotherapeutic strategies involving dendritic cells (DC as vaccines rely upon the adoptive transfer of DC loaded with exogenous tumour-peptides. This study utilized human acute myeloid leukemia (AML cells as progenitors from which functional dendritic-like antigen presenting cells (DLC were generated, that constitutively express tumour antigens for recognition by CD8+ T cells. DLC were generated from AML cell lines KG-1 and MUTZ-3 using rapid culture techniques and appropriate cytokines. DLC were evaluated for their cell-surface phenotype, antigen uptake and ability to stimulate allogeneic responder cell proliferation, and production of IFN-γ; compared with DC derived from normal human PBMC donors. KG-1 and MUTZ-3 DLC increased expression of CD80, CD83, CD86, and HLA-DR, and MUTZ-3 DLC downregulated CD14 and expressed CD1a. Importantly, both KG-1 and MUTZ-3-derived DLC promoted proliferation of allogeneic responder cells more efficiently than unmodified cells; neither cells incorporated FITC-labeled dextran, but both stimulated IFN-γ production from responding allogeneic CD8+ T cells. Control DC produced from PBMC using the FastDC culture also expressed high levels of critical cell surface ligands and demonstrated good APC function. This paper indicates that functional DLC can be cultured from the AML cell lines KG-1 and MUTZ-3, and FastDC culture generates functional KG-1 DLC.

  15. In vitro isolation and cultivation of rabbit tracheal epithelial cells using tissue explant technique.

    Science.gov (United States)

    Shi, Hong-Can; Lu, Dan; Li, Hai-Jia; Han, Shi; Zeng, Yan-Jun

    2013-04-01

    Epithelial cells from tracheal mucosa offer significant potential as a cell source in development of tissue-engineered trachea. The purpose of this study was to investigate and optimize a suitable culture system for tracheal epithelial cells, including the methods of primary culture, passage, identification, and cryopreservation. Epithelial cells were isolated from rabbit tracheal mucosa using tissue explant technique and were subjected to immunohistochemistry, immunofluorescence, and cryopreservation after purification. Epithelial cells reached confluency at 14-15 d. Immunohistochemical staining for cytokeratin showed brown yellow-positive cytoplasm and blue-counterstained nuclei, while immunofluorescence staining for cytokeratin showed green-positive cytoplasm and clear cell outline, indicating that the cultured cells had properties of epithelial cells. After recovery, epithelial cells exhibited high survival and viability. The results demonstrated that in vitro isolation and cultivation model was successfully established to provide high proliferative capacity, typical morphology and characteristics of tracheal epithelial cells from trachea mucosa by the use of the tissue explant technique.

  16. Reliable Wireless Data Acquisition and Control Techniques within Nuclear Hot Cell Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, J.L.; Tulenko, J.

    2000-09-20

    On this NEER project the University of Florida has investigated and applied advanced communications techniques to address data acquisition and control problems within the Fuel Conditioning Facility (FCF) of Argonne National Laboratory-West (ANL-W) in Idaho Falls. The goals of this project have been to investigate and apply wireless communications techniques to solve the problem of communicating with and controlling equipment and systems within a nuclear hot cell facility with its attendant high radiation levels. Different wireless techniques, including radio frequency, infrared and power line communications were reviewed. For each technique, the challenges of radiation-hardened implementation were addressed. In addition, it has been a project goal to achieve the highest level of system reliability to ensure safe nuclear operations. Achievement of these goals would allow the eventual elimination of through-the-wall, hardwired cabling that is currently employed in the hot cell, along wit h all of the attendant problems that limit measurement mobility and flexibility.

  17. [A technique of rhesus monkey neural progenitor cells intravitreal transplant to rats].

    Science.gov (United States)

    Bian, Hui; Fan, Yao-Dong; Guo, Li-Yun; Yu, Hua-Lin

    2012-02-01

    To investigate a simple and effective intraocular xenotransplant technique of rhesus monkey neural progenitor cells to rats, mechanical injury was induced in the rat's right retina. And the GFP-labeled rhesus monkey neural progenitor cells suspension was slowly injected into the vitreous space of the right injured and left control eye. Confocal image suggested that the xenografted cells survived in both the injured and control eye, meanwhile the cells integrated in the injured right retina. The results demonstrated that intravitreal xenotransplant could be adopted as a simple and reliable method.

  18. The value of the Lugol's iodine staining technique for the identification of vaginal epithelial cells.

    Science.gov (United States)

    Hausmann, R; Pregler, C; Schellmann, B

    1994-01-01

    This paper reports on the specificity of the Lugol's iodine staining technique for the detection of vaginal epithelial cells on penile swabs. Air-dried swabs taken from the glans of the penis of 153 hospital patients and from 50 healthy volunteers, whose last sexual intercourse had taken place at least 5 days previously, were stained with Lugol's solution. Glycogenated cells were found in more than 50% of the cases studied, even in healthy volunteers without urethritis. In almost all of these cases the smear contained at least a few polygonal nucleated epithelial cells showing an unequivocal positive Lugol reaction. These cells cannot be distinguished from superficial or intermediate vaginal cells, by cytomorphology or staining. Urinary tract infections had no influence on the glycogen content of male squamous epithelial cells. On the basis of these results the Lugol's method can no longer be assumed to prove the presence of vaginal cells in penile swabs.

  19. Simplification of bovine somatic cell nuclear transfer by application of a zona-free manipulation technique

    DEFF Research Database (Denmark)

    Booth, P J; Tan, S J; Reipurth, R

    2001-01-01

    Contemporary nuclear transfer techniques often require the involvement of skilled personnel and extended periods of micromanipulation. Here, we present details of the development of a nuclear transfer technique for somatic cells that is both simpler and faster than traditional methods.......8% of cultured oocytes). Subsequent application of the optimized technique for nuclear transfer using nine different granulosa cell primary cultures (cultured in 0.5% serum for 5-12 days) generated 37.6 +/- 3.9% (11 replicates; range, 16.4-58.1 blastocysts per successfully fused and surviving reconstructed...... embryo (after activation), and 33.6 +/- 3.7% blastocysts per attempted reconstructed embryo. Mean day 7 total blastocyst cell numbers from 5 clone families was 128.1 +/- 15.3. The ongoing pregnancy rate of recipients each receiving two nuclear transfer blastocysts is 3/13 (23.1 recipients pregnant at 5...

  20. Anesthesia Technique In A Patient With Langerhans Cell Histiocytosis For Diagnostic Biopsy

    Directory of Open Access Journals (Sweden)

    Abdi S

    2005-07-01

    Full Text Available Histiocytosis under general anesthesia. In these patients, depend on organs involvement and dysfunction, anesthesia technique and specific drugs should be selected.of langerhans cells consist of a range of clinical manifestations, including bone eosimophilic granuloma, Hand-Schuller-Chiristian syndrome and Letterer-Siwe disease. Definitive diagnosis is based on biopsy of involved tissues. This report describes anesthesia technique in a 2 years old girl for diagnostic biopsy

  1. Study on Production of Useful Metabolites by Development of Advanced Cell Culture Techniques Using Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Byung Yeoup; Kim, J. H.; Lee, S. S.; Shyamkumar, B.; An, B. C.; Moon, Y. R.; Lee, E. M.; Lee, M. H.

    2009-02-15

    The purpose of this project is improvement of investigation, materialization and evaluation techniques on effectiveness for functional natural compounds throughout development of tissue/cell culture techniques for mass production of useful metabolites using radiation. Research scope includes 1) Development of a technique for radiation tissue and cell culture, 2) Database construction for radiation response in plants and radiation effects, 3) Construction of general-purpose national based techniques of cell culture technique using radiation. Main results are as follow: Establishment of a tissue culture system (Rubus sp., Lithospermum erythrorhizon, and Rhodiola rosea); characterization of radiation activated gene expression from cultivated bokbunja (Rubus sp.) and Synechocystis sp., identification of gamma-ray induced color change in plants; identification of sensitivity to gamma-ray from Omija (Schisandra chinensis) extract; identification of the response of thylakoid proteins to gamma-ray in spinach and Arabidopsis; identification of gamma-ray induced gene relating to pigment metabolism; characterization of different NPQ changes to gamma-irradiated plants; verification of the effects of rare earth element including anti-bacterial and anti-fungal properties and as a growth enhancer; identification of changes in the growth of gamma-irradiated Synechocystis; and investigation of liquid cell culture conditions from Rhodiola rosea

  2. Study on production of useful metabolites by development of advanced cell culture techniques using radiation

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Byung Yeoup; Kim, Jinhong; Lee, Seung Sik; Bai, Hyounwoo; An, Byung Chull; Lee, Eun Mi; Lee, Jae Taek; Kim, Mi Ja

    2010-12-15

    The purpose of this project is improvement of investigation, materialization and evaluation techniques on effectiveness for functional natural compounds throughout development of tissue/cell culture techniques for mass production of useful metabolites using radiation. Research scope includes Development of a technique for radiation tissue and cell culture, Database construction for radiation response in plants and radiation effects, Construction of general-purpose national based techniques of cell culture technique using radiation. Main results are as follow: Isolation and identification of radiation induced basI gene; Determination of stresses sensitivities by transformating basI gene into arabidopsis; Isolation and identification of radiation induced chaperon proteins (PaAhpC and yPrxII) from Pseudomonas and yeast, and structural and functional analysis of the proteins; Determination of oxidative and heat resistance by transformating PaAhpC; Isolation and identification of maysin and its derivatives from centipedgrass; Investigation of enhancement technique for improving maysin and its derivatives production using radiation; Investigation of removing undesirable color in maysin and its derivatives using radiation; Determination of the effect of radiation on physiological functions of centipedgrass extracts; Identification of H{sub 2}O{sub 2} removing enzyme in radiation irradiated plant (Spinach); Determination of the effects of centipedgrass extracts on anti-obesity and anti-cancer activities.

  3. Accuracy of Reverse Dot-Blot PCR in Detection of Different β-Globin Gene Mutations.

    Science.gov (United States)

    El-Fadaly, N; Abd-Elhameed, A; Abd-Elbar, E; El-Shanshory, M

    2016-06-01

    Prevention programs for β-thalassemia based on molecular diagnosis of heterozygous carriers and/or patients require the use of reliable mutation screening methods. The aim of this study was to compare between direct DNA sequencing, and reverse dot-blot PCR in detection of different β-globin gene mutations in Egyptian children with β-thalassemia. Forty children with β-thalassemia were subjected to mutation analysis, performed by both direct DNA sequencing and β-globin Strip Assay MED™ (based on reverse dot-blot PCR). The most frequent mutant alleles detected by reverse dot-blot PCR were; IVSI-110 G>A (31.25 %), IVS I-6 T > C (21.25 %), and IVS I-1 G>A (20 %). Relatively less frequent mutant alleles detected by reverse dot-blot PCR were "IVSII-1 G>A (5 %), IVSII-745 C>G (5 %), IVSII-848 C>A (2.5 %), IVSI-5 G>C (2.5 %), -87 C>G(2.5 %), and cd39 C>T (2.5 %)", While the genotypes of three patients (6 alleles 7.5 %) were not detected by reverse dot-blot PCR. Mutant alleles detected by direct DNA sequencing were the same as reverse dot-blot PCR method except it revealed the genotypes of 3 undetected patients (one patient was homozygous IVSI-110 G>A, and two patients were homozygous IVS I-1 G>A. Sensitivity of the reverse dot-blot PCR was 92.5 % when compared to direct DNA sequencing for detecting β-thalassemia mutations. Our results therefore suggest that, direct DNA sequencing may be preferred over reverse dot-blot PCR in critical diagnostic situations like genetic counseling for prenatal diagnosis.

  4. CRITERIA OF POSITIVITY FOR Ig ANTIBODIES IN THE METHOD OF IMMUNE BLOTTING OF LYME DISEASE

    Directory of Open Access Journals (Sweden)

    V G Barskova

    2001-01-01

    Full Text Available There are currently no accepted criteria for positive Western blots in Russian patients with Lyme borreliosis. The purpose of the current study was to develop criteria for a positive IgG westem-blot to aid particularly in the diagnosis of patients with joint manifestation of the disorder. Patients: 97 with Lyme disease, 145 - control subjects. IgG antibody responses were determined to 3 species ofB.burgdorferi sensu lato by Western blotting, using blots prepared by manufacturer. The best discriminatory ability of test criteria was chained by requiring any 3 of 11 IgG bands, a definition that could be used with B. burgdorferi sensu stricto, B.garinii and B.afzelii strains. With these 3 antigen preparation, positive IgG blots were found in 0 to 18% of patients with localized erythema migrans of < 4 weeks duration, 23 to 39% of those with disseminated infection < 20 weeks duration, and in 39 to 46% of those with late arthritis/arthralgia of >6 months duration the specificity was 93 to 99%. Thus, IgG Western blotting may bring greater specificity to serologic testing in Lyme borreliosis, but the sensitivity is limited.

  5. Analysis of Leakage Reduction Techniques in Independent-Gate DG FinFET SRAM Cell

    Directory of Open Access Journals (Sweden)

    Vandna Sikarwar

    2013-01-01

    Full Text Available Scaling of devices in bulk CMOS technology leads to short-channel effects and increase in leakage. Static random access memory (SRAM is expected to occupy 90% of the area of SoC. Since leakage becomes the major factor in SRAM cell, it is implemented using FinFET. Further, double-gate FinFET devices became a better choice for deep submicron technologies. With this consideration in our research work, 6T SRAM cell is implemented using independent-gate DG FinFET in which both the opposite sides of gates are controlled independently which provides better scalability to the SRAM cell. The device is implemented using different leakage reduction techniques such as gated-Vdd technique and multithreshold voltage technique to reduce leakage. Therefore, power consumption in the SRAM cell is reduced and provides better performance. Independent-gate FinFET SRAM cell using various leakage reduction techniques has been simulated using Cadence virtuoso tool in 45 nm technology.

  6. How to Distinguish Between the Activity of HDAC1-3 and HDAC6 with Western Blot.

    Science.gov (United States)

    Beyer, Mandy; Kiweler, Nicole; Mahboobi, Siavosh; Krämer, Oliver H

    2017-01-01

    Histone deacetylases (HDACs) catalyze the deacetylation of lysine residues in their target proteins. This biochemical modification can have profound effects on the functions of these proteins and a dysregulation of HDAC activity contributes to severe diseases, including neoplastic transformation. In the following chapter, we present a strategy that allows to distinguish between the inhibition of the class I HDACs HDAC1, 2, and 3 and of the class IIb HDAC HDAC6. This method is based on Western blot and relies on the detection of hyperacetylated substrates of class I or class IIb HDACs in lysates from cells that were treated with histone deacetylase inhibitors (HDACi).

  7. Measurement of the cell membrane capacitance and conductance of colonic crypt cells of the rat using the patch clamp technique

    CERN Document Server

    Schill, C

    2005-01-01

    Using the patch clamp technique the membrane capacitance and membrane conductance of colonic crypt cells of the rat was measured. The influence of the intracellular agonists Ca++, cAMP and of osmotic changes on the membrane capacitance and conductance was studied.

  8. Recent Advances in Genetic Technique of Microbial Report Cells and Their Applications in Cell Arrays

    Directory of Open Access Journals (Sweden)

    Do Hyun Kim

    2015-01-01

    Full Text Available Microbial cell arrays have attracted consistent attention for their ability to provide unique global data on target analytes at low cost, their capacity for readily detectable and robust cell growth in diverse environments, their high degree of convenience, and their capacity for multiplexing via incorporation of molecularly tailored reporter cells. To highlight recent progress in the field of microbial cell arrays, this review discusses research on genetic engineering of reporter cells, technologies for patterning live cells on solid surfaces, cellular immobilization in different polymers, and studies on their application in environmental monitoring, disease diagnostics, and other related fields. On the basis of these results, we discuss current challenges and future prospects for novel microbial cell arrays, which show promise for use as potent tools for unraveling complex biological processes.

  9. Sample preparation and in situ hybridization techniques for automated molecular cytogenetic analysis of white blood cells

    Energy Technology Data Exchange (ETDEWEB)

    Rijke, F.M. van de; Vrolijk, H.; Sloos, W. [Leiden Univ. (Netherlands)] [and others

    1996-06-01

    With the advent in situ hybridization techniques for the analysis of chromosome copy number or structure in interphase cells, the diagnostic and prognostic potential of cytogenetics has been augmented considerably. In theory, the strategies for detection of cytogenetically aberrant cells by in situ hybridization are simple and straightforward. In practice, however, they are fallible, because false classification of hybridization spot number or patterns occurs. When a decision has to be made on molecular cytogenetic normalcy or abnormalcy of a cell sample, the problem of false classification becomes particularly prominent if the fraction of aberrant cells is relatively small. In such mosaic situations, often > 200 cells have to be evaluated to reach a statistical sound figure. The manual enumeration of in situ hybridization spots in many cells in many patient samples is tedious. Assistance in the evaluation process by automation of microscope functions and image analysis techniques is, therefore, strongly indicated. Next to research and development of microscope hardware, camera technology, and image analysis, the optimization of the specimen for the (semi)automated microscopic analysis is essential, since factors such as cell density, thickness, and overlap have dramatic influences on the speed and complexity of the analysis process. Here we describe experiments that have led to a protocol for blood cell specimen that results in microscope preparations that are well suited for automated molecular cytogenetic analysis. 13 refs., 4 figs., 1 tab.

  10. Electrostatic endothelial cell seeding technique for small-diameter (<6 mm) vascular prostheses: feasibility testing.

    Science.gov (United States)

    Bowlin, G L; Rittgers, S E

    1997-01-01

    Multiple studies have indicated the importance of surface charge in the adhesion of multiple cardiovascular cell lines including platelets and endothelial cells on the substrate materials (1,4,7-10,12-15). It is the purpose of this article to report a feasibility study conducted using an electrostatic endothelial cell seeding technique. The feasibility study was conducted using human umbilical vein endothelial cells (HUVEC), a static pool apparatus, a voltage source, and a parallel plate capacitor. The HUVEC concentration and seeding times were constant at 560,000 HUVEC/ml and 30 min, respectively. Scanning electron microscopy examination of the endothelial cell adhesion indicated that an induced temporary positive surface charge on e-PTFE graft material enhances the number and the maturation (flattening) of HUVECs adhered. The results indicated that the total number of endothelial cells adhered (70.9 mm2) was increased from 9198 +/- 1194 HUVECs on the control (no induced surface charge) e-PTFE to 22,482 +/- 4814 HUVECs (2.4 x control) on the maximum induced positive surface charge. The total number of cells in the flattened phase of adhesion increased from 837 +/- 275 to 6785 +/- 1012 HUVECs (8.1x) under identical conditions. Thus, the results of the feasibility study support the premise that electrostatic interaction is an important factor in both the endothelial cell adhesion and spreading processes and suggest that the electrostatic seeding technique may lead to an increased patency of small diameter (<6 mm) vascular prostheses.

  11. Microphotographs of cyanobacteria documenting the effects of various cell-lysis techniques

    Science.gov (United States)

    Rosen, Barry H.; Loftin, Keith A.; Smith, Christopher E.; Lane, Rachael F.; Keydel, Susan P.

    2011-01-01

    Cyanotoxins are a group of organic compounds biosynthesized intracellularly by many species of cyanobacteria found in surface water. The United States Environmental Protection Agency has listed cyanotoxins on the Safe Drinking Water Act's Contaminant Candidate List 3 for consideration for future regulation to protect public health. Cyanotoxins also pose a risk to humans and other organisms in a variety of other exposure scenarios. Accurate and precise analytical measurements of cyanotoxins are critical to the evaluation of concentrations in surface water to address the human health and ecosystem effects. A common approach to total cyanotoxin measurement involves cell membrane disruption to release the cyanotoxins to the dissolved phase followed by filtration to remove cellular debris. Several methods have been used historically, however no standard protocols exist to ensure this process is consistent between laboratories before the dissolved phase is measured by an analytical technique for cyanotoxin identification and quantitation. No systematic evaluation has been conducted comparing the multiple laboratory sample processing techniques for physical disruption of cell membrane or cyanotoxins recovery. Surface water samples collected from lakes, reservoirs, and rivers containing mixed assemblages of organisms dominated by cyanobacteria, as well as laboratory cultures of species-specific cyanobacteria, were used as part of this study evaluating multiple laboratory cell-lysis techniques in partnership with the U.S. Environmental Protection Agency. Evaluated extraction techniques included boiling, autoclaving, sonication, chemical treatment, and freeze-thaw. Both treated and untreated samples were evaluated for cell membrane integrity microscopically via light, epifluorescence, and epifluorescence in the presence of a DNA stain. The DNA stain, which does not permeate live cells with intact membrane structures, was used as an indicator for cyanotoxin release into the

  12. Evaluation of the Aspergillus Western blot IgG kit for diagnosis of chronic aspergillosis.

    Science.gov (United States)

    Oliva, A; Flori, P; Hennequin, C; Dubus, J-C; Reynaud-Gaubert, M; Charpin, D; Vergnon, J M; Gay, P; Colly, A; Piarroux, R; Pelloux, H; Ranque, S

    2015-01-01

    Immunoprecipitin detection (IPD) is the current reference confirmatory technique for anti-Aspergillus antibody detection; however, the lack of standardization is a critical drawback of this assay. In this study, we evaluated the performance of the Aspergillus Western blot (Asp-WB) IgG kit (LDBio Diagnostics, Lyon, France), a recently commercialized immunoblot assay for the diagnosis of various clinical presentations of chronic aspergillosis. Three hundred eight serum samples from 158 patients with aspergillosis sensu lato (s.l.) were analyzed. More specifically, 267 serum samples were derived from patients with Aspergillus disease, including 89 cases of chronic pulmonary aspergillosis, 10 of aspergilloma, and 32 of allergic bronchopulmonary aspergillosis, while 41 samples were from patients with Aspergillus colonization, including 15 cystic fibrosis (CF) and 12 non-CF patients. For blood donor controls, the Asp-WB specificity was 94%, while the kit displayed a sensitivity for the aspergillosis s.l. diagnosis of 88.6%, with a diagnostic odds ratio (DOR) of 119 (95% confidence interval [CI], 57 to 251). The DOR values were 185.22 (95% CI,78.79 to 435.45) and 43.74 (95% CI, 15.65 to 122.20) for the diagnosis of Aspergillus disease and Aspergillus colonization, respectively. Among the patients, the sensitivities of the Asp-WB in the diagnosis of Aspergillus colonization were 100% and 41.7% in CF and non-CF patients, respectively. The Asp-WB yielded fewer false-negative results than did IPD. In conclusion, the Asp-WB kit performed well for the diagnosis of various clinical presentations of aspergillosis in nonimmunocompromised patients, with an enhanced standardization and a higher sensitivity than with IPD, which is the current reference method.

  13. Microfluidics meet cell biology: bridging the gap by validation and application of microscale techniques for cell biological assays.

    Science.gov (United States)

    Paguirigan, Amy L; Beebe, David J

    2008-09-01

    Microscale techniques have been applied to biological assays for nearly two decades, but haven't been widely integrated as common tools in biological laboratories. The significant differences between several physical phenomena at the microscale versus the macroscale have been exploited to provide a variety of new types of assays (such as gradient production or spatial cell patterning). However, the use of these devices by biologists seems to be limited by issues regarding biological validation, ease of use, and the limited available readouts for assays done using microtechnology. Critical validation work has been done recently that highlights the current challenges for microfluidic methods and suggest ways in which future devices might be improved to better integrate with biological assays. With more validation and improved designs, microscale techniques hold immense promise as a platform to study aspects of cell biology that are not possible using current macroscale techniques.

  14. Rapid Spectrophotometric Technique for Quantifying Iron in Cells Labeled with Superparamagnetic Iron Oxide Nanoparticles: Potential Translation to the Clinic

    OpenAIRE

    Dadashzadeh, Esmaeel R.; Hobson, Matthew; Bryant, L. Henry; Dean, Dana D.; Joseph A Frank

    2013-01-01

    Labeling cells with superparamagnetic iron oxide (SPIO) nanoparticles provides the ability to track cells by Magnetic Resonance Imaging. Quantifying intracellular iron concentration in SPIO labeled cells would allow for the comparison of agents and techniques used to magnetically label cells. Here we describe a rapid spectrophotometric technique (ST) to quantify iron content of SPIO labeled cells, circumventing the previous requirement of an overnight acid digestion. Following lysis with 10% ...

  15. Study on production of useful metabolites by development of advanced cell culture techniques using radiation

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Byung Yeoup; Kim, Jin Hong; Lee, Seung Sik; Kim, Jae Sung; An, Byung Chull; Moon, Yu Ran; Lee, Eun Mi; Lee, Min Hee; Lee, Jae Tack [KAERI, Daejeon (Korea, Republic of)

    2010-02-15

    The purpose of this project is improvement of investigation, materialization and evaluation techniques on effectiveness for functional natural compounds throughout development of tissue/cell culture techniques for mass production of useful metabolites using radiation. Research scope includes 1) Development of a technique for radiation tissue and cell culture, 2) Database construction for radiation response in plants and radiation effects, 3) Construction of general-purpose national based techniques of cell culture technique using radiation. Main results are as follow: mass culture of the adventitious roots of mountain ginseng (Panax ginseng C. A. Meyer) roots using rare earth elements in bioreactor: characterization of a transcription factor EoP gene from centipedegrass and the transcription regulation of LexA from Synechocystis sp PCC6803 and E. coli: identification of gamma-ray induced hydrogenase synthesis in hox gene transformed E. coli: transformation and the selection of the EoP transgene from Arabidopsis, rice and lettuce: Identification of the maysin and maysin derivatives in centipedegrass: characterization of gamma-ray induced color change in Taxus cuspidata: verification of the expression of antioxidant proteins (POD, APX and CAT) to gamma-ray in Arabidopsis: comparison of the response of the expression level to gamma-ray or H{sub 2}O{sub 2} in Arabidopsis; verification of the responses and effects to gamma-ray from plants (analysis of NPQ and ROS levels): the development method for rapidly enhancing maysin content of centipede grass; establishment of mass culture system for red beet

  16. A high efficiency technique for the generation of transgenic sugar beets from stomatal guard cells

    NARCIS (Netherlands)

    Hall, R.D.; Riksen-Bruinsma, T.; Weyens, G.; Rosquin, I.J.; Denys, R.N.; Evans, I.J.; Lathouwers, J.E.; LefObvre, M.P.; Dunwell, J.M.; Tunen, van A.; Krens, F.A.

    1996-01-01

    An optimized protocol has been developed for the efficient and rapid genetic modification of sugar beet (Beta vulgaris L). A polyethylene glycol- mediated DNA transformation technique could be applied to protoplast populations enriched specifically for a single totipotent cell type derived from stom

  17. Novel endoscopic imaging techniques toward in vivo observation of living cancer cells in the gastrointestinal tract.

    Science.gov (United States)

    Inoue, Haruhiro; Kudo, Shin-ei; Shiokawa, Akira

    2005-07-01

    It is now possible to perform microscopic imaging of living cells from both normal mucosa and malignant tissue in the gastrointestinal tract. Endocytoscopy is a catheter-type contact endoscope that has more than 1000-fold magnifying power and can pass through the working channel of the straight-view endoscope. In esophageal cells, the nucleus, cell body, and even the nucleolus were clearly distinguished with high-resolution images comparable with those of conventional cytology. This novel technology has the potential to provide histologic diagnoses during endoscopic examinations, similar to those obtained currently by conventional histology techniques.

  18. Aloe vera is non-toxic to cells: A microculture tetrazolium technique colorimetric assay study

    Directory of Open Access Journals (Sweden)

    Devi Gopakumar

    2014-01-01

    Full Text Available Introduction: Aloe vera (Av, a succulent of Liliaceae family is now a widely used medicinal plant. Its′ application covers a wide spectrum of human diseases, including oral mucosa, gastric mucosa and skin. Aloe vera preparations in the form of gel, mouth washes and cream are applied topically for many oral diseases. The applications include oral lichen planus, candidiasis, oral submucous fibrosis, geographic tongue, etc. Aims and Objectives: To evaluate the cytotoxicity of Av on human fibroblasts. Materials and Methods: Aloe vera preparation (70% was applied on the fibroblast cell lineage and the cell viability was evaluated by microculture tetrazolium technique (MTT colorimetric assay. Results: The cell viability at different concentrations was measured. The cells have maintained their viability at different concentrations used in the study. Conclusion: Our study shows the cell viability at different sample concentrations of Av. This could open up wide clinical applications of Av for reactive, inflammatory and potentially malignant oral and other mucocutaneous diseases.

  19. Live cell imaging techniques to study T cell trafficking across the blood-brain barrier in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Coisne Caroline

    2013-01-01

    Full Text Available Abstract Background The central nervous system (CNS is an immunologically privileged site to which access for circulating immune cells is tightly controlled by the endothelial blood–brain barrier (BBB located in CNS microvessels. Under physiological conditions immune cell migration across the BBB is low. However, in neuroinflammatory diseases such as multiple sclerosis, many immune cells can cross the BBB and cause neurological symptoms. Extravasation of circulating immune cells is a multi-step process that is regulated by the sequential interaction of different adhesion and signaling molecules on the immune cells and on the endothelium. The specialized barrier characteristics of the BBB, therefore, imply the existence of unique mechanisms for immune cell migration across the BBB. Methods and design An in vitro mouse BBB model maintaining physiological barrier characteristics in a flow chamber and combined with high magnification live cell imaging, has been established. This model enables the molecular mechanisms involved in the multi-step extravasation of T cells across the in vitro BBB, to be defined with high-throughput analyses. Subsequently these mechanisms have been verified in vivo using a limited number of experimental animals and a spinal cord window surgical technique. The window enables live observation of the dynamic interaction between T cells and spinal cord microvessels under physiological and pathological conditions using real time epifluorescence intravital imaging. These in vitro and in vivo live cell imaging methods have shown that the BBB endothelium possesses unique and specialized mechanisms involved in the multi-step T cell migration across this endothelial barrier under physiological flow. The initial T cell interaction with the endothelium is either mediated by T cell capture or by T cell rolling. Arrest follows, and then T cells polarize and especially CD4+ T cells crawl over long distances against the direction of

  20. Immobilization of microbial cell and yeast cell and its application to biomass conversion using radiation techniques

    Science.gov (United States)

    Kaetsu, Isao; Kumakura, Minoru; Fujimura, Takashi; Kasai, Noboru; Tamada, Masao

    The recent results of immobilization of cellulase-producing cells and ethanol-fermentation yeast by radiation were reported. The enzyme of cellulase produced by immobilized cells was used for saccharification of lignocellulosic wastes and immobilized yeast cells were used for fermentation reaction from glucose to ethanol. The wastes such as chaff and bagasse were treated by γ-ray or electron-beam irradiation in the presence of alkali and subsequent mechanical crushing, to form a fine powder less than 50 μm in diameter. On the other hand, Trichoderma reesei as a cellulase-producing microbial cell was immobilized on a fibrous carrier having a specific porous structure and cultured to produce cellulase. The enzymatic saccharification of the pretreated waste was carried out using the produced cellulase. The enhanced fermentation process to produce ethanol from glucose with the immobilized yeast by radiation was also studied. The ethanol productivity of immobilized growing yeast cells thus obtained was thirteen times that of free yeast cells in a 1:1 volume of liquid medium to immobilized yeast cells.

  1. Thermal Analysis of a Fast Charging Technique for a High Power Lithium-Ion Cell

    Directory of Open Access Journals (Sweden)

    Victor Manuel García Fernández

    2016-11-01

    Full Text Available The cell case temperature versus time profiles of a multistage fast charging technique (4C-1C-constant voltage (CV/fast discharge (4C in a 2.3 Ah cylindrical lithium-ion cell are analyzed using a thermal model. Heat generation is dominated by the irreversible component associated with cell overpotential, although evidence of the reversible component is also observed, associated with the heat related to entropy from the electrode reactions. The final charging stages (i.e., 1C-CV significantly reduce heat generation and cell temperature during charge, resulting in a thermally safe charging protocol. Cell heat capacity was determined from cell-specific heats and the cell materials’ thickness. The model adjustment of the experimental data during the 2 min resting period between discharge and charge allowed us to calculate both the time constant of the relaxation process and the cell thermal resistance. The obtained values of these thermal parameters used in the proposed model are almost equal to those found in the literature for the same cell model, which suggests that the proposed model is suitable for its implementation in thermal management systems.

  2. SIMSISH technique does not alter the apparent isotopic composition of bacterial cells.

    Directory of Open Access Journals (Sweden)

    Olivier Chapleur

    Full Text Available In order to identify the function of uncultured microorganisms in their environment, the SIMSISH method, combining in situ hybridization (ISH and nanoscale secondary ion mass spectrometry (nanoSIMS imaging, has been proposed to determine the quantitative uptake of specific labelled substrates by uncultured microbes at the single cell level. This technique requires the hybridization of rRNA targeted halogenated DNA probes on fixed and permeabilized microorganisms. Exogenous atoms are introduced into cells and endogenous atoms removed during the experimental procedures. Consequently differences between the original and the apparent isotopic composition of cells may occur. In the present study, the influence of the experimental procedures of SIMSISH on the isotopic composition of carbon in E. coli cells was evaluated with nanoSIMS and compared to elemental analyser-isotopic ratio mass spectrometer (EA-IRMS measurements. Our results show that fixation and hybridization have a very limited, reproducible and homogeneous influence on the isotopic composition of cells. Thereby, the SIMSISH procedure minimizes the contamination of the sample by exogenous atoms, thus providing a means to detect the phylogenetic identity and to measure precisely the carbon isotopic composition at the single cell level. This technique was successfully applied to a complex sample with double bromine - iodine labelling targeting a large group of bacteria and a specific archaea to evaluate their specific (13C uptake during labelled methanol anaerobic degradation.

  3. Fabrication of uniformly cell-laden porous scaffolds using a gas-in-liquid templating technique.

    Science.gov (United States)

    Takei, Takayuki; Aokawa, Ryuta; Shigemitsu, Takamasa; Kawakami, Koei; Yoshida, Masahiro

    2015-11-01

    Design of porous scaffolds in tissue engineering field was challenging. Uniform immobilization of cells in the scaffolds with high porosity was essential for homogeneous tissue formation. The present study was aimed at fabricating uniformly cell-laden porous scaffolds with porosity >74% using the gas-in-liquid foam templating technique. To this end, we used gelatin, microbial transglutaminase and argon gas as a scaffold material, cross-linker of the protein and porogen of scaffold, respectively. We confirmed that a porosity of >74% could be achieved by increasing the gas volume delivered to a gelatin solution. Pore size in the scaffold could be controlled by stirring speed, stirring time and the pore size of the filter through which the gas passed. The foaming technique enabled us to uniformly immobilize a human hepatoblastoma cell line in scaffold. Engraftment efficiency of the cell line entrapped within the scaffold in nude mice was higher than that of cells in free-form. These results showed that the uniformly cell-laden porous scaffolds were promising for tissue engineering.

  4. Review of the Potential of the Ni/Cu Plating Technique for Crystalline Silicon Solar Cells

    Directory of Open Access Journals (Sweden)

    Atteq ur Rehman

    2014-02-01

    Full Text Available Developing a better method for the metallization of silicon solar cells is integral part of realizing superior efficiency. Currently, contact realization using screen printing is the leading technology in the silicon based photovoltaic industry, as it is simple and fast. However, the problem with metallization of this kind is that it has a lower aspect ratio and higher contact resistance, which limits solar cell efficiency. The mounting cost of silver pastes and decreasing silicon wafer thicknesses encourages silicon solar cell manufacturers to develop fresh metallization techniques involving a lower quantity of silver usage and not relying pressing process of screen printing. In recent times nickel/copper (Ni/Cu based metal plating has emerged as a metallization method that may solve these issues. This paper offers a detailed review and understanding of a Ni/Cu based plating technique for silicon solar cells. The formation of a Ni seed layer by adopting various deposition techniques and a Cu conducting layer using a light induced plating (LIP process are appraised. Unlike screen-printed metallization, a step involving patterning is crucial for opening the masking layer. Consequently, experimental procedures involving patterning methods are also explicated. Lastly, the issues of adhesion, back ground plating, process complexity and reliability for industrial applications are also addressed.

  5. Total protein or high-abundance protein: Which offers the best loading control for Western blotting?

    Science.gov (United States)

    Thacker, Jonathan S; Yeung, Derrick H; Staines, W Richard; Mielke, John G

    2016-03-01

    Western blotting routinely involves a control for variability in the amount of protein across immunoblot lanes. Normalizing a target signal to one found for an abundantly expressed protein is widely regarded as a reliable loading control; however, this approach is being increasingly questioned. As a result, we compared blotting for two high-abundance proteins (actin and glyceraldehyde 3-phosphate dehydrogenase [GAPDH]) and two total protein membrane staining methods (Ponceau and Coomassie Brilliant Blue) to determine the best control for loading variability. We found that Ponceau staining optimally balanced accuracy and precision, and we suggest that this approach be considered as an alternative to normalizing with a high-abundance protein.

  6. Indeterminate HIV-1 Western Blots: Etiology, Natural History, and Psychological Reactions

    Science.gov (United States)

    1992-09-16

    systemic lupus erythematosus, rheumatoid arthritis, juvenile onset diabetes mellitus , Sjogren’s disease, thyroiditis, and Crohn’s disease 4 TABLE 8 45...Cat wound ply 0-no; 1-scratched only; 2-bitten only; 3-both BE.2Bb Owned other pets 0-no;l- dog ; 2-rodent;3-other A/< . 2 # BE.3 SMOKING HISTORY 53 BE...blot. Sera from 26 cases with a pet cat were tested for reactivity on Western blots for feline leukemia virus (FeLV) and for feline immunodeficiency

  7. Finds decorated with garnets from Early Avar contexts in the light of their cell techniques

    OpenAIRE

    Heinrich-Tamáska, Orsolya

    2016-01-01

    The present contribution concerns the Early Avar (late 6th and first half of the 7th century AD) metal objects ornamented with garnets from the perspective of the inlay techniques employed. Such inlays occur exclusively on objects made of precious metals, indicating the high value placed on these stones. Besides standard cloisonné, it has been possible to identify techniques such as soldered band settings of single and multiple cells and open-work cellwork (pseudo cloisonné, champlevé à jour)...

  8. Analysis of retinal cell development in chick embryo by immunohistochemistry and in ovo electroporation techniques

    Directory of Open Access Journals (Sweden)

    Pashkova Anna

    2010-01-01

    Full Text Available Abstract Background Retinal cell development has been extensively investigated; however, the current knowledge of dynamic morphological and molecular changes is not yet complete. Results This study was aimed at revealing the dynamic morphological and molecular changes in retinal cell development during the embryonic stages using a new method of targeted retinal injection, in ovo electroporation, and immunohistochemistry techniques. A plasmid DNA that expresses the green fluorescent protein (GFP as a marker was delivered into the sub-retinal space to transfect the chick retinal stem/progenitor cells at embryonic day 3 (E3 or E4 with the aid of pulses of electric current. The transfected retinal tissues were analyzed at various stages during chick development from near the start of neurogenesis at E4 to near the end of neurogenesis at E18. The expression of GFP allowed for clear visualization of cell morphologies and retinal laminar locations for the indication of retinal cell identity. Immunohistochemistry using cell type-specific markers (e.g., Visinin, Xap-1, Lim1+2, Pkcα, NeuN, Pax6, Brn3a, Vimentin, etc. allowed further confirmation of retinal cell types. The composition of retinal cell types was then determined over time by counting the number of GFP-expressing cells observed with morphological characteristics specific to the various retinal cell types. Conclusion The new method of retinal injection and electroporation at E3 - E4 allows the visualization of all retinal cell types, including the late-born neurons, e.g., bipolar cells at a level of single cells, which has been difficult with a conventional method with injection and electroporation at E1.5. Based on data collected from analyses of cell morphology, laminar locations in the retina, immunohistochemistry, and cell counts of GFP-expressing cells, the time-line and dynamic morphological and molecular changes of retinal cell development were determined. These data provide more

  9. Enhanced Cell-Edge Performance with Transmit Power-Shaping and Multipoint, Multiflow Techniques

    Institute of Scientific and Technical Information of China (English)

    Philip Pietrask; Gregg Charltonl; Rui Yang,; Carl Wang

    2011-01-01

    In this paper, we present a technique called "fuzzy cells" that builds on the multicarrier features of Long Term Evolution-Advanced (LTE-A) and high-speed packet access (HSPA). Multiple carriers are aggregated to create a larger system bandwidth, and these carriers are transmitted at different powers by each sector antenna. This creates a set of cell-edge locations that differ from one frequency to the next. System-level simulations are performed to estimate individual user and average throughput for a hexagonal deployment of 3-sector base stations. For moderately high loads, a fuzzy cell deployment can improve tenth percentile (cell-edge) user throughput by 100% and can improve average throughput by about 30% compared with a reuse 1 scheme. Fuzzy ceils reduce inter-cell interference in the same way as higher-order reuse schemes and allow users to access the full system bandwidth.

  10. Analysis of polyethylene glycol (PEG) fusion in cultured neuroblastoma cells via flow cytometry: Techniques & optimization.

    Science.gov (United States)

    Hoffman, Ashley N; Bamba, Ravinder; Pollins, Alonda C; Thayer, Wesley P

    2017-02-01

    Polyethylene glycol (PEG) has long been used as a membrane fusogen, but recently it has been adopted as a technique for peripheral nerve repair. Vertebrate models using PEG fusion have shown improved outcomes when PEG is applied during repair of severed peripheral nerves. The cellular mechanism of PEG fusion in the peripheral nerve repair model has not previously been assessed via flow cytometry. PEG fusion was assessed in this experiment by dying B35 rat neuroblastoma cells with different color fluorescent labels. The different color cells were combined and PEG was applied in concentrations of 50%, 75% and 100%. The amount of cell fusion was assessed via flow cytometry as the percentage of double positive cells. Results showed increasing fusion and decreasing viability with increasing concentrations of PEG.

  11. Comparison of Cell formation techniques in Cellular manufacturing using three cell formation algorithms

    Directory of Open Access Journals (Sweden)

    Prabhat Kumar Giri

    2016-01-01

    Full Text Available In the present era of globalization and competitive market, cellular manufacturing has become a vital tool for meeting the challenges of improving productivity, which is the way to sustain growth. Getting best results of cellular manufacturing depends on the formation of the machine cells and part families. This paper examines advantages of ART method of cell formation over array based clustering algorithms, namely ROC-2 and DCA. The comparison and evaluation of the cell formation methods has been carried out in the study. The most appropriate approach is selected and used to form the cellular manufacturing system. The comparison and evaluation is done on the basis of performance measure as grouping efficiency and improvements over the existing cellular manufacturing system is presented.

  12. A high efficiency technique for the generation of transgenic sugar beets from stomatal guard cells.

    Science.gov (United States)

    Hall, R D; Riksen-Bruinsma, T; Weyens, G J; Rosquin, I J; Denys, P N; Evans, I J; Lathouwers, J E; Lefèbvre, M P; Dunwell, J M; van Tunen, A; Krens, F A

    1996-09-01

    An optimized protocol has been developed for the efficient and rapid genetic modification of sugar beet (Beta vulgaris L.). A polyethylene glycol-mediated DNA transformation technique could be applied to protoplast populations enriched specifically for a single totipotent cell type derived from stomatal guard cells, to achieve high transformation frequencies. Bialaphos resistance, conferred by the pat gene, produced a highly efficient selection system. The majority of plants were obtained within 8 to 9 weeks and were appropriate for plant breeding purposes. All were resistant to glufosinate-ammonium-based herbicides. Detailed genomic characterization has verified transgene integration, and progeny analysis showed Mendelian inheritance.

  13. Pad printing as a film forming technique for polymer solar cells

    DEFF Research Database (Denmark)

    Krebs, Frederik C

    2009-01-01

    Pad printing as a technique for preparing the active layer in polymer solar cells is presented. The technique employs a silicone rubber stamp to pick up the motif from a gravure plate and transfer it to the substrate. The strengths and limitations of pad printing are discussed and polymer solar...... cells prepared by pad printing are presented. Devices were prepared on indium tin oxide substrates but in principle the entire photovoltaic device comprising front and back electrodes, barrier layers and active layer could be printed with no need for vacuum steps. The device geometry comprises a spin...... coated transparent zinc oxide front electrode, a pad printed active layer based on a bulk heterojunction of the thermocleavable polymer poly(3-(2-methylhexyloxycarbonyl)thiophene-co-thiopene) (P3MHOCT) and zinc oxide nanoparticles, spin coated PEDOT:PSS and finally a manually cast thermally cured silver...

  14. Confirmation of Chlamydophila abortus in infected cell culture using Indirect Immunofluorescence technique

    Directory of Open Access Journals (Sweden)

    Krishnan Nair G

    Full Text Available Chlamydophila abortus (C. abortus is an important abortifacient agent in bovines and ovines. Clinical diagnosis of the disease is often difficult. An early diagnosis can be achieved based on direct demonstration of the organism in clinical material and through the cultural recovery of the organism in embryonated chicken egg. For confirmatory diagnosis antigen detection methods or serological techniques can be adopted. The present study is aimed at the confirmatory diagnosis of C. abortus infection by indirect immunofluorescence technique following the isolation of the organism in cell culture. Specific apple green fluorescing inclusions of C. abortus in McCoy cell lines was detected from 72 h to 96 h post infection employing anti-chlamydial group specific monoclonal antibodies. Thus, a confirmatory diagnosis of the infection was possible with this study. [Vet. World 2011; 4(10.000: 473-474

  15. Ferulic acid enhances IgE binding to peanut allergens in western blots.

    Science.gov (United States)

    Phenolic compounds at high concentrations are known to form insoluble complexes with proteins. We hypothesized that this complex formation could interfere with Western blot and ELISA assays for peanut allergens. To verify this, three simple phenolic compounds (ferulic, caffeic, and chlorogenic acids...

  16. PET-blot analysis contributes to BSE strain recognition in C57Bl/6 mice.

    Science.gov (United States)

    Lezmi, Stéphane; Bencsik, Anna; Baron, Thierry

    2006-10-01

    Identification of the strain of agent responsible for bovine spongiform encephalopathy (BSE) can be made histologically through the analysis of both distribution and intensity of brain vacuolar lesions after BSE transmission to mouse. Another useful way to distinguish the BSE agent from other prion strains is the study of the distribution of the abnormal prion protein (PrP(res)). For that purpose, paraffin-embedded tissue blot (PET-blot) method was applied on brains from C57Bl/6 mice infected with cattle BSE, experimental sheep BSE, or feline spongiform encephalopathy (FSE) from a cheetah. PrP(res) distribution was comparable, whichever of the three BSE agent sources was considered and was distinct from the PrP(res) distribution in C57Bl/6 mice inoculated with a French scrapie isolate or with a mouse-adapted scrapie strain (C506M3). These data confirm a common origin of infectious agent responsible for the British and French cattle BSE. They also indicate that PET-blot method appears as a precise complementary tool in prion strain studies because it offers easy and quick assessment of the PrP(res) mapping. Advantages and limits of the PET-blot method are discussed and compared with other established and validated methods of strain typing.

  17. Investigation of Anti-Relaxation Coatings for Alkali-Metal Vapor Cells Using Surface Science Techniques

    OpenAIRE

    Seltzer, S. J.; Michalak, D. J.; Donaldson, M. H.; Balabas, M. V.; Barber, S. K.; Bernasek, S. L.; Bouchiat, M. -A.; Hexemer, A.; Hibberd, A. M.; Kimball, D. F. Jackson; C. Jaye; Karaulanov, T.; Narducci, F. A.; Rangwala, S. A.; Robinson, H. G.

    2010-01-01

    Many technologies based on cells containing alkali-metal atomic vapor benefit from the use of anti-relaxation surface coatings in order to preserve atomic spin polarization. In particular, paraffin has been used for this purpose for several decades and has been demonstrated to allow an atom to experience up to 10,000 collisions with the walls of its container without depolarizing, but the details of its operation remain poorly understood. We apply modern surface and bulk techniques to the stu...

  18. Investigation of anti-Relaxation coatings for alkali-metal vapor cells using surface science techniques

    OpenAIRE

    Seltzer, S. J.

    2011-01-01

    Many technologies based on cells containing alkali-metal atomic vapor benefit from the use of antirelaxation surface coatings in order to preserve atomic spin polarization. In particular, paraffin has been used for this purpose for several decades and has been demonstrated to allow an atom to experience up to 10?000 collisions with the walls of its container without depolarizing, but the details of its operation remain poorly understood. We apply modern surface and bulk techniques to the stud...

  19. Developments in techniques for the isolation, enrichment, main culture conditions and identification of spermatogonial stem cells

    OpenAIRE

    He, Yanan; Chen, Xiaoli; Zhu, Huabin; Wang, Dong

    2015-01-01

    The in vitro culture system of spermatogonial stem cells (SSCs) provides a basis for studies on spermatogenesis, and also contributes to the development of new methods for the preservation of livestock and animal genetic modification. In vitro culture systems have mainly been established for mouse SSCs, but are lacking for farm animals. We reviewed and analyzed the current progress in SSC techniques such as isolation, purification, cultivation and identification. Based on the published studie...

  20. Current techniques for visualizing RNA in cells [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Lilith V.J.C. Mannack

    2016-04-01

    Full Text Available Labeling RNA is of utmost interest, particularly in living cells, and thus RNA imaging is an emerging field. There are numerous methods relying on different concepts ranging from hybridization-based probes, over RNA-binding proteins to chemo-enzymatic modification of RNA. These methods have different benefits and limitations. This review aims to outline the current state-of-the-art techniques and point out their benefits and limitations.

  1. Monitoring programmed cell death of living plant tissues in microfluidics using electrochemical and optical techniques

    DEFF Research Database (Denmark)

    Mark, Christina; Zor, Kinga; Heiskanen, Arto

    This project focuses on developing and applying a tissue culture system with electrochemical and optical detection techniques for tissue culture of barley aleurone layer to increase understanding of the underlying mechanisms of programmed cell death (PCD) in plants. The major advantage of electro...... an optical double-fluorescent probe-system[4]. Currently, we are working on integrating both detection methods into a tissue culture system for immobilised plant tissues....

  2. Compact, common path quantitative phase microscopic techniques for imaging cell dynamics

    Indian Academy of Sciences (India)

    A Anand; P Vora; S Mahajan; V Trivedi; V Chhaniwal; A Singh; R Leitgeb; B Javidi

    2014-01-01

    Microscopy using visible electromagnetic radiation can be used to investigate living cells in various environments. But bright field microscopy only provides two-dimensional (2D) intensity distribution at a single object plane. One of the ways to retrieve object height/thickness information is to employ quantitative phase microscopic (QPM) techniques. Interferometric QPM techniques are widely used for this. Digital holographic microscopy (DHM) is one of the stateof-the-art methods for quantitative three-dimensional (3D) imaging. Usually it is implemented in two-beam geometry, which is prone to mechanical vibrations. But to study dynamics of objects like red blood cells, one needs temporal stability much better than the fluctuations of the object, which the two-beam geometry fails to deliver. One way to overcome this hurdle is to use selfreferencing techniques, in which a portion of the object beam will act as the reference beam. Here the development of self-referencing QPM techniques is described along with the results.

  3. Application of green chemistry techniques to prepare electrocatalysts for direct methanol fuel cells.

    Science.gov (United States)

    Shimizu, Kenichi; Wang, Joanna S; Wai, Chien M

    2010-03-25

    A series of green techniques for synthesizing carbon nanotube-supported platinum nanoparticles and their high electrocatalytic activity toward methanol fuel cell applications are reported. The techniques utilize either the supercritical fluid carbon dioxide or water as a medium for depositing platinum nanoparticles on surfaces of multiwalled or single-walled carbon nanotubes. The catalytic properties of the carbon nanotubes-supported Pt nanoparticle catalysts prepared by four different techniques are compared for anodic oxidation of methanol and cathodic reduction of oxygen using cyclic voltammetry. One technique using galvanic exchange of Pt(2+) in water with zerovalent iron present on the surfaces of as-grown single-walled carbon nanotubes produces a Pt catalyst that shows an unusually high catalytic activity for reduction of oxygen but a negligible activity for oxidation of methanol. This fuel-selective catalyst may have a unique application as a cathode catalyst in methanol fuel cells to alleviate the problems caused by crossover of methanol through the polymer electrolyte membrane.

  4. Non-invasive diagnostic techniques in the diagnosis of squamous cell carcinoma.

    Science.gov (United States)

    Warszawik-Hendzel, Olga; Olszewska, Małgorzata; Maj, Małgorzata; Rakowska, Adriana; Czuwara, Joanna; Rudnicka, Lidia

    2015-12-31

    Squamous cell carcinoma is the second most common cutaneous malignancy after basal cell carcinoma. Although the gold standard of diagnosis for squamous cell carcinoma is biopsy followed by histopathology evaluation, optical non-invasive diagnostic tools have obtained increased attention. Dermoscopy has become one of the basic diagnostic methods in clinical practice. The most common dermoscopic features of squamous cell carcinoma include clustered vascular pattern, glomerular vessels and hyperkeratosis. Under reflectance confocal microscopy, squamous cell carcinoma shows an atypical honeycomb or disarranged pattern of the spinous-granular layer of the epidermis, round nucleated bright cells in the epidermis and round vessels in the dermis. High frequency ultrasound and optical coherence tomography may be helpful in predominantly in pre-surgical evaluation of tumor size. Emerging non-invasive or minimal invasive techniques with possible application in the diagnosis of squamous cell carcinoma of the skin, lip, oral mucosa, vulva or other tissues include high-definition optical coherence tomography, in vivo multiphoton tomography, direct oral microscopy, electrical impedance spectroscopy, fluorescence spectroscopy, Raman spectroscopy, elastic scattering spectroscopy, differential path-length spectroscopy, nuclear magnetic resonance spectroscopy, and angle-resolved low coherence interferometry.

  5. Investigation of diseases through red blood cells' shape using photoacoustic response technique

    Science.gov (United States)

    Biswas, Deblina; Gorey, Abhijeet; Chen, Goerge C. K.; Sharma, Norman; Vasudevan, Srivathsan

    2015-03-01

    Photoacoustic (PA) imaging is a non-invasive real-time technique, widely applied to many biomedical imaging studies in the recent years. While most of these studies have been focussed on obtaining an image after reconstruction, various features of time domain signal (e.g. amplitude, width, rise and relaxation time) would provide very high sensitivity in detecting morphological changes in cells during a biological study. Different haematological disorders (e.g., sickle cell anaemia, thalassemia) exhibit significant morphological cellular changes. In this context, this study explores the possibility of utilizing the developed photoacoustic response technique to apply onto blood samples. Results of our preliminary study demonstrate that there is a significant change in signal amplitude due to change in concentration of the blood. Thus it shows the sensitivity of the developed photoacoustic technique towards red blood cell count (related to haematological disease like anaemia). Subsequently, morphological changes in RBC (i.e. swollen and shrunk compared to normal RBC) induced by hypotonic and hypertonic solutions respectively were also experimented. The result shows a distinct change in PA signal amplitude. This would serve as a diagnostic signature for many future studies on cellular morphological disorders.

  6. Single cell and single molecule techniques for the analysis of the epigenome

    Science.gov (United States)

    Wallin, Christopher Benjamin

    Epigenetic regulation is a critical biological process for the health and development of a cell. Epigenetic regulation is facilitated by covalent modifications to the underlying DNA and chromatin proteins. A fundamental understanding of these epigenetic modifications and their associated interactions at the molecular scale is necessary to explain phenomena including cellular identity, stem cell plasticity, and neoplastic transformation. It is widely known that abnormal epigenetic profiles have been linked to many diseases, most notably cancer. While the field of epigenetics has progressed rapidly with conventional techniques, significant advances remain to be made with respect to combinatoric analysis of epigenetic marks and single cell epigenetics. Therefore, in this dissertation, I will discuss our development of devices and methodologies to address these pertinent issues. First, we designed a preparatory polydimethylsiloxane (PDMS) microdevice for the extraction, purification, and stretching of human chromosomal DNA and chromatin from small cell populations down to a single cell. The valveless device captures cells by size exclusion within the micropillars, entraps the DNA or chromatin in the micropillars after cell lysis, purifies away the cellular debris, and fluorescently labels the DNA and/or chromatin all within a single reaction chamber. With the device, we achieve nearly 100% extraction efficiency of the DNA. The device is also used for in-channel immunostaining of chromatin followed by downstream single molecule chromatin analysis in nanochannels (SCAN). Second, using multi-color, time-correlated single molecule measurements in nanochannels, simultaneous coincidence detection of 2 epigenetic marks is demonstrated. Coincidence detection of 3 epigenetic marks is also established using a pulsed interleaved excitation scheme. With these two promising results, genome-wide quantification of epigenetic marks was pursued. Unfortunately, quantitative SCAN never

  7. Interferometric and nonlinear-optical spectral-imaging techniques for outer space and live cells

    Science.gov (United States)

    Itoh, Kazuyoshi

    2015-12-01

    Multidimensional signals such as the spectral images allow us to have deeper insights into the natures of objects. In this paper the spectral imaging techniques that are based on optical interferometry and nonlinear optics are presented. The interferometric imaging technique is based on the unified theory of Van Cittert-Zernike and Wiener-Khintchine theorems and allows us to retrieve a spectral image of an object in the far zone from the 3D spatial coherence function. The retrieval principle is explained using a very simple object. The promising applications to space interferometers for astronomy that are currently in progress will also be briefly touched on. An interesting extension of interferometric spectral imaging is a 3D and spectral imaging technique that records 4D information of objects where the 3D and spectral information is retrieved from the cross-spectral density function of optical field. The 3D imaging is realized via the numerical inverse propagation of the cross-spectral density. A few techniques suggested recently are introduced. The nonlinear optical technique that utilizes stimulated Raman scattering (SRS) for spectral imaging of biomedical targets is presented lastly. The strong signals of SRS permit us to get vibrational information of molecules in the live cell or tissue in real time. The vibrational information of unstained or unlabeled molecules is crucial especially for medical applications. The 3D information due to the optical nonlinearity is also the attractive feature of SRS spectral microscopy.

  8. Fuel Cell Manufacturing Diagnostic Techniques: IR Thermography with Reactive Flow through Excitation

    Energy Technology Data Exchange (ETDEWEB)

    Manak, A. J.; Ulsh, M.; Bender, G.

    2012-01-01

    While design and material considerations for PEMFCs have a large impact on cost, it is also necessary to consider a transition to high volume production of fuel cell systems, including MEA components, to enable economies of scale and reduce per unit cost. One of the critical manufacturing tasks is developing and deploying techniques to provide in‐process measurement of fuel cell components for quality control. This effort requires a subsidiary task: The study of the effect of manufacturing defects on performance and durability with the objective to establish validated manufacturing tolerances for fuel cell components. This work focuses on the development of a potential quality control method for gas diffusion electrodes (GDEs). The method consists of infrared (IR) thermography combined with reactive flow through (RFT) excitation. Detection of catalyst loading reduction defects in GDE catalyst layers will be presented.

  9. ESR technique for noninvasive way to quantify cyclodextrins effect on cell membranes

    Energy Technology Data Exchange (ETDEWEB)

    Grammenos, A., E-mail: A.Grammenos@ulg.ac.be [Laboratory of Biomedical Spectroscopy, Department of Physics, B5, University of Liege, Sart-Tilman (Belgium); Mouithys-Mickalad, A. [Center of Oxygen, Research and Development (CORD), Department of Chemistry, B6a, University of Liege, Sart-Tilman (Belgium); Guelluy, P.H.; Lismont, M. [Laboratory of Biomedical Spectroscopy, Department of Physics, B5, University of Liege, Sart-Tilman (Belgium); Piel, G. [Laboratory of Pharmaceutical Technology, Department of Pharmacy, CHU, B36, University of Liege, 1 Av. de l' Hopital (Belgium); Hoebeke, M. [Laboratory of Biomedical Spectroscopy, Department of Physics, B5, University of Liege, Sart-Tilman (Belgium)

    2010-07-30

    Research highlights: {yields} ESR: a new tool for cyclodextrins study on living cells. {yields} Cholesterol and phospholipid extraction by Rameb in a dose- and time-dependent way. {yields} Extracted phospholipids and cholesterol form stable aggregates. {yields} ESR spectra show that lipid rafts are damaged by Rameb. {yields} Quantification of the cholesterol extraction on cell membranes in a noninvasive way. -- Abstract: A new way to study the action of cyclodextrin was developed to quantify the damage caused on cell membrane and lipid bilayer. The Electron Spin Resonance (ESR) spectroscopy was used to study the action of Randomly methylated-beta-cyclodextrin (Rameb) on living cells (HCT-116). The relative anisotropy observed in ESR spectrum of nitroxide spin probe (5-DSA and cholestane) is directly related to the rotational mobility of the probe, which can be further correlated with the microviscosity. The use of ESR probes clearly shows a close correlation between cholesterol contained in cells and cellular membrane microviscosity. This study also demonstrates the Rameb ability to extract cholesterol and phospholipids in time- and dose-dependent ways. In addition, ESR spectra enabled to establish that cholesterol is extracted from lipid rafts to form stable aggregates. The present work supports that ESR is an easy, reproducible and noninvasive technique to study the effect of cyclodextrins on cell membranes.

  10. 3D cell culture: a review of current approaches and techniques.

    Science.gov (United States)

    Haycock, John W

    2011-01-01

    Cell culture in two dimensions has been routinely and diligently undertaken in thousands of laboratories worldwide for the past four decades. However, the culture of cells in two dimensions is arguably primitive and does not reproduce the anatomy or physiology of a tissue for informative or useful study. Creating a third dimension for cell culture is clearly more relevant, but requires a multidisciplinary approach and multidisciplinary expertise. When entering the third dimension, investigators need to consider the design of scaffolds for supporting the organisation of cells or the use of bioreactors for controlling nutrient and waste product exchange. As 3D culture systems become more mature and relevant to human and animal physiology, the ability to design and develop co-cultures becomes possible as does the ability to integrate stem cells. The primary objectives for developing 3D cell culture systems vary widely - and range from engineering tissues for clinical delivery through to the development of models for drug screening. The intention of this review is to provide a general overview of the common approaches and techniques for designing 3D culture models.

  11. Assessment of dye distribution in sensitized solar cells by microprobe techniques

    Energy Technology Data Exchange (ETDEWEB)

    Barreiros, M.A., E-mail: alexandra.barreiros@lneg.pt [Laboratório Nacional de Energia e Geologia, LEN/UES, Estrada do Paço do Lumiar, 22, 1649-038 Lisboa (Portugal); Corregidor, V. [IPFN, Instituto Superior Técnico, Universidade de Lisboa, E.N. 10, 2686-953 Sacavém (Portugal); Alves, L.C. [C2TN, Campus Tecnológico e Nuclear, Instituto Superior Técnico, Universidade de Lisboa, E.N. 10, 2686-953 Sacavém (Portugal); Guimarães, F. [Laboratório Nacional de Energia e Geologia, LGM/UCTM, Rua da Amieira, Apartado 1089, 4466-901 S. Mamede de Infesta (Portugal); Mascarenhas, J.; Torres, E.; Brites, M.J. [Laboratório Nacional de Energia e Geologia, LEN/UES, Estrada do Paço do Lumiar, 22, 1649-038 Lisboa (Portugal)

    2015-04-01

    Dye sensitized solar cells (DSCs) have received considerable attention once this technology offers economic and environmental advantages over conventional photovoltaic (PV) devices. The PV performance of a DSC relies on the characteristics of its photoanode, which typically consists of a nanocrystalline porous TiO{sub 2} film, enabled with a large adsorptive surface area. Dye molecules that capture photons from light during device operation are attached to the film nanoparticles. The effective loading of the dye in the TiO{sub 2} electrode is of paramount relevance for controlling and optimizing solar cell parameters. Relatively few methods are known today for quantitative evaluation of the total dye adsorbed on the film. In this context, microprobe techniques come out as suitable tools to evaluate the dye surface distribution and depth profile in sensitized films. Electron Probe Microanalysis (EPMA) and Ion Beam Analytical (IBA) techniques using a micro-ion beam were used to quantify and to study the distribution of the Ru organometallic dye in TiO{sub 2} films, making use of the different penetration depth and beam sizes of each technique. Different 1D nanostructured TiO{sub 2} films were prepared, morphologically characterized by SEM, sensitized and analyzed by the referred techniques. Dye load evaluation in different TiO{sub 2} films by three different techniques (PIXE, RBS and EPMA/WDS) provided similar results of Ru/Ti mass fraction ratio. Moreover, it was possible to assess dye surface distribution and its depth profile, by means of Ru signal, and to visualize the dye distribution in sample cross-section through X-ray mapping by EPMA/EDS. PIXE maps of Ru and Ti indicated an homogeneous surface distribution. The assessment of Ru depth profile by RBS showed that some films have homogeneous Ru depth distribution while others present different Ru concentration in the top layer (2 μm thickness). These results are consistent with the EPMA/EDS maps obtained.

  12. Assessment of dye distribution in sensitized solar cells by microprobe techniques

    Science.gov (United States)

    Barreiros, M. A.; Corregidor, V.; Alves, L. C.; Guimarães, F.; Mascarenhas, J.; Torres, E.; Brites, M. J.

    2015-04-01

    Dye sensitized solar cells (DSCs) have received considerable attention once this technology offers economic and environmental advantages over conventional photovoltaic (PV) devices. The PV performance of a DSC relies on the characteristics of its photoanode, which typically consists of a nanocrystalline porous TiO2 film, enabled with a large adsorptive surface area. Dye molecules that capture photons from light during device operation are attached to the film nanoparticles. The effective loading of the dye in the TiO2 electrode is of paramount relevance for controlling and optimizing solar cell parameters. Relatively few methods are known today for quantitative evaluation of the total dye adsorbed on the film. In this context, microprobe techniques come out as suitable tools to evaluate the dye surface distribution and depth profile in sensitized films. Electron Probe Microanalysis (EPMA) and Ion Beam Analytical (IBA) techniques using a micro-ion beam were used to quantify and to study the distribution of the Ru organometallic dye in TiO2 films, making use of the different penetration depth and beam sizes of each technique. Different 1D nanostructured TiO2 films were prepared, morphologically characterized by SEM, sensitized and analyzed by the referred techniques. Dye load evaluation in different TiO2 films by three different techniques (PIXE, RBS and EPMA/WDS) provided similar results of Ru/Ti mass fraction ratio. Moreover, it was possible to assess dye surface distribution and its depth profile, by means of Ru signal, and to visualize the dye distribution in sample cross-section through X-ray mapping by EPMA/EDS. PIXE maps of Ru and Ti indicated an homogeneous surface distribution. The assessment of Ru depth profile by RBS showed that some films have homogeneous Ru depth distribution while others present different Ru concentration in the top layer (2 μm thickness). These results are consistent with the EPMA/EDS maps obtained.

  13. Corrosion Inhibition Mechanism of Rare Earth Metal on LC4 Al Alloy with Spilt Cell Technique

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new method of studying the corrosion inhibition mechanism of rare earth metal(REM) on LC4 Al alloy with the spilt cell technique was studied. The principle and experimental method of the spilt cell technique were analyzed. By measuring the change of net-electric current between the two electrodes caused by the change of the amount of oxygen in the solution and the addition of CeCl3, the influence of corrosive performance of CeCl3 on LC4 super-power aluminum alloy in the 0.1 mol*L-1 NaCl solution was investigated. Meanwhile, the conditional changes of pH values, CeCl3 solution, additire and time of performance were also studied. Finally, the features of electrode surface were revealed by using SEM and X-ray energy-dispersive spectrometry (EDS). By combining these with other electric chemical techniques, such as potential-time curve, polarization curve et al.

  14. Developments in techniques for the isolation, enrichment, main culture conditions and identification of spermatogonial stem cells.

    Science.gov (United States)

    He, Yanan; Chen, Xiaoli; Zhu, Huabin; Wang, Dong

    2015-12-01

    The in vitro culture system of spermatogonial stem cells (SSCs) provides a basis for studies on spermatogenesis, and also contributes to the development of new methods for the preservation of livestock and animal genetic modification. In vitro culture systems have mainly been established for mouse SSCs, but are lacking for farm animals. We reviewed and analyzed the current progress in SSC techniques such as isolation, purification, cultivation and identification. Based on the published studies, we concluded that two-step enzyme digestion and magnetic-activated cell sorting are fast becoming the main methods for isolation and enrichment of SSCs. With regard to the culture systems, serum and feeders were earlier thought to play an important role in the self-renewal and proliferation of SSCs, but serum- and feeder-free culture systems as a means of overcoming the limitations of SSC differentiation in long-term SSC culture are being explored. However, there is still a need to establish more efficient and ideal culture systems that can also be used for SSC culture in larger mammals. Although the lack of SSC-specific surface markers has seriously affected the efficiency of purification and identification, the transgenic study is helpful for our identification of SSCs. Therefore, future studies on SSC techniques should focus on improving serum- and feeder-free culture techniques, and discovering and identifying specific surface markers of SSCs, which will provide new ideas for the optimization of SSC culture systems for mice and promote related studies in farm animals.

  15. DISKRIMINASI KELAMIN PADA IKAN TUNA SIRIP KUNING, Yellowfin tuna MENGGUNAKAN ANALISIS DOT BLOT DAN ELISA

    Directory of Open Access Journals (Sweden)

    Gusti Ngurah Permana

    2014-08-01

    Full Text Available Pemahaman tentang penentuan jenis kelamin dalam populasi induk merupakan hal yang sangat penting bagi keberhasilan program pembenihan. Pengukuran reaksi antibodi dan aktivitas hormon testosterone, serta estradiol adalah metode dengan potensi yang secara akurat dapat menentukan jenis kelamin ikan tanpa mematikan ikan. Tujuan penelitian ini adalah untuk mengetahui akurasi metode dot blot dan ELISA dengan 11-ketotestorsterone (11-KT yang tersedia secara komersial EIA-kit untuk membedakan jenis kelamin ikan tuna sirip kuning. Hasil analisis menunjukkan bahwa metode dot blot menghasilkan ekspresi vitelogenin tampak jelas pada individu betina dan efek plasma terlihat transparan, jika dibandingkan dengan individu jantan. Interpretasi dari metode ini memerlukan pengalaman dan keahlian dalam akurasi pembacaan hasil. Aktivitas hormon 11-KT dengan sampel klip sirip dan plasma memberikan hasil yang baik dengan aktivitas hormon terlihat jelas.

  16. Development of a new therapeutic technique to direct stem cells to the infarcted heart using targeted microbubbles: StemBells

    NARCIS (Netherlands)

    L. Woudstra; P.A.J. Krijnen (Paul); S.J.P. Bogaards; E. Meinster; R.W. Emmens; T.J.A. Kokhuis (Tom); I.A.E. Bollen; H. Baltzer; S.M.T. Baart; R. Parbhudayal; K. Helder MScN (Onno); V.W.M. van Hinsbergh (Victor); R.J.P. Musters (René); N. de Jong (Nico); O. Kamp (Otto); H.W.M. Niessen (Hans ); A. van Dijk (Annemieke); L.J.M. Juffermans (Lynda)

    2016-01-01

    textabstractSuccessful stem cell therapy after acute myocardial infarction (AMI) is hindered by lack of engraftment of sufficient stem cells at the site of injury. We designed a novel technique to overcome this problem by assembling stem cell-microbubble complexes, named 'StemBells'.StemBells were a

  17. Localization of human immunodeficiency virus antigens in infected cells by scanning/transmission-immunogold techniques

    Energy Technology Data Exchange (ETDEWEB)

    Herrera, M.I.; Santa Maria, I.; de Andres, R.; Najera, R.

    1988-01-01

    An application of high resolution scanning/transmission electron microscopy (STEM) and gold-labelling techniques for the rapid detection of human immunodeficiency virus (HIV) in infected cells has been developed. Experimental in vitro studies for detecting two HIV structural proteins, gp41 and p17, were performed following an indirect labeling procedure that uses monoclonal anti-p17 and anti-gp41 antibodies as primary antibodies and 40 nm gold-linked goat antimouse IgG as secondary antibodies. The cells were then studied by STEM in the scanning mode. Unambiguous localization of the viral antigens was possible by combining the three-dimensional image provided by the secondary electron image and the atomic number-dependent backscattered electron image for the identification of the gold marker. This technique combines both the morphological information and the rapid procedures of scanning electron microscopy with the precise and sensitive antigen detection provided by the use of STEM and immunological methods. The preliminary results of its application to the study of peripheral blood mononuclear cells from four anti-HIV-seropositive patients showing the presence of specific labeling in all of them suggest that it might prove useful for early detection of HIV infection before seroconversion, as well as for quantitative studies.

  18. Western blot diagnosis of vivax malaria with multiple stage-specific antigens of the parasite

    OpenAIRE

    Son, Eui-Sun; Kim, Tong Soo; Nam, Ho-Woo

    2001-01-01

    Western blot analysis was performed to diagnose vivax malaria using stage-specific recombinant antigens. Genomic DNA from the whole blood of a malaria patient was used as templates to amplify the coding regions for the antigenic domains of circumsporozoite protein (CSP-1), merozoite surface protein (MSP-1), apical merozoite antigen (AMA-1), serine repeat antigen (SERA), and exported antigen (EXP-1) of Plasmodium vivax. Each amplified DNA fragment was inserted into a pGEX-4T plasmid to induce ...

  19. Ratiometric analysis of fura red by flow cytometry: a technique for monitoring intracellular calcium flux in primary cell subsets.

    Directory of Open Access Journals (Sweden)

    Emily R Wendt

    Full Text Available Calcium flux is a rapid and sensitive measure of cell activation whose utility could be enhanced with better techniques for data extraction. We describe a technique to monitor calcium flux by flow cytometry, measuring Fura Red calcium dye by ratiometric analysis. This technique has several advantages: 1 using a single calcium dye provides an additional channel for surface marker characterization, 2 allows robust detection of calcium flux by minority cell populations within a heterogeneous population of primary T cells and monocytes 3 can measure total calcium flux and additionally, the proportion of responding cells, 4 can be applied to studying the effects of drug treatment, simultaneously stimulating and monitoring untreated and drug treated cells. Using chemokine receptor activation as an example, we highlight the utility of this assay, demonstrating that only cells expressing a specific chemokine receptor are activated by cognate chemokine ligand. Furthermore, we describe a technique for simultaneously stimulating and monitoring calcium flux in vehicle and drug treated cells, demonstrating the effects of the Gαi inhibitor, pertussis toxin (PTX, on chemokine stimulated calcium flux. The described real time calcium flux assay provides a robust platform for characterizing cell activation within primary cells, and offers a more accurate technique for studying the effect of drug treatment on receptor activation in a heterogeneous population of primary cells.

  20. TEM Cell Testing of Cable Noise Reduction Techniques from 2 MHz to 200 MHz -- Part 2

    Science.gov (United States)

    Bradley, Arthur T.; Evans, William C.; Reed, Joshua L.; Shimp, Samuel K., III; Fitzpatrick, Fred D.

    2008-01-01

    This paper presents empirical results of cable noise reduction techniques as demonstrated in a TEM cell operating with radiated fields from 2 - 200 MHz. It is the second part of a two-paper series. The first paper discussed cable types and shield connections. In this second paper, the effects of load and source resistances and chassis connections are examined. For each topic, well established theories are compared to data from a real-world physical system. Finally, recommendations for minimizing cable susceptibility (and thus cable emissions) are presented. There are numerous papers and textbooks that present theoretical analyses of cable noise reduction techniques. However, empirical data is often targeted to low frequencies (e.g. 100 MHz). Additionally, a comprehensive study showing the relative effects of various noise reduction techniques is needed. These include the use of dedicated return wires, twisted wiring, cable shielding, shield connections, changing load or source impedances, and implementing load- or source-to-chassis isolation. We have created an experimental setup that emulates a real-world electrical system, while still allowing us to independently vary a host of parameters. The goal of the experiment was to determine the relative effectiveness of various noise reduction techniques when the cable is in the presence of radiated emissions from 2 MHz to 200 MHz.

  1. Modeling and simulation of PEM fuel cell's flow channels using CFD techniques

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Edgar F.; Andrade, Alexandre B.; Robalinho, Eric; Bejarano, Martha L.M.; Linardi, Marcelo [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mails: efcunha@ipen.br; abodart@ipen.br; eric@ipen.br; mmora@ipen.br; mlinardi@ipen.br; Cekinski, Efraim [Instituto de Pesquisas Tecnologicas (IPT-SP), Sao Paulo, SP (Brazil)]. E-mail: cekinski@ipt.br

    2007-07-01

    Fuel cells are one of the most important devices to obtain electrical energy from hydrogen. The Proton Exchange Membrane Fuel Cell (PEMFC) consists of two important parts: the Membrane Electrode Assembly (MEA), where the reactions occur, and the flow field plates. The plates have many functions in a fuel cell: distribute reactant gases (hydrogen and air or oxygen), conduct electrical current, remove heat and water from the electrodes and make the cell robust. The cost of the bipolar plates corresponds up to 45% of the total stack costs. The Computational Fluid Dynamic (CFD) is a very useful tool to simulate hydrogen and oxygen gases flow channels, to reduce the costs of bipolar plates production and to optimize mass transport. Two types of flow channels were studied. The first type was a commercial plate by ELECTROCELL and the other was entirely projected at Programa de Celula a Combustivel (IPEN/CNEN-SP) and the experimental data were compared with modelling results. Optimum values for each set of variables were obtained and the models verification was carried out in order to show the feasibility of this technique to improve fuel cell efficiency. (author)

  2. Assessing Adipogenic Potential of Mesenchymal Stem Cells: A Rapid Three-Dimensional Culture Screening Technique

    Directory of Open Access Journals (Sweden)

    Jean F. Welter

    2013-01-01

    Full Text Available Bone-marrow-derived mesenchymal stem cells (MSCs have the potential to differentiate into a number of phenotypes, including adipocytes. Adipogenic differentiation has traditionally been performed in monolayer culture, and, while the expression of a fat-cell phenotype can be achieved, this culture method is labor and material intensive and results in only small numbers of fragile adherent cells, which are not very useful for further applications. Aggregate culture is a cell-culture technique in which cells are induced to form three-dimensional aggregates; this method has previously been used successfully, among others, to induce and study chondrogenic differentiation of MSCs. We have previously published an adaptation of the chondrogenic aggregate culture method to a 96-well plate format. Based on the success of this method, we have used the same format for the preparation of three-dimensional adipogenic cultures. The MSCs differentiate rapidly, the aggregates can be handled and processed for histologic and biochemical assays with ease, and the format offers significant savings in supplies and labor. As a differentiation assay, this method can distinguish between degrees of senescence and appears suitable for testing medium or drug formulations in a high-volume, high-throughput fashion.

  3. Positive IgG Western Blot for Borrelia burgdorferi in Colombia

    Directory of Open Access Journals (Sweden)

    Palacios Ricardo

    1999-01-01

    Full Text Available In order to evaluate the presence of specific IgG antibodies to Borrelia burgdorferi in patients with clinical manifestations associated with Lyme borreliosis in Cali, Colombia, 20 serum samples from patients with dermatologic signs, one cerebrospinal fluid (CSF sample from a patient with chronic neurologic and arthritic manifestations, and twelve serum samples from individuals without clinical signs associated with Lyme borreliosis were analyzed by IgG Western blot. The results were interpreted following the recommendations of the Centers for Diseases Control and Prevention (CDC for IgG Western blots. Four samples fulfilled the CDC criteria: two serum specimens from patients with morphea (localized scleroderma, the CSF from the patient with neurologic and arthritic manifestations, and one of the controls. Interpretation of positive serology for Lyme disease in non-endemic countries must be cautious. However these results suggest that the putative "Lyme-like" disease may correlate with positivity on Western blots, thus raising the possibility that a spirochete genospecies distinct from B. burgdorferi sensu stricto, or a Borrelia species other than B. burgdorferi sensu lato is the causative agent. Future work will focus on a survey of the local tick and rodent population for evidence of spirochete species that could be incriminated as the etiologic agent.

  4. Banding pattern indicative of echinococcosis in a commercial cysticercosis western blot

    Directory of Open Access Journals (Sweden)

    Tappe D

    2009-09-01

    Full Text Available Abstract Objective A commercial cysticercosis Western blot was evaluated for serological cross-reactivity of sera from patients with alveolar (AE and cystic echinococcosis (CE. Methods A total of 161 sera were examined, including 31 sera from AE-patients, 11 sera from CE-patients, 9 sera from patients with other parasitic diseases and 109 sera from patients with unrelated medical conditions. All AE-and CE-sera were also examined by the echinococcosis Western blot. Results More sera from patients with AE than with CE showed cross-reactivity in the form of ladder-like patterns ("Mikado aspect" and untypical bands at 6-8 kDa (71% and 77.4% versus 27.3% and 45.5%, respectively. In contrast, triplets of bands in the area above 50 kDa and between 24 and 39-42 kDa were more frequent in CE than in AE sera. The fuzzy band at 50-55 kDa typical for cysticercosis was absent in all AE and CE sera. Conclusions Atypical banding patterns in the cysticercosis Western blot should raise the suspicion of a metacestode infection different from Taenia solium, i.e. Echinococcus multilocularis or E. granulosus, especially when the Mikado aspect and an altered 6-8 kDa band is visible in the absence of a fuzzy 50-55 kDa band.

  5. DIFFERENTIATION OF PSEUDOCONDYLOMA OF VULVA AND CONDYLOMA ACUMINATA BY DOT BLOT HYBRIDIZATION AND POLYMERASE CHAIN REACTION

    Institute of Scientific and Technical Information of China (English)

    刘跃华; 王家璧; 司静懿

    1996-01-01

    This study differentiated pseudocondyloma of vulva from condyloma acunainata using dot blot hybridization and polymerase chain reaction (PCR). A total of 27 cases o{ pseudocondyloma of vulva and 65 cases of condyloma acuminata were selected for the sttldy. The genital lesions were examined clinically and were biopsled. Each biopsy v-as subjected to histological examination and HPV DNA analysis by dot blot hybridization and PCR. Dot blot analysis detected HPV DNA in 19(82.6%) out of 23 cases of condyloma acuminata and 2(25%) out of 8 cases pseudocondyloma of vulvae(P<0. 05). PCR detected HPV DNA in 51(92.7%) our of 55 cases of eondyloma acuminata, compared with none in 23 cases of pseudocondylorna(P<0. 001). HPV DNA was present in the majority of condyloma acuminata specimens, HPV 6 and 11 were the predominant types. Peudocondyloma is probably not associated with HPV. PCR was the most sensitive and useful techntque for HPV DNA detection.

  6. An improved cell separation technique for marine subsurface sediments: applications for high-throughput analysis using flow cytometry and cell sorting.

    Science.gov (United States)

    Morono, Yuki; Terada, Takeshi; Kallmeyer, Jens; Inagaki, Fumio

    2013-10-01

    Development of an improved technique for separating microbial cells from marine sediments and standardization of a high-throughput and discriminative cell enumeration method were conducted. We separated microbial cells from various types of marine sediment and then recovered the cells using multilayer density gradients of sodium polytungstate and/or Nycodenz, resulting in a notably higher percent recovery of cells than previous methods. The efficiency of cell extraction generally depends on the sediment depth; using the new technique we developed, more than 80% of the total cells were recovered from shallow sediment samples (down to 100 meters in depth), whereas ~50% of cells were recovered from deep samples (100-365 m in depth). The separated cells could be rapidly enumerated using flow cytometry (FCM). The data were in good agreement with those obtained from manual microscopic direct counts over the range 10(4)-10(8) cells cm(-3). We also demonstrated that sedimentary microbial cells can be efficiently collected using a cell sorter. The combined use of our new cell separation and FCM/cell sorting techniques facilitates high-throughput and precise enumeration of microbial cells in sediments and is amenable to various types of single-cell analyses, thereby enhancing our understanding of microbial life in the largely uncharacterized deep subseafloor biosphere.

  7. Apparatus and Techniques for Time-resolved Synchrotron X-ray Diffraction using Diamond Anvil Cells

    Science.gov (United States)

    Smith, J.; Sinogeikin, S. V.; Lin, C.; Rod, E.; Bai, L.; Shen, G.

    2015-12-01

    Complementary advances in synchrotron sources, x-ray optics, area detectors, and sample environment control have recently made possible many time-resolved experimental techniques for studying materials at extreme pressure and temperature conditions. The High Pressure Collaborative Access Team (HPCAT) at the Advanced Photon Source has made a sustained effort to assemble a powerful collection of high-pressure apparatus for time-resolved research, and considerable time has been invested in developing techniques for collecting high-quality time-resolved x-ray scattering data. Herein we present key aspects of the synchrotron beamline and ancillary equipment, including source considerations, rapid (de)compression apparatus, high frequency imaging detectors, and software suitable for processing large volumes of data. A number of examples are presented, including fast equation of state measurements, compression rate dependent synthesis of metastable states in silicon and germanium, and ultrahigh compression rates using a piezoelectric driven diamond anvil cell.

  8. TEM Cell Testing of Cable Noise Reduction Techniques From 2 MHz to 200 MHz - Part 1

    Science.gov (United States)

    Bradley, Arthur T.; Evans, William C.; Reed, Joshua L.; Shimp, Samuel K.; Fitzpatrick, Fred D.

    2008-01-01

    This paper presents empirical results of cable noise reduction techniques as demonstrated in a TEM cell operating with radiated fields from 2 - 200 MHz. It is the first part of a two-paper series. This first paper discusses cable types and shield connections. In the second paper, the effects of load and source resistances and chassis connections are examined. For each topic, well established theories are compared to data from a real-world physical system. Finally, recommendations for minimizing cable susceptibility (and thus cable emissions) are presented. There are numerous papers and textbooks that present theoretical analyses of cable noise reduction techniques. However, empirical data is often targeted to low frequencies (e.g. 100 MHz). Additionally, a comprehensive study showing the relative effects of various noise reduction techniques is needed. These include the use of dedicated return wires, twisted wiring, cable shielding, shield connections, changing load or source impedances, and implementing load- or source-to-chassis isolation. We have created an experimental setup that emulates a real-world electrical system, while still allowing us to independently vary a host of parameters. The goal of the experiment was to determine the relative effectiveness of various noise reduction techniques when the cable is in the presence of radiated emissions from 2 MHz to 200 MHz. The electronic system (Fig. 1) consisted of two Hammond shielded electrical enclosures, one containing the source resistance, and the other containing the load resistance. The boxes were mounted on a large aluminium plate acting as the chassis. Cables connecting the two boxes measured 81 cm in length and were attached to the boxes using standard D38999 military-style connectors. The test setup is shown in Fig. 2. Electromagnetic fields were created using an HP8657B signal generator, MiniCircuits ZHL-42W-SMA amplifier, and an EMCO 5103 TEM cell. Measurements were taken using an Agilent E4401B

  9. Comparison of Southern blot analysis with isotopic and nonisotopic in situ hybridization for the detection of human papillomavirus sequences in invasive carcinoma of the uterine cervix.

    Science.gov (United States)

    D'Amato, L; Pilotti, S; Rotola, A; Di Luca, D; Cassai, E; Rilke, F

    1992-03-01

    To compare the efficiency of hybridization methods for the detection of HPV genome, 22 cases of invasive squamous cell carcinoma of the uterine cervix were analyzed by Southern blot analysis and in situ hybridization carried out with 35S- and biotin-labeled probes. These cases contained from less than one to as many as 50 copies per cell of HPV 16 and 18 types. To increase the sensitivity of biotinylated probes, a silver enhancement procedure of the peroxidase reaction product was applied. Results showed that in situ hybridization performed with isotopic probes is as sensitive as Southern blot analysis and is more sensitive than that performed with biotin-labeled probe. However, the application of the silver enhancement procedure increases the percentage of HPV-positive cases from 27 to 50%.

  10. A microfluidics-based technique for automated and rapid labeling of cells for flow cytometry

    Science.gov (United States)

    Patibandla, Phani K.; Estrada, Rosendo; Kannan, Manasaa; Sethu, Palaniappan

    2014-03-01

    Flow cytometry is a powerful technique capable of simultaneous multi-parametric analysis of heterogeneous cell populations for research and clinical applications. In recent years, the flow cytometer has been miniaturized and made portable for application in clinical- and resource-limited settings. The sample preparation procedure, i.e. labeling of cells with antibodies conjugated to fluorescent labels, is a time consuming (˜45 min) and labor-intensive procedure. Microfluidics provides enabling technologies to accomplish rapid and automated sample preparation. Using an integrated microfluidic device consisting of a labeling and washing module, we demonstrate a new protocol that can eliminate sample handling and accomplish sample and reagent metering, high-efficiency mixing, labeling and washing in rapid automated fashion. The labeling module consists of a long microfluidic channel with an integrated chaotic mixer. Samples and reagents are precisely metered into this device to accomplish rapid and high-efficiency mixing. The mixed sample and reagents are collected in a holding syringe and held for up to 8 min following which the mixture is introduced into an inertial washing module to obtain ‘analysis-ready’ samples. The washing module consists of a high aspect ratio channel capable of focusing cells to equilibrium positions close to the channel walls. By introducing the cells and labeling reagents in a narrow stream at the center of the channel flanked on both sides by a wash buffer, the elution of cells into the wash buffer away from the free unbound antibodies is accomplished. After initial calibration experiments to determine appropriate ‘holding time’ to allow antibody binding, both modules were used in conjunction to label MOLT-3 cells (T lymphoblast cell line) with three different antibodies simultaneously. Results confirm no significant difference in mean fluorescence intensity values for all three antibodies labels (p < 0.01) between the

  11. Thermal diffusivity measurements in the photoacoustic open-cell configuration using simple signal normalization techniques

    Science.gov (United States)

    Balderas-López, J. A.; Mandelis, A.

    2001-09-01

    A generalized model for the open photoacoustic cell configuration (OPC) technique, involving one-dimensional heat diffusion across two layers, is presented. The analytical results are particularly suitable for applications with dielectric solids, such as polymers and resins. Two effective normalization procedures for simple and reliable measurement of the thermal diffusivity of this kind of materials using an OPC are also presented. The thermal diffusivity of three different materials (a dental resin, an epoxy resin, and a polymer foil) was measured and excellent agreement was obtained with some values reported in the literature. 2001 American Institute of Physics.

  12. An Interference-Aware Distributed Transmission Technique for Dense Small Cell Networks

    DEFF Research Database (Denmark)

    Mahmood, Nurul Huda; Berardinelli, Gilberto; Pedersen, Klaus I.

    2015-01-01

    transmission technique that can efficiently manage the interference in an uncoordinated dense small cell network is investigated in this work. The proposed interference aware scheme only requires instantaneous channel state information at the transmitter end towards the desired receiver. Motivated by penalty...... methods in optimization studies, an interference dependent weighting factor is introduced to control the number of parallel transmission streams. The proposed scheme can outperform a more complex benchmark transmission scheme in terms of the sum network throughput in certain scenarios and with realistic...

  13. Comparison of high order modes damping techniques for 800 MHz single cell superconducting cavities

    CERN Document Server

    Shashkov, Ya V; Zobov, M M

    2014-01-01

    Currently, applications of 800 MHz harmonic cavities in both bunch lengthening and shortening regimes are under consideration and discussion in the framework of the High Luminosity LHC project. In this paper we study electromagnetic characteristics of high order modes (HOM) for a single cell 800 MHz superconducting cavity and arrays of such cavities connected by drifts tubes. Different techniques for the HOM damping such as beam pipe grooves, coaxial-notch loads, fluted beam pipes etc. are investigated and compared. The influence of the sizes and geometry of the drift tubes on the HOM damping is analyzed.

  14. Essential Data and Techniques for Conducting Microbial Fuel Cell and other Types of Bioelectrochemical System Experiments

    KAUST Repository

    Logan, Bruce E.

    2012-04-19

    Microbial fuel cells (MFCs) and other bioelectrochemical systems are new technologies that require expertise in a variety of technical areas, ranging from electrochemistry to biological wastewater treatment. There are certain data and critical information that should be included in every MFC study, such as specific surface area of the electrodes, solution conductivity, and power densities normalized to electrode surface area and volumes. Electrochemical techniques such as linear sweep voltammetry can be used to understand the performance of the MFC, but extremely slow scans are required for these biological systems compared to more traditional fuel cells. In this Minireview, the critical information needed for MFC studies is provided with examples of how results can be better conveyed through a full description of materials, the use of proper controls, and inclusion of a more complete electrochemical analysis. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Application of Live-Cell RNA Imaging Techniques to the Study of Retroviral RNA Trafficking

    Directory of Open Access Journals (Sweden)

    Darrin V. Bann

    2012-06-01

    Full Text Available Retroviruses produce full-length RNA that serves both as a genomic RNA (gRNA, which is encapsidated into virus particles, and as an mRNA, which directs the synthesis of viral structural proteins. However, we are only beginning to understand the cellular and viral factors that influence trafficking of retroviral RNA and the selection of the RNA for encapsidation or translation. Live cell imaging studies of retroviral RNA trafficking have provided important insight into many aspects of the retrovirus life cycle including transcription dynamics, nuclear export of viral RNA, translational regulation, membrane targeting, and condensation of the gRNA during virion assembly. Here, we review cutting-edge techniques to visualize single RNA molecules in live cells and discuss the application of these systems to studying retroviral RNA trafficking.

  16. Instrumental analysis of bacterial cells using vibrational and emission Moessbauer spectroscopic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Kamnev, Alexander A. [Laboratory of Biochemistry of Plant-Bacterial Symbioses, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 410049 Saratov (Russian Federation)]. E-mail: aakamnev@ibppm.sgu.ru; Tugarova, Anna V. [Laboratory of Biochemistry of Plant-Bacterial Symbioses, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 410049 Saratov (Russian Federation); Antonyuk, Lyudmila P. [Laboratory of Biochemistry of Plant-Bacterial Symbioses, Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 410049 Saratov (Russian Federation); Tarantilis, Petros A. [Laboratory of Chemistry, Department of Science, Agricultural University of Athens, 11855 Athens (Greece); Kulikov, Leonid A. [Laboratory of Nuclear Chemistry Techniques, Department of Radiochemistry, Faculty of Chemistry, M.V. Lomonosov Moscow State University, 119992 Moscow (Russian Federation); Perfiliev, Yurii D. [Laboratory of Nuclear Chemistry Techniques, Department of Radiochemistry, Faculty of Chemistry, M.V. Lomonosov Moscow State University, 119992 Moscow (Russian Federation); Polissiou, Moschos G. [Laboratory of Chemistry, Department of Science, Agricultural University of Athens, 11855 Athens (Greece); Gardiner, Philip H.E. [Division of Chemistry, School of Science and Mathematics, Sheffield Hallam University, Sheffield S1 1WB (United Kingdom)

    2006-07-28

    In biosciences and biotechnology, the expanding application of physicochemical approaches using modern instrumental techniques is an efficient strategy to obtain valuable and often unique information at the molecular level. In this work, we applied a combination of vibrational (Fourier transform infrared (FTIR), FT-Raman) spectroscopic techniques, useful in overall structural and compositional analysis of bacterial cells of the rhizobacterium Azospirillum brasilense, with {sup 57}Co emission Moessbauer spectroscopy (EMS) used for sensitive monitoring of metal binding and further transformations in live bacterial cells. The information obtained, together with ICP-MS analyses for metals taken up by the bacteria, is useful in analysing the impact of the environmental conditions (heavy metal stress) on the bacterial metabolism and some differences in the heavy metal stress-induced behaviour of non-endophytic (Sp7) and facultatively endophytic (Sp245) strains. The results show that, while both strains Sp7 and Sp245 take up noticeable and comparable amounts of heavy metals from the medium (0.12 and 0.13 mg Co, 0.48 and 0.44 mg Cu or 4.2 and 2.1 mg Zn per gram of dry biomass, respectively, at a metal concentration of 0.2 mM in the medium), their metabolic responses differ essentially. Whereas for strain Sp7 the FTIR measurements showed significant accumulation of polyhydroxyalkanoates as storage materials involved in stress endurance, strain Sp245 did not show any major changes in cellular composition. Nevertheless, EMS measurements showed rapid binding of cobalt(II) by live bacterial cells (chemically similar to metal binding by dead bacteria) and its further transformation in the live cells within an hour.

  17. Correlation of open cell-attached and excised patch clamp techniques.

    Science.gov (United States)

    Filipovic, D; Hayslett, J P

    1995-11-01

    The excised patch clamp configuration provides a unique technique for some types of single channel analyses, but maintenance of stable, long-lasting preparations may be confounded by rundown and/or rapid loss of seal. Studies were performed on the amiloride-sensitive Na+ channel, located on the apical surface of A6 cells, to determine whether the nystatin-induced open cell-attached patch could serve as an alternative configuration. Compared to excised inside-out patches, stable preparations were achieved more readily with the open cell-attached patch (9% vs. 56% of attempts). In both preparations, the current voltage (I-V) relation was linear, current amplitudes were equal at opposite equivalent clamped voltages, and Erev was zero in symmetrical Na+ solutions, indicating similar Na+ activities on the cytosolic and external surfaces of the patch. Moreover, there was no evidence that nystatin altered channel activity in the patch because slope conductance (3-4pS) and Erev (75 mV), when the bath was perfused with a high K:low Na solution (ENa = 80 mV), were nearly equal in both patch configurations. Our results therefore indicate that the nystatin-induced open cell-attached patch can serve as an alternative approach to the excised inside-out patch when experiments require modulation of univalent ions in the cytosol.

  18. Where in the Cell Are You? Probing HIV-1 Host Interactions through Advanced Imaging Techniques

    Directory of Open Access Journals (Sweden)

    Brennan S. Dirk

    2016-10-01

    Full Text Available Viruses must continuously evolve to hijack the host cell machinery in order to successfully replicate and orchestrate key interactions that support their persistence. The type-1 human immunodeficiency virus (HIV-1 is a prime example of viral persistence within the host, having plagued the human population for decades. In recent years, advances in cellular imaging and molecular biology have aided the elucidation of key steps mediating the HIV-1 lifecycle and viral pathogenesis. Super-resolution imaging techniques such as stimulated emission depletion (STED and photoactivation and localization microscopy (PALM have been instrumental in studying viral assembly and release through both cell–cell transmission and cell–free viral transmission. Moreover, powerful methods such as Forster resonance energy transfer (FRET and bimolecular fluorescence complementation (BiFC have shed light on the protein-protein interactions HIV-1 engages within the host to hijack the cellular machinery. Specific advancements in live cell imaging in combination with the use of multicolor viral particles have become indispensable to unravelling the dynamic nature of these virus-host interactions. In the current review, we outline novel imaging methods that have been used to study the HIV-1 lifecycle and highlight advancements in the cell culture models developed to enhance our understanding of the HIV-1 lifecycle.

  19. Where in the Cell Are You? Probing HIV-1 Host Interactions through Advanced Imaging Techniques

    Science.gov (United States)

    Dirk, Brennan S.; Van Nynatten, Logan R.; Dikeakos, Jimmy D.

    2016-01-01

    Viruses must continuously evolve to hijack the host cell machinery in order to successfully replicate and orchestrate key interactions that support their persistence. The type-1 human immunodeficiency virus (HIV-1) is a prime example of viral persistence within the host, having plagued the human population for decades. In recent years, advances in cellular imaging and molecular biology have aided the elucidation of key steps mediating the HIV-1 lifecycle and viral pathogenesis. Super-resolution imaging techniques such as stimulated emission depletion (STED) and photoactivation and localization microscopy (PALM) have been instrumental in studying viral assembly and release through both cell–cell transmission and cell–free viral transmission. Moreover, powerful methods such as Forster resonance energy transfer (FRET) and bimolecular fluorescence complementation (BiFC) have shed light on the protein-protein interactions HIV-1 engages within the host to hijack the cellular machinery. Specific advancements in live cell imaging in combination with the use of multicolor viral particles have become indispensable to unravelling the dynamic nature of these virus-host interactions. In the current review, we outline novel imaging methods that have been used to study the HIV-1 lifecycle and highlight advancements in the cell culture models developed to enhance our understanding of the HIV-1 lifecycle. PMID:27775563

  20. Developing new optical imaging techniques for single particle and molecule tracking in live cells

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Wei [Iowa State Univ., Ames, IA (United States)

    2010-01-01

    Differential interference contrast (DIC) microscopy is a far-field as well as wide-field optical imaging technique. Since it is non-invasive and requires no sample staining, DIC microscopy is suitable for tracking the motion of target molecules in live cells without interfering their functions. In addition, high numerical aperture objectives and condensers can be used in DIC microscopy. The depth of focus of DIC is shallow, which gives DIC much better optical sectioning ability than those of phase contrast and dark field microscopies. In this work, DIC was utilized to study dynamic biological processes including endocytosis and intracellular transport in live cells. The suitability of DIC microscopy for single particle tracking in live cells was first demonstrated by using DIC to monitor the entire endocytosis process of one mesoporous silica nanoparticle (MSN) into a live mammalian cell. By taking advantage of the optical sectioning ability of DIC, we recorded the depth profile of the MSN during the endocytosis process. The shape change around the nanoparticle due to the formation of a vesicle was also captured. DIC microscopy was further modified that the sample can be illuminated and imaged at two wavelengths simultaneously. By using the new technique, noble metal nanoparticles with different shapes and sizes were selectively imaged. Among all the examined metal nanoparticles, gold nanoparticles in rod shapes were found to be especially useful. Due to their anisotropic optical properties, gold nanorods showed as diffraction-limited spots with disproportionate bright and dark parts that are strongly dependent on their orientation in the 3D space. Gold nanorods were developed as orientation nanoprobes and were successfully used to report the self-rotation of gliding microtubules on kinesin coated substrates. Gold nanorods were further used to study the rotational motions of cargoes during the endocytosis and intracellular transport processes in live mammalian

  1. Sizing of SRAM Cell with Voltage Biasing Techniques for Reliability Enhancement of Memory and PUF Functions

    Directory of Open Access Journals (Sweden)

    Chip-Hong Chang

    2016-08-01

    Full Text Available Static Random Access Memory (SRAM has recently been developed into a physical unclonable function (PUF for generating chip-unique signatures for hardware cryptography. The most compelling issue in designing a good SRAM-based PUF (SPUF is that while maximizing the mismatches between the transistors in the cross-coupled inverters improves the quality of the SPUF, this ironically also gives rise to increased memory read/write failures. For this reason, the memory cells of existing SPUFs cannot be reused as storage elements, which increases the overheads of cryptographic system where long signatures and high-density storage are both required. This paper presents a novel design methodology for dual-mode SRAM cell optimization. The design conflicts are resolved by using word-line voltage modulation, dynamic voltage scaling, negative bit-line and adaptive body bias techniques to compensate for reliability degradation due to transistor downsizing. The augmented circuit-level techniques expand the design space to achieve a good solution to fulfill several otherwise contradicting key design qualities for both modes of operation, as evinced by our statistical analysis and simulation results based on complementary metal–oxide–semiconductor (CMOS 45 nm bulk Predictive Technology Model.

  2. Design and Development of Hybrid Multilevel Inverter employing Dual Reference Modulation Technique for Fuel Cell Applications

    Directory of Open Access Journals (Sweden)

    R. Seyezhai

    2011-10-01

    Full Text Available MultiLevel Inverter (MLI has been recognized as an attractive topology for high voltage DC-AC conversion. This paper focuses on a new dual reference modulation technique for a hybrid multilevel inverter employing Silicon carbide (SiC switches for fuel cell applications. The proposed modulation technique employs two reference waveforms and a single inverted sine wave as the carrier waveform. This technique is compared with the conventional dual carrier waveform in terms of output voltage spectral quality and switching losses. An experimental five-level hybrid inverter test rig has been built using SiC switches to implement the proposed algorithm. Gating signals are generated using PIC microcontroller. The performance of the inverter has been analyzed and compared with the result obtained from theory and simulation. Simulation study of Proportional Integral (PI controller for the inverter employing the proposed modulation strategy has been done in MATLAB/SIMULINK. Keywords: Multilevel inverter, SiC , dual reference modulation, switching losses, PI

  3. Unconventional Specimen Preparation Techniques Using High Resolution Low Voltage Field Emission Scanning Electron Microscopy to Study Cell Motility, Host Cell Invasion, and Internal Cell Structures in Toxoplasma gondii

    Science.gov (United States)

    Schatten, Heide; Ris, Hans

    2002-04-01

    Apicomplexan parasites employ complex and unconventional mechanisms for cell locomotion, host cell invasion, and cell division that are only poorly understood. While immunofluorescence and conventional transmission electron microscopy have been used to answer questions about the localization of some cytoskeletal proteins and cell organelles, many questions remain unanswered, partly because new methods are needed to study the complex interactions of cytoskeletal proteins and organelles that play a role in cell locomotion, host cell invasion, and cell division. The choice of fixation and preparation methods has proven critical for the analysis of cytoskeletal proteins because of the rapid turnover of actin filaments and the dense spatial organization of the cytoskeleton and its association with the complex membrane system. Here we introduce new methods to study structural aspects of cytoskeletal motility, host cell invasion, and cell division of Toxoplasma gondii, a most suitable laboratory model that is representative of apicomplexan parasites. The novel approach in our experiments is the use of high resolution low voltage field emission scanning electron microscopy (LVFESEM) combined with two new specimen preparation techniques. The first method uses LVFESEM after membrane extraction and stabilization of the cytoskeleton. This method allows viewing of actin filaments which had not been possible with any other method available so far. The second approach of imaging the parasite's ultrastructure and interactions with host cells uses semithick sections (200 nm) that are resin de-embedded (Ris and Malecki, 1993) and imaged with LVFESEM. This method allows analysis of structural detail in the parasite before and after host cell invasion and interactions with the membrane of the parasitophorous vacuole as well as parasite cell division.

  4. Appropriate materials and preparation techniques for polycrystalline-thin-film thermophotovoltaic cells

    Science.gov (United States)

    Dhere, Neelkanth G.

    1997-03-01

    techniques have paved the way for obtaining epitaxial Hg1-xCdxTe thin films at substrate temperatures of ~180 °C with the desired crystalline perfection, stoichiometry, and doping without the necessity of further annealing for improving either the crystalline quality or dopant activity. Retaining larger mercury proportions during annealing would require heated enclosures as in isothermal VPE, hot-wall technique, vacuum evaporation, hot-wall MOCVD, or close-space sublimation. Pb1-xCdxTe thin films can be prepared by magnetron sputtering from cooled Pb1-xCdxTe targets on heated substrates. Hot-wall technique is suitable for the deposition of Pb1-xCdxTe thin films. Hg1-xCdxTe and Pb1-xCdxTe TPV cells will benefit from the substantial work on CdTe thin film solar cells. The paper reviews work on thin films of ternary and pseudoternary compounds of interest for TPV conversion and methods of their preparation with a view to choosing the appropriate materials and fabrication techniques for polycrystalline-thin-film TPV cells.

  5. Fluorescent detection of Southern blots and PCR-based genetic typing tests

    Energy Technology Data Exchange (ETDEWEB)

    Mansfield, E.S.; Worley, J.M. [Molecular Dynamics, Inc., Sunnyvale, CA (United States); Zimmerman, P.A. [Laboratory of Parasitic Diseases, Bethesda, MD (United States)] [and others

    1994-09-01

    The Southern blot is used to study gene organization, to identify disease-causing genomic rearrangements, or for typing RFLP markers in forensic, paternity, or prenatal diagnostic testing. Fluorescence offers a much greater dynamic range and a more linear response than film used in radioactive or chemiluminescent detection of RFLPs. We therefore investigated using the Fluorimager{trademark} 575 (Molecular Dynamics, Inc.) for analyzing Southern blots. Using a single-locus probe to D2S44 (YNH24) (Promega Corp.), we detect as little as 100 ng (0.05 attomole) genomic DNA. The alkaline phosphatase-labeled probe is detected using AttoPhos (JBL Scientific), and the developed membrane is scanned with the Fluorimager. Biotinylated hybridization probes can also be developed using a streptavidin-alkaline phosphatase conjugate and AttoPhos. The instrument scan parameters can be adjusted to prevent overexposure and accompanying loss of resolution in images of blots, gels, or 96-well microplates. We have used these other sample formats in PCR-based genetic typing assays. We use FluorKit DQS (Molecular Dynamics) to accurately quantify PCR template DNA (1-500 ng) in 96-well microplates scanned using the same instrument. Mutation detection assays run include heteroduplex gels (5% polyacrylamide, 2.7 M urea), short tandem repeat (STR) markers, amplified fragment length polymorphisms (AmpFLP), competitive priming PCR, and allele-specific oligotyping. These assays are run using either 1- or 2-color labeling. We detect unlabeled PCR products, such as the AmpFLP marker D1S80 (Perkin-Elmer) by post-staining gels for 10 minutes with SYBR Green 1 (Molecular Probes) and scanning the wet gel. The Fluorimager scans a 20 x 25 cm sample within three minutes, allowing rapid optimization of fluorescent protocols and high sample throughput.

  6. Electrostatic extrusion as a dispersion technique for encapsulation of cells and bioactive compounds

    Directory of Open Access Journals (Sweden)

    Kostić Ivana T.

    2012-01-01

    Full Text Available Significant development of cells and bioactive compound encapsulation technologies is taking place due to an exceptional possibility of their application in various scientific disciplines, including biomedicine, pharmacy, cosmetology, food and agricultural sciences, beverage production, industrial waste treatment. Despite the broad application of microencapsulation, the literature reviews on dispersion techniques for microcapsule/microbead production, their advantages, restrictions and drawbacks are scarce. The purpose of this paper is to assess the possibilities of electrostatic extrusion for encapsulation of biological material, including living cells in hydrogel microbeads. The paper presents an overview of the mechanisms of droplet formation and controlling experimental parameters for producing microbeads by means of electrostatic extrusion. Electrostatic droplet formation utilizes a special type of physical process taking advantage of electrostatic effects occurring in flowing conductive liquids after introduction of an electric field.When an electrostatic field is applied to the metal needle and an electric charge is induced in the liquid flowing out of the needle, the size of droplet detaching from the needle tip decreases as a funcion of applied electrostatic field. It has been shown that few parameters affect microbead size: applied voltage, electrode geometry, needle size, polarity arrangement and polymer concentration. The electrostatic droplet formation is one of the most precise methods, which enables one to produce spherical and uniform particles ranging from 100 μm up to 1000 μm. Most of the authors report that the encapsulated compounds (drugs, enzymes and living cells remain unaltered after electrostatic extrusion. This technique seems to be particularly promising in biotechnology, pharmaceutical and cosmetics industries, where a low-temperature process, preserving heat-sensitive material is a prerequisite. Future efforts in

  7. Proteínas inmunodominantes de Brucella Melitensis evaluadas por Western Blot

    Directory of Open Access Journals (Sweden)

    Elizabeth Anaya

    1997-01-01

    Full Text Available Se separaron extractos de proteínas totales de Brucella melitensis en gel 15% SDS-PAGE. Su seroreactividad fue analizada por Western Blot con resultados satisfactorios. Para éste propósito sueros controles negativos (n=03, sueros de pacientes con brucelosis (n=34, cólera (n=12, tifoidea (n=02 y tuberculosis (n=02 fueron usados. Esta prueba inmunodiagnóstica detectó bandas seroreactivas altamente específicas (100% correspondientes a 8,14,18, un complejo de 25-48 y 58kDa. La sensibilidad del test fue del 90% usando los sueros antes mencionados.

  8. Artificial Intelligence Techniques for the Estimation of Direct Methanol Fuel Cell Performance

    Science.gov (United States)

    Hasiloglu, Abdulsamet; Aras, Ömür; Bayramoglu, Mahmut

    2016-04-01

    Artificial neural networks and neuro-fuzzy inference systems are well known artificial intelligence techniques used for black-box modelling of complex systems. In this study, Feed-forward artificial neural networks (ANN) and adaptive neuro-fuzzy inference system (ANFIS) are used for modelling the performance of direct methanol fuel cell (DMFC). Current density (I), fuel cell temperature (T), methanol concentration (C), liquid flow-rate (q) and air flow-rate (Q) are selected as input variables to predict the cell voltage. Polarization curves are obtained for 35 different operating conditions according to a statistically designed experimental plan. In modelling study, various subsets of input variables and various types of membership function are considered. A feed -forward architecture with one hidden layer is used in ANN modelling. The optimum performance is obtained with the input set (I, T, C, q) using twelve hidden neurons and sigmoidal activation function. On the other hand, first order Sugeno inference system is applied in ANFIS modelling and the optimum performance is obtained with the input set (I, T, C, q) using sixteen fuzzy rules and triangular membership function. The test results show that ANN model estimates the polarization curve of DMFC more accurately than ANFIS model.

  9. A sensitive non-radioactive northern blot method to detect small RNAs.

    Science.gov (United States)

    Kim, Sang Woo; Li, Zhihua; Moore, Patrick S; Monaghan, A Paula; Chang, Yuan; Nichols, Mark; John, Bino

    2010-04-01

    The continuing discoveries of potentially active small RNAs at an unprecedented rate using high-throughput sequencing have raised the need for methods that can reliably detect and quantitate the expression levels of small RNAs. Currently, northern blot is the most widely used method for validating small RNAs that are identified by methods such as high-throughput sequencing. We describe a new northern blot-based protocol (LED) for small RNA (approximately 15-40 bases) detection using digoxigenin (DIG)-labeled oligonucleotide probes containing locked nucleic acids (LNA) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide for cross-linking the RNA to the membrane. LED generates clearly visible signals for RNA amounts as low as 0.05 fmol. This method requires as little as a few seconds of membrane exposure to outperform the signal intensity using overnight exposure of isotope-based methods, corresponding to approximately 1000-fold improvement in exposure-time. In contrast to commonly used radioisotope-based methods, which require freshly prepared and hazardous probes, LED probes can be stored for at least 6 months, facilitate faster and more cost-effective experiments, and are more environmentally friendly. A detailed protocol of LED is provided in the Supplementary Data.

  10. [Prediction of Encapsulation Temperatures of Copolymer Films in Photovoltaic Cells Using Hyperspectral Imaging Techniques and Chemometrics].

    Science.gov (United States)

    Lin, Ping; Chen, Yong-ming; Yao, Zhi-lei

    2015-11-01

    A novel method of combination of the chemometrics and the hyperspectral imaging techniques was presented to detect the temperatures of Ethylene-Vinyl Acetate copolymer (EVA) films in photovoltaic cells during the thermal encapsulation process. Four varieties of the EVA films which had been heated at the temperatures of 128, 132, 142 and 148 °C during the photovoltaic cells production process were used for investigation in this paper. These copolymer encapsulation films were firstly scanned by the hyperspectral imaging equipment (Spectral Imaging Ltd. Oulu, Finland). The scanning band range of hyperspectral equipemnt was set between 904.58 and 1700.01 nm. The hyperspectral dataset of copolymer films was randomly divided into two parts for the training and test purpose. Each type of the training set and test set contained 90 and 10 instances, respectively. The obtained hyperspectral images of EVA films were dealt with by using the ENVI (Exelis Visual Information Solutions, USA) software. The size of region of interest (ROI) of each obtained hyperspectral image of EVA film was set as 150 x 150 pixels. The average of reflectance hyper spectra of all the pixels in the ROI was used as the characteristic curve to represent the instance. There kinds of chemometrics methods including partial least squares regression (PLSR), multi-class support vector machine (SVM) and large margin nearest neighbor (LMNN) were used to correlate the characteristic hyper spectra with the encapsulation temperatures of of copolymer films. The plot of weighted regression coefficients illustrated that both bands of short- and long-wave near infrared hyperspectral data contributed to enhancing the prediction accuracy of the forecast model. Because the attained reflectance hyperspectral data of EVA materials displayed the strong nonlinearity, the prediction performance of linear modeling method of PLSR declined and the prediction precision only reached to 95%. The kernel-based forecast models were

  11. Investigation of Anti-Relaxation Coatings for Alkali-Metal Vapor Cells Using Surface Science Techniques

    CERN Document Server

    Seltzer, S J; Donaldson, M H; Balabas, M V; Barber, S K; Bernasek, S L; Bouchiat, M -A; Hexemer, A; Hibberd, A M; Kimball, D F Jackson; Jaye, C; Karaulanov, T; Narducci, F A; Rangwala, S A; Robinson, H G; Voronov, D L; Yashchuk, V V; Pines, A; Budker, D

    2010-01-01

    Many technologies based on cells containing alkali-metal atomic vapor benefit from the use of anti-relaxation surface coatings in order to preserve atomic spin polarization. In particular, paraffin has been used for this purpose for several decades and has been demonstrated to allow an atom to experience up to 10,000 collisions with the walls of its container without depolarizing, but the details of its operation remain poorly understood. We present a survey of modern surface science techniques applied to the study of paraffin coatings, in order to characterize the properties that enable the effective preservation of alkali spin polarization. These methods include Fourier transform infrared spectroscopy, differential scanning calorimetry, atomic force microscopy, near-edge X-ray absorption fine structure spectroscopy, and X-ray photoelectron spectroscopy. Experimental results include the determination that crystallinity of the coating material is unnecessary, and the detection of C=C double bonds present with...

  12. The active layer morphology of organic solar cells probed with grazing incidence scattering techniques.

    Science.gov (United States)

    Müller-Buschbaum, Peter

    2014-12-10

    Grazing incidence X-ray scattering (GIXS) provides unique insights into the morphology of active materials and thin film layers used in organic photovoltaic devices. With grazing incidence wide angle X-ray scattering (GIWAXS) the molecular arrangement of the material is probed. GIWAXS is sensitive to the crystalline parts and allows for the determination of the crystal structure and the orientation of the crystalline regions with respect to the electrodes. With grazing incidence small angle X-ray scattering (GISAXS) the nano-scale structure inside the films is probed. As GISAXS is sensitive to length scales from nanometers to several hundred nanometers, all relevant length scales of organic solar cells are detectable. After an introduction to GISAXS and GIWAXS, selected examples for application of both techniques to active layer materials are reviewed. The particular focus is on conjugated polymers, such as poly(3-hexylthiophene) (P3HT).

  13. Photoelectrode Fabrication of Dye-Sensitized Nanosolar Cells Using Multiple Spray Coating Technique

    Directory of Open Access Journals (Sweden)

    Chien-Chih Chen

    2013-01-01

    Full Text Available This paper presents a spray coating technique for fabricating nanoporous film of photoelectrode in dye-sensitized nanosolar cells (DSSCs. Spray coating can quickly fabricate nanoporous film of the photoelectrode with lower cost, which can further help the DSSCs to be commercialized in the future. This paper analyzed photoelectric conversion efficiency of the DSSCs using spray coated photoelectrode in comparison with the photoelectrode made with the doctor blade method. Spray coating can easily control transmittance of the photoelectrode through the multiple spray coating process. This work mainly used a dispersant with help of ultrasonic oscillation to prepare the required nano-TiO2 solution and then sprayed it on the ITO glasses. In this work, a motor-operated conveyor belt was built to transport the ITO glasses automatically for multiple spray coating and drying alternately. Experiments used transmittance of the photoelectrode as a fabrication parameter to analyze photoelectric conversion efficiency of the DSSCs. The influencing factors of the photoelectrode transmittance during fabrication are the spray flow rate, the spray distance, and the moving speed of the conveyor belt. The results show that DSSC with the photoelectrode transmittance of ca. 68.0 ± 1.5% and coated by the spray coating technique has the best photoelectric conversion efficiency in this work.

  14. Flicking technique for microencapsulation of cells in calcium alginate leading to the microtissue formation.

    Science.gov (United States)

    Wong, Soon Chuan; Soon, Chin Fhong; Leong, Wai Yean; Tee, Kian Sek

    2016-01-01

    Microbeads have wide applications in biomedical engineering field that include drug delivery, encapsulation of biomolecules, tissue padding and tissue regeneration. In this paper, we report a simple, yet efficient, flicking technique to produce microcapsules of calcium alginate at a narrow distribution of size. The system consists of an infusion pump and a customised flicker that taps the syringe needle for dispersing microcapsules of sodium alginate that polymerised in the calcium chloride solution. The flow rate of the syringe pump and the velocity of the flicker were studied to achieve a well controlled and tunable size distribution of microbeads ranging from 200 to 400 μm. At a flow rate of 4 μl/min and flicking rate of 80 rpm, a narrow size distribution of microbeads were produced. Via this technique, HaCaT cells were encapsulated in calcium alginate microbeads that grown into microtissues with a size ranging from 100 to 300 μm after two weeks of culture. These microtissues could be potentially useful for pharmacological application.

  15. [Optimization of the immunoelectrophoresis technic (western blot) for the confirmation of human immunodeficiency virus infection (HIV) in Panama].

    Science.gov (United States)

    Pascale, J M; de Austin, E; de Moreno, N O; Ledezma, C; de Márquez, E; Blanco, R; Quiroz, E; Calzada, J; Vincensini, A R; de Martin, M C

    1995-01-01

    The purpose of this study is to report the results of the authors' investigation to apply the western blot technique (WB UP-LCS) in the diagnosis of human immunodeficiency virus type 1 (HIV-1) infection. To do this, the authors separated the proteins of the HIV-1 virus by electrophoresis, based on their molecular weight, in poliacilamide gel with SDS (SDS-PAGE) during 3 hours at 200 volts. Then they electrotransferred these proteins to nitrocellulose paper during four hours at 200 milliamperes, with the aid of external cooling. The nitrocellulose strips were evaluated considering the incubation time (1 and 16 hours), two conjugates (human anti IgG with Peroxidase and human anti IgG Biotin plus Streptatividine with Peroxidase) and two dilutions of the patients' sera (1/50 and 1/100). Based on their results the Authors conclude that, in the first place, the optimal conditions for the test include a dilution of 1/100 of the patients serum, incubation of the serum for 16 hours and the use of the conjugate of anti human IgG with Biotin and Streptavidine with Peroxidase; secondary, that the immunologic reactivity against proteins p24 and gp 160/120 is the most important diagnostic criterion for the confirmation of infection with HIV-1 and that they obtained a diagnostic correlation of 100% at a cost which was 5 to 7 times less than that of the commercial system.

  16. "Enzyme-Linked Immunotransfer Blot Analysis of Somatic and Excretory- Secretory Antigens of Fasciola hepatica in Diagnosis of Human Fasciolosis"

    Directory of Open Access Journals (Sweden)

    MB Rokni

    2004-07-01

    Full Text Available The liver fluke Fasciola hepatica causes fascioliasis, a liver disease in most part of the world and particularly in north of Iran. Diagnosis of the diseases is anchored in coprological manner but serological methods are preferable due to some obscurities. In this study, sera obtained from human patients infected with Fasciola hepatica were tested by the enzymelinked immunotrotransfer blot (EITB technique with the parasite s somatic and excretory-secretory (ES antigens in order to evaluate the diagnostic potential of the assay. The study included sera from 40 patients infected with F. hepatica, 20 infected with hydatidosis, 6 with toxocariasis, 10 with strongyloidiasis, 10 with amoebiasis, 5 with malaria and 30 normal controls. By this assay, most pf the serum samples from humans with fascioliasis recognized two antigenic polypeptides of 27 and 29 kDa using both antigens. The sensitivity, specificity, positive and negative predictive values for somatic antigen were 91.0%, 96.2%, 95.2% and 92.7% respectively, while these parameters as for ES antigen were 95.2%, 98.0%, 97.5% and 96.2%, correspondingly. Totally, two cases of reactions for the first antigen and one for the latter were verified. The study suggests that the 27 and 29 kDa bands for two antigens in EITB test could be considered for the immunodiagnosis of human fascioliasis.

  17. Raman Spectroscopy of Solid Oxide Fuel Cells: Technique Overview and Application to Carbon Deposition Analysis

    KAUST Repository

    Maher, R. C.

    2013-07-30

    Raman spectroscopy is a powerful characterization tool for improving the understanding of solid oxide fuel cells (SOFCs), capable of providing direct, molecularly specific information regarding the physical and chemical processes occurring within functional SOFCs in real time. In this paper we give a summary of the technique itself and highlight ex situ and in situ studies that are particularly relevant for SOFCs. This is followed by a case study of carbon formation on SOFC Ni-based anodes exposed to carbon monoxide (CO) using both ex situ and in situ Raman spectroscopy combined with computational simulations. In situ measurements clearly show that carbon formation is significantly reduced for polarized SOFCs compared to those held at open circuit potential (OCP). Ex situ Raman mapping of the surfaces showed clear variations in the rate of carbon formation across the surface of polarized anodes. Computational simulations describing the geometry of the cell showed that this is due to variations in gas access. These results demonstrate the ability of Raman spectroscopy in combination with traditional characterization tools, to provide detailed understanding of critical processes occurring within functional SOFCs. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Cytomorphological analysis in oral squamous cell carcinoma lesions and normal controls using rub and rinse technique

    Directory of Open Access Journals (Sweden)

    Shaila Mulki

    2014-01-01

    Full Text Available Context: Early diagnosis of oral cancer requires simple noninvasive screening tools. Aim: To analyze the cytomorphological features of keratinocytes in smears obtained from the oral mucosa of oral squamous cell carcinoma (OSCC lesions and normal controls using oral rub and rinse technique. Settings and Design: Oral smears were prepared using oral rub and rinse method in subjects with OSCC cases (n = 35 and apparently healthy normal controls (n = 35. They were subjected to cytomorphometric analysis. Materials and Methods : The smears prepared with the rinse method were stained with Papanicolaou stain. Quantitative assessment of nuclear diameter (ND, cytoplasmic diameter (CD, cellular area (CA, nuclear area (NA, and nuclear cytoplasmic ratio (N:C was carried out. Statistical Analysis Used: Unpaired Student′s t-test was used to compare the mean value between the groups. Results: There was a significant difference between ND, CD, CA, NA, and N: C of oral cancer cells and that of the normal controls. There was increase in the mean ND, NA, and N: C; and decrease in CA and CD of cancer subjects when compared to that of normal controls. Conclusion: Cytomorphometric analysis of keratinocytes obtained with oral rinse method can serve as a useful adjunct in the early diagnosis of OSCCs.

  19. Cell kinetic studies in the epidermis of mouse. III. The percent labelled mitosis (PLM) technique.

    Science.gov (United States)

    Potten, C S; Wichmann, H E; Dobek, K; Birch, J; Codd, T M; Horrocks, L; Pedrick, M; Tickle, S P

    1985-01-01

    Full PLM curves have been obtained for four sites in the mouse. The first peaks have been analysed by computer and the duration of the G2 + M and S phases determined together with their standard deviations. The full curves showed a general similarity for all four sites with no clear second peak. The data are compared with the published data for mouse and human epidermis using the in vivo PLM technique. The timing and shape of the first peak can vary considerably even for one site in mice. Hence, both G2 + M and S can vary in their durations. Cells labelled at one time of day exhibit different kinetic properties to those labelled at another time of day. The duration of G2 + M is shortest in dorsum labelled at 03.00 hours (3 X 2 hr) and longest in tail (up to 7 X 5 hr). The S-phase is shortest in dorsum (6 X 3-7 X 2 hr) and longest in tail or ear (13 X 3-14 X 1 hr). There is also a very large standard deviation in tail and foot. There is little general variability when the psoriatic human data are considered, which is surprising. The general variability amongst the data from experimental mice might also be expected amongst humans which might make comparisons between the cell kinetics of normal and diseased skin difficult.

  20. Fabrication of CdS/CdTe-Based Thin Film Solar Cells Using an Electrochemical Technique

    Directory of Open Access Journals (Sweden)

    I. M. Dharmadasa

    2014-06-01

    Full Text Available Thin film solar cells based on cadmium telluride (CdTe are complex devices which have great potential for achieving high conversion efficiencies. Lack of understanding in materials issues and device physics slows down the rapid progress of these devices. This paper combines relevant results from the literature with new results from a research programme based on electro-plated CdS and CdTe. A wide range of analytical techniques was used to investigate the materials and device structures. It has been experimentally found that n-, i- and p-type CdTe can be grown easily by electroplating. These material layers consist of nano- and micro-rod type or columnar type grains, growing normal to the substrate. Stoichiometric materials exhibit the highest crystallinity and resistivity, and layers grown closer to these conditions show n → p or p → n conversion upon heat treatment. The general trend of CdCl2 treatment is to gradually change the CdTe material’s n-type electrical property towards i-type or p-type conduction. This work also identifies a rapid structural transition of CdTe layer at 385 ± 5 °C and a slow structural transition at higher temperatures when annealed or grown at high temperature. The second transition occurs after 430 °C and requires more work to understand this gradual transition. This work also identifies the existence of two different solar cell configurations for CdS/CdTe which creates a complex situation. Finally, the paper presents the way forward with next generation CdTe-based solar cells utilising low-cost materials in their columnar nature in graded bandgap structures. These devices could absorb UV, visible and IR radiation from the solar spectrum and combine impact ionisation and impurity photovoltaic (PV effect as well as making use of IR photons from the surroundings when fully optimised.

  1. Western Blot Detection of Human Anti-Chikungunya Virus Antibody with Recombinant Envelope 2 Protein

    Science.gov (United States)

    Yang, Zhaoshou; Lee, Jihoo; Ahn, Hye-Jin; Chong, Chom-Kyu; Dias, Ronaldo F.; Nam, Ho-Woo

    2016-01-01

    Chikungunya virus (CHIKV), a tropical pathogen, has re-emerged and has massive outbreaks abruptly all over the world. Containing many dominant epitopes, the envelope E2 protein of CHIKV has been explored for the vaccination or diagnosis. In the present study, the antigenicity of a recombinant expressed intrinsically disorder domain (IUD) of E2 was tested for the detection of the antibody against CHIKV through western blot method. The gene of the IUD of E2 was inserted into 2 different vectors and expressed as recombinant GST-E2 and recombinant MBP-E2 fusion protein, respectively. Two kinds of fusion proteins were tested with 30 CHIKV patient sera and 30 normal sera, respectively. Both proteins were detected by 25 patients sera (83.3%) and 1 normal serum (3.3%). This test showed a relatively high sensitivity and very high specificity of the recombinant E2 proteins to be used as diagnostic antigens against CHIKV infection. PMID:27180586

  2. Analysis of sperm membrane antigens relevant to antisperm antibody using Western blot

    Institute of Scientific and Technical Information of China (English)

    WangHF

    2002-01-01

    Objective:To identify the sperm membrane antigens associated with antisperm antibody.Methods:The antisperm antibody in serum was tested by ELISA.Antisperm antibody positive sera from 18 infertile men and 15 infertile women were used.The molecular weight(MW) of sperm membrane antigens associated with the antisperm antibody was analyzed with antisperm antibody positive serum using Western blot.Results:Eight kinds of MW of sperm membrane antigens were identified.The ratio of identification on the 78 KD(60.7%),60KD(71.4%),51KD(14.9%) and 23KD(14.29%)sperm antigen was higher than other.Conclusion:sperm membrane antigens with MW of 78KD,60KD,51KD and 23KD were associated with antisperm antibody and immunological infertility.

  3. Electrospun nitrocellulose and nylon: Design and fabrication of novel high performance platforms for protein blotting applications

    Directory of Open Access Journals (Sweden)

    Bowlin Gary L

    2007-10-01

    Full Text Available Abstract Background Electrospinning is a non-mechanical processing strategy that can be used to process a variety of native and synthetic polymers into highly porous materials composed of nano-scale to micron-scale diameter fibers. By nature, electrospun materials exhibit an extensive surface area and highly interconnected pore spaces. In this study we adopted a biological engineering approach to ask how the specific unique advantages of the electrospinning process might be exploited to produce a new class of research/diagnostic tools. Methods The electrospinning properties of nitrocellulose, charged nylon and blends of these materials are characterized. Results Nitrocellulose electrospun from a starting concentration of Conclusion The flexibility afforded by electrospinning process makes it possible to tailor blotting membranes to specific applications. Electrospinning has a variety of potential applications in the clinical diagnostic field of use.

  4. Evaluation of the Western blotting method for the diagnosis of congenital toxoplasmosis,

    Directory of Open Access Journals (Sweden)

    Jaqueline Dario Capobiango

    Full Text Available Abstract Objective: To evaluate the Western blotting method for the detection of IgG anti-Toxoplasma gondii (T. gondii (IgG-WB in the serum of children with suspected congenital toxoplasmosis. Methods: We accompanied 47 mothers with acquired toxoplasmosis in pregnancy and their children, between June of 2011 and June of 2014. The IgG-WB was done in house and the test was considered positive if the child had antibodies that recognized at least one band on IgG blots different from the mother's or with greater intensity than the corresponding maternal band, during the first three months of life. Results: 15 children (15.1% met the criteria for congenital toxoplasmosis and 32 (32.3% had the diagnosis excluded. The symptoms were observed in 12 (80.0% children and the most frequent were cerebral calcification in 9 (60.0%, chorioretinitis in 8 (53.3%, and hydrocephalus in 4 (26.6%. IgM antibodies anti-T. gondii detected by chemiluminescence (CL were found in 6 (40.0% children and the polymerase chain reaction (PCR for detection of T. gondii DNA was positive in 5 of 7 performed (71.4%. The sensitivity of IgG-WB was of 60.0% [95% confidence interval (CI 32.3-83.7%] and specificity 43.7% (95% CI 26.7-62.3%. The sensitivity of IgG-WB increased to 76.0 and 89.1% when associated to the research of IgM anti-T. gondii or PCR, respectively. Conclusions: The IgG-WB showed greater sensitivity than the detection of IgM anti-T. gondii; therefore, it can be used for the diagnosis of congenital toxoplasmosis in association with other congenital infection markers.

  5. Imaging techniques to evaluate cell therapy in peripheral artery disease: state of the art and clinical trials.

    Science.gov (United States)

    Grimaldi, Vincenzo; Schiano, Concetta; Casamassimi, Amelia; Zullo, Alberto; Soricelli, Andrea; Mancini, Francesco Paolo; Napoli, Claudio

    2016-05-01

    Cell-based therapies, as potential approach to cure peripheral artery disease (PAD), have been clinically investigated after promising results in preclinical models. The so far published studies are very heterogeneous, as different cell sources, cell types, amounts of administered cells and delivering strategies have been used. Overall, cell therapies for PAD bring about a general improvement of patient's clinical condition, even though conclusions cannot be established due to the small size and non-randomized design of these trials. In this context, non-invasive imaging techniques, aimed to monitor angiogenesis and neovascularization after cell therapy, will help the follow-up of clinical studies. However, still much work is needed to establish advanced imaging procedure to overcome the limitation of the current techniques and to accumulate more data in large populations of patients. Here, we report the main imaging techniques employed to evaluate the outcome of the different cell-based therapies in PAD. Moreover, we focus on both published and ongoing clinical trials utilizing cell therapy in PAD.

  6. Prediction of neural differentiation fate of rat mesenchymal stem cells by quantitative morphological analyses using image processing techniques.

    Science.gov (United States)

    Kazemimoghadam, Mahdieh; Janmaleki, Mohsen; Fouani, Mohamad Hassan; Abbasi, Sara

    2015-02-01

    Differentiation of bone marrow mesenchymal stem cells (BMSCs) into neural cells has received significant attention in recent years. However, there is still no practical method to evaluate differentiation process non-invasively and practically. The cellular quality evaluation method is still limited to conventional techniques, which are based on extracting genes or proteins from the cells. These techniques are invasive, costly, time consuming, and should be performed by relevant experts in equipped laboratories. Moreover, they cannot anticipate the future status of cells. Recently, cell morphology has been introduced as a feasible way of monitoring cell behavior because of its relationship with cell proliferation, functions and differentiation. In this study, rat BMSCs were induced to differentiate into neurons. Subsequently, phase contrast images of cells taken at certain intervals were subjected to a series of image processing steps and cell morphology features were calculated. In order to validate the viability of applying image-based approaches for estimating the quality of differentiation process, neural-specific markers were measured experimentally throughout the induction. The strong correlation between quantitative imaging metrics and experimental outcomes revealed the capability of the proposed approach as an auxiliary method of assessing cell behavior during differentiation.

  7. Light and electron microscopic localization of GABAA-receptors on cultured cerebellar granule cells and astrocytes using immunohistochemical techniques

    DEFF Research Database (Denmark)

    Hansen, Gert Helge; Hösli, E; Belhage, B;

    1991-01-01

    . At the light microscope level specific staining of GABAA-receptors was localized in various types of neurones in explant cultures of rat cerebellum using the indirect peroxidase-antiperoxidase (PAP) technique, whereas no specific staining was found in astrocytes. At the electron microscope level labeling...... of GABAA-receptors was observed in the plasma membrane of both the cell bodies and processes in dissociated primary cultures of cerebellar granule cells using an indirect preembedding immunogold staining technique which in contrast to the classical PAP technique allows quantitative estimations...... to be performed. Quantification of the labeling intensity revealed a higher concentration of GABAA-receptors per microns plasma membrane in the cell bodies than in the processes. In discrete areas an extremely high density of the GABAA-receptors was observed. No specific labeling of GABAA-receptors was observed...

  8. Research Update: Large-area deposition, coating, printing, and processing techniques for the upscaling of perovskite solar cell technology

    Science.gov (United States)

    Razza, Stefano; Castro-Hermosa, Sergio; Di Carlo, Aldo; Brown, Thomas M.

    2016-09-01

    To bring perovskite solar cells to the industrial world, performance must be maintained at the photovoltaic module scale. Here we present large-area manufacturing and processing options applicable to large-area cells and modules. Printing and coating techniques, such as blade coating, slot-die coating, spray coating, screen printing, inkjet printing, and gravure printing (as alternatives to spin coating), as well as vacuum or vapor based deposition and laser patterning techniques are being developed for an effective scale-up of the technology. The latter also enables the manufacture of solar modules on flexible substrates, an option beneficial for many applications and for roll-to-roll production.

  9. Using machine vision and data mining techniques to identify cell properties via microfluidic flow analysis

    Science.gov (United States)

    Horowitz, Geoffrey; Bowie, Samuel; Liu, Anna; Stone, Nicholas; Sulchek, Todd; Alexeev, Alexander

    2016-11-01

    In order to quickly identify the wide range of mechanistic properties that are seen in cell populations, a coupled machine vision and data mining analysis is developed to examine high speed videos of cells flowing through a microfluidic device. The microfluidic device contains a microchannel decorated with a periodical array of diagonal ridges. The ridges compress flowing cells that results in complex cell trajectory and induces cell cross-channel drift, both depend on the cell intrinsic mechanical properties that can be used to characterize specific cell lines. Thus, the cell trajectory analysis can yield a parameter set that can serve as a unique identifier of a cell's membership to a specific cell population. By using the correlations between the cell populations and measured cell trajectories in the ridged microchannel, mechanical properties of individual cells and their specific populations can be identified via only information captured using video analysis. Financial support provided by National Science Foundation (NSF) Grant No. CMMI 1538161.

  10. Test Technique Development on the Irradiated Reconstituted PCVN Specimen in Hot Cell

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Sangbok; Oh, Wanho; Choo, Yongsun; Kim, Minchul; Lee, Bongsang [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2006-07-01

    The degradation of fracture toughness is the important factor to restrict the life of nuclear pressure vessel in PWR reactors. A pressure vessel is operated in conformity with the fracture analysis based on ASME codes to ensure safety margins from the unstable fracture. A fracture analysis is performed based on the result from the Charpy impact tests in PWR reactor, but it has the questions to be exact solutions because the test results give indirect and excessively conservative values. Therefore the research to find an exact toughness parameter is undergoing to use the pre-cracked Charpy v-notch (PCVN). As results the master curve method is proposed in ASTM E1921 to be supposed an appropriate tool to evaluate the fracture toughness for the irradiated, or the operated pressure vessel materials. The surveillance test program to evaluate toughness degradation on existing commercial PWR reactor is performed through the impact test on Charpy specimens. It gives the lack of the specimen to evaluate the safety in toughness for on-going operation beyond design life. To overcome the shortage of specimen, the test method to use a reconstituted PCVN specimen fabricated from the broken half of Charpy specimen is proposed and adopted in foreign reactors. In this paper techniques developed for the reconstituted specimen from the domestic commercial PWR reactor in hot cell are described.

  11. Influence of CdS deposition technique for CdS/CdTe solar cells applications

    Science.gov (United States)

    Rubio, Sandra; Plaza, José Luis; Diéguez, Ernesto

    2014-09-01

    The manufacturing of an optimal window layer is essential for a high efficiency solar cell. CdS thin films were deposited on FTO commercial substrates by two different techniques: Chemical Bath Deposition (CBD), and Closed Space Sublimation (CSS) using SiC rods as electrical heating elements. The composition, morphology, and crystalline structure of the CdS thin films were analyzed by Energy Dispersive X-ray spectroscopy (EDX), Scanning Electron Microscope (SEM), and X-Ray Diffraction (XRD). CdS layers obtained by CSS have shown good stoichiometries of 51.07(Cd at %), and 48.93(S at %), with the presence of disordered microrods of hexagonal shape. The CdS films obtained by CBD exhibited certain contamination from the bath chemical components and a poor defined structure. In conclusion, the layers deposited by electric heating based CSS present a better morphology and crystal structure than the layers deposited by CBD. The CdTe absorber layer deposited by CSS electric heating also shows good cubic structure and morphology.

  12. Investigation of anti-Relaxation coatings for alkali-metal vapor cells using surface science techniques

    Energy Technology Data Exchange (ETDEWEB)

    Seltzer, S. J.; Michalak, D. J.; Donaldson, M. H.; Balabas, M. V.; Barber, S. K.; Bernasek, S. L.; Bouchiat, M.-A.; Hexemer, A.; Hibberd, A. M.; Jackson Kimball, D. F.; Jaye, C.; Karaulanov, T.; Narducci, F. A.; Rangwala, S. A.; Robinson, H. G.; Shmakov, A. K.; Voronov, D. L.; Yashchuk, V. V.; Pines, A.; Budker, D.

    2010-10-11

    Many technologies based on cells containing alkali-metal atomic vapor benefit from the use of antirelaxation surface coatings in order to preserve atomic spin polarization. In particular, paraffin has been used for this purpose for several decades and has been demonstrated to allow an atom to experience up to 10?000 collisions with the walls of its container without depolarizing, but the details of its operation remain poorly understood. We apply modern surface and bulk techniques to the study of paraffin coatings in order to characterize the properties that enable the effective preservation of alkali spin polarization. These methods include Fourier transform infrared spectroscopy, differential scanning calorimetry, atomic force microscopy, near-edge x-ray absorption fine structure spectroscopy, and x-ray photoelectron spectroscopy. We also compare the light-induced atomic desorption yields of several different paraffin materials. Experimental results include the determination that crystallinity of the coating material is unnecessary, and the detection of C=C double bonds present within a particular class of effective paraffin coatings. Further study should lead to the development of more robust paraffin antirelaxation coatings, as well as the design and synthesis of new classes of coating materials.

  13. Study of a viral-dual infection in rainbow trout (Oncorhynchus mykiss) by seroneutralization, western blot and polymerase chain reaction assays.

    Science.gov (United States)

    Rodríguez, S; Vilas, M P; Alonso, M; Pérez, S I

    1995-12-01

    Viral-dual infections in fish are of interest to aquaculture practices but they are rarely described and studied. Several methods were applied in this work to demonstrate a case of coinfection in a reared rainbow trout (Oncorhynchus mykiss) population. Inoculation in cell cultures and cross-neutralization tests were the standard procedures that made it possible to isolate and identify a birnavirus, the infectious pancreatic necrosis virus (IPNV), and suspect of a second virus. Western blotting with both polyclonal and monoclonal antibodies, and reverse transcriptional-polymerase chain reaction (RT-PCR) demonstrate coexistence of both, IPNV and a rhabdovirus.

  14. Rapid detection of intestinal pathogens in fecal samples by an improved reverse dot blot method

    Institute of Scientific and Technical Information of China (English)

    Jian-Ming Xing; Su Zhang; Ying Du; Dan Bi; Li-Hui Yao

    2009-01-01

    AIM:To develop a new, rapid and accurate reverse dot blot (RDB) method for the detection of intestinal pathogens in fecal samples.METHODS:The 12 intestinal pathogens tested were Salmonella spp., Brucella spp., Escherichia coli O157:H7,Clostridium botulinum, Bacillus cereus,Clostridium perfringens, Vibrio parahaemolyticus,Shigella spp., Yersinia enterocolitica, Vibrio cholerae,Listeria monocytogenes and Staphylococcus aureus.The two universal primers were designed to amplify two variable regions of bacterial 16S and 23S rDNA genes from all of the 12 bacterial species tested. Five hundred and forty fecal samples from the diarrhea patients were detected using the improved RDB assay.RESULTS:The methods could identify the 12 intestinal pathogens specifically, and the detection limit was as low as 103 CFUs. The consistent detection rate of the improved RDB assay compared with the traditional culture method was up to 88.75%.CONCLUSION:The hybridization results indicated that the improved RDB assay developed was a reliable method for the detection of intestinal pathogen in fecal samples.

  15. Serological diagnosis of North American Paragonimiasis by Western blot using Paragonimus kellicotti adult worm antigen.

    Science.gov (United States)

    Fischer, Peter U; Curtis, Kurt C; Folk, Scott M; Wilkins, Patricia P; Marcos, Luis A; Weil, Gary J

    2013-06-01

    Abstract. We studied the value of an IgG Western blot (WB) with Paragonimus kellicotti (Pk) antigen for diagnosis of North American paragonimiasis. The test was evaluated with sera from patients with Pk and Paragonimus westermani infections, with control sera from patients with other helminth infections, and sera from healthy Americans. All 11 proven Pk infection sera and two samples from suspected cases that were negative by P. westermani WB at the Centers for Disease Control and Prevention (CDC) contained antibodies to antigens at 34 kDa and at 21/23 kDa. Seven of 7 P. westermani sera contained antibodies to the 34 kDa antigen, but only 2 recognized the 21/23 kDa doublet. No control samples were reactive with these antigens. Antibody reactivity declined after praziquantel treatment. Thus, the P. kellicotti WB appears to be superior to P. westermani WB for diagnosing Pk infections, and it may be useful for assessing responses to treatment.

  16. Binding of 16S rRNA to chloroplast 30S ribosomal proteins blotted on nitrocellulose.

    Science.gov (United States)

    Rozier, C; Mache, R

    1984-10-11

    Protein-RNA associations were studied by a method using proteins blotted on a nitrocellulose sheet. This method was assayed with Escherichia Coli 30S ribosomal components. In stringent conditions (300 mM NaCl or 20 degrees C) only 9 E. coli ribosomal proteins strongly bound to the 16S rRNA: S4, S5, S7, S9, S12, S13, S14, S19, S20. 8 of these proteins have been previously found to bind independently to the 16S rRNA. The same method was applied to determine protein-RNA interactions in spinach chloroplast 30S ribosomal subunits. A set of only 7 proteins was bound to chloroplast rRNA in stringent conditions: chloroplast S6, S10, S11, S14, S15, S17 and S22. They also bound to E. coli 16S rRNA. This set includes 4 chloroplast-synthesized proteins: S6, S11, S15 and S22. The core particles obtained after treatment by LiCl of chloroplast 30S ribosomal subunit contained 3 proteins (S6, S10 and S14) which are included in the set of 7 binding proteins. This set of proteins probably play a part in the early steps of the assembly of the chloroplast 30S ribosomal subunit.

  17. Renaturation of blotted allergens increases the sensitivity of specific IgE detection.

    Science.gov (United States)

    Muro, M D; Fernández, C; Moneo, I

    1996-01-01

    Several authors have demonstrated that renaturation is an essential step for the appropriate recognition of blotted proteins. The use of nonionic detergents has been described as a useful alternative to enhance the antigenicity in immunoblotting, although elution from proteins by detergents has been observed. To measure the influence of different factors on the sensitivity of specific IgE by immunoblotting, we used twenty human sera from atopic patients who were allergic or nonallergic to a common, reliable allergen (grass pollen mixture). The use of Nonidet-P40 was found to be a useful alternative for the renaturation of the allergens. No elution from the membrane was found when employing this detergent, even at high concentrations (3%), and its use gave better sensitivity than methanol. On the other hand, we detected that methanol possessed renaturing properties. A transfer method using diffusion instead of electric transfer gave the best results and two membranes could be obtained from each gel. Using this method, we found that after NP-40 incubation of the membrane, the use of bovine albumin could be omitted as blocking agent and that its use had even deleterious effects.

  18. Rapid Detection of Rifampin-resistant Clinical Isolates of Mycobacterium tuberculosis by Reverse Dot Blot Hybridization

    Institute of Scientific and Technical Information of China (English)

    GUO Qian; WAN Kang Lin; YU Yan; ZHU Yan Ling; ZHAO Xiu Qin; LIU Zhi Guang; ZHANG Yuan Yuan; LI Gui Lian; WEI Jian Hao; WU Yi Mou

    2015-01-01

    Objective A PCR-reverse dot blot hybridization (RDBH) assay was developed for rapid detection of rpoB gene mutations in‘hot mutation region’ of Mycobacterium tuberculosis (M. tuberculosis). Methods 12 oligonucleotide probes based on the wild-type and mutant genotype rpoB sequences of M. tuberculosis were designed to screen the most frequent wild-type and mutant genotypes for diagnosing RIF resistance. 300 M. tuberculosis clinical isolates were detected by RDBH, conventional drug-susceptibility testing (DST) and DNA sequencing to evaluate the RDBH assay. Results The sensitivity and specificity of the RDBH assay were 91.2%(165/181) and 98.3%(117/119), respectively, as compared to DST. When compared with DNA sequencing, the accuracy, positive predictive value (PPV) and negative predictive value (NPV) of the RDBH assay were 97.7%(293/300), 98.2%(164/167), and 97.0%(129/133), respectively. Furthermore, the results indicated that the most common mutations were in codons 531 (48.6%), 526 (25.4%), 516 (8.8%), and 511 (6.6%), and the combinative mutation rate was 15 (8.3%). One and two strains of insertion and deletion were found among all strains, respectively. Conclusion Our findings demonstrate that the RDBH assay is a rapid, simple and sensitive method for diagnosing RIF-resistant tuberculosis.

  19. Evaluation of an enzyme-linked immunoelectrotransfer blot test for the confirmatory serodiagnosis of human toxocariasis

    Directory of Open Access Journals (Sweden)

    William H Roldán

    2009-05-01

    Full Text Available To improve the serodiagnosis of human toxocariasis, a sensitive and specific enzyme-linked immunoelectrotransfer blot (EITB-IgG test was developed and evaluated using Toxocara canislarvae excretory-secretory antigens for detecting anti-Toxocara IgG antibodies. The EITB-IgG profile of toxocariasis was characterized by comparing 27 sera from patients with toxocariasis, 110 sera from healthy subjects and 186 sera from patients with other helminth diseases (ascariasis, ancylostomiasis, trichuriasis, enterobiasis, strongyloidiasis, hymenolepiasis, diphyllobothriasis, taeniasis, cysticercosis, hydatidosis and fascioliasis. Antigenic bands of 24, 28, 30, 35, 56, 117, 136 and 152 kDa were predominantly recognized in sera from all patients with toxocariasis. However, only bands of 24-35 kDa were highly specific for Toxocara infection (98.3%, whereas other antigenic bands observed displayed cross-reactivity. Additionally, when the results of the EITB-IgG test were compared to those of the ELISA-IgG test, a 100% concordance was observed for positive results in human toxocariasis cases. The concordance for negative results between the two tests for healthy subjects and patients with other helminth diseases were 96.3% and 53.7%, respectively, showing that the EITB-IgG test has a higher specificity than ELISA. In conclusion, the EITB-IgG test is a very useful tool to confirm the serological diagnosis of human toxocariasis.

  20. Evaluation of an enzyme-linked immunoelectrotransfer blot test for the confirmatory serodiagnosis of human toxocariasis.

    Science.gov (United States)

    Roldán, William H; Espinoza, Yrma A

    2009-05-01

    To improve the serodiagnosis of human toxocariasis, a sensitive and specific enzyme-linked immunoelectrotransfer blot (EITB-IgG) test was developed and evaluated using Toxocara canislarvae excretory-secretory antigens for detecting anti-Toxocara IgG antibodies. The EITB-IgG profile of toxocariasis was characterized by comparing 27 sera from patients with toxocariasis, 110 sera from healthy subjects and 186 sera from patients with other helminth diseases (ascariasis, ancylostomiasis, trichuriasis, enterobiasis, strongyloidiasis, hymenolepiasis, diphyllobothriasis, taeniasis, cysticercosis, hydatidosis and fascioliasis). Antigenic bands of 24, 28, 30, 35, 56, 117, 136 and 152 kDa were predominantly recognized in sera from all patients with toxocariasis. However, only bands of 24-35 kDa were highly specific for Toxocara infection (98.3%), whereas other antigenic bands observed displayed cross-reactivity. Additionally, when the results of the EITB-IgG test were compared to those of the ELISA-IgG test, a 100% concordance was observed for positive results in human toxocariasis cases. The concordance for negative results between the two tests for healthy subjects and patients with other helminth diseases were 96.3% and 53.7%, respectively, showing that the EITB-IgG test has a higher specificity than ELISA. In conclusion, the EITB-IgG test is a very useful tool to confirm the serological diagnosis of human toxocariasis.

  1. Nanoparticle-based CT imaging technique for longitudinal and quantitative stem cell tracking within the brain: application in neuropsychiatric disorders.

    Science.gov (United States)

    Betzer, Oshra; Shwartz, Amit; Motiei, Menachem; Kazimirsky, Gila; Gispan, Iris; Damti, Efrat; Brodie, Chaya; Yadid, Gal; Popovtzer, Rachela

    2014-09-23

    A critical problem in the development and implementation of stem cell-based therapy is the lack of reliable, noninvasive means to image and trace the cells post-transplantation and evaluate their biodistribution, final fate, and functionality. In this study, we developed a gold nanoparticle-based CT imaging technique for longitudinal mesenchymal stem cell (MSC) tracking within the brain. We applied this technique for noninvasive monitoring of MSCs transplanted in a rat model for depression. Our research reveals that cell therapy is a potential approach for treating neuropsychiatric disorders. Our results, which demonstrate that cell migration could be detected as early as 24 h and up to one month post-transplantation, revealed that MSCs specifically navigated and homed to distinct depression-related brain regions. We further developed a noninvasive quantitative CT ruler, which can be used to determine the number of cells residing in a specific brain region, without tissue destruction or animal scarification. This technique may have a transformative effect on cellular therapy, both for basic research and clinical applications.

  2. Development of a cell culture surface conversion technique using alginate thin film for evaluating effect upon cellular differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Nakashima, Y., E-mail: yuta-n@mech.kumamoto-u.ac.jp [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto 096-8555 (Japan); Graduate School of Science and Engineering, Yamaguchi University, 2-16-1 Tokiwadai, Ube 755-8611 (Japan); Tsusu, K.; Minami, K. [Graduate School of Science and Engineering, Yamaguchi University, 2-16-1 Tokiwadai, Ube 755-8611 (Japan); Nakanishi, Y. [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto 096-8555 (Japan)

    2014-06-15

    Here, we sought to develop a cell culture surface conversion technique that would not damage living cells. An alginate thin film, formed on a glass plate by spin coating of sodium alginate solution and dipping into calcium chloride solution, was used to inhibit adhesion of cells. The film could be removed by ethylenediaminetetraacetate (EDTA) at any time during cell culture, permitting observation of cellular responses to conversion of the culture surface in real time. Additionally, we demonstrated the validity of the alginate thin film coating method and the performance of the film. The thickness of the alginate thin film was controlled by varying the rotation speed during spin coating. Moreover, the alginate thin film completely inhibited the adhesion of cultured cells to the culture surface, irrespective of the thickness of the film. When the alginate thin film was removed from the culture surface by EDTA, the cultured cells adhered to the culture surface, and their morphology changed. Finally, we achieved effective differentiation of C2C12 myoblasts into myotube cells by cell culture on the convertible culture surface, demonstrating the utility of our novel technique.

  3. Lorentz boosted frame simulation technique in Particle-in-cell methods

    Science.gov (United States)

    Yu, Peicheng

    In this dissertation, we systematically explore the use of a simulation method for modeling laser wakefield acceleration (LWFA) using the particle-in-cell (PIC) method, called the Lorentz boosted frame technique. In the lab frame the plasma length is typically four orders of magnitude larger than the laser pulse length. Using this technique, simulations are performed in a Lorentz boosted frame in which the plasma length, which is Lorentz contracted, and the laser length, which is Lorentz expanded, are now comparable. This technique has the potential to reduce the computational needs of a LWFA simulation by more than four orders of magnitude, and is useful if there is no or negligible reflection of the laser in the lab frame. To realize the potential of Lorentz boosted frame simulations for LWFA, the first obstacle to overcome is a robust and violent numerical instability, called the Numerical Cerenkov Instability (NCI), that leads to unphysical energy exchange between relativistically drifting particles and their radiation. This leads to unphysical noise that dwarfs the real physical processes. In this dissertation, we first present a theoretical analysis of this instability, and show that the NCI comes from the unphysical coupling of the electromagnetic (EM) modes and Langmuir modes (both main and aliasing) of the relativistically drifting plasma. We then discuss the methods to eliminate them. However, the use of FFTs can lead to parallel scalability issues when there are many more cells along the drifting direction than in the transverse direction(s). We then describe an algorithm that has the potential to address this issue by using a higher order finite difference operator for the derivative in the plasma drifting direction, while using the standard second order operators in the transverse direction(s). The NCI for this algorithm is analyzed, and it is shown that the NCI can be eliminated using the same strategies that were used for the hybrid FFT

  4. Radio Resource Management Techniques for eMBB and mMTC services in 5G Dense Small Cell Scenarios

    DEFF Research Database (Denmark)

    Mahmood, Nurul Huda; Lauridsen, Mads; Berardinelli, Gilberto;

    2016-01-01

    Research in 5G has so far been aimed towards laying out a conceptual vision and the engineering requirements. The focus is now shifting towards standardization through evaluation of potential solutions. 5G wireless communication system is expected to serve a diverse range of services with different...... design requirements. Dense small cells with multiple antenna nodes are believed to be key elements in meeting these challenging requirements. 5G will thus feature an adaptable air interface with carefully designed radio resource management techniques that can optimize each link according to its service...... requirements. This article provides an overview of key radio resource management techniques for 5G dense small cells and demonstrates how these techniques can contribute to fulfilling some of the important 5G requirements. Preliminary system level simulation results indicate that a mean throughput gain...

  5. New views of the human NK cell immunological synapse: recent advances enabled by super- and high- resolution imaging techniques

    Directory of Open Access Journals (Sweden)

    Emily M. Mace

    2013-01-01

    Full Text Available Imaging technology has undergone rapid growth with the development of super resolution microscopy, which enables resolution below the diffraction barrier of light (~200 nm. In addition, new techniques for single molecule imaging are being added to the cell biologist’s arsenal. Immunologists have exploited these techniques to advance understanding of NK biology, particularly that of the immune synapse. The immune synapse’s relatively small size and complex architecture combined with its exquisitely controlled signaling milieu have made it a challenge to visualize. In this review we highlight and discuss new insights into NK cell immune synapse formation and regulation revealed by cutting edge imaging techniques, including super resolution microscopy and high resolution total internal reflection microscopy and Förster resonance energy transfer.

  6. Basal cell carcinoma of the outer nose: Overview on surgical techniques and analysis of 312 patients

    Directory of Open Access Journals (Sweden)

    Uwe Wollina

    2014-01-01

    Full Text Available Background: Basal cell carcinoma of the nose is common, with a potential of local recurrence and high-risk features. Materials and Methods: We provide a review on anatomy of the nose, tumour surgery and defect closure on the nose. We analysed our own patients with nasal BCC of a 24 months period. Results: We identified 321 patients with nasal BCC. There was a predominance of female patients of 1.2 to 1. The mean age was 74.8 years. Slow Mohs technique was employed for all tumours until 3D tumour-free margins were achieved. That resulted on average in 1.8 ± 0.7 Mohs stages. The most common histologic types were solitary (n = 182, morpheic (79, and micronodular (20, Perineural infiltration was evident in 56 tumours. Primary closure after mobilisation of soft tissue was possible in 105 BCCs. Advancement flaps were used in 91 tumours, rotation flaps in 47, transposition flaps in 34 tumours, and combined procedures in 6 cases. In 36 patients full-thickness skin grafting was performed. In two patients healing by second intention was preferred. Partial flap loss was seen in four patients (1.4%. All of them had significant underlying pathologies. None of the tumours treated showed a relapse during the observation time. However, this is a limitation of the present study since follow-up was on average only 10 months. Conclusions: BCCs of the nose are common. Only 3D-controlled micrographic surgery (Mohs or slow Mohs guarantee a high rate of complete tumour removal and a very low risk of recurrence.

  7. [THE NEW APPROACH TO EVALUATION OF ENDOTHELIUM DYSFUNCTION: DETECTION OF NUMBER OF CIRCULATING ENDOTHELIUM CELLS USING FLOW CYTOMETRY TECHNIQUE].

    Science.gov (United States)

    Feoktistova, V S; Vavilkova, T V; Sirotkina, O V; Boldueva, S A; Gaikovaia, L B; Leonova, I A; Laskovets, A B; Ermakov, A I

    2015-04-01

    The endothelium dysfunction takes leading place in pathogenesis of development of cardiovascular diseases. The circulating endothelium cells of peripheral blood can act as a direct cell marker of damage and remodeling of endothelium. The study was carried out to develop a new approach to diagnose of endothelium dysfunction by force of determination of number of circulating endothelium cells using flow cytometry technique and to apply determination of circulating endothelium cells for evaluation of risk of development of ischemic heart disease in women of young and middle age. The study embraced 62 female patients with angiography confirmed ischemic heart disease, exertional angina pectoris at the level of functional class I-II (mean age 51 ± 6 years) and 49 women without anamnesis of ischemic heart disease (mean age 52 ± 9 years). The occurrence of more than three circulating endothelium cells by 3 x 105 leukocytes in peripheral blood increases relative risk of development of ischemic heart disease up to 4 times in women of young and middle age and risk of development of acute myocardial infarction up to 8 times in women with ischemic heart disease. The study demonstrated possibility to apply flow cytometry technique to quantitatively specify circulating endothelium cells in peripheral blood and forecast risk of development of ischemic heart disease in women of young and middle age depending on level of circulating endothelium cells.

  8. Treatment of bladder dysfunction using stem cell or tissue engineering technique.

    Science.gov (United States)

    Kim, Jae Heon; Lee, Hong Jun; Song, Yun Seob

    2014-04-01

    Tissue engineering and stem cell transplantation are two important options that may help overcome limitations in the current treatment strategy for bladder dysfunction. Stem cell therapy holds great promise for treating pathophysiology, as well as for urological tissue engineering and regeneration. To date, stem cell therapy in urology has mainly focused on oncology and erectile dysfunction. The therapeutic potency of stem cells (SCs) was originally thought to derive from their ability to differentiate into various cell types including smooth muscle. The main mechanisms of SCs in reconstituting or restoring bladder function are migration, differentiation, and paracrine effects. Nowadays, paracrine effects of stem cells are thought to be more prominent because of their stimulating effects on stem cells and adjacent cells. Studies of stem cell therapy for bladder dysfunction have been limited to experimental models and have been less focused on tissue engineering for bladder regeneration. Bladder outlet obstruction is a representative model. Adipose-derived stem cells, bone marrow stem cells (BMSCs), and skeletal muscle-derived stem cells or muscle precursor cells are used for transplantation to treat bladder dysfunction. The aim of this study is to review stem cell therapy and updated tissue regeneration as treatments for bladder dysfunction and to provide the current status of stem cell therapy and tissue engineering for bladder dysfunction including its mechanisms and limitations.

  9. Electrostatic protein immobilization using charged polyacrylamide gels and cationic detergent microfluidic Western blotting.

    Science.gov (United States)

    Kim, Dohyun; Karns, Kelly; Tia, Samuel Q; He, Mei; Herr, Amy E

    2012-03-06

    We report a novel protein immobilization matrix for fully integrated microfluidic Western blotting (WB). The electrostatic immobilization gel (EIG) enables immobilization of all proteins sized using cetyl trimethylammonium bromide polyacrylamide gel electrophoresis (CTAB-PAGE), for subsequent electrophoretic probing with detection affinity reagents (e.g., labeled antibodies). The "pan-analyte" capture strategy introduced here uses polyacrylamide gel grafted with concentrated point charges (zwitterionic macromolecules), in contrast to existing microfluidic WB strategies that rely on a sandwich immunoassay format for analyte immobilization and detection. Sandwich approaches limit analyte immobilization to capture of only a priori known targets. A charge interaction mechanism study supports the hypothesis that electrostatic interaction plays a major role in analyte immobilization on the EIG. We note that protein capture efficiency depends on both the concentration of copolymerized charges and ionic strength of the gel buffer. We demonstrate pan-analyte immobilization of sized CTAB-laden model proteins (protein G, ovalbumin, bovine serum albumin, β-galactosidase, lactoferrin) on the EIG with initial capture efficiencies ranging from 21 to 100%. Target proteins fixed on the EIG (protein G, lactoferrin) are detected using antibody probes with signal-to-noise ratios of 34 to 275. The approach advances protein immunoblotting performance through 200× reduction on sample consumption, 12× reduction in assay duration, and automated assay operation, compared to slab-gel WB. Using the microfluidic WB assay, assessment of lactoferrin in human tear fluid is demonstrated with a goal of advancing toward nonbiopsy-based diagnosis of Sjögren's Syndrome, an autoimmune disease.

  10. Evaluation of a Western Blot Test in an Outbreak of Acute Pulmonary Histoplasmosis

    Science.gov (United States)

    Pizzini, Claudia V.; Zancopé-Oliveira, Rosely M.; Reiss, Errol; Hajjeh, Rana; Kaufman, Leo; Peralta, José Mauro

    1999-01-01

    A western blot (WB) test was evaluated for detection of antibodies against native glycosylated and chemically deglycosylated M and H antigens of Histoplasma capsulatum in serum obtained from patients during the acute phase of pulmonary histoplasmosis that occurred during an outbreak. Of 275 serum samples tested by immunodiffusion and complement fixation (CF) samples from 40 patients affected during this outbreak and from 37 negative controls were tested by WB test. A group of patients whose sera were negative for CF antibodies and precipitins early in the acute stage of histoplasmosis but who all seroconverted during convalescence 6 weeks later were tested with the WB test. Antibodies against untreated H and M antigens were detected at a 1:100 dilution by WB test in 45% of the 20 acute-phase serum samples and in all 20 of the convalescent-phase specimens. The WB test’s sensitivity for acute-phase specimens increased to 90% (18 of 20 specimens) when H and M antigens were treated by periodate oxidation to inactivate susceptible carbohydrate epitopes. When native glycosylated antigens were used in the WB test, positive reactions were observed in negative control serum specimens (3 of 37 specimens; 8%) and in serum specimens obtained from asymptomatic persons screened as part of the outbreak investigation (13 of 20 specimens; 65%). These positive reactions were also attributed to glycosidic epitopes since the specificity of the WB test increased from 78 to 100% when periodate-treated H and M antigens were used. WB test with deglycosylated H and M antigens of histoplasmin provides a rapid, sensitive, and specific test to diagnose acute pulmonary histoplasmosis before precipitins can be detected. PMID:9874658

  11. Molecular diagnosis of Theileria and Babesia species infecting cattle in Northern Spain using reverse line blot macroarrays

    Directory of Open Access Journals (Sweden)

    Juste Ramón A

    2006-05-01

    Full Text Available Abstract Background Piroplasmosis in cattle is caused by tick-borne haemoprotozoan parasites of the genera Theileria and Babesia. Molecular detection techniques offer higher sensitivity and specificity than microscopy examination methods and serological tests. A reverse line blot (RLB macroarray that included generic and species-specific probes for Theileria annulata, Theileria buffeli, Babesia bovis, Babesia bigemina, Babesia divergens and Babesia major was used to study the presence and identity of the piroplasm species infecting 263 bovine blood samples from 79 farms, most of them in Northern Spain. Microscopy examination of blood smears and haematology were also performed whenever possible to identify animals with parasitaemia. Results RLB hybridisation identified infection in 54.0% of the samples, whereas only 28.8% were positive by microscopy examination. The most frequently found species was T. buffeli, present in 42.6% of the samples. T. annulata was found in 22 samples (8.4% from 12 farms, including 9 farms (14 samples located in Northern Spain where presence of the vector is not very common. Babesia infections were less frequently detected: B. major was found in 3.0% of the samples, B. bigemina in 2.7%, B. bovis in 2.3% and B. divergens in 1.1%. Mixed infections were detected in 14 samples, accounting for six different combinations of species. Conclusion This is the first report in which B. major and B. divergens have been detected in Spain using molecular identification techniques and the first time that B. bovis has been detected in Northern Spain. The detection of T. annulata in Northern Spain suggests that the distribution of Mediterranean theileriosis might be changing. Samples with positive RLB hybridisation but negative microscopy had haematology values within the normal ranges suggesting that they corresponded to chronic carriers that may serve as reservoirs of the infection. In this sense, sensitive and specific laboratorial

  12. Evaluation of two sets of immunohistochemical and Western blot confirmatory methods in the detection of typical and atypical BSE cases

    Directory of Open Access Journals (Sweden)

    Greenlee Justin J

    2011-09-01

    Full Text Available Abstract Background Three distinct forms of bovine spongiform encephalopathy (BSE, defined as classical (C-, low (L- or high (H- type, have been detected through ongoing active and passive surveillance systems for the disease. The aim of the present study was to compare the ability of two sets of immunohistochemical (IHC and Western blot (WB BSE confirmatory protocols to detect C- and atypical (L- and H-type BSE forms. Obex samples from cases of United States and Italian C-type BSE, a U.S. H-type and an Italian L-type BSE case were tested in parallel using the two IHC sets and WB methods. Results The two IHC techniques proved equivalent in identifying and differentiating between C-type, L-type and H-type BSE. The IHC protocols appeared consistent in the identification of PrPSc distribution and deposition patterns in relation to the BSE type examined. Both IHC methods evidenced three distinct PrPSc phenotypes for each type of BSE: prevailing granular and linear tracts pattern in the C-type; intraglial and intraneuronal deposits in the H-type; plaques in the L-type. Also, the two techniques gave comparable results for PrPSc staining intensity on the C- and L-type BSE samples, whereas a higher amount of intraglial and intraneuronal PrPSc deposition on the H-type BSE case was revealed by the method based on a stronger demasking step. Both WB methods were consistent in identifying classical and atypical BSE forms and in differentiating the specific PrPSc molecular weight and glycoform ratios of each form. Conclusions The study showed that the IHC and WB BSE confirmatory methods were equally able to recognize C-, L- and H-type BSE forms and to discriminate between their different immunohistochemical and molecular phenotypes. Of note is that for the first time one of the two sets of BSE confirmatory protocols proved effective in identifying the L-type BSE form. This finding helps to validate the suitability of the BSE confirmatory tests for BSE

  13. Ex vivo hyperpolarized MR spectroscopy on isolated renal tubular cells: A novel technique for cell energy phenotyping

    DEFF Research Database (Denmark)

    Juul, Troels; Palm, Fredrik; Nielsen, Per Mose;

    2016-01-01

    ) C MR is suitable for cells isolated from kidney tissue, without prior cell culture. METHODS: Isolation of tubular cells from freshly excised kidney tissue and treatment with either ouabain or antimycin A was investigated with hyperpolarized MR spectroscopy on a 9.4 Tesla preclinical imaging system...

  14. Genetic Manipulation of NK Cells for Cancer Immunotherapy: Techniques and Clinical Implications.

    Science.gov (United States)

    Carlsten, Mattias; Childs, Richard W

    2015-01-01

    Given their rapid and efficient capacity to recognize and kill tumor cells, natural killer (NK) cells represent a unique immune cell to genetically reprogram in an effort to improve the outcome of cell-based cancer immunotherapy. However, technical and biological challenges associated with gene delivery into NK cells have significantly tempered this approach. Recent advances in viral transduction and electroporation have now allowed detailed characterization of genetically modified NK cells and provided a better understanding for how these cells can be utilized in the clinic to optimize their capacity to induce tumor regression in vivo. Improving NK cell persistence in vivo via autocrine IL-2 and IL-15 stimulation, enhancing tumor targeting by silencing inhibitory NK cell receptors such as NKG2A, and redirecting tumor killing via chimeric antigen receptors, all represent approaches that hold promise in preclinical studies. This review focuses on available methods for genetic reprograming of NK cells and the advantages and challenges associated with each method. It also gives an overview of strategies for genetic reprograming of NK cells that have been evaluated to date and an outlook on how these strategies may be best utilized in clinical protocols. With the recent advances in our understanding of the complex biological networks that regulate the ability of NK cells to target and kill tumors in vivo, we foresee genetic engineering as an obligatory pathway required to exploit the full potential of NK-cell based immunotherapy in the clinic.

  15. Analysis of caspase-3 in ASTC-a-1 cells treated with mitomycin C using acceptor photobleaching techniques

    Science.gov (United States)

    Wang, Huiying; Chen, Tongsheng; Sun, Lei

    2008-02-01

    Caspase-3 is a key activated death protease, which catalyzes the specific cleavage of many cellular proteins and induces DNA cleavage eventually. In this report, cells were treated with mitomycin C (MMC) at different concentration and its activity was detected by cell counting kit (CCK-8). Based on results of CCK-8, cells were treated with 10μg/mL MMC and Hoechst 33258 has been used to observe cell apoptosis. Fluorescence resonance energy transfer (FRET) and confocal microscopy have been used to the effect of MMC on the caspase3 activation in living cells. Human lung adenocarcinoma cells (ASTC-a-1) was transfected with plasmid SCAT3 (pSCAT3)/CKAR FRET receptor. Acceptor photobleaching techniques of FRET plasmid has been used to destruct fluorophore of cells stably expressing SCAT3 reporter on a fluorescence confocal microscope. The activity of caspase3 can be analyzed by FRET dynamics of SCAT3 in living cells. Our results show that MM C can induce ASTC-a-1 cell apoptosis through activation of caspase3.

  16. Shot number estimation for EB direct writing for logic LSI utilizing character-build standard-cell layout technique

    Science.gov (United States)

    Kajiya, Yoshihiko; Nakamura, Akihiro; Yoshikawa, Masaya; Fujino, Takeshi

    2006-05-01

    Electron Beam direct writing (EBDW) technology is the most cost-effective lithography tool for small-volume logic-LSI fabrication. The EB exposure time will be greatly reduced by applying character-projection (CP) aperture. But the applicable number of CP aperture is limited to 25-400 depending upon EB lithography apparatus. The cell-based logic LSIs are composed of standard-cells (SCs) whose number is 400-1000. Therefore, it is impossible to implement all SCs as CP apertures, because the SCs are placed to 4-directions in general. We had proposed the new technique named 'Character-Build (CB) standard-cell', and demonstrate the most of the combination-logic SCs can be composed by only 17 CP apertures. In this paper, not only combination-logic SCs but also sequential-logic SCs are considered. The number of EB-shots and the chip-area are estimated for some sample circuits. Compared to the simply-limited SCs, The EB shot number is 30-40% reduced by using proposed CB standard-cell, when the CP aperture numbers are 20-30. Moreover, CB standard-cell was advantageous in the module area. Considering 2-directional placement of SCs, the combination of the EB apparatus with 50-100 CP apertures and the CB standard-cell technique may be the best method for high-speed EB direct-writing.

  17. Detection of classical and atypical/Nor98 scrapie by the paraffin-embedded tissue blot method.

    Science.gov (United States)

    Wemheuer, W M; Benestad, S L; Wrede, A; Wemheuer, W E; Brenig, B; Bratberg, B; Schulz-Schaeffer, W J

    2009-05-30

    The paraffin-embedded tissue (PET) blot method was used to investigate sections of the central nervous system and lymphatic tissues from 24 cases of classical scrapie and 25 cases of atypical/Nor98 scrapie in sheep and four healthy control sheep. The PET blot detected deposits of PrP(Sc) in the brain tissue of all 49 sheep with scrapie but no PrP(Sc) labelling could be detected in the control sheep. By contrast, not all the atypical/Nor98 scrapie cases were detectable by immunohistochemistry. The high sensitivity of the PET blot method made it possible to observe that in some atypical/Nor98 cases, deposits of PrP(Sc) may be restricted to supratentorial brain structures and that the diagnosis may be missed when only testing the obex area, where deposits are common in classical scrapie, and the cerebellar structures, where deposits are considered to be common in atypical/Nor98 cases.

  18. A slot blot immunoassay for quantitative detection of Plasmodium falciparum circumsporozoite protein in mosquito midgut oocyst.

    Directory of Open Access Journals (Sweden)

    Sanjai Kumar

    Full Text Available There is still a need for sensitive and reproducible immunoassays for quantitative detection of malarial antigens in preclinical and clinical phases of vaccine development and in epidemiology and surveillance studies, particularly in the vector host. Here we report the results of sensitivity and reproducibility studies for a research-grade, quantitative enhanced chemiluminescent-based slot blot assay (ECL-SB for detection of both recombinant Plasmodium falciparum circumsporozoite protein (rPfCSP and native PfCSP from Oocysts (Pf Oocyst developing in the midguts of Anopheles stephensi mosquitoes. The ECL-SB detects as little as 1.25 pg of rPfCSP (linear range of quantitation 2.5-20 pg; R2 = 0.9505. We also find the earliest detectable expression of native PfCSP in Pf Oocyst by ECL-SB occurs on day 7 post feeding with infected blood meal. The ECL-SB was able to detect approximately as few as 0.5 day 8 Pf Oocysts (linear quantitation range 1-4, R2 = 0.9795 and determined that one Pf Oocyst expressed approximately 2.0 pg (0.5-3 pg of native PfCSP, suggesting a similar range of detection for recombinant and native forms of Pf CSP. The ECL-SB is highly reproducible; the Coefficient of Variation (CV for inter-assay variability for rPf CSP and native PfCSP were 1.74% and 1.32%, respectively. The CVs for intra-assay variability performed on three days for rPf CSP were 2.41%, 0.82% and 2% and for native Pf CSP 1.52%, 0.57%, and 1.86%, respectively. In addition, the ECL-SB was comparable to microscopy in determining the P. falciparum prevalence in mosquito populations that distinctly contained either high and low midgut Pf Oocyst burden. In whole mosquito samples, estimations of positivity for P. falciparum in the high and low burden groups were 83.3% and 23.3% by ECL-SB and 85.7% and 27.6% by microscopy. Based on its performance characteristics, ECL-SB could be valuable in vaccine development and to measure the parasite prevalence in mosquitoes

  19. Evaluation of the Cell Proliferation Process of Ovarian Follicles in Hypothyroid Rats by Proliferation Cell Nuclear Antigen Immunohistochemical Technique

    Directory of Open Access Journals (Sweden)

    M. Moghaddam Dorafshani

    2012-10-01

    Full Text Available Introduction & Objective: The normal females reproductive function , needs hypothalamus-hypophysis-ovarian extensive hormonal messages. Primary hypothyroidism is characterized by reduced production and secretion of thyroid hormones. During follicular growth PCNA (Proliferating Cell Nuclear Antigen and cycklin D complex play an important role in regulating cell proliferation .This study aimed to determine the cell proliferation index and how this process changes induced by thyroid hormone decreased in rat ovarian follicles.Materials & Methods: In this experimental study, 20 Wistar female rats were divided into experimental and control groups. Experimental group was chemically thyroidectomized by administering propylthiouracil (PTU (500 mg per liter of drinking water. The control group received normal drinking water. After three weeks rats were killed and their ovaries dissected and fixed for the histological preparation. Cell proliferation was determined by PCNA and stereological methods were used for counting cells.Results: Cell proliferation index showed a significant decrease in the frequency of follicular growth from prenatal to graafian follicles in hypothyroidism groups(P0.05 . PCNA expression determined that Primary follicle growth begins earlier. Positive PCNA cells were not observed in primordial follicles of the groups.Conclusion: According to the results of our study, this hypothesis is raised that granulosa cells in growing follicles may be increased by follicle adjacent cells in ovarian stroma . Hormonal changes following the reduction of thyroid hormones may greatly affect the cell proliferation index and lead to faster follicle degeneration.(Sci J Hamadan Univ Med Sci 2012; 19 (3:5-15

  20. A new technique to measure the neutralizer cell gas line density applied to a DIII-D neutral beamline

    Energy Technology Data Exchange (ETDEWEB)

    Kessler, D.N.; Hong, R.M.; Riggs, S.P.

    1995-10-01

    The DIII-D tokamak employs eight ion sources for plasma heating. In order to obtain the maximum neutralization of energetic ions (providing maximum neutral beam power) and reduce the heat load on beamline internal components caused by residual energetic ions, sufficient neutral gas must be injected into the beamline neutralizer cell. The neutral gas flow rate must be optimized, however, since excessive gas will increase power losses due to neutral beam scattering and reionization. It is important, therefore, to be able to determine the neutralizer cell gas line density. A new technique which uses the ion source suppressor grid current to obtain the neutralizer cell gas line density has been developed. The technique uses the fact that slow ions produced by beam-gas interactions in the neutralizer cell during beam extraction are attracted to the negative potential applied to the suppressor grid, inducing current flow in the grid. By removing the dependence on beam energy and beam current a normalized suppressor grid current function can be formed which is dependent only on the gas line density. With this technique it is possible to infer the gas line density on a shot by shot basis.

  1. Performance improvement of n-i-p μc-Si:H solar cells by gradient hydrogen dilution technique

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    High pressure radio frequency plasma enhanced chemical vapor deposition(RF-PECVD)process was adopted to investigate the effect of constant hydrogen dilution technique and gradient hydrogen dilu-tion technique on the structural evolution of intrinsic films and the performance of n-i-p microcrystal-line silicon solar cells.The experiment results demonstrated that the grain size and crystalline volume fraction along the growth direction of intrinsic films can be controlled and the performance of solar cells can be greatly improved by gradient hydrogen dilution technique.An initial active-area efficiency of 5.7%(Voc=0.47V,Jsc=20.2mA/cm2,FF=60%)for the μc-Si:H single-junction n-i-p solar cells and an initial active-area efficiency of 10.12%(Voc=1.2V,Jsc=12.05mA/cm2,FF=70%)for the a-Si:H/μc-Si:H tandem n-i-p solar cells has been achieved.

  2. MIMO wireless networks channels, techniques and standards for multi-antenna, multi-user and multi-cell systems

    CERN Document Server

    Clerckx, Bruno

    2013-01-01

    This book is unique in presenting channels, techniques and standards for the next generation of MIMO wireless networks. Through a unified framework, it emphasizes how propagation mechanisms impact the system performance under realistic power constraints. Combining a solid mathematical analysis with a physical and intuitive approach to space-time signal processing, the book progressively derives innovative designs for space-time coding and precoding as well as multi-user and multi-cell techniques, taking into consideration that MIMO channels are often far from ideal. Reflecting developments

  3. Optimal Materials and Deposition Technique Lead to Cost-Effective Solar Cell with Best-Ever Conversion Efficiency (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2012-07-01

    This fact sheet describes how the SJ3 solar cell was invented, explains how the technology works, and why it won an R&D 100 Award. Based on NREL and Solar Junction technology, the commercial SJ3 concentrator solar cell - with 43.5% conversion efficiency at 418 suns - uses a lattice-matched multijunction architecture that has near-term potential for cells with {approx}50% efficiency. Multijunction solar cells have higher conversion efficiencies than any other type of solar cell. But developers of utility-scale and space applications crave even better efficiencies at lower costs to be both cost-effective and able to meet the demand for power. The SJ3 multijunction cell, developed by Solar Junction with assistance from foundational technological advances by the National Renewable Energy Laboratory, has the highest efficiency to date - almost 2% absolute more than the current industry standard multijunction cell-yet at a comparable cost. So what did it take to create this cell having 43.5% efficiency at 418-sun concentration? A combination of materials with carefully designed properties, a manufacturing technique allowing precise control, and an optimized device design.

  4. Admission Cell Free DNA as a Prognostic Factor in Burns: Quantification by Use of a Direct Rapid Fluorometric Technique

    Directory of Open Access Journals (Sweden)

    Yaron Shoham

    2014-01-01

    Full Text Available Background. Despite great advances in the treatment of burn patients, useful prognostic markers are sparse. During the past years there has been increasing interest in circulating plasma cell free DNA as a potential marker for tissue injury. We have developed a rapid direct fluorescent assay for cell free DNA quantification that allows obtaining accurate, fast, and inexpensive measurements. Objective. To use this technique for measuring plasma cell free DNA levels in burn patients and to further explore the use of cell free DNA as a potential marker of patient outcome in burns. Methods. Cell free DNA levels obtained from 14 burn victims within 6 hours of injury and 14 healthy controls were quantified by a direct rapid fluorometric assay. Results. Patient admission cell free DNA levels were significantly elevated compared with that of controls (1797 ± 1523 ng/mL versus 374 ± 245 ng/mL, P=0.004. There are statistically significant correlations between cell free DNA admission levels and burn degree (Spearman’s correlation = 0.78, P=0.001, total body surface area (Spearman’s correlation = 0.61, P=0.02, and total burn volume (Spearman’s correlation = 0.64, P=0.014. Conclusions. Admission cell free DNA levels can serve as a prognostic factor in burns and future routine use can be made possible by use of our direct rapid fluorometric assay.

  5. Research Update: Large-area deposition, coating, printing, and processing techniques for the upscaling of perovskite solar cell technology

    Directory of Open Access Journals (Sweden)

    Stefano Razza

    2016-09-01

    Full Text Available To bring perovskite solar cells to the industrial world, performance must be maintained at the photovoltaic module scale. Here we present large-area manufacturing and processing options applicable to large-area cells and modules. Printing and coating techniques, such as blade coating, slot-die coating, spray coating, screen printing, inkjet printing, and gravure printing (as alternatives to spin coating, as well as vacuum or vapor based deposition and laser patterning techniques are being developed for an effective scale-up of the technology. The latter also enables the manufacture of solar modules on flexible substrates, an option beneficial for many applications and for roll-to-roll production.

  6. Probing cell structure responses through a shear and stretching mechanical stimulation technique.

    Science.gov (United States)

    Steward, Robert L; Cheng, Chao-Min; Wang, Danny L; LeDuc, Philip R

    2010-04-01

    Cells are complex, dynamic systems that respond to various in vivo stimuli including chemical, mechanical, and scaffolding alterations. The influence of mechanics on cells is especially important in physiological areas that dictate what modes of mechanics exist. Complex, multivariate physiological responses can result from multi-factorial, multi-mode mechanics, including tension, compression, or shear stresses. In this study, we present a novel device based on elastomeric materials that allowed us to stimulate NIH 3T3 fibroblasts through uniaxial strip stretching or shear fluid flow. Cell shape and structural response was observed using conventional approaches such as fluorescent microscopy. Cell orientation and actin cytoskeleton alignment along the direction of applied force were observed to occur after an initial 3 h time period for shear fluid flow and static uniaxial strip stretching experiments although these two directions of alignment were oriented orthogonal relative to each other. This response was then followed by an increasingly pronounced cell and actin cytoskeleton alignment parallel to the direction of force after 6, 12, and 24 h, with 85% of the cells aligned along the direction of force after 24 h. These results indicate that our novel device could be implemented to study the effects of multiple modes of mechanical stimulation on living cells while probing their structural response especially with respect to competing directions of alignment and orientation under these different modes of mechanical stimulation. We believe that this will be important in a diversity of fields including cell mechanotransduction, cell-material interactions, biophysics, and tissue engineering.

  7. Gelatin-based laser direct-write technique for the precise spatial patterning of cells.

    Science.gov (United States)

    Schiele, Nathan R; Chrisey, Douglas B; Corr, David T

    2011-03-01

    Laser direct-writing provides a method to pattern living cells in vitro, to study various cell-cell interactions, and to build cellular constructs. However, the materials typically used may limit its long-term application. By utilizing gelatin coatings on the print ribbon and growth surface, we developed a new approach for laser cell printing that overcomes the limitations of Matrigel™. Gelatin is free of growth factors and extraneous matrix components that may interfere with cellular processes under investigation. Gelatin-based laser direct-write was able to successfully pattern human dermal fibroblasts with high post-transfer viability (91% ± 3%) and no observed double-strand DNA damage. As seen with atomic force microscopy, gelatin offers a unique benefit in that it is present temporarily to allow cell transfer, but melts and is removed with incubation to reveal the desired application-specific growth surface. This provides unobstructed cellular growth after printing. Monitoring cell location after transfer, we show that melting and removal of gelatin does not affect cellular placement; cells maintained registry within 5.6 ± 2.5 μm to the initial pattern. This study demonstrates the effectiveness of gelatin in laser direct-writing to create spatially precise cell patterns with the potential for applications in tissue engineering, stem cell, and cancer research.

  8. The Application of Load-cell Technique in the Study of Armour Unit Responses to Impact Loads Tests

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Liu, Z.

    1995-01-01

    The slender, complex types of armour units, such as Tetrapods and Dolosse are widely used for rubble mound breakwaters. Many of the recent failures of such structures were caused by unforeseen early breakage of the units, thus revealing an in balance between the strength (structural integrity....... slender armour units can be studied. by load-cell technique. Moreover, the paper presents DoJos design diagrams for the prediction of both breakage and hydraulic stability...

  9. The Application of Load-cell Technique in the Study of Armour Unit Responses to Impact Loads

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Liu, Zhou

    1994-01-01

    The slender, complex types of armour units, such as Tetrapods and Dolosse are widely used for rubble mound breakwaters. Many of the recent failures of such structures were caused by unforeseen early breakage of the units, thus revealing an inbalance between the strength (structural integrity...... on slender armour units can be studied by load-cell technique. Moreover, the paper presents Dolos design diagrams for the prediction of both breakage and hydraulic stability....

  10. Differential voltage analyses of high-power, lithium-ion cells. 1. Technique and application

    Science.gov (United States)

    Bloom, Ira; Jansen, Andrew N.; Abraham, Daniel P.; Knuth, Jamie; Jones, Scott A.; Battaglia, Vincent S.; Henriksen, Gary L.

    The C/25 discharge data from 18650-size cells containing LiNi 0.8Co 0.1Al 0.1O 2 cathode and graphite anode laminates were analyzed through the use of the differential voltage, d V/d Q, curves. Using half-cell data, the peaks in the d V/d Q curve of the full cell data were assigned. Analysis of the relative peak shifts allowed for the determination of the source of capacity fade. For cells formed and aged at 45 °C for 40 weeks (capacity fade = 7.5%), the analysis indicated negligible loss of accessible material at the anode and at the cathode. Capacity loss of the cell could be accounted for, largely, by side reactions at the anode. This type of analysis can be used when the introduction of a reference electrode is difficult or impractical.

  11. Detection of genetically modified microorganisms in soil using the most-probable-number method with multiplex PCR and DNA dot blot.

    Science.gov (United States)

    Yeom, Jinki; Lee, Yunho; Noh, Jaemin; Jung, Jaejoon; Park, Jungsoon; Seo, Hyoju; Kim, Jisun; Han, Jiwon; Jeon, Che Ok; Kim, Taesung; Park, Woojun

    2011-10-01

    The principal objective of this study was to detect genetically modified microorganisms (GMMs) that might be accidentally released into the environment from laboratories. Two methods [plate counting and most-probable-number (MPN)] coupled with either multiplex PCR or DNA dot blots were compared using genetically modified Escherichia coli, Pseudomonas putida, and Acinetobacter oleivorans harboring an antibiotic-resistance gene with additional gfp and lacZ genes as markers. Alignments of sequences collected from databases using the Perl scripting language (Perl API) and from denaturing gradient gel electrophoresis analysis revealed that the gfp, lacZ and antibiotic-resistance genes (kanamycin, tetracycline, and ampicillin) in GMMs differed from the counterpart genes in many sequenced genomes and in soil DNA. Thus, specific multiplex PCR primer sets for detection of plasmid-based gfp and lacZ antibiotic-resistance genes could be generated. In the plate counting method, many antibiotic-resistant bacteria from a soil microcosm grew as colonies on antibiotic-containing agar plates. The multiplex PCR verification of randomly selected antibiotic-resistant colonies with specific primers proved ineffective. The MPN-multiplex PCR method and antibiotic-resistant phenotype could be successfully used to detect GMMs, although this method is quite laborious. The MPN-DNA dot blot method screened more cells at a time in a microtiter plate containing the corresponding antibiotics, and was shown to be a more efficient method for the detection of GMMs in soil using specific probes in terms of labor and accuracy.

  12. Scaling-Up Techniques for the Nanofabrication of Cell Culture Substrates via Two-Photon Polymerization for Industrial-Scale Expansion of Stem Cells

    Directory of Open Access Journals (Sweden)

    Davide Ricci

    2017-01-01

    Full Text Available Stem-cell-based therapies require a high number (106–109 of cells, therefore in vitro expansion is needed because of the initially low amount of stem cells obtainable from human tissues. Standard protocols for stem cell expansion are currently based on chemically-defined culture media and animal-derived feeder-cell layers, which expose cells to additives and to xenogeneic compounds, resulting in potential issues when used in clinics. The two-photon laser polymerization technique enables three-dimensional micro-structures to be fabricated, which we named synthetic nichoids. Here we review our activity on the technological improvements in manufacturing biomimetic synthetic nichoids and, in particular on the optimization of the laser-material interaction to increase the patterned area and the percentage of cell culture surface covered by such synthetic nichoids, from a low initial value of 10% up to 88% with an optimized micromachining time. These results establish two-photon laser polymerization as a promising tool to fabricate substrates for stem cell expansion, without any chemical supplement and in feeder-free conditions for potential therapeutic uses.

  13. Serum detection of IgG antibodies against Demodex canis by western blot in healthy dogs and dogs with juvenile generalized demodicosis.

    Science.gov (United States)

    Ravera, Ivan; Ferreira, Diana; Gallego, Laia Solano; Bardagí, Mar; Ferrer, Lluís

    2015-08-01

    The aim of this study was to investigate the presence of canine immunoglobulins (Ig) G against Demodex proteins in the sera of healthy dogs and of dogs with juvenile generalized demodicosis (CanJGD) with or without secondary pyoderma. Demodex mites were collected from dogs with CanJGD. Protein concentration was measured and a western blot technique was performed. Pooled sera from healthy dogs reacted mainly with antigen bands ranging from 55 to 72 kDa. Pooled sera from dogs with CanJGD without secondary pyoderma reacted either with 10 kDa antigen band or 55 to 72 kDa bands. Pooled sera from dogs with CanJGD with secondary pyoderma reacted only with a 10 kDa antigen band. The results of this study suggest that both healthy dogs and dogs with CanJGD develop a humoral response against different proteins of Demodex canis.

  14. Progress in phototaxis mechanism research and micromanipulation techniques of algae cells

    Institute of Scientific and Technical Information of China (English)

    WEN Chenglu; LI Heng; WANG Pengbo; LI Wei; ZHAO Jingquan

    2007-01-01

    Phototactic movement is a characteristic of some microorganisms' response to light environment. Most of the algae have dramatically phototactic responses, underlying the complicated biological, physical and photochemical mechanisms are involved. With the development of the micro/nano and sensor techniques, great progress has been made in the research of the algae phototaxis. This review article summarizes the progress made in the research on the functional phototactic structures, the mechanisms of photo-response process and photodynamics of phototaxis in algae, and describes the latest developed micro-tracking technique and micromanipulation technique.Moreover, based on our own research results, the potential correlation between the phototaxis and photosynthesis is discussed, and the directions for future research of the phototactic mechanism are proposed.

  15. Experimental models of brain ischemia: a review of techniques, magnetic resonance imaging and investigational cell-based therapies

    Directory of Open Access Journals (Sweden)

    Alessandra eCanazza

    2014-02-01

    Full Text Available Stroke continues to be a significant cause of death and disability worldwide. Although major advances have been made in the past decades in prevention, treatment and rehabilitation, enormous challenges remain in the way of translating new therapeutic approaches from bench to bedside. Thrombolysis, while routinely used for ischemic stroke, is only a viable option within a narrow time window. Recently, progress in stem cell biology has opened up avenues to therapeutic strategies aimed at supporting and replacing neural cells in infarcted areas. Realistic experimental animal models are crucial to understand the mechanisms of neuronal survival following ischemic brain injury and to develop therapeutic interventions. Current studies on experimental stroke therapies evaluate the efficiency of neuroprotective agents and cell-based approaches using primarily rodent models of permanent or transient focal cerebral ischemia. In parallel, advancements in imaging techniques permit better mapping of the spatial-temporal evolution of the lesioned cortex and its functional responses. This review provides a condensed conceptual review of the state of the art of this field, from models and magnetic resonance imaging techniques through to stem cell therapies.

  16. Chosen Aspects Of Investigations Of Solar Cells With The Laser Beam Induced Current Technique

    Directory of Open Access Journals (Sweden)

    Chrobak Łukasz Bartłomiej

    2015-06-01

    Full Text Available This paper presents maps of spatial distributions of the short circuit current Isc(x,y and the open circuit voltage Uoc(x,y of the investigated low cost solar cells. Visible differences in values of these parameters were explained by differences in the serial and shunt resistances determined for different points of solar cells from measurements of I–V characteristics. The spectral dependence of the photo voltage of solar cell is also shown, discussed and interpreted in the model of amorphous and crystal silicon.

  17. A low-cost photovoltaic cell process based on thick film techniques

    Science.gov (United States)

    Mardesich, N.; Pepe, A.; Bunyan, S.; Edwards, B.; Olson, C.

    1980-01-01

    The low-cost, easily automated processing for solar cell fabrication being developed at Spectrolab for the DOE LSA program is described. These processes include plasma-etching, spray-on diffusion sources and antireflective coating, thick film metallization, aluminum back contacts, laser scribing and ultrasonic soldering. The process sequence has been shown to produce solar cells having 15% conversion efficiency at AM1 which meet the cell fabrication budget required for the DOE 1986 cost goal of $0.70 per peak watt in 1980.

  18. Combination of Small Molecule Microarray and Confocal Microscopy Techniques for Live Cell Staining Fluorescent Dye Discovery

    Directory of Open Access Journals (Sweden)

    Attila Bokros

    2013-08-01

    Full Text Available Discovering new fluorochromes is significantly advanced by high-throughput screening (HTS methods. In the present study a combination of small molecule microarray (SMM prescreening and confocal laser scanning microscopy (CLSM was developed in order to discover novel cell staining fluorescent dyes. Compounds with high native fluorescence were selected from a 14,585-member library and further tested on living cells under the microscope. Eleven compartment-specific, cell-permeable (or plasma membrane-targeted fluorochromes were identified. Their cytotoxicity was tested and found that between 1–10 micromolar range, they were non-toxic even during long-term incubations.

  19. Complementary techniques for solid oxide electrolysis cell characterisation at the micro- and nano-scale

    DEFF Research Database (Denmark)

    Wiedenmann, D.; Hauch, Anne; Grobety, B.

    2010-01-01

    High-temperature steam electrolysis by solid oxide electrolysis cells (SOEC) is a method with great potential for transforming clean and renewable energy from non-fossil sources to synthetic fuels such as hydrogen, methane or dimethyl ether, which have been identified as promising alternative...... energy carriers. With the same technology, fuel gas can be used in a very efficient way to reconvert chemically stored energy into electrical energy, since SOECs also work in the reverse mode, operating as solid oxide fuel cells (SOFC). As solid oxide cells (SOC) perform at high-temperatures (700–900 °C...

  20. Monitoring programmed cell death of living plant tissues in microfluidics using electrochemical and optical techniques

    DEFF Research Database (Denmark)

    Mark, Christina; Heiskanen, Arto; Svensson, Birte

    for online, real-time, parallel analysis of important parameters such as redox activity (NADPH:NADP ratio), H2O2 concentration, oxygen consumption, extracellular pH, cell viability and release of target enzymes (α-amylase and limit dextrinase). Probing the intracellular redox activity is of major importance......Programmed cell death (PCD) in plants can influence the outcome of yield and quality of crops through its important role in seed germination and the defence process against pathogens. The main scope of the project is to apply microfluidic cell culture for the measurement of electrochemically......, that the H2O2 concentration changes depending on phytohormone activation or inactivation of aleurone layer metabolism and subsequent PCD3. Currently, we are working on the optimization of an intracellular whole-cell redox activity (NADP:NADPH ratio) assay5 to be able to detect possible changes...

  1. A simple technique for reducing edge effect in cell-based assays.

    Science.gov (United States)

    Lundholt, Betina Kerstin; Scudder, Kurt M; Pagliaro, Len

    2003-10-01

    Several factors are known to increase the noise and variability of cell-based assays used for high-throughput screening. In particular, edge effects can result in an unacceptably high plate rejection rate in screening runs. In an effort to minimize these variations, the authors analyzed a number of factors that could contribute to edge effects in cell-based assays. They found that pre-incubation of newly seeded plates in ambient conditions (air at room temperature) resulted in even distribution of the cells in each well. In contrast, when newly seeded plates were placed directly in the CO(2) incubator, an uneven distribution of cells occurred in wells around the plate periphery, resulting in increased edge effect. Here, the authors show that the simple, inexpensive approach of incubating newly seeded plates at room temperature before placing them in a 37 degrees C CO(2) incubator yields a significant reduction in edge effect.

  2. Ex Vivo Produced Oral Mucosa Equivalent by Using the Direct Explant Cell Culture Technique

    Directory of Open Access Journals (Sweden)

    Kamile Öztürk

    2012-09-01

    Full Text Available Objective: The aim of this study is the histological and immunohistochemical evaluation of ex vivo produced oral mucosal equivalents using keratinocytes cultured by direct explant technique.Material and Methods: Oral mucosa tissue samples were obtained from the keratinized gingival tissues of 14 healthy human subjects. Human oral mucosa keratinocytes from an oral mucosa biopsy specimen were dissociated by the explant technique. Once a sufficient population of keratinocytes was reached, they were seeded onto the type IV collagen coated “AlloDerm” and taken for histological and immunohistochemical examinations at 11 days postseeding of the keratinocytes on the cadaveric human dermal matrix.Results: Histopathologically and immunohistochemically, 12 out of 14 successful ex vivo produced oral mucosa equivalents (EVPOME that consisted of a stratified epidermis on a dermal matrix have been developed with keratinocytes cultured by the explant technique.Conclusion: The technical handling involved in the direct explant method at the beginning of the process has fewer steps than the enzymatic method and use of the direct explant technique protocol for culturing of human oral mucosa keratinocyte may be more adequate for EVPOME production.

  3. Reactive impinging-flow technique for polymer-electrolyte-fuel-cell electrode-defect detection

    Science.gov (United States)

    Zenyuk, Iryna V.; Englund, Nicholas; Bender, Guido; Weber, Adam Z.; Ulsh, Michael

    2016-11-01

    Reactive impinging flow (RIF) is a novel quality-control method for defect detection (i.e., reduction in Pt catalyst loading) in gas-diffusion electrodes (GDEs) on weblines. The technique uses infrared thermography to detect temperature of a nonflammable (catalyst-loading reductions of 25, 50, and 100%) are detected at various webline speeds (3.048 and 9.144 m min-1) and gas flowrates (32.5 or 50 standard L min-1). Furthermore, a model is developed and validated for the technique, and it is subsequently used to optimize operating conditions and explore the applicability of the technique to a range of defects. The model suggests that increased detection can be achieved by recting more of the impinging H2, which can be accomplished by placing blocking substrates on the top, bottom, or both of the GDE; placing a substrate on both results in a factor of four increase in the temperature differential, which is needed for smaller defect detection. Overall, the RIF technique is shown to be a promising route for in-line, high-speed, large-area detection of GDE defects on moving weblines.

  4. Reactive Impinging-Flow Technique for Polymer-Electrolyte-Fuel-Cell Electrode-Defect Detection

    Energy Technology Data Exchange (ETDEWEB)

    Zenyuk, Iryna V.; Englund, Nicholas; Bender, Guido; Weber, Adam Z.; Ulsh, Michael

    2016-11-15

    Reactive impinging flow (RIF) is a novel quality-control method for defect detection (i.e., reduction in Pt catalyst loading) in gas-diffusion electrodes (GDEs) on weblines. The technique uses infrared thermography to detect temperature of a nonflammable (<4% H2) reactive mixture of H2/O2 in N2 impinging and reacting on a Pt catalytic surface. In this paper, different GDE size defects (with catalyst-loading reductions of 25, 50, and 100%) are detected at various webline speeds (3.048 and 9.144 m min-1) and gas flowrates (32.5 or 50 standard L min-1). Furthermore, a model is developed and validated for the technique, and it is subsequently used to optimize operating conditions and explore the applicability of the technique to a range of defects. The model suggests that increased detection can be achieved by recting more of the impinging H2, which can be accomplished by placing blocking substrates on the top, bottom, or both of the GDE; placing a substrate on both results in a factor of four increase in the temperature differential, which is needed for smaller defect detection. Overall, the RIF technique is shown to be a promising route for in-line, high-speed, large-area detection of GDE defects on moving weblines.

  5. Distribution and density of mast cells in camel small intestine and influence of fixation techniques

    Directory of Open Access Journals (Sweden)

    MB Al-Zghoul

    2009-08-01

    Full Text Available This study was carried out to gather species-specific data on mast-cell density and distribution in camel small intestine under different fixation conditions and to elucidate the presence and cross-reactivity of tryptase in the camel small intestine using human specific anti-tryptase antibody. Tissue specimens from the jejunum, duodenum, and ileum were obtained from 9 healthy, 9-12 months old, male camels. Specimens were fixed either with carnoy’s fluid or formalinbuffered solution and stained with either methylene blue or immunohistochemically to identify mast cells. The present study demonstrated for the first time, the presence and cross-reactivity of tryptase in the camel small intestine using a specific mouse anti-human tryptase antibody. Mast cells were detected in all histological layers of the camel small intestine (mucosal, submucosal, muscularis externa and serosa. Among all locations examined in the duodenum, ileum and jejunum, no significant difference was observed in mast-cell counts among the lamina propria, muscularis mucosae, muscularis externa and the serosa. The only significant difference observed was the mast-cell count in submucosa region where the highest and lowest mast count was observed in the jejenual and ileal submucosa, respectively. Significant differences regarding the distribution of mast cell as well as the influence of the fixation method could be observed. This underlines the fact that data regarding mast cell heterogeneity from other species, obtained by different fixation methods, are not comparable. This fact has to be taken into account when evaluating mast cell subtypes under pathological conditions.

  6. Monitoring apoptosis of TK-GFP-expressing ACC-M cells induced by ACV using FRET technique

    Science.gov (United States)

    Xiong, Tao; Zhang, Zhihong; Lin, Juqiang; Yang, Jie; Zeng, Shaoqun; Luo, Qingming

    2006-09-01

    Apoptosis is an evolutionary conserved cellular process that plays an important role during development, but it is also involved in tissue homeostasis and in many diseases. To study the characteristics of suicide gene system of the herpes simplex virus thymidine kinase (HSV-tk) gene in tumor cells and explore the apoptosis phenomena in this system and its effect on the human adenoid cystic carcinoma line ACC-M cell, we detected apoptosis of CD3- (ECFP-CRS-DsRed) and TK-GFP-expressing ACC-M (ACC-M-TK-GFP-CD3) cells induced by acyclovir (ACV) using fluorescence resonance energy transfer (FRET) technique. CD3 is a FRET-based indicator for activity of caspase-3, which is composed of an enhanced cyan fluorescent protein, a caspase-3 sensitive linker, and a red fluorescent protein from Discosoma with efficient maturation property. FRET from ECFP to DsRed could be detected in normal ACC-M-TK-GFP-CD3 cells, and the FRET efficient was remarkably decreased and then disappeared during the cells apoptosis induced by ACV. It was due to the activated caspase-3 cleaved the CD3 fusion protein. In this study, the results suggested that the AVC-induced apoptosis of ACC-M-TK-GFP-CD3 cells was through caspase-3 pathway.

  7. Using a GFP-gene fusion technique to study the cell cycle-dependent distribution of calmodulin in living cells

    Institute of Scientific and Technical Information of China (English)

    李朝军; 吕品; 张东才

    1999-01-01

    In this study, a green fluorescent protein (GFP)-calmodulin (CaM) fusion gene method was used to examine the distribution of calmodulin during various stages of cell cycle. First, it was found that the distribution of CaM in living cells changes with the cell cycle. CaM was found mainly in the cytoplasm during G1 phase. It began to move into the nucleus when the cell entered S phase. At G2 phase, CaM became more concentrated in the nucleus than in cytoplasm. Second, the accumulation of CaM in the nucleus during G2 phase appeared to be related to the onset of mitosis, since inhibiting the activation of CaM at this stage resulted in blocking the nuclear membrane breakdown and chromatin condensation. Finally, after the cell entered mitosis, a high concentration of CaM was found at the polar regions of the mitotic spindle. At this time, inhibiting the activity of CaM would cause a disruption of the spindle structure. The relationship between the stage-specific distribution of CaM and its function in regulat

  8. Cathepsin D Expression in Colorectal Cancer: From Proteomic Discovery through Validation Using Western Blotting, Immunohistochemistry, and Tissue Microarrays

    Directory of Open Access Journals (Sweden)

    Chandra Kirana

    2012-01-01

    Full Text Available Despite recent advances in surgical techniques and therapeutic treatments, survival from colorectal cancer (CRC remains disappointing with some 40–50% of newly diagnosed patients ultimately dying of metastatic disease. Current staging by light microscopy alone is not sufficiently predictive of prognosis and would benefit from additional support from biomarkers in order to stratify patients appropriately for adjuvant therapy. We have identified that cathepsin D expression was significantly greater in cells from invasive front (IF area and liver metastasis (LM than those from main tumour body (MTB. Cathepsin D expression was subsequently examined by immunohistochemistry in tissue microarrays from 119 patients with CRC. Strong expression in tumour cells at the IF did not correlate significantly with any clinico-pathological parameters examined or patient survival. However, cathepsin D expression in cells from the MTB was highly elevated in late stage CRC and showed significant correlation with subsequent distant metastasis and shorter cancer-specific survival. We also found that macrophages surrounding tumour cells stained strongly for cathepsin D but there was no significant correlation found between cathepsin D in macrophages at IF and MTB of CRC patient with the clinic-pathological parameters examined.

  9. PEM fuel cell cost minimization using ``Design For Manufacture and Assembly`` techniques

    Energy Technology Data Exchange (ETDEWEB)

    Lomax, F.D. Jr.; James, B.D. [Directed Technologies, Inc., Arlington, VA (United States); Mooradian, R.P. [Ford Motor Co., Dearborn, MI (United States)

    1997-12-31

    Polymer Electrolyte Membrane (PEM) fuel cells fueled with direct hydrogen have demonstrated substantial technical potential to replace Internal Combustion Engines (ICE`s) in light duty vehicles. Such a transition to a hydrogen economy offers the potential of substantial benefits from reduced criteria and greenhouse emissions as well as reduced foreign fuel dependence. Research conducted for the Ford Motor Co. under a US Department of Energy contract suggests that hydrogen fuel, when used in a fuel cell vehicle (FCV), can achieve a cost per vehicle mile less than or equal to the gasoline cost per mile when used in an ICE vehicle. However, fuel cost parity is not sufficient to ensure overall economic success: the PEM fuel cell power system itself must be of comparable cost to the ICE. To ascertain if low cost production of PEM fuel cells is feasible, a powerful set of mechanical engineering tools collectively referred to as Design for Manufacture and Assembly (DFMA) has been applied to several representative PEM fuel cell designs. The preliminary results of this work are encouraging, as presented.

  10. Assessment by Southern blot analysis of UV-induced damage and repair in human immunoglobulin genes.

    Science.gov (United States)

    Bianchi, M S; Bianchi, N O; de la Chapelle, A

    1990-09-01

    Irradiation of DNA with UV light induces pyrimidine dimers and (6-4) photoproducts. The presence of one of these photolesions in the restriction site of a given endonuclease inhibits DNA cleavage and induces the formation of fragments by incomplete DNA digestion which appear as additional, facultative bands in Southern hybridization autoradiograms. The number and size of these fragments show a positive correlation with the UV dose. The response to UV light of immunoglobulin light-chain constant kappa and heavy-chain constant mu genes was analyzed with 2 specific probes. Constant kappa and mu genes when irradiated as part of the chromatin of living lymphocytes showed a UV sensitivity similar to that of naked DNA. The same genes from granulocytes had 50-60 times lower UV sensitivity. When cells were allowed to repair photolesions for 24 h the facultative bands from granulocytes disappeared indicating that these cells were able to remove photolesions from constant kappa and mu genes. Facultative bands from lymphocytes showed a smaller decrease of density after 24 h repair. This suggests that lymphocytes are less efficient than granulocytes in removing UV damage from constant kappa and mu genes.

  11. The Study on Improved Cryopreservation Technique of The Ultrastructure of Corneal Endothelial Cells

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    The traditional corneal cryopreservation technique was improved. We carried out an experimental study that rabbit corneas were cryop-reserved by using polyvinylpyrolidone (PVP) as cryoprotective agent and dimethlsulfoxide (DMSO) as the control. The endothelia of cryopreserved corneas were evaluated by scanning and transmission electron microscopy and vital staining. The study shows that PVP is an excellent extracellular cryoprotective agent and has the characteristic of low toxicity or no toxicity to co...

  12. Hematopoietic stem cell transplantation monitoring in childhood. Hematological diseases in Serbia: STR-PCR techniques

    Directory of Open Access Journals (Sweden)

    Krstić Aleksandra D.

    2007-01-01

    Full Text Available Hematopoietic stem cell transplantation (HSCT is a very successful method of treatment for children with different aquired or inborn diseases. The main goal of post-transplantation chimerism monitoring in HSCT is to predict negative events (such as disease relapse and graft rejection, in order to intervene with appropriate therapy and improve the probability of long-term DFS (disease free survival. In this context, by quantifying the relative amounts of donor and recipient cells present in the peripheral blood sample, it can be determined if engraftment has taken place at all, or if full or mixed chimerism exists. In a group of patients who underwent hematopoietic stem cell transplantation at the Mother and Child Health Care Institute, we decided to use standard human identfication tests based on multiplex PCR analyses of short tandem repeats (STRs, as they are highly informative, sensitive, and fast and therefore represent an optimal methodological approach to engraftment analysis.

  13. Monitoring programmed cell death of living plant tissues in microfluidics using electrochemical and optical techniques

    DEFF Research Database (Denmark)

    Mark, Christina; Heiskanen, Arto; Svensson, Birte

    sensors and detection systems is that they can be miniaturized, multiplexed and automated without losing their performance making them suitable for integration with microfluidic devices1,2. Combining microfluidics with electrochemical and optical detection allows implementation of a wide range of assays......, and it is planned to integrate this system in the microfluidic device.......Programmed cell death (PCD) in plants can influence the outcome of yield and quality of crops through its important role in seed germination and the defence process against pathogens. The main scope of the project is to apply microfluidic cell culture for the measurement of electrochemically...

  14. A novel technique for making open-cell AI203-ZrO2 ceramic foam with plant seed template

    Institute of Scientific and Technical Information of China (English)

    Yu Jingyuan; Li Qiang; Tang Ji; Sun Xudong; Li Xiaodong

    2010-01-01

    The aim of the present research is to provide a technique for preparing open-cell AI203-ZrO2 ceramic foams with uniform cell size. This technique used plant seeds to array templates and centrifugal slip casting to obtain cell struts with high packing density. Aqueous Al2O3-ZrO2 slurries with up to 50 vol.% solid contents were prepared and the rheological characteristic of the slurries was investigated. Consolidation was performed at an acceleration of 2,860 g for 60 rain. The effect of the characteristic of plant seeds on the drying behavior of Al2O3- ZrO2 green compact was analyzed. The effects of the solid contents of slurries on segregation phenomena ofAl2O3 and ZrO2 particles and green compact uniformity were investigated. The compressive stress-strain curve and deformation behavior of Al2O3-ZrO2 ceramic foams prepared using plant seed template were analyzed. The results showed segregation phenomenon is negligible for highly stable slurry with 50 vol.% solid loading. The prepared cell struts of Al2O3-ZrO2 foams have high green density (61.9% TD), sintered density (99.1% TD) and homogeneous microstructure. When sintered at 1,550 ℃ for 2 h, the cell size of Al2O3-ZrO2 foam is approximately uniform and the diameter is about 1.1 mm. The porosity and compressive strength of sintered products is 66.2% and 5.86 MPa, respectively.

  15. Loading of red blood cells with an analyte-sensitive dye for development of a long-term monitoring technique

    Science.gov (United States)

    Ritter, Sarah C.; Meissner, Kenith E.

    2012-03-01

    Measurement of blood analytes, such as pH and glucose, provide crucial information about a patient's health. Some such analytes, such as glucose in the case of diabetes, require long-term or near-continuous monitoring for proper disease management. However, current monitoring techniques are far from ideal: multiple-per-day finger stick tests are inconvenient and painful for the patient; implantable sensors have short functional life spans (i.e., 3-7 days). Red blood cells serve as an attractive alternative for carriers of analyte sensors. Once reintroduced to the blood stream, these carriers may continue to live for the remainder of their life span (120 days for humans). They are also biodegradable and biocompatible, thereby eliminating the immune system response common for many implanted devices. The proposed carrier system takes advantage of the ability of the red blood cells to swell in response to a decrease in the osmolarity of the extracellular solution. Just before the membranes lyse, they develop small pores on the scale of tens of nanometers. Analyte-sensitive dyes in the extracellular solution may then diffuse into the perforated red blood cells and become entrapped upon restoration of physiological temperature and osmolarity. Because the membranes contain various analyte transporters, intracellular analyte levels rapidly equilibrate to those of the extracellular solution. A fluorescent dye has been loaded inside of red blood cells using a preswelling technique. Alterations in preparation parameters have been shown to affect characteristics of the resulting dye-loaded red blood cells (e.g., intensity of fluorescence).

  16. Electro- and photoluminescence imaging as fast screening technique of the layer uniformity and device degradation in planar perovskite solar cells

    Science.gov (United States)

    Soufiani, Arman Mahboubi; Tayebjee, Murad J. Y.; Meyer, Steffen; Ho-Baillie, Anita; Sung Yun, Jae; MacQueen, Rowan W.; Spiccia, Leone; Green, Martin A.; Hameiri, Ziv

    2016-07-01

    In this study, we provide insights into planar structure methylammonium lead triiodide (MAPbI3) perovskite solar cells (PSCs) using electroluminescence and photoluminescence imaging techniques. We demonstrate the strength of these techniques in screening relatively large area PSCs, correlating the solar cell electrical parameters to the images and visualizing the features which contribute to the variation of the parameters extracted from current density-voltage characterizations. It is further used to investigate one of the major concerns about perovskite solar cells, their long term stability and aging. Upon storage under dark in dry glovebox condition for more than two months, the major parameter found to have deteriorated in electrical performance measurements was the fill factor; this was elucidated via electroluminescence image comparisons which revealed that the contacts' quality degrades. Interestingly, by deploying electroluminescence imaging, the significance of having a pin-hole free active layer is demonstrated. Pin-holes can grow over time and can cause degradation of the active layer surrounding them.

  17. Robust low frequency current ripple elimination algorithm for grid-connected fuel cell systems with power balancing technique

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong-Soo; Choe, Gyu-Yeong; Lee, Byoung-Kuk [School of Information and Communication Engineering, Sungkyunkwan University, 300 Cheoncheon-dong, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Kang, Hyun-Soo [R and D Center, Advanced Drive Technology (ADT) Company, 689-26 Geumjeong-dong, Gunpo-si, Gyeonggi-do 435-862 (Korea, Republic of)

    2011-05-15

    The low frequency current ripple in grid-connected fuel cell systems is generated from dc-ac inverter operation, which generates 60 Hz fundamental component, and gives harmful effects on fuel cell stack itself, such as making cathode surface responses slower, causing an increase of more than 10% in the fuel consumption, creating oxygen starvation, causing a reduction in the operating lifetime, and incurring a nuisance tripping such as overload situation. With these reasons, low frequency current ripple makes fuel cell system unstable and lifetime of fuel cell stack itself short. This paper presents a fast and robust control algorithm to eliminate low frequency current ripple in grid-connected fuel cell systems. Compared with the conventional methods, in the proposed control algorithm, dc link voltage controller is shifted from dc-dc converter to dc-ac inverter, resulting that dc-ac inverter handles dc link voltage control and output current control simultaneously with help of power balancing technique. The results indicate that the proposed algorithm can not only completely eliminate current ripple but also significantly reduce the overshoot or undershoot during transient states without any extra hardware. The validity of the proposed algorithm is verified by computer simulations and also by experiments with a 1 kW laboratory prototype. (author)

  18. Effects of cell culture techniques on gene expression and cholesterol efflux in primary bovine mammary epithelial cells derived from milk and tissue.

    Science.gov (United States)

    Sorg, D; Potzel, A; Beck, M; Meyer, H H D; Viturro, E; Kliem, H

    2012-10-01

    Primary bovine mammary epithelial cells (pbMEC) are often used in cell culture to study metabolic and inflammatory processes in the udder of dairy cows. The most common source is udder tissue from biopsy or after slaughter. However, it is also possible to culture them from milk, which is non-invasive, repeatable and yields less contamination with fibroblasts. Generally, not much is known about the influence of cell origin and cell culture techniques such as cryopreservation on pbMEC functionality. Cells were extracted from milk and udder tissue to evaluate if milk-derived pbMEC are a suitable alternative to tissue-derived pbMEC and to test what influence cryopreservation has. The cells were cultivated for three passages and stored in liquid nitrogen. The relative gene expression of the five target genes kappa-casein, lingual antimicrobial peptide (LAP), lactoferrin, lysozyme (LYZ1) and the prolactin receptor normalised with keratin 8 showed a tendency to decrease in the tissue cultures, but not in the milk-derived cultures, suggesting a greater influence of the cultivation process on tissue-derived cells, freezing lowered expression levels in both cultures. Overall expression of LAP and LYZ1 tended to be higher in milk cells. Cholesterol efflux was measured to compare passages one to seven in milk-derived cells. Passage number did not alter the efflux rate (p ≤ 0.05). We showed for the first time that the extraction of pbMEC from milk can be a suitable alternative to tissue extraction.

  19. Multifrequency impedance measurement technique for wireless characterization of microbiological cell cultures

    Science.gov (United States)

    Wissenwasser, J.; Vellekoop, M. J.; Kapferer, W.; Lepperdinger, G.; Heer, R.

    2011-11-01

    An impedance measurement system with probe signal frequencies up to 50 kHz with AC-probe voltages below 30 mV rms was integrated for wireless and battery-free monitoring of microbiological cell cultures. The here presented modular design and the use of state-of-the-art components greatly eases adoptions to a wide range of biotechnological applications without the need of bulky LCR-meters or potentiostats. The device had a power consumption of less than 2.5 mA at a 3.3 V single power supply and worked trouble-free within the humid environment of a cell culture incubator. Measurements on lumped RC-elements showed an error of less than 1% for absolute values and less than 1° regarding the phase of the complex impedance. The performance of sensor devices with interdigitated electrode structures for the measurement of adherent cell cultures was tested in the presence of phosphate-buffered saline solution in the humid atmosphere of an incubator for biological cell cultures.

  20. Enzyme separation techniques for the study of growth of cells from layers of bovine dental pulp.

    Science.gov (United States)

    Miller, W A; Everett, M M; Freedman, J T; Feagans, W C; Cramer, J F

    1976-08-01

    Effects of the enzymes trypsin, papain, bromelains and ficin on bovine dental pulp tissue were studied. Minced or whole pulps were subjected to each enzyme at 17 degrees, 20 degrees and 37 degrees C for set time intervals, after which aliquots of supernatant fluid were removed for cell counts and viability tests. Pooled samples were subsequently cultured as monolayers in Eagle's MEM plus 10% calf serum. The dissociation characteristics were quite distinct for each enzyme, although quite similar between minced and whole pulp. A parallel histological study was made of the residual pulp tissue. Ficin was found to be the most suitable enzyme for future studies on the growth of isolated pulp cells from various layers of the bovine pulp, due to its even rate of cell removal, and the good initial viability and subsequent growth of the separated cells in monolayer culture. Further studies on ficin may show that it is more suitable for enzymatic separation of tissues generally than the more commonly used trypsin, a major advantage being its use in media containing Ca2+ and Mg2+.

  1. Photorespiration and temperature dependence of oxygen evolution in tomato plants monitored by open photoacoustic cell technique

    Science.gov (United States)

    Vargas-Luna, M.; Madueño, L.; Gutiérrez-Juárez, G.; Bernal-Alvarado, J.; Sosa, M.; González-Solís, J. L.; Sánchez-Rocha, S.; Olalde-Portugal, V.; Alvarado-Gil, J. J.; Campos, P.

    2003-01-01

    The open photoacoustic cell was used to monitor the evolution rate of oxygen from tomato leaves. Estimates of the relative amount of released oxygen in vivo and in situ conditions as influenced by ambient temperature are being presented. Photorespiration phenomenon is shown to dominate above a critical temperature. The evolution of this critical point is analyzed as a function of the environmental temperature.

  2. The design of a high power ultrasonic test cell using finite element modelling techniques.

    Science.gov (United States)

    Gachagan, A; Speirs, D; McNab, A

    2003-06-01

    This paper will describe the application of a finite element (FE) code to design a test cell, in which a single transducer is used to generate acoustic cavitation. The FE model comprises a 2-D slice through the centre of the test cell and was used to evaluate the generated pressure fields as a function of frequency. Importantly, the pressure fields predicted by FE modelling are used to indicate the position of pressure peaks, or 'hot-spots', and nulls enabling the systems design engineer to visualise both the potential cavitation areas, corresponding to the 'hot-spots', and areas of low acoustic pressure. Through this design process, a rectangular test cell was constructed from perspex for use with a 40 kHz Tonpilz transducer. A series of experimental measurements was conducted to evaluate the cavitation threshold as a function of temperature and viscosity/surface tension, for different fluid load media. The results indicate the potential of the FE design approach and assist the design engineer in understanding the influence of the fluid load medium on the cell's ability to produce a strong cavitation field.

  3. Developments in application of light and scanning electron microscopy techniques for cell wall degradation studies.

    NARCIS (Netherlands)

    Engels, F.M.

    1996-01-01

    The results of recent technological developments in light and scanning electron microscopy closely used for research on forage cell wall degradation in ruminants, are reviewed. The indigestibility of forages by rumen microorganisms used to be ascribed mainly to an overall presence of lignin in the p

  4. Multifrequency impedance measurement technique for wireless characterization of microbiological cell cultures.

    Science.gov (United States)

    Wissenwasser, J; Vellekoop, M J; Kapferer, W; Lepperdinger, G; Heer, R

    2011-11-01

    An impedance measurement system with probe signal frequencies up to 50 kHz with AC-probe voltages below 30 mV rms was integrated for wireless and battery-free monitoring of microbiological cell cultures. The here presented modular design and the use of state-of-the-art components greatly eases adoptions to a wide range of biotechnological applications without the need of bulky LCR-meters or potentiostats. The device had a power consumption of less than 2.5 mA at a 3.3 V single power supply and worked trouble-free within the humid environment of a cell culture incubator. Measurements on lumped RC-elements showed an error of less than 1% for absolute values and less than 1° regarding the phase of the complex impedance. The performance of sensor devices with interdigitated electrode structures for the measurement of adherent cell cultures was tested in the presence of phosphate-buffered saline solution in the humid atmosphere of an incubator for biological cell cultures.

  5. Utility of slot-blot-ELISA as a new, fast, and sensitive immunoassay for detection of carcinoembryonic antigen in the urine samples of patients with various gastrointestinal malignancies.

    Science.gov (United States)

    El-Masry, Samir; El-Sayed, Ibrahim H; Lotfy, Mahmoud; Mahmoud, Lamiaa; El-Naggar, Mohamed

    2007-01-01

    Carcinoembryonic antigen (CEA) is the most widely used clinical tumor marker. CEA immunoassay has found acceptance as a diagnostic adjunct in clinical diagnosis of gastrointestinal tumors (GIT). Several immunoassays have been established for detection of CEA in plasma, serum, tissue, feces, and urine of cancer patients using polyclonal or monoclonal antibodies raised against CEA. Some of these assays display both high sensitivity and specificity for the detection of CEA. However, these assays require special and highly expensive equipment and the procedures require long periods for their completion. In the present study, we established a Slot-Blot Enzyme Linked Immunosorbent Assay (SB-ELISA), based on anti-CEA monoclonal antibody (CEA-mAb), as a new, simple, fast, cheap, and non-invasive immunodiagnostic technique for detection of CEA in the urine of GIT patients. Urine and serum samples were collected from 248 GIT patients (58 with pancreatic cancer, 20 with hepatoma, 23 with ampullary carcinoma, 15 with hilar cholangiocarcinoma, 28 with gastric cancer, 14 with esophageal cancer, and 90 with colorectal cancer). Moreover, urine and serum samples were collected from 50 healthy individuals to serve as negative controls. The traditional ELISA technique was used for determination of CEA in the sera of GIT patients using anti-CEA monoclonal antibody. A comparison between the results of both techniques (ELISA and SB-ELISA) was carried out. The traditional ELISA detected CEA in the sera of 154 out of 248 GIT patients with a sensitivity of 59.8%, 51.7% positive predictive value (PPV) and 75.37% negative predictive value (NPV). In addition, it identified 15 false positive cases out of 50 healthy individuals with a specificity of 70%. The urinary CEA was identified by a Western blotting technique and CEA-mAb at a molecular mass of 180 Kda. The developed SB-ELISA showed higher sensitivity, specificity, PPV, and NPV (70.1%, 78%, 62.4%, and 82.13%, respectively) for detection

  6. Dual gratings for enhanced light trapping in thin-film solar cells by a layer-transfer technique.

    Science.gov (United States)

    Schuster, Christian S; Kowalczewski, Piotr; Martins, Emiliano R; Patrini, Maddalena; Scullion, Mark G; Liscidini, Marco; Lewis, Liam; Reardon, Christopher; Andreani, Lucio C; Krauss, Thomas F

    2013-05-01

    Thin film solar cells benefit significantly from the enhanced light trapping offered by photonic nanostructures. The thin film is typically patterned on one side only due to technological constraints. The ability to independently pattern both sides of the thin film increases the degrees of freedom available to the designer, as different functions can be combined, such as the reduction of surface reflection and the excitation of quasiguided modes for enhanced light absorption. Here, we demonstrate a technique based on simple layer transfer that allows us to independently pattern both sides of the thin film leading to enhanced light trapping. We used a 400 nm thin film of amorphous hydrogenated silicon and two simple 2D gratings for this proof-of-principle demonstration. Since the technique imposes no restrictions on the design parameters, any type of structure can be made.

  7. Microscopic observation of carrier-transport dynamics in quantum-structure solar cells using a time-of-flight technique

    Energy Technology Data Exchange (ETDEWEB)

    Toprasertpong, Kasidit; Fujii, Hiromasa; Sugiyama, Masakazu; Nakano, Yoshiaki [School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032 (Japan); Kasamatsu, Naofumi; Kada, Tomoyuki; Asahi, Shigeo; Kita, Takashi [Graduate School of Engineering, Kobe University, Nada-ku, Kobe 657-8501 (Japan); Wang, Yunpeng; Watanabe, Kentaroh [Research Center for Advanced Science and Technology, The University of Tokyo, Meguro-ku, Tokyo 153-8904 (Japan)

    2015-07-27

    In this study, we propose a carrier time-of-flight technique to evaluate the carrier transport time across a quantum structure in an active region of solar cells. By observing the time-resolved photoluminescence signal with a quantum-well probe inserted under the quantum structure at forward bias, the carrier transport time can be efficiently determined at room temperature. The averaged drift velocity shows linear dependence on the internal field, allowing us to estimate the quantum structure as a quasi-bulk material with low effective mobility containing the information of carrier dynamics. We show that this direct and real-time observation is more sensitive to carrier transport than other conventional techniques, providing better insights into microscopic carrier transport dynamics to overcome a device design difficulty.

  8. Comparison of Diagnostic Value of Antigen B and Protoscoleces Antigen in Diagnosis of Hydatid Cyst by Blotting Method

    Directory of Open Access Journals (Sweden)

    F. Oreizi

    2006-01-01

    Full Text Available Introduction & Objective : Hydatidosis, a disease caused by the cestod helminth echinococcus granulosus, is one of the most important parasitic zoonosis in man and a variety of animals. Sensitive and reliable serologic methods are necessary to confirm the diagnosis. In this study, Ag B and Psc Ag were purified as two specific parasitic antigens and evaluated by Dot blotting used on the serum of hydatidosis patients and control group in order to identify the most sensitive and specific subunits.Materials and Methods: In an analytic and comparative study, serum samples collected from 22 patients under operation of hydatid cyst. As a control group, 4 patients with acute toxoplasmosis, 4 patients with leishmaniasis, 4 patients infected by non-hydatid cestods(Tenia saginata and H.nana and 4 normal subjects were included in this investigation. Infected sheep’s liver and lung were used for the preparation of antigen. Cyst fluid containing protoscoleces was extracted and then partially purified with a protein A column. AgB and Psc Ags were interacted with hydatid and control sera, with Dot blot method and sensitivity and specificity of these antigens were evaluated. Results: Sensitivity and specificity were estimated 95.9% and 81% respectively, for AgB and 100% and 63% respectively, for Psc Ag in Dot blot Method. Conclusion: Evaluation of sensitivity and specificity of AgB and Psc Ag using Dot blotting revealed that AgB has high value for diagnosis of hydatidosis. and presumably can help physicians to diagnose hydatid cyst easier than other routine tests.

  9. Differentiation of Enterococcus faecium from Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus strains by PCR and dot-blot hybridisation.

    Science.gov (United States)

    Langa, S; Fernández, A; Martín, R; Reviriego, C; Marín, M L; Fernández, L; Rodríguez, J M

    2003-12-01

    Variations in length and sequence of the 16S/23S spacer region of Enterococcus faecium provided the basis for development of simple PCR and dot-blot hybridisation assays that enabled the differentiation of potentially probiotic Enterococcus faecium strains from Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. Such assays may be useful for differentiation of yoghurt starter cultures and enterococcal strains when they are simultaneously present in probiotic food products.

  10. Development of PCR/dot blot assay for specific detection and differentiation of taeniid cestode eggs in canids.

    Science.gov (United States)

    Armua-Fernandez, Maria Teresa; Nonaka, Nariaki; Sakurai, Tatsuya; Nakamura, Seita; Gottstein, Bruno; Deplazes, Peter; Phiri, Isaac G K; Katakura, Ken; Oku, Yuzaburo

    2011-01-01

    We report the development of a colourimetric PCR/dot blot assay targeting the mitochondrial gene NADH dehydrogenase subunit 1 (nad1) for differential diagnosis of taeniid eggs. Partial sequences of the cestode nad1 gene were aligned and new primers were designed based on conserved regions. Species-specific oligonucleotide probes (S-SONP) for canine taeniid cestodes were then designed manually based on the variable region between the conserved primers. Specifically, S-SONP were designed for the Taenia crassiceps, T. hydatigena, T. multiceps, T. ovis, T. taeniaeformis, Echinococcus granulosus (genotype 1), E. multilocularis and E. vogeli. Each probe showed high specificity as no cross-hybridisation with any amplified nad1 fragment was observed. We evaluated the assay using 49 taeniid egg-positive samples collected from dogs in Zambia. DNA from 5 to 10 eggs was extracted in each sample. Using the PCR/dot blot assay, the probes successfully detected PCR products from T. hydatigena in 42 samples, T. multiceps in 3 samples, and both species (mixed infection) in the remaining 4 samples. The results indicate that the PCR/dot blot assay is a reliable alternative for differential diagnosis of taeniid eggs in faecal samples.

  11. Discarded cell phone lithium ion batteries state of health quick method analysis by galvanostatic intermittent titration technique (GITT concept

    Directory of Open Access Journals (Sweden)

    Paulo Rogério Catarini

    2009-03-01

    Full Text Available The state of health (SOH is a important evaluation parameter to rechargeable batteries, because determine its cycle life and help on electric devices supplied by batteries maintenance. In this work the lithium ion discards cell phones batteries state of health and apparent diffusion coefficient (Dap were measured and correlated which purpose is diminish the batteries analyze time. The apparent diffusion coefficient is a ionic diffusion coefficient modification from GITT technique. The SOH and Dap correlation is well behaved, disclosing a cubic dependency. The time analyze was reduced by more than 1 h.

  12. Toward high efficiency ultra-thin CIGSe based solar cells using light management techniques

    Science.gov (United States)

    Naghavi, Negar; Jehl, Zacharie; Donsanti, Frederique; Guillemoles, Jean-François; Gérard, Isabelle; Bouttemy, Muriel; Etcheberry, Arnaud; Pelouard, Jean-Luc; Collin, Stéphane; Colin, Clément; Péré-Laperne, Nicolas; Dahan, Nir; Greffet, Jean-Jacques; Morel, Boris; Djebbour, Zakaria; Darga, Arouna; Mencaraglia, Denis; Voorwinden, Georg; Dimmler, Bernhard; Powalla, Micheal; Lincot, Daniel

    2012-02-01

    This study addresses the potential of different approaches to improve the generated current density in ultrathin Cu(In,Ga)Se2 (CIGSe) based solar cells down to 0.1 μm. Advanced photon management, involving both absorption enhancement and reflection reduction in the absorber, is studied. In this contribution, the three main approaches used are: - The reduction of the CIGSe thickness by chemical etching which combines thickness reduction and smoothing effect on the absorber. - Optical management by front contact engineering and by the replacement of the back contact by the "lift-off" of CIGSe layer from the Mo layer and the deposition of a new reflective back contact. - Application of plasmonic structures to CIGSe solar cells enabling light confinement at the subwavelength scale.

  13. Epitaxial thin film GaAs solar cells using OM-CVD techniques. [Organometallics

    Science.gov (United States)

    Stirn, R. J.; Wang, K. L.; Yeh, Y. C. M.

    1981-01-01

    A new approach has been initiated at JPL to fabricate thin-film, high efficiency GaAs solar cells on low-cost, single-crystal Si substrates having a thin CVD interlayer of Ge to minimize the lattice and thermal expansion mismatch. For initial experiments, n(+)/p GaAs cells were grown by OM-CVD on single-crystal GaAs and Ge wafers. Details of the growths and performance results will be presented. Subsequently, a combined epitaxial structure of OM-CVD GaAs on a strongly adherent Ge interlayer on (100) Si was grown. This is the first report of the successful growth of this composite structure. Low module costs projected by JPL SAMICS methodology calculations and the potential for 400-600W/kg space solar arrays will be discussed.

  14. Photoactive titania float for disinfection of water; evaluation of cell damage by bioanalytical techniques.

    Science.gov (United States)

    Shwetharani, R; Jyothi, M S; Laveena, P D; Geetha Balakrishna, R

    2014-01-01

    A photoactive float was fabricated with the modified titania to cause a feasible disinfection of water, contaminated with E. coli. The commercially available titania was doped with neodymium by pulverization technique to enhance its activity in sunlight and a multiapproach technique was used to evaluate the extended efficiency of the doped sample. X-ray diffraction patterns depicted the retention of anatase phase on doping and the existence of neodymium was confirmed by the energy dispersive atomic X-ray analysis and the X-ray photoelectron spectroscopy. Transmission electron microscopy and Bruner-Emmett-Teller analysis depicted a marginal increase in the particle size and a decrease in the surface area, respectively. Doping induces semiconductor behavior with lower band energy that could respond to visible light and exhibit better disinfection activity. The "f" and "d" transitions of the lanthanide in doped sample caused new electronic behavior of trapping/detrapping effect together with bandgap narrowing. The amount of malondialdehyde, protein, DNA and RNA released on destruction of E. coli was observed to be 0.915 × 10(-3) μg mL(-1), 859.912 μg mL(-1), 20.173 μg mL(-1) and 1146.073 μg mL(-1), respectively. The above analytical methods along with standard plate count method substantiated the enhanced disinfection efficiency of the doped sample in sunlight.

  15. Probing Ternary Solvent Effect in High V(oc) Polymer Solar Cells Using Advanced AFM Techniques.

    Science.gov (United States)

    Li, Chao; Ding, Yi; Soliman, Mikhael; Lorenzo, Josie; Dhasmana, Nitesh; Chantharasupawong, Panit; Ievlev, Anton V; Gesquiere, Andre J; Tetard, Laurene; Thomas, Jayan

    2016-02-01

    This work describes a simple method to develop a high V(oc) low band gap PSCs. In addition, two new atomic force microscopy (AFM)-based nanoscale characterization techniques to study the surface morphology and physical properties of the structured active layer are introduced. With the help of ternary solvent processing of the active layer and C60 buffer layer, a bulk heterojunction PSC with V(oc) more than 0.9 V and conversion efficiency 7.5% is developed. In order to understand the fundamental properties of the materials ruling the performance of the PSCs tested, AFM-based nanoscale characterization techniques including Pulsed-Force-Mode AFM (PFM-AFM) and Mode-Synthesizing AFM (MSAFM) are introduced. Interestingly, MSAFM exhibits high sensitivity for direct visualization of the donor-acceptor phases in the active layer of the PSCs. Finally, conductive-AFM (cAFM) studies reveal local variations in conductivity in the donor and acceptor phases as well as a significant increase in photocurrent in the PTB7:ICBA sample obtained with the ternary solvent processing.

  16. Novel Surface Passivation Technique for Low-Temperature Solution-Processed Perovskite PV Cells.

    Science.gov (United States)

    Tripathi, Neeti; Shirai, Yasuhiro; Yanagida, Masatoshi; Karen, Akiya; Miyano, Kenjiro

    2016-02-01

    Low-temperature solution-processed perovskite solar cells are attracting immense interest due to their ease of fabrication and potential for mass production on flexible substrates. However, the unfavorable surface properties of planar substrates often lead to large variations in perovskite crystal size and weak charge extractions at interfaces, resulting in inferior performance. Here, we report the improved performance, reproducibility, and high stability of "p-i-n" planar heterojunction perovskite solar cells. The key fabrication process is the addition of the amine-polymer poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN-P1) to a simple spin-coating process. The PFN-P1 works as a surfactant and helps promote uniform crystallization. As a result, perovskite films with PFN-P1 have a uniform distribution of grain sizes and improved open circuit voltage. Devices with PFN-P1 showed the best efficiency (13.2%), with a small standard deviation (0.40), out of 60 cells. Moreover, ∼90% of the initial efficiency was retained over more than 6 months. Additionally, devices fabricated from PFN-P1 mixed perovskite films showed higher stability under continuous operation at maximum power point over 150 h. Our results show that this approach is simple and effective for improving device performance, reproducibility, and stability by modifying perovskite properties with PFN-P1. Because of the simplicity of the fabrication process and reliable performance increase, this approach marks important progress in low-temperature solution-processed perovskite solar cells.

  17. Utilization of a cell separation technique to evaluate patients with a positive direct antiglobulin test.

    Science.gov (United States)

    Wallas, C H; Tanley, P C; Gorrell, L P

    1982-01-01

    Density distribution curves of red blood cells (RBC) from patients with a positive direct antiglobulin test (DAT) were compared to a standardized curve constructed from cell column measurements of centrifuged microcapillary tubes filled with RBC and phthalate ester mixtures encompassing a specific gravity range of 1.078 to 1.114. Shortened survival resulted in a loss of older RBC and a shift of the curve to the right over the high specific gravity ester range. Reticulocytosis resulted in a downward shift of the curve over the low specific gravity range. In patients with a positive DAT due to an autoantibody or drug, the density distribution curve was either normal or demonstrated evidence of shortened RBC survival. In patients with a positive DAT due to an alloantibody, however, evidence of shortened survival was not seen. The distribution of antibody on young and old RBC harvested from the appropriate microcapillary tubes depended upon the etiology of that antibody. In patients with a positive DAT due to to an alloantibody or drug, both the young and old RBC gave an equally reactive DAT, while in patients with a positive DAT due to an alloantibody the young cells were weakly reactive or nonreactive and the older cells were more strongly reactive. When used together, the position of the density distribution curve and the pattern of distribution of antibody coating on young and old RBC provide important diagnostic information about the etiology and clinical status in a patient with a positive DAT and allow for the recognition of an alloantibody and autoantibody when both are present in the same patient.

  18. “Humanized” Stem Cell Culture Techniques: The Animal Serum Controversy

    OpenAIRE

    Chandana Tekkatte; Gency Ponrose Gunasingh; Cherian, K M; Kavitha Sankaranarayanan

    2011-01-01

    Cellular therapy is reaching a pinnacle with an understanding of the potential of human mesenchymal stem cells (hMSCs) to regenerate damaged tissue in the body. The limited numbers of these hMSCs in currently identified sources, like bone marrow, adipose tissue, and so forth, bring forth the need for their in vitro culture/expansion. However, the extensive usage of supplements containing xenogeneic components in the expansion-media might pose a risk to the post-transplantation safety of ...

  19. Characterization of new materials in chromatography and fuel cell development by modern NMR techniques

    OpenAIRE

    Schauff, Siri

    2007-01-01

    Phosphonic acids for high temperature fuel cell membrane materials were investigated with respect to proton mobility and transport applying solid-state NMR spectroscopy. Water uptake and its effects on anhydride formation were studied on samples that were equilibrated with saturated salt solutions. For polyvinylphosphonic acid reversible anhydride formation was found. Variable temperature 1H MAS NMR spectroscopy of three different phosphonic acids revealed single proton sites, and 1H chemical...

  20. Cell adhesion to plasma electrolytic oxidation (PEO) titania coatings, assessed using a centrifuging technique.

    Science.gov (United States)

    Robinson, H J; Markaki, A E; Collier, C A; Clyne, T W

    2011-11-01

    The adhesion of bovine chondrocytes and human osteoblasts to three titania-based coatings, formed by plasma electrolytic oxidation (PEO), was compared to that on uncoated Ti-6Al-4V substrates, and some comparisons were also made with plasma sprayed hydroxyapatite (HA) coatings. This was done using a centrifuge, with accelerations of up to 160,000 g, so as to induce buoyancy forces that created normal or shear stresses at the interface. It is shown that, on all surfaces, it was easier to remove cells under normal loading than under shear loading. Cell adhesion to the PEO coatings was stronger than that on Ti-6Al-4V and similar to that on HA. Cell proliferation rates were relatively high on one of the PEO coatings, which was virtually free of aluminium, but low on the other two, which contained significant levels of aluminium. It is concluded that the Al-free PEO coating offers promise for application to prosthetic implants.

  1. Scheduling and sequencing in four machines robotic cell: Application of genetic algorithm and enumeration techniques

    Directory of Open Access Journals (Sweden)

    M.M.S. Abdulkader

    2013-09-01

    Full Text Available The introduction of robotic cells to manufacturing systems improved the efficiency, productivity and reliability of the system. The main objective of the scheduling problem of multi-item multi-machine robotic cells is the identification of the optimum robot cycle/s and jobs sequencing for certain processing conditions which yield the higher possible production rate. The objective of this work is to solve the scheduling problem in four-machine blocking robotic cells producing identical and different part types while minimizing the cycle time. A genetic algorithm is developed to find the parts sequence that minimizes the robot-moves cycle time for each robot cycle. The results showed that the developed genetic algorithm yields competitive results compared to the results of the full enumeration of all possible parts sequences. The results show also that the ratio between the average processing time of all parts and the robot travel time determines the cycle having the optimal robot-moves.

  2. Thermoforming techniques for manufacturing porous scaffolds for application in 3D cell cultivation.

    Science.gov (United States)

    Borowiec, Justyna; Hampl, Jörg; Gebinoga, Michael; Elsarnagawy, Tarek; Elnakady, Yasser A; Fouad, Hassan; Almajhadi, Fahd; Fernekorn, Uta; Weise, Frank; Singh, Sukhdeep; Elsarnagawy, Dief; Schober, Andreas

    2015-04-01

    Within the scientific community, there is an increasing demand to apply advanced cell cultivation substrates with increased physiological functionalities for studying spatially defined cellular interactions. Porous polymeric scaffolds are utilized for mimicking an organ-like structure or engineering complex tissues and have become a key element for three-dimensional (3D) cell cultivation in the meantime. As a consequence, efficient 3D scaffold fabrication methods play an important role in modern biotechnology. Here, we present a novel thermoforming procedure for manufacturing porous 3D scaffolds from permeable materials. We address the issue of precise thermoforming of porous polymer foils by using multilayer polymer thermoforming technology. This technology offers a new method for structuring porous polymer foils that are otherwise available for non-porous polymers only. We successfully manufactured 3D scaffolds from solvent casted and phase separated polylactic acid (PLA) foils and investigated their biocompatibility and basic cellular performance. The HepG2 cell culture in PLA scaffold has shown enhanced albumin secretion rate in comparison to a previously reported polycarbonate based scaffold with similar geometry.

  3. Fabrication of Semi-Transparent Photovoltaic Cell by a Cost-Effective Technique

    Science.gov (United States)

    Nithyayini, K. N.; Ramasesha, Sheela K.

    2015-09-01

    Semi-transparent inorganic thin film PV cells have been fabricated using n-type (CdS) and p-type (CdTe) semiconductors. Large area devices which can be used as windows and skylights in buildings can be fabricated using cost effective solution processes. The device structure is Glass/TCO/CdTe/CdS/TCO. Chemically stable CdS and CdTe layers are deposited at temperatures 353 K to 373 K (80 °C to 100 °C) under controlled pH. The CdCl2 activation is carried out followed by air annealing. The p-n junction is formed by sintering the device at 673 K to 723 K (400 °C to 450 °C). The characterization of cells is carried out using XRD, SEM, AFM, and UV-Visible spectroscopy. The thickness of the cell is ~600 nm. The band gap values are 2.40 eV for CdS and 1.36 eV for CdTe with transmittance of about 70 pct in the visible region. Under 1.5 AM solar spectrum, V oc, and I sc of the initial device are 3.56e-01 V and 6.20e-04 A, respectively.

  4. Load-balancing techniques for a parallel electromagnetic particle-in-cell code

    Energy Technology Data Exchange (ETDEWEB)

    PLIMPTON,STEVEN J.; SEIDEL,DAVID B.; PASIK,MICHAEL F.; COATS,REBECCA S.

    2000-01-01

    QUICKSILVER is a 3-d electromagnetic particle-in-cell simulation code developed and used at Sandia to model relativistic charged particle transport. It models the time-response of electromagnetic fields and low-density-plasmas in a self-consistent manner: the fields push the plasma particles and the plasma current modifies the fields. Through an LDRD project a new parallel version of QUICKSILVER was created to enable large-scale plasma simulations to be run on massively-parallel distributed-memory supercomputers with thousands of processors, such as the Intel Tflops and DEC CPlant machines at Sandia. The new parallel code implements nearly all the features of the original serial QUICKSILVER and can be run on any platform which supports the message-passing interface (MPI) standard as well as on single-processor workstations. This report describes basic strategies useful for parallelizing and load-balancing particle-in-cell codes, outlines the parallel algorithms used in this implementation, and provides a summary of the modifications made to QUICKSILVER. It also highlights a series of benchmark simulations which have been run with the new code that illustrate its performance and parallel efficiency. These calculations have up to a billion grid cells and particles and were run on thousands of processors. This report also serves as a user manual for people wishing to run parallel QUICKSILVER.

  5. Solid-state ZnS quantum dot-sensitized solar cell fabricated by the Dip-SILAR technique

    Science.gov (United States)

    Mehrabian, M.; Mirabbaszadeh, K.; Afarideh, H.

    2014-08-01

    Solid-state quantum dot sensitized solar cells (QDSSCs) were fabricated with zinc sulfide quantum dots (ZnS QDs), which served as the light absorber and the recombination blocking layer simultaneously. ZnS QDs were prepared successfully by a novel successive ionic layer adsorption and reaction technique based on dip-coating (Dip-SILAR). The dependences of the photovoltaic parameters on the number of SILAR cycles (n) were investigated. The cell with n = 6 (particle average size ˜9 nm) showed an energy conversion efficiency of 2.72% under the illumination of one sun (AM 1.5, 100 mW cm-2). Here we investigate also the cohesion between ZnS QDs and ZnO film to obtain a well-covering QD layer.

  6. Proteomic data analysis of glioma cancer stem-cell lines based on novel nonlinear dimensional data reduction techniques

    Science.gov (United States)

    Lespinats, Sylvain; Pinker-Domenig, Katja; Wengert, Georg; Houben, Ivo; Lobbes, Marc; Stadlbauer, Andreas; Meyer-Bäse, Anke

    2016-05-01

    Glioma-derived cancer stem cells (GSCs) are tumor-initiating cells and may be refractory to radiation and chemotherapy and thus have important implications for tumor biology and therapeutics. The analysis and interpretation of large proteomic data sets requires the development of new data mining and visualization approaches. Traditional techniques are insufficient to interpret and visualize these resulting experimental data. The emphasis of this paper lies in the application of novel approaches for the visualization, clustering and projection representation to unveil hidden data structures relevant for the accurate interpretation of biological experiments. These qualitative and quantitative methods are applied to the proteomic analysis of data sets derived from the GSCs. The achieved clustering and visualization results provide a more detailed insight into the protein-level fold changes and putative upstream regulators for the GSCs. However the extracted molecular information is insufficient in classifying GSCs and paving the pathway to an improved therapeutics of the heterogeneous glioma.

  7. A quantitative method for measurement of HL-60 cell apoptosis based on diffraction imaging flow cytometry technique.

    Science.gov (United States)

    Yang, Xu; Feng, Yuanming; Liu, Yahui; Zhang, Ning; Lin, Wang; Sa, Yu; Hu, Xin-Hua

    2014-07-01

    A quantitative method for measurement of apoptosis in HL-60 cells based on polarization diffraction imaging flow cytometry technique is presented in this paper. Through comparative study with existing methods and the analysis of diffraction images by a gray level co-occurrence matrix algorithm (GLCM), we found 4 GLCM parameters of contrast (CON), cluster shade (CLS), correlation (COR) and dissimilarity (DIS) exhibit high sensitivities as the apoptotic rates. It was further demonstrated that the CLS parameter correlates significantly (R(2) = 0.899) with the degree of nuclear fragmentation and other three parameters showed a very good correlations (R(2) ranges from 0.69 to 0.90). These results demonstrated that the new method has the capability for rapid and accurate extraction of morphological features to quantify cellular apoptosis without the need for cell staining.

  8. Development and experimental basis of local subretinal technique of xenogenic’s injection stem cells labelled by magnetic perticles

    Directory of Open Access Journals (Sweden)

    Yu. A. Belyy

    2014-01-01

    Full Text Available Purpose: is to develop a technique for local subretinal injection of xenogeneic stem cells labeled with magnetic particles and to prove experimentally its effectiveness.Material and methods: We used a line of stem cells HEK-293 GFP,labeled with magnetic particles. The study was made on 84 eyes of 42 chinchilla rabbits 6 months of age, the weight were from 2.5 to 3.5 kg. All right eyes were experimental (42 eyes and all left eyes (42 eyes were the control group. In the experimental group we used original complex of polymer elastic magnetic implant (PEMI with laser probe and fixed it to the sclera, then we made a median vitrectomy and injected HEK-293 GFP under the retina using a specially designed dispenser. In the control group PEMI was not fixed. We examined animals using biomicroscopy, ophthalmoscopy, ultrasound scanning, optical coherence tomography  OCT, computer tomography (CT, morphological study (cryohistological sections in 1, 3, 5, 7, 14 day and 1 month after surgery.Results: According the results of biomicroscopy in observation periods up to 3 days the vascular injection was visualized in the area operation. According the results of ophthalmoscopy and ultrasound scanning in 1 day the local retinal detachment was visualized in the area of local injection of the stem cells, which was not visualized in terms of further observations. CT helped us to confirm the local place of PEMI fixation. The morphological study results showed that cells were located in the subretinal space up to 14 days in the experimental group, and only up 3 days in the control group.Conclusion: The suggested surgical technique enables to control the injection of cells into the subretinal space, reduces the risk of tissue damage and exit cells in the vitreous space. The suggested methodology allows the fixing of the cellular material in the local place of the injection and enables to predict cells`s movement.

  9. Development and experimental basis of local subretinal technique of xenogenic’s injection stem cells labelled by magnetic perticles

    Directory of Open Access Journals (Sweden)

    Yu. A. Belyy

    2014-10-01

    Full Text Available Purpose: is to develop a technique for local subretinal injection of xenogeneic stem cells labeled with magnetic particles and to prove experimentally its effectiveness.Material and methods: We used a line of stem cells HEK-293 GFP,labeled with magnetic particles. The study was made on 84 eyes of 42 chinchilla rabbits 6 months of age, the weight were from 2.5 to 3.5 kg. All right eyes were experimental (42 eyes and all left eyes (42 eyes were the control group. In the experimental group we used original complex of polymer elastic magnetic implant (PEMI with laser probe and fixed it to the sclera, then we made a median vitrectomy and injected HEK-293 GFP under the retina using a specially designed dispenser. In the control group PEMI was not fixed. We examined animals using biomicroscopy, ophthalmoscopy, ultrasound scanning, optical coherence tomography  OCT, computer tomography (CT, morphological study (cryohistological sections in 1, 3, 5, 7, 14 day and 1 month after surgery.Results: According the results of biomicroscopy in observation periods up to 3 days the vascular injection was visualized in the area operation. According the results of ophthalmoscopy and ultrasound scanning in 1 day the local retinal detachment was visualized in the area of local injection of the stem cells, which was not visualized in terms of further observations. CT helped us to confirm the local place of PEMI fixation. The morphological study results showed that cells were located in the subretinal space up to 14 days in the experimental group, and only up 3 days in the control group.Conclusion: The suggested surgical technique enables to control the injection of cells into the subretinal space, reduces the risk of tissue damage and exit cells in the vitreous space. The suggested methodology allows the fixing of the cellular material in the local place of the injection and enables to predict cells`s movement.

  10. Investigation of Non-Vacuum Deposition Techniques in Fabrication of Chalcogenide-Based Solar Cell Absorbers

    KAUST Repository

    Alsaggaf, Ahmed

    2015-07-01

    The environmental challenges are increasing, and so is the need for renewable energy. For photovoltaic applications, thin film Cu(In,Ga)(S,Se)2 (CIGS) and CuIn(S,Se)2 (CIS) solar cells are attractive with conversion efficiencies of more than 20%. However, the high-efficiency cells are fabricated using vacuum technologies such as sputtering or thermal co-evaporation, which are very costly and unfeasible at industrial level. The fabrication involves the uses of highly toxic gases such as H2Se, adding complexity to the fabrication process. The work described here focused on non-vacuum deposition methods such as printing. Special attention has been given to printing designed in a moving Roll-to-Roll (R2R) fashion. The results show potential of such technology to replace the vacuum processes. Conversion efficiencies for such non-vacuum deposition of Cu(In,Ga)(S,Se)2 solar cells have exceeded 15% using hazardous chemicals such as hydrazine, which is unsuitable for industrial scale up. In an effort to simplify the process, non-toxic suspensions of Cu(In,Ga)S2 molecular-based precursors achieved efficiencies of ~7-15%. Attempts to further simplify the selenization step, deposition of CuIn(S,Se)2 particulate solutions without the Ga doping and non-toxic suspensions of Cu(In,Ga)Se2 quaternary precursors achieved efficiencies (~1-8%). The contribution of this research was to provide a new method to monitor printed structures through spectral-domain optical coherence tomography SD-OCT in a moving fashion simulating R2R process design at speeds up to 1.05 m/min. The research clarified morphological and compositional impacts of Nd:YAG laser heat-treatment on Cu(In,Ga)Se2 absorber layer to simplify the annealing step in non-vacuum environment compatible to R2R. Finally, the research further simplified development methods for CIGS solar cells based on suspensions of quaternary Cu(In,Ga)Se2 precursors and ternary CuInS2 precursors. The methods consisted of post deposition reactive

  11. Non-destructive Analysis of the Nuclei of Transgenic Living Cells Using Laser Tweezers and Near-infrared Raman Spectroscopic Technique

    Institute of Scientific and Technical Information of China (English)

    Wei Tang; Ronald J. Newton; Chang-An Xie; Yong-Qing Li; Nicki Whitley

    2005-01-01

    Transgenic cell lines of loblolly pine (Pinus taeda L.) were analyzed by a compact laser-tweezers-Raman-spectroscopy (LTRS) system in this investigation. A low power diode laser at 785 nm was used for both laser optical trapping of single transgenic cells and excitation for near-infrared Raman spectroscopy of the nuclei of synchronized cells, which were treated as single organic particles, at the S-phase of the cell cycle. Transgenic living cells with gfp and uidA genes were used as biological samples to test this LTRS technique. As expected, different Raman spectra were observed from the tested biological samples. This technique provides a high sensitivity and enables real-time spectroscopic measurements of transgenic cell lines. It could be a valuable tool for the study of the fundamental cell and molecular biological process by trapping single nucleus and by providing a wealth of molecular information about the nuclei of cells.

  12. Experimental analysis of pulsing techniques in a proton exchange fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Perez, Aquiles; Abtahi, Amir [Department of Ocean and Mechanical Engineering, Florida Atlantic University, Boca Raton, FL 33431 (United States); Zilouchian, Ali [Department of Electrical Engineering, Florida Atlantic University, Boca Raton, FL 33431 (United States)

    2011-02-01

    The purpose of this study is to investigate the impact of pulsing reactant flows on the performance of a PEMFC at low current density. This study considers a full range of pulsing flows and their effect in voltage over time. The factors evaluated were voltage, pressure, and flow rates of each reactant flow over time. A specific current density was set for the experiments. The experiments were performed at lower flow rates and temperatures of reactants than in standard operating conditions. The experiments used constant temperature of reactants as well as constant relative humidity. Comparison made between continuous flow and several sets of pulsing flows for hydrogen and air were developed. Pulsing of reactants opens an opportunity as a practical water management procedure. In addition, this technique helps extending performance range on PEMFC when a limited amount of reactants is supplied. The data collected was presented in graphical form. (author)

  13. Characterization of gastric cancer models from different cell lines orthotopically constructed using improved implantation techniques

    Institute of Scientific and Technical Information of China (English)

    Yan Li; Bo Li; Chun-Ping Xiang; Yu Zhang; Yuan-Yuan Li; Xiao-Ling Wu

    2012-01-01

    AIM: To develop orthotopic gastric cancer mouse models from different cell lines and characterize the tumor features to assist further in preclinical trials and clinical treatment strategies. METHODS: Human gastric cancer SGC-7901 and BGC- 823 cell suspensions were injected subcutaneously into nude mice to develop solid tumors, and tumor tissue pieces were then implanted under the serous coat of the stomach. An autopsy was performed on all animals of the SGC-7901 and BGC-823 models to observe the primary tumor growth and metastases using pathological and immunohistochemical methods. RESULTS: Both models showed large tumors in situ resulting in pressure and infiltration of the adjacent organs. The gastric cavity became smaller, along with stenosis of the cardia or pylorus. There were biological and statistical differences between the two models. The metastasis rate in involved organs (lymph nodes, kidney, spleen, testis) was significantly higher in the BGC-823 model compared to the SGC-7901 model (P < 0.05 or P < 0.01). The median survival of the BGC-823 model was shorter than that of SGC-7901 (23 d vs 84 d, P < 0.05). Histopathologically, the primary tumor and metastatic lesions of the two models showed obvious atypia and mucus in the cytoplasm. Compared with the SGC-7901 model, BGC-823 appeared more poorly differentiated (absence of adenoid structure), had a smaller volume, and richer capillary structure. Immunohistochemical staining revealed cytokeratin 20 and epithelial membrane antigen expression was positive in the SGC-7901 tumors, while negative in BGC-823 ones. CONCLUSION: Models using the SGC-7901 and BGC-823 cell lines were established which could function in gastric cancer research on carcinogenesis mechanism and drug discovery. The two models showed different tumor behavior and the latter was more malignant than the former.

  14. Migration and distribution of bone marrow stromal cells in injured spinal cord with different transplantation techniques

    Institute of Scientific and Technical Information of China (English)

    FAN Li; DU Fei; CHENG Bang-chang; PENG Hao; LIU Shi-qing

    2008-01-01

    To study the regularity of migration and distribution of bone marrow stromal cells (BMSCs)in iniured spinal cord with intradural space transplantation.Methods:Forty Wistar rats were randomly assigned into 4 groups. The spinal cord injury,model was prepared according to the modified Allen method. BMSCs were labeled by CM-Dil. And 5.0×10 6 cells were transplanted by different channels including intraventricular injection(Group A),injured spinal cord intrathecally injection(Group B),remote intrathecally injection at the L3-L4 level(Group C),and intravenous injection(Group D). Spinal cord was dissected at 24 hours,1,2,3 and 4 weeks after transplantation.Sections of 4 μm were cut on a cryostat and observed under fluorescence microscopy.Results:No fluorescence was observed 24 hours after transplantation in spinal cord injury parenchyma except Group B. One week later,BMSCs in Groups A and C began to migrate to the injured parenchyma;2-4 weeks later,BMSCs penetrated into the injured parenchyma except Group D.The number of BMSCS decreased at 3-4 weeks after transplantation. The number of cells in Group B decreased faster than that of Groups A and C.Conclusions:BMSCs transplanted through intraventricular injection,injured spinal cord intrathecally injection and remote intrathecal injection could migrate to the injured parenchyma of spinal cord effectively. The number of BMSCs migrated into injured spinal cord parenchyma is rare by intravenous injection.

  15. Comparative evaluation of techniques for the manufacturing of dendritic cell-based cancer vaccines.

    Science.gov (United States)

    Dohnal, Alexander Michael; Graffi, Sebastian; Witt, Volker; Eichstill, Christina; Wagner, Dagmar; Ul-Haq, Sidrah; Wimmer, Doris; Felzmann, Thomas

    2009-01-01

    Manufacturing procedures for cellular therapies are continuously improved with particular emphasis on product safety. We previously developed a dendritic cell (DC) cancer vaccine technology platform that uses clinical grade lipopolysaccharide (LPS) and interferon (IFN)-y for the maturation of monocyte derived DCs. DCs are frozen after 6 hrs exposure at a semi-mature stage (smDCs) retaining the capacity to secret interleukin (IL)-12 and thus support cytolytic T-cell responses, which is lost at full maturation. We compared closed systems for monocyte enrichment from leucocyte apheresis products from healthy individuals using plastic adherence, CD14 selection, or CD2/19 depletion with magnetic beads, or counter flow centrifugation (elutriation) using a clinical grade in comparison to a research grade culture medium for the following DC generation. We found that elutriation was superior compared to the other methods showing 36 +/- 4% recovery, which was approximately 5-fold higher as the most frequently used adherence protocol (8 +/- 1%), and a very good purity (92 +/- 5%) of smDCs. Immune phenotype and IL-12 secretion (adherence: 1.4 +/- 0.4; selection: 20 +/- 0.6; depletion: 1 +/-0.5; elutriation: 3.6 +/- 1.5 ng/ml) as well as the potency of all DCs to stimulate T cells in an allogeneic mixed leucocyte reaction did not show statistically significant differences. Research grade and clinical grade DC culture media were equally potent and freezing did not impair the functions of smDCs. Finally, we assessed the functional capacity of DC cancer vaccines manufactured for three patients using this optimized procedure thereby demonstrating the feasibility of manufacturing DC cancer vaccines that secret IL-12 (9.4 +/- 6.4 ng/ml). We conclude that significant steps were taken here towards clinical grade DC cancer vaccine manufacturing.

  16. Toward a systematic design theory for silicon solar cells using optimization techniques

    Science.gov (United States)

    Misiakos, K.; Lindholm, F. A.

    1986-01-01

    This work is a first detailed attempt to systematize the design of silicon solar cells. Design principles follow from three theorems. Although the results hold only under low injection conditions in base and emitter regions, they hold for arbitrary doping profiles and include the effects of drift fields, high/low junctions and heavy doping concentrations of donor or acceptor atoms. Several optimal designs are derived from the theorems, one of which involves a three-dimensional morphology in the emitter region. The theorems are derived from a nonlinear differential equation of the Riccati form, the dependent variable of which is a normalized recombination particle current.

  17. Total Pancreatectomy and Islet Cell Autotransplantation: Outcomes, Controversies and New Techniques

    Directory of Open Access Journals (Sweden)

    Michal Radomski

    2015-01-01

    Full Text Available Chronic pancreatitis is a challenging disease; the constellation of chronic abdominal pain and metabolic derangements present unique difficulties to the treating physician. Initial treatment revolves around lifestyle modification, pain control, and management of exocrine insufficiency. In refractory cases, total pancreatectomy with islet cell auto transplantation (TP-IAT is an option for patients with diffuse disease not amenable to subtotal pancreatectomy or a decompressive (drainage operation. This procedure aspires to alleviate pain and avoid surgically induced brittle diabetes, a morbid complication of total pancreatectomy alone. Herein, we review the indications, optimal timing, surgical outcomes and controversies for TP-IAT, focusing on recently published reports.

  18. Influence of different fluid resuscitation techniques on the number of myeloid-derived suppressor cells in rats.

    Science.gov (United States)

    Wang, Z J; Wang, H X; Li, L; Wang, L; Dou, H H

    2016-04-28

    We investigated the influence of different fluid resuscitation techniques on the number of myeloid-derived suppressor cells (MDSCs) in rats. Seventy-two healthy Sprague-Dawley rats were randomly divided into groups that received sham operation (Sham group), hypertonic saline (HRS group), lactated ringer's solution (LRS group), or crystalloid solution (LCRS group). Six rats from each group were sacrificed by cervical dislocation at 12, 24, and 48 h after resuscitation. The spleens were harvested under sterile conditions and spleen cell suspension was prepared. The number of MDSCs was detected using flow cytometry. The number of MDSCs in the Sham group did not differ significantly among the different time points. Compared with the Sham group, the number of MDSCs after the use of the different fluid resuscitation techniques increased to varying extents and the differences among the groups were significant. The number of MDSCs in the HRS group was much lower than that of the LRS and LCRS groups at both 24 and 48 h (P number of MDSCs in the HRS group was significantly lower than that of the LRS group (P < 0.05). The differences between the HRS and LCRS groups were not statistically significant. Shortly after hemorrhagic shock resuscitation, the immune function of rats was suppressed to a varying extent and was gradually restored over time. Resuscitation with HRS alleviated the immunosuppression at the early stage after shock.

  19. Technique for internal channelling of hydroentangled nonwoven scaffolds to enhance cell penetration.

    Science.gov (United States)

    Durham, Elaine R; Ingham, Eileen; Russell, Stephen J

    2013-08-01

    An important requirement in thick, high-porosity scaffolds is to maximise cellular penetration into the interior and avoid necrosis during culture in vitro. Hitherto, reproducible control of the pore structure in nonwoven scaffolds has proved challenging. A new, channelled scaffold manufacturing process is reported based on water jet entanglement of fibres (hydroentangling) around filamentous template to form a coherent scaffold that is subsequently removed. Longitudinally-oriented channels were introduced within the scaffold in controlled proximity using 220 µm diameter cylindrical templates. In this case study, channelled scaffolds composed of poly(l-lactic acid) were manufactured and evaluated in vitro. Environmental scanning electron microscope and µCT (X-ray microtomography) confirmed channel openings in the scaffold cross-section before and after cell culture with human dermal fibroblasts up to 14 weeks. Histology at week 11 indicated that the channels promoted cell penetration and distribution within the scaffold interior. At week 14, cellular matrix deposition was evident in the internal channel walls and the entrances remained unoccluded by cellular matrix suggesting that diffusion conduits for mass transfer of nutrient to the scaffold interior could be maintained.

  20. Fracture toughness of solid oxide fuel cell anode substrates determined by a double-torsion technique

    Science.gov (United States)

    Pećanac, G.; Wei, J.; Malzbender, J.

    2016-09-01

    Planar solid oxide fuel cell anode substrates are exposed to high mechanical loads during assembly, start-up, steady-state operation and thermal cycling. Hence, characterization of mechanical stability of anode substrates under different oxidation states and at relevant temperatures is essential to warrant a reliable operation of solid oxide fuel cells. As a basis for mechanical assessment of brittle supports, two most common anode substrate material variants, NiO-3YSZ and NiO-8YSZ, were analyzed in this study with respect to their fracture toughness at room temperature and at a typical stack operation temperature of 800 °C. The study considered both, oxidized and reduced materials' states, where also an outlook is given on the behavior of the re-oxidized state that might be induced by malfunctions of sealants or other functional components. Aiming at the improvement of material's production, different types of warm pressed and tape cast NiO-8YSZ substrates were characterized in oxidized and reduced states. Overall, the results confirmed superior fracture toughness of 3YSZ compared to 8YSZ based composites in the oxidized state, whereas in the reduced state 3YSZ based composites showed similar fracture toughness at room temperature, but a higher value at 800 °C compared to 8YSZ based composites. Complementary microstructural analysis aided the interpretation of mechanical characterization.

  1. Nonlinear imaging techniques for the observation of cell membrane perturbation due to pulsed electric field exposure

    Science.gov (United States)

    Moen, Erick K.; Beier, Hope T.; Thompson, Gary L.; Roth, Caleb C.; Ibey, Bennett L.

    2014-03-01

    Nonlinear optical probes, especially those involving second harmonic generation (SHG), have proven useful as sensors for near-instantaneous detection of alterations to orientation or energetics within a substance. This has been exploited to some success for observing conformational changes in proteins. SHG probes, therefore, hold promise for reporting rapid and minute changes in lipid membranes. In this report, one of these probes is employed in this regard, using nanosecond electric pulses (nsEPs) as a vehicle for instigating subtle membrane perturbations. The result provides a useful tool and methodology for the observation of minute membrane perturbation, while also providing meaningful information on the phenomenon of electropermeabilization due to nsEP. The SHG probe Di- 4-ANEPPDHQ is used in conjunction with a tuned optical setup to demonstrate nanoporation preferential to one hemisphere, or pole, of the cell given a single square shaped pulse. The results also confirm a correlation of pulse width to the amount of poration. Furthermore, the polarity of this event and the membrane physics of both hemispheres, the poles facing either electrode, were tested using bipolar pulses consisting of two pulses of opposite polarity. The experiment corroborates findings by other researchers that these types of pulses are less effective in causing repairable damage to the lipid membrane of cells.

  2. Detection of drug-dependent platelet antibodies by use of solid-phase red cell adherence techniques.

    Science.gov (United States)

    Leach, M F; Cooper, L K; Aubuchon, J P

    1995-01-01

    Many drugs have been reported to cause drug-dependent thrombocytopenia, either by the immune complex or by hapten mechanisms. Testing for the presence of these platelet antibodies has not been considered feasible for transfusion services because their presence was thought to be rare, and their detection involved complex and costly methods. We have developed a new technique for detection of these antibodies that can be performed without the need for specialized and expensive instrumentation. A solid-phase red cell adherence assay was used to detect drug-dependent platelet antibodies active by either the immune complex or the hapten mechanism. Three cases were evaluated for the presence of drug-dependent platelet antibodies. Two patients presented with thrombocytopenia that could not be attributed to other causes. The third case was evaluated for the presence of drug-dependent antibodies after poor responses to platelet transfusions. In these three cases, discontinuation of the implicated drugs, i.e., porcine heparin, quinine sulfate, amoxicillin, Bactrim, and albuterol, was followed by a correction of thrombocytopenia or improved platelet transfusion response within 72 hours. This test methodology and protocol has proven very useful in avoiding transfusions with little likelihood of benefit, and in identifying drugs interfering with platelet recovery or survival. Further investigations with this technique may expand our knowledge of the capability of this technique and of the observed frequency of drug-related immunologic platelet destruction.

  3. IDENTIFICATION OF CANINE VISCERAL LEISHMANIASIS IN A PREVIOUSLY UNAFFECTED AREA BY CONVENTIONAL DIAGNOSTIC TECHNIQUES AND CELL-BLOCK FIXATION

    Directory of Open Access Journals (Sweden)

    Tuanne Rotti ABRANTES

    2016-01-01

    Full Text Available After the report of a second case of canine visceral leishmaniasis (CVL in São Bento da Lagoa, Itaipuaçu, in the municipality of Maricá, Rio de Janeiro State, an epidemiological survey was carried out, through active search, totaling 145 dogs. Indirect immunofluorescence assay (IFA, enzyme-linked immunosorbent assay (ELISA, and rapid chromatographic immunoassay based on dual-path platform (DPP(r were used to perform the serological examinations. The parasitological diagnosis of cutaneous fragments was performed by parasitological culture, histopathology, and immunohistochemistry. In the serological assessment, 21 dogs were seropositive by IFA, 17 by ELISA, and 11 by DPP(r, with sensitivity of 66.7%, 66.7% and 50%, and specificity of 87.2%, 90.2% and 94%, respectively for each technique. The immunohistochemistry of bone marrow using the cell-block technique presented the best results, with six positive dogs found, three of which tested negative by the other parasitological techniques. Leishmania sp. was isolated by parasitological culture in three dogs. The detection of autochthonous Leishmania infantum in Itaipuaçu, and the high prevalence of seropositive dogs confirm the circulation of this parasite in the study area and alert for the risk of expansion in the State of Rio de Janeiro.

  4. Photo-irradiation paradigm: Mapping a remarkable facile technique used for advanced drug, gene and cell delivery.

    Science.gov (United States)

    Shaker, Mohamed A; Younes, Husam M

    2015-11-10

    Undoubtedly, the progression of photo-irradiation technique has provided a smart engineering tool for the state-of-the-art biomaterials that guide the biomedical and therapeutic domains for promoting the modern pharmaceutical industry. Many investigators had exploited such a potential technique to create/ameliorate numerous pharmaceutical carriers. These carriers show promising applications that vary from small drug to therapeutic protein delivery and from gene to living cell encapsulation design. Harmony between the properties of precisely engineered precursors and the formed network structure broadens the investigator's intellect for both brilliant creations and effective applications. As well, controlling photo-curing at the formulation level, through manipulating the absorption of light stimuli, photoinitiator system and photo-responsive precursor, facilitates the exploration of novel distinctive biomaterials. Discussion of utilizing different photo-curing procedures in designing/formulation of different pharmaceutical carriers is the main emphasis of this review. In addition, recent applications of these intelligent techniques in targeted, controlled, and sustained drug delivery with understanding of photo-irradiation concept and mechanism are illustrated.

  5. IDENTIFICATION OF CANINE VISCERAL LEISHMANIASIS IN A PREVIOUSLY UNAFFECTED AREA BY CONVENTIONAL DIAGNOSTIC TECHNIQUES AND CELL-BLOCK FIXATION

    Science.gov (United States)

    ABRANTES, Tuanne Rotti; MADEIRA, Maria de Fátima; da SILVA, Denise Amaro; PERIÉ, Carolina dos Santos F. S.; V. MENDES, Artur Augusto; MENEZES, Rodrigo Caldas; SILVA, Valmir Laurentino; FIGUEIREDO, Fabiano Borges

    2016-01-01

    After the report of a second case of canine visceral leishmaniasis (CVL) in São Bento da Lagoa, Itaipuaçu, in the municipality of Maricá, Rio de Janeiro State, an epidemiological survey was carried out, through active search, totaling 145 dogs. Indirect immunofluorescence assay (IFA), enzyme-linked immunosorbent assay (ELISA), and rapid chromatographic immunoassay based on dual-path platform (DPP(r)) were used to perform the serological examinations. The parasitological diagnosis of cutaneous fragments was performed by parasitological culture, histopathology, and immunohistochemistry. In the serological assessment, 21 dogs were seropositive by IFA, 17 by ELISA, and 11 by DPP(r), with sensitivity of 66.7%, 66.7% and 50%, and specificity of 87.2%, 90.2% and 94%, respectively for each technique. The immunohistochemistry of bone marrow using the cell-block technique presented the best results, with six positive dogs found, three of which tested negative by the other parasitological techniques. Leishmania sp. was isolated by parasitological culture in three dogs. The detection of autochthonous Leishmania infantum in Itaipuaçu, and the high prevalence of seropositive dogs confirm the circulation of this parasite in the study area and alert for the risk of expansion in the State of Rio de Janeiro. PMID:26910449

  6. A simplification of the enzyme-linked immunospot technique. Increased sensitivity for cells secreting IgG antibodies to Haemophilus influenzae type b capsular polysaccharide

    DEFF Research Database (Denmark)

    Barington, T; Sparholt, S; Juul, L

    1992-01-01

    A simplified enzyme-linked immunospot (ELISPOT) technique is described for the detection of cells secreting antibodies to tetanus toxoid (TT), diphtheria toxoid (DT) or Haemophilus influenzae type b capsular polysaccharide (PRP). By combining the cell suspension with the enzyme-linked secondary...... antibodies in one incubation, the second incubation and washing procedure could be omitted from the original technique. The simplified assay had the same sensitivity for anti-TT and anti-DT spot-forming cells as the ordinary ELISPOT assay. The IgG anti-PRP spots were, however, improved both in quality...... and in quantity (median: 40% more spots), while the detection of IgM and IgA anti-PRP spot-forming cells was the same in the two techniques. This simplified technique can probably also be used to save time in other antigen systems and should be considered when designing ELISPOT assays for the detection...

  7. Application of the MOS-C-V technique to determine impurity concentrations and surface parameters on the diffused face of silicon solar cells

    Science.gov (United States)

    Weinberg, I.

    1975-01-01

    The feasibility of using the MOS C-V technique to obtain information regarding impurity and surface state concentrations on the diffused face of silicon solar cells with Ta2O5 coatings is studied. Results indicate that the MOS C-V technique yields useful information concerning surface parameters which contribute to the high, efficiency limiting, surface recombination velocities on the n+ surface of silicon solar cells.

  8. Characterization of solar cells. New techniques with high spatial resolution; Entwicklung neuer Verfahren zur raeumlich hochaufloesenden Charakterisierung von Solarzellen

    Energy Technology Data Exchange (ETDEWEB)

    Schwalm, Michael

    2011-06-16

    Today's raising demand for energy relies to a degree of 85% on the consumption of fossil fuels. A change to regenerative forms of energy is an important and inevitable step in order to face the challenges of climate change and fading natural resources. Photovoltaic's (PV) plays a special role within the various forms of renewable energy since it converts sunlight, our most important and virtually endless energy source, directly into electricity. However, currently available PV-systems are still very expensive and, in combination with their relatively low performance, can hardly or cannot compete with conventional sources of energy from an economical point of view. One possibility to overcome this problem is the combination of highly efficient multi junction solar cells with cost-efficient concentrator optics that focus the incident sunlight to a small spot. The material system (GaIn)(NAs) is envisioned to play an important role in a future generation of multi junction solar cells for concentrator applications being a further development of existing device concepts. However, especially the carrier diffusion lengths in (GaIn)(NAs)-based solar cell layers are currently to low for the fabrication of highly efficient PV-structures. In this work, two novel techniques for the characterization of solar cells are developed and evaluated by experiments on test structures and numerical simulations. Both are based on the measurement of laser-induced currents. Spatially-resolved photocurrent spectroscopy (SRPS) allows a spatially-resolved determination of locally induced photocurrents at a fixed bias voltage while spatially-resolved IV-characteristics (SRIV) are measurements of local I-V-characteristics at a certain position. It is found that SRPS and SRIV allow for a reliable and meaningful characterization of solar cell prototypes with a high spatial resolution. Especially the local p-n-parameters of the sample become accessible. These are the short circuit current

  9. Structure of porous electrodes in polymer electrolyte membrane fuel cells: An optical reconstruction technique

    Science.gov (United States)

    Berejnov, Viatcheslav; Sinton, David; Djilali, Ned

    Computing flows and phase transport in porous media requires a physically representative geometric model. We present a simple method of digitizing the structure of fibrous porous media commonly used in polymer electrolyte membrane (PEM) fuel cells, the so-called gas diffusion layer (GDL). Employing an inverted microscope and image recognition software we process images of the GDL surface collected manually at different focal lengths with micrometer accuracy. Processing the series of images allows retrieval of local depths of the salient in-focus structural elements in each of the different images. These elements are then recombined into a depth-map representing the three-dimensional structure of the GDL surface. Superimposition of the in-focus portions of the structural elements distributed throughout the stack of images yields digitized data describing the geometry and structural attributes of the 3D surface of the GDL fibrous material.

  10. Power optimized variation aware dual-threshold SRAM cell design technique

    Directory of Open Access Journals (Sweden)

    Aminul Islam

    2011-02-01

    Full Text Available Aminul Islam1, Mohd Hasan21Department of Electronics and Communication Engineering, Birla Institute of Technology, Mesra, Ranchi, Jharkhand, India; 2Department of Electronics Engineering, Aligarh Muslim University, Aligarh, Uttar Pradesh, IndiaAbstract: Bulk complementary metal-oxide semiconductor (CMOS technology is facing enormous challenges at channel lengths below 45 nm, such as gate tunneling, device mismatch, random dopant fluctuations, and mobility degradation. Although multiple gate transistors and strained silicon devices overcome some of the bulk CMOS problems, it is sensible to look for revolutionary new materials and devices to replace silicon. It is obvious that future technology materials should exhibit higher mobility, better channel electrostatics, scalability, and robustness against process variations. Carbon nanotube-based technology is very promising because it has most of these desired features. There is a need to explore the potential of this emerging technology by designing circuits based on this technology and comparing their performance with that of existing bulk CMOS technology. In this paper, we propose a low-power variation-immune dual-threshold voltage carbon nanotube field effect transistor (CNFET-based seven-transistor (7T static random access memory (SRAM cell. The proposed CNFET-based 7T SRAM cell offers ~1.2× improvement in standby power, ~1.3× improvement in read delay, and ~1.1× improvement in write delay. It offers narrower spread in write access time (1.4× at optimum energy point [OEP] and 1.2× at 1 V. It features 56.3% improvement in static noise margin and 40% improvement in read static noise margin. All the simulation measurements are taken at proposed OEP decided by the optimum results obtained after extensive simulation on HSPICE (high-performance simulation program with integrated circuit emphasis environment.Keywords: carbon nanotube field effect transistor (CNFET, chirality vector, random dopant

  11. Clinical experience with a single field rotational total skin electron irradiation technique for cutaneous T-cell lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, C.R.; Shenouda, G.; Vuong, T.; Souhami, L.; Pla, M.; Podgorsak, E.B.; Pla, C. (McGill University, Montreal (Canada). Division of Radiation Oncology, Department of Oncology); Suissa, S. (McGill University, Montreal (Canada). Department of Epidemiology and Biostatics)

    1992-07-01

    Between October 1981 and December 1989, 44 patients with CTCL (cutaneous T-cell lymphoma) were treated with a single-field RTSEI (rotational total skin electron irradiation) technique developed in McGill University Radiation Oncology Department. Only 11/44 patients received no prior treatment (25%). Advanced (T[sub 3] or T[sub 4]) disease had 75% (33/44). Complete response was seen in 32/44 (73%) of patients (91% T[sub 2], 71% T[sub 3] and 58% T[sub 4]), only 27% (3/11) of patients with T[sub 2] and 14% (3/21) with T[sub 3] disease remain in continuous complete remission in the skin, after median intervals of 58 and 35 moths, resp. Median cause-specific survival for whole group is 43 months and survival at 5 years is 38%. Survival was much better for patients with T[sub 2] disease than for patients with T[sub 3] disease (relative risk 4.3; 95% CI 1.4-13.2) and patients with T[sub 4] disease (relative risk 3.1; 95% CI 0.8-12.1). The RTSEI technique used at McGill has depth-dose characteristics and photon contamination similar to other commonly used TSEI techniques. It is relatively simple and provides a homogenous dose distribution over entire skin surface in short treatment time. Results of treatment are similar to those obtained with other techniques. For T[sub 2] disease, TSEI is an effective treatment modality with a possibility of long-term tumor control. For more advanced disease, more aggressive treatment, which may include TSI, is necessary. (author). 27 refs.; 7 figs.; 3 tab.

  12. Novel tools, classic techniques: evolutionary studies using primate pluripotent stem cells.

    Science.gov (United States)

    Hrvoj-Mihic, Branka; Marchetto, Maria C N; Gage, Fred H; Semendeferi, Katerina; Muotri, Alysson R

    2014-06-15

    Recent applications of genomic tools on the analysis of alterations unique to our species coupled with a growing number of neuroanatomical studies across primates provide an unprecedented opportunity to compile different levels of human brain evolution into a complex whole. Applications of induced pluripotent stem cell (iPSC) technology, capable of reprogramming somatic tissue of different species and generating species-specific neuronal phenotypes, for the first time offer an opportunity to test specific evolutionary hypotheses in a field of inquiry that has been long plagued by the limited availability of research specimens. In this review, we will focus specifically on the experimental role of iPSC technology as applied to the analysis of neocortical pyramidal neurons. Pyramidal neurons emerge as particularly suitable for testing evolutionary scenarios, since they form the most common morphological class of neurons in the cortex, display morphological variations across different cortical areas and cortical layers that appear species-specific, and express unique molecular signatures. Human and nonhuman primate iPSC-derived neurons may represent a unique biological resource to elucidate the phenotypic differences between humans and other hominids. As the typical morphology of pyramidal neurons tends to be compromised in neurological disorders, application of iPSC technology to the analysis of pyramidal neurons could not only bring new insights into human adaptation but also offer opportunities to link biomedical research with studies of the origins of the human species.

  13. White light-emitting electrochemical cells based on the Langmuir-Blodgett technique.

    Science.gov (United States)

    Fernández-Hernández, Jesús M; De Cola, Luisa; Bolink, Henk J; Clemente-León, Miguel; Coronado, Eugenio; Forment-Aliaga, Alicia; López-Muñoz, Angel; Repetto, Diego

    2014-11-25

    Light-emitting electrochemical cells (LECs) showing a white emission have been prepared with Langmuir-Blodgett (LB) films of the metallosurfactant bis[2-(2,4-difluorophenyl)pyridine][2-(1-hexadecyl-1H-1,2,3-triazol-4-yl)pyridine]iridium(III) chloride (1), which work with an air-stable Al electrode. They were prepared by depositing a LB film of 1 on top of a layer of poly(N,N'-diphenyl-N,N'-bis(4-hexylphenyl)-[1,1'-biphenyl]-4,4'-diamine (pTPD) spin-coated on indium tin oxide (ITO). The white color of the electroluminescence of the device contrasts with the blue color of the photoluminescence of 1 in solution and within the LB films. Furthermore, the crystal structure of 1 is reported together with the preparation and characterization of the Langmuir monolayers (π-A compression isotherms and Brewster angle microscopy (BAM)) and LB films of 1 (IR, UV-vis and emission spectroscopy, X-ray photoelectron spectroscopy (XPS), specular X-ray reflectivity (SXR), and atomic force microscopy (AFM)).

  14. Glutathione Transferase GSTπ In Breast Tumors Evaluated By Three Techniques

    Directory of Open Access Journals (Sweden)

    Rafael Molina

    1993-01-01

    Full Text Available The glutathione transferases are involved in intracellular detoxification reactions. One of these, GSTπ, is elevated in some breast cancer cells, particularly cells selected for resistance to anticancer agents. We evaluated GSTπ expression in 60 human breast tumors by three techniques, immunohistochemistry, Northern hybridization, and Western blot analysis. There was a significant positive correlation between the three methods, with complete concordance seen in 64% of the tumors. There was strong, inverse relationship between GSTπ expression and steroid receptor status with all of the techniques utili zed. [n addition, there was a trend toward higher GSTπ expression in poorly differentiated tumors, but no correlation was found between tumor GSTπ content and DNA ploidy or %S-phase. GSTπ expression was also detected in adjacent benign breast tissue as well as infiltrating lymphocytes; this expression may contribute to GSTπ measurements using either Northern hybridization or Western blot analysis. These re sults suggest that immunohistochemistry is the method of choice for measuring GSTπ in breast tumors.

  15. Optical coherence tomography (OCT) as a 3-dimensional imaging technique for non-destructive testing of roll-to-roll coated polymer solar cells

    DEFF Research Database (Denmark)

    Thrane, Lars; Jørgensen, Thomas Martini; Jørgensen, Mikkel

    2013-01-01

    We have recently demonstrated the first application of optical coherence tomography (OCT) as a 3-dimensional (3D) imaging technique to visualize the internal structure of complete multilayered polymer solar cell modules (Thrane et al., Solar Energy Materials & Solar Cells 97, 181-185 (2012)). The...

  16. Analysis of Sperm Membrane Protein Relevant to Antisperm Antibody by Two-Dimensional Gel Electrophoresis and Western Blotting

    Institute of Scientific and Technical Information of China (English)

    Hao-fei WANG; Zhu-qiong XIANG; Yi-xing WANG

    2003-01-01

    Objective To identify the sperm membrane proteins that are associated with antisperm antibodyMethods Using antisperm antibody positive serum through unidimensional polyacrylamide gel electrophoresis and 2-dimensional gel electrophoresis followed by Western blot analysis to determine the molecular weights (MW) and isoelectric points (pI) of sperm membrane proteins that are associated with antisperm antibody.Results Eight kinds of MW with more than ten sperm membrane proteins can be recognized by antisperm antibody positive serum, of which the MWs and pI were 23 kD, 31 kD, 32 kD, 34 kD, 41 kD, 51 kD, 60 kD, 78 kD and 5.3, 5.5,5.7, 5.0, 5.3, 5.8, 6.0, 5.5~6.2, 4.6,5.1,5.5~5.8 respectively. The identification ratios of the sperm membrane proteins on 78 kD (60.7%), 60 kD (71.4%), 51 kD (14.9%) and 23 kD (14.29%) were higher.Conclusion The sperm membrane proteins with MW of 78 kD, 60 kD, 51 kD and 23 kD were associated with antisperm antibody and immunological infertility. Two-dimensional gel electrophoresis and Western blotting can precisely identify the sperm membrane proteins that are associated with antisperm antibody.

  17. Dot-Blot Hybridization for Detection of Five Cucurbit Viruses by Digoxigenin-Labelled cDNA Probes

    Institute of Scientific and Technical Information of China (English)

    MENG Juan; GU Qin-sheng; LIN Shi-ming; PENG Bin; LIU Li-feng; TIAN Yan-ping; LI Li

    2007-01-01

    Dot-blot hybridization was applied in this paper to detect five viruses infecting cucurbitaceous crops,Zuccini yellow mosaic virus(ZYMV),Watermelon mosaic virus(WMV),Cucumber mosaic virus(CMV),Papaya ringspot virus watermelon strain(PRSV-W)and Squash mosaic virus(SqMV),as a good alternative assay in seed health test and epidemiological and transgenic research.Digoxigenin-labelled cDNA probes of the five viruses were synthesized by PCR with the specific primers and applied in dot-blot hybridization to detect five viruses in crude extraction of the infected leaves.And three SqMV probes of different lengths(0.55,1.6,and 2.7 kb,respectively)were designed to investigate the effect of hybridization.The results showed that the sensitivity for detecting the crude extraction of infected leaves by ZYMV,WMV,CMV,PRSV-W,and SqMV was down to 1:160,1:160,1:320,1:160,and 1:320,respectively.Three SqMV probes of different length showed no differences on the sensitivity and specificity.The digoxigenin-labelled probes prepared by PCR could be used for accurate and rapid identification of 5 viruses infecting cucurbitaceous crops with good stabilities,sensitivities,specificity,and reproducibilities.

  18. RT-PCR and Northern blot analysis in search for a putative Paramecium beta-adrenergic receptor.

    Science.gov (United States)

    Płatek, A; Wiejak, J; Wyroba, E

    1999-01-01

    RT-PCR and Northern blot analysis were performed in order to search for a putative beta-adrenergic receptor (beta-AR) in Paramecium using several beta2-adrenergic-specific molecular probes. Under strictly defined RT-PCR conditions DNA species of expected molecular size about 360 bp were generated with the primers corresponding to the universal mammalian beta2-AR sequence tagged sites (located within the 4th and the 6th transmembrane regions of the receptor). This RT-PCR product hybridized in Southern blot analysis with the oligonucleotide probe designed to the highly conservative beta2-AR region involved in G-proteins interaction and located within the amplified region. Northern hybridization was performed on Paramecium total RNA and mRNA with human beta2-AR cDNA and two oligonucleotide probes: the first included Phe 290 involved in agonist binding (Strader et al., 1995) and the second was the backward RT-PCR primer. All these probes revealed the presence of about 2 kb mRNA which is consistent with the size of beta2-AR transcripts found in higher eukaryotes.

  19. Mere end blot pirringer

    DEFF Research Database (Denmark)

    Jantzen, Christian; Østergaard, Per

    2006-01-01

    Med udgangspunkt i en række cases på vellykkede oplevelsesøkonomiske forretningsmodeller argumenterer artiklen for, at oplevelsesprodukter skal bygge på et klart tema, som forbrugeren kan koble sig sanse- og følelsesmæssigt op på. Forbrugeren skal kunne omsætte produktets pirringer til egne erfar...

  20. Evaluation of agglutination strength by a flow-induced cell movement assay based surface plasmon resonance (SPR) technique.

    Science.gov (United States)

    Sudprasert, Krisda; Peungthum, Patjaree; Vongsakulyanon, Apirom; Amarit, Ratthasart; Somboonkaew, Armote; Sutapun, Boonsong; Kitpoka, Pimpun; Kunakorn, Mongkol; Srikhirin, Toemsak

    2015-02-07

    A flow-induced cell movement assay combined with a surface plasmon resonance (SPR) technique was developed to quantify the agglutination strength, derived from the standard tube-agglutination test. Red blood cells (RBCs), based on the ABO blood group system, were specifically captured by anti-A and/or anti-B antibodies immobilized on a sensor surface. The agglutination strength corresponds to the amount of antigen-antibody interactions or the strength of RBC adhesion. Under a shear flow, the adherent RBCs were forced to move out of the region of interest with different average cell velocities (vc) depending upon the adhesion strength and wall shear stress (WSS). That is, a higher adhesion strength (higher agglutination strength) or lower WSS represents a lower vc or vice versa. In this work, the agglutination strength was derived from the vc that was calculated from the time derivative of the relative SPR signal by using a simple model of cell movement response, whose validity was verified. The vc values of different samples were correlated with their agglutination strengths at a given WSS and antibody surface density. The vc decreased as the agglutination strength increased, which can be considered as a linear regression. The coefficient of variation of the calculated vc decreased to 0.1 as vc increased to 30 μm min(-1). The sensitivity of this assay can be controlled by optimizing the antibody surface density or the WSS. This assay has the capability to resolve the antigen density of A1 and B RBCs from that of A1B RBCs.

  1. Detection of the interaction between SNAP25 and rabphilin in neuroendocrine PC12 cells using the FLIM/FRET technique.

    Science.gov (United States)

    Lee, Jiung-De; Chang, Yu-Fen; Kao, Fu-Jen; Kao, Lung-Sen; Lin, Chung-Chih; Lu, Ai-Chu; Shyu, Bai-Chuang; Chiou, Shih-Hwa; Yang, De-Ming

    2008-01-01

    Exocytosis has been proposed to contain four sequential steps, namely docking, priming, fusion, and recycling, and to be regulated by various proteins-protein interactions. Synaptosomal-associated protein of 25 kDa (SNAP25) has recently been found to bind rabphilin, the Rab3A specific binding protein, in vitro. However, it is still unclear whether SNAP25 and rabphilin interact during exocytosis within cells in vivo. This problem was addressed by the integration of fluorescence resonance energy transfer (FRET) with high sensitivity fluorescence lifetime imaging microscopy (FLIM) to observe this protein-protein interaction. Enhanced green fluorescence protein-labeled SNAP25 (donor) and red fluorescence protein-labeled rabphilin (acceptor) were expressed in neuroendocrine PC12 cells as a FRET pair and ATP stimulation was carried out for various durations. With 10 s stimulation, a 0.17-ns left shift of the lifetime peak was found when compared with donor only. Analysis of the lifetime image further suggested that the lifetime recovered to a similar level as the donor only in a time dependent manner. Four-dimensional (4D) images by FLIM provided useful information indicating that the interaction of SNAP25 and rabphilin occurred particularly within optical sections near cell membrane. Together the results suggest that SNAP25 bound rabphilin loosely at docking step before exocytosis and the binding became tighter at the very start of exocytosis. Finally, these two proteins dissociated after stimulation. To our knowledge, this is the first report to demonstrate the interaction of SNAP25 and rabphilin in situ using the FLIM-FRET technique within neuroendocrine cells.

  2. Efficiency Enhancement of Pico-cell Base Station Power Amplifier MMIC in Gallium Nitride HFET Technology Using the Doherty technique

    Science.gov (United States)

    Seneviratne, Sashieka

    With the growth of smart phones, the demand for more broadband, data centric technologies are being driven higher. As mobile operators worldwide plan and deploy 4th generation (4G) networks such as LTE to support the relentless growth in mobile data demand, the need for strategically positioned pico-sized cellular base stations known as 'pico-cells' are gaining traction. In addition to having to design a transceiver in a much compact footprint, pico-cells must still face the technical challenges presented by the new 4G systems, such as reduced power consumptions and linear amplification of the signals. The RF power amplifier (PA) that amplifies the output signals of 4G pico-cell systems face challenges to minimize size, achieve high average efficiencies and broader bandwidths while maintaining linearity and operating at higher frequencies. 4G standards as LTE use non-constant envelope modulation techniques with high peak to average ratios. Power amplifiers implemented in such applications are forced to operate at a backed off region from saturation. Therefore, in order to reduce power consumption, a design of a high efficiency PA that can maintain the efficiency for a wider range of radio frequency signals is required. The primary focus of this thesis is to enhance the efficiency of a compact RF amplifier suitable for a 4G pico-cell base station. For this aim, an integrated two way Doherty amplifier design in a compact 10mm x 11.5mm2 monolithic microwave integrated circuit using GaN device technology is presented. Using non-linear GaN HFETs models, the design achieves high effi-ciencies of over 50% at both back-off and peak power regions without compromising on the stringent linearity requirements of 4G LTE standards. This demonstrates a 17% increase in power added efficiency at 6 dB back off from peak power compared to conventional Class AB amplifier performance. Performance optimization techniques to select between high efficiency and high linearity operation are

  3. Plant tissue culture techniques

    OpenAIRE

    Rolf Dieter Illg

    1991-01-01

    Plant cell and tissue culture in a simple fashion refers to techniques which utilize either single plant cells, groups of unorganized cells (callus) or organized tissues or organs put in culture, under controlled sterile conditions.

  4. Plant tissue culture techniques

    Directory of Open Access Journals (Sweden)

    Rolf Dieter Illg

    1991-01-01

    Full Text Available Plant cell and tissue culture in a simple fashion refers to techniques which utilize either single plant cells, groups of unorganized cells (callus or organized tissues or organs put in culture, under controlled sterile conditions.

  5. Insights into the prominent effect of mahanimbine on Acanthamoeba castellanii: Cell profiling analysis based on microscopy techniques

    Science.gov (United States)

    Hashim, Fatimah; Amin, Nakisah Mat

    2017-02-01

    Mahanimbine (MH), has been shown to have antiamoeba properties. Therefore, the aim of this study was to assess the growth inhibitory mechanisms of MH on Acanthamoeba castellanii, a causative agents for Acanthamoeba keratitis. The IC50 value obtained for MH against A. castellanii was 1.18 µg/ml. Light and scanning electron microscopy observation showed that most cells were in cystic appearance. While transmission electron microscopy observation revealed changes at the ultrastructural level and fluorescence microscopy observation indicated the induction of apoptosis and autophagic activity in the amoeba cytoplasms. In conclusion, MH has very potent anti-amoebic properties on A. castellanii as is shown by cytotoxicity analyses based on microscopy techniques.

  6. Value of window technique in diagnosis of the ground glass opacities in patients with non-small cell pulmonary cancer.

    Science.gov (United States)

    Yao, Gang

    2016-11-01

    The aim of the present study was to examine the value of window technique in qualitative diagnosis of the ground glass opacities (GGO) in patients with non-small cell pulmonary cancer. A total of 124 clinically suspected pulmonary cancer patients were analyzed retrospectively. The lesions were affirmed by puncture biopsy, and were GGO on pulmonary window while were invisible on mediastinal window. Sixty-four multi-detector spiral computed tomography with the window width and window level of 1,500 Hounsfield units (HU) and -450 HU on pulmonary window, while the window width and window level of 400 and 40 HU on mediastinal window, was used in the study. The window adjustment technique was used to analyze the window width and window level of lesion on pulmonary window and mediastinal window, for searching invisible threshold on 3-megapixel medical displays. The diagnostic accuracy and the cut-off value were compared on receiver operating characteristic (ROC) curve. The results showed that the window width and window level on pulmonary window and mediastinal window of malignant lesions were significantly less than those of benign ones (Pvalue on pulmonary window was the window width and window level of 1,300 and -220 HU, the area under the ROC was 0.830 [sensitivity was 72.5%, specificity was 84.3%; 95% confidence interval (CI), 0.712-0.945]. The cut-off value on mediastinal window was the window width and window level of 360 and 30 HU, and the area under the ROC was 0.623 (was 62.0%, specificity was 55.7%; 95% CI, 0.541-0.745). In conclusion, the window technique has high sensitivity and accuracy in qualitative diagnosis of the GGO.

  7. The application of a photon-counting camera in very sensitive, bioluminescence-enhanced detection systems for protein blotting. Ultrasensitive detection systems for protein blotting and DNA hybridization, II.

    Science.gov (United States)

    Hauber, R; Miska, W; Schleinkofer, L; Geiger, R

    1988-03-01

    A relatively simple, very sensitive bioluminescence-enhanced detection system for protein blots was described recently. This method utilizes antibodies conjugated with alkaline phosphatase. Alkaline phosphatase releases D-luciferin (Photinus pyralis) from D-luciferin-O-phosphate. Liberated D-luciferin reacts with luciferase, ATP and oxygen with light emission. The light produced is measured with a very sensitive photon counting camera (Argus 100), permitting visualization and localization of the alkaline phosphatase-conjugated antibodies on nitrocellulose sheets. Under non-optimized conditions the limit of detection is at present 5 to 500 fg of protein (rabbit immunoglobulin G), corresponding to 30 to 3 amol. The method is therefore 10(5) times more sensitive than other used at present.

  8. Western blot data using two distinct anti-O-GlcNAc monoclonal antibodies showing unique glycosylation status on cellular proteins under 2-deoxy-d-glucose treatment

    Directory of Open Access Journals (Sweden)

    Tetsuya Okuda

    2017-02-01

    Full Text Available Protein modification by O-linked N-acetylglucosamine (O-GlcNAcylation is one of the post transcriptional modifications occurring on cellular proteins. This paper provides a data set relating to the O-GlcNAcylation of cellular proteins detected by RL2 and CTD110.6 antibodies, which are commonly used for detection of protein O-GlcNAcylation, in 2-deoxy-d-glucose (2DG-treated human teratocarcinoma NCCIT cells in support of the research article entitled “A novel, promoter-based, target-specific assay identifies 2-deoxy-d-glucose as an inhibitor of globotriaosylceramide biosynthesis” (Okuda et al., 2009 [1]. The main article described a suppressive effect of 2DG on an Sp1 target gene in NCCIT cells and discussed the relationship between the effect of 2DG and O-GlcNAcylation status of Sp1. The data in this paper complements this relationship by Western blotting and clearly showed that the 2DG treatment increased O-GlcNAcylation of cellular proteins in NCCIT cells, whereas the RL2 and CTD110.6 epitopes were detected in a different manner. The RL2 epitope was detected on Sp1 during 2DG treatment, and the level was transiently increased at 24 h. In contrast, the CTD110.6 epitope became detectable on Sp1 over 72 h after 2DG treatment, and then the other proteins containing CTD110.6 epitopes also appeared in the cell lysates and the anti-Sp1 antibody precipitates.

  9. Autologous Stem Cell Application in Periodontal Regeneration Technique (SAI-PRT) Using PDLSCs Directly From an Extracted Tooth···An Insight.

    Science.gov (United States)

    Vandana, K L; Desai, Rajendra; Dalvi, Priyanka Jairaj

    2015-11-01

    Periodontal regeneration represents the ultimate goal of periodontal therapy. The current regenerative techniques have limited success rates especially in advanced periodontal defects. Currently the research is focused on novel cell-based approaches for periodontal regeneration to overcome the limitations of existing treatment. The human clinical trial on stem cells based periodontal regeneration is promising. The plethora of animal studies provide sound evidence to support the belief that periodontal ligament stem cells (PDLSCs) can be used for periodontal regeneration. The direct application of autologous periodontal stem cells in treatment of intrabony defects is attempted for the first time in periodontal literature. Stem cell Application in Periodontal Regeneration Technique (SAI-PRT) using direct PDLSCs has overcome the limitations and concerns of ex- vivo stem cell culture methods like high cost, technique sensitivity, loss of stemness during cell passage, genetic manipulation and tumorigenic potential. Clinical feasibility, success and cost effectiveness over currently available techniques are encouraging. The clinical utility of this novel idea is recommended.

  10. Autologous Stem Cell Application in Periodontal Regeneration Technique (SAI-PRT) Using PDLSCs Directly From an Extracted Tooth···An Insight

    Science.gov (United States)

    Vandana, KL; Desai, Rajendra; Dalvi, Priyanka Jairaj

    2015-01-01

    Periodontal regeneration represents the ultimate goal of periodontal therapy. The current regenerative techniques have limited success rates especially in advanced periodontal defects. Currently the research is focused on novel cell-based approaches for periodontal regeneration to overcome the limitations of existing treatment. The human clinical trial on stem cells based periodontal regeneration is promising. The plethora of animal studies provide sound evidence to support the belief that periodontal ligament stem cells (PDLSCs) can be used for periodontal regeneration. The direct application of autologous periodontal stem cells in treatment of intrabony defects is attempted for the first time in periodontal literature. Stem cell Application in Periodontal Regeneration Technique (SAI-PRT) using direct PDLSCs has overcome the limitations and concerns of ex- vivo stem cell culture methods like high cost, technique sensitivity, loss of stemness during cell passage, genetic manipulation and tumorigenic potential. Clinical feasibility, success and cost effectiveness over currently available techniques are encouraging. The clinical utility of this novel idea is recommended. PMID:26634072

  11. Use of an Electrochemical Split Cell Technique to Evaluate the Influence of Shewanella oneidensis Activities on Corrosion of Carbon Steel.

    Science.gov (United States)

    Miller, Robert Bertram; Sadek, Anwar; Rodriguez, Alvaro; Iannuzzi, Mariano; Giai, Carla; Senko, John M; Monty, Chelsea N

    2016-01-01

    Microbially induced corrosion (MIC) is a complex problem that affects various industries. Several techniques have been developed to monitor corrosion and elucidate corrosion mechanisms, including microbiological processes that induce metal deterioration. We used zero resistance ammetry (ZRA) in a split chamber configuration to evaluate the effects of the facultatively anaerobic Fe(III) reducing bacterium Shewanella oneidensis MR-1 on the corrosion of UNS G10180 carbon steel. We show that activities of S. oneidensis inhibit corrosion of steel with which that organism has direct contact. However, when a carbon steel coupon in contact with S. oneidensis was electrically connected to a second coupon that was free of biofilm (in separate chambers of the split chamber assembly), ZRA-based measurements indicated that current moved from the S. oneidensis-containing chamber to the cell-free chamber. This electron transfer enhanced the O2 reduction reaction on the coupon deployed in the cell free chamber, and consequently, enhanced oxidation and corrosion of that electrode. Our results illustrate a novel mechanism for MIC in cases where metal surfaces are heterogeneously covered by biofilms.

  12. Low platinum loading for high temperature proton exchange membrane fuel cell developed by ultrasonic spray coating technique

    Science.gov (United States)

    Su, Huaneng; Jao, Ting-Chu; Barron, Olivia; Pollet, Bruno G.; Pasupathi, Sivakumar

    2014-12-01

    This paper reports use of an ultrasonic-spray for producing low Pt loadings membrane electrode assemblies (MEAs) with the catalyst coated substrate (CCS) fabrication technique. The main MEA sub-components (catalyst, membrane and gas diffusion layer (GDL)) are supplied from commercial manufacturers. In this study, high temperature (HT) MEAs with phosphoric acid (PA)-doped poly(2,5-benzimidazole) (AB-PBI) membrane are fabricated and tested under 160 °C, hydrogen and air feed 100 and 250 cc min-1 and ambient pressure conditions. Four different Pt loadings (from 0.138 to 1.208 mg cm-2) are investigated in this study. The experiment data are determined by in-situ electrochemical methods such as polarization curve, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The high Pt loading MEA exhibits higher performance at high voltage operating conditions but lower performances at peak power due to the poor mass transfer. The Pt loading 0.350 mg cm-2 GDE performs the peak power density and peak cathode mass power to 0.339 W cm-2 and 0.967 W mgPt-1, respectively. This work presents impressive cathode mass power and high fuel cell performance for high temperature proton exchange membrane fuel cells (HT-PEMFCs) with low Pt loadings.

  13. 用DNA探针检测沙眼衣原体%Detection of Chlamydia Trachomatis by DNA Probe Blot

    Institute of Scientific and Technical Information of China (English)

    王卫萍; 陈亚利; 武建国

    2001-01-01

    目的: 建立一种敏感而特异的沙眼衣原体分子生物学检测方法. 方法: 用PCR扩增517bp的沙眼衣原体种特异性基因片段并标记成探针,建立DNA探针杂交检测沙眼衣原体的方法.结果: 探针只与沙眼衣原体L2、TE55株DNA呈阳性杂交斑点,与其他两种衣原体、解脲支原体、淋病奈瑟菌、大肠埃希菌、金黄色葡萄球菌、流感嗜血杆菌及白色念珠菌DNA斑点膜无阳性杂交信号.从100例慢性宫颈炎和前列腺炎病人生殖道分泌物中检出阳性22例,阳性率22%. 结论: 建立的DNA探针检测沙眼衣原体方法具有较高的敏感性和特异性,可用于批量临床标本的检测.%Objectives: To establish a sensitive and specific molecular biologicalmethod for detecting Chlamydia trachomatis of genital tract infection patients. Methods: A DNA blot assay was developed by coating DNA of Chlamydia trachomatisand/or extract of clinical samples on nitrocellulose (NC) membrane, blotting witha DNA probe labeled with DIG. Results: There was no positive blotting in Chlamydiapneumoniae, Chlamydia psittaci, Ureaplasma urealyticum, Neisseria gonorrhoeae,Esherichia coli, Staphylococcus aureus, Haemophilus infuenzae and Candida albicansexcept Chlamydia trachomatis. The sensitivity could be improved to 1pg. The positivepercentage was 22% (22/100) in detection of swabs collected from 100 chroniccervicitis and prostatitis patients. Conclusions: This method was not only sensitive, rapid and specific but also could be applied to detect batch samples. Natl J Androl,2001,7(2):102~104

  14. Standardisation of Western blotting to detect HTLV-1 antibodies synthesised in the central nervous system of HAM/TSP patients

    Directory of Open Access Journals (Sweden)

    Luiz Claudio Pereira Ribeiro

    2013-09-01

    Full Text Available Intrathecal synthesis of human T-lymphotropic virus type 1 (HTLV-1 antibodies (Abs represents conclusive evidence of a specific immune response in the central nervous system of HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP patients. Western blotting (WB for HTLV Abs in serum is a confirmatory test for HTLV-1 infection. The aim of this study was to standardise the Western blot to demonstrate the intrathecal pattern of Abs against HTLV-1 proteins in HAM/TSP patients. Paired cerebrospinal fluid (CSF and serum samples were selected from 20 patients with definite HAM/TSP, 19 HTLV-1 seronegative patients and two HTLV-1 patients without definite HAM/TSP. The presence of reactive bands of greater intensity in the CSF compared to serum (or bands in only the CSF indicated the intrathecal synthesis of anti-HTLV-1 Abs. All definite HAM/TSP patients presented with an intrathecal synthesis of anti-HTLV-1 Abs; these Abs were not detected in the control patients. The most frequent intrathecal targets of anti-HTLV-1 Abs were GD21, rgp46-I and p24 and, to a lesser extent, p19, p26, p28, p32, p36, p53 gp21 and gp46. The intrathecal immune response against env (GD21 and rgp46-I and gag (p24 proteins represents the most important humoral pattern in HAM/TSP. This response may be used as a diagnostic marker, considering the frequent association of intrathecal anti-HTLV-1 Ab synthesis with HAM/TSP and the pathogenesis of this neurological disease.

  15. Imprinting mutations in Angelman syndrome detected by Southern blotting using a probe containing exon {alpha} of SNRPN

    Energy Technology Data Exchange (ETDEWEB)

    Beuten, J.; Sutcliffe, J.S.; Nakao, M. [Baylor College of Medicine, Houston, TX (United States)] [and others

    1994-09-01

    Prader-Willi syndrome (PWS) and Angelman syndrome (AS) are associated with paternal and maternal deficiencies respectively, of gene expression within human chromosome 15q11-q13, and are caused by deletion, uniparental disomy (UPD), or other mutations. The SNRPN gene maps in this region, is paternally expressed, and is a candidate gene for PWS. Southern blotting using methylation-sensitive enzymes and a genomic DNA probe from the CpG island containing exon {alpha} of the SNRPN gene reveals methylation specific for the maternal allele. In cases of the usual deletions or UPD, the probe detects absence of an unmethylated allele in PWS and absence of a methylated allele in AS. We have analyzed 21 nondeletion/nonUPD AS patients with this probe and found evidence for an imprinting mutation (absence of a methylated allele) in 3 patients. Southern blotting with methylation-sensitive enzymes using the exon {alpha} probe, like use of the PW71 probe, should detect abnormalities in all known PWS cases and in 3 of the 4 forms of AS: deletion, UPD and imprinting mutations. This analysis provides a valuable diagnostic approach for PWS and AS. In efforts to localize the imprinting mutations in AS, one patient was found with failure to inherit a dinucleotide repeat polymorphism near probe 189-1 (D15S13). Analysis of this locus in AS families and CEPH families demonstrates a polymorphism that impairs amplification and a different polymorphism involving absence of hybridization to the 189-1 probe. The functional significance, if any, of deletion of the 189-1 region is unclear.

  16. MDR-TB Antibody Response (Western Blot) to Fractions of Isoniazid and Rifampicin Resistant Antigens of Mycobacterium tuberculosis.

    Science.gov (United States)

    Hadizadeh Tasbiti, Alireza; Yari, Shamsi; Ghanei, Mostafa; Shokrgozar, Mohammad Ali; Bahrmand, Ahmadreza

    2015-12-01

    Drug-resistant TB poses a major threat to control of TB worldwide. Despite progress in the detection of Multidrug-resistant TB (MDR-TB) cases, a major diagnostic gap remains: 55% of reported TB patients estimated to have MDR-TB were not detected in 2013. MDR-TB antigens were conjugated to CNBr-activated Sepharose 4B. Specific polyclonal antibodies against MDR-TB Ags were prepared in rabbits using two boosted injections of the MDR-TB antigen. The antibodies were purified and treated with susceptible TB to remove any non-specific and cross-reactive antibodies. In the present study, comparative analysis of electrophoretic pattern of different antigens of INH/RIF-resistant TB were studied for identifying protein profiles. A RIF-resistant TB antigen was shown here to have different protein profiles from INH-resistant TB isolate. The results of Western blotting analysis showed that in the RIF- and INH-resistant antigenic fractions some bands of 14.4 and 45 kDa as immunogenic were common. Moreover, four bands of RIF-resistant TB antigen fractions (16, 19, 21, and 45 KDa) and one band of INH-resistant TB (about 26 KDa) were detected as diagnostic antigens. This study suggests that the Western blot is an accurate test to survey INH- and RIF-resistant TB antigens of M. tuberculosis infection. These findings indicate that MDR-TB diagnosis (based on Ag detection) could be useful in the identification of disease stages that precede symptomatic and microbiologically positive TB, such as subclinical and incipient TB.

  17. Investigation of simple IMRT delivery techniques for non-small cell lung cancer patients with respiratory motion using 4DCT.

    Science.gov (United States)

    Reitz, Bodo; Parda, David S; Colonias, Athanasios; Lee, Vincent; Miften, Moyed

    2009-01-01

    Techniques for generating simplified IMRT treatment plans for treating non-small cell lung cancer (NSCLC) patients with respiratory motion were investigated. To estimate and account for respiratory motion, 4-dimensional computed tomography (4DCT) datasets from 5 patients were used to design 5-field 6-MV ungated step-and-shoot intensity modulated radiotherapy (IMRT) plans delivering a dose of 66 Gy to the planning target volume (PTV). For each patient, 2 plans were generated using the mean intensity and the maximum intensity of 10 CT datasets from different breathing phases. The plans also utilized different margins around the clinical target volume/internal target volume (CTV/ITV) to account for tumor motion. To reduce the treatment time and ensure accurate dose delivery to moving targets, the number of intensity levels was minimized while maintaining dose coverage to PTV and minimizing dose to organs at risk (OARs). Dose-volume histograms (DVHs), dosimetric metrics, and outcome probabilities were evaluated for all plans. Plans using the averaged CT image dataset were inferior, requiring larger margins around the PTV, with a maximum of 1.5 cm, to ensure coverage of the tumor, and therefore increased the dose to OARs located in proximity of the tumor. The plans based on superimposed CT image datasets achieved full coverage of the tumor, while allowing tight margins around the PTV and minimizing the dose to OARs. A small number of intensity-levels (3 to 5), resulting in IMRT plans with a total of 13 to 30 segments, were sufficient for homogeneous PTV coverage, without affecting the sparing of OARs. In conclusion, a technique involving treatment planning with the superimposed CT scans of all respiratory phases, and the application of IMRT with only a small number of segments was feasible despite significant tumor motion; however, greater patient numbers are needed to support the statistical significance of the results presented in this work.

  18. Total Skin Electron Therapy for Cutaneous T-Cell Lymphoma Using a Modern Dual-Field Rotational Technique

    Energy Technology Data Exchange (ETDEWEB)

    Heumann, Thatcher R. [Emory University School of Medicine, Emory University, Atlanta, Georgia (United States); Esiashvili, Natia [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute (WCI), Emory University, Atlanta, Georgia (United States); Parker, Sareeta [Department of Dermatology, Emory University, Atlanta, Georgia (United States); Switchenko, Jeffrey M. [Biostatistics Shared Core Resource at WCI, Emory University, Atlanta, Georgia (United States); Dhabbaan, Anees [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute (WCI), Emory University, Atlanta, Georgia (United States); Goodman, Michael [Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, Georgia (United States); Lechowicz, Mary Jo; Flowers, Christopher R. [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Department of Hematology and Oncology, Emory University, Atlanta, Georgia (United States); Khan, Mohammad K., E-mail: drkhurram2000@gmail.com [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute (WCI), Emory University, Atlanta, Georgia (United States)

    2015-05-01

    Purpose: To report our experience with rotational total skin electron irradiation (RTSEI) in cutaneous T-cell lymphoma (CTCL), and to examine response by disease stage and race. Methods and Materials: We reviewed our outcomes for 68 CTCL patients who received RTSEI (≥30 Gy) from 2000 to 2013. Primary outcomes were complete clinical response (CCR), recurrence-free survival (RFS), and overall survival (OS). Using log–rank tests and Cox proportional hazards, OS and RFS were compared across tumor stages at time of RTSEI with further racial subgroup analysis. Results: Median age at diagnosis and at time of radiation was 52 and 56 years, respectively. Median follow-up was 5.1 years, 49% were African American, and 49% were female. At time of treatment, 18, 37, and 13 patients were T stage 2, 3, and 4, respectively. At 6 weeks after RTSEI, overall CCR was 82% (88%, 83%, and 69% for T2, T3, and T4, respectively). Median RFS was 11 months for all patients and 14, 10, and 12 months for stage T2, T3, and T4, respectively. Tumor stage was not associated with RFS or CCR. Maintenance therapy after RTSEI was associated with improved RFS in both crude and multivariable analysis, controlling for T stage. Median OS was 76 months (91 and 59 months for T3 and T4, respectively). With the exception of improved OS in African Americans compared with whites at stage T2, race was not associated with CCR, RFS, or OS. Conclusions: These results represent the largest RTSEI clinical outcomes study in the modern era using a dual-field rotational technique. Our observed response rates match or improve upon the standard set by previous outcome studies using conventional TSEI techniques, despite a large percentage of advanced CTCL lesions in our cohort. We found that clinical response after RTSEI did not seem to be affected by T stage or race.

  19. Immunohistochemical and Western blot analysis of two protein tyrosine phosphatase receptors, R and Z1, in colorectal carcinoma, colon adenoma and normal colon tissues.

    Science.gov (United States)

    Woźniak, Marta; Gamian, Elżbieta; Łaczmańska, Izabela; Sąsiadek, Maria M; Duś-Szachniewicz, Kamila; Ziółkowski, Piotr

    2014-05-01

    Two classes of proteins, namely tyrosine kinases (PTK) and phosphatases (PTP), play an important role in cell proliferation and differentiation, thus leading to an acceleration or inhibition of tumour growth. The role of the above proteins in colorectal carcinoma (CRC) growth is a well-known event. In this study we carried out immunohistochemical and Western blot analysis of colorectal carcinoma, adenoma and normal colon tissue in relation to two protein tyrosine phosphatase receptors, R and Z1. Twenty-five cases of CRC were analyzed and the results were compared with similar data obtained in non-malignant tissues. High expression of both PTP receptors was observed in all examined cases of CRC, adenoma and normal colon tissue in this study. These results are not in line with recently published data, showing that genetic coding for PTPRR and PTPRZ1 were hypermethylated in CRC's. We presume that the protein tyrosine phosphatase overexpression in colorectal carcinoma is not enough to protect from the progression of disease.

  20. Direct measurement of tubulin and bulk message distributions on polysomes of growing, starved and deciliated Tetrahymena using RNA gel blots of sucrose gradients containing acrylamide.

    Science.gov (United States)

    Calzone, F J; Callahan, R; Gorovsky, M A

    1988-10-25

    A method was developed using sucrose gradients containing acrylamide which greatly simplifies the measurement of the polysomal distribution of messages. After centrifugation, the acrylamide was polymerized, forming a "polysome gel". RNA gel blots of polysome gels were used to determine the polysomal distributions of alpha-tubulin and total polyadenylated mRNA in growing, starved (nongrowing) and starved-deciliated Tetrahymena and the number of messages loaded onto polysomes was calculated. These measurements indicated that the translational efficiencies of alpha-tubulin mRNA and total polyadenylated mRNA are largely unaffected when the rates of tubulin and total protein synthesis vary dramatically. Thus, differential regulation of alpha-tubulin mRNA translation initiation does not contribute to the greater than 100-fold induction of tubulin synthesis observed during cilia regeneration and in growing cells. The major translation-level process regulating tubulin synthesis in Tetrahymena appears to be a change in message loading mediated by a non-specific message recruitment or unmasking factor.

  1. Flow cytometry of nucleated red blood cells used as monitoring technique for aquatic risk assessment. A review.

    Directory of Open Access Journals (Sweden)

    Bratosin D.

    2016-05-01

    Full Text Available During the last decades anthropogenic factors led to a significant enhancement of pollutants in aquatic environment and for several years, chemicals analysis has been commonly employed. These techniques cannot detect and quantify many environmental phenomena such as bioavailability, bioaccumulation and synergistic effects. For these reasons, many investigations for evaluating the effects of xenobiotic on organisms use in vitro or in vivo bioassays. The bioassays give a global response for all chemicals present in the environment and these represent one of the best ways to estimate the risk assessment of pollutants in environment for monitoring. For assessing cytotoxicity or ecotoxicity of pollutants (heavy metals, nanoparticles, etc. and to assess aquatic pollution degree and biomonitoring of Danube River and Danube Delta, we developed a new experimental cell system based on the apoptosis of nucleated erythrocytes from fishes and batrachians which are directly exposed to pollutants absorbed by different ways. Despite their structural simplicity, the erythrocytes of lower vertebrates preserve nucleus and mitochondria, both the sensors of the programmed cell death (PCD machinery to develop an apoptosis phenomenon. Our proposed bioassays which are based on the apoptosis phenomenon as induced biomarker by pollutants on fish or amphibians erythrocytes, evidenced by flow cytometry (apoptosis/necrosis discriminated by FITC-annexin-V labeling/PI and cellular viability measured with calcein-AM method could be rapid and very sensitive tests for in laboratory aquatic risk assessment and biomonitoring. Standardization and application of these tests will surely provide the opportunity of their use easily in ecotoxicological laboratories, biomonitoring of large river basins such as the Danube River Basin and will be also able deliver information on fish as a food product.

  2. Defect recognition by means of light and electron probe techniques for the characterization of mc-Si wafers and solar cells

    Science.gov (United States)

    Moralejo, B.; Tejero, A.; Hortelano, V.; Martínez, O.; González, M. A.; Jiménez, J.

    2016-11-01

    Multicristalline Silicon (mc-Si) is the preferred material for current terrestrial photovoltaic applications. However, the high density of defects present in mc-Si deteriorates the material properties, in particular the minority carrier diffusion length. For this reason, a large effort to characterize the mc-Si material is demanded, aiming to visualize the defective areas and to quantify the type of defects, density and its origin. In this work, several complementary light and electron probe techniques are used for the analysis of both mc-Si wafers and solar cells. These techniques comprise both fast and whole-area detection techniques such as Photoluminescence imaging, and highly spatially resolved time consuming techniques, such as light and electron beam induced current techniques and μRaman spectroscopy. These techniques were applied to the characterization of different mc-Si wafers for solar cells, e.g. ribbon wafers, cast mc-Si as well as quasi-monocrystalline material, upgraded metallurgical mc-Si wafers, and finished solar cells.

  3. Morphological studies of vertical arrays TiO2 nanotubes by electrochemical anodization technique for dye sensitized solar cell application

    Science.gov (United States)

    Su'ait, M. S.; Alamgir, F.; Scardi, P.; Ahmad, A.

    2013-11-01

    A vertical array titanium dioxide nanotube (n-TiO2) for photovoltaic materials in dye sensitized solar cell has been synthesized by electrochemical anodization technique in NH4F aqueous solution. The morphological observation performed by SEM analysis on the scratch film showed that the distribution growths of TiO2 nanotubes on Ti subtract were uniform. The duration of growth is varied up to 12 h, with tubes length approximately 1 μm. However, at the maximum duration, a compact TiO2 layers were formed. This phenomenon is due to the field-assisted anodic oxidation at the interfaces of Ti/TiO2 is at equal rate with the field-assisted dissolution rate of the top TiO2 nanotube's surface, resulting from the decreased quantity of F- ions to form fluoro complexes, [TiF6]2-. A slight increase in the rate of the chemical dissolution reaction produced a precipitated TiO2. Hence, [TiF6]2- complexes which are required for tubes formation are difficult to exist.

  4. Hybrid approach combining multiple characterization techniques and simulations for microstructural analysis of proton exchange membrane fuel cell electrodes

    Science.gov (United States)

    Cetinbas, Firat C.; Ahluwalia, Rajesh K.; Kariuki, Nancy; De Andrade, Vincent; Fongalland, Dash; Smith, Linda; Sharman, Jonathan; Ferreira, Paulo; Rasouli, Somaye; Myers, Deborah J.

    2017-03-01

    The cost and performance of proton exchange membrane fuel cells strongly depend on the cathode electrode due to usage of expensive platinum (Pt) group metal catalyst and sluggish reaction kinetics. Development of low Pt content high performance cathodes requires comprehensive understanding of the electrode microstructure. In this study, a new approach is presented to characterize the detailed cathode electrode microstructure from nm to μm length scales by combining information from different experimental techniques. In this context, nano-scale X-ray computed tomography (nano-CT) is performed to extract the secondary pore space of the electrode. Transmission electron microscopy (TEM) is employed to determine primary C particle and Pt particle size distributions. X-ray scattering, with its ability to provide size distributions of orders of magnitude more particles than TEM, is used to confirm the TEM-determined size distributions. The number of primary pores that cannot be resolved by nano-CT is approximated using mercury intrusion porosimetry. An algorithm is developed to incorporate all these experimental data in one geometric representation. Upon validation of pore size distribution against gas adsorption and mercury intrusion porosimetry data, reconstructed ionomer size distribution is reported. In addition, transport related characteristics and effective properties are computed by performing simulations on the hybrid microstructure.

  5. Effect of ethanolic extract of propolis on cell viability of chinese hamster ovary cells (CHO-K1) irradiated with {sup 60}CO gamma-rays using differential staining technique

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Marcos P.M. de; Castro, Renato F. de; Okazaki, Kayo; Vieira, Daniel P., E-mail: dpvieira@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The objective of present study was to assess the effect of Brazilian propolis (AF-08) on CHO-K1 cells irradiated with {sup 60}Co, through the differential staining technique, using acridine orange and ethidium bromide. The cells were pre-incubated with different concentrations of propolis (50, 100 and 200 μg/mL) for 24h and irradiated with 5 Gy, analyzed at 24 and 48h after exposure. This technique is based on the cell capacity to incorporate fluorescent DNA dyes, where the viable (green), apoptotic (orange/yellow) and necrotic (red) cells can be identified through fluorescence microscopy. Digital high-resolution images were acquired from at least 5 visualization fields, and cells were analyzed using ImageJ and Flowing software. This approach permitted to analyze a large number of cells/sample with the time reduction, much easier and faster, proportioning more statistical power of the technique. The treatment with propolis only was not cytotoxic at 24 and 48h, except for the higher concentration of 200 μg/mL associated or not with radiation, increasing apoptotic and mainly necrotic cells (p<0.001). The data showed a promising use of propolis as well as technique used, pointing out that 200 μg/mL of propolis was cytotoxic, but at lower one (50 μg/mL) presented a radioprotective effect in irradiated CHO-K1 cells. (author)

  6. Spectrophotometric quantitation of DNA on blots after ethanol-solubilization of the MTT-formazan from anti-digoxigenin-based detection of nucleic acids.

    Science.gov (United States)

    Colgan, D J

    1993-01-01

    The tetrazolium salt, 3-(4,5-dimethyl-thiazolyl-2)-2,5-diphenyl tetrazolium bromide (MTT) has recently been established as a substitute for Nitro-blue tetrazolium (NBT) in stain mixtures using antibody-conjugated alkaline phosphatase for the location of proteins on Western blots (Heegaard, 1990). Experiments reported here show that MTT is as sensitive as NBT in digoxigenin-labeled probe localization (on nucleic acid blots) utilizing alkaline-phosphatase-labelled, anti-digoxigenin antibodies. Moreover, as the formazan from MTT is soluble in ethanol, it is shown that spectrophotometric quantitation can be used to estimate the amount of target DNA on dot and Southern blots. For dot blotting, pBR328 was used as the probe and pBR322 as target. For Southern blots, human rDNA was used as the probe and total genomic calf DNA as the target. Staining response was linear over at least six twofold DNA dilutions in both types of blot.

  7. The Characteristics of Murine iPS Cells and siRNA Transfection Under Hypoxia.

    Science.gov (United States)

    Sugimoto, K; Hayashi, Yoshihiko

    2016-01-01

    iPS cells are attractive for the regenerative medicine. The creation of pluripotent cells from somatic cells has great potential for basic and clinical research and application. Retroviral transduction of four or three transfection factors has been shown to initiate a reprogramming process. Here, we describe the effect of transcription factors regarding the growth and differentiation of mouse iPS cells in normoxia or hypoxia. Furthermore, we introduce the function of hypoxia-inducible factors (HIFs) in mouse iPS cells in hypoxia using RT-PCR and western blotting together with HIFs knockdown techniques.

  8. Development of rapid, sensitive and non-radioactive tissue-blot diagnostic method for the detection of citrus greening.

    Science.gov (United States)

    Nageswara-Rao, Madhugiri; Miyata, Shin-Ichi; Ghosh, Dilip; Irey, Mike; Garnsey, Stephen M; Gowda, Siddarame

    2013-01-01

    Citrus huanglongbing (HLB or citrus greening) is one of the most devastating diseases of citrus worldwide. The disease is caused by Gram-negative, phloem-limited α-proteobacterium, 'Candidatus Liberibacter asiaticus', vectored by the psyllid, Diaphorina citri Kuwayama. Citrus plants infected by the HLB bacterium may not show visible symptoms sometimes for years following infection and non-uniform distribution within the tree makes the detection of the pathogen very difficult. Efficient management of HLB disease requires rapid and sensitive detection early in the infection followed by eradication of the source of pathogen and the vector. The polymerase chain reaction (PCR) based method is most commonly employed for screening the infected/suspected HLB plants and psyllids. This is time consuming, cumbersome and not practical for screening large number of samples in the field. To overcome this, we developed a simple, sensitive, non-radioactive, tissue-blot diagnostic method for early detection and screening of HLB disease. Digoxigenin labeled molecular probes specific to 'Ca. L. asiaticus' nucleotide sequences have been developed and used for the detection of the pathogen of the HLB disease. The copy number of the target genes was also assessed using real-time PCR experiments and the optimized real-time PCR protocol allowed positive 'Ca. L. asiaticus' detection in citrus samples infected with 'Ca. L. asiaticus' bacterium.

  9. Western blotting using Strongyloides ratti antigen for the detection of IgG antibodies as confirmatory test in human strongyloidiasis

    Directory of Open Access Journals (Sweden)

    Luciana Pereira Silva

    2003-07-01

    Full Text Available The present study was conducted to evaluate the frequency of antigenic components recognized by serum IgG antibodies in Western blotting (WB using a Strongyloides ratti larval extract for the diagnosis of human strongyloidiasis. In addition, the WB results were compared to the enzyme-linked immunosorbent assay (ELISA and the indirect immunofluorescence antibody test (IFAT results. Serum samples of 180 individuals were analyzed (80 with strongyloidiasis, 60 with other intestinal parasitoses, and 40 healthy individuals. S. ratti was obtained from fecal culture of experimentally infected Rattus rattus. For IFAT, S. ratti larvae were used as antigen and S. ratti larval antigenic extracts were employed in WB and ELISA. Eleven S. ratti antigenic components were predominantly recognized by IgG antibodies in sera of patients with strongyloidiasis. There was a positive concordance for the three tests in 87.5% of the cases of strongyloidiasis. The negative concordance in the three tests was 94% and 97.5%, in patients with other intestinal parasitoses and healthy individuals, respectively. In cases of positive ELISA and negative IFAT results, diagnosis could be confirmed by WB. ELISA, IFAT, and WB using S. ratti antigens showed a high rate of sensitivity and specificity. In conclusion, WB using S. ratti larval extract was able to recognize 11 immunodominant antigenic components, showing to be a useful tool to define the diagnosis in cases of equivocal serology.

  10. A novel methylation PCR that offers standardized determination of FMR1 methylation and CGG repeat length without southern blot analysis.

    Science.gov (United States)

    Grasso, Marina; Boon, Elles M J; Filipovic-Sadic, Stela; van Bunderen, Patrick A; Gennaro, Elena; Cao, Ru; Latham, Gary J; Hadd, Andrew G; Coviello, Domenico A

    2014-01-01

    Fragile X syndrome and associated disorders are characterized by the number of CGG repeats and methylation status of the FMR1 gene for which Southern blot (SB) historically has been required for analysis. This study describes a simple PCR-only workflow (mPCR) to replace SB analysis, that incorporates novel procedural controls, treatment of the DNA in separate control and methylation-sensitive restriction endonuclease reactions, amplification with labeled primers, and two-color amplicon sizing by capillary electrophoresis. mPCR was evaluated in two independent laboratories with 76 residual clinical samples that represented typical and challenging fragile X alleles in both males and females. mPCR enabled superior size resolution and analytical sensitivity for size and methylation mosaicism compared to SB. Full mutation mosaicism was detected down to 1% in a background of 99% normal allele with 50- to 100-fold less DNA than required for SB. A low level of full mutation mosaicism in one sample was detected using mPCR but not observed using SB. Overall, the sensitivity for detection of full mutation alleles was 100% (95% CI: 89%-100%) with an accuracy of 99% (95% CI: 93%-100%). mPCR analysis of DNA from individuals with Klinefelter and Turner syndromes, and DNA from sperm and blood, were consistent with SB. As such, mPCR enables accurate, sensitive, and standardized methods of FMR1 analysis that can harmonize results across different laboratories.

  11. Evaluation of western blotting for the diagnosis of enzootic bovine leukemia Avaliação da técnica de western blot no diagnóstico da leucose enzoótica bovina

    Directory of Open Access Journals (Sweden)

    E.T. Gonzalez

    1999-08-01

    Full Text Available A western blotting (WB procedure has been developed for detecting antibodies to bovine leukosis virus (BLV in cattle sera. Two hundred and thirty three serum samples from naturally infected cattle with BLV virus and serial bleedings from experimentally BLV infected cows were used. An agar gel immunodiffusion test (AGID was used for comparing with the results obtained by WB. The AGID positive sera showed a different degree of reactivity by WB test against the two most important viral antigens (gp51 and p24, or against one of them. Other proteins (gp30, p15, p12 and p10 were not detected with any AGID positive sera, being observed occasionally three bands corresponding to the p24 protein. Using sera obtained by BLV experimental inoculation, the antibodies directed to p24 appeared early (between the 2nd and 4th week post inoculation and thereafter antibodies to gp51were detected in some animals. The analysis of field serum samples by AGID as compared to WB showed an agreement of 90.9%. Only 1.7% of sera were negative by AGID and positive by WB and 7.2% that were not conclusive by AGID and were defined by WB (4.2% as positive and 3.0% as negative.Um sistema de western blotting (WB foi desenvolvido para detecção de anticorpos contra o vírus da leucose em soros de bovinos. Foram utilizadas amostras de soros de 233 animais naturalmente infectados e soros de vacas experimentalmente infectadas. O teste de imunodifusão em ágar (AGID foi usado para comparação dos resultados. Graus diferentes de reatividade foram observados em soros positivos ao AGID, quando testados em WB frente a um ou aos dois antígenos mais importantes (gp51 e p24. Outras proteínas (gp30, p15, p12 e p10 não foram detectadas por nenhum soro positivo ao AGID, sendo que três bandas correspondentes à proteína p24 foram observadas ocasionalmente. Em soros obtidos por inoculação experimental, anticorpos contra a proteína p24 foram detectados entre a segunda e a quarta semanas

  12. Detection of mutation in embB gene of Mycobacterium tuberculosis from clinical isolates of tuberculous patients in China by means of reverse-dot blot hybridization

    Institute of Scientific and Technical Information of China (English)

    XUE QIONG WU; YANG LU; JIAN QIN LIANG; JUN XIAN ZHANG; GUANG YU ZHANG; CUI HUAN L(U); HONG MIN LI; BEI CHUAN DING

    2006-01-01

    The relationship between embB mutation of Mycobacterium tuberculosis and ethambutol (EMB) resistance of the clinical isolates of tuberculous patients in China was investigated by reversedot blot hybridization (RDBH) in addition to evaluating the clinical value with application of PCR-RD-BH technique to detect EMB resistance. In the present study, the genotypes of the 258 bp fragments of embB genes from 196 clinical isolates of M. tuberculosis were analysed with RDBH and DNA sequencing. It was demonstrated that 60 out of 91 phenotypically EMB-resistant isolates (65.9%) showed 5 types of missense mutations at codon 306 of embB gene, resulting in the replacement of the Met residue of the wild type strain with Val, Ile or Leu residues. In these mutations, the GTP mutation (38/91,41.8% ) and the ATA mutation ( 16/91, 17.6% ) were the most encountered genotypes. The embB mutation at codon 306 could also be found in 69 isolates of phenotypically EMB-sensitive but resistant to other anti-tuberculous drugs, but no such gene mutation could be found in 36 strains of drug-sensitive isolates. Meanwhile, the concordance with the results of DNA sequencing for one wide-type probe and 5 probes for specific mutations was 100%. It was concluded that the EMB-resistance occurring in most M. tuberculosis is due to appearance of embB mutation at codon 306, and the PCR-RDBH assay was proved to be a rapid, simple and reliable method for the detection of gene mutations, which might be a good alternative for the drug-resistance screening.

  13. A Population-Based Comparative Effectiveness Study of Radiation Therapy Techniques in Stage III Non-Small Cell Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Jeremy P. [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Murphy, James D. [Department of Radiation Medicine and Applied Science, University of California– San Diego, Moores Cancer Center, La Jolla, California (United States); Hanlon, Alexandra L. [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); University of Pennsylvania School of Nursing, Philadelphia, Pennsylvania (United States); Le, Quynh-Thu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California (United States); Loo, Billy W., E-mail: BWLoo@Stanford.edu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California (United States); Diehn, Maximilian, E-mail: diehn@Stanford.edu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California (United States); Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California (United States)

    2014-03-15

    Purpose: Concerns have been raised about the potential for worse treatment outcomes because of dosimetric inaccuracies related to tumor motion and increased toxicity caused by the spread of low-dose radiation to normal tissues in patients with locally advanced non-small cell lung cancer (NSCLC) treated with intensity modulated radiation therapy (IMRT). We therefore performed a population-based comparative effectiveness analysis of IMRT, conventional 3-dimensional conformal radiation therapy (3D-CRT), and 2-dimensional radiation therapy (2D-RT) in stage III NSCLC. Methods and Materials: We used the Surveillance, Epidemiology, and End Results (SEER)-Medicare database to identify a cohort of patients diagnosed with stage III NSCLC from 2002 to 2009 treated with IMRT, 3D-CRT, or 2D-RT. Using Cox regression and propensity score matching, we compared survival and toxicities of these treatments. Results: The proportion of patients treated with IMRT increased from 2% in 2002 to 25% in 2009, and the use of 2D-RT decreased from 32% to 3%. In univariate analysis, IMRT was associated with improved overall survival (OS) (hazard ratio [HR] 0.90, P=.02) and cancer-specific survival (CSS) (HR 0.89, P=.02). After controlling for confounders, IMRT was associated with similar OS (HR 0.94, P=.23) and CSS (HR 0.94, P=.28) compared with 3D-CRT. Both techniques had superior OS compared with 2D-RT. IMRT was associated with similar toxicity risks on multivariate analysis compared with 3D-CRT. Propensity score matched model results were similar to those from adjusted models. Conclusions: In this population-based analysis, IMRT for stage III NSCLC was associated with similar OS and CSS and maintained similar toxicity risks compared with 3D-CRT.

  14. A simple method of fast extracellular solution exchange for the study of whole-cell or single channel currents using patch-clamp technique.

    Science.gov (United States)

    Hering, S; Beech, D J; Bolton, T B

    1987-10-01

    A new concentration-jump technique was devised for the rapid application of drugs to single, isolated cells attached to the base of the experimental chamber while recording from them with patch-clamp technique. Cells were placed in a micro-drop (less than 0.1 microliter) in a small inner bath which was separated from an outer bath by a ring of "Sylgard" polymer. Stable whole-cell recordings were made in the micro-drop and rapid solution exchange took place when a much larger volume of test solution from the outer bath was flooded over the Sylgard ring and mixed with the micro-drop. Complete equilibration occurred within less than 10 ms.

  15. Evaluation of ELISA coupled with Western blot as a surveillance tool for Trichinella infection in wild boar (Sus scrofa).

    Science.gov (United States)

    Cuttell, Leigh; Gómez-Morales, Maria Angeles; Cookson, Beth; Adams, Peter J; Reid, Simon A; Vanderlinde, Paul B; Jackson, Louise A; Gray, C; Traub, Rebecca J

    2014-01-31

    Trichinella surveillance in wildlife relies on muscle digestion of large samples which are logistically difficult to store and transport in remote and tropical regions as well as labour-intensive to process. Serological methods such as enzyme-linked immunosorbent assays (ELISAs) offer rapid, cost-effective alternatives for surveillance but should be paired with additional tests because of the high false-positive rates encountered in wildlife. We investigated the utility of ELISAs coupled with Western blot (WB) in providing evidence of Trichinella exposure or infection in wild boar. Serum samples were collected from 673 wild boar from a high- and low-risk region for Trichinella introduction within mainland Australia, which is considered Trichinella-free. Sera were examined using both an 'in-house' and a commercially available indirect-ELISA that used excretory-secretory (E/S) antigens. Cut-off values for positive results were determined using sera from the low-risk population. All wild boar from the high-risk region (352) and 139/321 (43.3%) of the wild boar from the low-risk region were tested by artificial digestion. Testing by Western blot using E/S antigens, and a Trichinella-specific real-time PCR was also carried out on all ELISA-positive samples. The two ELISAs correctly classified all positive controls as well as one naturally infected wild boar from Gabba Island in the Torres Strait. In both the high- and low-risk populations, the ELISA results showed substantial agreement (k-value=0.66) that increased to very good (k-value=0.82) when WB-positive only samples were compared. The results of testing sera collected from the Australian mainland showed the Trichinella seroprevalence was 3.5% (95% C.I. 0.0-8.0) and 2.3% (95% C.I. 0.0-5.6) using the in-house and commercial ELISA coupled with WB respectively. These estimates were significantly higher (PTrichinella DNA in any mainland animals, but did reveal the presence of a second larvae-positive wild boar on Gabba

  16. Mechanisms of Chemoresistance in Breast Cancer Cells

    Science.gov (United States)

    2005-05-01

    effect on ji-acn f. ........ :.. expression levels of P3-actin. Whether chemical lowering of MDRI expression affects cellular RT-PCR Wester blot ...AdrR/asGCS cells compared with MCF-7-AdrR cells. We confirmed this by Western blot . Whereas, MCF-7-AdrR cells contained characteristically elevated...Research P-glycoprotein expression can be down-regulated by GCS antisense nitrocellulose blot was blocked with 5% fat-free milk powder in PBS

  17. Detection of Babesia and Theileria species infection in cattle from Portugal using a reverse line blotting method.

    Science.gov (United States)

    Silva, M G; Marques, P X; Oliva, A

    2010-12-15

    Babesiosis and Theileriosis are tick-borne diseases widespread in tropical and sub-tropical regions with high economic impact worldwide. In Portugal there are at least 4 tick vectors known to be competent for the transmission of Babesia and Theileria sp. identified: Rhipicephalus bursa, Rhipicephalus (Boophilus) annulatus, Ixodes ricinus and Haemaphysalis punctata. All these potential Babesia and Theileria tick vectors are widely distributed in Portugal, although they are predominant in the Southern region. In this study, 1104 cattle blood samples were randomly collected from Central and Southern regions of Portugal and analyzed by PCR-reverse line blotting (RLB) for the detection of Babesia and Theileria sp. Testing indicated that 74.7% of the bovines tested were positive for either Babesia and/or Theileria sp. In addition, five different apicomplexan species, namely, Theileria buffeli, Theileria annulata, Babesia divergens, Babesia bovis, and Babesia bigemina were detected by RLB among the bovines tested. T. buffeli was the most frequently found species, being present in 69.9% of the positive samples either as single infections (52.4%), or as mixed infections (17.5%). The Babesia specie most frequently found was B. divergens, detected in 4.2% of the infected bovines. Overall, infected bovines were found in all regions tested; however the highest number of infected bovines was observed in Évora district (96.2%) and in cattle from Limousin breeds (81.7%). The results indicate widespread Babesia and Theileria infections in Portuguese bovines, suggesting the need for improved control of ticks and tick-borne diseases.

  18. Estrogen receptors alpha and beta in rat placenta: detection by RT-PCR, real time PCR and Western blotting

    Directory of Open Access Journals (Sweden)

    Al-Bader Maie D

    2006-03-01

    Full Text Available Abstract Background High levels of estrogens during pregnancy not only retard placental and fetal growth but can lead to reproductive tract abnormalities in male progeny. Estrogens act through estrogen receptors (ER to modulate the transcription of target genes. These ER exist in two isoforms, ER alpha and ER beta and recently several variants of these isoforms have been identified. Methods The expressions of ER isoforms and variants have been studied in rat placenta at 16, 19 and 21 days gestation (dg. Gene expression was assessed using RT-PCR and real time PCR while protein expression was studied using Western blotting followed by immunodetection. Placental homogenates were probed with: a monoclonal antibody raised against the steroid binding domain of the ER alpha (ER alpha -S, a monoclonal antibody raised against the hinge region of ER alpha (ER alpha -H and a polyclonal antibody raised against the amino terminus of ER beta. Results ER alpha and ER beta mRNA and protein were detected from as early as 16 dg. Two PCR products were detected for ER alpha, one for the wild type ER alpha, and a smaller variant. Real time PCR results suggested the presence of a single product for ER beta. The antibodies used for detection of ER alpha protein both identified a single 67 kDa isoform; however a second 54 kDa band, which may be an ER alpha variant, was identified when using the ER alpha -H antibody. The abundance of both ER alpha bands decreased significantly between 16 and 19 dg. As for ER beta, four bands (76, 59, 54 and 41 kDa were detected. The abundance of the 59 and 54 kDa bands decreased significantly between 16 and 19 dg. Conclusion This study shows that both ER protein isoforms and their variants are present in rat placenta. The decrease in their expression near parturition suggests that the placenta may be relatively unresponsive to estrogens at this stage.

  19. Comparative evaluation of eosinophils in normal mucosa, dysplastic mucosa and oral squamous cell carcinoma with hematoxylin-eosin, Congo red, and EMR1 immunohistochemical staining techniques

    Science.gov (United States)

    kargahi, Neda; Razavi, Sayyed Mohammad; Deyhimi, Parviz; Homayouni, Solmaz

    2015-01-01

    Background: Oral squamous cell carcinoma is the most common malignant lesion of the oral cavity, and it involves various molecular mechanisms. The development of oral squamous cell carcinoma is influenced by the host immune cells, such as eosinophils. The present study was conducted to compare the presence of eosinophils in normal mucosa, dysplastic mucosa, and oral squamous cell carcinoma by -hematoxylin- eosin staining, Congo red staining, and epidermal growth factor-like (EGF-like) module containing a mucin–like hormone receptor1 (EMR1) immunohistochemical marker. Methods: In this cross-sectional study, 60 paraffinized samples were selected, consisting of 20 normal mucosae, 20 dysplastic mucosae, and 20 squamous cell carcinoma samples. After confirmation of the diagnosis, the mean number of eosinophils was evaluated by hematoxylin-eosin, Congo red, and immunohystochemical staining techniques. The data were analyzed by SPSS-10 software using the Kruskal-Wallis and Friedman tests. Results: The results showed that the number of eosinophils in dysplastic mucosa was significantly higher than the number in normal mucosa, and the number of eosinophils in squamous cell carcinoma was significantly higher than the number in dysplastic mucosa in all staining techniques (p<0.001). Moreover, the comparison of staining techniques showed a significantly higher number of eosinophils in EMR1immunohistochemicalmarker than were observed when Congo red and hematoxylin - eosin (H&E) staining techniques were used (p<0.001). Conclusion: It can be argued that eosinophil contributes to the identification of lesions that have a higher potential of malignant transformation. Moreover, eosinophil can be suggested as an indicator in the differentiation of oral lesions in cases with borderline diagnosis and in targeted molecular therapy. PMID:26120409

  20. Cell-surface changes in cadmium-resistant Euglena: Studies using lectin-binding techniques and flow cytometry

    Energy Technology Data Exchange (ETDEWEB)

    Bonaly, J.; Brochiero, E. [Faculte de Pharmacie, Chatenay-Malabry (France)

    1994-01-01

    Most in vitro studies on contaminants focus on the short-term effects of pollutants on cells, without regard to long-term effects and the ability of cells or microorganisms to develop a specific resistance to a pollutant. Cadmium is ubiquitous environmental contaminant. This heavy metal enters the aquatic environment mainly through vapor emissions and fallout during smelting operations. Diverse mechanisms of algal resistance to toxic metals are known. Among these, the most general mechanism is the development of metal-binding proteins. In cadmium-resistant unicellular Euglena gracilis Z algae cells, the metal did not appear to be sequestered on soluble metal-binding ligands. Previous experiments have shown that resistance development is related to a diminution of cadmium penetration into cells, implicating cell surface or membrane alteration. This research investigates the mechanisms of development of cadmium resistance in Euglena cells at the cell-surface level. Sugar chains of glycoproteins and glycolipids are a predominant feature of the surface of cells. Moreover, the cell-response to environmental changes is often orchestrated through surface macromolecules such as glycoproteins. In this study, we applied this lectin method to investigate surface carbohydrate expression during and after resistance development. Our interest was twofold: (1) to learn more about the carbohydrate composition of the cell-surface of Euglena; and (2) to determine whether transition from wild cells to Cd-resistant cells changes the expression of cell-surface carbohydrates. 13 refs., 2 figs., 1 tab.

  1. Application of process quality engineering techniques to improve the understanding of the in vitro processing of stem cells for therapeutic use.

    Science.gov (United States)

    Thomas, R J; Hourd, P C; Williams, D J

    2008-09-10

    The translation of experimental cell-based therapies to volume produced commercially successful clinical products requires the development of capable, economic, scaleable (and therefore frequently necessarily automated) manufacturing processes. Application of proven quality engineering techniques will be required to interrogate, optimise, and control in vitro cell culture processes to regulatory and clinically acceptable specifications. We have used a Six Sigma inspired quality engineering approach to design and conduct a factorial screening experiment to investigate the expansion process of a population of primary bone marrow-derived human mesenchymal stem cells on a scaleable automated cell culture platform. Key cell culture process inputs (seeding density, serum concentration, media quantity and incubation time) and important cell culture process responses (cell number and the expression of alkaline phosphatase, STRO-1, CD105 and CD71) were identified as experimental variables. The results rank the culture factors and significant culture factor interactions by the magnitude of their effect on each of the process responses. This level of information is not available from conventional single factor cell culture studies but is essential to efficiently identify sources of variation and foci for further process optimisation. Systematic quality engineering approaches such as those described here will be essential for the design of regulated cell therapy manufacturing processes because of their focus on identifying the sources of and the control of variation, an issue that is at the core of current Good Manufacturing Practice.

  2. Selenium Metabolism in Cancer Cells: The Combined Application of XAS and XFM Techniques to the Problem of Selenium Speciation in Biological Systems

    Directory of Open Access Journals (Sweden)

    Hugh H. Harris

    2013-05-01

    Full Text Available Determining the speciation of selenium in vivo is crucial to understanding the biological activity of this essential element, which is a popular dietary supplement due to its anti-cancer properties. Hyphenated techniques that combine separation and detection methods are traditionally and effectively used in selenium speciation analysis, but require extensive sample preparation that may affect speciation. Synchrotron-based X-ray absorption and fluorescence techniques offer an alternative approach to selenium speciation analysis that requires minimal sample preparation. We present a brief summary of some key HPLC-ICP-MS and ESI-MS/MS studies of the speciation of selenium in cells and rat tissues. We review the results of a top-down approach to selenium speciation in human lung cancer cells that aims to link the speciation and distribution of selenium to its biological activity using a combination of X-ray absorption spectroscopy (XAS and X-ray fluorescence microscopy (XFM. The results of this approach highlight the distinct fates of selenomethionine, methylselenocysteine and selenite in terms of their speciation and distribution within cells: organic selenium metabolites were widely distributed throughout the cells, whereas inorganic selenium metabolites were compartmentalized and associated with copper. New data from the XFM mapping of electrophoretically-separated cell lysates show the distribution of selenium in the proteins of selenomethionine-treated cells. Future applications of this top-down approach are discussed.

  3. Selenium metabolism in cancer cells: the combined application of XAS and XFM techniques to the problem of selenium speciation in biological systems.

    Science.gov (United States)

    Weekley, Claire M; Aitken, Jade B; Finney, Lydia; Vogt, Stefan; Witting, Paul K; Harris, Hugh H

    2013-05-21

    Determining the speciation of selenium in vivo is crucial to understanding the biological activity of this essential element, which is a popular dietary supplement due to its anti-cancer properties. Hyphenated techniques that combine separation and detection methods are traditionally and effectively used in selenium speciation analysis, but require extensive sample preparation that may affect speciation. Synchrotron-based X-ray absorption and fluorescence techniques offer an alternative approach to selenium speciation analysis that requires minimal sample preparation. We present a brief summary of some key HPLC-ICP-MS and ESI-MS/MS studies of the speciation of selenium in cells and rat tissues. We review the results of a top-down approach to selenium speciation in human lung cancer cells that aims to link the speciation and distribution of selenium to its biological activity using a combination of X-ray absorption spectroscopy (XAS) and X-ray fluorescence microscopy (XFM). The results of this approach highlight the distinct fates of selenomethionine, methylselenocysteine and selenite in terms of their speciation and distribution within cells: organic selenium metabolites were widely distributed throughout the cells, whereas inorganic selenium metabolites were compartmentalized and associated with copper. New data from the XFM mapping of electrophoretically-separated cell lysates show the distribution of selenium in the proteins of selenomethionine-treated cells. Future applications of this top-down approach are discussed.

  4. A novel technique for guided bone regeneration using platelet-rich plasma and osteogenic progenitor cells: Literature-based rationale and case report.

    Science.gov (United States)

    Kwon, TaeHyun; Grieco, Peter C; Levin, Liran; Intini, Giuseppe

    2016-03-01

    Achieving predictable guided bone regeneration in critical size defects for future endosseous dental implant therapy poses a great challenge to clinicians. A novel technique utilizing autogenous osteogenic progenitor cells, calcium sulfate activated platelet-rich plasma in addition to particulate allograft was successfully used to augment a severely deficient maxillary anterior edentulous ridge. After 6 months of healing, satisfactory radiographic and clinical bone gain was noted with significant increase in alveolar ridge width. Endosseous implants were placed and restored successfully. The techniques with underlying clinical and biologic rationales are presented and discussed in this report.

  5. Relative performance of Organon kit in comparison to Du Pont for confirmatory serological testing of HIV infection by western blot test in sera from blood donors.

    Science.gov (United States)

    Aggarwal, R K; Chatterjee, R; Chattopadhya, D; Kumari, S

    1992-06-01

    A total of 32 specimens with different categories of reactivity by Du Pont Western Blot kit comprising of specimens showing full spectrum of HIV-I antigen specific bands, 19 specimens showing total absence of bands and four specimens showing non-specific bands (without any interpretative importance) were subjected to Western Blot testing by Organon test. Of the nine specimens showing full spectrum of bands by Du Pont the correlation with Organon kit was 100 per cent based on WHO criteria. Four specimens with non-specific indeterminate band pattern by Du Pont failed to show any band in Organon kit, indicating that latter to be more specific.

  6. Adaptation of CHO cells in serum-free conditions for erythropoietin production: Application of EVOP technique for process optimization.

    Science.gov (United States)

    Jukić, Suzana; Bubenik, Dijana; Pavlović, Nediljko; Tušek, Ana Jurinjak; Srček, Višnja Gaurina

    2016-09-01

    Mammalian cell cultures are the preferred expression systems for the production of biopharmaceuticals requiring posttranslational processing. Usually, cell cultures are cultivated in medium supplemented with serum, which supports cell proliferation, viability, and productivity. However, due to scientific and regulatory concerns, serum-free conditions are required in recombinant protein production. Cell lines that are intended for commercial recombinant protein production have to adapt to serum- or protein-free conditions early in their development. This is a labor- and time-consuming process because of the specific cell requirements related to their adaptation in new microenvironment. In the present study, a Chinese hamster ovary (CHO) cell line producing glycosylated recombinant human erythropoietin (rhEPO) was adapted for growth and rhEPO production in serum- and protein-free conditions. The physiology, growth parameters, and morphology of the CHO cells and rhEPO biosynthesis and structure were closely monitored during the adaptation process to avoid unwanted selection of cell subpopulations. The results showed that the CHO cells were successfully adapted to suspension growth and rhEPO production in the protein-free conditions and that the structure of rhEPO remained nearly unchanged. In addition, during rhEPO production in the protein-free suspension conditions, the agitation rate seem to be significant for optimal process performance in contrast to the initial cell concentration, evaluated through evolutionary operation method.

  7. Matrix-assisted laser desorption-ionization mass spectrometry peptide mass fingerprinting for proteome analysis: identification efficiency after on-blot or in-gel digestion with and without desalting procedures.

    Science.gov (United States)

    Lamer, S; Jungblut, P R

    2001-03-10

    In theory, peptide mass fingerprinting by matrix assisted laser desorption-ionization mass spectrometry (MALDI-MS) has the potential to identify all of the proteins detected by silver staining on gels. In practice, if the genome of the organism investigated is completely sequenced, using current techniques, all proteins stained by Coomassie Brilliant Blue can be identified. This loss of identification sensitivity of ten to hundred-fold is caused by loss of peptides by surface contacts. Therefore, we performed digestion and transfer of peptides in the lower microl range and reduced the number of steps. The peptide mix obtained from in-gel or on-blot digestion was analyzed directly after digestion or after concentration on POROS R2 beads. Eight protein spots of a 2-DE gel from Mycobacterium bovis BCG were identified using these four preparation procedures for MALDI-MS. Overall, on-blot digestion was as effective as in-gel digestion. Whereas higher signal intensities resulted after concentration, hydrophilic peptides are better detected by direct measurement of the peptide mix without POROS R2 concentration.

  8. Point-contacting by localised dielectric breakdown: Characterisation of a metallisation technique for the rear surface of a solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Western, Ned J., E-mail: n.western@unsw.edu.au; Perez-Wurfl, Ivan; Wenham, Stuart R.; Bremner, Stephen P. [Photovoltaics Centre of Excellence, UNSW, Sydney NSW 2052 (Australia)

    2015-07-28

    Characterisation results are presented for ohmic contacts to passivated crystalline silicon, formed using the point-contacting by localised dielectric breakdown technique. Self aligned contact is made between the metal and heavily doped surface regions through an intrinsic a-Si:H passivation layer. Local doping is provided by a laser using a standard technique identical to that for selective emitter formation. Our results for gate metals of Au, Al, and Ti show that the technique does not rely on reactivity between the dielectric and the metal, excluding metal induced crystallisation from the contacting process. Diffusion of the gate metal into the dielectric is observed in transmission electron microscope images suggesting high temperatures are present locally during the breakdown process. The technique is equally applicable to contacting of n and p-type silicon, making it a potential alternative for ohmic contacting to silicon to passivated rear surfaces.

  9. Mechanical properties of mammalian single smooth muscle cells. II. Evaluation of a modified technique for attachment of cells to the measurement apparatus

    NARCIS (Netherlands)

    J.J. Glerum (Jacobus); R. van Mastrigt (Ron)

    1990-01-01

    textabstractA method is described for attaching isolated single smooth muscle cells to an apparatus designed for measuring the longitudinal forces developed passively and actively by the cell upon straining, electrical or pharmacological stimulation. Primary attachment of the cell is based on its na

  10. Two-Dimensional Measurement of n+-p Asymmetrical Junctions in Multicrystalline Silicon Solar Cells Using AFM-Based Electrical Techniques with Nanometer Resolution: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, C. S.; Moutinho, H. R.; Li, J. V.; Al-Jassim, M. M.; Heath, J. T.

    2011-07-01

    Lateral inhomogeneities of modern solar cells demand direct electrical imaging with nanometer resolution. We show that atomic force microscopy (AFM)-based electrical techniques provide unique junction characterizations, giving a two-dimensional determination of junction locations. Two AFM-based techniques, scanning capacitance microscopy/spectroscopy (SCM/SCS) and scanning Kelvin probe force microscopy (SKPFM), were significantly improved and applied to the junction characterizations of multicrystalline silicon (mc-Si) cells. The SCS spectra were taken pixel by pixel by precisely controlling the tip positions in the junction area. The spectra reveal distinctive features that depend closely on the position relative to the electrical junction, which allows us to indentify the electrical junction location. In addition, SKPFM directly probes the built-in potential over the junction area modified by the surface band bending, which allows us to deduce the metallurgical junction location by identifying a peak of the electric field. Our results demonstrate resolutions of 10-40 nm, depending on the techniques (SCS or SKPFM). These direct electrical measurements with nanometer resolution and intrinsic two-dimensional capability are well suited for investigating the junction distribution of solar cells with lateral inhomogeneities.

  11. The influence of the laser parameter on the electrical shunt resistance of scribed Cu(InGa)Se{sub 2} solar cells by nested circular laser scribing technique

    Energy Technology Data Exchange (ETDEWEB)

    Wang, X., E-mail: xi.wang@iom-leipzig.de [School of Science, Nanjing University of Science and Technology, Xiaolingwei 200, 210094 Nanjing (China); Leibniz-Institut für Oberflächenmodifizierung e. V., Leipzig 04318, Permoserstr. 15 (Germany); Ehrhardt, M.; Lorenz, P. [Leibniz-Institut für Oberflächenmodifizierung e. V., Leipzig 04318, Permoserstr. 15 (Germany); Scheit, C.; Ragnow, S. [Solarion AG, Ostende 5, 04288 Leipzig (Germany); Ni, X.W. [School of Science, Nanjing University of Science and Technology, Xiaolingwei 200, 210094 Nanjing (China); Zimmer, K., E-mail: klaus.zimmer@iom-leipzig.de [Leibniz-Institut für Oberflächenmodifizierung e. V., Leipzig 04318, Permoserstr. 15 (Germany)

    2014-05-01

    Laser scribing of thin film solar cells attracts increasing attention for performing integrated interconnection. For high efficiency solar modules, low damage laser scribing techniques are needed. The optimization of the laser scribing process concerns all functional properties of the device but in particular the efficiency. The recently demonstrated nested circular scribing technique allows the in-process measurement of the shunt formation due to laser scribing (P3) of the thin film solar cell. By using this technique, the influence of laser fluence and pulse overlap on the electrical shunt resistance formation at laser scribing of Cu(InGa)Se{sub 2} solar cell with ultrashort laser pulses (tp = 10 ps, λ = 1.06 μm, v = 2000 mm/s) was investigated. The TCO layer is removed when the laser fluence is about 0.3 J/cm{sup 2}. The Cu(InGa)Se{sub 2} is removed completely to expose molybdenum when the laser fluence is about 3.5 J/cm{sup 2}. For low defect scribing, a clear tendency of using a low pulse overlap and low laser fluences were found.

  12. Concanavalin A-mediated cell agglutinability induced by Vaccinia virions. [Uv radiation, /sup 125/I tracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Mbuy, G.; Bubel, H.C.

    1978-12-01

    The induction of enhanced concanavalin A (Con A)-mediated cellular agglutinability by purified vaccinia virus was examined quantitatively. Increased HEp-2 cell agglutinability by the lectin occurred within the first hour of infection and persisted without further change throughout the virus infectious cycle. Ultraviolet, but not heat-inactivated, virus was as effective as infectious virus in causing increased Con A agglutinability. Inhibition of viral and host cell protein synthesis by Streptovitacin A failed to alter the lectin response to vaccinia virus infection. Fluorescein-labeled Con A was observed to form clusters and large fluorescent patches on the infected cell surface during the earliest stage of infection. Studies with /sup 125/I-labeled Con A revealed an early but minimal increase in lectin binding to infected cells. After the first hour of infection, no further increase in Con A binding was observed. When cells were exposed to purified vaccinia virus surface tubules increased Con A agglutinability comparable to that obtained with native virus was demonstrated. Con A-mediated agglutinability of cells was temperature-dependent and displayed a higher temperature transition in infected cells. These data suggest that upon contact with the host cell, vaccinia virions or surface tubules induce alterations in the plasma membrane which are reflected in an enhanced agglutinability by Con A.

  13. Analysis of maturation states of rat bone marrow-derived dendritic cells using an improved culture technique.

    Science.gov (United States)

    Grauer, Oliver; Wohlleben, Gisela; Seubert, Silvia; Weishaupt, Andreas; Kämpgen, Eckhart; Gold, Ralf

    2002-04-01

    In this study, we examined in more detail the development of rat bone marrow-derived dendritic cells (BMDC). A two-stage culture system was used to propagate BMDC from rat bone marrow precursors. BMDC developed within clusters of proliferating cells after repetitive addition of rat granulocyte/macrophage colony-stimulating factor and rat interleukin (IL)-4 at a concentration of 5 ng/ml to the cultures. Fluorescence-activated cell sorter analysis performed at an early stage of development (day 6) revealed an immature phenotype with intermediate levels of major histocompatibility complex (MHC) class II expression and low levels of the costimulator molecules CD80 and CD86. Upon further culture, a strong upregulation of MHC class II, costimulatory and adhesion molecules could be observed, whereas macrophage marker antigens were downregulated. Late-stage BMDC (day 10) showed a high expression of MHC class I and II, ICAM-1, Ox62 and CD11c, and revealed a split pattern of B7-1 and B7-2. The cell yield was about 40% of the initially plated bone marrow cells with 80% MHC class II-high and less than 20% MHC class II-low positive cells. Full maturation of rat BMDC (day 12) with an almost uniform expression of B7 was achieved by subsequent subculture and further stimulation with rat tumour necrosis factor alpha (TNF-alpha), lipopolysaccharide (LPS) or soluble CD40 ligand (CD40L). Analysis of the cell supernatant revealed a strong IL-12 production after LPS or CD40L, and to a lesser extent after TNF-alpha stimulation. Additionally, LPS-treated, but not CD40L-treated BMDC secreted TNF-alpha into the supernatant. Early-stage BMDC sufficiently triggered a T cell receptor (TCR) downregulation, but did not stimulate naive T cells in an allogeneic mixed leukocyte reaction (MLR) and revealed a low stimulatory capacity in an antigen-specific T cell assay. In contrast, late-stage BMDC and especially fully mature BMDC strongly induced TCR internalisation, elicited high T cell responses

  14. Experimental techniques; Techniques experimentales

    Energy Technology Data Exchange (ETDEWEB)

    Roussel-Chomaz, P. [GANIL CNRS/IN2P3, CEA/DSM, 14 - Caen (France)

    2007-07-01

    This lecture presents the experimental techniques, developed in the last 10 or 15 years, in order to perform a new class of experiments with exotic nuclei, where the reactions induced by these nuclei allow to get information on their structure. A brief review of the secondary beams production methods will be given, with some examples of facilities in operation or under project. The important developments performed recently on cryogenic targets will be presented. The different detection systems will be reviewed, both the beam detectors before the targets, and the many kind of detectors necessary to detect all outgoing particles after the reaction: magnetic spectrometer for the heavy fragment, detection systems for the target recoil nucleus, {gamma} detectors. Finally, several typical examples of experiments will be detailed, in order to illustrate the use of each detector either alone, or in coincidence with others. (author)

  15. Generation of the SCN1A epilepsy mutation in hiPS cells using the TALEN technique

    Science.gov (United States)

    Chen, Wanjuan; Liu, Jingxin; Zhang, Longmei; Xu, Huijuan; Guo, Xiaogang; Deng, Sihao; Liu, Lipeng; Yu, Daiguan; Chen, Yonglong; Li, Zhiyuan

    2014-06-01

    Human induced pluripotent stem cells (iPSC) can be used to understand the pathological mechanisms of human disease. These cells are a promising source for cell-replacement therapy. However, such studies require genetically defined conditions. Such genetic manipulations can be performed using the novel Transcription Activator-Like Effector Nucleases (TALENs), which generate site-specific double-strand DNA breaks (DSBs) with high efficiency and precision. Combining the TALEN and iPSC methods, we developed two iPS cell lines by generating the point mutation A5768G in the SCN1A gene, which encodes the voltage-gated sodium channel Nav1.1 α subunit. The engineered iPSC maintained pluripotency and successfully differentiated into neurons with normal functional characteristics. The two cell lines differ exclusively at the epilepsy-susceptibility variant. The ability to robustly introduce disease-causing point mutations in normal hiPS cell lines can be used to generate a human cell model for studying epileptic mechanisms and for drug screening.

  16. Explant culture: a simple, reproducible, efficient and economic technique for isolation of mesenchymal stromal cells from human adipose tissue and lipoaspirate.

    Science.gov (United States)

    Priya, Nancy; Sarcar, Shilpita; Majumdar, Anish Sen; SundarRaj, Swathi

    2014-09-01

    Adipose tissue has emerged as a preferred source of mesenchymal stem/stromal cells (MSC), due to its easy accessibility and high MSC content. The conventional method of isolation of adipose tissue-derived stromal cells (ASC) involves enzymatic digestion and centrifugation, which is a costly and time-consuming process. Mechanical stress during isolation, use of bacterial-derived products and potential contamination with endotoxins and xenoantigens are other disadvantages of this method. In this study, we propose explant culture as a simple and efficient process to isolate ASC from human adipose tissue. This technique can be used to reproducibly isolate ASC from fat tissue obtained by liposuction as well as surgical resection, and yields an enriched ASC population free from contaminating haematopoietic cells. We show that explanting adipose tissue results in a substantially higher yield of ASC at P0 per gram of initial fat tissue processed, as compared to that obtained by enzymatic digestion. We demonstrate that ASC isolated by explant culture are phenotypically and functionally equivalent to those obtained by enzymatic digestion. Further, the explant-derived ASC share the immune privileged status and immunosuppressive properties implicit to MSC, suggesting that they are competent to be tested and applied in allogeneic clinical settings. As explant culture is a simple, inexpensive and gentle method, it may be preferred over the enzymatic technique for obtaining adipose tissue-derived stem/stromal cells for tissue engineering and regenerative medicine, especially in cases of limited starting material.

  17. [application of the analytical transmission electron microscopy techniques for detection, identification and visualization of localization of nanoparticles of titanium and cerium oxides in mammalian cells].

    Science.gov (United States)

    Shebanova, A S; Bogdanov, A G; Ismagulova, T T; Feofanov, A V; Semenyuk, P I; Muronets, V I; Erokhina, M V; Onishchenko, G E; Kirpichnikov, M P; Shaitan, K V

    2014-01-01

    This work represents the results of the study on applicability of the modern methods of analytical transmission electron microscopy for detection, identification and visualization of localization of nanoparticles of titanium and cerium oxides in A549 cell, human lung adenocarcinoma cell line. A comparative analysis of images of the nanoparticles in the cells obtained in the bright field mode of transmission electron microscopy, under dark-field scanning transmission electron microscopy and high-angle annular dark field scanning transmission electron was performed. For identification of nanoparticles in the cells the analytical techniques, energy-dispersive X-ray spectroscopy and electron energy loss spectroscopy, were compared when used in the mode of obtaining energy spectrum from different particles and element mapping. It was shown that the method for electron tomography is applicable to confirm that nanoparticles are localized in the sample but not coated by contamination. The possibilities and fields of utilizing different techniques for analytical transmission electron microscopy for detection, visualization and identification of nanoparticles in the biological samples are discussed.

  18. Cell adhesion properties of patterned poly(acrylic acid)/poly(allylamine hydrochloride) multilayer films created by room-temperature imprinting technique.

    Science.gov (United States)

    Lu, Yingxi; Sun, Junqi; Shen, Jiacong

    2008-08-05

    Patterned poly(acrylic acid) (PAA)/poly(allylamine hydrochloride) (PAH) multilayer films with line structures of different lateral size and vertical height were fabricated by a room-temperature imprinting technique, and their cell adhesion properties were investigated. The nonimprinted PAA/PAH multilayer films are cytophilic toward NIH/3T3 fibroblasts and HeLa cells whether PAA or PAH is the outer most layer. In contrast, the PAA/PAH multilayer films with a 6.5-microm-line/3.5-microm-space pattern structure are cytophobic toward NIH/3T3 fibroblasts and HeLa cells when the height of the lines is 1.29 microm. By either increasing the lateral size of the patters to 69-microm-line/43-mum-space or decreasing the height of the imprinted lines to approximately 107 nm, imprinted PAA/PAH multilayer films become cytophilic. This kind of transition of cell adhesion behavior derives from the change of the physical pattern size of the PAA/PAH multilayer films and is independent of the chemical composition of the films. The easy patterning of layer-by-layer assembled polymeric multilayer films with the room-temperature imprinting technique provides a facile way to tailor the cellular behavior of the layered polymeric films by simply changing the pattern dimensions.

  19. Optical and Acoustical Techniques for Non-viral Gene Delivery to Mammalian Cells and In-situ Study of Cytoskeletal Mechanics

    Science.gov (United States)

    Ma, Zili

    Since the first optical microscope invented by Anton van Leeuwenhoek in 1674, the great development of laser technique and its applications in biophotonics have helped us reveal the mechanisms underlying numerous biological activities gradually. The introduction of fs lasers to the studies of biology has emerged as a fast developing area calling for the efforts and skills both from optics and electric engineering and biology and medicine. Due to the fast update of laser source techniques, there has been an increasing number of commercialized fs lasers available for this growing market of biophotonics. To better utilize the potential offered by fs lasers, we studied the technique of optical gene delivery and tried to narrow the gap between laboratorial research and industrial/clinical applications, in that the strict experimental conditions of specific optical laboratorial studies are generally not appropriate for the practical biological applications. To carry out our experiments, we built a two-stage amplifier fs laser system to generate the desired pulse train. The laser pulse train was coupled into an invert fluorescence microscope for the imaging and manipulation of each cell. To overcome limitations brought by the tight focus of laser beam due to high NA objective, we introduced gold nanorods (GNRs), a metallic nanomaterial, with tunable optical property. With these additional membrane for membrane permeabilization, which could significantly improve the manipulation speed than that based on the tightly focused laser. We used GFP plasmid to demonstrate the applications of this technique in gene delivery, and successfully transfected and GFP-expressed cells were observed one day after the optical transfection. Additionally, as an important trend of biophotonics, the integration of optics with microfluidic chips has become the new frontier of both biology and engineering. Here we firstly demonstrated a technique of gene delivery by an on-chip device generating

  20. Comparison of cervical cell morphology using two different cytology techniques for early detection of pre-cancerous lesions.

    Science.gov (United States)

    Moosa, Najla Yussuf; Khattak, Nuzhat; Alam, Muhammad Irfan; Sher, Alam; Shah, Walayat; Mobashar, Shumaila; Alam, Muhammad Imran; Javid, Asima

    2014-01-01

    Cervical cancer is an issue of foremost importance globally, specifically affecting the developing nations. Significant advances have taken place with regard to diagnosis of cervical cancer, especially with screening. Appropriate screening measures can thus reduce the incidence of cervical cancer. The most desirable screening technique should be less invasive, easy to perform, cost-effective and cover a wide range of diagnostic icons. Manual liquid based cytology (MLBC) can be considered as one of the suitable technique for screening with the above-mentioned benefits. The aim of the current study was to compare two cervical screening techniques on the basis of different morphological parameters and staining parameters by using modified acetic acid Pap staining to see the possibility of reducing time economy involved in conventional Pap staining (CPS). The study was conducted on a total 88 cases and all were analyzed with both MLBC and CPS. Forty eight cases that were regarded as satisfactory on the basis of Bethesda system by both methods were further recruited for investigation. Their morphological parameters and staining quality were compared and scored according to a scoring system defined in the study. Quality indices was calculated for both staining procedures and smear techniques.

  1. Effects of CdTe growth conditions and techniques on the efficiency limiting defects and mechanisms in CdTe solar cells

    Science.gov (United States)

    Rohatgi, A.; Chou, H. C.; Jokerst, N. M.; Thomas, E. W.; Ferekides, C.; Kamra, S.; Feng, Z. C.; Dugan, K. M.

    1996-01-01

    CdTe solar cells were fabricated by depositing CdTe films on CdS/SnO2/glass substrates using close-spaced sublimation (CSS) and metalorganic chemical vapor deposition (MOCVD). Te/Cd mole ratio was varied in the range of 0.02 to 6 in the MOCVD growth ambient in an attempt to vary the native defect concentration. Polycrystalline CdTe layers grown by MOCVD and CSS both showed average grain size of about 2 μm. However, the CdTe films grown by CSS were found to be less faceted and more dense compared to the CdTe grown by MOCVD. CdTe growth techniques and conditions had a significant impact on the electrical characteristics of the cells. The CdTe solar cells grown by MOCVD in the Te-rich growth condition and by the CSS technique gave high cell efficiencies of 11.5% and 12.4%, respectively, compared to 6.6% efficient MOCVD cells grown in Cd-rich conditions. This large difference in efficiency is explained on the basis of (a) XRD measurements which showed a higher degree of atomic interdiffusion at the CdS/CdTe interface in high performance devices, (b) Raman measurements which endorsed more uniform and preferred grain orientation by revealing a sharp CdTe TO mode in the high efficiency cells, and (c) carrier transport mechanism which switched from tunneling/interface recombination to depletion region recombination in the high efficiency cells. In this study, Cu/Au layers were evaporated on CdTe for the back contact. Lower efficiency of the Te-rich MOCVD cells, compared to the CSS cells, was attributed to contact related additional loss mechanisms, such as Cd pile-up near Cu/CdTe interface which can give rise to Cd-vacancy defects in the bulk, and higher Cu concentration in the CdTe layer which can cause shunts in the device. Finally, SIMS measurements on the CdTe films of different crystallinity and grain size confirmed that grain boundaries are the main conduits for Cu migration into the CdTe film. Thus larger CdTe grain size or lower grain boundary area per unit volume

  2. A lipidomics investigation of the induced hypoxia stress on HeLa cells by using MS and NMR techniques.

    Science.gov (United States)

    Yu, Yang; Vidalino, Laura; Anesi, Andrea; Macchi, Paolo; Guella, Graziano

    2014-04-01

    Induced hypoxia stress on cervical cancer derived cells (HeLa cells) leads to significant changes in their membrane lipid profiles. The lipidome of HeLa cells was characterized by a joint approach wherein liquid chromatography-mass spectrometry (LC-MS) analysis was followed by high resolution NMR measurements. Multivariate data analysis showed apparent separation between control and hypoxia-treated HeLa cells and thus demonstrated hypoxia effects on lipid metabolism. The most striking finding was that hypoxia stimulation significantly reduced the total amount of cellular phosphoinositols (PI) but caused a prominent increase in the amount of lyso phosphocholines (lyso-PC) and lyso phosphoethanolamines (lyso-PE). The observed decrease of PI amount under hypoxic conditions is probably due to the accumulation of cellular myo-inositol, which is known to play a critical role in de novo synthesis of PI. Moreover, our study suggests that polyunsaturated phospholipid species are stronger biomarkers for discriminating the effect of hypoxia treatment. The evaluation of changes in the average unsaturation index (UI) of the membrane lipids acyl chains reveals that UI slightly increases in several lipid classes, thus affecting membrane fluidity and further membrane-dependent functions. The plausible mechanisms by which HeLa cells adapt to hypoxia conditions are also briefly reported.

  3. Assembly of cell-laden hydrogel fiber into non-liquefied and liquefied 3D spiral constructs by perfusion-based layer-by-layer technique.

    Science.gov (United States)

    Sher, Praveen; Oliveira, Sara M; Borges, João; Mano, João F

    2015-01-06

    In this work, three-dimensional (3D) self-sustaining, spiral-shaped constructs were produced through a combination of ionotropic gelation, to form cell-encapsulated alginate fibers, and a perfusion-based layer-by-layer (LbL) technique. Single fibers were assembled over cylindrical molds by reeling to form spiral shapes, both having different geometries and sizes. An uninterrupted nanometric multilayer coating produced by a perfusion-based LbL technique, using alginate and chitosan, generated stable 3D spiral-shaped macrostructures by gripping and affixing the threads together without using any crosslinking/binding agent. The chelation process altered the internal microenvironment of the 3D construct from the solid to the liquefied state while preserving the external geometry. L929 cell viability by MTS and dsDNA quantification favor liquefied 3D constructs more than non-liquefied ones. The proposed technique setup helps us to generate complex polyelectrolyte-based 3D constructs for tissue engineering applications and organ printing.

  4. Modified technique of using conventional slider boat for liquid phase epitaxy of silicon for solar cell application

    Indian Academy of Sciences (India)

    D Majumdar; S Chatterjee; U Gangopadhyay; H Saha

    2003-10-01

    Epitaxial layers of silicon are grown on single crystal Si-substrate from a solution of silicon in indium using conventional graphite slider boat technique. The important problems of natural convection due to lower density of silicon compared to indium, poor wetting of substrate due to high angle of contact of indium solution on silicon substrate resulting in poor nucleation, melt removal from the growth substrate and saturation wafer associated with LPE in this technique are practically eliminated using sandwich method with simple modifications of the boat and the method of growth. Some experimental studies on the effect of different surface preparations of growth substrate are also reported. Growth results are shown and discussed. Further, improvization of slider boat to facilitate better study of growth parameters is suggested in the line of modification already carried out.

  5. On-line preferential solvation studies of polymers by coupled chromatographic-Fourier transform infrared spectroscopic flow-cell technique.

    Science.gov (United States)

    Malanin, M; Eichhorn, K-J; Lederer, A; Treppe, P; Adam, G; Fischer, D; Voigt, D

    2009-12-18

    Qualitative and quantitative comparison between liquid chromatography (LC) and LC coupled with Fourier transform infrared spectroscopy (LC-FTIR) to evaluate preferential solvation phenomenon of polymers in a mixed solvent has been performed. These studies show that LC-FTIR technique leads to detailed structural information without the requirement for determination of additional parameters for quantitative analysis except calibration. Appropriate experimental conditions for preferential solvation study have been established by variation of polymer concentration, molar mass and eluent content.

  6. Dissecting functions of the retinoblastoma tumor suppressor and the related pocket proteins by integrating genetic, cell biology, and electrophoretic techniques

    DEFF Research Database (Denmark)

    Hansen, Klaus; Lukas, J; Holm, K;

    1999-01-01

    The members of the 'pocket protein' family, comprising the retinoblastoma tumor suppressor (pRB) and its relatives, p107 and p130, negatively regulate cell proliferation and modulate fundamental biological processes including embryonic development, differentiation, homeostatic tissue renewal...... phosphorylation events on multiple serine and threonine residues of pRB, p107, and p130, events which are carried out, at least in part, by the cyclin-dependent kinases that form the key elements of the cell cycle machinery. Here we discuss the recently obtained new insights into the diverse functions of the pRB...

  7. Characterization of Highly Efficient CdTe Thin Film Solar Cells by the Capacitance-Voltage Profiling Technique

    Science.gov (United States)

    Okamoto, Tamotsu; Yamada, Akira; Konagai, Makoto

    2000-05-01

    The electrical properties of highly efficient CdTe thin film solar cells prepared by close-spaced sublimation (CSS) were investigated by capacitance-voltage (C-V) measurement. According to the dependence of the cell performance on the substrate temperature in the CSS process, the open-circuit voltage (Voc) increased with increasing the substrate temperature below 630°C@. The carrier concentration profiles revealed that the net acceptor concentration exponentially increased from the CdS/CdTe interface to the rear and that the acceptor concentration increased with increasing substrate temperature. This result suggests that Voc is improved as a result of the increase in the acceptor concentration.

  8. A novel technique for making open-cell Al2O3-ZrO2 ceramic foam with plant seed template

    Directory of Open Access Journals (Sweden)

    Yu Jingyuan

    2010-08-01

    Full Text Available The aim of the present research is to provide a technique for preparing open-cell Al2O3-ZrO2 ceramic foams with uniform cell size. This technique used plant seeds to array templates and centrifugal slip casting to obtain cell struts with high packing density. Aqueous Al2O3-ZrO2 slurries with up to 50 vol.% solid contents were prepared and the rheological characteristic of the slurries was investigated. Consolidation was performed at an acceleration of 2,860 g for 60 min. The effect of the characteristic of plant seeds on the drying behavior of Al2O3-ZrO2 green compact was analyzed. The effects of the solid contents of slurries on segregation phenomena of Al2O3 and ZrO2 particles and green compact uniformity were investigated. The compressive stress-strain curve and deformation behavior of Al2O3-ZrO2 ceramic foams prepared using plant seed template were analyzed. The results showed segregation phenomenon is negligible for highly stable slurry with 50 vol.% solid loading. The prepared cell struts of Al2O3-ZrO2 foams have high green density (61.9% TD, sintered density (99.1% TD and homogeneous microstructure. When sintered at 1,550 篊 for 2 h, the cell size of Al2O3-ZrO2 foam is approximately uniform and the diameter is about 1.1 mm. The porosity and compressive strength of sintered products is 66.2% and 5.86 MPa, respectively.

  9. A reproducible technique combining tritiated thymidine autoradiography with immunodetection of bromodeoxyuridine for double labelling studies of cell proliferation in paraffin sections of tissues.

    Science.gov (United States)

    Hume, W J

    1990-05-01

    A method is described to combine tritiated thymidine autoradiography with immunoperoxidase detection of bromodeoxyuridine on the same paraffin sections. It overcomes the varied technical artefacts we encountered when first attempting to combine these techniques and results in preparations with extremely low peroxidase and autoradiographic backgrounds. In particular, we find it is important to avoid the use of detergents during immunostaining, otherwise grain counts are reduced and autoradiograph exposures need to be greatly increased, and to avoid excessive peroxidase staining which makes it difficult to visualize silver grains in the overlying emulsion. The advantages of a method to remove emulsion films using acid-alcohol, allowing the same sections to be dipped twice with a long and a short autoradiographic exposure, are presented. The routine combination of high quality tritiated thymidine autoradiography with clean immunoperoxidase staining of bromodeoxyuridine-positive nuclei provides a new and powerful cell kinetic, double-labelling method to augment existing techniques e.g. by labelling the same cells undergoing DNA synthesis in successive cell cycles.

  10. Invoking the frequency dependence in square modulated light intensity techniques for the measurement of electron time constants in dye-sensitized solar cells

    Science.gov (United States)

    Ghaithan, Hamid M.; Qaid, Saif M.; Hezam, Mahmoud; Siddique, Muhemmad B.; Bedja, Idriss M.; Aldwayyana, Abdullah S.

    2015-08-01

    Dye-sensitized solar cells (DSSCs) have been considered as one of the most promising new generation solar cells. Enormous research efforts have been invested to improve the efficiency of solar energy conversion which is determined by the light harvesting efficiency, electron injection efficiency and undesirable electron lifetime. A simple, cheap and trustable laser-induced photovoltage and photocurrent decay (LIPVCD) technique is adopted in this work in order to determine the electron lifetime (τe) and electron transport (τtr) in DSSCs. In LIPVCD technique, DSSC is illuminated by a small squared intensity-modulated laser beam. Time-based response of the DSSC is recorded using a transient digitized oscilloscope for further analysis. Frequency-based response was also investigated in this work. The frequency-dependent measurements turned out to be a powerful method to determine electron time constants in a fast, real-time fashion. Measurements were carried out using a standard dye-sensitized solar cell, and results were in excellent agreement with results obtained from traditional IMVS-MPS measurements. Measurements were also performed for a variety of DSSCs, having various electrodes including TiO2 nanoparticles, TiO2 nanosheets with exposed {001} facets and ZnO vertically aligned nanowires. Results will also be presented and discussed in this work.

  11. An effort to test the embryotoxicity of benzene, toluene, xylene, and formaldehyde to murine embryonic stem cells using airborne exposure technique.

    Science.gov (United States)

    Shen, Shuijie; Yuan, Lingmin; Zeng, Su

    2009-10-01

    Benzene, toluene, xylene, and formaldehyde are well-known indoor air pollutants, especially after house decoration. They are also common pollutants in the working places of the plastic industry, chemical industry, and leather industry. It has been reported that these pollutants cause people to be irritated, sick, experience a headache, and be dizzy. They also have the potential to induce asthma, aplastic anemia, and leukemia, even cause abortion or fetus malformation in humans. In this study, the airborne toxicity of benzene, toluene, xylene, and formaldehyde to murine embryonic stem cells (mES cells) were tested using airborne exposure technique to evaluate the mES cell airborne exposure model on embryotoxicity prediction. Briefly, mES cells were cultured on Transwell inserts and were exposed to an airborne surrounding of test chemicals in a chamber for 1 h at 37 degrees C. Cytotoxicity was determined using the MTT assay after further culture for 18 h at 37 degrees C in normal medium. The airborne IC(50) (50% inhibition concentration) of benzene, toluene, xylene, and formaldehyde derived from the fitted dose-response curves were 17,400 +/- 1290, 16,000 +/- 250, 4680 +/- 500, and 620 +/- 310 ppm, respectively. Formaldehyde was found to be the compound most toxic to mES cells compared to benzene homologues. The toxicity data had good correlation with the in vivo data. The results showed that the mES airborne exposure model may be used to predict embryotoxicity of volatile organic compounds.

  12. The potential of metabolomic analysis techniques for the characterisation of α1-adrenergic receptors in cultured N1E-115 mouse neuroblastoma cells.

    Science.gov (United States)

    Wenner, Maria I; Maker, Garth L; Dawson, Linda F; Drummond, Peter D; Mullaney, Ian

    2016-08-01

    Several studies of neuropathic pain have linked abnormal adrenergic signalling to the development and maintenance of pain, although the mechanisms underlying this are not yet fully understood. Metabolomic analysis is a technique that can be used to give a snapshot of biochemical status, and can aid in the identification of the mechanisms behind pathological changes identified in cells, tissues and biological fluids. This study aimed to use gas chromatography-mass spectrometry-based metabolomic profiling in combination with reverse transcriptase-polymerase chain reaction and immunocytochemistry to identify functional α1-adrenergic receptors on cultured N1E-115 mouse neuroblastoma cells. The study was able to confirm the presence of mRNA for the α1D subtype, as well as protein expression of the α1-adrenergic receptor. Furthermore, metabolomic data revealed changes to the metabolite profile of cells when exposed to adrenergic pharmacological intervention. Agonist treatment with phenylephrine hydrochloride (10 µM) resulted in altered levels of several metabolites including myo-inositol, glucose, fructose, alanine, leucine, phenylalanine, valine, and n-acetylglutamic acid. Many of the changes observed in N1E-115 cells by agonist treatment were modulated by additional antagonist treatment (prazosin hydrochloride, 100 µM). A number of these changes reflected what is known about the biochemistry of α1-adrenergic receptor activation. This preliminary study therefore demonstrates the potential of metabolomic profiling to confirm the presence of functional receptors on cultured cells.

  13. Detection of human immunodeficiency virus DNA in cultured human glial cells by means of the polymerase chain reaction

    DEFF Research Database (Denmark)

    Teglbjærg, Lars Stubbe; Hansen, J-ES; Dalbøge, H;

    1991-01-01

    This report describes the use of the polymerase chain reaction (PCR) for the detection of viral genomic sequences in latently infected cells. Infection with human immunodeficiency virus in cultures of human glial cells was demonstrated, using nucleic acid amplification followed by dot blot...... hybridization. It was not possible to detect any viral antigen production in the cultures, and attempts to recover virus by highly sensitive coculture techniques were unsuccessful, indicating that the infection was latent. The PCR technique provides a simple approach to the study of viral infection in cases...

  14. Light and electron microscopic localization of GABAA-receptors on cultured cerebellar granule cells and astrocytes using immunohistochemical techniques

    DEFF Research Database (Denmark)

    Hansen, G H; Hösli, E; Belhage, B;

    1991-01-01

    GABAA-receptors were localized in explant cultures of rat cerebellum and in dissociated primary cultures of rat cerebellar granule cells and rat cerebellar astrocytes using the monoclonal antibody bd-17 directed against the beta-subunit of the GABAA/benzodiazepine/chloride channel complex. At the...

  15. Charge-discharge studies on a lithium cell composed of PVdF-HFP polymer membranes prepared by phase inversion technique with a nanocomposite cathode

    Science.gov (United States)

    Manuel Stephan, A.; Teeters, Dale

    A novel polymer membrane of poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) co-polymer was prepared by the phase inversion technique with two different non-solvents, 1-butanol or hexane. The prepared films were analyzed by scanning electron microscope (SEM) and nitrogen absorption/desorption techniques. The change in the morphology and pore diameter of the films prepared with different non-solvents correlates with the structure of the non-solvents used. This electrolyte membrane was coupled with a nanocomposite LiAl 0.01Co 0.99O 2 cathode which was prepared by a solid-state reaction method and subsequently by ball-milling. Lithium cells consisting of LiAl 0.01Co 0.99O 2/polymer electrolyte/Li were assembled and their charge-discharge studies were investigated.

  16. A simple explanation for a case of incompatibility with the reading frame theory in Duchenne muscular dystrophy: failure to detect an aberrant restriction fragment in Southern blot analysis.

    Science.gov (United States)

    Patria, S Y; Takeshima, Y; Suminaga, R; Nakamura, H; Iwasaki, R; Minagawa, T; Matsuo, M

    1999-09-01

    According to the translational reading frame theory, Duchenne muscular dystrophy (DMD) patients harbor out-of-frame deletion mutations in the dystrophin gene. We identified a Japanese DMD case who appeared to have an in-frame deletion of exons 46-54 that was disclosed by Southern blot analysis using a dystrophin cDNA as a probe. Analysis of dystrophin mRNA in skeletal muscle revealed the presence of an out-of-frame deletion of exons 46-53. In agreement with this result, the region encompassing exon 54 could be amplified from genomic DNA by polymerase chain reaction (PCR). Furthermore, re-analysis by Southern blot using an exon specific probe disclosed that a HindIII fragment containing exon 54 was present at aberrant size, leading to the incorrect conclusion that exon 54 had been deleted. Thus, this particular DMD case does not constitute an exception to the reading frame theory.

  17. Characterization of Sm14 related components in different helminths by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and Western blotting analysis

    Directory of Open Access Journals (Sweden)

    Nilton Thaumaturgo

    2002-10-01

    Full Text Available Sm14 was the first fatty acid-binding protein homologue identified in helminths. Thereafter, members of the same family were identified in several helminth species, with high aminoacid sequence homology between them. In addition, immune crossprotection was also reported against Fasciola hepatica infection, in animals previously immunized with the Schistosoma mansoni vaccine candidate, r-Sm14. In the present study, data on preliminary sodium dodecyl sulphate-polyacrylamide gel electrophoresis and Western blotting analysis of nine different helminth extracts focusing the identification of Sm14 related proteins, is reported. Out of these, three extracts - Ascaris suum (males and females, Echinostoma paraensei, and Taenia saginata - presented components that comigrated with Sm14 in SDS-PAGE, and that were recognized by anti-rSm14 policlonal serum, in Western blotting tests.

  18. Analysis of the Crude Antigen of Hymenolepis nana from Mice by SDS-PAGE and the Determination of Specific Antigens in Protein Structure by Western Blotting

    OpenAIRE

    GÖNENÇ, Bahadır

    2002-01-01

    Protein bands of crude antigens of Hymenolepis nana were determined by SDS-PAGE and Western blotting. Thirty Swiss albino mice were allotted into two groups of 15 each as positive (infected with H. nana) and negative (non-infected with H. nana) groups. The natural infections of H. nana and other helminths were determined by centrifugal flotation of faeces. After bleeding, the mice were necropsied and their guts were examined for H. nana and other intestinal helminths. Sera from mice were test...

  19. Transplant related ocular surface disorders: Advanced techniques for ocular surface rehabilitation after ocular complications secondary to hematopoietic stem cell transplantation.

    Science.gov (United States)

    Stahl, Erin D; Mahomed, Faheem; Hans, Amneet K; Dalal, Jignesh D

    2016-05-01

    HSCT has been linked to the development of an assortment of ocular surface complications with the potential to lead to permanent visual impairment if left untreated or if not treated early in the course of disease. Strategies for therapy include maintenance of lubrication and tear preservation, prevention of evaporation, decreasing inflammation, and providing epithelial support. The ultimate aim of treatment is to prevent permanent ocular sequelae through prompt ophthalmology consultation and the use of advanced techniques for ocular surface rehabilitation. We describe several rehabilitation options of ocular surface complications occurring secondarily during the post-HSCT course.

  20. Application of the MOS C-V technique to determine impurity concentrations and surface parameters on the diffused face of silicon solar cells

    Science.gov (United States)

    Weinberg, I.

    1975-01-01

    An experimental and theoretical investigation of the feasibility of using the MOS C-V (capacitance-voltage) technique to determine impurity and surface state concentrations on the diffused face of Si solar cells with Ta2O5 coatings. Impurity concentration 10 A from the diffused surface is found to be 2.9 times 10 to the 20th power per cu cm. Charge density in surface and oxide states is 2.1 times 10 to the 13th power per sq cm. These data agree with theoretical predictions.-

  1. Quantitative Expression Analysis in Brassica napus by Northern Blot Analysis and Reverse Transcription-Quantitative PCR in a Complex Experimental Setting.

    Science.gov (United States)

    Rumlow, Annekathrin; Keunen, Els; Klein, Jan; Pallmann, Philip; Riemenschneider, Anja; Cuypers, Ann; Papenbrock, Jutta

    Analysis of gene expression is one of the major ways to better understand plant reactions to changes in environmental conditions. The comparison of many different factors influencing plant growth challenges the gene expression analysis for specific gene-targeted experiments, especially with regard to the choice of suitable reference genes. The aim of this study is to compare expression results obtained by Northern blot, semi-quantitative PCR and RT-qPCR, and to identify a reliable set of reference genes for oilseed rape (Brassica napus L.) suitable for comparing gene expression under complex experimental conditions. We investigated the influence of several factors such as sulfur deficiency, different time points during the day, varying light conditions, and their interaction on gene expression in oilseed rape plants. The expression of selected reference genes was indeed influenced under these conditions in different ways. Therefore, a recently developed algorithm, called GrayNorm, was applied to validate a set of reference genes for normalizing results obtained by Northern blot analysis. After careful comparison of the three methods mentioned above, Northern blot analysis seems to be a reliable and cost-effective alternative for gene expression analysis under a complex growth regime. For using this method in a quantitative way a number of references was validated revealing that for our experiment a set of three references provides an appropriate normalization. Semi-quantitative PCR was prone to many handling errors and difficult to control while RT-qPCR was very sensitive to expression fluctuations of the reference genes.

  2. Development of technique for AR coating and nickel and copper metallization of solar cells: FPS project, product development

    Science.gov (United States)

    Rominger, C. G.

    1981-01-01

    Silicon nitride and nickel pastes are investigated in conjunction with a brush copper plating process for the purpose of identifying one or more fabrication sequences which yield at least 10 percent efficient N(+)/P(+) flat plate solar cells. The adhesion of all nickel pastes is reduced significantly when subjected to acidic and alkaline brush copper plating solutions as a result of a combination of thermally induced stress and chemical attack of the frit, which occurs at the interface with the silicon solar cell. The AgF is penetrating the 800 a of Si3N4 and ohmic contact is occurring at all fire-in tempertures. During the brush plating process, fingers and buss bars tend to spread.

  3. Production of alkaline protease with immobilized cells of bacillus subtilis PE-11 in various matrices by entrapment technique

    OpenAIRE

    Adinarayana, Kunamneni; Jyothi, Bezawada; Ellaiah, Poluri

    2005-01-01

    The purpose of this investigation was to study the effect ofBacillus subtilis PE-11 cells immobilized in various matrices, such as calcium alginate, k-Carrageenan, ployacrylamide, agar-agar, and gelatin, for the production of alkaline protease. Calcium alginate was found to be an effective and suitable matrix for higher alkaline protease productivity compared to the other matrices studied. All the matrices were selected for repeated batch fermentation. The average specific volumetric producti...

  4. Challenges and perspectives to enhance cattle production via in vitro techniques: focus on epigenetics and cell-secreted vesicles

    Directory of Open Access Journals (Sweden)

    Fabiana Fernandes Bressan

    2015-10-01

    Full Text Available This review aim to present some clinical problems found in IVP-derived animals focusing on NT procedures and to discuss the possible role of epigenetics in such process. Also, as cell-secreted vesicles have been reported as possible regulators of important physiological reproductive processes such as folliculogenesis and fertilization, it is also presented herein a new perspective of manipulating the pre-implantation period trough effector molecules contained in such vesicles.

  5. Production technique for fuel cells: from handicraft to robot based manufacturing process; Herstelltechnik fuer Brennstoffzellen: Vom Handwerk zu robotergestuetzten Fertigungsverfahren

    Energy Technology Data Exchange (ETDEWEB)

    Joerissen, L.; Einhart, H.; Scholta, J.; Konold, P. [ZSW, Ulm (Germany); Wehrheim, M. [Hochschule Ulm (Germany)

    2008-07-01

    Polymer Electrolyte membrane Fuel Cell (PEFC) stacks are currently manufactured in small numbers using mainly manual manufacturing processes. Despite the fact that components such as Membrane Electrode Assemblies (MEA), bipolar plates, Gas Diffusion Layers (GDL) etc. are already being manufactured industrially by automated processes, the components are not yet optimized for subsequent stack assembly. Taking this into account, manual assembly processes are advantageous as compared to automated processes. Fuel cell stacks are consisting of many parts repeating each cell which need to be assembled gas tight and electrically conducting. This imposes tough requirements concerning production tolerances of the single components as well as accuracy of positioning during assembly. Manual assembly of large numbers of identical parts is quite sensitive in this respect. Handling parts of strongly different rigidity during stack assembly poses an additional challenge. Positioning and joining parts with different haptics can be done in a controlled manner when using manual assembly. Automated stack assembly requires the development of special picking technology. In this chapter two different concepts for stack assembly will be presented and discussed with respect to automatization at a later stage. (orig.)

  6. Trueness-to-type and agronomic characteristics of Coffea arabica trees micropropagated by the embryogenic cell suspension technique.

    Science.gov (United States)

    Etienne, H; Bertrand, B

    2001-09-01

    Trueness-to-type and agronomic characteristics of trees of four coffee (Coffea arabica L.) F(1) hybrid clones derived from embryogenic cell suspensions were compared with those of trees produced from in vitro microcuttings. Three types of variants were observed among the 644 trees derived from embryogenic suspensions. Total frequency of the variants was 2.1% for trees originating from embryogenic cell suspensions, whereas no variant was found among the trees produced from microcuttings. The variant known as "thick leaf" had thick leaves, many abnormally starry flowers and low yields of large fruit. The "dwarf" variant was characterized by slow growth and small fruit. The "dwarf peaberry" variant had abnormal seeds in a single cavity, in addition to the "thick leaf" and "dwarf" characteristics. Compared with normal trees, the variants differed in leaf density and number of chloroplasts per guard cell. The variants aside, there were no differences in the main agronomic characteristics between trees produced from embryogenic suspensions and those produced from microcuttings. For all four clones, the trees had vegetative characteristics, productivity, fertility, and bean biochemical, mineral and organoleptic characteristics that were identical to those of the controls. We conclude that it is possible to generate coffee trees commercially with normal agronomic performance from embryogenic suspensions, because the frequency with which somaclonal variants occur is limited.

  7. Research Techniques Made Simple: Noninvasive Imaging Technologies for the Delineation of Basal Cell Carcinomas.

    Science.gov (United States)

    Que, Syril Keena T

    2016-04-01

    In this article we discuss the development of noninvasive imaging modalities to help delineate tumor margins of basal cell carcinomas in the setting of Mohs micrographic surgery. A review of the available literature reveals that dermoscopy can help delineate basal cell carcinomas before surgical removal but that it has no benefit over clinical inspection in reducing the number of Mohs stages. In contrast, fluorescence confocal microscopy has a sensitivity of 88-96% and specificity of 89-99% for the detection of basal cell carcinomas and can potentially serve as a rapid means for tumor evaluation on ex vivo specimens. Optical coherence tomography has shown some success in the presurgical evaluation of tumor margins in vivo, before surgical excision. With ongoing developments in device portability, speed of image retrieval, and image resolution, these technologies are likely to gain traction in cutaneous oncology research and practice. It is therefore important for dermatology clinicians and researchers to understand the mechanisms, principal uses, advantages, and limitations of each device.

  8. Generation of Multilayered 3D Structures of HepG2 Cells Using a Bio-printing Technique

    Science.gov (United States)

    Jeon, Hyeryeon; Kang, Kyojin; Park, Su A; Kim, Wan Doo; Paik, Seung Sam; Lee, Sang-Hun; Jeong, Jaemin; Choi, Dongho

    2017-01-01

    Background/Aims Chronic liver disease is a major widespread cause of death, and whole liver transplantation is the only definitive treatment for patients with end-stage liver diseases. However, many problems, including donor shortage, surgical complications and cost, hinder their usage. Recently, tissue-engineering technology provided a potential breakthrough for solving these problems. Three-dimensional (3D) printing technology has been used to mimic tissues and organs suitable for transplantation, but applications for the liver have been rare. Methods A 3D bioprinting system was used to construct 3D printed hepatic structures using alginate. HepG2 cells were cultured on these 3D structures for 3 weeks and examined by fluorescence microscopy, histology and immunohistochemistry. The expression of liver-specific markers was quantified on days 1, 7, 14, and 21. Results The cells grew well on the alginate scaffold, and liver-specific gene expression increased. The cells grew more extensively in 3D culture than two-dimensional culture and exhibited better structural aspects of the liver, indicating that the 3D bioprinting method recapitulates the liver architecture. Conclusions The 3D bioprinting of hepatic structures appears feasible. This technology may become a major tool and provide a bridge between basic science and the clinical challenges for regenerative medicine of the liver. PMID:27559001

  9. 细胞共培养技术在医药研究中的应用%Application of cell co-culture techniques in medical studies

    Institute of Scientific and Technical Information of China (English)

    罗云; 孙桂波; 秦蒙; 姚帆; 孙晓波

    2012-01-01

    细胞共培养由于能更好地模拟体内环境,便于更好的观察细胞与细胞、细胞与培养环境之间的相互作用以及探讨药物的作用机制和可能的作用靶点,填补了单层细胞培养与整体动物实验研究的鸿沟,近年来倍受医药领域的关注,成为药物研发、生物制药领域的研究热点.细胞共培养方法包括直接共培养和间接共培养,主要用于疾病病理基础、新型治疗手段以及药物活性筛选的研究.现有的细胞共培养技术主要用于单一药物的药效学研究,用于联合药物相互作用的研究甚少.中药复方之间协同配伍,减毒增效.细胞共培养技术符合中药多成分、多靶点的作用特点,这对于未来探讨中药联合用药对机体的作用及机制的研究具有一定参考价值,为中药及复方研究提供了一种新的手段.该文就细胞共培养技术的方法与运用进行了概述,并对该技术运用于中药及复方的研究进行了展望.%As the cell co-culture techniques can better imitate an in vivo environment, it is helpful in observing the interactions among cells and between cells and the culture environment, exploring the effect mechanisms of drugs and their possible targets and filling the gaps between the mono-layer cell culture and the whole animal experiments. In recently years, they has attracted much more attention from the medical sector, and thus becoming one of research hotspots in drug research and development and bio-pharmaceutical fields. The cell co-culture techniques, including direct and indirect methods, are mainly used for studying pathological basis, new-type treatment methods and drug activity screening. Existing cell co-culture techniques are used for more pharmacological studies on single drug and less studies on interaction of combined drugs, such as collaborative compatibility and attenuation and synergistic effect among traditional Chinese medicines (TCMs). In line with the action

  10. Isolation and measurement of the features of arrays of cell aggregates formed by dielectrophoresis using the user-specified Multi Regions Masking (MRM) technique

    Energy Technology Data Exchange (ETDEWEB)

    Yusvana, Rama; Markx, Gerard H [School of Engineering and Physical Science, Department of Chemical Engineering, Heriot-Watt University, Riccarton Campus, Edinburgh - EH14 4AS (United Kingdom); Headon, Denis, E-mail: g.h.markx@hw.ac.u [Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian, Edinburgh - EH25 9PS (United Kingdom)

    2009-08-01

    The use of dielectrophoresis for the construction of artificial skin tissue with skin cells in follicle-like 3D cell aggregates in well-defined patterns is demonstrated. To analyse the patterns produced and to study their development after their formation a Virtual Instrument (VI) system was developed using the LabVIEW IMAQ Vision Development Module. A series of programming functions (algorithms) was used to isolate the features on the image (in our case; the patterned aggregates) and separate them from all other unwanted regions on the image. The image was subsequently converted into a binary version, covering only the desired microarray regions which could then be analysed by computer for automatic object measurements. The analysis utilized the simple and easy-to-use User-Specified Multi-Regions Masking (MRM) technique, which allows one to concentrate the analysis on the desired regions specified in the mask. This simplified the algorithms for the analysis of images of cell arrays having similar geometrical properties. By having a collection of scripts containing masks of different patterns, it was possible to quickly and efficiently develop sets of custom virtual instruments for the offline or online analysis of images of cell arrays in the database.

  11. Advanced Antenna Techniques and High Order Sectorization with Novel Network Tessellation for Enhancing Macro Cell Capacity in DC-HSDPA Network

    Directory of Open Access Journals (Sweden)

    Muhammad Usman Sheikh

    2013-10-01

    Full Text Available Mobile operators commonly use macro cells with traditional wide beam antennas for wider coverage in thecell, but future capacity demands cannot be achieved by using them only. It is required to achieve maximumpractical capacity from macro cells by employing higher order sectorization and by utilizing all possibleantenna solutions including smart antennas. This paper presents enhanced tessellation for 6-sector sitesand proposes novel layout for 12-sector sites. The main target of this paper is to compare the performanceof conventional wide beam antenna, switched beam smart antenna, adaptive beam antenna and differentnetwork layouts in terms of offering better received signal quality and user throughput. Splitting macro cellinto smaller micro or pico cells can improve the capacity of network, but this paper highlights theimportance of higher order sectorization and advance antenna techniques to attain high Signal toInterference plus Noise Ratio (SINR, along with improved network capacity. Monte Carlo simulations atsystem level were done for Dual Cell High Speed Downlink Packet Access (DC-HSDPA technology withmultiple (five users per Transmission Time Interval (TTI at different Intersite Distance (ISD. Theobtained results validate and estimate the gain of using smart antennas and higher order sectorization withproposed network layout.

  12. Covalent attachment of cell-adhesive peptide Gly-Arg-Gly-Asp (GRGD) to poly(etheretherketone) surface by tailored silanization layers technique

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Yanyan [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Xiong, Chengdong [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China); Li, Xiaoyu [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China); Zhang, Lifang, E-mail: zhanglfcioc@163.com [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China)

    2014-11-30

    Highlights: • The carbonyl groups on PEEK surface were effectively reduced to hydroxyl groups using sodium borohydride. • Silanization layers technique was employed to immobilize the cell-adhesive peptide Gly-Arg-Gly-Asp (GRGD) on hydroxylation-pretreated PEEK sheet surface by covalent chemical attachment. • XPS, surface profiler and water contact angle measurements proved the presence of GRGD on PEEK surface. • Osteoblast-like cells (MC3T3-E1) attachment and proliferation were improved effectively on GRGD-modified PEEK surface. - Abstract: Poly(etheretherketone) (PEEK) is a rigid semicrystalline polymer that combines excellent mechanical properties, broad chemical resistance and bone-like stiffness and is widely used in biomedical fields. However, PEEK is naturally bioinert, leading to limited biomedical applications, especially when a direct bone-implant osteointegration is desired. In this study, a three-step reaction procedure was employed to immobilize the cell-adhesive peptide Gly-Arg-Gly-Asp (GRGD) on the surface of PEEK sheet by covalent chemical attachment to favor cell adhesion and proliferation. First, hydroxylation-pretreated PEEK surfaces were silanized with 7-Oct-1-enyltrichlorosilane (OETS) in dry cyclohexane, resulting in a silanization layer with terminal ethenyl. Second, the terminal ethylenic double bonds of the silanization layer on PEEK surface were converted to carboxyl groups through acidic potassium manganate oxidation. Finally, GRGD was covalently attached by carbodiimide mediated condensation between the carboxyl on PEEK surface and amine presents in GRGD. X-ray photoelectron spectroscopy (XPS), attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, surface profiler and water contact angle measurements were applied to characterize the modified surfaces. The effect of cells attachment and proliferation on each specimen was investigated. Pre-osteoblast cells (MC3T3-E1) attachment, spreading and proliferation

  13. Phytoestrogens regulate the proliferation and expression of stem cell factors in cell lines of malignant testicular germ cell tumors.

    Science.gov (United States)

    Hasibeder, Astrid; Venkataramani, Vivek; Thelen, Paul; Radzun, Heinz-Joachim; Schweyer, Stefan

    2013-11-01

    Phytoestrogens have been shown to exert anti-proliferative effects on different cancer cells. In addition it could be demonstrated that inhibition of proliferation is associated with downregulation of the known stem cell factors NANOG, POU5F1 and SOX2 in tumor cells. We demonstrate the potential of Belamcanda chinensis extract (BCE) and tectorigenin as anticancer drugs in cell lines of malignant testicular germ cell tumor cells (TGCT) by inhibition of proliferation and regulating the expression of stem cell factors. The TGCT cell lines TCam-2 and NTera-2 were treated with BCE or tectorigenin and MTT assay was used to measure the proliferation of tumor cells. In addition, the expression of stem cell factors was analyzed by quantitative PCR and western blot analysis. Furthermore, global expression analysis was performed by microarray technique. BCE and tectorigenin inhibited proliferation and downregulated the stem cell factors NANOG and POU5F1 in TGCT cells. In addition, gene expression profiling revealed induction of genes important for the differentiation and inhibition of oncogenes. Utilizing connectivity map in an attempt to elucidate mechanism underlying BCE treatments we found highly positive association to histone deacetylase inhibitors (HDACi) amongst others. Causing no histone deacetylase inhibition, the effects of BCE on proliferation and stem cell factors may be based on histone-independent mechanisms such as direct hyperacetylation of transcription factors. Based on these findings, phytoestrogens may be useful as new agents in the treatment of TGCT.

  14. High-efficiency CdTe thin-film solar cells using metalorganic chemical vapor deposition techniques

    Science.gov (United States)

    Nouhi, A.; Stirn, R. J.; Meyers, P. V.; Liu, C. H.

    1989-01-01

    Energy conversion efficiency of metalorganic chemical vapor deposited CdTe as an intrinsic active layer in n-i-p solar cell structures is reported. Small-area devices with efficiencies over 9 percent have been demonstrated. I-V characteristics, photospectral response, and the results of Auger profiling of structural composition for typical devices will be presented. Also presented are preliminary results on similar photovoltaic devices having Cd(0.85)Mn(0.15)Te in place of CdTe as an i layer.

  15. A New Technique to Produce Electricity Using Solar Cell in Aspect of Bangladesh: Dye-Sensitized Solar Cell (DSSC and It’s Prospect

    Directory of Open Access Journals (Sweden)

    M. F. Ali

    2014-09-01

    Full Text Available The Bangladesh is a developing country where electricity crisis is the most serious problem now-a-days. In order to meet electricity demand of our country we need to change the procedure of electricity production. For that we have to implement our renewable energy resources properly like solar cell. The dye sensitized solar cell (DSSCs is another new method to produce electricity which is more cost effective and also efficient comparing conventional silicon solar cell. When the visible light is absorbed by the thin film such as TiO2, an electron is injected by the excited sensitizer molecules into the conduction band of that thin film (TiO2. These electrons are then transported toward and collected by a back-contact electrode which travel in a big circle and create an electrical circuit which powers a device. In this paper we tried to describe the new DSSCs technology compared to conventional silicon solar cell according to the electricity demand of Bangladesh.

  16. Extraction of Natural Antioxidants from the Thelephora ganbajun Mushroom by an Ultrasound-Assisted Extraction Technique and Evaluation of Antiproliferative Activity of the Extract against Human Cancer Cells.

    Science.gov (United States)

    Xu, Dong-Ping; Zheng, Jie; Zhou, Yue; Li, Ya; Li, Sha; Li, Hua-Bin

    2016-10-01

    The Thelephora ganbajun mushroom has been found to be a potential rich source of natural antioxidants. In this study, an ultrasound-assisted extraction (UAE) technique together with GRAS (generally recognized as safe) solvents (ethanol and water) was used to maximize the extraction of antioxidants from Thelephora ganbajun. Five extraction parameters (ethanol concentration, solvent to solid ratio, extraction time, temperature and ultrasound power) were investigated by single-factor experiments, and then a central composite rotatable design was employed to study interaction of three key extraction parameters. The optimum conditions were as follows: 57.38% ethanol, 70.15 mL/g solvent to solid ratio, 10.58 min extraction time, 40 °C extraction temperature and 500 W ultrasound power. Under the optimum conditions, the antioxidant activity obtained was 346.98 ± 12.19 µmol Trolox/g DW, in accordance with the predicted value of 344.67 µmol Trolox/g DW. Comparison of UAE with conventional maceration and Soxhlet extraction, the UAE method showed stronger extract efficiency in a shorter extraction time. These results showed that UAE was an effective technique to extract antioxidants from Thelephora ganbajun. Furthermore, the extracts obtained under the optimized conditions exhibited antiproliferative activities toward human lung (A549), breast (MCF-7), liver (HepG2) and colon (HT-29) cancer cells, especially for liver and lung cancer cells. In addition, rutin, 2-hydrocinnamic acid and epicatechin were identified in the extract, which might contribute to antioxidant and antiproliferative activities.

  17. Agarose cell block technique as a complementary method in the diagnosis of fungal osteomyelitis in a dog

    Directory of Open Access Journals (Sweden)

    N.S. Rocha

    2012-04-01

    Full Text Available A 7-year-old Labrador Retriever female dog presenting left forelimb lameness for one day was admitted to the Veterinary Hospital (UNESP-Botucatu for clinical evaluation. Several tests, including blood and image analysis, microbiological culture and cytology of lytic areas of affected bone were made in order to establish a diagnosis. Serum biochemical profile revealed increased levels of liver enzymes, plasma globulin, creatine kinase (CK and calcium. Hemogram revealed anemia and leukocytosis; left humerus image analysis revealed an osteolytic lesion and cytology revealed a suppurative periostitis. Differential diagnosis was a nonspecific infectious inflammatory process or osteosarcoma. Since it was not possible to achieve a definitive diagnosis and there was a highly suspicious for an infectious agent, an agarose cell block of the bone marrow fine-needle aspiration was made. The cytological examination of cell block presented similar findings as described previously. However, additional stains including periodic acid-Schiff (PAS were positive for fungal hyphae, which rendered a diagnosis of fungal osteomyelitis due to Aspergillus spp. This case report illustrates an uncommon cause of osteomyelitis for breed that was diagnosed by an underused method in veterinary medicine.

  18. Investigations on microstructural and optical properties of CdS films fabricated by a low-cost, simplified spray technique using perfume atomizer for solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Ravichandran, K.; Philominathan, P. [PG and Research Department of Physics, AVVM, Sri Pushpam College, Poondi, Thanjavur District, Tamil Nadu (India)

    2008-11-15

    Good quality CdS films were fabricated by employing a simplified spray pyrolysis technique using perfume atomizer. CdS films have been deposited from aqueous solutions of sulphur and cadmium, keeping the molar concentrations of S:Cd = 0.01:0.01, 0.02:0.02, 0.04:0.04 and 0.06:0.06 in the starting solutions. The structural studies reveal that the S:Cd concentration has a strong influence on the microstructural characteristics of the sprayed CdS films. It was found that there is a transition in the preferred orientation from (0 0 2) plane to (1 0 1) plane when S:Cd molar concentration increases. The SEM images depict that the films are uniform and homogeneous. All the films have high optical transmittance (>80%) in the visible range. The optical band gap values are found to be in the range of 2.46-2.52 eV. CdS films fabricated by this simple and economic spray technique without using any carrier gas are found to be good in structural and optical properties which are desirable for photovoltaic applications. Hence, this simplified version of spray technique can be considered as an economic alternative to conventional spray pyrolysis (using carrier gas), for the mass production of low-cost, large area CdS coatings for solar cell applications. (author)

  19. High performance dye-sensitized solar cells using graphene modified fluorine-doped tin oxide glass by Langmuir–Blodgett technique

    Energy Technology Data Exchange (ETDEWEB)

    Roh, Ki-Min [Rare Metals Research Center, Korea Institute of Geoscience and Mineral Resources, Daejeon 305-350 (Korea, Republic of); Jo, Eun-Hee; Chang, Hankwon [Rare Metals Research Center, Korea Institute of Geoscience and Mineral Resources, Daejeon 305-350 (Korea, Republic of); Nanomaterials Science and Engineering Major, University of Science and Technology, Daejeon 305-350 (Korea, Republic of); Han, Tae Hee [Department of Organic and Nano Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Jang, Hee Dong, E-mail: hdjang@kigam.re.kr [Rare Metals Research Center, Korea Institute of Geoscience and Mineral Resources, Daejeon 305-350 (Korea, Republic of); Nanomaterials Science and Engineering Major, University of Science and Technology, Daejeon 305-350 (Korea, Republic of)

    2015-04-15

    Since the introduction of dye-sensitized solar cells (DSSCs) with low fabrication cost and high power conversion efficiency, extensive studies have been carried out to improve the charge transfer rate and performance of DSSCs. In this paper, we present DSSCs that use surface modified fluorine-doped tin oxide (FTO) substrates with reduced graphene oxide (r-GO) sheets prepared using the Langmuir–Blodgett (LB) technique to decrease the charge recombination at the TiO{sub 2}/FTO interface. R-GO sheets were excellently attached on FTO surface without physical deformations such as wrinkles; effects of the surface coverage of r-GO on the DSSC performance were also investigated. By using graphene modified FTO substrates, the resistance at the interface of TiO{sub 2}/FTO was reduced and the power conversion efficiency was increased to 8.44%. - Graphical abstract: DSSCs with graphene modified FTO glass were fabricated with the Langmuir Blodgett technique. GO sheets were transferred to FTO at various surface pressures in order to change the surface density of graphene and the highest power conversion efficiency of the DSSC was 8.44%. - Highlights: • By LB technique, r-GO sheets were coated on FTO without physical deformation. • DSSCs were fabricated with, r-GO modified FTO substrates. • With surface modification by r-GO, the interface resistance of DSSC decreased. • Maximum PCE of the DSSC was increased up to 8.44%.

  20. Development of technique for AR coating and nickel and copper metallization of solar cells. FPS Project: Product development

    Science.gov (United States)

    Taylor, W.

    1982-01-01

    Printed nickel overplated with copper and applied on top of a predeposited silicon nitride antireflective coating system for metallizing solar cells was analyzed. The ESL D and E paste formulations, and the new formulations F, G, H, and D-1 were evaluated. The nickel thick films were tested after firing for stability in the cleaning and plating solutions used in the Vanguard-Pacific brush plating process. It was found that the films are very sensitive to the leaning and alkaline copper solutions. Less sensitivity was displayed to the neutral copper solution. Microscopic and SEM observations show segregation of frit at the silicon nitride thick film interface with loose frit residues after lifting off plated grid lines.

  1. Carbon nanotubes film preparation on 3D structured silicon substrates by spray coating technique for application in solar cells

    Science.gov (United States)

    Xiang, Y.; Li, M.; Lin, C.; Liu, P.; Zhang, J.

    2014-11-01

    This paper firstly reports the preparation of carbon nanotubes (CNTs) film on silicon substrate of three-dimensional (3D) inverted pyramid structure (IPS) by spray coating. The effect of different substrate temperatures, spraying times and opening sizes on CNTs sidewall covering properties were investigated. The results show that the CNTs covering ratio of sidewall is much lower than that of flat surface and gradually decrease with depth. 40μm×40μm opening obtained the best sidewall covering by CNTs suspension of 40μg/ml at 120°C after 30min spraying so that the CNTs can reach the bottom of IPS and cover about 68.9% sidewall area. At last, it is demonstrated that the output power of the CNTs film-Si solar cell can be enhanced 5.7 times by this method compared to that of the plane structure.

  2. Studies in the compartmentalization of trace elements in the blood of patients with sickle cell anaemia using PIXE technique

    Science.gov (United States)

    Ojo, J. O.; Oluwole, A. F.; Durosinmi, M. A.; Arsed, W.; Akanle, O. A.; Spyrou, N. M.

    1993-06-01

    Concentrations of trace elements in the whole blood, plasma and erythrocytes of 77 individuals (20 carrying the HbSS genotype, 21 with HbAS and 36 with HbAA) were determined using a PIXE facility employing a 2 MeV proton beam. Up to 16 elements were detected in some or all of the samples. The skewness of elemental distribution was measured for each element in the three bloodflow compartments. Most of the essential elements, apart from selenium were distinctly packed in either the erythrocytes or the plasma. Results of the t-test employed to compare elemental values between sickle cell subjects and matched controls show similar patterns in the three compartments for some of the elements. The results are compared with previous work using INAA.

  3. Multirate Particle-in-Cell Time Integration Techniques of Vlasov-Maxwell Equations for Collisionless Kinetic Plasma Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Guangye [Los Alamos National Laboratory; Chacon, Luis [Los Alamos National Laboratory; Knoll, Dana Alan [Los Alamos National Laboratory; Barnes, Daniel C [Coronado Consulting

    2015-07-31

    A multi-rate PIC formulation was developed that employs large timesteps for slow field evolution, and small (adaptive) timesteps for particle orbit integrations. Implementation is based on a JFNK solver with nonlinear elimination and moment preconditioning. The approach is free of numerical instabilities (ωpeΔt >>1, and Δx >> λD), and requires many fewer dofs (vs. explicit PIC) for comparable accuracy in challenging problems. Significant gains (vs. conventional explicit PIC) may be possible for large scale simulations. The paper is organized as follows: Vlasov-Maxwell Particle-in-cell (PIC) methods for plasmas; Explicit, semi-implicit, and implicit time integrations; Implicit PIC formulation (Jacobian-Free Newton-Krylov (JFNK) with nonlinear elimination allows different treatments of disparate scales, discrete conservation properties (energy, charge, canonical momentum, etc.)); Some numerical examples; and Summary.

  4. Evaluation of defects generation in crystalline silicon ingot grown by cast technique with seed crystal for solar cells.

    Science.gov (United States)

    Tachibana, Tomihisa; Sameshima, Takashi; Kojima, Takuto; Arafune, Koji; Kakimoto, Koichi; Miyamura, Yoshiji; Harada, Hirofumi; Sekiguchi, Takashi; Ohshita, Yoshio; Ogura, Atsushi

    2012-04-01

    Although crystalline silicon is widely used as substrate material for solar cell, many defects occur during crystal growth. In this study, the generation of crystalline defects in silicon substrates was evaluated. The distributions of small-angle grain boundaries were observed in substrates sliced parallel to the growth direction. Many precipitates consisting of light elemental impurities and small-angle grain boundaries were confirmed to propagate. The precipitates mainly consisted of Si, C, and N atoms. The small-angle grain boundaries were distributed after the precipitation density increased. Then, precipitates appeared at the small-angle grain boundaries. We consider that the origin of the small-angle grain boundaries was lattice mismatch and/or strain caused by the high-density precipitation.

  5. Conserved DNA methylation patterns in healthy blood cells and extensive changes in leukemia measured by a new quantitative technique.

    Science.gov (United States)

    Jelinek, Jaroslav; Liang, Shoudan; Lu, Yue; He, Rong; Ramagli, Louis S; Shpall, Elizabeth J; Estecio, Marcos R H; Issa, Jean-Pierre J

    2012-12-01

    Genome wide analysis of DNA methylation provides important information in a variety of diseases, including cancer. Here, we describe a simple method, Digital Restriction Enzyme Analysis of Methylation (DREAM), based on next generation sequencing analysis of methylation-specific signatures created by sequential digestion of genomic DNA with SmaI and XmaI enzymes. DREAM provides information on 150,000 unique CpG sites, of which 39,000 are in CpG islands and 30,000 are at transcription start sites of 13,000 RefSeq genes. We analyzed DNA methylation in healthy white blood cells and found methylation patterns to be remarkably uniform. Inter individual differences > 30% were observed only at 227 of 28,331 (0.8%) of autosomal CpG sites. Similarly, > 30% differences were observed at only 59 sites when we comparing the cord and adult blood. These conserved methylation patterns contrasted with extensive changes affecting 18-40% of CpG sites in a patient with acute myeloid leukemia and in two leukemia cell lines. The method is cost effective, quantitative (r ( 2) = 0.93 when compared with bisulfite pyrosequencing) and reproducible (r ( 2) = 0.997). Using 100-fold coverage, DREAM can detect differences in methylation greater than 10% or 30% with a false positive rate below 0.05 or 0.001, respectively. DREAM can be useful in quantifying epigenetic effects of environment and nutrition, correlating developmental epigenetic variation with phenotypes, understanding epigenetics of cancer and chronic diseases, measuring the effects of drugs on DNA methylation or deriving new biological insights into mammalian genomes.

  6. Dye-sensitized solar cell based on optically transparent TiO{sub 2} nanocrystalline electrode prepared by atomized spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Bandara, H.M.N., E-mail: hmnb@pdn.ac.l [Department of Chemistry, University of Peradeniya, Peradeniya (Sri Lanka); Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011 (Japan); Rajapakse, R.M.G. [Department of Chemistry, University of Peradeniya, Peradeniya (Sri Lanka); Murakami, K. [Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011 (Japan); Kumara, G.R.R.A.; Anuradha Sepalage, G. [Department of Chemistry, University of Peradeniya, Peradeniya (Sri Lanka)

    2011-10-30

    Highlights: > Transparent TiO{sub 2} films were prepared by the atomized spray pyrolysis method. > These films contain 3-5 nm discrete particles, interconnected to give a crack-free thin film structure. > Dye-absorption of the TiO{sub 2} film is 2.16 times higher than those used in conventional DSCs. > Conversion efficiency of 8.2% can be achieved with 1000 W m{sup -2} irradiation. - Abstract: Preparation of crack-free thin films of interconnected and non-agglomerated TiO{sub 2} nanoparticles on electronically conducting fluorine doped tin oxide surfaces is instrumental in designing and developing transparent dye-sensitized solar cells (DSCs). A novel technique called 'Atomized Spray Pyrolysis' (ASP) has been designed and developed to achieve such perfectly transparent thin films. Optical transmittance of TiO{sub 2} films produced on FTO surface by this ASP method has been compared with those obtained by doctor-blading and by hand spray methods and found that the atomized spray pyrolysis technique give films with high transparency. Dye adsorption per gram of TiO{sub 2} is 2.16 times higher in the sample produced by the ASP method when compared to the film produced by the hand spray method and is 1.60 times higher than that produced by the doctor-blading method using a commercially available TiO{sub 2} nanocrystalline paste. SEM studies show the presence of interconnected discrete particles in the film produced by the ASP method. The fill factor (ff) remains almost constant for the cells with thickness from 6 {mu}m to 13 {mu}m but the highest photovoltage and photocurrent were found in {approx}10 {mu}m film based DSC which gave 8.2% conversion efficiency at AM 1.5 irradiation for cells of 0.25 cm{sup 2} active area.

  7. Facile synthesis of silicon carbide-titanium dioxide semiconducting nanocomposite using pulsed laser ablation technique and its performance in photovoltaic dye sensitized solar cell and photocatalytic water purification

    Energy Technology Data Exchange (ETDEWEB)

    Gondal, M.A., E-mail: magondal@kfupm.edu.sa [Laser Research Group, Physics Department & Center of Excellence in Nanotechnology, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Ilyas, A.M. [Laser Research Group, Physics Department & Center of Excellence in Nanotechnology, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Baig, Umair [Laser Research Group, Physics Department & Center of Excellence in Nanotechnology, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Center of Excellence for Scientific Research Collaboration with MIT, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

    2016-08-15

    Highlights: • SiC–TiO{sub 2} semiconducting nanocomposites synthesized by nanosecond PLAL technique. • Synthesized nanocomposites were morphologically and optically characterized. • Nanocomposites were applied for the photocatalytic degradation of toxic organic dye. • Photovoltaic performance was investigated in dye sensitized solar cell. - Abstract: Separation of photo-generated charge carriers (electron and holes) is a major approach to improve the photovoltaic and photocatalytic performance of metal oxide semiconductors. For harsh environment like high temperature applications, ceramic like silicon carbide is very prominent. In this work, 10%, 20% and 40% by weight of pre-oxidized silicon carbide was coupled with titanium dioxide (TiO{sub 2}) to form nanocomposite semiconductor via elegant pulsed laser ablation in liquid technique using second harmonic 532 nm wavelength of neodymium-doped yttrium aluminium garnet (Nd-YAG) laser. In addition, the effect of silicon carbide concentration on the performance of silicon carbide-titanium dioxide nanocomposite as photo-anode in dye sensitized solar cell and as photocatalyst in photodegradation of methyl orange dye in water was also studied. The result obtained shows that photo-conversion efficiency of the dye sensitized solar cell was improved from 0.6% to 1.65% and the percentage of methyl orange dye removed was enhanced from 22% to 77% at 24 min under ultraviolet–visible solar spectrum in the nanocomposite with 10% weight of silicon carbide. This remarkable performance enhancement could be due to the improvement in electron transfer phenomenon by the presence of silicon carbide on titanium dioxide.

  8. A single-cell technique for the measurement of membrane potential, membrane conductance, and the efflux of rapidly penetrating solutes in Amphiuma erythrocytes.

    Science.gov (United States)

    Stoner, L C; Kregenow, F M

    1980-10-01

    We describe a single-cell technique for measuring membrane potential, membrane resistance, and the efflux of rapidly penetrating solutes such as Cl and H2O. Erythrocytes from Amphiuma means were aspirated into a Sylgard (Dow Corning Corp.)-coated capillary. The aspirated cell separated a solution within the capillary from a solution in the bath. Each of these two solutions was contiguous with approximately 5% of the total membrane surface. Microelectrodes placed concentrically within the capillary permit the measurement of intracellular voltage, specific membrane resistance, and the electrical seal between the two solutions. The intracellular voltage averaged -17.7 mV (pH 7.6) and changed as either intra- or extracellular chloride was varied. The average specific membrane resistance measured by passing current across the exposed membrane surface was 110 ohm-cm2. 36Cl and tritiated H2O fluxes (0.84 +/- 0.05 x 10(-6) M . cm-2 . min-1 and 6.4 +/- 1.5 x 10(-3) M . cm-2 . min-1, respectively) were determined by noting the rate at which isotope leaves the cell and crosses the membrane exposed to the bath. Our measured values for the flux of 36Cl and tritiated H2O approximate reported values for free-floating cells. 36Cl efflux, in addition, is inhibited by 4-acetamido-4'-isothiocyano-stilbene 2,2'-disulfonic acid (SITS) and furosemide, known inhibitors of the anion exchange mechanism responsible for the rapid anion fluxes of red blood cells. One can also demonstrate directly that > 89% of 36Cl efflux is "electrically silent" by analyzing the flux in the presence of an imposed transcellular voltage.

  9. High efficiency a-Si:H/a-SiGe:H tandem solar cells fabricated with the combination of V- and U-shaped band gap profiling techniques

    Science.gov (United States)

    Inthisang, Sorapong; Krajangsang, Taweewat; Hongsingthong, Aswin; Limmanee, Amornrat; Kittisontirak, Songkiate; Jaroensathainchok, Suttinan; Moolakorn, Apichan; Dousse, Adrien; Sritharathikhun, Jaran; Sriprapha, Kobsak

    2015-08-01

    Hydrogenated amorphous silicon germanium (a-SiGe:H) films prepared by very high frequency plasma-enhanced chemical vapor deposition (VHF-PECVD) using a mixture of SiH4, H2, and GeH4 were investigated for their use as the bottom cell of amorphous silicon/amorphous silicon germanium (a-Si:H/a-SiGe:H) tandem solar cell structures. Narrow optical band gaps (Eopt) in the range of 1.5 to 1.6 eV were obtained by varying the GeH4/(SiH4 + GeH4) gas flow rate ratio in low-temperature deposition. The a-SiGe:H films deposited with various GeH4/(SiH4 + GeH4) gas flow rate ratios were used as intrinsic layers for the a-Si:H/a-SiGe:H tandem solar cells with different graded band gaps: V-, VU-, and U-shapes. It was found that using the VU-shape improves the solar cell efficiency owing to a higher Jsc when compared with using V-shape. The VU-shape’s Voc and FF are also improved when compared with the U-shape’s Voc and FF. As a result, a high efficiency of 11.0% (Voc = 1.74 V, Jsc = 9.07 mA/cm2, and FF = 0.70) was successfully achieved with the solar cells fabricated using the VU-shape graded band gap technique.

  10. The Effect of the LysoPC-induced Endothelial Cell Conditioned Medium on Proliferating Cell Nuclear Antigen Expression of the Calf Thoracic Aorta Smooth Muscle Cells

    Institute of Scientific and Technical Information of China (English)

    周洪莲; 姚济华; 余枢

    2002-01-01

    In order to study the effect of and mechanism of lysophosphatidylcholine (LysoPC) on proliferation of the calf thoracic aorta smooth muscle cells (ASMCs), the ASMCs were used to observe the effects of LysoPC-induced endothelial cell conditioned medium on the DNA content and proliferating cell nuclear antigen (PCNA) expression in the calf thoracic ASMCs by flow cytometry and Western Blot technique. It was found that LysoPC-induced endothelial cell conditioned medium could significantly promote PCNA expression of the calf ASMCs, induce the converting of ASMCs from G0/G1 phase to S phase of DNA synthesis, and increase the tyrosine phosphorylation protein expression. Tyrosine protein kinase inhibitor (TPKi) RG50864 could obviously inhibit proliferation of LysoPC-induced ASMCs in a dose-dependence manner. The results indicated that the effect of LysoPC promoting the proliferation of ASMCs is partly evoked by endothelial cell derived growth factors such as PDGF and so on.

  11. Glycophospholipid Formulation with NADH and CoQ10 Significantly Reduces Intractable Fatigue in Western Blot-Positive ‘Chronic Lyme Disease’ Patients: Preliminary Report

    Directory of Open Access Journals (Sweden)

    Garth L. Nicolson

    2012-03-01